BRPI0701284B1 - SYSTEM FOR REMOVING HEAT FROM LIPID-RICH SUBCUTANEOUS CELLS - Google Patents

Abstract

COOLING DEVICE HAVING A PLURALITY OF CONTROLLABLE COOLING ELEMENTS TO PROVIDE A PREDETERMINED COOLING PROFILE A cooling device for removing heat from lipid-rich subcutaneous cells of a subject having skin is provided. The cooling device includes a plurality of cooling elements movable relative to one another to conform to the contour of the subject's skin. The cooling elements have a plurality of controllable thermoelectric coolers. The cooling elements may be controlled to provide a time-varying cooling profile in a predetermined sequence, may be controlled to provide a spatial cooling profile in a selected pattern, or may be adjusted to maintain constant process parameters, or may be controlled to provide a combination thereof.

Description

Cross-Reference to Related Requests

This application claims the benefit of U.S. Patent Application No. 11/528,225, filed September 26, 2006, and entitled "COOLING DEVICE HAVING A PLURALITY OF CONTROLLABLE COOLING ELEMENTS TO PROVIDE A PREDETERMINED COOLING PROFILE," which is incorporated herein by reference.

Technical Field

The present application relates generally to cooling devices, systems and methods for removing heat from subcutaneous lipid-rich cells, and more particularly, but not exclusively, to a cooling device having a plurality of controllable cooling elements to create a spatial cooling profile and/or a time-varying cooling profile in order to more efficiently affect subcutaneous lipid-rich cells.

Fundamentals

Excess body fat increases the likelihood of developing several types of diseases such as heart disease, high blood pressure, osteoarthritis, bronchitis, hypertension, diabetes, deep vein thrombosis, pulmonary embolism, varicose veins, liver stones, hernias, and several other conditions.

In addition to being a serious health risk, excess body fat can also degrade personal appearance and aesthetic performance. For example, excess body fat can form cellulite, which causes an “orange peel” effect on the surface of the skin. Cellulite is formed when subcutaneous fat protrudes into the dermis and creates dimples where the skin is attached to the underlying structural fibrous strands. Cellulite and excessive amounts of fat are often considered unattractive. Therefore, in view of the serious health risks and aesthetic concerns associated with excess fat, an effective way to control excessive body fat accumulation is urgently needed.

Liposuction is a method of selectively removing body fat to sculpt a person's body. Liposuction is typically performed by plastic surgeons and dermatologists using specialized surgical equipment that mechanically removes subcutaneous fat cells through suction. One disadvantage of liposuction is that it is a serious surgical procedure, and recovery can be painful. Liposuction can have serious and occasionally fatal complications. Additionally, the cost of liposuction is usually substantial.

Conventional noninvasive treatments for removing excess body fat typically include topical agents, weight-loss drugs, regular exercise, diet, or a combination of these treatments. One disadvantage of these treatments is that they may not be effective or even possible under certain circumstances. For example, when a person is physically injured or ill, regular exercise may not be an option.

Similarly, weight-loss drugs or topical agents are not an option when they cause an allergic or negative reaction. Additionally, weight loss in selective areas of a person's body cannot be achieved using systemic or general weight-loss methods. Other noninvasive treatment methods include applying heat to a zone of lipid-rich subcutaneous cells. U.S. Patent No. 5,948,011 describes altering subcutaneous body fat and/or collagen by heating the subcutaneous fat layer with radiation energy while cooling the skin surface. The applied heat degenerates the fibrous membranes made of collagen tissue and can destroy the fat cells beneath the skin, and the cooling protects the epidermis from thermal damage. This method is less invasive than liposuction, but it can still cause thermal damage to the surrounding tissue and can be painful for the patient. Another method of reducing subcutaneous fat cells is targeted cell cooling as described in U.S. Patent Publication No. 2003/0220674, the entire disclosure of which is incorporated herein. This publication describes, among other things, reducing the temperature of lipid-rich subcutaneous fat cells to selectively affect the fat cells without damaging cells in the epidermis. Although this publication provides promising methods and devices, several improvements to improve the implementation of these methods and devices would be desirable, including providing a plurality of controllable cooling elements to create a spatial cooling profile and/or a time-varying cooling profile to more efficiently affect the lipid-rich subcutaneous cells.

U.S. Patent Publication No. 2003/0220674 also describes methods for selectively removing lipid-rich cells and preventing damage to other structures including dermal and epidermal cells. A more efficient and precise method of controlling these effects is desirable. Therefore, a method for spatially cooling lipid-rich cells through a predetermined time-varying cooling profile, selected spatial cooling profile, or maintaining constant process parameters is also needed.

Brief Description of the Drawings

In the drawings, identical reference numbers refer to similar elements or similar acts. The relative sizes and positions of elements in the drawings are not necessarily shown to scale. For example, the shapes of many elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve the legibility of the drawing. Furthermore, particular shapes of elements as shown are not intended to convey any information concerning the actual shape of the particular elements, and have been selected only to facilitate recognition of the drawings.

Figure 1 is an isometric view of a system for removing heat from lipid-rich subcutaneous cells in accordance with one embodiment of the invention; Figures 2a, 2b, 2c and 2d are isometric views of a cooling device for removing heat from lipid-rich subcutaneous cells in accordance with embodiments of the invention; Figure 3 is an exploded isometric view of the cooling device of Figure 2a for removing heat from lipid-rich subcutaneous cells in accordance with one embodiment of the invention; Figure 4 is an additional exploded isometric view of the cooling device of Figure 3 illustrating additional components of the cooling device in accordance with another embodiment of the invention; Figure 5a is an isometric view of a plurality of heat exchangers connected in series in accordance with another embodiment of the invention. Figure 5b is an isometric top view of a plurality of heat exchangers connected in series in accordance with another embodiment of the invention. Figure 5c is an isometric bottom view of the heat exchangers of Figure 5b'; Figure 6a is an exploded isometric view of one of the heat exchangers illustrated in Figure 5a. Figure 6b is an isometric view of an alternative configuration of a cooling element of a heat exchanger in accordance with an embodiment of the invention; Figure 7 is a cross-sectional view of one of the cooling elements along line 7-7 of Figure 5a; Figure 8 is an isometric top view of an alternative cooling device for removing heat from subcutaneous lipid-rich cells in accordance with an embodiment of the invention; Figure 9 is an isometric bottom view of the alternative cooling device of Figure 8; Figure 10 is an illustrative cross-sectional view of a lateral cooling pattern in the dermis of the skin in accordance with another embodiment of the invention; Figure 11 is a block diagram illustrating the software modules of the computing system for removing heat from subcutaneous lipid-rich cells in accordance with another embodiment of the invention.

Detailed Description A. Overview

The present disclosure describes devices, systems, and methods for cooling lipid-rich subcutaneous cells. The term "subcutaneous tissue" means the tissue that lies beneath the dermis and includes adipocytes (fat cells) and subcutaneous fat. It will be appreciated that many of the details set forth below are provided to describe the following embodiments in a manner sufficient to enable one skilled in the relevant art to create and utilize the described embodiments. Many of the details and advantages described below, however, may not be necessary to practice certain embodiments of the invention. Additionally, the invention may include other embodiments that are within the scope of the claims but are not described in detail with respect to Figures 1-11.

Reference throughout this specification to "an embodiment" means that a particular feature or structure described with respect to the embodiment is included in at least one embodiment of the present invention. Accordingly, occurrences of the phrases "in an embodiment" or in various places throughout this specification do not necessarily all refer to the same embodiment. Additionally, the particular features or structures may be combined in any suitable manner in one or more embodiments.

