HK1136949A - Energy delivery systems and uses thereof - Google Patents

Description

Energy transmission system and use thereof

Technical Field

The present invention relates to integrated systems, devices, and methods for delivering energy to tissue for a variety of applications, including medical procedures (e.g., tissue ablation, resection, cautery, vascular thrombosis, treatment of cardiac arrhythmias and dysrhythmias, electrosurgery, tissue harvest, etc.). In some embodiments, systems, devices, and methods are provided for treating a tissue region (e.g., a tumor) by application of energy.

Background

Ablation is an important therapeutic strategy for the treatment of certain tissues, such as benign and malignant tumors, cardiac arrhythmias and tachycardia. Many approved ablation systems use Radio Frequency (RF) energy as the ablation energy source. Thus, physicians currently have access to a wide variety of RF-based catheters and power sources. However, there are several limitations to RF energy, including the rapid dissipation of energy in surface tissue, resulting in shallow "ablation", and the inability to access deeper tumors or arrhythmic tissue. Another limitation of RF ablation systems is the tendency for eschar and blood clots to form on the energy emitting electrode, which limits further deposition of electrical energy.

Microwave energy is an effective energy source for heating biological tissue for applications such as cancer treatment and preheating blood prior to perfusion. Therefore, in view of the shortcomings of conventional ablation techniques, there has been a great deal of interest in recent years in using microwave energy as the source of ablation energy. The advantages of microwave energy over RF are deeper penetration into the tissue, less charring, no grounding necessary, more reliable energy deposition, faster tissue heating, and the ability to produce much greater thermal damage than RF (which greatly simplifies the actual ablation process). Accordingly, various devices are being developed that utilize electromagnetic energy in the microwave frequency range as a source of ablation energy (see, for example, U.S. Pat. Nos. 4,641,649, 5,246,438, 5,405,346, 5,314,466, 5,800,494, 5,957,969, 6,471,696, 6,878,147, and 6,962,586, each of which is hereby incorporated by reference in its entirety).

Unfortunately, current devices for transmitting microwave energy have drawbacks. For example, current devices produce relatively little damage due to practical limitations in power and treatment time. Current devices have power limitations because the power carrying capacity of the feeder is small. However, larger diameter feedlines are undesirable because they are less easily inserted percutaneously and can increase procedural complication rates. For most applications, microwave devices are also limited to a single antenna, thereby limiting the ability to treat multiple areas simultaneously, or to arrange several antennas in close proximity to create a large heated area of tissue. In addition, heating of the feed line at high power can cause burns around the device insertion area.

There is a need for improved systems and devices for delivering energy to a tissue region. In addition, there is a need for improved systems and apparatus that are capable of transmitting microwave energy without a corresponding loss of microwave energy. In addition, there is a need for systems and devices that are capable of percutaneously delivering microwave energy to the tissue of a subject without undesirable tissue burns. Further, there is a need for a system that transmits a desired amount of microwave energy without the need for physically large invasive components.

Disclosure of Invention

The present invention relates to integrated single and multiple antenna systems, devices, and methods for delivering energy to tissue for a variety of applications, including medical procedures (e.g., tissue ablation, resection, cautery, vascular thrombosis, treatment of cardiac arrhythmias and dysrhythmias, electrosurgery, tissue harvest, etc.). In some embodiments, systems, devices, and methods are provided for treating a tissue region (e.g., a tumor) by application of energy.

The present invention provides systems, devices and methods for delivering energy to a tissue region (e.g., tumor, lumen, organ, etc.) using an assembly. In some embodiments, the system comprises an energy transfer device and one or more of: a processor, a power source, a power splitter, an imaging system, a tuning system, and a temperature regulation system.

The invention is not limited to a particular type of energy transmission device. The present invention contemplates the use of any known or future developed energy transmission device in the system of the present invention. In some embodiments, existing commercial energy transmission equipment is utilized. In other embodiments, an improved energy delivery device is used that has optimized characteristics (e.g., small size, optimized energy delivery, optimized impedance, optimized heat dissipation, etc.). In some such embodiments, the energy delivery device is configured to deliver energy (e.g., microwave energy) to the tissue region. In some embodiments, the energy delivery device is configured to deliver microwave energy at an optimized characteristic impedance (e.g., configured to operate at a characteristic impedance higher than 50 Ω) (e.g., between 50 and 90 Ω; e.g., greater than 50, 55, 56, 57, 58, 59, 60, 61, 62, 90 Ω, preferably 77 Ω) (e.g., see U.S. patent application serial No.11/728,428; incorporated herein by reference in its entirety).

One major source of unwanted overheating of the device is dielectric heating of the insulator, which can lead to tissue damage. The energy transfer device of the present invention is designed to prevent undesired overheating of the device. The energy transfer device is not limited to a particular manner of preventing overheating of the device. In some embodiments, the apparatus employs circulation of a coolant. In some embodiments, the device is configured to detect an undesirable temperature rise within the device (e.g., along the outer conductor) and automatically or manually reduce such an undesirable temperature rise by flowing a coolant through the cooling channel.

In some embodiments, the energy transfer device has improved cooling characteristics. For example, in some embodiments, the apparatus allows for the use of coolant without increasing the diameter of the apparatus. This is in contrast to prior devices that flowed coolant through an external sleeve or otherwise increased the diameter of the device to accommodate the flow of coolant. In some embodiments, one or more cooling channels are provided in the energy delivery device to reduce undesirable heat dissipation (see, for example, U.S. patent application serial No.11/728,460; incorporated herein by reference in its entirety). In some embodiments, the energy transfer device has a tube (e.g., a needle, plastic tubing, etc.) therein that extends along the entire length or a portion of the length of the device for avoiding overheating of the device by circulation of the cooling material. In some embodiments, the channel or tube replaces the material of the dielectric assembly located between the inner and outer conductors of the coaxial cable. In some embodiments, the channel or tube replaces or substantially replaces the dielectric material. In some embodiments, a channel or tube replaces a portion of the outer conductor. For example, in some embodiments, a portion of the outer conductor is removed or shaved off, thereby creating a flow channel for the coolant. One such embodiment is shown in fig. 12. In this embodiment, the coaxial cable 900 has an outer conductor 910, an inner conductor 920, and a dielectric material 930. In this embodiment, the dielectric material region 940 is removed, forming a coolant flow space. The only outer conductor material remaining around or substantially around the coaxial cable is located at the distal end region 950 and the proximal end region 960. A thin strip of conductive material 970 connects the distal region 950 and the proximal region 960. In this embodiment, a thin channel 980 is cut from the conductive material at the proximal region 960 to allow coolant to flow into the region 940 where the outer conductive material is removed (or processed so that no outer conductive material is present). The present invention is not limited by the size or shape of the channels as long as coolant can be delivered. For example, in some embodiments, the channel is a linear path extending along the length of the coaxial cable. In some embodiments, a spiral channel may be employed. In some embodiments, the tube or channel removes or replaces at least a portion of the inner conductor. For example, most of the inner conductor may be replaced with cooling channels, leaving only a small portion of metal near the proximal and distal ends of the device for tuning, where the remaining metal portions are connected by a thin strip of conductive material. In some embodiments, an interior space region is formed within the inner conductor or the outer conductor to form one or more channels for the coolant. For example, the inner conductor may be provided in the form of a hollow tube of conductive material, with the cooling channel being provided centrally. In such embodiments, the inner conductor may be used for inflow or outflow (or both inflow and outflow) of the coolant.

In some embodiments, where the cooling tube is placed within the device, the cooling tube has multiple channels for coolant flow into and out of the device. The apparatus is not limited to a particular arrangement of cooling tubes (e.g., cooling pins) within the dielectric material. In some embodiments, the cooling tubes are disposed along the outer edges of the dielectric material, in the middle of the dielectric material, or anywhere within the dielectric material. In some embodiments, the dielectric material is pre-formed with channels designed to receive and secure cooling tubes. In some embodiments, a handle is coupled to the device, wherein the handle is configured to control the flow of coolant into and out of the cooling tube. In some embodiments, the cooling tube is flexible. In some embodiments, the cooling tube is inflexible. In some embodiments, portions of the cooling tube are flexible, while other portions are inflexible. In some embodiments, the cooling tube is compressible. In some embodiments, the cooling tube is incompressible. In some embodiments, portions of the cooling tube are compressible, while other portions are incompressible. The cooling tube is not limited to a particular shape or size. In some embodiments, the cooling tube is a cooling pin (e.g., a 29 gauge pin or equivalent size) secured within a coaxial cable having a diameter equal to or less than a 12 gauge pin. In some embodiments, the exterior of the cooling tube has a layer of adhesive and/or grease to secure the cooling tube or to allow sliding within the device. In some embodiments, the cooling tube has one or more holes along its length that allow for the release of coolant into a desired area of the device. In some embodiments, the orifices are initially plugged with a fusible material such that a particular heat threshold is required to melt the material and release the coolant through the particular orifice or orifices affected. Thus, the coolant is released only in the region where the heat threshold has been reached.

In some embodiments, the coolant is pre-loaded into the antenna, handle, or other component of the device of the present invention. In other embodiments, the coolant is added during use. In some pre-loaded embodiments, the liquid coolant is pre-loaded into the distal end of the antenna, for example, under the formation of a self-sustaining vacuum. In some such embodiments, the vacuum draws in more fluid as the liquid coolant evaporates.

The invention is not limited by the nature of the cooling material employed. Coolants include, but are not limited to, liquids and gases. Exemplary coolant fluids include, but are not limited to, one or more or a combination of the following: water, glycols, air, inert gases, carbon dioxide, nitrogen, helium, sulfur hexafluoride, ionic solutions (e.g., sodium chloride with or without potassium and other ions), aqueous dextrose, ringer's lactate, organic chemical solutions (e.g., ethylene glycol, diethylene glycol, or propylene glycol), oils (e.g., mineral oil, silicone oil, fluorocarbon oil)Liquid metal, freon, methyl halide, liquefied propane, other halogenated alkanes, anhydrous ammonia, sulfur dioxide. In some embodiments, refrigeration occurs at least in part by changing the concentration, pressure, or volume of the coolant. Cooling may be achieved, for example, by means of a gaseous coolant which utilises the Joule-Thompson effect. In some embodiments, the cooling is provided by a chemical reaction. The apparatus is not limited to a particular type of temperature-reducing chemical reaction. In some embodiments, the temperature-decreasing chemical reaction is an endothermic reaction. The apparatus is not limited to a particular manner of applying endothermic reactions to prevent undesired heating. In some embodiments, the first and second chemicals are flowed into the device such that they react with each other, thereby reducing the temperature of the device. In some embodiments, the device is prepared with the first and second chemicals preloaded into the device. In some embodiments, the chemicals are separated by spacers that are removed when needed. In some embodiments, the separator is configured to melt when exposed to a predetermined temperature or temperature range. In such embodiments, the device initiates the endothermic reaction only when a heat level is reached that is worth cooling. In some embodiments, a plurality of different spacers are located throughout the device such that localized cooling occurs only in those portions of the device where undesirable heat generation occurs. In some embodiments, the separator used is a pellet containing one of the two chemicals. In some embodiments, the spacer is a wall (e.g., a washer-shaped disk) that melts to bond the two chemicals. In some embodiments, the spacer is made of wax that melts at a predetermined temperature. The device is not limited to a particular type, type or amount of fusible material. In some embodiments, the fusible material is biocompatible. The apparatus is not limited to a particular type, type or amount of first and second chemicals, as long as their combination results in a temperature-reducing chemical reaction. In some embodiments, the first material comprises barium hydroxide octahydrate crystals and the second material is dry ammonium chloride. In some embodiments, the first material is water and the second material is ammonium chloride. In some embodiments, the first material is thionyl chloride (SOCl)₂) The second material is sevenCobalt (II) sulfate hydrate. In some embodiments, the first material is water and the second material is ammonium nitrate. In some embodiments, the first material is water and the second material is potassium chloride. In some embodiments, the first material is acetic acid and the second material is sodium carbonate. In some embodiments, a meltable material is used that reduces heat by itself by melting the flow in a manner that reduces the heat of the exterior surface of the device.

In some embodiments, the energy transfer device prevents undesired heating and/or maintains desired energy transfer properties by adjusting the amount of energy emitted from the device as the temperature increases (e.g., adjusting the energy wavelength at which the slave device resonates). The device is not limited to a particular method of adjusting the amount of energy emitted from the device. In some embodiments, the device is configured such that the energy wavelength at which the slave device resonates is adjusted when the device reaches a certain threshold temperature, or when the device heats up beyond a certain range. The device is not limited to a particular method of tuning the energy wavelength at which the slave device resonates. In some embodiments, the device has a material therein that changes volume as the temperature increases. The change in volume is used to move or adjust components of the device that affect energy transfer. For example, in some embodiments, a material that expands with increasing temperature is used. The expansion is used to move the distal end of the device outward (increasing its distance from the proximal end of the device), changing the energy transmission properties of the device. This is particularly useful for the center-fed dipole embodiment of the present invention.

In some embodiments, the present invention provides an apparatus comprising an antenna for delivering energy to tissue, wherein a distal end of the antenna comprises a center-fed dipole assembly comprising a rigid hollow tube housing a conductor, wherein a probe is secured within the hollow tube. In some embodiments, the hollow tube has a diameter equal to or less than a 20 gauge needle. In some embodiments, the hollow tube has a diameter equal to or less than a 17 gauge needle. In some embodiments, the hollow tube has a diameter equal to or less than a 12 gauge needle. In some embodiments, the device further comprises a tuning element that adjusts the amount of energy delivered to the tissue. In some embodiments, the device is configured to deliver a sufficient amount of energy to ablate tissue or cause thrombosis. In some embodiments, the conductor extends partially within the hollow tube. In some embodiments, the hollow tube has a length λ/2, where λ is the wavelength of the electromagnetic field within the tissue medium. In some embodiments, a swellable material is placed in proximity to the probe such that when the temperature of the device increases, the swellable material expands, pushes the probe, and changes the energy transmission properties of the device. In some embodiments, the swellable material is positioned behind (adjacent to) the metal disk that provides the resonating element for the center-fed dipole device. When the expandable material expands, the metal disc is pushed distally, adjusting the tuning of the device. The expandable material is preferably selected so that the rate of expansion is matched to the desired change in energy transmission to achieve optimal results. It should be understood, however, that any variation of the desired orientation may be used with the present invention. In some embodiments, the expandable material is a wax.

In some embodiments, the device has a handle connected to the device, wherein the handle is configured to, for example, control the flow of coolant into and out of the cooling channel. In some embodiments, only the handle is cooled. In other embodiments, the handle and attached antenna are cooled. In some embodiments, the handle automatically moves coolant into and out of the cooling channel after a certain time and/or when the device reaches a certain threshold temperature. In some embodiments, the handle automatically stops coolant from entering and exiting the cooling channel after a certain time and/or when the temperature of the device drops to a certain threshold temperature. In some embodiments, coolant flow through the handle is manually controlled.

