HK1135869B - Transport system for biopsy device - Google Patents

Description

Delivery system for biopsy device

The present application is a divisional application of the invention patent application having application number 2005800294305, application date 2005-07-08 entitled "delivery System for biopsy device".

Technical Field

The present invention relates to a biopsy device (biopsy device) for harvesting tissue samples of a human or animal body. The present invention relates particularly, but not exclusively, to percutaneous biopsy, in which it is desirable to contact the tissue mass to be examined in a minimally invasive manner. More particularly, the present invention relates to delivering a sample-receiving device containing one or more harvested tissue samples into an external hollow needle of a biopsy device.

Background

For diagnostic purposes, it may be desirable to obtain tissue samples of the human or animal body for in vitro cytological (histological) and/or histological examination. Tissue sampling may be performed using open or percutaneous techniques. In the open technique, the entire tissue mass to be examined is removed (excisional biopsy) or a part of the tissue mass to be examined is removed (excisional biopsy). Basically, a scalpel is used to contact the lesion and remove it, and if very invasive, an open biopsy is a reliable method of obtaining a tissue sample.

In the percutaneous technique, a needle is used to contact the tissue mass to be examined in a less invasive manner. The needle may be hollow, allowing single cells and tissue debris to be drawn into the lumen by application of a vacuum (needle biopsy). Alternatively, larger tissue cores may be obtained using a needle having a movable inner trocar with an incision formed to receive the tissue core, and a slidable outer cannula with a sharp distal end for severing the core from surrounding tissue (core needle biopsy). The tissue sample may be severed and retained in the incision by advancing the inner trocar into the suspected lesion and then fully covering the incision with the slidable outer cannula. The needle is then retracted from the patient's body and the tissue sample may be collected and stored for further analysis.

Due to their simple use and versatility, core needle biopsy devices are the preferred tool for physicians. The core needle assembly can be applied to a wide range of different tissues and different anatomical locations and provides the pathologist with a sample suitable for tissue analysis for accurate diagnosis and analysis of the mass to be examined.

In obtaining core tissue samples, an important goal is to obtain the largest possible sample size. Prior biopsy systems have used vacuum to engage and pull tissue toward the incision or tissue receiving cavity or basket of the biopsy device prior to severing. Thus, given a biopsy needle diameter, the tissue sample size can be significantly increased, or a larger sample can be taken at the same needle diameter, to improve diagnostic accuracy.

Another known prior art technique to increase the size of a sample is to take multiple samples to obtain sufficient tissue for reliable diagnosis. To accomplish this with suction, core needle biopsy devices or single-action vacuum assist devices may only be inserted through multiple devices, resulting in greater patient pain, time consuming and bleeding risk.

In the area of chest biopsy, this problem has been addressed with improvements in biopsy systems that enable an operator to extract multiple samples using a single biopsy device insertion. These biopsy devices essentially apply vacuum to engage and draw the appropriate amount of tissue into the hollow portion of the instrument. The power and vacuum supply units to which these multiple biopsy devices are attached are housed in a separate vacuum workstation that requires cart transport as well as hoses and wires to function properly. The physical connection between the biopsy device and the attached vacuum/power supply unit means that the freedom of movement of the operator or physician is limited and the auxiliary device also takes up storage and floor space.

In prior art biopsy systems and devices, tissue sample extraction, ejection and subsequent storage of individual tissue samples has been accomplished in several different ways. Some biopsy devices include mechanical extraction and ejection of extracted tissue samples, as described in US 5526822. The biopsy device captures and holds a tissue sample in the lumen of a rotatable cutting cannula that is retractable to a point outside the patient's body. The captured tissue sample is pushed out of the lumen of the cannula using a spray bar.

Other prior biopsy devices are characterized by vacuum-driven extraction and ejection of tissue samples. US6638235 discloses a biopsy device with a rotary cutting inner cannula which enables multiple tissue samples to be taken in a single cannula insertion. The device reduces the labor of the operator by enabling multiple tissue samples to be automatically drawn and collected in a collection chamber placed outside the patient's body. The tissue sample is drawn from the sampling site and moved through the inner lumen of the cutting cannula to the collection lumen by vacuum drawn through the collection lumen and the inner lumen of the cutting cannula.

In the sampling, collection and storage of certain types of tissue samples, such as prostate tissue samples, it is desirable that the individual tissue cores or samples drawn remain separate if the subsequent diagnosis is valid.

Disclosure of Invention

It is an object of a preferred embodiment of the present invention to provide a biopsy device and method which may allow sampling, preferably in an automated manner. It is a further object of a preferred embodiment of the present invention to provide biopsy apparatus and methods that allow for easy penetration of a tissue mass to be examined. It is a further object of a preferred embodiment of the present invention to provide a biopsy device and method that allows for convenient severing of a tissue sample. It is a further object of a preferred embodiment of the present invention to provide a biopsy device and method that facilitates the handling of a tissue sample taken by a physician. It is a further object of a preferred embodiment of the present invention to provide a biopsy device that is easily manipulated by a physician. It is a further object of a preferred embodiment of the present invention to provide a biopsy device and method that allows for the storage of individually separated tissue samples in a preservative.

In a first aspect, the present invention provides a biopsy device for obtaining at least one tissue sample from a living organism, the device comprising: a biopsy device for obtaining at least one tissue sample from a living organism, the device comprising: a hollow needle with a distal portion adapted for introduction into the living body; a cutting mechanism for severing the at least one tissue sample; a sample-receiving device with a cavity for receiving the at least one excised tissue sample, the sample-receiving device being receivable into and movable within the hollow needle; a delivery device for moving the sample-receiving device within the hollow needle between a first extended position in which the sample-receiving device with the cavity is in a distal position and the cutting mechanism can cut off the at least one tissue sample, and a second retracted position in which the sample-receiving device with the cavity is in a proximal position, the delivery device comprising a bendable elongate element, the sample-receiving device being movable within the hollow needle along an axis of motion, and at least one of the hollow needle and the sample-receiving device being configured to orient the sample-receiving device relative to the hollow needle in a plane substantially perpendicular to the axis of motion.

The conveyor (or transport mechanism) can be coupled with a cutting mechanism and a compact drive system with all the required controls and mechanisms. An optional vacuum supply unit for drawing tissue into (or aspirating) the sample-receiving chamber may be integrally formed with the handle unit or may be provided in an external or separate unit. The transport mechanism preferably enables multiple tissue samples to be collected and removed in a quick, efficient and reliable procedure. The cutting mechanism preferably allows for rapid and efficient severing of the tissue sample. This can be achieved, for example, with a rotating knife of a spring-loaded mechanism, although electrocautery can also be applied. The handle unit may comprise a drive which transmits the required driving force and movement to the conveying and cutting mechanism. This may be achieved, for example, by several means, most commonly a spring, motor or aerodynamic drive.

The delivery device of the present biopsy device may comprise any suitable system for moving the sample-receiving device within the hollow needle, i.e. capable of pulling the sample-receiving device from a first extended (i.e. distal) position to a second retracted (i.e. proximal) position and capable of pushing the sample-receiving device from the second retracted position to the first extended position. The transport device for moving the sample-receiving device within the hollow needle comprises a bendable elongated element, such as a steel wire, two or more twisted wires, such as a Bowden cable or any other flexible or bendable element. The elongate member is preferably bendable away from the longitudinal direction of the hollow needle, i.e. transversely bendable, and preferably sufficiently stiff or sufficiently supportive in the transverse direction to prevent outward flexing of the bendable elongate member when the sample containment device is pushed from the second retracted position to the first extended position.

Preferably, a winding means is provided for winding the bendable elongate element, the winding means preferably being provided at a proximal end of the device, such as at least the proximal end of the second retracted position. In embodiments where the bendable elongate element is included in a disposable unit, the bendable elongate element may be attached to, for example, a handle unit or a stationary unit of a biopsy device, the winding device preferably being integrated in the disposable unit, as described in more detail below.

The bendable elongate element may have a longitudinal extension of circular or non-circular cross-section, for example a polygonal cross-section such as triangular or rectangular. The polygonal cross-section gives the possibility that the bendable elongated elements may be toothed for engagement by the driving gear. Thus, in one embodiment, the bendable elongate element includes a row of regularly spaced teeth extending substantially perpendicular to the longitudinal axis of the elongate element. In this embodiment, the biopsy device may have a rotatable gear with a toothed rim for interacting with the teeth of the elongate member to move the elongate member along the longitudinal axis in the hollow needle. One or more supports may be provided for supporting the bendable elongated element in a transverse direction to avoid flexing thereof, the supports comprising for example two opposite wall regions provided with a mutual gap corresponding to the thickness of the bendable elongated element, which is free to slide between the wall regions in a longitudinal direction. Similarly, the bendable elongate element slides between the opposing roller elements.

To allow the sample-receiving device to rotate relative to the bendable elongate element, the sample-receiving device may be secured or attached to the bendable elongate element using a swivel joint.

From the above discussion, it will be appreciated that the sample-receiving device may have a length that is substantially shorter than the length of the hollow needle, and that the distal end of the bendable elongate element may be attached to the proximal end of the sample-receiving device, such that the bendable elongate element causes the sample-receiving device to move within the hollow needle.

It will also be appreciated that the biopsy device of the invention may comprise a handle unit with a power source and a motor for driving the delivery device, and that the delivery device, the hollow needle and the sample receiving device may be comprised in a disposable unit which is releasably secured to the handle unit. The drive interface is preferably arranged to transmit the driving force of the motor in the handle unit to the bendable elongate element in the disposable unit.

Since the bendable elongate element moves within the hollow needle, the inner wall thereof may contact the tissue sample as it moves within the cavity of the sample containment device, and the winding device may be contaminated by living tissue and/or body fluids during tissue sample acquisition. The winding device may form a helix, whether or not the winding device is included in a disposable unit or other part of the biopsy device, such as a handle unit. The helical wire may be formed by, for example, at least one wall element arranged such that contact between the coiled portions of the bendable elongate element is prevented to avoid uncontrolled bending or dimensional change of the coiled bendable elongate element.

Embodiments of the biopsy device of the invention forming a handheld unit preferably also include a delivery device, such as a bendable elongate element, in the handheld unit. It will be appreciated that the handle unit is preferably embodied as a hand-held unit which accommodates all required power, liquid and vacuum sources and possible drive mechanisms for the needle and sample holder and firing mechanism, as will be described below. In general, the entire biopsy device of the invention may be comprised in a handheld unit, comprising a hollow needle, a cutting mechanism, a sample receiving device, a transport device, an optional liquid supply unit and all other structural elements mentioned herein.