The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.

The present invention is directed to a cooling device for removing heat from the lipid-rich subcutaneous cells of a subject. The cooling device includes a plurality of cooling elements movable relative to each other so as to be comfortable to the subject's skin.

One aspect is directed to a cooling device for removing heat from lipid-rich subcutaneous cells. The cooling device includes a plurality of cooling elements contained within interconnected frame elements rotatable about at least one axis, a plurality of heat exchange elements, and a housing. Alternatively, the cooling device includes a plurality of cooling elements contained in a flexible substrate. The cooling elements may utilize various cooling technologies including, for example, thermoelectric coolers, recirculating chilled fluid, vapor compression elements, or cryogenic phase change devices. Those skilled in the art will recognize that there are a number of other cooling technologies that may be utilized and that the cooling elements need not be limited to those described herein. Another aspect is directed to a cooling device having a plurality of cooling elements utilizing Peltier thermoelectric principles or other cooling technologies. The cooling device also includes a heat dissipation element in thermal communication with the cooling elements and a plurality of interface elements having heat exchange surfaces configured to contact the skin of the subject. The cooling elements may be capable of reducing a temperature of a region such that lipid-rich cells in the region are affected while cells that are not lipid-rich are generally unaffected.

Additional aspects include that the cooling device may include a plurality of interconnected hinged segments for rotation to conform to a body portion. Alternatively, the cooling elements may also be disposed on a flexible substrate and may be movable relative to one another. Another aspect is directed to a cooling device having a plurality of individually controlled cooling elements to provide a spatial cooling profile and/or a time-varying cooling profile. The cooling profile may, for example, be configured to provide cooling elements along a perimeter of the cooling device at a lower or higher temperature than cooling elements in an interior of the cooling device. Alternatively, the cooling profile may be configured to provide cooling elements in regions of the cooling device at a lower or higher temperature than cooling elements in adjacent regions of the cooling device. Additional aspects include that the cooling profile may vary over time to provide a decreasing or increasing temperature profile during treatment. Another aspect is directed to a method of applying a cooling device having a plurality of cooling elements contained in a plurality of interconnected hinged segments, each adjacent pair of hinged cooling elements being rotatable about at least one axis. The cooling elements may have a plurality of heat exchange surfaces capable of removing heat from the subject's skin. The method includes rotating hinged segments containing the cooling elements to achieve a desired configuration of the cooling device, cooling the heat exchange surfaces of the plurality of cooling elements to a desired temperature, placing the plurality of cooled heat exchange surfaces near the subject's skin, and reducing the temperature of a region such that lipid-rich cells in the region are affected while non-lipid-rich cells in the region are generally unaffected. Alternatively, the cooling elements can be arranged on a flexible substrate and movable relative to each other.

Additional aspects include a method of applying and maintaining pressure in the contact region. Additional aspects include securing the cooling device in position with a holding device. Additional aspects include providing a time-varying profile to increase or decrease the temperature of the cooling elements over a selected period of time. Additional aspects include spatially varying the temperature of each cooling element of the cooling device to provide discrete cooling regions in the cooling device. Another aspect is directed to a system for removing heat from subcutaneous lipid-rich cells. The system includes a cooling device having a plurality of frame segments containing cooling elements movable relative to one another, the frame segments being capable of achieving a desired orientation between each other, and a heat sink coupled to the cooling device for dissipating heat generated by the cooling device. In one embodiment, the frame segments are hinged. When placed near the skin of a subject, the plurality of cooling elements may be capable of reducing a temperature of a region such that lipid-rich cells in the region are affected while non-lipid-rich cells in the epidermis and/or dermis are generally unaffected.

Additional aspects include the cooling device being configured to follow the contours of the body. Additional aspects include the cooling device including a handle and/or may include a strap or other retention device to retain the cooling device in a selected position. Additional aspects include a control system for individually controlling the temperature of the cooling elements in a predetermined pattern. Additional aspects include a processing unit for controlling a time-varying cooling profile of the cooling device. B. System for Selective Reduction of Lipid-Rich Cells Figure 1 is an isometric view of a system 100 for removing heat from subcutaneous lipid-rich cells of a subject 101 in accordance with an embodiment of the invention. The system 100 may include a cooling device 104 located in an abdominal area 102 of the subject 101 or other suitable area for removing heat from the lipid-rich subcutaneous cells of the subject 101. Various embodiments of the cooling device 104 are described in greater detail below with reference to Figures 2-11. The system 100 may further include a cooling unit 106 and supply and return fluid lines 108a-b connecting the cooling device 104 to the cooling unit 106. The cooling unit 106 may remove heat from a refrigerant to a heat sink and supply a cooled refrigerant to the cooling device 104 via the fluid lines 108a and b. Examples of the circulating refrigerant include water, glycol, synthetic heat transfer fluid, oil, a refrigerant, and any other suitable heat-conducting fluid. Fluid lines 108a-b may be hoses or other conduits constructed from polyethylene, polyvinyl chloride, polyurethane, and other materials that can accommodate the particular circulating refrigerant. Cooling unit 106 may be a refrigeration unit, a cooling tower, a thermoelectric cooler, or any other device capable of removing heat from a refrigerant. Alternatively, a municipal water supply (i.e., tap water) may be used in place of the cooling unit.

As explained in greater detail below, the cooling device 104 includes a plurality of thermoelectric cooling elements, such as Peltier-type thermoelectric elements, which may be individually controlled to create a customized spatial cooling profile and/or a time-varying cooling profile. The system 100 may further include a power supply 110 and a processing unit 114 operatively coupled to the cooling device 104. In one embodiment, the power supply 110 may provide a direct current voltage to the thermoelectric cooling device 104 to effect the rate of heat removal from the subject 101. The processing unit 114 may monitor process parameters via sensors (not illustrated) located near the cooling device 104 via the power line 116 to adjust the rate of heat removal based on the process parameters. The heat transfer rate may be adjusted to maintain constant process parameters. Alternatively, the process parameters may vary spatially or temporally. The processing unit 114 may be in direct electrical communication via line 112, or alternatively, may be connected via wireless communication. Alternatively, the processing unit 114 may be preprogrammed to provide a spatially distributed cooling profile and/or a time-varying cooling profile. The processing unit 114 may include any processor, programmable logic controller, distributed control system, and the like.