In some embodiments, a center-fed dipole assembly is provided in the energy delivery device (see, e.g., U.S. patent application serial No.11/728,457; incorporated herein by reference in its entirety). In some embodiments, the energy transmission device includes a catheter having multiple segments that transmit and emit energy (see, e.g., U.S. patent application nos. 11/237,430, 11/237,136, and 11/236,985; all of which are incorporated herein by reference in their entirety). In some embodiments, the energy transmission device includes a tri-axial microwave probe with optimized tuning capabilities to reduce reflected heat loss (see, e.g., U.S. patent No. 7,101,369; see, additionally, U.S. patent application nos. 10/834,802, 11/236,985, 11/237,136, 11/237,430, 11/440,331, 11/452,637, 11/502,783, 11/514,628; and international patent application No. PCT/US 05/14534; all of which are incorporated herein by reference in their entirety). In some embodiments, the energy transmission device emits energy through a coaxial transmission line (e.g., a coaxial cable) having air or other gas as a dielectric core (see, e.g., U.S. patent application No. 11/236,985; incorporated herein by reference in its entirety). In some such embodiments, material supporting the device structure between the inner and outer conductors may be removed prior to use. For example, in some embodiments, the material is made of a dissolvable or meltable material that is removed prior to or during use. In some embodiments, the material is meltable and is removed in use (when exposed to heat) in order to optimize the energy transmission properties of the device over time (e.g., in response to temperature changes in tissue, etc.).

The present invention is not limited to a particular coaxial transmission line shape. Indeed, in some embodiments, the shape of the coaxial transmission line and/or the dielectric element is adjustable to suit particular needs. In some embodiments, the cross-sectional shape of the coaxial transmission line and/or the dielectric element is circular. In some embodiments, the cross-sectional shape is not circular (e.g., oval, etc.). This shape may be applied to the entire coaxial cable, or may be applied to only one or more subassemblies. For example, an elliptical dielectric material may be placed in a circular outer conductor. This has the advantage that two channels are formed which can be used for circulating the coolant. As another example, a square/rectangular dielectric material may be disposed in a circular outer conductor. This has the advantage that four channels can be formed. Different polygonal shapes of cross-section (e.g., pentagonal, hexagonal, etc.) may be employed to form different numbers and shapes of channels. The cross-sectional shape need not be the same throughout the length of the cable. In some embodiments, a first shape is applied to a first region (e.g., a proximal region) of the cable and a second shape is applied to a second region (e.g., a distal region) of the cable. Irregular shapes may also be used. For example, a dielectric material having indented grooves extending along its length may be employed in a circular outer conductor to form a single channel of any desired size and shape. In some embodiments, the channels form spaces for coolant, needles, or other desired components to be packed into the device without increasing the final outer diameter of the device.

Likewise, in some embodiments, the antenna of the present invention has a non-circular cross-sectional shape along its length or for one or more segments of its length. In some embodiments, the antenna is not a cylinder, but includes a coaxial cable that is a cylinder. In other embodiments, the antenna is not cylindrical and includes a coaxial cable that is not cylindrical (e.g., matches the shape of the antenna, or has a different non-cylindrical shape). In some embodiments, having any one or more components with a non-cylindrical shape (e.g., a sleeve, a housing of an antenna, an outer conductor of a coaxial cable, a dielectric material of a coaxial cable, an inner conductor of a coaxial cable), among other reasons, allows for the formation of one or more channels in the apparatus that may be used to circulate a coolant. Non-circular shapes, particularly with respect to the outer diameter of the antenna, may also be useful for certain medical or other applications. For example, a shape may be selected to maximize flexibility or to approximate a particular location within the body. The shape may also be selected to optimize energy transfer. The shape (e.g., non-cylindrical shape) may also be selected to maximize the rigidity and/or strength of the device, particularly small diameter devices.

In some embodiments, the present invention provides an apparatus comprising an antenna, wherein the antenna comprises an outer conductor surrounding an inner conductor, wherein the inner conductor is configured to receive and transmit energy, wherein the outer conductor has at least one gap therein disposed circumferentially along the outer conductor, wherein a plurality of energy peaks are generated along a length of the antenna, the position of the energy peaks being controlled by the position of the gap. In some embodiments, the energy is microwave energy and/or radiofrequency energy. In some embodiments, there are two gaps in the outer conductor. In some embodiments, the antenna includes a dielectric layer disposed between the inner conductor and the outer conductor. In some embodiments, the dielectric layer has a conductivity close to zero. In some embodiments, the apparatus further comprises a probe. In some embodiments, the inner conductor has a diameter of about 0.013 inches or less.

In some embodiments, any gaps or inconsistencies or irregularities in the outer conductor or outer surface of the device are filled with material to form a smooth, uniform or substantially smooth, uniform outer surface. In some embodiments, heat resistant resins are used to fill gaps, inconsistencies, and/or irregularities. In some embodiments, the resin is biocompatible. In other embodiments, the resins are biocompatible, but may be coated with a biocompatible material. In some embodiments, the resin may be configured in any desired size or shape. Thus, when hardened, the resin may be used to provide a sharp probe tip of the device, or any other desired physical shape.

In some embodiments, the device comprises a sharp probe tip. The tip may be made of any material. In some embodiments, the tip is made of a hardened resin. In some embodiments, the tip is a metal. In some such embodiments, the metal tip is an extension of the metal portion of the antenna and is electrically active.

In some embodiments, the energy delivery device is configured to deliver energy to the tissue region within a system that includes a processor, a power source, a power splitter with the ability to individually control the delivery of power to each antenna, an imaging system, a tuning system, and/or a temperature adjustment system.

The invention is not limited to a particular type of processor. In some embodiments, the processor is used to receive information from components of the system, e.g., temperature monitoring systems, energy delivery devices, tissue impedance monitoring components, etc., display such information to a user, and operate (e.g., control) other components of the system. In some embodiments, the processor is configured to operate within a system that includes an energy delivery device, a power source, a power splitter, an imaging system, a tuning system, and/or a temperature adjustment system.

The present invention is not limited to a particular type of power source. In some embodiments, the power source is configured to provide any desired type of energy (e.g., microwave energy, radiofrequency energy, radiation, cryoenergy, electroporation, high intensity focused ultrasound, and/or mixtures thereof). In some embodiments, the power source utilizes a power splitter to allow energy to be delivered to two or more energy delivery devices. In some embodiments, the power source is configured to operate within a system that includes a power splitter, a processor, an energy delivery device, an imaging system, a tuning system, and/or a temperature adjustment system.

The present invention is not limited to a particular type of imaging system. In some embodiments, the imaging system utilizes an imaging device (e.g., an endoscopic device, a stereotactic computer-assisted neurosurgical navigation device, a thermal sensor positioning system, a motion rate sensor, a guidewire system, intraoperative ultrasound, fluoroscopy, computerized tomography magnetic resonance imaging, nuclear medicine imaging device triangulation, thermoacoustic imaging, infrared and/or laser imaging, electromagnetic imaging) (see, e.g., U.S. patent nos. 6,817,976, 6,577,903 and 5,697,949, 5,603,697, and international patent application No. WO06/005,579; all of which are incorporated herein by reference in their entirety). In some embodiments, the system utilizes an endoscopic camera, an imaging assembly, and/or a navigation system that allows or facilitates placement, positioning, and/or monitoring of any item used with the energy system of the present invention. In some embodiments, the imaging system is configured to provide location information of a particular component of the energy delivery system (e.g., the location of the energy delivery device). In some embodiments, the imaging system is configured to operate within a system that includes a processor, an energy delivery device, a power source, a tuning system, and/or a temperature adjustment system.

The invention is not limited to a particular tuning system. In some embodiments, the tuning system is configured to allow for adjustment of variables (e.g., amount of energy delivered, frequency of energy delivered, energy delivered to one or more of a plurality of energy devices disposed in the system, amount or type of coolant provided, etc.) within the energy delivery system. In some embodiments, the tuning system includes a sensor that continuously or at multiple points in time provides feedback to a user or to a processor that monitors the functionality of the energy delivery device. The sensors may record and/or report any number of properties, including (but not limited to) heating at one or more locations of a component of the system, heating at tissue, a property of tissue, and so forth. The sensor may take the form of an imaging device such as CT, ultrasound, magnetic resonance imaging, fluoroscopy, nuclear medicine imaging or any other imaging device. In some embodiments, particularly for research applications, the system records and maintains information for future optimization of the system, and/or optimization of energy delivery under specific conditions (e.g., patient type, tissue type, size and shape of target region, location of target region, etc.). In some embodiments, the tuning system is configured to operate within a system that includes a processor, an energy delivery device, a power source, an imaging system, and/or a temperature adjustment system. In some embodiments, an imaging or other control component provides feedback to the ablation device so that the power output (or other control parameter) can be adjusted to provide an optimal tissue response.

The present invention is not limited to a particular temperature adjustment system. In some embodiments, the temperature adjustment system is used to reduce undesirable heating of various components of the system (e.g., energy delivery device) during a medical procedure (e.g., tissue ablation), or to maintain target tissue within a certain temperature range. In some embodiments, the temperature adjustment system is configured to operate within a system comprising a processor, an energy delivery device, a power source, a power divider, a tuning system, and/or an imaging system.

In some embodiments, the system further includes a temperature monitoring or reflected power monitoring system that monitors the temperature or reflected power of various components of the system (e.g., the energy transmission device) and/or the tissue region. In some embodiments, the monitoring system is used to alter (e.g., prevent, reduce) energy transmission to a particular tissue region if the temperature or the amount of reflected energy exceeds a predetermined value. In some embodiments, the temperature monitoring system is used to alter (e.g., increase, decrease, maintain) the energy delivery to a particular tissue region in order to maintain the tissue or energy delivery device at a preferred temperature or within a preferred temperature range.

In some embodiments, the system further includes an identification or tracking system that prevents the use of previously used components (e.g., non-sterile energy transfer devices), identifies the nature of the components of the system so that other components of the system can be properly adjusted for compatibility or optimized function. In some embodiments, the system reads a bar code or other information conveying element associated with a component of the system of the present invention.

The invention is not limited by the type of components used in the system or the application used. In fact, the device may be configured in any desired manner. Likewise, the systems and devices may be used in any application where energy is to be delivered. Such applications include any medical, veterinary and research applications. However, the systems and apparatus of the present invention may be used in agricultural environments, manufacturing environments, mechanical environments, or any other application where energy is to be transferred.

In some embodiments, the system is configured for percutaneous, intravascular, intracardiac, laparoscopic, or surgical delivery of energy. In some embodiments, the system is configured to deliver energy to a target tissue or region. The invention is not limited by the nature of the target tissue or region. Uses include, but are not limited to, treatment of cardiac arrhythmias, tumor ablation (benign and malignant), control of intraoperative hemorrhage, control of traumatic hemorrhage, any other bleeding control, removal of soft tissue, tissue removal and resection, treatment of varicose veins, intraluminal tissue ablation (e.g., treatment of esophageal lesions such as Barrett's esophagus and esophageal adenoma), treatment of bone tumors, normal skeletal and benign bone conditions, intraocular applications, applications in cosmetic surgery, treatment of central nervous system lesions (including brain tumors and electrical disorders), sterilization procedures (e.g., ablation of fallopian tubes), and cauterization of blood vessels or tissues of any purpose. In some embodiments, the surgical application includes ablation therapy (e.g., to achieve coagulative necrosis). In some embodiments, the surgical application includes tumor ablation of a target, such as a metastatic tumor. In some embodiments, the device is configured to be moved and positioned at any desired location, including (but not limited to) the brain, neck, chest, abdomen, and pelvis, with minimal damage to the tissue or organ. In some embodiments, the system is configured to achieve directional transmission by computerized tomography, ultrasound, magnetic resonance imaging, fluoroscopy, or the like.

In some embodiments, the present invention provides methods of treating a tissue region, comprising providing a tissue region and a system described herein (e.g., an energy delivery device, and at least one of a processor, a power source, a power splitter, a temperature monitor, an imager, a tuning system, and/or a cooling system); positioning a portion of an energy delivery device proximate to the tissue region, and delivering an amount of energy to the tissue region with the energy delivery device. In some embodiments, the tissue region is a tumor. In some embodiments, the delivery of energy results in ablation of the tissue region and/or embolization of blood vessels, and/or electroporation of the tissue region. In some embodiments, the tissue region is a tumor. In some embodiments, the tissue region comprises one or more of a heart, liver, genitalia, stomach, lung, large intestine, small intestine, brain, neck, bone, kidney, muscle, tendon, blood vessel, prostate, bladder, and spinal cord. In some embodiments, a processor receives information from sensors and monitors and controls other components of the system. In some embodiments, the energy output of the power source is varied as appropriate to achieve optimal treatment. In some embodiments where more than one energy transmission assembly is provided, the amount of energy delivered to each energy transmission assembly is optimized to achieve the desired result. In some embodiments, the temperature of the system is monitored by a temperature sensor, and the temperature is reduced by activating a cooling system when the temperature reaches or approaches a threshold value. In some embodiments, the imaging system provides information to the processor that is displayed to a user of the system and can be used in a feedback loop to control the output of the system.

In some embodiments, energy is delivered to the tissue region at different intensities and from different locations within the device. For example, certain regions of a tissue region may be treated by one portion of the device while other regions of tissue are treated by a different portion of the device. In addition, two or more regions of the device may simultaneously deliver energy to a particular tissue region in order to achieve constructive phase interference (e.g., the emitted energy achieves a synergistic effect). In other embodiments, two or more regions of the apparatus may transmit energy in order to achieve a destructive interference effect. In some embodiments, the method further provides an auxiliary device for achieving constructive and/or destructive phase interference. In some embodiments, phase interference (e.g., constructive phase interference, destructive phase interference) between one or more devices is controlled by a processor, tuning element, user, and/or power splitter.

The systems, devices, and methods of the present invention may be used with other systems, devices, and methods. For example, the systems, devices, and methods of the present invention may be used with other ablation devices, other medical devices, diagnostic methods and agents, imaging methods and agents, and therapeutic methods and agents. The use may be simultaneous, or occur before or after another intervention. The present invention contemplates the use of the systems, devices and methods of the present invention with any other medical intervention.

In addition, there is a need for an integrated ablation and imaging system that provides feedback to the user and allows communication between the various system components. System parameters can be adjusted during the ablation process to optimize energy delivery. In addition, the user is able to more accurately determine when the treatment procedure is successfully completed, reducing the likelihood of unsuccessful treatment and/or treatment-related complications.

Drawings

Fig. 1 shows a schematic view of an energy transfer system in an embodiment of the invention.

Fig. 2 illustrates various shapes of coaxial transmission lines and/or dielectric elements in some embodiments of the invention.

Fig. 3A and 3B show coaxial transmission line embodiments having a segmented section with first and second materials separated by a fusible wall to prevent unwanted device heating (e.g., heating along the outer conductor).

Fig. 4A and 4B show coaxial transmission line embodiments having segmented sections separated by fusible walls comprising first and second materials (the materials configured to produce a temperature-reducing chemical reaction when mixed) that prevent unwanted device heating (e.g., heating along the outer conductor).

FIG. 5 shows a schematic view of a handle configured to control the flow of coolant into and out of the cooling gallery.

Fig. 6 shows a schematic cross-sectional view of an embodiment of a coaxial cable having cooling channels.

Fig. 7 shows a coolant circulation tube (e.g., cooling needle, catheter) disposed within an energy emitting device having an outer conductor and a dielectric material.

