Cryogenic System and Method of Use
A cryogenic medical device for delivery of subcooled liquid cryogen to various configurations of cryoprobes is designed for the treatment of damaged, diseased, cancerous or other unwanted tissues. The device is a closed or semi-closed system in which the liquid cryogen is contained in both the supply and return stages. The device is capable of generating cryogen to a supercritical state and may be utilized in any rapid cooling systems. As designed, the device comprises a number of parts including a vacuum insulated outer dewar, submersible cryogen pump, baffled linear heat exchanger, multiple pressurization cartridges, a return chamber, and a series of valves to control the flow of the liquid cryogen interconnected with cryotreatment devices including cryoprobes and catheters. The cryogenic medical device promotes subcooling to the tips of various external cryogenic instrument configurations.
This application is a continuation of U.S. patent application Ser. No. 15/445,968, filed Feb. 28, 2017, which is a continuation of U.S. patent application Ser. No. 14/336,317, filed Jul. 21, 2014, which is a continuation of U.S. patent application Ser. No. 13/061,171, filed Feb. 28, 2011, which is a National Stage entry of International Patent Application Ser. No. PCT/US2009/62928, filed Nov. 2, 2009, and is a continuation of U.S. patent application Ser. No. 12/553,005, filed Sep. 2, 2009, which claims priority to U.S. Provisional Patent Application Ser. No. 61/093,916, filed Sep. 3, 2008; and further is a continuation of U.S. patent application Ser. No. 12/562,301 filed Sep. 18, 2009, which claims priority to U.S. Provisional Patent Application 61/098,244, filed Sep. 19, 2008, the entirety of which are herein incorporated by reference.FIELD OF THE INVENTION
The present invention relates generally to the medical technology field and, in particular, to a cryogenic system.BACKGROUND OF THE INVENTION
Over a recent number of years, there has been a strong movement within the surgical community toward minimally invasive therapies. The main goals of the minimally invasive therapies include: 1) eradication of targeted tissue, 2) decreased hospitalization time, 3) limited postoperative morbidities, 4) shortened return interval to daily functions and work, and 5) reduced overall treatment cost. Cryotherapy is a minimally invasive method of treating a disease state through tissue freezing with thousands of patients now receiving the procedure annually. Currently, cryotherapy is used to treat numerous disease states including organ confined tumors such as prostate, kidney, liver, as well as cardiovascular disease, retinal detachment, pain management, and other illness/disease states.
Cryotherapy is an effective yet minimally invasive alternative to radical surgery and radiation therapy. The procedure is done under either general or epidural anesthesia. The procedure offers patients a quicker recovery and reduced severity of potential side effects. Without the expense associated with major surgery or an extended hospital stay, cryotherapy is a cost-effective treatment option.
The approaches utilized to date have focused on the delivery of liquid cryogen through the use of moderate to high pressure on the entire system or piston/bellows compression to drive fluid movement. At present, current systems utilizing liquid nitrogen operate at pressures between 14-480 psi; the systems in use cannot operate or withstand pressures greater that 500 psi. Further, the use of heat exchangers have been limited to coils placed into a bath of cryogen to allow for time consuming, inefficient passive subcooling of the cryogen in which activation of these devices circulate a cryogen (such as liquid nitrogen) to a probe to create a heat sink, thus resulting in tissue freezing.
There exists a need for improvements in cryotherapy, and medical devices or components associated with the treatment, to better circulate liquid cryogen to a cryoprobe, to provide for rapid delivery through small tubes, and to facilitate improved measures for treatment and cost. The system of the present invention will allow for the circulation (cooling, delivery, and return) of liquid cryogen to a cryoprobe for the freezing of targeted tissue. The invention will facilitate the eradication of tissue, decrease hospitalization time, limit postoperative morbidities, shorten return to daily functions and work, and further reduce the overall treatment cost. Desirably, these improvements to device design and application will also increase its utilization for the treatment of multiple disease states.SUMMARY OF THE INVENTION
The following invention is a cryogenic medical device designed to deliver subcooled liquid cryogen to various configurations of cryoprobes for the treatment of damaged, diseased, cancerous or other unwanted tissues. The device is a closed or semi-closed system in which the liquid cryogen is contained in both the supply and return stages.