Further embodiments and features will become apparent from the following description. The transfer of the sample from the sampling point or point (or location for taking) to the collection point or location (or sample ejection) is preferably carried out by means of a flat toothed rod, preferably made of a polymeric material such as polypropylene, to which the sample-receiving means is attached, in the form of a container, for example a canoe, to retain the tissue sample once it has been severed. The sample-receiving device may have laterally facing openings for receiving tissue samples and may have one or several vacuum ports to enable tissue to be drawn into the sample-receiving device by the application of a vacuum. With the biopsy device positioned in the tissue to be sampled, the severing of the tissue sample can be performed with a coaxial piston system comprising a spring-loaded outer cutting cannula (i.e. a hollow needle) with a sharp distal end (i.e. a circumferential cutting edge) and capable of axial movement, and an inner guide cannula with a sharp tip capable of penetrating the tissue. The inner guide sleeve may be non-movable by the delivery device described herein or movable thereby. The inner cannula may have a laterally facing cut-out (or cavity) that enables tissue to escape into the lumen of the cannula and into the waiting sample-receiving device. The sample-receiving device and/or the severed tissue sample delivery system may be axially movable within the lumen of the inner cannula, for example, to advance and retract the sample-receiving device. The power for driving the transport mechanism may be delivered by an electric or pneumatic driver unit. The expulsion and discharge of the sample from the sample-receiving device into a suitable transport container may be carried out with liquid or pressurized air at the point of collection (or ejection).

The bendable elongate element may comprise a flat bar toothed on one side and may be made of a suitable polymeric material, such as polypropylene or Nylon^TM. The bendable elongate element is longitudinally movable within the inner cannula system and is capable of transporting a tissue sample from a capture position at a distal tip of the biopsy device, such as a first extended position of the sample containment device, to a ejection point, such as a second retracted position of the sample containment device. It can be tightly fitted to the wall of the inner sleeve to ensure lateral rigidity into the inner sleeve. The cavity on the upper side may enable a vacuum to be applied to the distal end of the system. The distal point of the inner cannula system may feature a connection means to temporarily couple the inner cannula with a tissue mass to be examined, such as a tumor.

The bendable elongated element (or rod) may be coupled to the sample-receiving device with a vacuum valve. The vacuum valve can have several different configurations depending on the application and design of the evacuation (i.e., irrigation) chamber. The flat toothed rod may establish a vacuum channel in the inner sleeve. The sample containment device may contain tissue during a sampling procedure and hold the sampled tissue on its way from the point of sampling or acquisition to the point of collection. A filter or mesh may be provided to ensure that no tissue escapes from the container.

Since the sample-receiving device is ready to be emptied (or sprayed), the coupling mechanism between the toothed bar and the sample-receiving device may allow for rotational movement of the sample-receiving device relative to the flat bar to facilitate the emptying procedure.

The toothed rod may interact with the pinion allowing the rotational movement of the pinion to be translated into a linear movement of the toothed rod to enable withdrawal of the obtained tissue sample and positioning of the sample containment device in the inner cannula system, i.e. in the hollow needle. The pinion may be metallic or ceramic to ensure durability.

The motor for driving the sample holder or pinion may be an electric motor. Two batteries and a switch (on/off switch) may be provided for starting and driving the motor. The motor may be pneumatic, which may make the system MRI compatible.

The winding means may comprise a spool-like member placed in the handle to enable the toothed rod to wind as it is retracted. Thus, the toothed rod will not protrude further beyond the proximal end of the delivery mechanism. This is an advantage especially when taking living tissue at deeper anatomical depths. Alternatively, the toothed bar may be bent away from its longitudinal direction.

A guide wheel may be included to stabilize the flat bar and sample containment device as the assembly is advanced into the inner sleeve system.

The driver unit of the biopsy device may comprise the following components: one or more motors integrated in a suitably designed handle. The motor may basically have two main functions, namely advancing and retracting the flat toothed bar and sample containment device when the sample is ready for cutting, and cocking and releasing the firing mechanism. Once the system is put into operation, cocking of the cutting mechanism may automatically result in retraction, emptying and extension of the sample containment device that automatically follows the firing of the cutting mechanism. Control of the device may result from, for example, depression of a pedal or selection of a button. The driver unit may be electrically or pneumatically driven and is preferably a self-contained, fully autonomous unit with its own power source, vacuum source and tissue collection container. May be configured to enable (by selection) one or more of the following modes of operation: step, semi-automatic or fully automatic.

The vacuum supply and evacuation mechanisms may be an integral part of the handle housing the driver unit, or they may be placed in an external unit. The discharge mechanism (or jet system) may use air pressure, water flushing, or a third method of discharging the tissue.

As a spare for the toothed bar, a wire such as a steel wire may be used as the conveying mechanism. The steel wire may be a single wire or it can have two or more twisted wires with or without a core wire, a principle known from so-called Bowden cables. The Bowden cable may be wound as described above. In order to be able to function such a wire, the bobbin for winding the wire may have a groove in its surface adapted to the dimensions of the wire, and the coil may be suspended in a closely mounted receiving unit, thereby forming a channel for the wire. The use of a hard wire in combination with the appropriate channel enables the sample-receiving device to be retracted and advanced within the guide inner cannula.

In the default position of the biopsy device, the flat bar with the sample receiving device can be extended maximally and the sample receiving device can be placed in the distal end of the cutting system. The outer cannula may be extended maximally to cover the tissue receiving port in the inner cannula as the system is advanced into the patient.

When the sampling sequence is initiated, the driver unit may be activated to initiate cocking of the spring-loaded firing mechanism, as described in more detail below, and the outer cannula may be pulled toward the proximal end of the device, opening the tissue receiving port. Once the outer cannula has been retracted to open the tissue receiving port, a vacuum can be applied to the inner lumen of the inner cannula, drawing tissue into the tissue receiving port and into the sample containment device.

After the cutting mechanism has been retracted, the sample acquisition mechanism can release the spring-loaded firing mechanism, causing the outer cannula to advance rapidly, severing the tissue sample. After severing the tissue sample, the flat toothed rod with the sample-receiving device may be retracted and carry the biopsy sample to a collection (or ejection) point.

A mechanism at the proximal end of the inner sleeve can engage and rotate the sample-receiving device as it exits the inner sleeve to facilitate the expulsion (or ejection) of the sample. As the sample-receiving device enters the exit chamber, fluid flow may be automatically released to flush the tissue sample out of the sample-receiving device and into a suitable container. The flushing liquid is preferably saline, possibly containing additives for preserving the sample or preparing it for the experiment.

After the ejection cycle has been completed, the flat toothed rod and sample containment device are advanced and the sample containment device may be positioned in the distal end of the inner sleeve, ready for a new cycle. After the sampling sequence is complete, the outer cannula may be left in a default position to close the tissue receiving port in preparation for removal of the biopsy needle. The tissue storage container may be removed from the biopsy device and sent to a pathologist for further analysis.

The tip of the sample-receiving device may be conical and may be configured to function as a penetration point, a tissue-receiving port, a sample container, and a cutting plate.

In the present invention, the outer diameter of the biopsy needle may be in the range from 0.5 mm to 5.0 mm, such as in the range from 1.2 mm to 3.0 mm. Biopsy needles are typically made of stainless steel, but other materials compatible with MRI, such as titanium, may be used.

In order to accurately control the movement of the sample-receiving device in the hollow needle, the sample-receiving device and the hollow needle may be shaped such that a relative rotational movement between the sample-receiving device and the hollow needle in said plane is prevented. For example, the outer cutting cannula or hollow needle may comprise first orientation means adapted to co-act with matching second orientation means of the sample accommodating means to guide and orient the sample accommodating means inside the outer cutting cannula in a plane substantially perpendicular to the axis of movement of the sample accommodating means. The orientation means may ensure that the sample ejection aperture of the sample receiving means is reliably positioned in a plane substantially perpendicular to its axis of movement, thereby supporting automatic ejection of the extracted tissue sample. For example, the elliptical cutting cannula and sample-receiving device may have an elliptical profile, or an inward protrusion may be provided on the inner wall of the cutting cannula (outer needle) that engages a corresponding groove in the sample-receiving device.

The biopsy device of the invention may comprise a liquid supply unit adapted to comprise a flushing liquid, which liquid supply unit may be operatively connected to the cavity of the sample holding device by means of a hollow liquid transport member, thereby allowing for spraying of the tissue sample by means of liquid flushing.

The liquid supply unit as described above allows for a careful handling of the at least one taken tissue sample during a biopsy procedure and subsequent re-taking of the taken tissue sample to keep the structure of the tissue to be examined intact and to allow for an accurate diagnosis. Furthermore, the separately drawn tissue cores or samples may advantageously be separated to enable better diagnostic capabilities. This is advantageous in connection with most kinds of tissue samples, such as prostate samples. In addition, the liquid flushing to eject the at least one tissue sample from the cavity of the sample-receiving device allows for an automated, rapid biopsy procedure, with minimal trauma to the patient and minimal manual handling of the acquired tissue sample by the physician.

The irrigation liquid is preferably a preservative, wherein the obtained tissue sample will be stored after ejection from the cavity of the sample-receiving device. The flushing liquid may for example comprise saline or formalin. It will be appreciated that since the spray may be caused solely by the action of the rinsing liquid, non-harsh treatment of the biopsy sample, e.g. by forceps, is required in order to remove the retrieved tissue sample from the cavity of the sample holding device. The cavity may have a substantially circular cross-section. Particularly advantageous embodiments of the biopsy device of the present invention may be fully handheld and include integral vacuum and liquid supply mechanisms and power sources, thereby eliminating any need for separate (or external) vacuum, fluid and power sources. Alternatively, the vacuum supply and/or power source may be located external to the biopsy device and connected thereto by suitable power conductors and vacuum hoses.

In one embodiment, the biopsy device of the present invention includes a closed system for tissue sample extraction and delivery to avoid leakage of bodily fluids, operator exposure to biohazards, and contamination of the extracted tissue sample. This embodiment ensures that manual handling of the extracted tissue sample is minimized and thus ensures that possible handling damage is minimized.

The hollow needle preferably defines a longitudinally extending annular body portion defining a co-extending longitudinal cavity in the hollow needle, and the cavity in the sample acquiring device may have a transverse opening for receiving the at least one tissue sample.

In one embodiment of the invention, the cutting mechanism comprises a circumferential cutting edge at the distal end of the hollow needle, as described in more detail below. In order to allow the circumferential cutting edge to sever an effective tissue, the sample-receiving device and the hollow needle are preferably movable relative to each other, so that the sample-receiving device can assume a protruding position, in which it protrudes from the distal tip of the needle, and a retracted position, in which it is received in the hollow needle, and the distal end of the device is defined by said circumferential cutting edge and possibly the conical tip of the sample-receiving device.