Fig. 8 schematically illustrates the distal end of a device of the present invention (e.g., an antenna of an ablation device) incorporating a center-fed dipole assembly of the present invention.

Figure 9 shows the test setup and position of the temperature measurement station. As shown, the ablation needle axis was 20.5cm for all experiments. Probes 1,2 and 3 are located adjacent to the tips of the stainless steel needles at 4,8 and 12 cm.

Figure 10 shows treatment at 35% of reflected power (from 13:40 to 13:50, microwave "on") with abnormally high (6.5%). The probe 3 is initially placed in air just outside the liver tissue.

Figure 11 shows a 10 minute treatment at 45% of reflected power (from 14:58 to 15:08, microwave "on") with an abnormally high (6.5%) reflected power. The peak temperature of station 4 is 40.25 ℃.

Fig. 12 shows a coaxial cable with a portion of its outer conductor removed to create a coolant flow space in one embodiment of the invention.

FIG. 13 is a schematic diagram of an input/output box, a transfer sleeve, and a process equipment hub.

Detailed Description

The present invention relates to integrated systems, devices and methods for delivering energy (e.g., microwave energy, radio frequency energy) to tissue for a variety of applications, including medical procedures (e.g., tissue ablation, resection, cautery, vascular thrombosis, intraluminal ablation of hollow organs, cardiac ablation to treat cardiac arrhythmias, electrosurgery, tissue resection, cosmetic surgery, intraocular applications, etc.). In particular, the present invention provides a system for transmitting microwave energy, including a power source, a power divider, a processor, an energy emitting device, a cooling system, an imaging system, a temperature monitoring system, and/or a tracking system. In some embodiments, systems, devices and methods are provided for treating a tissue region (e.g., a tumor) by using the energy delivery systems of the present invention.

The system of the present invention may be incorporated into a variety of system/kit embodiments. For example, the present invention provides a system comprising one or more of a generator, a power distribution system, a power distributor, an energy applicator, and any one or more accessory components (e.g., surgical instruments, software participating in a therapeutic procedure, processors, temperature monitoring devices, etc.). The present invention is not limited to any particular accessory assembly.

The system of the present invention may be used in any medical procedure (e.g., percutaneous or surgical procedures) involving the delivery of energy to a tissue region. The system is not limited to treating a particular type or kind of tissue region (e.g., brain, liver, heart, blood vessels, feet, lungs, bone, etc.). For example, the system of the present invention finds application in ablating a tumor region. Other treatments include, but are not limited to, treatment of cardiac arrhythmias, tumor ablation (benign and malignant), control of intraoperative hemorrhage, control of traumatic hemorrhage, any other bleeding control, removal of soft tissue, tissue removal and resection, treatment of varices, intraluminal tissue ablation (e.g., treatment of esophageal lesions such as Barrett's esophagus and esophageal adenoma), treatment of bone tumors, normal skeletal and benign bone conditions, intraocular applications, applications in cosmetic surgery, treatment of central nervous system lesions (including brain tumors and electrical disorders), sterilization procedures (e.g., ablation of fallopian tubes), and cauterization of blood vessels or tissues for any purpose. In some embodiments, the surgical application includes ablation therapy (e.g., to achieve coagulative necrosis). In some embodiments, the surgical application comprises tumor ablation of a target, such as a primary tumor or a metastatic tumor. In some embodiments, the surgical procedure includes control of bleeding (e.g., electrocautery). In some embodiments, the surgical application comprises tissue cutting or resection. In some embodiments, the device is configured to be moved and positioned at any desired location, including (but not limited to) the brain, neck, chest, abdomen, pelvis, and extremities, with minimal damage to the tissue or organ. In some embodiments, the device is configured to guide the transmission by computerized tomography, ultrasound, magnetic resonance imaging, fluoroscopy, or the like.

The exemplary embodiments provided below illustrate the system of the present invention using a medical application (e.g., ablating tissue by the transmission of microwave energy). It should be appreciated, however, that the system of the present invention is not limited to medical applications. The system may be used in any environment that requires energy to be delivered to a load (e.g., agricultural environments, manufacturing environments, research environments, etc.). The exemplary embodiments utilize microwave energy to describe the system of the present invention. It should be appreciated that the system of the present invention is not limited to a particular type of energy (e.g., radio frequency energy, microwave energy, focused ultrasound energy, laser, plasma).

The system of the present invention is not limited to any particular component or number of components. In some embodiments, the system of the present invention includes (but is not limited to including) a power source, a power divider, a processor, an energy delivery device with an antenna, a cooling system, an imaging system, and/or a tracking system. When multiple antennas are used, the system can be used to control each antenna independently.

FIG. 1 shows an exemplary system of the present invention. As shown, the energy delivery system includes a power source, a transmission line, a power distribution assembly (e.g., a power splitter), a processor, an imaging system, a temperature monitoring system, and an energy delivery device. In some embodiments, as shown, the components of the energy transmission system are connected via transmission lines, cables, and the like. In some embodiments, the energy delivery device is separate from the power source, power distributor, processor, imaging system, temperature monitoring system across the sterile zone barrier.

Exemplary components of the energy transfer system are described in more detail in the following sections: I. a power source; an energy transmission device; III, a processor; an imaging system; v. tuning the system; VI, a temperature adjustment system; VII, a recognition system; viii, a temperature monitoring device; and IX..

I. Power source

The energy used in the energy transmission system of the present invention is supplied by a power source. The present invention is not limited to a particular type or kind of power source. In some embodiments, the power source is configured to provide energy to one or more components of the energy delivery system of the present invention (e.g., an ablation device). The power source is not limited to a particular type of energy (e.g., radiofrequency energy, microwave energy, radiant energy, laser, focused ultrasound, etc.). The power source is not limited to providing a specific amount of energy or providing energy at a specific delivery rate. In some embodiments, the power source is configured to provide energy to an energy delivery device for tissue ablation.

The present invention is not limited to a particular type of power source. In some embodiments, the power source is configured to provide a desired type of energy (e.g., microwave energy, radiofrequency energy, radiation, cryoenergy, electroporation, high intensity focused ultrasound, and/or mixtures thereof). In some embodiments, the type of energy provided by the power source is microwave energy. In some embodiments, the power source provides microwave energy to an ablation device for tissue ablation. There are numerous advantages to using microwave energy in tissue ablation. For example, microwaves have a wide power density field (e.g., about 2 centimeters around the antenna depending on the wavelength of the applied energy), and a correspondingly large effective heating zone, thereby facilitating uniform tissue ablation both within the target zone and in the perivascular region (see, e.g., International application No. WO 2006/004585; incorporated herein by reference in its entirety). In addition, microwave energy has the ability to ablate larger tissue regions or multiple regions of tissue with multiple probes, while the tissue heats up faster. Microwave energy has the ability to penetrate tissue, creating deeper lesions with less surface heating. The energy delivery time is short compared to radiofrequency energy, and the probe is able to heat the tissue sufficiently to produce uniform and symmetric lesions of predictable and controllable depth. Microwave energy is generally safe when used near a catheter. In addition, microwaves do not rely on electrical conduction as they radiate through tissue, body fluids/blood, and air. Thus, microwave energy can be used in tissues, lumens, lungs and vessels.

In some embodiments, the power source is an energy generator. In some embodiments, the generator is configured to provide microwave energy at frequencies of as much as 100 watts from 915MHz to 2.45GHz, although the invention is not so limited. Solid state microwave generators in the 1-3GHz range are very expensive. Thus, in some embodiments, a conventional magnetron of the type commonly used in microwave ovens is selected as the generator. However, it will be appreciated that any other suitable source of microwave energy may be substituted. In some embodiments, the types of generators include, but are not limited to, generators available from Cober-Muegge, LLC, Norwalk, Connecticut, USA, Sairem generators, and Gerling Applied Engineering generators. In some embodiments, the generator has at least about 60 watts active power (e.g., 50, 55, 56, 57, 58, 59, 60, 61, 62, 65, 70, 100, 500, 1000 watts). For higher power operation, the generator can provide approximately 300 watts (e.g., 200 watts, 280, 290, 300, 310, 320, 350, 400, 750 watts). In some embodiments using multiple antennas, the generator can provide as much energy as is needed (e.g., 400 watts, 500, 750, 1000, 2000, 10000 watts).

In some embodiments, the power source distributes energy (e.g., energy harvested from the generator) via a power distribution system. The present invention is not limited to a particular power distribution system. In some embodiments, the power distribution system is configured to provide energy to an energy delivery device for tissue ablation (e.g., a tissue ablation catheter). The power distribution system is not limited to a particular manner of harvesting energy from the generator. The power distribution system is not limited to the particular manner in which energy is provided to the ablation device. In some embodiments, the power distribution system is configured to transform the characteristic impedance of the generator such that it matches the characteristic impedance of the energy delivery device (e.g., tissue ablation catheter).

In some embodiments, the power distribution system is configured with a variable power divider to provide varying energy levels to different regions of the energy delivery device, or to different energy delivery devices (e.g., tissue ablation catheters). In some embodiments, the power splitter is provided in the form of a separate component of the system. In some embodiments, a power splitter is used to supply separate energy signals to multiple energy delivery devices. In some embodiments, the power splitter isolates the energy delivered to each energy delivery device such that if one of the devices experiences an increase in load due to an increase in temperature deviation, the energy delivered to that device is changed (e.g., decreased, stopped) while the energy delivered to the spacing device is unchanged. The invention is not limited to a particular kind or type of power divider. In some embodiments, the power splitter is designed by SM Electronics. In some embodiments, the power splitter is configured to receive energy from the power generator and provide the energy to another system component (e.g., an energy transfer device). In some embodiments, the power splitter can be connected with one or more additional system components (e.g., 1,2, 3,4, 5,7, 10, 15, 20, 25, 50, 100, 500.). In some embodiments, the power divider is configured to deliver a variable amount of energy to different regions within the energy delivery device, such that a variable amount of energy is delivered from different regions of the energy delivery device. In some embodiments, a power splitter is used to provide a variable amount of energy to a plurality of energy delivery devices for treating a tissue region. In some embodiments, the power splitter is configured to operate within a system that includes a processor, an energy delivery device, a temperature adjustment system, a power splitter, a tuning system, and/or an imaging system. In some embodiments, the power splitter is capable of handling the maximum generator output plus, for example, 25% (e.g., 20%, 30%, 50%). In some embodiments, the power splitter is a 2-4 channel power splitter rated at 1000 watts.

In some embodiments, when multiple antennas are employed, the system of the present invention may be configured to operate the multiple antennas simultaneously or sequentially (e.g., via a switch). In some embodiments, the system is configured to adjust the phase of the field for constructive or destructive interference. Phase adjustment may also be applied to different elements within a single antenna.

Energy transmission device

Energy transmission devices of the present invention contemplate the use of any type of device (e.g., ablation devices, surgical devices, etc.) configured to transmit (e.g., emit) energy (see, e.g., U.S. patent nos. 7,101,369, 7,033,352, 6,893,436, 6,878,147, 6,823,218, 6,817,999, 6,635,055, 6,471,696, 6,383,182, 6,312,427, 6,287,302, 6,277,113, 6,251,128, 6,245,062, 6,026,331, 6,016,811, 5,800,494, 6,016,811, 5,539,346, 4,494,302, U.S. patent application serial No. 6,016,811, 699, 6,016,811, uk patent application nos. 6,016,811, european patent application nos. 6,016,811, and international patent application nos. WO 6,016,811/6,016,811, WO 95/04385; all of the above patents and patent applications are hereby incorporated by reference in their entirety). Such devices include any medical, veterinary and research application device configured for energy emission, as well as devices used in agricultural environments, manufacturing environments, mechanical environments, or any other application where energy is to be delivered.

In some embodiments, the system utilizes an energy transmission device having an antenna therein configured to emit energy (e.g., microwave energy, radio frequency energy, radiant energy). The system is not limited to a particular type or design of antenna (e.g., ablation device, surgical device, etc.). In some embodiments, the system utilizes an energy transmission device having a linear antenna (see, e.g., U.S. Pat. Nos. 6,878,147, 4,494,539, U.S. patent application Ser. Nos. 11/728,460, 11/728,457, 11/728,428, 10/961,994, 10/961,761; and International patent application No. WO 03/039385; both of which are incorporated herein by reference in their entirety). In some embodiments, the system utilizes an energy transmission device having a non-linear antenna (see, e.g., U.S. Pat. Nos. 6,251,128, 6,016,811 and 5,800,494, U.S. patent application Ser. No. 09/847,181, and International patent application No. WO 03/088858; all incorporated herein by reference in their entirety). In some embodiments, the antenna has a flared reflective component (see, e.g., U.S. Pat. Nos. 6,527,768, 6,287,302; both incorporated herein by reference in their entirety). In some embodiments, the antenna has a directional reflector (see, e.g., U.S. patent No. 6,312,427; incorporated herein by reference in its entirety). In some embodiments, the antenna has a fixation assembly therein to secure the energy transmission device within a particular tissue region (see, for example, U.S. Pat. Nos. 6,364,876 and 5,741,249; both of which are incorporated herein by reference in their entirety).

Generally, antennas configured to transmit energy include coaxial transmission lines. The apparatus is not limited to a particular configuration of coaxial transmission lines. Examples of coaxial transmission lines include, but are not limited to, those developed by Paternack, Micro-coax, and SRC Cables. In some embodiments, a coaxial transmission line has a center conductor, a dielectric element, and an outer conductor (e.g., outer shield). In some embodiments, the system utilizes an antenna having a flexible coaxial transmission line (e.g., for placement around a pulmonary vein or through a tubular structure) (see, e.g., U.S. Pat. Nos. 7,033,352, 6,893,436, 6,817,999, 6,251,128, 5,810,803, 5,800,494; all incorporated herein by reference in their entirety). In some embodiments, the system utilizes an antenna having a rigid coaxial transmission line (see, e.g., U.S. Pat. No. 6,878,147, U.S. patent application Ser. Nos. 10/961,994 and 10/961,761, and International patent application No. WO 03/039385; all of which are incorporated herein by reference in their entirety).

The present invention is not limited to a particular coaxial transmission line shape. Indeed, in some embodiments, the shape of the coaxial transmission line and/or the dielectric element is selected and/or adjustable to suit particular needs. Fig. 2 illustrates some of the various non-limiting shapes that a coaxial transmission line and/or dielectric element may take.

In some embodiments, the outer conductor is a 20 gauge needle or an assembly having a diameter similar to a 20 gauge needle. Preferably, the outer conductor is no larger than a 16 gauge needle (e.g., no larger than an 18 gauge needle) for percutaneous applications. In some embodiments, the outer conductor is a 17 gauge pin. However, in some embodiments, larger devices are used as appropriate. For example, in some embodiments, a 12 gauge diameter is used. The invention is not limited by the size of the outer conductor. In some embodiments, the outer conductor is configured to be secured within a series of larger needles in order to participate in a medical procedure (e.g., participate in a tissue biopsy) (see, e.g., U.S. patent nos. 6,652,520, 6,582,486, 6,355,033, 6,306,132; all of which are incorporated herein by reference in their entirety). In some embodiments, the center conductor is configured to extend beyond the outer conductor to deliver energy to a desired location. In some embodiments, a portion or all of the characteristic impedance of the feed line is optimized for minimal power dissipation, regardless of the type of antenna terminated at its distal end.