In another aspect, the processing unit 114 may be in electrical communication with an input device 118, an output device 120, and/or a control panel 122. The input device 118 may include a keyboard, a mouse, a touch screen, a push button, a switch, a potentiometer, and any other suitable device for accepting user input. The output device 120 may include a display screen, a printer, a media reader, an audio device, and any other suitable device for providing feedback to the user. The control panel 122 may include indicator lights, numeric displays, and audio devices. In alternative embodiments, the control panel 122 may be contained within the cooling device 104. In the embodiment illustrated in Figure 1, the processing unit 114, the power supply 110, the control panel 122, the cooling unit 106, the input device 118, and the output device 120 are transported by a rack 124 with casters 126 for portability purposes. In alternative embodiments, the processing unit 114 may be contained within the cooling device 104. In another embodiment, the various components may be fixedly installed at a treatment site. C. Cooling Device Having a Plurality of Cooling Elements

Figures 2a, 2b, and 2c are isometric views of a cooling device 104 according to embodiments of the invention suitable for use in system 100. In this embodiment, cooling device 104 includes a control system housing 202 and cooling element housings 204a-g. Control system housing 202 includes a sleeve 308 (Figure 3) that may slide into collar 310 and/or may be mechanically attached to the cooling element housings. Cooling element housings 204a-g are connected to heat exchange elements (not shown) by fastening means 206. The fastening means may be any mechanical fastening device such as a screw or pin as is known in the art. The plurality of cooling element housings 204a-g may have many similar features. As such, features of the first cooling element housing 204a are described below with reference symbols followed by an "a", corresponding features of the second cooling element housing 204b are illustrated and noted by the same reference symbol followed by a "b", and so forth. The cooling element housing 204a may be constructed from polymeric materials, metals, ceramics, woods and/or other suitable materials. The example cooling element housing 204a illustrated in Figures 2a-c is generally rectangular, but may have any other desired shape. The cooling device 104 is illustrated in a first, relatively flat configuration in Figure 2a; in a second, slightly curved configuration in Figure 2b; and in a third, curved configuration in Figure 2c. As illustrated in Figures 2b and 2c, each segment of the cooling element housings 204a-g is rotatably connected to adjacent and movable segments about the connection 207a-f to allow the cooling device 104 to bend. The connection 207a-f, for example, may be a pin, a ball joint, a bracket, or other type of rotatable joint. The connection 207 may accordingly be configured to rotatably couple the first cooling element housing 204a to the second cooling element housing 204b. According to aspects of the invention, the first cooling element housing 204a is rotatable with respect to the second cooling element housing 204b (indicated by arrow A), each adjacent and movable pair of cooling elements being such that, for example, the angle between the first and second cooling element housings 204a and 204b is adjustable up to 45°. In this way, the cooling device is hinged such that it can assume a curved configuration as illustrated in Figure 2b or 2c, conforming to the skin of a subject.

An advantage of the plurality of rotating heat exchange surfaces is that the arcuate shape of the cooling device can concentrate heat transfer in the subcutaneous region. For example, when the heat exchange surfaces are rotated around a subject's body contour, the arcuate shape can concentrate heat removal from the skin. The control system housing 202 can house a processing unit for controlling the cooling device 104 and/or the fluid lines 108a-b and/or electrical power and communication lines. The control system housing 202 includes a wiring port 210 for the electrical and fluid supply lines (not illustrated for clarity). The control system housing 202 can additionally be configured to serve as a handle for a user of the cooling device 104. Alternatively, the processing unit can be contained in a location other than on the cooling device.

As illustrated in Figures 2a, 2b, and 2c, the cooling device 104 may further include at each end of the cooling device 104 retention devices 208a and 208b coupled to a frame 304. The retention devices 208a and 208b are rotatably connected to the frame by retention device coupling elements 212a-b. The retention device coupling elements 212a-b, for example, may be a pin, a ball joint, a bracket, or other type of rotary joints. Alternatively, the retention devices 208a and 208b may be rigidly affixed to the end portions of the cooling element housings 204a and 204b. Alternatively, the retention device may be attached to the control system housing 202. Retention devices 208a and 208b are each illustrated as tabs 214, each having a slot 216 therein for receiving an elastomeric band or strip (not illustrated for clarity) for retaining the cooling device 104 in place on a subject 101 during treatment. Alternatively, the cooling device may not contain any attached retention device and may be held in place manually, may be held in place by gravity, or may be held in place with a band, elastomeric strip, or non-stretchable fabric (e.g., nylon mesh) wrapped around the cooling device 104 and the subject 101.

As illustrated in Figures 2a-2c, the cooling element housings 204a-g have a first edge 218 and an adjacent second edge 220 of an alternating shape to allow the cooling device 104 to mate and thus configure in a planar configuration. The first edge 218 and second edge 220 are generally angled in the Figures; however, the shape may be curved, straight, or a combination of angles, curves, and straight edges that provide an alternating shape between adjacent segments of the cooling element housings 204a-g.

Figure 2d illustrates an isometric view of an alternative cooling device 104 according to embodiments of the invention suitable for use in system 100. In this embodiment, cooling device 104 includes a plurality of heat exchange elements 300a-g contained within a flexible substrate 350. As described with respect to Figures 2a-2c, adjacent heat exchange elements 300a-g are fluidly coupled in series by fluid lines 328.

According to aspects of the embodiment, the cooling elements 300a-g may be affixed to the flexible substrate 350, or may be embedded in the flexible substrate 350. The flexible substrate 350 may be constructed from polymeric materials, elastomeric materials, and/or other suitable materials. The flexible substrate 350 may additionally be an elastomer such as silicone or urethane or may be a fabric such as nylon. The flexible substrate 350 may also be a thin polymer such as polypropylene or ABS. The example of the flexible substrate 350 illustrated in Figure 2d is generally rectangular, but may have any other desired shape, including a matrix configuration or an anatomically specific shape. In accordance with aspects of this embodiment, the flexible substrate 350 acts as a living joint between the cooling elements 302a-g to allow the cooling elements 302a-g to conform to the skin of a subject.

Figure 3 is an exploded isometric view of a cooling device 104 according to an embodiment of the invention suitable for use in system 100. In this embodiment, the cooling device 104 includes a frame 304 having a plurality of rotatably connected segments 305a-g. The rotatably connected segments 305a-g are connected by hinges 306a-g. Alternatively, the rotatably connected segments 305a-g of the frame 304 may be connected by a connection that permits rotation, such as a pin, live joint, flexible substrate such as mesh or fabric, or the like. According to one aspect of the invention, the connections or hinges are made of plastic to isolate the cooling elements from each other.