In order to aspirate or draw living tissue into the cavity of the sample-receiving device, the biopsy device according to the invention preferably comprises a vacuum pump for generating a suction effect in the cavity of the sample-receiving device, which vacuum pump is in fluid communication with the cavity of the sample-receiving device via a longitudinally extending channel in the sample-receiving device and/or via a longitudinally extending channel defined by the hollow needle. For example, one or more vacuum ports may be provided in the bottom of the sample-receiving device, such as in a wall region defining the bottom of a cavity in the sample-receiving device, through which the cavity is in fluid communication with the interior of a hollow needle, which in turn is in fluid communication with a vacuum pump. Alternatively, one or more vacuum ports may be provided in the side wall forming a side portion of a cavity in the sample-receiving device through which the cavity is in fluid communication with the interior of the hollow needle or with a longitudinally extending passage in the sample-receiving device which is in fluid communication with a vacuum pump. Preferably, the vacuum pump is only operated during a short period of time each time a tissue sample is taken, i.e. shortly before severing the tissue sample. The vacuum pump may be operatively coupled to the control of the severing mechanism and/or to the control of the delivery device, for example, such that the vacuum pump is operative only when the sample-receiving device is in its first extended position, or for a predetermined period of time after the sample-receiving device has reached the first extended position, or for a predetermined period of time before the severing mechanism initiates severing of the tissue sample. Alternatively, the control of the vacuum pump may be coupled to the control of the cutting mechanism, for example such that the vacuum pump is activated when the hollow needle is retracted to expose the cavity of the sample containment device, compare the following description of the firing mechanism for severing a tissue sample, and such that the operation of the vacuum pump is stopped when a tissue sample has been severed.

The at least one tissue sample obtained by the biopsy device of the present invention is preferably obtained in an automated manner, extracted from the patient's anatomy, ejected from the sample-receiving device, and individually placed in a storage and/or preservative in a suitable tissue storage container. The operator (or pathologist) then focuses on optimizing tissue sampling and minimizing patient distress.

In the biopsy device of the invention, the liquid supply unit may be operatively connected to the cavity of the sample-receiving device when the sample-receiving device is in its second, retracted position, and preferably disconnected from the cavity of the sample-receiving device when the sample-receiving device is in its first, extended position. The first extended position is generally a position in which tissue is collected in the cavity of the sample-receiving device as the severing mechanism severs the tissue sample, i.e., the first extended position in which the sample-receiving device with its cavity is in a distal position. The second retracted position is a proximal position in which the captured tissue sample may be ejected from the cavity of the sample-receiving device. Preferably, a pump for pumping liquid from the liquid supply unit to the cavity of the sample-receiving device is integrated in the biopsy device. The pump may advantageously comprise a relatively inexpensive peristaltic pump. For example, the peristaltic pump may be incorporated into a handle portion of the device. In one embodiment, the peristaltic pump is releasably attached to a handle portion of the biopsy device, thereby facilitating replacement of the liquid supply unit as the peristaltic pump engages a portion of the hollow liquid transport member (e.g., a plastic or elastic hose or tube). In one embodiment, a clamping mechanism is provided which holds the hollow liquid delivery member and peristaltic pump together tightly, the clamping mechanism preferably being releasable by hand. Alternatively, or in addition to the peristaltic pump, the liquid supply unit may comprise a syringe-like liquid supply chamber and a plunger movably arranged in the liquid supply chamber. As with the pump, the liquid supply unit may be releasably secured to the handle unit, allowing it to be easily replaced.

The biopsy device of the invention may comprise a handle unit which houses or incorporates a power source, such as a battery pack, and a motor for driving the delivery device. The handle unit preferably does not incorporate means or elements that physically contact the living tissue, bodily fluids, or patient anatomy during tissue harvesting, so that the handle unit can be reused, i.e., used for several biopsy procedures each involving the extraction of multiple tissue samples from a patient. The delivery device, hollow needle and sample-receiving device are preferably included in a disposable unit releasably secured to the handle unit as part of the same or unavoidable contact with living tissue, body fluids or anatomical tissue of the patient during tissue acquisition. The disposable unit is often used for single biopsy procedures, and for the processing of one or more tissue samples taken from a site of acquisition in the patient's anatomy. As will be described in detail below, once the outer hollow needle of the disposable unit is in place at the access site, multiple tissue samples can be obtained without replacing the disposable unit, using the preferred embodiment of the biopsy device.

A flushing chamber may preferably be provided in the disposable unit, which flushing chamber is adapted for connection of the sample-receiving container to the biopsy device. Thus, the sample-receiving device is preferably aligned with the flush chamber in the second retracted position, however other arrangements are contemplated in which the tissue sample being obtained is transported from a cavity in the sample-receiving device to the flush chamber and from the flush chamber to the sample collection container using the flush liquid. The sample collection container may define at least one cavity, and preferably a plurality of cavities, for receiving the captured tissue sample, such that when the sample-receiving device is in the second retracted position, one or more of the cavities may be in communication with the cavity of the sample-receiving device. The sample collection container is preferably releasably attached to the disposable unit. The at least one cavity for receiving a tissue sample may, for example, comprise several cavities for receiving a single tissue sample, the sample collection container further comprising a movement or rotation mechanism for changing the relative position of the cavities with respect to the sample-receiving device, such that different tissue samples taken at different times may be flushed into the separate cavities. For example, the cavities may be circumferentially arranged on a rotatable disc, the rotation of which is controlled by a control system of the biopsy device (or biopsy system) to automatically align a subsequent container cavity with the flushing chamber and/or the sample receiving device when a biopsy sample has been ejected into the previous container cavity.

The sample collection container, also referred to as a "tissue storage container", may for example have a volume of 10-100 ml, such as 20-30 ml. The liquid supply unit or liquid container may for example have a volume of 5-30 ml, such as 5-15 ml, such as approximately 10 ml.

The flush chamber may be connected to an outlet valve of a fluid supply unit which may be pressurised as described. An opening in a wall of the flushing chamber allows liquid to move from the pressurized liquid supply unit to the flushing chamber. On the side of the irrigation lumen, opposite the pressurized liquid supply opening, a drainage tube may be provided leading to a tissue storage container separately storing the obtained tissue sample. The drain may be opened and closed by a slide valve or another suitable closing mechanism.

The irrigation liquid impinges on and expels a tissue sample held in the cavity of the sample-receiving device, which is ejected through the cavity of the sample-receiving device. The irrigation liquid then carries the tissue sample through the drain tube and into the tissue storage container. The flow of irrigation liquid into and out of the irrigation chamber may be controlled by operation of a slidable valve. In one embodiment, the slidable valve is operably connected to a valve spring that ensures that the valve in its default position closes the opening to the pressurized fluid supply and the drain to the tissue storage container. Alternatively, a delivery device for moving the sample-receiving device in the hollow needle, which delivery device comprises, for example, a bendable elongate element, may cause the opening and closing of the valve. A part of the delivery device may then interact with the valve or with the means for opening and closing the valve. Generally, endolumenal means may be provided that prevent the drawing of irrigation liquid into the hollow needle when a vacuum is applied to draw tissue into the cavity of the sample-receiving device.

The sample-receiving device or the transport device contacts the slidable valve when the sample-receiving device is moved toward the second retracted position. Continued retraction of the sample-receiving device causes the slidable valve to be pushed toward the rear side of the flush chamber, so that both the opening to the liquid supply unit and the drain to the tissue storage container are open. This operation allows fluid to enter the flush chamber and the sample to move through the drain tube into the storage container. During this process, the valve spring accumulates potential energy, or electrical energy, by mechanical compression. After the tissue sample has been flushed out of the sample containment device, once again advanced toward the first extended position, the valve is closed, for example, by the release of electrical energy or potential energy stored in the spring.

The tissue storage container may be substantially circular and include a plurality of individually identifiable cavities, wherein each cavity is adapted to receive a tissue sample. The storage container may include a movable portion, such as a handle unit, operatively connected to a suitable drive mechanism in the driver unit, thereby allowing the cavity to be automatically changed as the biopsy procedure is performed and multiple tissue samples are taken. Thus, a single tissue sample is preferably captured in each chamber, and subsequent alteration of the chambers ensures that each tissue sample and its associated stored fluid are enclosed in the tissue storage container.

The individual tissue samples may then be identified by their respective placement in the sample-receiving device, and the individual cavities may in turn be named, coded or otherwise made identifiable/identifiable. A counter may be included to assist the operator in remembering the number of biopsies taken. To further automate the biopsy, several of all of the cavities of the tissue storage container may be partially pre-filled with a preservative, such as concentrated formalin or another suitable preservative. In this way, the rinsing liquid sprayed into the rinsing chamber serves at least two purposes: (1) loading the tissue sample from the sample-containing device into a storage container, and (2) adjusting the concentration of the preservative in the storage container to a level suitable for storage of the tissue sample.

To facilitate tissue penetration of the sample-receiving device, the sample-receiving device may include or be formed as a cannula with a sharp distal tip. The cannula extends coaxially within the hollow needle.

An alternative embodiment of the aforementioned vacuum flush mechanism uses a paired syringe plunger system as an alternative to the syringe plunger system and the vacuum working fan. The vacuum flush mechanism includes pairs of syringe chambers, each with a plunger slidably disposed in the interior chamber of each chamber.

The first chamber functions as a vacuum supply unit and includes two openings, each of which is mounted with a check valve. A valve allows air to enter the interior cavity of the chamber when the plunger, which is enclosed in the chamber, is retracted. The valve is in fluid communication with the proximal end of the cutting cannula. When the plunger is retracted, air flows out of the hollow needle lumen and a vacuum is created. The vacuum communicates with the lumen of the hollow needle and into the lumen or tissue cavity of the sample-receiving device where it engages and draws tissue out through the lateral opening of the sample-receiving device and into the lumen of the container. Another valve allows air to escape as the plunger moves forward.

The vacuum feed plunger may be driven by a rack and pinion system or other linkage mechanism housed in the handle unit.

Other units include a pressurized liquid supply unit. It comprises a syringe-like chamber and a plunger movably arranged in said chamber and having two openings each provided with a one-way valve. A valve allows flushing fluid, such as saline, water, etc., to enter the cavity defined by the chamber when the plunger, which is enclosed in the chamber, is retracted. The valve is connected to a liquid supply by a sealed connection. The liquid supply may comprise a plastic container having relatively soft walls such that in response to retraction of the plunger, irrigation liquid is drawn from the liquid supply unit and into the interior cavity of the chamber. The walls of the plastic container collapse inwardly as the container empties, ensuring that no air enters the system. By subsequent forward movement of the plunger, flushing liquid is ejected from the lumen of the chamber through the outlet valve into the flushing chamber.