In some embodiments, the energy transmission device is provided with a proximal portion and a distal portion, wherein the distal portion is detachable and provided in a variety of different configurations that can be connected to the central proximal portion. For example, in some embodiments, the proximal portion includes a handle and interface to other components of the system (e.g., a power source), and the distal portion includes a detachable antenna having desired properties. A plurality of different antennas configured for different applications may be provided and attached to the handle unit for appropriate pointing.

In some embodiments, the device is configured to be attached with a detachable handle. The present invention is not limited to a particular type of detachable handle. In some embodiments, the detachable handle is configured to connect with multiple devices (e.g., 1,2, 3,4, 5, 10, 20, 50.) in order to control the transmission of energy through the devices.

In some embodiments, the device is designed to physically surround a particular tissue region in order to transmit energy (e.g., the device may be flexibly shaped around the particular tissue region). For example, in some embodiments, the device may be flexibly shaped around a blood vessel (e.g., a pulmonary vein) in order to deliver energy to an accurate region within the tissue.

In some embodiments, the energy transmission device is provided in the form of two or more separate antennas connected to the same or different power sources. In some embodiments, different antennas are attached to the same handle, while in other embodiments, different handles are provided for each antenna. In some embodiments, multiple antennas are used, either simultaneously or sequentially (e.g., switched) within the patient's body, to deliver energy of a desired intensity and geometry within the patient's body. In some embodiments, the antennas are individually controllable. In some embodiments, multiple antennas may be operated by a single user through a computer or by multiple users.

In some embodiments, the energy transfer device is designed to operate within a sterile zone. The present invention is not limited to a particular sterile field environment. In some embodiments, the sterile field includes an area surrounding the subject (e.g., an operating table). In some embodiments, the sterile zone includes any area that allows only the use of sterile items (e.g., sterile equipment, sterile aids, sterile body parts). In some embodiments, the sterile zone includes any area susceptible to infection by a pathogen. In some embodiments, the sterile zone has a sterile zone barrier therein that establishes a barrier between the sterile zone and the non-sterile zone. The present invention is not limited to a particular sterile field barrier. In some embodiments, the sterile zone barrier is a drape that surrounds a subject undergoing a procedure (e.g., tissue ablation) involving the system of the present invention. In some embodiments, the room is sterile and provides a sterile field. In some embodiments, the sterile zone barrier is established by a user (e.g., a physician) of the system of the present invention. In some embodiments, the sterile zone barrier prevents non-sterile items from entering the sterile zone. In some embodiments, the energy transfer device is disposed in the sterile zone, while one or more other components of the system (e.g., the power source) are not contained in the sterile zone.

In some embodiments, the energy transmission device has a protective sensor therein for preventing undesired use of the energy transmission device. The energy transmission device is not limited to a particular type or kind of protective sensor. In some embodiments, the energy transmission device has a temperature sensor therein for measuring the temperature of the energy transmission device and/or tissue in contact with the energy transmission device. In some embodiments, when the temperature reaches a certain level, the sensor alerts the user via, for example, the processor. In some embodiments, the energy transmission device has a skin contact sensor therein for detecting contact of the energy transmission device with the skin (e.g., the outer surface of the skin). In some embodiments, the skin contact sensor alerts the user via the processor when contact is made with non-desired skin. In some embodiments, the energy transmission device has an air contact sensor therein for detecting contact of the energy transmission device with ambient air (e.g., detection of reflected power by measuring current flowing through the device). In some embodiments, the skin contact sensor alerts the user via the processor when contact with non-desired air is made. In some embodiments, the sensor is used to prevent use of the energy transmission device (e.g., by automatically reducing or preventing power transmission) upon detection of an undesirable event (e.g., contact with skin, contact with air, undesired temperature increase/decrease). In some embodiments, the sensor is in communication with the processor such that the processor displays a notification (e.g., a green light) without an undesirable event. In some embodiments, the sensor is in communication with the processor such that in the event of an undesirable event, the processor displays a notification (e.g., a red light) and identifies the undesirable event.

In some embodiments, the energy delivery device is used above the manufacturer's recommended power rating. In some embodiments, the cooling techniques described herein are applied to allow for higher energy transfer. The present invention is not limited to a particular power increase. In some embodiments, the power rating exceeds 5 times or more of the manufacturer's recommended value (e.g., 5x, 6x, 10x, 15x, 20x, etc.).

In addition, the device of the present invention is configured to transfer energy from different regions of the device (e.g., outer conductor segment gaps, described in more detail below) at different times (e.g., user-controlled times) and at different energy densities (e.g., user-controlled energy densities). Such control of the apparatus allows for phase adjustment of the energy transmission field to achieve constructive phase interference in a particular tissue region or to achieve destructive phase interference in a particular tissue region. For example, a user may employ energy transmission through two (or more) closely placed outer conductor segments in order to achieve a combined energy intensity (e.g., constructive phase interference). Such combined energy intensities are particularly useful in deep or dense tissue regions. In addition, such a combined energy intensity may be achieved by utilizing two (or more) devices. In some embodiments, phase interference (e.g., constructive phase interference, destructive phase interference) between one or more devices is controlled by a processor, tuning element, user, and/or power splitter. Thus, the user is able to control the release of energy through different regions of the device and to control the amount of energy transmitted through each region of the device in order to accurately etch the ablation zone.

In some embodiments, the energy transfer system of the present invention utilizes an energy transfer device with optimized characteristic impedance, an energy transfer device with cooling channels, an energy transfer device with a center fed dipole, and an energy transfer device with a linear array of antenna elements (detailed above and below, respectively).

As described above in the summary, the present invention provides various methods of cooling a device. Some embodiments employ a meltable barrier that, when melted, allows contact of the chemical species that undergoes the endothermic reaction. An example of such an embodiment is shown in fig. 3. Fig. 3A and 3B show a region of a coaxial transmission line (e.g., a channel) having segmented sections, the first and second materials separated by a fusible wall to prevent unwanted device heating (e.g., along the outer conductor). Fig. 3A and 3B depict a standard coaxial transmission line 300 configured for use within any of the energy transmission devices of the present invention. As shown in fig. 3A, the coaxial transmission line 300 has a center conductor 310, a dielectric material 320, and an outer conductor 330. In addition, there are four segmented sections 340 in the coaxial transmission line 300 separated by walls 350 (e.g., fusible wax walls). The divided section 340 is divided into a first divided section 360 and a second divided section 370. In some embodiments, as shown in fig. 3A, the first and second segmented sections 360 and 370 are continuously interleaved. As shown in fig. 3A, the first segmented section 360 comprises a first material (shaded type 1) and the second segmented section 370 comprises a second material (shaded type 2). The wall 350 prevents the first and second materials from mixing. Fig. 3B shows the coaxial transmission line 300 depicted in fig. 3A after some event (e.g., a temperature rise at one of the segmented sections 340). As shown, one of the walls 350 has melted, allowing the first material contained in region 360 and the second material contained in region 370 to mix. Fig. 3B also shows an unmelted wall 350, wherein the temperature rise does not reach above a certain temperature threshold.

Fig. 4 shows an alternative embodiment. Fig. 4A and 4B show coaxial transmission line embodiments having segmented sections separated by fusible walls comprising first and second materials (e.g., materials configured to produce a temperature-reducing chemical reaction when mixed) that prevent unwanted device heating (e.g., heating along the outer conductor). Fig. 4A and 4B illustrate a coaxial transmission line 400 configured for use in any of the energy transmission devices of the present invention. As shown in fig. 4A, a coaxial transmission line 400 has a center conductor 410, a dielectric material 420, and an outer conductor 430. In addition, there are four segmented sections 440 in the coaxial transmission line 400 separated by walls 450. The walls 450 each comprise a first material 460 separated from a second material 470. Fig. 4B shows the coaxial transmission line 400 depicted in fig. 4A after some event (e.g., a temperature rise at one of the segmented sections 440). As shown, one of the walls 450 has melted, allowing for mixing of the first material 460 and the second material 470 within adjacent segmented sections 440. Fig. 4B also shows an unmelted wall 450, wherein the temperature has not risen above a certain temperature threshold.

In some embodiments, the device further includes an anchoring element to secure the antenna to the particular tissue region. The device is not limited to a particular kind of anchoring element. In some embodiments, the anchoring element is an inflatable balloon (e.g., inflation of the balloon secures the antenna to a particular tissue region). Another advantage of using an inflated balloon as an anchoring element is that blood or air flow to a specific area is inhibited when the balloon is inflated. Such airflow or blood flow suppression is particularly useful in cardiac ablation procedures and ablation procedures involving lung tissue, vascular tissue, and gastrointestinal tissue. In some embodiments, the anchoring element is an extension of the antenna that is designed to engage (e.g., grasp) a particular tissue region. Other examples include, but are not limited to, the anchoring elements described in U.S. Pat. nos. 6,364,876 and 5,741,249; all of the above U.S. patents are incorporated herein by reference in their entirety.

Thus, in some embodiments, the device of the present invention is used in the ablation of tissue regions having substantial airflow and/or blood flow (e.g., lung tissue, heart tissue, gastrointestinal tissue, vascular tissue). In some embodiments involving ablation of a tissue region having substantial airflow and/or blood flow, an element is also utilized to inhibit airflow and/or blood flow to the tissue region. The present invention is not limited to a particular airflow and/or blood flow suppression element. In some embodiments, the device is integrated with an endotracheal/endobronchial catheter. In some embodiments, a balloon attached to the device is inflated at the tissue region to secure the device within the desired tissue region and inhibit blood and/or air flow to the desired tissue region.

Thus, in some embodiments, the systems, devices, and methods of the present invention provide an ablation device coupled with an assembly that forms an occlusion of a passageway (e.g., a bronchial occlusion). The occlusion assembly (e.g., an inflatable balloon) may be mounted directly on the ablation system, or may be used in conjunction with another assembly associated with the system (e.g., an endotracheal or endobronchial catheter).

In some embodiments, the devices of the present invention may be mounted on additional medical procedure devices. For example, the device may be mounted on an endoscope, intravascular catheter, or laparoscope. In some embodiments, the device is mounted on a steerable catheter. In some embodiments, the flexible catheter is mounted on an endoscope, intravascular catheter, or laparoscope. For example, in some embodiments, the flexible catheter has multiple points of engagement (e.g., similar to centipedes) that allow bending and steering as needed to navigate to the desired treatment location.

Energy transmission device with optimized characteristic impedance

In some embodiments, the energy delivery system of the present invention utilizes a device configured to deliver microwave energy with optimized characteristic impedance (see, for example, U.S. patent application serial No.11/728,428; incorporated herein by reference in its entirety). Such devices are configured to operate with a characteristic impedance greater than 50 Ω (e.g., between 50 and 90 Ω; e.g., greater than 50, 55, 56, 57, 58, 59, 60, 61, 62,. 90 Ω, preferably 77 Ω).

Energy delivery devices configured to operate with optimized characteristic impedances are particularly useful in tissue ablation procedures, providing a number of advantages over non-optimized devices. For example, a major drawback of currently available medical devices utilizing microwave energy is that the energy is undesirably dissipated to the subject's tissue through the transmission line, resulting in an undesirable burn. This microwave energy loss arises from design limitations of currently available medical devices. The standard impedance of a coaxial transmission line within a medical device is 50 Ω or less. Generally, coaxial transmission lines with impedances below 50 Ω have a large amount of heat loss due to the presence of dielectric materials with finite conductivity values. Thus, a medical device having a coaxial transmission line with an impedance of 50 Ω or less has a large amount of heat loss along the transmission line. In particular, medical devices that utilize microwave energy transmit energy through a coaxial cable having a dielectric material (e.g., polytetrafluoroethylene or PTFE) therein surrounding an inner conductor. Dielectric materials such as PTFE have limited conductivity, resulting in undesirable heating of the transmission line. This is especially true when the necessary amount of energy is delivered for a sufficient amount of time to enable ablation of the tissue. Energy transfer devices configured to operate with optimized characteristic impedance overcome this limitation by being devoid, or substantially devoid, of solid dielectric insulators. For example, using air instead of a conventional dielectric insulator results in an efficient device operating at 77 Ω. In some embodiments, the apparatus employs a dielectric material (e.g., air, water, inert gas, vacuum, partial vacuum, or combinations thereof) having a conductivity near zero. By using a coaxial transmission line with a dielectric material having a conductivity close to zero, the overall temperature of the transmission line within such a device is significantly reduced, thereby greatly reducing unwanted tissue heating.

In addition, by providing a coaxial transmission line with a dielectric material having a conductivity close to zero and avoiding the use of typical dielectric polymers, the coaxial transmission line can be designed so as to be able to fit within a fine needle (e.g., 18-20 gauge needle). Generally, due to the bulky volume of dielectric materials, medical devices configured to transmit microwave energy are designed to fit within larger needles. Microwave ablation has not been widely used clinically due to the large probe size (number 14), and the small necrosis zone (1.6 mm diameter) created by the only commercial equipment (Microtaze, Nippon Shoji, Osaka, Japan, 2.450MHz, 1.6 mm diameter, 60 seconds 70 watts) (Seki T et al, Cancer 74: 817 (1994)). Other devices use external cooling water jackets, which also increase the size of the probe and can increase tissue damage. These larger probe sizes increase the risk of complications when used in the thoraco-abdominal region.

Energy transmission device with cooling channel

In some embodiments, the energy delivery system of the present invention utilizes an energy delivery device having cooling channels (see, e.g., U.S. patent No. 6,461,351 and U.S. patent application serial No.11/728,460; both incorporated herein by reference in their entirety). In particular, the energy transfer system of the present invention utilizes a device having a coaxial transmission line cooled by flowing a cooling material through the dielectric and/or inner or outer conductor of the coaxial assembly. In some embodiments, the device is configured to minimize the diameter of the device while allowing the passage of coolant. In some embodiments, this is accomplished by replacing the inner or outer conductor bars and/or the strips of solid dielectric material with channels through which coolant is transported. In some embodiments, the channel is created by stripping the outer or inner conductor and/or solid dielectric material from one or more (e.g., two, three, four) regions along the length of the coaxial cable. Because the removed portion of the outer or inner conductor and/or solid dielectric material creates a channel for the transport of coolant, the stripped assembly fits within a smaller outer conductor than before the outer or inner conductor and/or solid dielectric material was removed. This provides a smaller device with all the advantages resulting therefrom. In some embodiments employing multiple channels, coolant delivery may be in alternating directions through one or more channels. One advantage of such an apparatus is that the diameter of the coaxial cable does not have to be increased to accommodate the coolant. This allows the use of minimally invasive cooling devices and allows access to body parts that are otherwise inaccessible or where there is an undesirable risk of access. The use of a coolant also allows for the transfer of more energy and/or for extended energy transfer. Additional cooling embodiments are described above in the summary.

In some embodiments, the device has a handle attached to the device, wherein the handle is configured to control the passage of coolant into and out of the coolant channel. In some embodiments, the handle automatically causes coolant to enter and exit the cooling channel after a certain time and/or when the device reaches a certain threshold temperature. In some embodiments, the handle automatically stops coolant from entering or exiting the cooling channel after a certain time and/or when the temperature of the device falls below a certain threshold temperature. In some embodiments, the handle is manually controlled to regulate coolant flow.