A plurality of heat exchange elements 300a-g are contained in frame 304. Heat exchange elements 300a-g include cooling elements 302a-g having covers 301a-g. Covers 301a-g are affixed to an upper side of cooling elements 302a-g. Covers 301a-g may be affixed by various mechanical means as further described herein and as is known in the art. In accordance with aspects of the invention, covers 301a-g are fluid sealed to cooling elements 302a-g. In accordance with additional aspects of the invention, hinges 306a-g are configured to be adjacent to the subject's skin, in use, to maintain proximity between heat exchange elements 300a-g when heat exchange elements 300a-g are in a rotated position. The cooling elements 302a-g are secured by cooling element attachment means 307 to the frame 304 such that the first heat exchange element 300a is located on the first segment 305a of the frame 304 and the second heat exchange element 300b is located on the second segment 305b of the frame 304. The cooling element attachment means 307 is illustrated as a tab 313 extending from the frame 304 and a screw 315 securely attaching the tab 313 of the frame 304 to the cooling elements 302a-g. Alternatively, mechanical attachment devices as are known in the art may be utilized. The cooling elements 302a-g of the cooling device 104 are generally configured to rotate to allow the cooling device 104 to conform to an arcuate portion of a subject 101. Once positioned on a subject 101, the cooling device 104 may be further secured or otherwise configured to be releasably attached to the subject 101. The cooling elements 302a-g may be configured to move relative to one another or rotate to position the cooling elements 302a-g for applying pressure to the treatment area during operation. The cooling elements 302a-g are movable or rotatable relative to one another such that the cooling device 104 is conformable to the subject's skin. These features are described in greater detail below with reference to specific examples of the cooling devices. The first cooling element 302a may include the cooling element housing 205a, a fluid inlet port 310, and a fluid outlet port 316a. The fluid inlet port 310 is fluidly coupled to the fluid supply line 108a. As illustrated in Figure 3 , adjacent cooling elements are fluidly coupled in series by fluid lines 328 to fluid inlet ports 314a-f and fluid outlet ports 316a-f. The cooling element 302g further includes a fluid outlet port 312 fluidly coupled to the fluid return line 108b. An expected advantage of providing fluidly coupled cooling elements in series is a uniform flow rate through each cooling element 302a-g to provide more consistent cooling of the cooling device. Another expected advantage of providing the fluid-coupled cooling elements 302a-g in series is a smaller number of supply lines into the cooling device to provide a more reliable, less labor-intensive, and easier-to-house fluid flow configuration for the cooling device. Figure 4 is an additional exploded isometric view of the cooling device of Figure 3 in accordance with an example of the invention for use in system 100. This additional exploded view is substantially similar to the previously described examples, and common features and structures are identified by the same reference numerals. Only significant differences in operation and structure are described below. Cooling device 104 includes cooling elements 302a-g having a plurality of thermoelectric coolers 402 configured to reduce the temperature of a subcutaneous region of subject 101 to selectively affect lipid-rich cells in the region. The plurality of thermoelectric coolers 402, also known as a Peltier-type element, has a first side 404 and a second side 406. The first side 404 is in thermal communication with the cooling element 302, and the second side 406 is in thermal communication with an interface element 418. The thermoelectric coolers 402 may be connected to an external power supply (not shown) to transfer heat between the first side 404 and the second side 406. A suitable thermoelectric cooler is a Peltier-type cooling element (Model No. CP-2895) manufactured by TE Technologies, Inc. in Traverse City, Michigan. Thermoelectric coolers 402 are contained within segments 305a-g of frame 304. In accordance with aspects of the invention, frame 304 may contain individual guides for each thermoelectric cooler 402. Alternatively, thermoelectric coolers 402 may be retained on cooling elements 302a-g, for example, by thermal epoxy or by a combination of welding, mechanical compression, and thermal grease. As illustrated in Figure 4 , the plurality of cooling elements 302a-g may further include a plurality of interface elements 418 in thermal communication with the thermoelectric cooler 402 having heat exchange surfaces 420 for transferring heat to/from the subject 101. In one example, the interface elements 418 are generally planar, but in other examples, the interface elements 418 are non-planar (e.g., curved, faceted, etc.). The interface elements 418 may be constructed from any suitable material having a thermal conductivity greater than 0.05 Watts/Meter Kelvin, and in many examples, the thermal conductivity is greater than 0.1 Watts/Meter Kelvin. Examples of suitable materials include aluminum, other metals, metal alloys, graphite, ceramics, some polymeric materials, composites, or fluids contained in a flexible membrane. By applying power to thermoelectric coolers 402, callus can be effectively removed from the subject's skin into a circulating fluid in cooling elements 302a-g. For example, applying a current to thermoelectric coolers 402 can achieve a temperature generally below 37°C on the first side 404 of thermoelectric coolers 402 to remove heat from the subject 101 through interface elements 418. Thermoelectric coolers 402 draw heat from the second side 406 to first side 404 where the heat is then transferred to the circulating fluid. Cooling unit 106 then removes heat from the circulating fluid. Thermoelectric coolers 402 may be configured to remove a sufficient amount of heat quickly from the subject 101 without utilizing the high current power supply to the cooling unit 106. In order to facilitate heat transfer, the interface elements 418 may be an aluminum plate configured with generally the same dimensions as in the thermoelectric coolers 402. In accordance with aspects of the invention, the thermoelectric coolers 402 may be Peltier-type thermoelectric elements of about 160 watts. As such, the cooling device 104 may cool a portion of the subject's skin from a temperature of about 37° C. to about -20° C. quickly and effectively. The cooling unit 106 may utilize a normal voltage power supply (e.g., 120 VAC) since power consumption is not excessive. This allows the system to be used in hospitals, clinics, and small offices without expensive high voltage electrical systems. Figure 5a is an isometric view of a plurality of heat exchange elements 300a-g connected in series with the housing removed to better illustrate the plurality of heat exchange elements 300a-g and the interconnected fluid lines. In accordance with aspects of the invention, the heat exchange elements 300a-g are rotatably contained in connected segments of the frame 304 to provide a cooling device that is wider than it is tall. In this manner, the cooling device conforms to and will be shaped to follow contours. In accordance with aspects of the invention, the cooling device is dimensionally small in a first dimension such that curvature of the treatment area in a second dimension does not significantly impact the amount of surface area in contact between the skin and the cooling device.

According to additional embodiments of the invention, Figure 5b is an isometric top view of a plurality of heat exchangers connected in series by a hinge 350a, 350b, where the hinged connection is connected directly to heat exchanger 302a, 302b. The hinge 350a, 350b as illustrated in Figure 5b is a flat hinge that extends along adjacent edges of heat exchanger 300a, 300b for the length of heat exchanger 300a, 300b, alternatively, the connection 350a, 350b may extend for a portion of the length of adjacent sides of heat exchanger 300a, 300b or the hinged connection may include a plurality of hinges 350a, 350b. Unlike Figure 5a, no structure is employed to connect heat exchangers 300a, 300b or provide support for the hinged connection between heat exchangers 300a, 300b. Figure 5c is an isometric bottom view of the heat exchangers in Figure 5b. In accordance with additional aspects of the invention, mechanical hinged connections as are known in the art may be utilized alone or in combination; or, alternative chemical connections such as flexible adhesives or a live joint as are known in the art may be utilized in the hinged connections; or, electromechanical connections such as magnets may be utilized between the heat exchangers to connect the heat exchangers.

Figure 6a is an exploded isometric side elevation view of the heat exchange element 300a illustrated in Figure 5a to further illustrate fluid flow in the heat exchange element 300a. Like reference symbols refer to similar features and similar components in the Figures. As illustrated in Figure 6a, the heat exchange element 300a may include a fluid chamber 610 having a serpentine shape within the cooling element 302a. As illustrated in Figure 6b, heat exchange element 300a may include fins 612 for directing fluid flow through fluid chamber 610. Fluid chamber 610 may be in fluid communication with associated fluid ports so that fluid may flow through fluid chamber 610. Fluid chamber 610 may be configured to accept fluid coolants such as water, glycol, a synthetic heat transfer fluid, oil, refrigerants, air, carbon dioxide, nitrogen, and argon. In accordance with additional aspects of the invention, fluid chamber 610 may be configured in a variety of configurations as are known in the art in order to distribute fluid throughout cooling element 302a.

Figure 7 is a cross-sectional view of a cooling element 302a. The cooling element 302a is fluid sealed by the cover 301a containing an O-ring seal 722, held in place by a clamping means 326. In accordance with aspects of the invention, the cooling element 302a may further include at least one sensor element 710 proximate to the heat exchange surface 420 (Figure 4). The sensor element 710, for example, may be generally flush with the heat exchange surface 420. Alternatively, it may be recessed or may protrude from the surface. The sensor element 710 may include a temperature sensor, a pressure sensor, a transmission sensor, a bioresistance sensor, an ultrasound sensor, an optical sensor, an infrared sensor, a heat flux sensor, or any other desired sensor as further described herein.