A pressurized liquid supply plunger is operatively connected to the driver unit and a suitable power transmission member or coupling mounted on, for example, the shaft of the plunger may provide rearward movement to the plunger. The forward movement of the plunger is preferably driven by a spring operatively connected to the shaft of the plunger. When the plunger shaft moves rearward, potential energy is stored in the spring. At a given point, the shaft is released and potential energy stored in the spring is released to move the plunger forward and eject flushing fluid from the chamber. At the end of the living tissue cycle, the plunger shaft is engaged again by the power transmission mechanism and a new cycle can be started.

The biopsy device of the invention may further comprise:

a first user operable firing mechanism for longitudinally moving the hollow needle and sample-receiving device in a distal direction to penetrate the living tissue at or near the tissue mass to be examined;

a second user operable firing mechanism for longitudinally moving the hollow needle in a distal direction from a first position in which the sample-receiving device protrudes from the distal end of the hollow needle to a second position in which the hollow needle substantially receives the cavity of the sample-receiving device, thereby severing the tissue sample from the remaining living tissue at the access location.

It will be appreciated that the first user operable firing mechanism is optional, i.e. the biopsy device may comprise only a second firing mechanism. The first firing mechanism may advantageously be incorporated into a separate module that may or may not be mounted to the device during assembly thereof.

The first firing mechanism is used to penetrate a tissue mass to be examined, such as a tumor, which penetration may be difficult to encircle the tissue of a living body due to, for example, stiffness or due to a loose bearing attachment of the tissue mass to be examined. The loose bearing connection may cause the piece of tissue to be examined to move under pressure from the tip of the biopsy needle and slide past the piece of tissue to be examined without penetrating it. It has been found that by firing the inner and outer needles substantially simultaneously, preferably at a relatively high speed, it is possible to contact and penetrate even loosely supported tissue masses. In the following, the substantially simultaneous firing of the outer needle and the sample-receiving device will be referred to as "double shot".

The biopsy device may include first and second user operable firing mechanism control systems configured such that only one of the firing mechanisms may be activated at a time. The control system may be based on an electronic control device that provides control signals to one or more motors and other components of the firing mechanism. To accelerate tissue acquisition, the control system may be configured to automatically activate the second firing mechanism after firing of the first firing mechanism, i.e., such that the tissue sample is automatically severed following penetration of the suspect tissue mass.

The first and second firing mechanisms may include respective energy storage and release mechanisms. The energy to be stored may be provided, for example, by an electrically driven motor. The energy release mechanism may be controlled to release the stored energy substantially simultaneously to fire the outer hollow needle and the sample-receiving device substantially simultaneously (double shot, first firing mechanism) or to fire the outer hollow needle separately ("single shot", second firing mechanism). The energy storage means may for example comprise a spring, such as a compression spring. Thus, the first firing mechanism may comprise a first compression spring, the second firing mechanism may comprise a second compression spring, and the device may further comprise at least one loading mechanism for loading the first and second springs and releasing the springs after loading thereof. The loading mechanism may include one or more elements for transferring movement of the one or more actuators to the spring. The drive may for example comprise at least one linear drive and/or at least one motor, the rotary movement of which may be converted into a linear movement of one or both compression springs. The conversion of such movement may be provided, for example, via a gear/rack drive or via abutment of a member protruding from the surface of a rotating wheel with a linearly movable member. For most applications, the force provided by each of the first and second springs may be 20-150 newtons, such as 40-80 newtons, such as approximately 50 newtons.

The first firing mechanism may be connected to a needle drive member that is secured to the hollow needle to transfer the firing force of a first spring or other energy storage device to the hollow needle. The first and second firing mechanisms, the hollow needle, the sample receiving device and the needle drive member are preferably all comprised in a disposable unit which is releasably connected to the handle unit. The first spring is preferably connectable to a transport device for moving the sample-receiving device in the hollow needle, and the first spring may also be connected to the needle drive element. Thus, the hollow needle and the sample receiving device may be moved longitudinally after release of the first firing mechanism.

A first powered element, such as a motor, may be provided for driving the transport device to move the sample receiving unit back and forth in the hollow needle. In order to minimize the resistance to the firing force provided by the first firing mechanism, the loading mechanism may be configured to decouple the transport device from the motor after loading of the first spring, the transport device preferably being movable together with the sample-receiving device in the hollow needle upon firing of the first firing mechanism. In one embodiment, the movement of the motor is transmitted via a gear drive to a delivery device comprising, for example, a bendable elongate element. During firing of the first firing mechanism, the gear driven gear that engages the delivery device may remain engaged with the delivery device to keep it stable. The disengagement of the conveyor from the motor can then take place at a position which is closer to the motor in the drive chain than the actual position of the engagement between the gear drive and the conveyor. The aforementioned stabilization is particularly useful in embodiments where the delivery device comprises a bendable elongate element.

The first and second firing mechanisms may include a common trigger member and a second powered drive member for moving the trigger member. The trigger element may for example comprise a linearly movable member or a rotatable member, such as a gear. The control system of the biopsy device may be configured such that the first firing mechanism may be loaded and fired during a first phase of movement of the trigger element and the second firing mechanism may be loaded and fired during a second phase of movement of the trigger element. For example, if the trigger element comprises a linearly movable member having a certain stroke, the first movement stage may correspond to a portion of the stroke and the second movement stage may correspond to a second portion of the stroke. Alternatively, if the triggering element comprises a rotatable element, the first movement phase may correspond to an initial angular rotation of, for example, 90 °, and the second movement phase may correspond to a subsequent angular rotation of, for example, another 90 °.

A single motor, such as an electric or pneumatic motor, may conveniently advance or drive the transport and the first and second firing mechanisms. Thus, it will be appreciated that first and second movement stages of the motor may be used to load the first and second firing mechanisms respectively, while another movement stage, for example another 170 ° rotation of the trigger element, may be used for movement of the sample containment device between the first extended position and the second retracted position.

It will thus be appreciated that the trigger element may be arranged relative to the firing mechanism and the delivery device such that movement thereof in a first direction causes firing of at least one of the first and second firing mechanisms, and such that further movement of the trigger element in the first direction causes movement of the delivery device to move the sample containment device from the first extended position to the second retracted position for ejection of the captured tissue sample. This may occur, for example, during a rotation of the triggering element of almost 360 °, comparing the example of the above-mentioned angular range accumulated to 350 °. Movement or rotation of the trigger element in a second direction, e.g., relative rotation to linear movement, may result in movement of the delivery device to move the sample containment device from the second retracted position to the first extended position for obtaining additional tissue samples and/or for firing additional double shots. Movement of the trigger element in the second direction may cause resetting of the first and/or second firing mechanisms to reset the mechanisms for subsequent cycles of double and/or single shots.

The control system of the biopsy device may comprise an electrically activated solenoid for moving the transfer member of the first firing mechanism into the path of movement of the trigger element. For example, the trigger element may comprise a rotatable wheel having an outwardly projecting element projecting from a surface thereof. When the solenoid has not caused the transfer member of the first firing mechanism to move into the path of movement of the trigger element, the projecting element moves past the first firing mechanism without activating it during movement of the trigger element. Thus, only the second firing mechanism will be activated. However, if the solenoid is activated, the outwardly projecting element engages the transfer member of the first firing mechanism and movement of the trigger element will load and fire the first firing mechanism before the second firing mechanism can be loaded and fired. It will be appreciated that the solenoid may alternatively be arranged to move the trigger element such that its path of movement coincides with the transfer member of the first firing mechanism.

In case the biopsy device is embodied as a hand held unit, the first and second firing mechanisms may advantageously form part of the hand held unit.

In one embodiment, a control system of the biopsy device is configured to operate the firing mechanism and the delivery device in a predetermined cycle. Such a cycle may for example comprise the following steps:

the bijecting may optionally be performed if the operator of the device has initiated the bijecting by providing a corresponding input to the control system, for example via an interface in the handheld unit;

activating a vacuum pump, optionally included in the device, to aspirate or sever tissue into the cavity of the sample containment device;

performing a single shot to sever the tissue sample and discontinuing vacuum aspiration before or after severing;

moving the sample containment device to a second retracted position;

ejecting the tissue sample from the sample containment device, for example by liquid flushing as described below;

returning the sample containment device to the first extended position;

the control system may, for example, be programmed or pre-programmed to implement other cycles, such as repeating the following steps a number of times:

performing single shot;

moving the sample containment device to a second retracted position;

ejecting a tissue sample from a sample containment device; and

the sample containment device is returned to the first extended position to obtain several tissue samples between separate severing (i.e., single shot) operations without user intervention.

The biopsy device may further comprise a control system for controlling the movement of the delivery device and stopping the sample containment device in the second retracted position. The second retracted position is generally the position of the sample-receiving device in which at least one severed tissue sample may be ejected from the cavity of the sample-receiving device. In order to make the task of staying the sample-receiving device in the correct position independent of the physician handling the device, the aforementioned control system may be configured to automatically stop the sample-receiving device in the second retracted position. In one embodiment, the control system comprises a sensor for detecting the position of the sample-receiving device and/or the cavity therein. For example, a photocell or electromechanical switch may be provided for providing a signal to the control system when the sample containment device is at or near its second retracted position. Alternatively, or in addition, the control system may be arranged to automatically detect the distance between the first extended position and the second retracted position.

Thus, it will be appreciated that the control system may allow the biopsy device to be operated automatically with different needles of different lengths, and that there is no configuration required by the user of the device in order to adapt the control system to a particular needle length. In case the hollow needle and the sample-receiving device are comprised in a disposable unit which is releasably connected to the handle unit of the device, it is easy to perform a replacement of the hollow needle with another different length. This exchange is further facilitated by the ability of the control system to stop the sample-receiving device at the second retracted position without requiring specific user input to adapt the control system to a specific needle length, and the biopsy device is more reliable with respect to the correct positioning of the sample-receiving device in the second retracted position.

The control system may, for example, be configured to automatically detect a distance between the first extended position and the second retracted position of the sample containment device after the disposable unit is attached to the handle unit. Thus, the control system may be configured to detect placement or replacement of the disposable unit in the handle unit, for example with a sensor integrated into the handle unit, and in response to such detection, to initiate the aforementioned detection of the distance between the two positions.

To accomplish this detection, the disposable unit may include an electronic memory and the handle unit may include an electronic interface for retrieving information stored in the electronic memory, the electronic interface being configured to communicate the information to the control system. It will be appreciated that the ability to communicate between the disposable unit and other elements of the biopsy device, such as the handle unit, constitutes a separate aspect of the present invention that may benefit from, but does not necessarily require, the presence of the other features disclosed herein. For example, the unit housing the control system may be a handheld unit or a non-handheld unit. The electronic memory may for example comprise a four terminal sequence of EEPROM, EPROM or three of ROM with terminal ground, Vdd, CLK and bidirectional data lines, as the sequence EEPROM ATMEL AT24C 01. The information stored in the electronic memory may for example represent the distance between the first extended position and the second retracted position of the sample-receiving device, the length of the outer hollow needle and/or the length of the bendable elongated element.