FIG. 5 shows a schematic view of a handle configured to control the flow of coolant into and out of the cooling gallery. As shown in fig. 5, the handle 500 engages a coaxial transmission line 510 having a cooling channel 520. The handle 500 has a coolant inlet channel 530, a coolant outlet channel 540, a first blocking assembly 550 (e.g., a screw or pin) and a second blocking assembly 560 in it, the first blocking assembly 550 being configured to block flow through the channel 520 behind it. The coolant input channel 530 is configured to provide coolant to the cooling channel 520. The coolant output channel 540 is configured to remove coolant (e.g., coolant that has circulated and removed heat from the device) from the cooling channel 520. The coolant input channels 530 and the coolant output channels 540 are not limited to a particular size or means of providing and removing coolant. The first blocking assembly 550 and the second blocking assembly 560 are not limited to a particular size or shape. In some embodiments, both the first blocking assembly 550 and the second blocking assembly 560 are circular in shape and sized to match the diameters of the coolant input channel 530 and the coolant output channel 540. In some embodiments, the first blocking assembly 550 and the second blocking assembly 560 are used to prevent coolant from flowing back to a region of the handle 500. In some embodiments, the occlusion assembly is configured such that only a portion (e.g., 1%, 5%, 10%, 20%, 50%, 75%, 85%, 95%, 99%) of the channel is occluded. Blocking only a portion of the channel allows the user to vary the pressure gradient within the cooling channel 500.

The energy transfer device with the cooling channel facilitates adjusting the characteristic impedance of the coaxial transmission line. In particular, the dielectric properties of the coolant (or non-coolant material passing through the channels) may be adjusted to alter the volumetric complex dielectric constant of the dielectric medium separating the outer conductor and the inner conductor. Thus, a change in characteristic impedance is achieved during a medical procedure to optimize energy delivery, tissue effect, temperature, or other desired property of the system, device, or application. In other embodiments, the flowable material is selected prior to the medical procedure according to desired parameters and is maintained throughout the medical procedure. Such a device thus provides an antenna that radiates in a varying dielectric environment to be tuned, thereby resonating in a varying environment to allow adaptive tuning of the antenna, thereby ensuring peak efficiency of operation. The fluid flow also allows heat transfer to and from the coaxial cable, if desired. In some embodiments, the channel or hollow outer region comprises a vacuum or partial vacuum. In some embodiments, the impedance is varied by filling the vacuum with a material (e.g., any material that provides the desired result). The adjustment may be made at one or more times or continuously.

The energy transfer device with cooling channels is not limited to a particular aspect of the channels. In some embodiments, the channel is cut through only a portion of the outer or inner conductor and/or the solid dielectric material such that the flowing material is in contact with the inner or outer conductor and the remaining dielectric material. In some embodiments, the channel is linear along the length of the coaxial cable. In some embodiments, the channel is non-linear. In some embodiments where more than one channel is used, the channels run parallel to each other. In other embodiments, the channels are not parallel. In some embodiments, the channels intersect each other. In some embodiments, the channels remove more than 50% (e.g., 60%, 70%, 80%, etc.) of the outer or inner conductor and/or solid dielectric material. In some embodiments, the channel removes substantially all of the outer or inner conductor and/or solid dielectric material.

Energy transfer devices having cooling channels are not limited by the nature of the material flowing through the outer or inner conductor and/or the solid dielectric material. In some embodiments, the material is selected to maximize the ability to control the characteristic impedance of the device, to maximize heat transfer to and from the coaxial cable, or to optimize a combination of control of the characteristic impedance and heat transfer. In some embodiments, the material flowing through the outer or inner conductor and/or the solid dielectric material is a liquid. In some embodiments, the material is a gas. In some embodiments, the material is a combination of liquids or gases. The invention is not limited to the use of liquids or gases. In some embodiments, the material is a slurry, gel, or the like. In some embodiments, a coolant fluid is used. Any coolant fluid now known or later developed may be used. Exemplary coolant fluids include, but are not limited to, one or more or a combination of the following: water, glycols, air, inert gases, carbon dioxide, nitrogen, helium, sulfur hexafluoride, ionic solutions (e.g., sodium chloride with or without potassium and other ions), aqueous dextrose, ringer's lactate, organic chemical solutions (e.g., ethylene glycol, diethylene glycol, or propylene glycol), oils (e.g., mineral oil, silicone oil, fluorocarbon oil), liquid metals, freons, halomethanes, liquefied propane, other halogenated alkanes, anhydrous ammonia, sulfur dioxide. In some embodiments, the coolant fluid is pre-cooled before being input into the energy transmission device. In some embodiments, the coolant fluid is cooled with a cooling unit after entering the energy transfer device. In some embodiments, the material passing through the dielectric material is designed to produce an endothermic reaction when in contact with another material.

An energy transmission device having a cooling channel is configured to allow control of parameters of fluid infusion through the device. In some embodiments, the device is manually adjusted by a user (e.g., a treating physician or technician) as appropriate. In some embodiments, the adjustment is automatic. In some embodiments, the device is equipped with or used with sensors that provide information to a user or automated system (e.g., the system includes a processor and/or software that receives the information and adjusts fluid infusion or other device parameters accordingly). Adjustable parameters include, but are not limited to, infusion rate of the fluid, concentration of ions or other components affecting fluid properties (e.g., dielectric, thermal conductivity, flow rate, etc.), temperature of the fluid, type of fluid, mixing ratio (e.g., gas/liquid mixture for fine tuning or cooling). Thus, energy transmission devices with cooling channels are configured to more accurately adjust the device (e.g., antenna) or expedite infusion of fluid using a feedback loop capable of changing one or more desired parameters if the device, various parts of the device, or the subject's tissue reaches an undesirable temperature (or a temperature persists for an undesirable period of time).

Energy transfer devices having cooling channels have many advantages over currently available systems and devices. For example, the coaxial transmission line may be designed to fit within very small needles (e.g., 18-20 gauge or smaller) by providing the coaxial transmission line with a channel that is excavated and capable of substantially removing a substantial amount of solid dielectric material. Generally, due to the large volume of dielectric materials, medical devices configured to transmit microwave energy are designed to fit within a large needle. Other devices use external cooling water jackets that also increase probe size and can increase tissue damage. These larger probe sizes increase the risk of complications when used in the thoraco-abdominal region. In some embodiments of the invention, the portion of the device that enters the subject has a maximum outer diameter of 16-18 gauge or less (20 gauge or less).

Fig. 6 shows a schematic cross-sectional view of a standard coaxial cable embodiment and an embodiment of the present invention having cooling channels. As shown in fig. 6, a conventional coaxial cable 600 and two exemplary coaxial cables 610 and 620 of the present invention are provided. Coaxial cables are generally made up of three separate spaces: a metal inner conductor 630, a metal outer conductor 650, and a space therebetween. The space between the metallic inner conductor 630 and the metallic outer conductor 650 is typically filled with a low-loss dielectric material 640 (e.g., polytetrafluoroethylene or PTFE) to mechanically support the inner conductor and retain the low-loss dielectric material 640 with the outer conductor. The characteristic resistance of the coaxial cable is determined by the ratio of the diameter of the inner conductor and the diameter of the dielectric material (i.e., the inner diameter of the outer conductor), and the dielectric constant of the space between the metallic inner conductor 630 and the metallic outer conductor 650. Generally, the dielectric constant is fixed due to the solid polymer constituting the space. However, in embodiments of the invention, the fluid having a variable dielectric constant (or conductivity) at least partially occupies the space, thereby allowing the characteristic resistance of the cable to be adjusted.

Still referring to fig. 6, in one embodiment of the present invention, the coaxial cable 610 has the outer portion of the dielectric material removed, thereby creating a channel between the dielectric material 640 and the outer conductor 650. In the embodiment shown, the space created is divided into four distinct channels 670 by the addition of support lines 660 configured to maintain the space between the outer conductor 650 and the solid dielectric material 640. The support line 660 can be made of any desired material and can be the same or different material as the solid dielectric material 640. In some embodiments, to avoid undesirable heating of the device (e.g., undesirable heating of the outer conductor), the support wire 660 is made of a biocompatible, meltable material (e.g., wax). The presence of multiple channels allows one or more channels to allow flow in one direction (toward the proximal end of the cable) and one or more other channels to allow flow in the opposite direction (toward the distal end of the cable).

Still referring to fig. 6, in another embodiment, the coaxial cable 620 has a substantial portion of the solid dielectric material 640 removed. Such an embodiment may be produced by stripping the solid dielectric material 640 down to the surface of the inner conductor 630 on each of the four sides. In another embodiment, a lift-off of the dielectric material 640 is applied to the inner conductor 630 to create the structure. In this embodiment, four channels 670 are created. By removing a substantial amount of the dielectric material 640, the diameter of the outer conductor 650 is significantly reduced. The corners formed by the remaining dielectric material 640 provide support to maintain the position of the outer conductor 650 relative to the inner conductor 630. In this embodiment, the overall diameter of the coaxial cable 620 and the device is significantly reduced.

In some embodiments, the device has cooling channels formed by inserting tubes configured to circulate a coolant in the dielectric portion or inner or outer conductor of any of the energy emitting devices of the present invention. Fig. 7 shows a coolant circulation tube 700 (e.g., coolant needle, catheter) disposed within an energy emitting device 710 having an outer conductor 720, a dielectric material 730, and an inner conductor 740. As shown in fig. 7, tube 700 is disposed along an outer edge of dielectric material 730 and an inner edge of outer conductor 720, with inner conductor 740 disposed approximately in the center of dielectric material 730. In some embodiments, the tube 700 is disposed within the dielectric material 730 so as not to contact the outer conductor 720. In some embodiments, the tube 700 has a plurality of channels (not shown) to recirculate the coolant within the tube 700 without the coolant entering the dielectric material 730 and/or the outer conductor 720, thereby cooling the dielectric material 730 and/or the outer conductor 720 with the exterior of the tube 700.

Energy transfer device with center-fed dipole

In some embodiments, the energy delivery device of the present invention utilizes an energy delivery device that employs a center-fed dipole assembly (see, e.g., U.S. patent application serial No.11/728,457; incorporated herein by reference in its entirety). The device is not limited to a particular configuration. In some embodiments, the device has a center-fed dipole therein that heats the tissue region through the application of energy (e.g., microwave energy). In some embodiments, such devices have a coaxial cable connected to a hollow tube (e.g., having an inner diameter of at least 50% of the outer diameter; e.g., having an inner diameter substantially similar to the outer diameter). The coaxial cable may be a standard coaxial cable or may be a coaxial cable having a dielectric component therein (e.g., air) with a conductivity near zero. The hollow tube is not limited to a particular design configuration. In some embodiments, the hollow tube takes the shape of (a diameter of) a 20-gauge needle, for example. Preferably, the hollow tube is made of a solid, rigid, conductive material (e.g., a number of metals, conductor-coated ceramics or polymers, etc.). In some embodiments, the hollow tube is fitted with a tip, or a stylet is added to its distal end, to insert the device directly into the tissue region without the use of a cannula. The hollow tube is not limited to a particular composition (e.g., metal, plastic, ceramic). In some embodiments, the hollow tube comprises copper or a copper alloy with other hardening metals, silver or a silver alloy with other hardening metals, gold-plated copper, metalized Macor (machinable ceramic), metalized hardening polymer, and/or combinations thereof.

In some embodiments, the center-fed dipole is configured to adjust energy transfer characteristics in response to heating to provide more optimal energy transfer throughout the process. In some embodiments, this is achieved by using a material that changes volume in response to a change in temperature, such that the change in volume of the material changes the energy transfer characteristics of the device. In some embodiments, an expandable material is placed in the device such that, in response to heating, the resonating portion of the center-fed dipole assembly or the probe is pushed distally along the device. This changes the tuning of the device to maintain a more optimal energy transfer. The maximum amount of movement can be limited, if desired, by providing a locking mechanism that prevents extension beyond a certain point.

The energy transmission device using the center-fed dipole assembly is not limited by the connection manner of the hollow tube and the coaxial cable. In some embodiments, a portion of the outer conductor at the distal end of the coaxial cable feed is removed, exposing an area of the solid dielectric material. The hollow tube may be placed over the exposed dielectric material and attached to the exposed dielectric material by any means. In some embodiments, a physical gap is formed between the outer conductor and the hollow tube. In some embodiments, the hollow tube is capacitively or conductively connected to the feeder at its center point such that when inserted into tissue, the electrical length of the hollow tube constitutes a frequency resonant structure.

In use, an energy transmission device employing a center-fed dipole assembly is configured such that an electric field maximum is generated at the open distal end of the hollow tube. In some embodiments, the distal end of the hollow tube has a pointed shape to facilitate insertion of the device into the body of the subject and into the tissue region. In some embodiments, the entire device is rigid to facilitate straight line and direct insertion directly to the target site. In some embodiments, the structure resonates at 2.45GHz, characterized by a minimum in reflection coefficient (measured at the proximal end of the feed line) at that frequency. By varying the dimensions of the device (e.g., length, feed point, diameter, gap, etc.) and the material of the antenna (dielectric material, conductor, etc.), the resonant frequency can be varied. A low reflection coefficient at the desired frequency ensures an efficient energy transfer from the antenna to the medium surrounding the antenna.

Preferably, the hollow tube has a length of λ/2, where λ is the wavelength of the electromagnetic field in the medium of interest (e.g., -18 cm for 2.45GHz in the liver), so as to resonate within the medium. In some embodiments, the length of the hollow tube is approximately λ/2, where λ is the electromagnetic field wavelength in the medium of interest, so as to resonate within the medium, such that a minimum of power reflection at the proximal end is measured. However, lengths that deviate from this length may be used to create a resonant wavelength (e.g., when the surrounding material is altered). Preferably, the inner conductor of the coaxial cable is extended with its distal end at the centre of the tube (e.g. at λ/4 from the end of the tube) and is configured such that it remains in electrical contact at the centre of the tube, although it is allowed to deviate from this position (e.g. to produce a resonant wavelength).

The hollow tube part of the present invention may have various shapes. In some embodiments, the tube is cylindrical throughout its length. In some embodiments, the tube is tapered from a central location such that it has a smaller diameter at its ends than at its center. Having a smaller tip at the distal end facilitates penetration of the subject to reach the target area. In some embodiments where the shape of the hollow tube deviates from cylindrical, the tube maintains a symmetrical configuration on either side of its longitudinal center. However, the apparatus is not limited by the shape of the hollow tube, as long as functionality (i.e., the ability to deliver the desired energy to the target area) is achieved.

In some embodiments, a center-fed dipole assembly may be added to the distal end of various ablation devices to provide the advantages described herein. Likewise, various devices may be modified to accept the center-fed dipole assembly of the present invention.

In some embodiments, the device has a smaller outer diameter. In some embodiments, the center-fed dipole assembly of the present invention is used directly to insert the invasive components of the apparatus into the subject. In some such embodiments, the apparatus does not include a cannula, so that the invasive assembly may have a smaller outer diameter. For example, the invasive assembly may be designed such that it fits within a very small needle (e.g., 18-20 gauge or smaller) or is the same size as the very small needle described above.