In one example, the sensor element 710 may be a temperature sensor configured to measure the temperature of the first heat exchange surface 420 and/or the temperature of the subject's skin 101. For example, the temperature sensor may be configured as a probe or as a needle that penetrates the skin during measurement. Examples of suitable temperature sensors include thermocouples, resistance temperature devices, thermistors (e.g., neutron transmutation coated germanium thermistors), and infrared radiation temperature sensors. In another example, the sensor element 710 may be an ultrasound sensor configured to measure the crystallization or change in viscosity of subcutaneous fat in the treatment region of a subject. In another example, the sensor element 710 may be an optical or infrared sensor configured to monitor an image of the treatment region to detect, for example, epidermal physiological reactions to the treatment. The sensor element 710 may be in electrical communication with the processing unit 114 via, for example, a direct wired connection, a network connection, and/or a wireless connection.

Accordingly, the cooling device 104 may be in electrical communication with the processing unit 114, and the cooling temperature may be automatically adjusted by the processing unit 114. According to additional aspects of the invention, the temperature of the interface element 418 may be sensed by the sensor element 710 and the sensed electrical signal may be converted by the processing unit 114 into a process value for the temperature. In one embodiment, the processing unit 114 may include a Proportional, Integral and Derivative controller, which may adjust the power output to the thermoelectric coolers 402 to achieve and/or maintain the desired temperature.

According to additional aspects of the invention, the sensing element 710 may alternatively be a pressure sensor to sense the pressure exerted by the cooling element 302a against the subject 101. In one embodiment, the interface element 418 may be attached to the frame 304 such that the pressure applied against the heat exchange element 300a is transferred through the housing 204a to the pressure sensor. The pressure sensor may alternatively be configured to sense the pressure in the fluid chamber 610 to monitor pressure variations in the fluid chamber 610. Alternatively, the pressure may be inferred from the force and known contact area of the cooling elements. For example, the sensing element 710 may be any type of load-sensitive pressure sensing element such as a load cell (Model No. LC201-25) manufactured by OMEGA Engineering, Inc., Stamford, Connecticut. Direct pressure measurement may also be accomplished by placing a pressure measuring membrane directly at the interface between the cooling element and the skin. The cooling elements 302a-g may have many additional embodiments with different and/or additional characteristics without departing from the operation of the elements. For example, an adjacent cooling element may or may not have a sensor element near the heat exchange surface. Alternatively, the cooling elements may be constructed from a material that is different from the material of the adjacent cooling element.

Figure 8 illustrates an isometric view of a plurality of thermoelectric coolers contained in an array design. Figure 8 and Figure 9 are isometric views of an alternative cooling device for removing heat from subcutaneous lipid-rich cells in accordance with an embodiment of the invention. As illustrated in Figures 8 and 9 , the cooling device 810 includes a cooling element 804 configured in a planar array. The cooling device 810 may include a strap 812 for retaining the cooling element 804 in place during use. The cooling device may further include a handle 814, a harness 818, and a tab 816 for releasably securing the strap 812 to the cooling element 804. The cooling element 804 may further include a sleeve 822 as further described above.

As illustrated in Figure 9, the cooling element 804 includes a planar array 824 including a plurality of thermoelectric coolers 826. The thermoelectric coolers 826 are contained on a flexible substrate 830. The flexible substrate 830 may be an elastomer such as silicone or urethane or may be a fabric such as nylon. According to additional aspects, the flexible substrate 830 may be a thin polymer such as polypropylene or ABS. As described in greater detail herein, the thermoelectric coolers 826 may have small protective interface plates (not illustrated) bonded to the cold surface of the thermoelectric coolers 826 with a thermal epoxy. According to alternative embodiments of the invention, additional mechanical constraints may be further included in the flexible substrate 830 to capture the thermoelectric coolers 826. As described in greater detail herein, the thermoelectric coolers 826 may include a heat exchanger (illustrated and described with respect to Figures 3-7) on the hot side to cool the hot side. According to aspects of this embodiment, each thermoelectric cooler 826 may have a corresponding heat exchanger to provide increased flexibility for the planar array. Alternatively, a single flexible heat exchanger may be coupled to the hot side of the thermoelectric coolers (e.g., a bag or other flexible membrane through which water may be circulated).

According to alternative aspects of the embodiment, the planar array 824 may additionally include temperature sensors or other sensors (not illustrated) captured between the interface board and the thermoelectric coolers and/or may have a separate sleeve that houses the temperature sensors as further discussed herein.

D Cooling Device Operation

Figure 10 is an illustrative cross-sectional view of a lateral cooling pattern in the dermis of the skin. The cooling pattern radiates from the cooling elements 302a-f through the epidermis and dermis of the skin such that when it impacts the target dermis layer containing lipid-rich cells, the cooling pattern forms a uniform cooling layer and any gaps between the segments of the structure are mitigated. An expected advantage of this cooling pattern is that the cooling of the dermis layer is uniform throughout the treatment. Figure 10 depicts the cooling device 104 applied to a generally flat portion of a subject's body. The cooling elements 320a-f of the cooling device are movable relative to each other (as illustrated in Figures 2b, c and d) to conform to the contours of the subject's skin.

Without being bound by theory, it is believed that during operation, effective cooling from the cooling device 104, which cools by conduction, depends on a number of factors. Two illustrative factors that impact heat removal from the skin area are the surface area of the cooling element and the temperature of the interface element. When conduction occurs between two materials that are placed in physical contact, i.e., the skin and the cooling element, there is a certain amount of thermal resistance known as contact resistance. Contact resistance takes the form of a temperature differential between the two materials. Greater contact resistance means less effective cooling; therefore, it is desirable to minimize contact resistance in the cooling device.

One way to minimize contact resistance and maximize surface area of contact is with an interface element that is flexible and conforms to the natural contours of the body. According to alternative approaches, contact pressure can be reduced by increasing the pressure of the applicator on the skin. Surface pressure has an additional benefit in a skin cooling application. Sufficient pressure on the skin can cause internal capillaries to constrict, temporarily reducing blood flow within the treatment region. Reduced blood flow to the treatment area allows the area being cooled to cool more efficiently and improves treatment efficiency.

Thus, in accordance with aspects of the invention, the cooling device also incorporates a flexible fastening material or belt that wraps around the subject following the curvature of the cooling device. By tightening the strap, pressure is applied and can be maintained between the subject and the cooling device. In accordance with aspects of the invention, the strap may incorporate a loop or D-ring through which the strap can be looped to provide a mechanical advantage in tightening the strap. In accordance with additional aspects of the invention, the strap also incorporates Velcro or a latch or buckle to maintain pressure once the strap has been tightened.

During operation, an operator may hold the cooling device 104 in one hand by grasping the control system housing 202 or another suitable type of handle (not illustrated). Then the cooling elements 302a-g may be moved or rotated to achieve a desired orientation. The operator may place the cooling device 104 having cooling elements 302a-g in the desired orientation near the subject's skin to remove heat from a subcutaneous region of the subject 101. In one embodiment, the operator squeezes the holding devices 208a-b affixed to the cooling device 104 to apply pressure to the subject's skin. In another embodiment, the operator may manually press the cooling device 104 against the subject's skin. The operator can also monitor and control the treatment process by collecting measurements, such as skin temperatures, from the sensor element 710. By cooling subcutaneous tissues to a temperature below 37°C, more preferably below 25°C, the lipid-rich subcutaneous cells can be selectively affected. The affected cells are then reabsorbed by the patient through natural processes.

In accordance with aspects of the invention, interference elements 418, e.g., thin aluminum plates, are mounted to the bottom of thermoelectric coolers so as to ensure good thermal contact between the thermoelectric coolers and the interface elements. The interface elements may be coupled to the cooling element by a variety of mechanical attachment means such as those known in the art. For example, the coupling means may include thermally conductive epoxy or the use of thermal grease such as zinc oxide.