Alternatively or in addition to the electronic memory, the control system may include a sensor for detecting when the sample-receiving device reaches a proximal limit of its range of movement, which is preferably predefined. The proximal limit may for example be the second retracted position or a position at a predetermined distance from the second retracted position, which is independent of the length of the needle, i.e. not changed when the disposable unit is replaced. The distal limit of the sample-receiving device may be, for example, the first extended position. The sensor for detecting that the sample-receiving device has reached the proximal limit may, for example, detect a change in a physical characteristic, such as a change in current or voltage, a magnetic field, or a change in an acoustic, optical or mechanical parameter. The sensor may comprise a hall sensor, a potentiometer, a current measuring device, or a mechanical switch.

For example, the transport device may comprise a position or movement signal generator for generating a position or movement signal to the control system indicative of the longitudinal position or movement of the sample-receiving device. In this embodiment, the control system is configured such that, after mounting the hollow needle and the sample-receiving device on the handle unit:

actuating the transport device to retract the sample containment device to its proximal limit and recording a position or movement signal in the proximal limit; and

the recorded position signal is used as a position reference point for subsequently arresting the sample containment device in the second retracted position after tissue acquisition. Preferably, the drive force is transmitted from a motor to the conveyor, the motor being controlled by a microcontroller, the microcontroller receiving as input a position or movement signal, the output of the motor being generated in dependence on the input.

In order to obtain the desired position control of the sample-receiving device, the control system may comprise at least one pulse-generating device, such as a hall element, for generating a pulse in dependence on the movement or position of the sample-receiving device. The proximal limit of the sample-receiving device may be defined by a mechanical stop of the sample-receiving device that causes a change in the generation of the pulse when the sample-receiving device contacts the mechanical stop.

In case the conveying device is subjected to a driving force from an electric motor, the sensor, which is a spare or supplement to the hall element, may comprise a current or voltage sensor for measuring the motor current through the motor. Thus, the risk of the motor current exceeding a predetermined threshold may be used as an indicator that the sample-receiving device has reached its proximal limit, i.e. a mechanical stop.

The aforementioned position signal generator may include a potentiometer provided, for example, on a drive shaft for transmitting the driving force to the conveying device.

After mounting the disposable unit to the handle unit, the control system may perform an initial run or calibration cycle to move the sample containment device to its distal and/or proximal limits to determine the length of the needle, the distance between the first extended position and the second retracted position of the sample containment device, or any other value, which may enable the control system to stop the sample containment device at the second retracted position. The initial operation preferably returns the sample containment device to a default position, such as the first extended position.

The handle unit, the hollow needle, the sample receiving device, the delivery device and the control system, and all other optional components of the present biopsy device may be comprised in a hand-held unit.

In a second independent aspect, the present invention provides a disposable unit for a biopsy device for taking at least one tissue sample from a living organism, the disposable unit comprising:

a hollow needle with a distal portion adapted for introduction into a living body;

a cutting mechanism for severing the at least one tissue sample;

a sample-receiving device with a cavity for receiving the at least one severed tissue sample, the sample-receiving device being receivable in the hollow needle and movable therein;

a transport device for moving the sample containment device within the hollow needle, the transport device comprising a bendable elongate element;

an interface for connecting the disposable unit to an external unit located outside the disposable unit, the external unit comprising a drive unit with a power source, the interface being adapted to transmit the driving force of the drive unit to the delivery device. The external unit may for example comprise a handle unit as described above.

As will be clear from the previous part of the description, the disposable unit may further comprise a winding device for winding the bendable elongated element.

In a third independent aspect, the present invention provides a biopsy device for obtaining at least one tissue sample from a living organism, the device comprising:

a hollow needle with a distal portion adapted for introduction into a living body and a first orientation means;

a cutting mechanism for severing a tissue sample;

a sample receiving means having a cavity for receiving a severed tissue sample and a second orientation means, the sample receiving means being receivable in the hollow needle and movable therein between a first extended position and a second retracted position;

a transport device for moving the sample receiving device in the hollow needle;

wherein the first and second orientation means act in concert to orient the sample-receiving device in a plane perpendicular to the axis of movement of the sample-receiving device.

Such orientation means are described in more detail above in connection with the first aspect of the invention.

Drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a general illustration of a biopsy device;

FIG. 2 is an exploded view of an embodiment of the biopsy device;

FIGS. 3-6 illustrate a fluid flushing system (liquidflushing system) in the biopsy device;

FIGS. 7-25 illustrate a first firing mechanism (firing mechanism) for firing an outer needle and a sample-receiving device of a biopsy device substantially simultaneously;

FIG. 26 illustrates a lockout mechanism for the gears of the firing mechanism;

27-31 illustrate a second firing mechanism for firing only the outer needle;

FIGS. 32-35 illustrate a mechanism for moving the sample receiving device in the outer needle;

FIG. 36 is an exploded view of the gear carrier (gear chassis) of the biopsy device;

FIGS. 37 and 38 illustrate the cycle of the trigger wheels (trigger wheels) of the first and second firing mechanisms;

fig. 39 and 40 illustrate an embodiment of a system for determining the distance between two locations of a sample-receiving device.

Detailed Description

FIG. 1 shows a simplified schematic illustration of a biopsy device having features of the present invention. The device comprises a biopsy needle 108 comprising a hollow needle 50 in which a longitudinally displaceable tissue sample receiving means 52 is arranged. The sample-receiving device includes a tapered distal tip 54 and a cavity or canoe 56 for receiving a tissue sample. The sample containment device includes a vacuum port 58 in fluid communication with the canoe 56 to allow tissue to be drawn into the canoe once the canoe is placed in a test site within a living being. The vacuum is provided by a vacuum pump (not shown). The distal portion of the hollow needle 50 provides a circumferential cutting edge 60 for severing tissue samples drawn into the canoe 56. The device includes a spring-loaded firing mechanism, schematically illustrated in fig. 1 by a coil spring 62, which is arranged to move the hollow needle 50 in a forward (distal) direction to sever tissue samples drawn into the canoe 56. At the proximal end of the device, a sample flush chamber 109 is provided from which the severed tissue sample in the canoe 56 can be ejected into the sample container 64. More particularly, the sample containment device 52 with the canoe 56 is retracted from a first extended position, as shown in FIG. 1, in which the canoe 56 protrudes from the distal end of the hollow needle 50, to a second retracted position, in which the canoe 56 is aligned with the upper and lower openings in the sample washing chamber 109. A flushing liquid, such as saline, is used to eject the tissue sample from the canoe 56 into the sample container 64, the flushing liquid being delivered from the liquid container 114 through the hollow liquid delivery member or tube 116 with the aid of a peristaltic pump 118.

To move the sample containment device 52 with the canoe 56 between the first and second retracted positions shown in fig. 1, a transport device is provided that includes a bendable elongate element 66 in the form of a bendable rod or wire. The lower surface of the bendable rod or wire is toothed so that it can engage a rotatable gear or pinion 68 arranged to move the rod or wire 66 longitudinally, thereby moving the sample containment device 52 back and forth within the hollow needle 50. A motor 70 is provided for applying a driving force to the gear or pinion 68 and a guide wheel 72 is provided for stabilizing the bendable flexible rod or wire 66. To control the rod or wire 66 when the canoe 56 is retracted for tissue sample ejection, a winding device 74 is provided for the rod or wire 66.

The biopsy device schematically illustrated in fig. 1 operates as follows: initially, the sample-receiving device 52 and the hollow needle 50 are arranged such that the sample-receiving chamber or canoe 56 is covered by the hollow needle 50, i.e. such that the outer surface of the conical distal tip 54 of the sample-receiving device 52 forms a conical distal extension of the outer surface of the hollow needle 50. In this configuration, the needle 108 is caused to penetrate the bodily tissue of the patient, such as by being manually inserted into the patient by a surgeon. Once the needle has penetrated the tissue mass to be examined, e.g. a tumor, the hollow needle 50 is retracted to the position shown in fig. 1, compressing the spring 62 and thus loading the firing mechanism of the hollow needle. A vacuum is then drawn through the vacuum port 58 to draw the tissue into the canoe 56. The firing mechanism of the hollow needle 50 is then released and the hollow needle 50 is fired forward, i.e. in the distal direction, to its initial position covering the canoe 56. This forward firing causes the circumferential cutting edge 60 of the hollow needle to sever the tissue sample in the canoe 56. The sample containment device 52 is then retracted to its second retracted position, in which the canoe 56 is aligned with the sample flushing chamber. Movement of the sample containment device is caused by rotation of a gear 68 in a clockwise direction, the gear 68 engaging a flexible rod or wire 66 which in turn is connected to the sample containment device 52. In the retracted position of the canoe 56, a flow of rinsing liquid is forced through the sample rinsing lumen to eject the tissue sample from the canoe into the sample container 64. Once the spray has been completed, the flow of the flushing liquid is interrupted and the gear 68 is rotated counterclockwise to cause the flexible rod or wire 66 to move in the distal direction, thereby urging the sample containment device 52 rearwardly to its first extended position. The above-described cycle including tissue sample acquisition and ejection may then be repeated one or more times to obtain several tissue samples without retracting the hollow outer needle 50 from the biopsy site of the living body.

It will be appreciated that the elements provided at the proximal end of the biopsy device shown in fig. 1, i.e. the firing mechanism including the spring 62, the gear or pinion 68, the motor 70, the steering wheel 72, the winding device 74, optionally the sample container 64, the sample rinsing lumen 109, the liquid container 114, the tube 116, the pump 118 and the vacuum pump (not shown) may be conveniently integrated into a handle unit as set forth in the description of the embodiments of the invention attached below.

FIG. 2 is an exploded view of an embodiment of the biopsy device according to the invention. The device comprises left and right cover parts 100, 102, as well as a carriage unit 104 arranged between the cover parts and a disposable unit 106 comprising a biopsy needle 108 and a sample flushing chamber 109. A first firing mechanism 110 is also provided for firing the biopsy needle in a first mode as explained in detail below. The first firing mechanism 110 forms an integrated unit that is optional in the present biopsy device. The carriage unit 104 includes a second firing mechanism 112 for firing the biopsy needle in a second mode as explained in detail below. The right cap portion 102 forms a flushing system that houses a fluid delivery to the disposable unit 106 to eject the biopsy sample from the sample flushing chamber 109. The irrigation system includes a liquid container 114 to which is connected a hollow liquid delivery member or tube 116 defining an elbow portion 117. To deliver liquid from the container 114 to the sample rinsing chamber 109 through the tube 116, a peristaltic pump 118 is provided for engaging the elbow portion 117 of the tube 116. When mounted on right cover portion 102, elbow portion 117 is held tightly to peristaltic pump 118 by a pair of jaws 120, 122. When assembled, the left and right cover portions 100, 102, gear carrier 104 and irrigation system 114 and 122 form a handle unit 105 to which the disposable unit 106 is releasably secured. A locking handle 124 comprising an inner bushing 126 is provided to releasably secure the disposable unit 106 to the handle unit 105.