Fig. 8 schematically illustrates a distal end of a device 800 of the present invention (e.g., an antenna of an ablation device) that includes a center-fed dipole assembly 810 of the present invention. Those skilled in the art will appreciate various alternative configurations for implementing the physical and/or functional characteristics of the present invention. As shown, the center-fed dipole device 800 has a hollow tube 815, a coaxial transmission line 820 (e.g., a coaxial cable), and a probe 890 therein. The center-fed dipole device 800 is not limited to a particular size. In some embodiments, the center-fed dipole device 800 is small enough in size to be placed on a tissue region (e.g., a liver) in order to deliver energy (e.g., microwave energy) to the tissue region.

Referring back to fig. 8, the hollow tube 815 is not limited to a particular material (e.g., plastic, ceramic, metal, etc.). The hollow tube 815 is not limited to a particular length. In some embodiments, the hollow tube has a length of λ/2, where λ is the electromagnetic field wavelength in the medium of interest (e.g., -18 cm for 2.45GHz in the liver). The hollow tube 815 engages the coaxial transmission line 820 such that the hollow tube 815 is attached to the coaxial transmission line 820 (described in more detail below). Hollow tube 815 has a hollow tube substance 860 therein. The hollow tube 815 is not limited to a particular type of hollow tube material. In some embodiments, the hollow tube substance 860 is air, fluid, or gas.

Still referring to fig. 8, the hollow tube 815 is not limited to a particular shape (e.g., cylindrical, triangular, square, rectangular, etc.). In some embodiments, hollow tube 815 is in the shape of a needle (e.g., 20 gauge needle, 18 gauge needle). In some embodiments, hollow tube 815 is divided into two portions, each of which may vary in length. As shown, hollow tube 815 is divided into two sections of equal length (e.g., each section having a length of λ/4). In such an embodiment, the shape of each portion is symmetrical. In some embodiments, the hollow tube has a diameter equal to or less than a 20 gauge needle, a 17 gauge needle, a 12 gauge needle, or the like.

Still referring to fig. 8, the distal end of hollow tube 815 engages probe 890. The apparatus 800 is not limited to a particular probe 890. In some embodiments, probe 890 is designed to facilitate percutaneous insertion of device 800. In some embodiments, stylet 890 is engaged with hollow tube 815 by sliding within hollow tube 815 such that stylet 890 is secured.

Still referring to fig. 8, the coaxial transmission line 820 is not limited to a particular type of material. In some embodiments, the proximal coaxial transmission line 820 is constructed from a commercial standard 0.047 inch semi-rigid coaxial cable. In some embodiments, the coaxial transmission line 820 is plated with metal (e.g., silver plating, copper plating), although the invention is not so limited. The proximal coaxial transmission line 820 is not limited to a particular length.

Still referring to fig. 8, in some embodiments, the coaxial transmission line 820 has a coaxial center conductor 830, a coaxial dielectric material 840, and a coaxial outer conductor 850. In some embodiments, coaxial center conductor 830 is configured to conduct a cooling fluid along its length. In some embodiments, coaxial center conductor 830 is hollow. In some embodiments, coaxial center conductor 830 has a diameter of 0.012 inches. In some embodiments, the coaxial dielectric material 840 is Polytetrafluoroethylene (PTFE). In some embodiments, the coaxial dielectric material 840 has near zero conductivity (e.g., air, fluid, gas).

Still referring to fig. 8, the distal end of coaxial transmission line 820 is configured to engage the proximal end of hollow tube 815. In some embodiments, coaxial center conductor 830 and coaxial dielectric material 840 extend to the center of hollow tube 815. In some embodiments, coaxial center conductor 830 extends further into hollow tube 815 than coaxial dielectric material 840. Coaxial center conductor 820 is not limited to a particular amount of extension into hollow tube 815. In some embodiments, coaxial center conductor 820 extends into hollow tube 815 a length of λ/4. The distal end of coaxial transmission line 820 is not limited to the particular manner of engaging the proximal end of hollow tube 815. In some embodiments, the proximal end of the hollow tube engages the coaxial dielectric material 840 to secure the hollow tube 815 with the coaxial transmission line 820. In some embodiments where the coaxial dielectric material has near zero conductivity, the hollow tube 815 is not fixed with a coaxial transmission line 820. In some embodiments, the distal end of coaxial center conductor 830 engages the wall of hollow tube 815 directly or by contact with conductive material 870, which may be composed of the same material as the coaxial center conductor or a different material (e.g., a different conductive material).

Still referring to fig. 8, in some embodiments, a gap 880 exists between the distal end of the coaxial transmission line outer conductor 850 and the hollow tube 815, thereby exposing the coaxial dielectric material 840. The gap 880 is not limited to a particular size or length. In some embodiments, the gap 880 assures a maximum electric field at the proximal end of the coaxial transmission line 880 and the distal open end of the hollow tube 815. In some embodiments, center-fed dipole device 810 resonates at 2.45GHz, as characterized by a minimum in reflection coefficient at that frequency. By varying the dimensions (length, feed point, diameter, gap, etc.) and materials (dielectric, conductor, etc.) of the device, the resonant frequency can be varied. The low reflection coefficient at this frequency ensures an efficient energy transfer from the antenna to the medium surrounding the antenna.

Still referring to fig. 8, in some embodiments, the gap 880 is filled with a material (e.g., epoxy) to bridge the coaxial transmission line 820 and the hollow tube 815. The apparatus is not limited to a particular type or kind of substantive material. In some embodiments, the substantial material does not interfere with the generation or emission of an energy field through the device. In some embodiments, the material is biocompatible and heat resistant. In some embodiments, the material is not or substantially not conductive. In some embodiments, the material also bridges the coaxial transmission line 820 and the hollow tube 815 with the coaxial center conductor 830. In some embodiments, the durable material is a curable resin. In some embodiments, the material is dental porcelain (e.g., XRV Herculite enamel; see also U.S. Pat. Nos. 6,924,325, 6,890,968, 6,837,712, 6,709,271, 6,593,395, and 6,395,803, all incorporated herein by reference in their entirety). In some embodiments, the durable material is cured (e.g., with a photo-curing machine, such as an l.e. demetron II photo-curing machine) (see, e.g., U.S. patent nos. 6,994,546, 6,702,576, 6,602,074, and 6,435,872). Thus, the present invention provides an ablation device comprising a cured enamel resin. Such resins are biocompatible and hard and strong.

Energy transfer device with linear array of antenna assemblies

In some embodiments, the energy transfer system of the present invention utilizes an energy transfer device having a linear array of antenna elements (see, e.g., U.S. provisional patent application No. 60/831,055; incorporated herein by reference in its entirety). The device is not limited to a particular configuration. In some embodiments, an energy transfer device having a linear array of antenna assemblies has an antenna therein comprising an inner conductor and an outer conductor, wherein the outer conductor is provided in the form of two or more linear segments separated by a gap such that the length and position of the segments are configured to optimize energy transfer at the distal end of the antenna. For example, in some embodiments, the antenna includes a first section of the outer conductor spanning from the proximal end of the antenna to a region proximate the distal end and a second section of the outer conductor distal of the first section, wherein the gap separates or partially separates the first and second sections. The gap may completely circumscribe the outer conductor or may only partially circumscribe the outer conductor. In some embodiments, the length of the second segment is λ/2, λ/4, etc., although the invention is not limited thereto. In some embodiments, one or more additional (e.g., third, fourth, fifth) segments, each separated from each other by a gap, are disposed at a distal end of the second segment. In some embodiments, the antenna terminates a conductive terminal end in electrical communication with the inner conductor. In some embodiments, the conductor terminal end comprises a circular disk having a diameter substantially equal to the diameter of the outer conductor. Such an antenna provides multiple peaks of energy transmission along the length of the distal end of the antenna, thereby providing a wider range of energy transmission to a larger target area of tissue. The location and state of the peak is controlled by selecting the length of the outer conductor section and controlling the amount of energy transferred.

An energy transmission device having a linear array of antenna components is not limited by the nature of the individual components of the antenna. Various components may be used to provide optimal performance including, but not limited to, the use of various materials for the inner and outer conductors, the use and configuration of various materials for the dielectric material between the inner and outer conductors, and the use of coolants provided by various different methods.

In some embodiments, the apparatus includes a linear antenna, wherein the linear antenna includes an outer conductor surrounding an inner conductor, wherein the inner conductor is designed to receive and transmit energy (e.g., microwave energy), wherein the outer conductor has a series of interstitial regions (e.g., at least two) therein arranged along the outer conductor, wherein the inner conductor is exposed at the interstitial regions, wherein energy transmitted along the inner conductor is emitted through the interstitial regions. The device is not limited to a particular number of interstitial regions (e.g., 2,3, 4,5, 6, 10, 20, 50). In some embodiments, the positioning of the gap is configured to achieve linear ablation. In some embodiments, the inner conductor comprises a dielectric layer surrounding the central transmission line. In some embodiments, the dielectric element has a conductivity close to zero. In some embodiments, the apparatus further comprises a probe. In some embodiments, the apparatus further comprises a regulating element that regulates the amount of energy transmitted through the clearance zone. In some embodiments, when used in a tissue ablation environment, the device is configured to deliver a sufficient amount of energy to ablate a tissue region or cause thrombus formation.

Energy transfer devices having linear arrays of antenna assemblies offer a number of advantages over currently available systems and devices. For example, one major drawback of currently available medical devices utilizing microwave energy is that the emitted energy is provided locally, thereby impeding energy transmission on deeper and denser scales. The apparatus of the present invention overcomes this limitation by providing an applicator device having a linear array of antenna elements which transmit energy (e.g. microwave energy) over a wider and deeper scale (e.g. as opposed to localized transmission). Such devices are particularly useful in dense and/or thick tissue regions (e.g., tumors, organ lumens), particularly in deep tissue regions (e.g., large heart regions, brain, bone).

III. processor

In some embodiments, the energy delivery devices of the present invention utilize a processor that monitors and/or controls one or more components of the system. In some embodiments, the processor is disposed within the computer module. The computer module may also contain software for implementing one or more of its functions by the processor. For example, in some embodiments, the systems of the present invention provide software that adjusts the amount of microwave energy provided to a tissue region by monitoring one or more characteristics of the tissue region, including (but not limited to) the size and shape of the target tissue, the temperature of the tissue region, and the like (e.g., via a feedback system) (see, e.g., U.S. patent application Ser. Nos. 11/728.460, 11/728,457, and 11/728,428; all of which are incorporated herein by reference in their entirety). In some embodiments, the software is configured to provide information (e.g., monitoring information) in real-time. In some embodiments, the software is configured to interact with the energy delivery system of the present invention such that the amount of energy delivered to the tissue region can be increased or decreased (e.g., adjusted). In some embodiments, software is used to infuse the energy transmission device with coolant for dispensing such that the coolant is at a desired temperature prior to use of the energy transmission device. In some embodiments, the type of tissue being treated (e.g., liver) is entered into software to allow the processor to adjust (e.g., tune) the transmission of microwave energy to the tissue region according to a method that is pre-calibrated for that particular type of tissue region. In other embodiments, the processor generates a chart or illustration showing characteristics useful to a user of the system based on a particular type of tissue region. In some embodiments, the processor provides an energy delivery algorithm to slowly increase the power to avoid tissue disruption due to rapid outgassing caused by high temperatures. In some embodiments, the processor allows the user to select power, duration of treatment, different treatment algorithms for different tissue types, apply power to the antennas simultaneously in a multiple antenna mode, switch power transmission between antennas, coherent and non-coherent phase adjustments, and so forth. In some embodiments, the processor is configured to create a database of information related to ablation therapy with respect to a particular tissue region (e.g., required energy level, treatment time for a tissue region based on a particular patient characteristic) from prior treatments having similar or dissimilar patient characteristics.

In some embodiments, the processor is used to generate an ablation map based on input of tissue characteristics (e.g., tumor type, tumor size, tumor location, peripheral vascular information, blood flow information, etc.). In such embodiments, the processor can direct placement of the energy delivery device to achieve the desired ablation according to the ablation profile.

In some embodiments, a software package is provided to interact with a processor that allows a user to input parameters of the tissue to be treated (e.g., the type, size, location of the tumor and tissue portion to be ablated, the location of the catheter or vulnerable tissue, and blood flow information), and then to map a desired ablation zone on a CT or other image to provide a desired result. The probe may be placed in tissue and the computer generates the desired ablation zone based on the information provided. Such an application may incorporate feedback. For example, during ablation, CT, MRI, or ultrasound imaging or thermometry may be used. The data is fed back into the computer and the parameters are readjusted to produce the desired result.

The terms "computer memory" and "computer storage device" as used herein refer to any storage medium readable by a computer processor. Examples of computer memory include, but are not limited to, Random Access Memory (RAM), Read Only Memory (ROM), computer chips, optical disks (e.g., Compact Disks (CDs), digital video disks), etc.), magnetic disks (e.g., Hard Disk Drives (HDDs), floppy disks, zip. rtm. disks, etc.), magnetic tape, and solid state memory devices (e.g., memory cards, "flash" media, etc.).

The term "computer-readable medium" as used herein refers to any device or system that stores and provides information (e.g., data and instructions) to a computer processor. Examples of computer readable media include, but are not limited to, optical disks, magnetic tape, solid state media, and servers streaming media over a network.

The terms "processor" and "central processor" are used interchangeably herein to refer to a device capable of reading a program from a computer storage device (e.g., ROM or other computer memory) and performing a set of steps in accordance with the program.

Imaging system

In some embodiments, the energy delivery system of the present invention utilizes an imaging system that includes an imaging device. The energy delivery system is not limited to a particular type of imaging device (e.g., endoscopic devices, stereotactic computer-assisted neurosurgical navigation devices, thermal sensor positioning systems, motion rate sensors, guidewire systems, intraoperative ultrasound, fluoroscopy, computerized tomography magnetic resonance imaging, nuclear medicine imaging device triangulation, thermoacoustic imaging, infrared and/or laser imaging, electromagnetic imaging) (see, e.g., U.S. patent nos. 6,817,976, 6,577,903 and 5,697,949, 5,603,697, and international patent application No. WO06/005,579; all of which are incorporated herein by reference in their entirety). In some embodiments, the system utilizes an endoscopic camera, an imaging assembly, and/or a navigation system that allows or facilitates placement, positioning, and/or monitoring of any item used with the energy system of the present invention.

In some embodiments, the energy delivery system provides software configured for use with an imaging device (e.g., CT, MRI, ultrasound). In some embodiments, the imaging device software allows the user to make predictions based on known thermodynamic and electrical properties of the tissue, vasculature, and antenna location. In some embodiments, the imaging software allows for the generation of a three-dimensional map of the location of a tissue region (e.g., tumor, arrhythmia), the location of the antenna, and the generation of a predicted map of the ablation zone.