During operation, cooling is efficiently distributed across heat exchange elements 300a-g. For example, the cooling device includes a series of interface elements 418 approximately 1 mm thick. The interface elements 418 are in thermal communication with the cooling elements 302a-g by mechanical attachment such as thermal epoxy. The cooling elements 302a-g are cooled by a plurality of thermoelectric coolers to provide a more efficient cooling system for the treatment region. The cooling elements 302a-g are contained in segments that are movable relative to each other to conform to the contours of the subject's skin. Alternatively, the cooling elements are rotatable relative to each other, similar to the joined segments of a metal wristwatch band, thus allowing for curved mounting.

As designed, the interface elements and cooling elements protect the thermoelectric coolers while maintaining good heat transfer between the thermoelectric coolers and the skin. The interface elements are sized so that they do not present significant thermal mass. In one design, each thermoelectric cooler might be 1" x 1.5". The interface element or aluminum plate might also be 1" x 1.5" with a thickness of 0.4" (0.10 cm). If the cooling power of the thermoelectric coolers is approximately 10 W, which is adequate based on the heat flux expected to conduct to the skin, then the aluminum plate can cool from an ambient temperature of 20°C to a treatment temperature of -10°C in about 7 seconds. The change in internal energy of the plate is described by the following equation: ΔE=p-V-C-ΔT where ΔE is the change in internal energy, p is the material density, V is the material volume, C° is the heat capacity of the material, and ΔT is the temperature range. In the problem described above, the volume of the aluminum plate is V = 2.54 x 3.81 cm. x 0.10 cm. or 9.8 x 10-7m3. For a typical grade of aluminum, C° = 875 J/kg* °C and p=2770 kg/m3. Solving the equation using these constants: ΔE=2770 kg/m3*9.8x10-7m3*875 J/kg* °C30 C°=71.3 J

If the thermoelectric coolers have a cooling power of 10 W, then 71.3 J can be removed from the aluminum plate in 7.1 seconds as illustrated in the calculation below: 71.3 J/(10 J/seconds)=7.13 seconds.

A small space or recess in the structure at the surface of the skin may be included in one embodiment. Prior to application of the cooling device to the skin, a thermally conductive fluid or coupling agent may be applied to the device and the skin to minimize contact resistance and increase heat transfer between the cooling device and the skin. This coupling agent will fill the space in the cooling device and allow limited lateral conduction between the plates of the thermoelectric coolers. This will create a more uniform temperature gradient across the surface area of the skin when cooling is applied to the skin. The coupling agent may be applied to the skin and the interface element to provide improved thermal conductivity. The coupling agent may include polypropylene glycol, polyethylene glycol, propylene glycol, and/or glycol. Glycols, glycerols, and other deicing chemicals are effective freezing point depressants and act as a solution to reduce the freezing point of the coupling agent. Propylene glycol (CH3CHOHCH2OH) is an illustrative component of non-freeze or thaw coupling agents. Other components include polypropylene glycol (PPG), polyethylene glycol (PEG), polyglycols, glycols, ethylene glycol, dimethyl sulfoxide, polyvinyl pyridine, calcium magnesium acetate, sodium acetate, and/or sodium formate. The coupling agent preferably has a freezing point in the range of -40°C to 0°C, more preferably below -10°C, as further described in U.S. provisional application 60/795,799, entitled Coupling Agent For Use With a Cooling Device For Improved Removal of Heat From Subcutaneous-ous Lipid-Rich Cells, filed April 28, 2006, incorporated herein in its entirety by reference.

An expected advantage of using the cooling device 104 is that subcutaneous lipid-rich cells can generally be reduced without collateral damage to non-lipid-rich cells in the same region. In general, lipid-rich cells can be affected at low temperatures that do not affect non-lipid-rich cells. As a result, lipid-rich cells, such as subcutaneous adipose tissue, can be affected while other cells in the same region are generally not damaged despite the non-lipid-rich cells at the surface being subjected to even lower temperatures. Another expected advantage of the cooling device 104 is that it is relatively compact since the cooling device 104 can be configured as a portable device. Another additional advantage is that the cooling device can be applied to various regions of the subject's body since the cooling elements 302a-g can be adjusted to conform to any body contour. Another expected advantage is that by pressing the cooling device 104 against the subject's skin, blood flow through the treatment region can be reduced to achieve efficient cooling. Another additional expected advantage is the use of pressure by constricting the band to restrict blood flow to the treatment region and thereby reduce heat transfer (by mass transport). In this way, the band can not only provide a means of retaining the cooling element in place, but also ensures good thermal contact between the cooling device and the skin, and further restricts blood flow to the treatment region. Another additional expected advantage is that the plurality of cooling elements 302a-g more efficiently remove heat from the skin compared to a single cooling element.

And Spatially Controlled Cooling Element Profile

Many skin cooling devices rely on a relatively thick piece of aluminum or other conductive material sandwiched between a thermoelectric cooler or other cooling source and the skin. When a cooling device is applied to a relatively insulating material, such as skin tissue, the aluminum plate becomes isothermal and maintains a constant temperature profile across the skin surface. The disadvantage of this design is that when the device initially cools, or during the thermal cycle, the thermal mass presented by the aluminum plate requires a large amount of cooling energy. This translates into a longer cooling time or increased energy required by the cooling device, or both.

In accordance with aspects of the invention, the cooling device has a low thermal mass that will still maintain a constant temperature profile across the skin surface. Additionally, in accordance with aspects of the invention, a plurality of cooling elements are provided to allow different regions of the skin to be treated at different temperatures during a treatment session. There are some circumstances in which it may be desirable to cool different regions of the skin to different temperatures or for different periods of time. In accordance with aspects of the invention, each thermoelectric cooler may be individually controlled to cool different regions of the skin to different temperatures and/or for different periods of time and/or to ensure uniform temperature throughout the treatment region. One reason this may be desirable is that tissue composition is different at different locations on the body. Some regions have thicker layers of adipose tissue than others, which influences the thermal response of the skin. In other regions, the presence of bones or other organs will affect the transfer of heat to the skin.

In accordance with aspects of the invention, a spatially controlled temperature profile can provide more efficient cooling to the treatment region. The plurality of thermoelectric coolers allows the cooling device to accommodate spatial cooling. For example, thermoelectric coolers contained within the perimeter of the cooling device can have a lower or longer temperature or duration than thermoelectric coolers contained within the cooling device due to the different boundary conditions in different areas of the treatment zone. In accordance with aspects of the invention, the cooling device will rapidly and efficiently cool the skin to a prescribed temperature. Additionally, the cooling device described herein has the additional capability of treating a large area in a single treatment while cooling different regions at different temperatures and/or for different durations.

This variation in localized cooling can alternatively be achieved by using a cooling device that is relatively small so that many treatments are performed, cooling to different temperatures in different regions. However, this type of cooling device requires many treatments, thus increasing the total treatment time and the opportunity for operator error. Additionally, a cooling device with a large thermal mass would require a longer cooling time during each treatment.

In accordance with aspects of the invention, the device may accommodate spatially controlled cooling temperature profiles that may provide at least the following advantages: (1) increased efficiency; (2) reduced energy consumption with comparable efficacy; (3) increased patient comfort; or (4) reduced treatment time. For example, in accordance with aspects of the invention, the plurality of thermoelectric coolers will allow adjustment for anatomical differences between patients by selecting activation and deactivation of portions of the device based on the anatomical differences of the patient. One example includes deactivating thermoelectric coolers around bony anatomy to improve patient comfort or to conserve energy.