The liquid flushing system is further disclosed in fig. 3-6. On the outer surface of right cap portion 102, notches 128, 130 (see FIG. 2) and 132 are provided for receiving liquid container 114, peristaltic pump 118 and tube 116, respectively. A pair of projections 134 are provided at upper and lower edge portions of the notch 128 to secure the container in the notch 128. The fluid reservoir 114 and tube 116 are disposable elements that may be replaced on a regular basis by the operator of the biopsy device. Replacement of these elements does not require disassembly of the pump 118, which normally remains attached to the right cap portion 102 during replacement of the container 114 and tube 116. In fig. 3, jaws 120, 122 are open and container 114 and tube 116 are easily placed into corresponding notches 128, 130, and 132 formed in right cap portion 102. Fig. 4 illustrates the container 1114 and tube 116 housed in the right cap portion, with the elbow portion 117 positioned substantially around the circumference of the pump 118. In fig. 4 the jaws 120 and 122 are open, while in fig. 5 the jaws are partly pivoted to their closed position, and in fig. 6 the jaws 120, 122 are fully pivoted to their closed position, wherein they keep the elbow portion 117 in close contact with the pump 118. When the container 114 and tube 116 are so mounted in the right cap 102, the free end of the tube 116 is connected to a conduit in the disposable unit 106 (compare fig. 2) for providing a fluid path from the container 114 to the sample rinse chamber 109 of the disposable unit.

The first firing mechanism 110, generally illustrated in FIG. 2, will now be further described with reference to the exploded view of FIG. 7. The firing mechanism 110 is configured to fire the sample containment device 52 and the outer needle 50 of the biopsy device substantially simultaneously. Referring back to fig. 1, sample-receiving device 52 and outer hollow needle 50 may then be fired substantially simultaneously. Such simultaneous firing may be useful for penetrating a tissue mass to be examined, such as a tumor, which may be difficult due to, for example, stiffness or due to the tissue mass to be examined being loosely bearing against surrounding tissue attached to the living body. The loose bearing connection may cause the piece of tissue to be examined to move due to pressure from the tip of the biopsy needle and slide past the piece of tissue to be examined without penetrating it. It has been found that by firing the inner and outer needles at relatively high speeds substantially simultaneously, it is possible to contact and penetrate even loosely supported tissue masses. In the following, the feature of substantially simultaneous firing comprising the outer needle and the sample receiving device will be referred to as "double shot".

The method of operation of the dual fire firing mechanism 110 of FIG. 7 will now be described with reference to FIGS. 8-26. The mechanism includes a spindle 136 extending longitudinally through and parallel to the longitudinal axis of compression spring 138 and through slide 140. A double-shot frame 142 supports the spring 138 and the runner 140 between opposing wall regions 144, 146. This is also visible in fig. 2, and it is also clear from fig. 2 that the free end 141 of the runner 140 extends through the opening 107 into the disposable unit 106, which free end 141 engages a yoke 182 (compare fig. 13) which in turn engages a needle driver 111 fixed to the outer surface of the hollow needle 50. Below the spring 138, a solenoid 148 extends through the frame, on the opposite side of the frame, through a nut 150, compressing a spring 152, and into a solenoid retainer 154. The solenoid holder engages the bijective lever 156 via a solenoid connector shaft 158 that extends through the lever 156 and into the solenoid holder 154. An upper pivot pin 160 of the lever 156 is pivotally supported relative to the frame 142 and extends through a frame projection 162 so that the solenoid 148 may pivot the lever 156 about the pivot pin 160. The double-shot mechanism 110 also includes a slide rail 164, a sliding jaw 166, a spring jaw 168, and a transfer member (impart) 170. Two passages are provided in the transfer member 170, a first passage 172 for the solenoid connector shaft 158 and a second passage 174 for the main shaft 136. A transfer member return spring 173 is disposed between the transfer member 170 and the distal facing surface 143 of the runner 140.

Fig. 8 includes a configuration of the biopsy device that facilitates the double firing, i.e. the substantially simultaneous firing of the outer hollow needle 50 and the sample receiving means 52. The double fire firing mechanism 110, illustrated in an exploded view in FIG. 7, is assembled and mounted to a carriage unit 104 (compare FIG. 2), which carriage unit 104 also supports the disposable unit 106. In fig. 8, the carrier unit is only partially shown for clarity. A motor driven toothed trigger wheel 176 is provided for compressing the compression spring 138 (compare fig. 7), as explained below with reference to fig. 11-17.

As shown in the end views of fig. 9 and 10, the lever 156 has two positions, an inclined position as shown in fig. 9, and a vertical position as shown in fig. 10. The lever 156 is normally biased toward the tilted position of fig. 9 by a compression spring 152, which compression spring 152 is omitted from fig. 9 and 10 for clarity. In case the operator of the biopsy device tries to fire the outer hollow needle 50 and the sample receiving device substantially simultaneously, i.e. to perform a double shot, a suitable input is provided to the electronic control system of the biopsy device, e.g. via a keyboard on the outer surface of the covers 100, 102 (compare fig. 2). This double firing action is initiated by the actuation of the solenoid 148 causing the lever 156 to pivot about the upper pivot pin 160 so that the lever pivots from the inclined position of fig. 9 to the vertical position of fig. 10.

Subsequently, as shown in FIG. 11, the trigger wheel 176 rotates in the direction of arrow 178. During the course of this rotation, the first carrier element 180 protruding from the surface of the trigger wheel 176 contacts the transmission member 170, such that the transmission member 170 moves in a distal direction along the solenoid connector shaft 158. The stroke of the transmission member 170 is defined by the side wall of the lever. Thus, when the transfer member 170 has reached the position shown in fig. 12, it cannot move further in the distal direction. As will be described in detail below, movement of the transfer member 170 causes the sled 140 (compare fig. 7), the needle driver 111 (compare fig. 2 and 8), and the outer hollow needle 50 and sample containment device 52 to move in a distal direction while the compression spring 138 is compressed, the compressed compression spring 138 being shown in fig. 12 and omitted from fig. 11. The firing mechanism for firing the inner and outer needles substantially simultaneously is now loaded.

The loaded firing mechanism is illustrated in perspective view in FIG. 13. The compression spring 138 is loaded and the yoke 182 has moved proximally, i.e., the retracted position shown in fig. 13. The yoke 182 is connected to the runner 140 via a pressure pin 202 (compare fig. 18) engaging a notch formed in the free end 141 of the runner 140, and the yoke 182 engages the needle driver 111, so that rotation of the trigger wheel 176 in the direction of arrow 178 (compare fig. 11) causes the yoke 182 and thus the needle driver 111 and outer needle 50 to move closer together. The outer hollow needle can then be moved from its first extended position shown in figure 8 to its second retracted position of figure 13. As further illustrated in fig. 13, the yoke 182 defines a recess 184 in which is received a slider 186 having an outwardly projecting center piece 188. During retraction of the yoke 182, i.e., loading of the dual fire firing mechanism, the central member 188 is forced downwardly to engage the bendable elongate element 66, which is secured to the sample containment device 52. As the centerpiece 188 engages an engagement member (not shown) during the proximal movement of the carriage, the engagement member may, for example, form a portion of the housing (not shown) resulting in the desired downward movement of the centerpiece 188. Thus, when the yoke 182 moves in the proximal direction, the central piece 188 also moves proximally, and the pliable element 66 and the sample containment device 52 move in unison with the central piece 188 of the slide 186.

In the illustrated embodiment, the bendable elements 66 comprise a toothed flexible wire or rack that is driven by a forward gear 190 (compare fig. 19) that engages the teeth of the toothed flexible wire 66. Rotation of the gear 190 may then cause the bendable elongate element 66 and the sample containment device 52 to move away from or closer together depending on the direction of rotation of the gear 190. The support roller 192 is provided to stabilize the flexible wire 66, i.e., to prevent it from flexing upward as it is moved in the distal direction to push the sample containment device 52 in the distal direction.

In one embodiment, bendable elongate element 66 is made of nylon 6-6. The bendable elongated element may have a substantially circular cross-section with flat upper and lower surfaces, such that the element forms a wire with flat upper and lower surfaces and curved left and right surfaces. For example, the element may be approximately 1.2 mm in diameter and approximately 0.85 mm in cross-sectional dimension between the flat upper and lower surfaces. In one embodiment, the outer needle 50 has an outer diameter of approximately 2.1 millimeters and an inner diameter of approximately 1.8 millimeters, the outer diameter of the sample collection device 52 is approximately 1.8 millimeters in this embodiment, and the inner diameter of the sample containment device is 1.5 millimeters.

When the transfer member 170 has moved to its proximal limit as shown in fig. 12 and 13, a spring biased release 194 defining a cam 196 engages a distal facing edge on the lower surface of the slide 140 as shown in fig. 14. The release 194 is not visible in fig. 11-13 because it is hidden behind the lever 156 and trigger wheel 176. The release 194 is rotatably spring biased so that the cam 196 slides along the lower surface of the slide 140 until the transfer member 170 and slide 140 have reached the proximal limit.

At this stage, rotation of the trigger wheel 176 is interrupted and the solenoid 148 is deactivated, thereby compressing the spring 152 (compare fig. 7) to return the lever 156 to the tilted position shown in fig. 9. Thus, the first carrier element 180 (compare fig. 11 and 12) loosely contacts the transfer member 170, and the transfer member return spring 173 forces the transfer member 170 back to its initial position, i.e., its distal limit end, as shown in fig. 15. However, since release 194 engages slide 140, as shown in fig. 14, spring 138 remains loaded, thus preventing slide 140, yoke 182, needle driver 111, outer needle 50, slider 186, toothed flexible wire 66, and sample containment device 52 from moving in the distal direction. The firing mechanism is now ready to fire, i.e. release the spring 138, to fire the outer needle 50 and the sample acquiring device 52 substantially simultaneously.

The side elevational views of fig. 16 and 17 show the device from a side opposite to that viewed in fig. 11-15. The distal end of the device is then to the left in fig. 16 and 17. Assume now that the trigger wheel 176 rotates in the direction of arrow 178 (compare fig. 11), whereupon the trigger wheel rotates counterclockwise in fig. 16 and 17. Now, the second carriage element 200, which is attached to the trigger wheel 187, contacts the proximal portion of the release 194, thus causing the release to rotate clockwise in fig. 16 and 17 (counterclockwise in fig. 13). As a result of this rotation, cam 196 of release member 194 moves downward so that its abutment on runner 140 is released. Thus, the compression spring 138 is released, as shown in FIG. 17, and the double shot is fired.