In some embodiments, the imaging system of the present invention is used to monitor an ablation procedure (e.g., a microwave thermal ablation procedure, a radiofrequency thermal ablation procedure). The invention is not limited to a particular type of monitoring. In some embodiments, an imaging system is used to monitor the amount of ablation that occurs within a particular tissue region undergoing a thermal ablation process. In some embodiments, monitoring is performed along an ablation device (e.g., energy delivery device) such that the amount of energy delivered to a particular tissue region is dependent on the imaging of the tissue region. The invention is not limited to a particular type of monitoring. The present invention is not limited to content monitored with an imaging device. In some embodiments, the monitoring is imaging of blood perfusion in a particular region to detect changes in the region before, during, and after a thermal ablation procedure. In some embodiments, monitoring includes (but is not limited to) MRI imaging, CT imaging, ultrasound imaging, nuclear medicine imaging, and fluoroscopy imaging. For example, in some embodiments, a subject (e.g., a patient) is administered a contrast agent (e.g., iodine or other suitable CT contrast agent; gadolinium chelates or other suitable MRI contrast agents, microbubbles or other suitable ultrasound contrast agents, etc.) prior to a thermal ablation procedure, and the contrast agent perfused through a particular tissue region undergoing the ablation procedure is monitored for changes in blood flow perfusion.

In some embodiments, the imaging system is designed to automatically monitor a particular tissue region at any desired frequency (e.g., every second, every minute, every 10 minutes, every hour, etc.). In some embodiments, the present invention provides software for automatically obtaining an image of a tissue region (e.g., MRI imaging, CT imaging, ultrasound imaging, nuclear medicine imaging, fluoroscopy imaging), automatically detecting any change in the tissue region (e.g., blood perfusion, temperature, amount of necrotic tissue, etc.), and automatically adjusting the amount of energy delivered to the tissue region by an energy delivery device based on the detection. Likewise, an algorithm can be applied to predict the shape and size of a region of tissue to be ablated (e.g., tumor shape) so that the system recommends the type, number, and location of ablation probes that are effective to treat the region. In some embodiments, the system is configured with a navigation or guidance system (e.g., employing triangulation or other positioning routines) to assist or guide the placement of the probe and its use.

For example, such a procedure may use an increase or decrease in the contrast material bolus to track the progress of the ablation or other therapeutic procedure. A subtractive method (similar to the method used for digital subtraction angiography) may also be used. For example, a first image may be obtained at a first time, with subsequent images subtracting some or all of the information derived from the first image, making it easier to observe changes in tissue. Likewise, accelerated imaging techniques that apply "undersampling" techniques (as opposed to Nyquist sampling) may be used. It is expected that this technique provides excellent signal-to-noise ratio by utilizing multiple low resolution images obtained over time. For example, an algorithm known as HYPER (high constrained projection reconstruction) may be used for MRI applicable to embodiments of the system of the present invention.

Since heat-based treatments coagulate blood vessels when tissue temperatures exceed, for example, 50 ℃, the coagulation reduces blood supply to the area that has been completely coagulated. After administration of the contrast agent, the coagulated tissue region is not enhanced. In some embodiments, the present invention automatically tracks the progress of the ablation procedure with an imaging system by administering a small test injection of contrast agent to determine the time for the contrast agent to reach the tissue region of interest and determine the baseline enhancement. In some embodiments, after the ablation process is initiated, a series of small injections of contrast agent are then performed (e.g., in the case of CT, a series of 10ml bolus injections of up to 15 injections of 300mgI/ml of water-soluble contrast agent), a scan is performed at the desired appropriate post-injection time (e.g., determined from the test injection), and contrast enhancement of the target region is determined by tracking any one of a number of parameters using the region of interest (ROI), including, but not limited to, attenuation of CT (Hounsfield units (HU)), signal (MRI), echo (ultrasound), etc. The imaging data is not limited to a particular presentation. In some embodiments, the imaging data is presented as a color-coded or gray-scale or overlay of attenuation/signal/echo, difference between target and non-target tissues, difference in arrival time of contrast bolus during treatment, change in tissue perfusion, and change in any other tissue property that can be measured before and after injection of contrast material. The method of the present invention is not limited to a selected ROI, but can be generalized to all pixels within any image. The pixels may be color coded or an overlay indicating where tissue changes have occurred and are occurring. As the tissue properties change, the pixels may change color (or other properties) giving a near real-time indication of the progress of the treatment. This method can also be generalized to the 3d/4d method of image display.

In some embodiments, the area to be treated is presented on a computer overlay, and a second overlay of a different color or shade produces a near real-time display of the progress of the treatment. In some embodiments, the presentation and imaging is automated such that there is a feedback loop of treatment technology (RF, MW, HIFU, laser, ice, etc.) to adjust the power (or any other control parameter) according to the imaging results. For example, if the perfusion of the target area falls to a target level, the power may be reduced or stopped. For example, such embodiments are suitable for multi-applicator systems because the power/time/frequency/duty cycle is adjusted for individual applicators or elements in a phased array system to produce accurate ablation zones for tissue treatment. Rather, in some embodiments, these methods are used to select areas that will not be treated (e.g., vulnerable tissue, such as bile ducts, bowel, etc., that need to be avoided). In such embodiments, the method monitors tissue changes in the area to be avoided and alerts a user (e.g., a treating physician) of the risk of damage to the tissue to be protected using an alert (e.g., a visual and/or audible alert). In some embodiments, a feedback loop is used to modify the power or any other parameter to avoid continuing to damage selected untreated tissue regions. In some embodiments, protecting a tissue region from ablation is achieved by setting a threshold, such as a target ROI in the vulnerable region, or using a computer overlay to define a "no treatment" region desired by the user.

V. tuning system

In some embodiments, the energy delivery device of the present invention utilizes a tuning element to adjust the amount of energy delivered to a tissue region. In some embodiments, the tuning elements are manually adjusted by a system user. In some embodiments, a tuning system is incorporated into the energy transmission device to allow a user to adjust the energy transmission of the device as appropriate (see, e.g., U.S. Pat. Nos. 5,957,969, 5,405,346; all of which are incorporated herein by reference in their entirety). In some embodiments, the device is pre-tuned with respect to the desired tissue and is fixed throughout the treatment. In some embodiments, the tuning system is designed to match the impedance between the generator and the energy delivery device (see, e.g., U.S. patent No. 5,364,392; incorporated herein by reference in its entirety). In some embodiments, the tuning elements are automatically adjusted and controlled by the processor of the present invention (see, e.g., U.S. patent No. 5,693,082; incorporated herein by reference in its entirety). In some embodiments, the processor adjusts the energy delivery over time to provide constant energy throughout the procedure, taking into account a number of desired factors, including (but not limited to) the heating, nature, and/or location of the target tissue, the desired lesion size, the length of treatment time, proximity to sensitive organ areas or blood vessels, and the like. In some embodiments, the system includes sensors that provide feedback to the user or to a processor monitoring the functionality of the device, either continuously or at multiple points in time. The sensor may record and/or report a number of properties including, but not limited to, heating at one or more locations of a component of the system, heating at tissue, a property of the tissue, and the like. The sensor may take the form of an imaging device such as CT, ultrasound, magnetic resonance imaging or any other imaging device. In some embodiments, particularly for research applications, the system records and stores information for use in future optimization systems, and/or optimization of energy delivery under specific conditions (e.g., patient type, tissue type, size and shape of target region, location of target region, etc.).

VI temperature adjusting system

In some embodiments, the energy delivery system of the present invention utilizes a cooling system to reduce undesirable heating within and along the energy delivery device (e.g., a tissue ablation catheter). The system of the present invention is not limited to a particular cooling system mechanism. In some embodiments, the system is designed to circulate a coolant (e.g., air, liquid, etc.) throughout the energy transmission device such that the coaxial transmission line and antenna temperatures are reduced. In some embodiments, the system utilizes an energy transfer device having a channel therein for accommodating coolant circulation. In some embodiments, the system provides a cooling jacket that is wrapped around the antenna or portions of the antenna in order to externally cool the antenna (see, e.g., U.S. patent application No. 11/053,987; incorporated herein by reference in its entirety). In some embodiments, the system utilizes an energy transmission device having a conductive covering around the antenna in order to limit heat dissipation to the surrounding tissue (see, e.g., U.S. patent No. 5,358,515; incorporated herein by reference in its entirety). In some embodiments, when circulating the coolant, the coolant is output, for example, to a waste container. In some embodiments, the coolant is recirculated while the coolant is circulated.

In some embodiments, the system utilizes an inflatable balloon, along with an energy transmission device, to force tissue away from the antenna surface (see, e.g., U.S. patent application No. 11/053,987; incorporated herein by reference in its entirety).

In some embodiments, the system utilizes a device configured to be attached to the energy delivery device in order to reduce unwanted heat generation within and along the energy delivery device (see, e.g., U.S. patent application No. 11/237,430; incorporated herein by reference in its entirety).

VII recognition system

In some embodiments, the energy delivery system of the present invention utilizes an identification element (e.g., an RFID element, a bar code, etc.) associated with one or more components of the system. In some embodiments, the identification element communicates information about a particular component of the system. The invention is not limited by the information transferred. In some embodiments, the information communicated includes, but is not limited to, the type of component (e.g., manufacturer, size, energy consumption rating, organization configuration, etc.), whether the component has been previously used (e.g., to ensure that non-sterile components are not used), the location of the component, patient-specific information, and the like. In some embodiments, the information is read by a processor of the present invention. In some such embodiments, the processor configures other components of the system for use with, or optimally for use with, components containing the identification element.

In some embodiments, the energy delivery devices have indicia (e.g., score lines, color schemes, etching, pigmented contrast media indicia, and/or raised ridges) thereon to improve identification of particular energy delivery devices (e.g., improve identification of particular devices located in proximity to other devices having similar appearances). The marking is particularly useful in the case where multiple devices are inserted into a patient. In this case, it is difficult for the treating physician to correlate which proximal end of the device located outside the patient corresponds to which distal end of the device located inside the patient, especially if the devices intersect each other at various angles. In some embodiments, a marker (e.g., a number) is present at the proximal end of the device so that the marker is visible to the physician, and a second marker (e.g., a marker corresponding to the number) is present at the distal end of the device so that the second marker is visible to the imaging device when present in the body. In some embodiments, when a set of antennas is employed, the individual antennas of the set of antennas are numbered both proximally and distally (e.g., 1,2, 3,4, etc.). In some embodiments, the handles are numbered and a matching numbered removable (e.g., disposable) antenna is attached to the handles prior to use. In some embodiments, the processor of the system ensures that the handle and antenna are properly matched (e.g., by RFID tag or other means). In some embodiments, when the antenna is disposable, the system provides an alarm if an attempt is made to reuse the disposable component when it should have been discarded. In some embodiments, the markers improve identification in any type of detection system, including (but not limited to) MRI, CRT, and ultrasound detection systems.

The energy transfer system of the present invention is not limited to a particular type of tracking device. In some embodiments, GPS and GPS related devices are used. In some embodiments, RFID and RFID related devices are used. In some embodiments, a bar code is used.

In such embodiments, prior to use of a device having an identification element, authorization (e.g., entry of a code, scanning of a barcode) prior to use of such a device is required. In some embodiments, the information element identifies that an element has been previously used and sends information to the processor to lock (e.g., prevent) use of the system until a new sterile component is provided.

VIII temperature monitoring System

In some embodiments, the energy delivery system of the present invention utilizes a temperature monitoring system. In some embodiments, a temperature monitoring system is used to monitor the temperature of the energy transmission device (e.g., with a temperature sensor). In some embodiments, a temperature monitoring system is used to monitor the temperature of a tissue region (e.g., tissue being treated, surrounding tissue). In some embodiments, the temperature monitoring system is designed to communicate with the processor to provide temperature information to a user or to the processor to allow the processor to adjust the system appropriately.

IX. other Components

The system of the present invention may also employ one or more additional components that directly or indirectly utilize or facilitate the features of the present invention. For example, in some embodiments, one or more monitoring devices are used to monitor and/or report the functionality of any one or more components of the system. Additionally, any medical device or system that may be used directly or indirectly with the device of the present invention may be included as part of the system. Such components include, but are not limited to, sterilization systems, devices and components; other surgical, diagnostic or monitoring devices or systems; a computer device; manuals, instructions, labels and guides; a robotic device; and so on.

In some embodiments, the system employs pumps, reservoirs, tubing, wiring or other components that provide materials related to the connectivity of the various components of the system of the present invention. For example, any kind of pump may be used to supply the antenna of the present invention with a gaseous or liquid coolant. Gas or liquid treatment tanks containing a coolant may be employed in the system of the present invention.

In some embodiments, the energy delivery system (e.g., energy delivery device, processor, power source, imaging system, temperature adjustment system, temperature monitoring system, and/or identification system) and all associated energy delivery system application sources (e.g., cables, wires, cords, tubes, conduits that provide energy, gases, coolants, liquids, pressures, and communications) are provided in a manner that reduces undesirable performance issues (e.g., entanglement, clutter, and compromised sterility associated with the unorganized energy delivery system application sources). The invention is not limited to the particular manner in which the energy delivery system and the source of application of the energy delivery system are provided to reduce undesirable performance problems. In some embodiments, as shown in FIG. 13, the energy delivery system and energy delivery system application sources are organized using an input/output box 1300, a delivery cannula 1310, a process equipment hub 1320.

The present invention is not limited to a particular type or kind of input/output box. In some embodiments, the output/output tank contains a power source and a coolant supply. In some embodiments, the input/output box is located outside of the sterile field in which the patient is being treated. In some embodiments, the input/output box is located outside of a room in which the patient is being treated. In some embodiments, one or more cables connect the input/output box and the process equipment hub. In some embodiments, a single cable (e.g., a delivery cannula) is used. For example, in some such embodiments, the transfer sleeve contains components that transfer energy and coolant to and from the input/output tank. In some embodiments, the delivery cannula is coupled to the process equipment hub (e.g., extends below the surface of the ground, overhead) without causing physical obstructions to medical personnel.

The present invention is not limited to a particular type or kind of process plant hub. In some embodiments, a process plant hub is configured to receive power, coolant, or other elements from an input/output tank or other source. In some embodiments, the process device hub provides a control center that is physically located near the patient to implement any one or more of the following: providing energy to the medical device, circulating coolant to the medical device, collecting and processing data (e.g., imaging data, energy transmission data, safety monitoring data, temperature data, etc.), and providing any other functionality that facilitates a medical procedure. In some embodiments, the process equipment hub is configured to engage a delivery cannula to receive an associated energy delivery system application source. In some embodiments, the process device hub is configured to receive and distribute various energy delivery system application sources to applicable devices (e.g., energy delivery devices, imaging systems, temperature regulation systems, temperature monitoring systems, and/or identification systems). For example, in some embodiments, a process equipment hub is configured to receive microwave energy and coolant from an energy delivery system application source and distribute the microwave energy and coolant to the energy delivery equipment. In some embodiments, the process plant hub is configured to turn on or off, calibrate and adjust (e.g., automatically or manually) the number of particular energy transmission system application sources as appropriate. In some embodiments, the process plant hub has a power splitter therein that adjusts (e.g., manually or automatically turns on, turns off, calibrates) the number of particular energy delivery system application sources as appropriate. In some embodiments, the process plant hub has software therein for providing the energy delivery system application source in a desired manner. In some embodiments, the process device hub has a display area that indicates the relevant characteristics of each energy delivery system application source. In some embodiments, a processor associated with the energy delivery system is located in the process plant hub. In some embodiments, a power source associated with the energy delivery system is located in the process plant hub. In some embodiments, a process plant hub has sensors that automatically block one or more energy transmission system application sources when an undesirable event (e.g., undesirable heat generation, undesirable leakage, undesirable pressure changes, etc.) occurs.