Alternatively, a particular controlled cooling pattern can be customized to match an individual patient's cellulite pattern, thereby increasing treatment efficacy. Similarly, treatment regions requiring higher treatment intensity can be pre-identified by ultrasound or other devices. The device can then be spatially controlled to deliver higher intensity treatment to the pre-identified areas. Additional advantages include increased patient comfort and increased safety by allowing spatial control of cooling to accommodate unnatural anatomy (e.g., bumps, nipples, hairy areas, scars, wounds, presence of implants, jewelry, or areas of increased sensitivity).

An additional advantage of spatial control of the device includes utilizing only a subset of the cooling elements in order to treat only the region requiring treatment. It is advantageous to utilize a device that can accommodate both small and large treatment regions without over-treating (e.g., a large device that cannot be spatially controlled) or requiring the device to be moved multiple times and thus extending the treatment time (e.g., a treatment device that is smaller than the treatment region). Thus, in accordance with aspects of the invention, a selected region of the thermoelectric coolers can be controlled a few degrees warmer than another region of the thermoelectric coolers. Alternatively, a first region of the cooling device can be turned off while a second region of the cooling device is turned on, such that only a selected region of the subject is treated, thereby limiting the treatment region. Other advantageous spatially controlled patterns include spacing treatment areas within the treatment region more intensely, conserving energy by alternating thermoelectric coolers, increasing cooling at a perimeter to provide a uniform cooling pattern across the treatment area, and a combination of these spatially controlled patterns to increase treatment efficacy, reduce treatment time, reduce energy consumption, and provide patient comfort and safety.

F. Time-Varying Cooling Profiles

In certain embodiments, once the desired temperature is reached, the temperature of the region may be maintained for a predetermined period of time. The cooling cycle may be terminated by separating the heat exchange surfaces 420a-g from the skin. After a certain period of time, if desired, the cooling device 104 may be reapplied to the same portion of the skin as described above until the lipid-rich cells are affected by a sufficient amount to produce a desired reduction in lipid-rich cells. In another embodiment, the cooling device 104 may be applied to a different portion of the skin as described above to selectively affect lipid-rich cells in a different target subcutaneous region.

Alternatively, the cooling elements 302a-g may be controlled according to a predetermined time-varying cooling profile to cool, heat, re-cool, and/or cool in a time-stepped temperature pattern. In particular, in accordance with aspects of the invention, time-controlled cooling patterns provide at least the following advantages: (1) increased efficiency; (2) reduced energy consumption with comparable effectiveness; (3) increased patient comfort; or (4) reduced treatment time. An illustrative cooling pattern includes cooling to -5°C for 15 min, heating to 30°C for 5 min, cooling to -3°C for 10 min. In accordance with aspects of the present invention, any desired time-varying cooling profile may be programmed into the device. For example, a gradual or stepped cooling rate may reduce energy requirements. Alternatively, a rapid cooling rate may be utilized in order to greatly cool the treatment region. Illustrative cooling rates include 5 to 1000 degrees per minute, more preferably 30 to 120 degrees per minute, and most preferably 35 to 100 degrees per minute.

An expected advantage of controlling the time-dependent temperature profile of the device is that in practice, tissue is sensitive to cooling rates and thus tissue damage can be controlled by controlling the rate of cooling of the treatment region. Additionally, cooling the treatment region over an extended period of time, or in phases, will increase patient comfort. Another expected advantage of several of the embodiments described above is that the cooling device 104 can selectively reduce subcutaneous lipid-rich cells without unacceptably affecting the dermis, epidermis and/or other tissues. Another expected advantage is that the cooling device 104 can simultaneously and selectively reduce subcutaneous lipid-rich cells while providing the beneficial effects to the dermis and/or epidermis. These effects may include: fibroplasia, neocollagenesis, collagen contraction, collagen compaction, increased collagen density, collagen remodeling, and acanthosis (epidermal thickening). In the treatment of cellulite, dermal thickening above the superficial herniated fat lobules is expected to help reduce the appearance of cellulite and improve the longevity of the effect. Another expected advantage is that the cooling device 104 can conform to various contours of a subject's body by rotating or moving the cooling elements 302a-g to achieve a desired orientation. Another expected advantage is that the cooling device 104 can be configured as a portable device for ease of operation. Additionally, another anticipated advantage is that the system 100 with the portable cooling device 104 and the rack-mounted processing unit 114 and cooling unit 106 will be compact and efficient so that the method described above can be administered in a clinic or physician's office rather than in a hospital. Another anticipated advantage is that the cooling device 102 can be locked in place to free the physician's hands and allow the physician to perform other tasks while the treatment is in progress.

G. Method of Applying Cooling Devices with a Plurality of Rotating or Moving Cooling Elements

During operation, the angle between the heat exchange surfaces 420 is selected by rotating or moving the cooling elements 302a-g. The angle between the cooling elements 320a-g is often selected to conform the heat exchange surfaces 320a-g to various contours of the subject's body 101 and/or a desired attachment arrangement. In the embodiment illustrated in Figure 2a, the angle between the heat exchange surfaces 320a-g may be generally 180°, that is, the heat exchange surfaces 320a-g are generally co-planar for application of the cooling device to a treatment region. In the embodiment illustrated in Figure 2b, the angle may be less than 180° to allow the cooling device to be further curved to conform to a subject's body. In other modalities, the angle may be any angle to conform to a subject's body, as would be recognized by those skilled in the art.

After configuring the cooling elements 302a-g, an operator places the cooling device 104 near the skin of the subject 101. In the embodiment illustrated in Figure 2a (where the angle is in a generally flat configuration), the cooling elements 302a-g are initially placed flat against the skin of a subject. The operator then rotates or moves the cooling device to conform to the body of a subject. The cooling device may be clamped by a strap, and a pressure may be increased by further tightening the strap. Optionally, the pressure sensor may be used to sense the clamping pressure applied across the interface elements 418, and the sensed clamping force may be processed by the processing unit 114 and displayed on the output device 120. The pressure may then be adjusted based on the displayed values. Depending on the location of the cooling device, the pressure, for example, may be greater than the systolic pressure at the skin to impede or block blood flow to the treatment region. Applying such pressure allows for more efficient cooling of the target region since there is less blood flow to transfer core body heat to the treatment region.

Applying the cooling device with pressure to the subject's skin or pressing against the skin may be advantageous in achieving efficient cooling. In general, the subject 101 has a body temperature of approximately 37°C, and blood circulation is a mechanism for maintaining a constant body temperature. As a result, blood flow through the dermis and subcutaneous layer of the region is a source of heat that reacts with the cooling of the subdermal fat. As such, if blood flow is not reduced, cooling of the subcutaneous tissues would require not only the removal of specific heat from the tissues but also the blood circulating through the tissues. Thus, reducing or eliminating blood flow through the treatment region may improve the efficiency of cooling and prevent excessive heat loss from the dermis and epidermis. By cooling the subcutaneous tissues to a temperature below 37°C, the lipid-rich subcutaneous cells can be selectively affected. In general, the epidermis and dermis of subject 101 may have higher amounts of unsaturated fatty acids compared with the underlying lipid-rich cells that make up the subcutaneous tissues. Since non-lipid-rich cells can usually withstand lower temperatures better than lipid-rich cells, the lipid-rich subcutaneous cells can be selectively affected while maintaining the non-lipid-rich cells in the dermis and epidermis. An illustrative range for cooling elements 302a-g may be from about -20°C to about 20°C, preferably from about -20°C to about 10°C, more preferably from about -15°C to about 5°C, most preferably from about -10°C to about 0°C.