In one embodiment of the present invention, the compression spring 138 for the double shot compresses 20-25 millimeters during loading of the double shot mechanism, corresponding to 20-25 millimeters of movement of the needle 50 and sample holder, as described above. Thus, in this embodiment, the needle 50 and sample-receiving device 52 have been moved in the distal direction between the two positions shown in FIGS. 16 and 17, respectively, by 20-25 mm.

The disposable unit 106 incorporating several of the elements described above in connection with the duplex firing mechanism will now be further described with reference to FIGS. 19-26. The disposable unit 106 includes a drive gear 204 of the toothed flexible wire 66. A cross-shaped drive shaft 206 projects from a side surface of the drive gear 204, the cross-shaped drive shaft 206 engaging a correspondingly shaped member in the gear carrier 104 (compare fig. 2). The carrier 104 includes a motor for providing a driving force to the cross-shaped drive shaft 206. The drive gear 204 is arranged to drive a first intermediate gear 208 which in turn is arranged to drive a second intermediate gear 209 which drives the forward gear 190, the forward gear being arranged coaxially with the second intermediate gear 209 in a plane adjacent to that of the second intermediate gear, so that the appropriate meshing portions are provided at the opposed surfaces of the second intermediate gear 209 and the forward gear 190. These meshing portions provide a releasable interconnection such that the second intermediate gear 209 is disengaged from the advancing gear 190 prior to firing the double fire. This disengagement is caused by an arm 191 forming part of the yoke 182, which arm thus moves with the carriage. When the double shot has been fired, the second gear 209 and the advancement gear 190 return to intermesh. The proximal end region 67 of the toothed flexible wire 66 widens and includes a notch 69 for engagement by a flange portion 189 of the central member 188 of the slider 186. The housing element 210 shown in fig. 18 houses a spiral wound groove for housing the toothed flexible wire 66 when the sample containment device 52 is retracted to its second retracted position in which the canoe 56 is aligned with the flush chamber 109 (compare fig. 2).

In fig. 20 and 21, the central member 188 of the slider 186 is lifted out of engagement with the widened proximal portion 67 of the toothed flexible wire 66. In this mutual position of the elements, the toothed flexible wire 66 can be moved by providing a driving force to the cross-shaped driving shaft 206 by means of a suitable motor (not shown), which can advantageously be integrated into the gear carrier 104. In fig. 22 and 23, the carriage 182 has been partially retracted, which causes the centerpiece 188 to engage the widened proximal portion 67 of the toothed flexible wire 66, as described above with reference to fig. 9-13. Upon further retraction of the yoke 182, the first carriage arm 183 engages the notch 113 in the needle driver 111 and the second carriage arm 187 engages the notch 185 in the slider 186, also comparing the top views of fig. 24 and 25.

After the center piece 188 is engaged with the widened portion 67 of the toothed flexible wire, but before retraction of the needle driver 111 and the toothed flexible wire 66 for loading the duplex firing mechanism (compare the above description of FIGS. 8-17), the second intermediate gear 209 (compare the above description of FIG. 19) is disengaged from the advancing gear 190, as shown in FIGS. 24 and 25, the second intermediate gear 209 engages the advancing gear 190 of FIG. 24 and is disengaged in FIG. 25. Thus, the flexible toothed-wire 66 drive gear mechanism does not provide resistance to the loading and release of the dual fire firing mechanism. In an alternative embodiment, the advancement gear 190 remains engaged with the wire 66 during loading and firing in order to stabilize, i.e., prevent flexing, the wire 66. In this embodiment, the first intermediate gear 208 (compare fig. 20-23) may be advantageously decoupled from the forward gear 190 to reduce drag.

Fig. 25 and 26 generally depict a locking mechanism 220 for locking the drive gear 204 when the loading needle 50 is used for a single shot, as compared to the description of fig. 27-31 below. As will be appreciated, during a single shot, only the outer needle 50 is retracted and fired, and the position of the bendable elongate element 66 and the sample containment device 52 is locked or fixed due to the locking mechanism 220 engaging the cross-shaped drive shaft 206.

27-31, the second firing mechanism causes the outer needle 50 to be fired in a distal direction with its distal circumferential cutting edge 60 (compare FIG. 1) to cut the living tissue in the canoe 56. It will be appreciated that only the outer needle 50 is fired and the sample containment device 52 remains unaffected by the second firing mechanism 112. This firing of the outer needle 50 will be referred to below as "single shot". The trigger wheel 176 described above with reference to the double shot is also used in the single shot. In fig. 27, the trigger wheel 176 is in the same position as described in fig. 11. If the solenoid 148 is not activated and the bijective lever 156 is in the position of fig. 9, then rotation of the trigger wheel 176 in the direction of arrow 178 (compare fig. 11 and 27) does not cause the first carrier element 180 to contact the transfer member 170 (compare fig. 11) since the transfer member 170 is not in the plane of the carrier element 180. As a result, the first firing mechanism, i.e., the firing mechanism for the double shot, is not loaded. Thus, the trigger wheel 176 is free to rotate to the position of FIG. 28. Alternatively, if the solenoid 148 is activated and the bijection lever 156 is thus in the position of FIG. 10, rotation of the trigger wheel from the position of FIG. 27 to the position of FIG. 28 loads the bijection firing mechanism, as described with reference to FIGS. 10-17. Once the trigger wheel has reached the position of FIG. 28, and the duplex firing mechanism has been selectively loaded and fired, a third carriage element 300 projecting from the side surface of the trigger wheel 176 opposite the surface visible in FIG. 28 contacts a vertical transfer cam 302 attached to a trigger arm 304, which arm 304 is pivotally attached to the handle unit 105 at a pivot 306 (compare FIG. 2). At its upper end, trigger arm 304 forms a fork 308 engaging a transmission element 310, the proximal end of which abuts against the distal end of compression spring 62 and the distal end of which is connected to needle driver 111 via a pivotally mounted element 312.

The element 312 is pivotally mounted to a sliding support member 314 secured to the compression spring 62 and is spring biased upwardly to the inclined position shown in figures 27 and 28. The sliding support member 314 is connected to the trigger arm 304 via a connector 313 integral with the transmission element 310. When the double fire firing mechanism is to be loaded as described above with reference to fig. 7-26, member 312 remains in a substantially untilted position (not shown) to allow needle driver 111 to slide over the upper surface of member 312, and yoke 182 forces member 312 to its untilted position (compare, e.g., fig. 13).

After further rotation of the trigger wheel 176, the trigger arm 304 rotates about its pivot 306 due to the third carrier element 300 being transferred to the transfer cam 302 of the trigger arm 304, compare fig. 29. As a result, the compression spring 62 is compressed because the proximal end of the spring is properly supported. It will be appreciated that in the position of fig. 29, the outer needle 50 has been retracted so that the canoe 56 (compare fig. 1) of the sample containment device 52 has its distal end exposed to the distal portion of the outer needle 50. The position of fig. 29 thus corresponds to the position of fig. 1. At this location, a vacuum is drawn on the canoe 56 through the vacuum port 58 to draw the living tissue into the canoe 56. In fig. 30, the trigger wheel 176 has been further rotated to a position where the third carrier element 300 releases its engagement with the transfer cam 302 of the trigger arm 304 and thus unloads the compression spring 62, thereby releasing and firing (i.e., firing) the needle driver 111 forward, i.e., in a distal direction. The circumferential cutting edge 60 of the outer needle 50 thus severs the tissue (compare fig. 1) drawn into the canoe 56 so that the now severed tissue sample is contained within the canoe 56.

The single fire firing mechanism 112 is further illustrated in the exploded view of FIG. 31. The support shaft 316 extends through the compression spring 62 and is supported at its proximal end by a bushing 318 and a lock washer 320. The distal end of the support shaft 316 extends through the sliding support member 314, where it is supported by a pair of bushings 322. A pivot pin 315 is provided for the pivotable element 312. To ensure that trigger arm 304 is biased in the proximal direction, biasing mechanism 324 is mounted to trigger arm 304 via spring element 326, one end of which is secured in an engagement recess 328 provided on trigger arm 304. The other opposite end of the spring element 326 is secured to a door element 330 forming the transfer cam 302 (compare fig. 27-29). A compression spring 336 is provided for biasing pivotable element 312 toward an inclined position in which it is in contact with the proximal surface of needle driver 111 (compare fig. 27-30).

As described above with reference to fig. 27-31, rotation of the trigger wheel 176 causes the loading and firing of the single shot firing mechanism for severing the biopsy samples presently collected in the canoe 56 of the sample containment device 52 (compare fig. 1). Further rotation of the trigger wheel 176 causes movement of the bendable elongate member 66 in the proximal direction (compare fig. 1 and 19-23) to move the canoe 56 from its first extended position, in which it is received in the distal portion of the hollow needle 50, to its second retracted position, in which it is aligned with the irrigation lumen 109 (compare fig. 27-30, for example) for irrigating a spray of a biopsy sample with a liquid. This movement of the bendable elongate element 66 will now be further described with reference to fig. 32-36 which show the drive wheel 340 which forms the toothed arcuate portion 342 and the connecting portion 344. The free end of the link portion 344 is pivotally mounted to a roller 346 that slides in a curved track 348 formed in the carrier plate 350. The drive wheel 340 is rotatably supported at a center point 352 of the toothed arc 231. It will be appreciated from fig. 36 that the drive wheel 340 is connected to the trigger wheel 176 via a rotatable support at 352 where the drive wheel 340 is connected to a cam washer 354 forming a cutout 356 for engagement with the reduced diameter portion 347 of the roller 346. The cam washer 354 engages a circular member 358 that is secured to the trigger wheel 176. During rotation of the trigger wheel 176 from the initial position shown in fig. 11 to the position shown in fig. 30, the cutouts 356 disengage from the rollers 346 and thus the drive wheel 340 does not rotate. Upon further rotation of the trigger wheel 176, the cutout 356 of the cam washer 354 engages the roller 346, thereby forcing the free end of the connecting portion 344 of the drive wheel 340 downwardly in the curvilinear track 348. This in turn causes the drive wheel 340 to rotate about its rotatable support 352 so that the drive wheel 340 rotates from the position of figure 32 to the position of figure 34.