In some embodiments, the process equipment hub is designed to be located in a sterile environment. In some embodiments, the process device hub is positioned on a patient's bed, a table on which the patient is positioned (e.g., a table for CT imaging, MRI imaging, etc.), or other structure near the patient. In some embodiments, the process equipment hub is disposed on a separate work bench. In some embodiments, the process device hub is attached to a ceiling. In some embodiments, the process device is centrally attached to the ceiling so that a user (e.g., a physician) can move it to a desired location (thereby avoiding having to place the energy transmission system application source (e.g., cables, wires, cords, tubes, conduits that provide energy, gas, coolant, liquid, pressure, and communication) on or near the patient during use). In some embodiments, the process device hub is configured to communicate (wirelessly or by wire) with a processor (e.g., a computer, with the Internet, with a cell phone, with a PDA). In some embodiments, the process plant hub has one or more lights thereon. In some embodimentsThe process plant hub is configured to compress the delivered coolant (e.g., CO) at any desired pressure₂) To maintain the coolant at a desired pressure (e.g., critical point of the gas) to improve cooling or temperature maintenance. For example, in some embodiments, the gas is provided at or near a critical point of the gas to maintain the temperature of the equipment, wiring, cables, or other components at a constant, specified temperature. In some such embodiments, the component itself is not cooled because its temperature does not drop from the starting temperature (e.g., room temperature), but is maintained at a temperature that is lower than the component would have been if there were no intervention. For example, it can be in CO₂Using CO at or near the critical point of₂To maintain the temperature such that the components of the system are cold enough not to burn tissue, but are not cooled or maintained at a temperature significantly below room or body temperature, such that skin in contact with the components is frostbitten or otherwise frostbitten. By utilizing this configuration, less isolation is allowed to be used because there is no "cold" component that must be isolated from a person or from the surrounding environment. In some embodiments, the process equipment hub has a retracting element for retracting the used and/or unused power, gas, coolant, liquid, pressure and/or communication cables, wires, cords, pipes, conduits. In some embodiments, the process equipment hub is configured to infuse the energy transmission equipment with coolant for distribution such that the coolant is at a desired temperature prior to use of the energy transmission equipment. In some embodiments, the process plant hub has software therein configured to prime the energy transmission device with coolant for distribution such that the system is at a desired temperature prior to use of the energy transmission device. In some embodiments, the use of a process equipment hub allows for the use of shorter cables, wires, cords, pipes and/or conduits (e.g., less than 4 feet, 3 feet, 2 feet). In some embodiments, one or more components, or portions thereof, of the process equipment hub and/or coupled thereto are covered by a sterile sleeve.

In an exemplary embodiment, the input/output tank contains one or more microwave power sources and a coolant supply (e.g., pressurized carbon dioxide gas). The input/output box is connected to a single transmission sleeve that transmits both microwave energy and coolant to the process equipment hub. The coolant or power lines within the delivery sheath may be intertwined to maximize cooling of the delivery sheath itself. The delivery cannula extends along the floor to the sterile field where the treatment procedure is performed, in a location that does not interfere with the activities of the medical team attending the patient. The delivery cannula is connected to a table located adjacent an imaging table on which the patient lies. The table is movable (e.g., with wheels) and is attachable to the imaging table so that they move together. The table contains arms that are flexible or telescoping to allow placement of the arms over the patient. The delivery cannula or a cable connected to the delivery cannula extends along the arm to an overhead position. The end of the arm is the process device hub. In some embodiments, two or more arms are provided with two or more process device hubs, or two or more subassemblies of a process device hub. The process device hub is small (e.g., less than 1 cubic foot, less than 10 cubic centimeters, etc.) for easy movement and placement over the patient. The process plant hub contains a processor for controlling all of the computational aspects of the system. The equipment hub contains one or more connection ports for connecting cables to the energy transfer equipment. The cable is connected to the port. The cable is retractable and has a length of less than 3 feet. The use of short cables can reduce cost and avoid power loss. When not in use, the cable is suspended in the air above the patient and does not come into contact with the patient's body. When not in use, the port is provided with a virtual load (e.g., when the energy transfer device is not connected to a particular port). The process device hub is within reach of the treating physician so that computer control can be adjusted and displayed information can be viewed in real time during the treatment process.

Use of energy transmission systems

The system of the present invention is not limited to a particular use. In fact, the energy transfer system of the present invention is designed for use in any environment where energy emission is suitable. Such uses include any medical, veterinary and research applications. In addition, the systems and apparatus of the present invention may be used in agricultural environments, manufacturing environments, mechanical environments, or any other application where energy is to be transferred.

In some embodiments, the system is configured for open surgical, percutaneous, intravascular, intracardiac, endoscopic, intraluminal, laparoscopic, or surgical energy delivery. In some embodiments, the system is configured to deliver energy to a target tissue or region. In some embodiments, a positioning plate is provided to improve percutaneous, intravascular, intracardiac, laparoscopic, and/or surgical energy delivery via the energy delivery system of the present invention. The present invention is not limited to a particular type or kind of alignment plate. In some embodiments, the positioning plate is designed to secure one or more energy delivery devices to a desired body site for percutaneous, intravascular, intracardiac, laparoscopic, and/or surgical delivery of energy. In some embodiments, the composition of the locating plate is such that exposure of the body part to unwanted heating from the energy delivery system can be avoided. In some embodiments, the locating plate provides guidance that helps locate the energy transmission device. The invention is not limited by the nature of the target tissue or region. Uses include, but are not limited to, treatment of cardiac arrhythmias, tumor ablation (benign and malignant), control of intraoperative hemorrhage, control of traumatic hemorrhage, any other bleeding control, removal of soft tissue, tissue removal and resection, treatment of varicose veins, intraluminal tissue ablation (e.g., treatment of esophageal lesions such as Barrett's esophagus and esophageal adenoma), treatment of bone tumors, normal skeletal and benign bone conditions, intraocular applications, applications in cosmetic surgery, treatment of central nervous system lesions (including brain tumors and electrical disorders), sterilization procedures (e.g., ablation of fallopian tubes), and cauterization of blood vessels or tissues for any purpose. In some embodiments, the surgical application includes ablation therapy (e.g., to achieve coagulative necrosis). In some embodiments, the surgical application includes tumor ablation of a target, such as a metastatic tumor. In some embodiments, the device is configured to be moved and positioned at any desired location, including (but not limited to) the brain, neck, chest, abdomen, and pelvis, with minimal damage to the tissue or organ. In some embodiments, the system is configured to achieve directional transmission by computerized tomography, ultrasound, magnetic resonance imaging, fluoroscopy, and the like.

In some embodiments, the present invention provides methods of treating a tissue region, comprising providing a tissue region and a system described herein (e.g., an energy delivery device, and at least one of a processor, a power source, a temperature monitor, an imager, a tuning system, and/or a cooling system); positioning a portion of the energy delivery device proximate to the tissue region, and delivering an amount of energy to the tissue region with the energy delivery device. In some embodiments, the tissue region is a tumor. In some embodiments, the delivery of energy results in ablation of the tissue region and/or vascular embolization, and/or electroporation of the tissue region. In some embodiments, the tissue region is a tumor. In some embodiments, the tissue region comprises one or more of a heart, liver, genitalia, stomach, lung, large intestine, small intestine, brain, neck, bone, kidney, muscle, tendon, blood vessel, prostate, bladder, and spinal cord.

Experiment of

Example 1

This example demonstrates that undesirable tissue heating is avoided by circulating coolant through the cooling channel using the energy transmission device of the present invention. The ablation needle shaft used for all experiments was 20.5 cm. The cooling of the handle assembly is minimal, indicating that the cooling effect of the handle is well insulated. Temperature probes 1,2 and 3 were all located adjacent to the tip 4,8 and 12cm of the stainless steel needle (see figure 9). Temperature measurements were taken 35% power measurements after insertion into the pig liver and 45% power measurements after insertion into the pig liver. For 35% power measurement, the probe 4 is on the handle itself. For 45% power measurements, the probe 4 is located at the needle-skin interface, approximately 16 cm from the stainless steel needle tip.

As shown in fig. 10, treatment at 10 minutes 35% power with featureless high (6.5%) reflected power indicates: at the probes 1,2, 3 and handle, the device is maintained at a temperature that does not damage the tissue.

As shown in fig. 11, treatment at 10 min 45% power with featureless high (6.5%) reflected power indicates: at probes 1,2, 3 and 4, the device is maintained at a temperature that does not damage the tissue. Skin and fat layers were observed after 10 minutes ablation at 10 minutes 45% power with featureless high (6.5%) reflected power, indicating no visible burns or thermal damage.

Example 2

This example demonstrates the calibration of the generator. The generator calibration is done at the factory with Cober-Muegge and is set to be very accurate for powers greater than 150W. The magnetron acts much like a diode: increasing the cathode voltage does not increase the vacuum current (proportional to the output power) until a critical threshold is reached, at which the vacuum current increases rapidly with voltage. The control of the magnetron source relies on accurate control of the cathode voltage near the critical point. Thus, the generator is not specified for 0-10% power, and below 15%, the correlation between output power and theoretical power percentage input is poor.

To test the generator calibration, the power control dial was changed from 0.25% in 1% increments (corresponding to theoretical output powers of 0-75W in 3W increments), the output power display of the generator was recorded, and the power output was measured. The measured power output is adjusted to account for measured losses of the coaxial cable, coupler and load at room temperature. The output display is also adjusted for offset error (i.e., when the dial is set to 0.0%, the generator reading is 2.0%).

For low power dial settings, the error between the dial and the generator output power display is large. For dial settings above 15%, these two values quickly converge to a percentage error of less than 5%. Similarly, the measured output power is significantly different from the theoretical output power for turntable settings below 15%, but more accurate for turntable settings above 15%.

Example 3

This example illustrates the placement and testing of the antenna during the manufacturing process. This provides a setup and test method in a manufacturing environment. The method uses a liquid, tissue-equivalent manikin rather than tissue.

Based on numerical and experimental measurements with the antenna turned off, it is known that a 1mm change in L2 will increase the reflected power from < -30dB to-20-25 dB. The change in tissue properties that occurs during ablation may make this increase less significant, so we would consider a relative tolerance of 0.5mm for length L2 reasonable. Likewise, even though the overall reflection coefficient is less dependent on L1 than L2, a tolerance of 0.5mm with respect to length L1 is used.

Testing of antenna tuning for quality control can be achieved using liquid solutions for modeling the dielectric properties of the liver, lung or kidney (see, e.g., Guy AW (1971) IEEE trans. micro. thermal tech.19: 189-. The antenna is immersed in the phantom and the reflection coefficients are recorded using a 1-port measurement device or a full Vector Network Analyzer (VNA). A reflection coefficient verification below-30 dB was chosen to ensure correct tuning.

All publications and patents mentioned above in this specification are herein incorporated by reference. Various modifications and variations of the described methods and systems of the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. While the invention has been described in connection with specific embodiments, it will be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.

Claims (31)

1. An apparatus comprising an antenna for delivering energy to tissue, the antenna having a cooling channel disposed in an inner or outer conductor of a coaxial cable.

2. A device comprising an antenna for delivering energy to tissue, the antenna comprising an expandable material that changes volume in response to heat, wherein the change in volume changes an energy delivery characteristic of the antenna.

3. The apparatus of claim 2, wherein the antenna comprises a center-fed dipole, and the swellable material is contained within the center-fed dipole.

4. A device comprising an antenna for delivering energy to tissue, the antenna comprising first and second chemicals which, when in contact with each other, produce an endothermic reaction for cooling the antenna.

5. The apparatus of claim 4, wherein the first and second chemicals are separated from each other by a barrier.

6. The apparatus of claim 5, wherein the barrier is configured to be removed in response to heat.

7. The apparatus of claim 4, wherein said first and second chemicals are pre-loaded into said antenna prior to use.

8. Apparatus according to claim 4, wherein, in use, said first and second chemicals are supplied to said antenna.

9. An apparatus comprising an antenna to transmit energy to tissue, the antenna comprising one or more cooling tubes inserted within a coaxial cable, the cooling tubes configured to deliver a coolant to the antenna.

10. The apparatus of claim 9, wherein the one or more cooling tubes are between the outer conductor and the dielectric material of the coaxial cable.

11. The apparatus of claim 9, wherein the one or more cooling tubes are between the inner conductor and the dielectric material of the coaxial cable.

12. The apparatus of claim 9, wherein the one or more cooling tubes are within the inner conductor or the outer conductor.

13. An apparatus comprising an antenna for delivering energy to tissue, the antenna comprising two or more sections separated by a gap in an outer conductor of a coaxial cable, the gap filled with a resin.

14. The apparatus of claim 13, wherein the resin comprises a curable epoxy resin.

15. An apparatus comprising an antenna for delivering energy to tissue, wherein the antenna comprises a coaxial cable, and wherein the antenna has a non-circular cross-sectional shape.

16. The apparatus of claim 15, wherein the coaxial cable has a non-circular cross-sectional shape.

17. The apparatus of claim 16, wherein the dielectric component of the coaxial cable has a non-circular shape.

18. A system, comprising:

a) a power source assembly providing an energy source and a cooling source;

b) a transmission assembly for transmitting energy and coolant from the power source assembly to the control hub; and

c) a portable control hub receiving energy and coolant from a transmission assembly, the control hub disposed on a movable arm positionable above a patient workspace; the control hub includes: i) a processor for regulating energy and coolant delivery to a plurality of energy delivery devices; and ii) a plurality of connection ports connected to cables for transmitting energy to the energy transmission device.

19. The system of claim 18, wherein the power source is located outside of the sterile zone and the control hub is located within the sterile zone.

20. The system of claim 18, wherein the power source supplies microwave energy.

21. The system of claim 18, wherein the power source supplies radio frequency energy.

22. A system for monitoring and controlling ablation therapy, comprising: a) one or more ablation devices for tissue ablation of a subject; and b) a processor running an imaging and control program, the program comprising: a component for monitoring the position of the one or more ablation devices; a component for monitoring a state of tissue in proximity to the ablation device; and a component for reporting tissue status information to medical personnel.

23. The system of claim 22, wherein the one or more ablation devices comprise a microwave energy delivery device.

24. The system of claim 22, wherein the one or more ablation devices comprise a radio frequency energy delivery device.

25. The system of claim 22, wherein the processor provides a component for displaying a representation of the tissue region.

26. The system of claim 25, wherein said processor further provides a component that allows a user of the system to select an area of the zone to be ablated on said displayed representation.

27. The system of claim 26, wherein the processor further provides a component for automatically processing the selected area.

28. The system of claim 27, wherein the automated process comprises energy delivery control.

29. The system of claim 27, wherein the automated process comprises monitoring tissue status at one or more points in time.

30. The system of claim 29, wherein said monitoring tissue comprises monitoring the location of contrast agent in said tissue.

31. The system of claim 22, wherein the program component is provided by software run by the processor.