Lipid-rich cells may be affected by disruption, shrinkage, deactivation, destruction, removal, death, or may be altered in some other way. Without being limited to theory, it is believed that the selective effect on lipid-rich cells results from localized crystallization of highly saturated fatty acids at temperatures that do not induce crystallization of non-lipid-rich cells. The crystals may disrupt the bilayer membrane of lipid-rich cells to selectively necrotize these cells. In this way, damage to non-lipid-rich cells, such as dermal cells, may be prevented at temperatures that induce crystal formation in lipid-rich cells. Cooling is thought to induce lipolysis (i.e., fat metabolism) of lipid-rich cells to further enhance the reduction in subcutaneous lipid-rich cells. Lipolysis can be improved by local exposure to cold, inducing stimulation of the sympathetic nervous system.

H. Computer System Software Modules

Figure 11 is a functional diagram illustrating illustrative software modules 940 suitable for use in processing unit 114. Each component may be a computer program, procedure, or process written as source code in a conventional programming language, such as the C++ programming language, and may be presented for execution by the CPU of processor 942. The various implementations of the source code and object and byte codes may be stored on a computer-readable storage medium or embodied in a recording medium on a carrier wave. The modules of processor 942 may include an input module 944, a database module 946, a process module 948, an output module 950, and, optionally, a display module 951. In another embodiment, the software modules 940 may be presented for execution by the CPU of a network server in a distributed computing scheme.

In operation, the input module 944 accepts an operator record, such as process setup point and control selections, and communicates the accepted information or selections to other components for further processing. The database module 946 organizes records, including operating parameters 954, operator activities 956, and alarms 958, and facilitates storage and retrieval of these records to and from a database 952. Any type of database organization may be used, including a flat file system, hierarchical database, relational database, or distributed database, such as that provided by a database vendor such as Oracle Corporation, Redwood Shores, California. The process module 948 generates control variables based on the readings from the sensor 960, and the output module 950 generates output signals 962 based on the control variables. For example, the output module 950 may convert the control variables generated from the process module 948 into 4 to 20 mA output signals 962 suitable for a direct current voltage modulator. The processor 942 may optionally include the display module 951 for displaying, printing, and downloading the readings from the sensor 960 and output signals 962 via devices such as the output device 120. A suitable display module 951 may be a video driver that allows the processor 942 to display the readings from the sensor 960 on the output device 120.

Unless the context clearly requires otherwise, throughout the description and claims, the words "comprises," "comprising," and the like are to be taken in an inclusive as opposed to an exclusive or exhaustive sense; that is, in a sense of "including but not limited to." Words using the singular or plural also include the plural or singular, respectively. When the claims use the word "or" with reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

The above detailed descriptions of embodiments of the invention should not be considered exhaustive or limiting the invention to the precise form described above. While specific embodiments and examples of the invention are described above for purposes of illustration, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while the steps are presented in a particular order, alternative embodiments may perform steps in a different order. The various embodiments described herein may be combined to provide additional embodiments.

In general, the terms used in the following claims are not to be construed as limiting the invention to the specific embodiments described in the specification, unless the detailed description above explicitly defines such terms. While certain aspects of the invention are set forth below in certain claim forms, the various aspects of the invention are contemplated in any number of claim forms. Accordingly, the right is reserved to add additional claims after the filing of the application to seek such additional claim forms for other aspects of the invention.

The various embodiments described above may be combined to provide additional embodiments. All U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications, and non-patent publications referred to herein in this specification and/or listed in the Application Data Sheet are incorporated herein by reference in their entirety. Aspects of the invention may be modified, if necessary, to employ cooling devices with a plurality of cooling elements, thermally conductive devices with various configurations, and concepts from the various patents, applications, and publications to provide additional embodiments of the invention.

These and other modifications may be made to the invention in view of the above detailed description. In general, in the following claims, the terms used are not to be construed as limiting the invention to the specific embodiments described in the specification and claims, but are to be construed as including all cooling that operates in accordance with the claims. Accordingly, the invention is not limited by the description, but rather its scope is to be determined entirely by the following claims.

Claims (14)

1. A system (100) for removing heat from lipid-rich subcutaneous cells of a subject (101) having skin, comprising: a cooling device (104) comprising a plurality of cooling elements (300a,b; 302a-g) rotatably coupled to one another by means of hinges (350a,b) defining axes so as to allow each of the cooling elements (300a,b; 302a-g) to rotate relative to one another and about at least one of the axes; wherein each of the cooling elements (300a,b; 302a-g) has a skin interface surface (420), wherein each cooling element (300a,b; 302a-g) includes a thermoelectric cooling element (402) and a fluid chamber (610) within the cooling element configured to maintain circulating coolant in thermal communication with the thermoelectric cooling element (402), and a control module in communication with the cooling device (104) and programmed to cause the thermoelectric cooling elements (402) to reduce the temperature of the cooling elements (300a,b; 302a-g) to -20°C to 0°C so as to cool subcutaneous lipid-rich cells. 2. The system (100) of claim 1, wherein the angle between the cooling elements (300a,b; 302a-g) can be rotated from 0° to 45°. 3. The system (100) of claim 1, wherein the cooling device (104) forms an arcuate shape configured to conform to a subject (101). 4. The system (100) of claim 1, further comprising a retention device for releasably retaining the cooling device on a subject (101). 5. The system (100) of claim 1, wherein the fluid chamber is in thermal communication with the interface elements and a plurality of fluid orifices are in fluid communication with the fluid chamber (610), and wherein the fluid orifices are configured to allow fluid circulation through the fluid chamber (610). 6. System (100) according to claim 5, CHARACTERIZED by the fact that the fluid in communication with the fluid chamber (610) is circulated through a device that cools the fluid. 7. System (100) according to claim 5, CHARACTERIZED by the fact that the fluid chambers (610) have a serpentine shape. 8. The system (100) of claim 5, wherein the cooling elements (300a,b; 302a-g) are fluidly connected in series. 9. The system (100) of claim 1, further comprising a thermally conductive coupling agent applied to an interface between the cooling device (104) and the subject's skin (101) to increase thermal conductivity between the cooling device (104) and the subject's skin (101). 10. The system (100) of claim 1 wherein each of the plurality of cooling elements (300a,b; 302a-g) has a first side in thermal communication with the corresponding interface element and a second side opposite the first side in thermal communication with the corresponding thermoelectric heat exchanger, wherein the cooling element is configured to reduce a temperature of the target region such that lipid-rich cells in the region are affected while non-lipid-rich cells proximate to the heat exchange surface are not significantly affected. 11. The system (100) of claim 1, further comprising a sensor element (710) proximate to at least one of the interface elements. 12. The system (100) of claim 1, further comprising: a first temperature sensor element proximate to at least one of the interface elements for detecting a temperature of a corresponding interface element; and a second temperature sensor element proximate to at least one of the interface elements for detecting a skin temperature of the subject. 13. System (100) according to claim 1, CHARACTERIZED by the fact that the joint is a living joint. 14. The system (100) of claim 1, wherein each of the cooling elements (300a,b; 302a-g) of the cooling device (104) includes a cover (310a-g) secured to an upper side of the cooling element.