During rotation of the drive wheel 340 as described above, the toothed arcuate portion 342 of the drive wheel 340 engages a gear assembly not shown in fig. 32-34. The gear assembly, partially visible in fig. 36, includes a first gear 360 engaged by the toothed arcuate portion 342 of the drive wheel. The first gear 360 drives a second gear 362. The shaft 364 of the first gear 360 is mounted in the first sleeve 366, and the shaft 368 of the second gear 362 extends through a cross-shaped reinforcing member 369 and engages a connector 370 that provides a drive force transmitting interconnection to the drive gear 204 included in the disposable unit 106 (compare fig. 2 and 8). The disposable unit 206 also houses the bendable elongate element 66 for moving the sample-receiving device 52 (fig. 2), the flush chamber 109 and the winding device 74 (fig. 35) for winding the bendable elongate element 66 in the hollow needle 50. The drive gear 204, which is omitted from fig. 35 so as not to cover the winding device 74, drives the intermediate gear 208 and the forward gear 190, which in turn engages the teeth of the bendable elongate element 66. When the bendable elongate element 66 is moved in the proximal direction to retract the sample containment device for ejecting the harvested tissue sample, the bendable elongate element is wound into a winding device 74 forming a spiral shape, which allows the bendable elongate element 66 to be wound and unwound in a controlled manner.

The carrier 104 (compare fig. 2) includes the other elements shown in fig. 36. A drive motor 372 is provided for driving the trigger wheel 176 via a gear drive 374. Another motor 376 is provided for driving the peristaltic pump 118 (compare fig. 2-6) that ejects the sample by liquid flushing via the spindle 377 and gears 378 and 379. A guide bushing 380 is provided for the connector 370 to accommodate the disposable unit 106 in the handle unit 105 (compare 2). A vacuum pump 382 is provided for generating a vacuum suction to draw the living tissue into the canoe 56 of the sample containment device 52 (compare fig. 1 and 2), the vacuum pump 382 being in fluid communication with the canoe 56 via suitable tubing (not shown) and the vacuum port 58.

The cycle of the trigger wheel 176 for double and single shots described above with reference to figures 9-17 and 27-35 respectively is illustrated schematically in figures 37 and 38. Fig. 37 shows a movement cycle of the trigger wheel described with reference to fig. 28-34. From the position of fig. 28, the trigger wheel rotates approximately 290 to the position of fig. 34. The compression spring 62 is compressed during a first stage of rotation S-1, which corresponds to rotation of the trigger wheel 176 from the position of FIG. 28 to the position of FIG. 29. At S-2, the third carrier element 300 loosely contacts the vertical transfer cam 302, thereby unloading the spring 62. Now, the trigger wheel 176 has rotated the cam washer 354 to a position where the cutouts 356 engage the rollers 346. During a subsequent stage S-3 of rotation, the trigger wheel 176 is further rotated to rotate the drive wheel 340 from the position of fig. 32 to the position of fig. 34 to draw the sample containment device 52 rearwardly to its second retracted position in which the canoe 56 is aligned with the flush chamber 109 for ejecting the severed tissue samples collected in the canoe 56. The rotation of the trigger wheel 176 is now reversed as indicated by the black arrow in fig. 37. During the reverse rotation stage indicated by S-4 in fig. 37, trigger wheel 176 moves drive wheel 340 from the position of fig. 34 back to the position of fig. 32, thereby moving sample holder 52 to the distal portion of outer needle 50, i.e., the first extended position of the sample holder. In S-5, the sample holder 52 is now in its distal limit position and the cutout 356 of the cam washer 354 (compare FIG. 36) is disengaged from the roller 346. The final stage S-6 of the reverse rotation of the trigger wheel 176 is idle, wherein the trigger wheel 176 moves from a position substantially equal to FIG. 40 to the position of FIG. 28. Immediately prior to the termination of this S-6 rotation, the third carrier element 300 contacts and passes the transfer cam 302, which is biased in the proximal direction by the spring element 326 (compare fig. 31). The above cycle can now be repeated if further tissue samples are to be severed.

In fig. 38, the rotational phase of the trigger wheel 176 that results in the double shot described above with reference to fig. 9-17 is superimposed on the rotational phase shown in fig. 37 as S-1-S-6. During the first rotational phase D-1, the trigger wheel 176 rotates from the position of FIG. 11 to the position of FIG. 12 to compress the compression spring 138 (compare, for example, FIG. 12). After a further rotation D-2, the compression spring 138 unloads to fire the outer needle 50 and the sample acquiring device 52 substantially simultaneously, i.e. to move the trigger wheel from the position of fig. 16 to the position of fig. 17. The S-1-S-6 rotation phase is now performed as described above with reference to fig. 37. During the final reverse rotation phase D-3, the firing wheel 176 rotates from a position slightly upstream of the position shown in FIG. 12 (the counterclockwise rotating firing wheel in FIG. 12) to the position of FIG. 11. Since the solenoid 148 (compare fig. 9 and 10) is not activated and the bijective lever 156 is biased to its tilted position of fig. 9, the transfer member 170 is not in the plane of the first carrier element 180 (compare fig. 11 and 12) and the carrier element 180 is free to pass to the position of fig. 11 without contacting the transfer member 170.

In one embodiment of the invention, the control system of the biopsy device is configured such that the single-shot procedure is automatically sequenced after the double-shot procedure. In other embodiments, a double shot may be initiated without causing a single shot procedure.

It will be appreciated that operation of the device may be controlled by an operator via a suitable touch screen system (compare fig. 2) provided on, for example, the outer surface of the handle unit 105, including the initiation of the double-shot and single-shot procedures described above with reference to fig. 9-35, and the initiation of the jet flush.

In the embodiment described above with reference to fig. 1-38, control of the movement of the needle 50 and sample-receiving device 52 is broadly based on mechanical means, except for certain electronic control components, such as the solenoid 148 (compare, e.g., fig. 9 and 10), the motor 372, the vacuum pump 382 (fig. 36), and the peristaltic pump 118 for liquid flushing of tissue sample ejection. However, it should be understood that the control system may incorporate other electronic components. For example, the double shot and single shot firing mechanisms may be driven by separate motors that are electronically controlled, and the loading and firing of the single shot and double shot first and second mechanisms, respectively, may incorporate electronic control elements for causing appropriate engagement and disengagement of the various parts.

Fig. 39 and 40 illustrate two alternative embodiments of a control system for determining the distance between the first extended position of the sample-receiving device 52 and its second extended position, for example to provide automatic detection of the length of the outer hollow needle 50.

The control system uses the microcontroller 400 to constantly monitor the rotation of the motor unit 372 of the handle unit 105. At the same time, the system monitors the position of one of the drive shafts, which is part of the gear system that transmits movement from the motor unit to the bendable elongate element 66, using a suitable position sensor 371 (compare FIG. 36). Thus, the position of the bendable elongated element can be known in real time, and the system can configure itself according to the length of the bendable elongated element, and thus the outer needle 50 (compare, for example, FIG. 2).

The embodiment of fig. 39 and 40 includes three sensors that are directly connected to the motor unit 372 in the handle unit 105 and record the rotation of the motor, compare fig. 39. These sensors may be of the hall sensor type or similar, and their outputs are fed to the motor driver unit 402 and the microprocessor 400. When the motor unit 372 is activated and begins to rotate, motion is transferred from the motor to the bendable elongate element 66. As long as the bendable elongated element is free to move within the lumen of the outer hollow needle 50, a pulse of constant flow is fed from the hall sensor to the motor driver 402 and the microprocessor 400. When the bendable elongated element reaches the end of its range of movement, the rotation of the motor 372 is stopped and the pulsed constant flow from the sensor is interrupted. The microprocessor 400 registers this stopping of the pulse.

As an additional measure, the microprocessor 400 may record the position of the aforementioned drive shaft. Information about the position of the drive shaft may be provided by a potentiometer mounted on the drive shaft. The current position of the drive shaft and the full range of movement of the bendable elongate element 66 corresponding to the 300 degree rotational angle can be reflected from the brushes of the potentiometer. Since the position of the shaft when the bendable elongate element 66 reaches its second retracted position is recorded and can be found again using the output from the potentiometer, the microprocessor 400 can reduce wear on the motor by gradually reducing its speed and stopping it shortly before reaching the position corresponding to the second retracted position of the bendable elongate element 66.

An alternative or supplement to directly measuring the rotation of the motor 372 is to measure the motor current through the motor. The results of this measurement may be fed to a microcontroller or microprocessor, where suitable microprocessor programs or software include pre-defined current thresholds. The measurement of the motor current can be performed with a sampling a/D converter integrated with a microcontroller or a corresponding external device. As long as the bendable elongate element 66 is free to move within the lumen of the outer hollow needle 50, the load on the motor, and thus the motor current, is substantially constant. When the load increases because the rod or rack has reached the end of its range of movement, the motor current increases. When the current reaches a predefined threshold, the motor driver unit, which is an integral part of the control system, registers the current change. At the same time, the microcontroller can record the position of the drive shaft. The information about the position of the drive shaft may be provided by a suitable electrical or optical signal from, for example, a potentiometer.

A third method of communicating information about the bendable elongate element 66 to the microcontroller is to use a mechanical device, such as a spring loaded pin that slides into a notch in the bendable elongate element 66 or sample containment device 52. Also opto-mechanical means may be used.

Claims (5)

1. A biopsy device for obtaining at least one tissue sample from a living organism, the device comprising:

a hollow needle with a distal portion adapted for introduction into the living body;

a cutting mechanism for severing the at least one tissue sample;

a sample-receiving device with a cavity for receiving the at least one excised tissue sample, the sample-receiving device being receivable in and movable within the hollow needle;

a transport device for moving the sample-receiving device in the hollow needle between a first extended position, in which the sample-receiving device with the cavity is in a distal position and the cutting mechanism is capable of cutting off the at least one tissue sample, and a second retracted position, in which the sample-receiving device with the cavity is in a proximal position, the transport device comprising a bendable elongate element,

characterised in that the sample-receiving device is movable in the hollow needle along a movement axis, and at least one of the hollow needle and the sample-receiving device is configured to orient the sample-receiving device relative to the hollow needle in a plane substantially perpendicular to the movement axis.

2. The biopsy device of claim 1, wherein the sample-receiving device and the hollow needle are shaped to prevent relative rotational movement between the sample-receiving device and the hollow needle in a plane substantially perpendicular to the axis of movement.

3. The biopsy device of claim 1, further comprising a liquid supply unit adapted to contain a flushing liquid, the liquid supply unit being operatively connected to the cavity of the sample receiving device by the hollow liquid transport member, thereby allowing ejection of the tissue sample by liquid flushing.

4. The biopsy device of claim 1, further comprising a vacuum pump for creating a suction effect in the cavity of the sample-receiving device, the vacuum pump being in fluid communication with the cavity of the sample-receiving device through a longitudinally extending channel in the sample-receiving device.

5. The biopsy device of claim 1, further comprising:

a first user operable firing mechanism for longitudinally moving the hollow needle and sample containing device in a distal direction to penetrate the living tissue at or near the tissue mass to be examined;

a second user operable firing mechanism for longitudinally moving the hollow needle in a distal direction from a first position in which the sample-receiving device protrudes from the distal end of the hollow needle to a second position in which the hollow needle substantially receives the cavity of the sample-receiving device for severing said tissue sample from the remaining living tissue at the access location.