By converting liquid nitrogen to supercritical nitrogen (SCN) in a cylinder/cartridge cooled by atmospheric liquid nitrogen (−1960 C.), the SCN can be subcooled and tuned to the liquid phase, attaining an excess temperature. When the SCN is injected into one or more flexible cryoprobes, the SCN flows with minimal friction to the tip of the probe. In the tip, SCN pressure drops due to an increased volume and outflow restriction, heat is absorbed (nucleate boiling) along the inner surface of the tip, micro bubbles of nitrogen gas condense back into a liquid, and the warmed SCN reverts to pressurized liquid nitrogen as it exits the return tube and resupplies the dewar containing atmospheric liquid nitrogen. This flow dynamic occurs within a few seconds, typically in the order of 1 to 10 seconds depending on the probe or attachment configuration, and is regulated by a high pressure solenoid valve. Further, once the instruments are in place, the cryosurgical procedure can be performed with freeze times in ranges of about 15 seconds to 5 minutes (or ranges thereof), a drastic improvement over current known methods. Upon emptying of the first cartridge subassembly, the process can be repeated with the second cartridge subassembly or any number of cartridges operated individually or in combination. Furthermore, embodiments of the present invention can be incorporated in any supercooling system or in delivering liquid cryogen to the desired instrument.
In one embodiment, the closed or semi-closed system has multiple pressurized cylinders filling and firing in sequence, and pressurized through a heating coil in one or more of the contained pressurized cylinders. The device is vented to the surrounding atmosphere through an adjustable pressure vent to prevent excess pressure buildup while in operation. The device comprises a number of parts including a vacuum insulated outer dewar, submersible cryogen pump, a series of self -pressurizing pulsatile delivery chambers, baffled linear heat exchanger, return chamber, and a series of valves to control the flow of the liquid cryogen. The outer dewar comprises a cryogenic apparatus having pressurizing pulsatile delivery chambers which drive liquid cryogen through the baffled linear heat exchanger. The linear heat exchanger comprises a tube-within-a-tube (i.e. chamber within a chamber configuration) whereby a vacuum is applied to the outer chamber to subcool an isolated reservoir of liquid cryogen. The inner chamber comprises a series of baffles and a central spiral to increase the flow path of the liquid cryogen while providing for increased contact-based surface area with the outer chamber to allow for more effective heat transfer and subcooling of the cryogen being delivered to the probe.
Following circulation to the cryoprobe, cryogen (liquid and gas) is returned to the device into a return chamber which surrounds the supply chamber, thereby providing for a staged secondary subcooling chamber for the cryogen in the supply tube. The return chamber is open to the main dewar tank thereby allowing for exchange of liquid and gas between the supply and return chambers. Device operation is controlled and monitored by a series of pressure and vacuum valves designed to control the flow, cooling, and pressurization of the liquid cryogen. This control is achieved through various configurations of manual and computer controlled systems.
In one embodiment of the invention, a cryogenic catheter or probe designed to deliver cryogen (liquid or gas) for the treatment of damaged, diseased, cancerous or other unwanted tissues is disclosed. The product/device is a tube within a tube and comprises a number of parts including a supply and return tubes (i.e. internal tubes), outer sheath (i.e. external tube) sealed to the inner tubes at one or both ends with a gas filled lumen between the internal and external tubes. The lumen of the external tube is filled with a non-equilibrating saturated gas which solidifies upon cooling, thereby creating a vacuum along the length of the catheter to provide for insulation between the inner and outer tubes and preventing freezing along the length of the probe shaft. Further the outside surface of the internal tubes is modified to potentiate gas nucleation on the outer surface of the internal tubes upon cooling.
At the distal end or tip of the probe shaft, the internal tubes come into contact with the outer tube and create a defined region of ultra cold temperatures to cool and freeze the target tissue region. The catheter is designed to carry liquid cryogen under various pressures as well as liquid cryogens of varying temperatures. Delivery of cryogen to the catheter is provided by a cryogenic medical device console through the connection of the longitudinal body.
In one embodiment, a dual insulative barrier is capable of being formed. The device creates a temperature initiated transient vacuum insulation along the length of a catheter. The device further couples the temperature initiated vacuum with that of a surface modification along the inner tubes/lines to enhance nucleation and deposition of the saturated gas on the outer surface of the inner tubes to create an additional layer of insulation. The enhanced deposition or nucleation modification contributes by making the vacuum more effective. In addition, the saturated gas filled lumen of the outer tube at ambient temperature may be run at any given pressure. For exemplary purposes and not limitation, one embodiment maintains the pressure at atmospheric levels or may control the pressure to elevated or reduced levels.
The invention is best understood from the following detailed description when read with the accompanying drawing figures. It is emphasized that the various features are not necessarily drawn to scale. In fact, the dimensions may be arbitrarily increased or decreased for clarity of discussion. Further, the below representations of a longitudinal body may not be drawn to scale where particular aspects extend the longitudinal body to lengths up to six feet and beyond (as dependent on the desired application).
In the following detailed description, for purposes of explanation and not limitation, exemplary embodiments disclosing specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one having ordinary skill in the art that the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. In other instances, detailed descriptions of well-known devices and methods may be omitted so as not to obscure the description of the present invention.
An external view of a device and system in accordance with one embodiment of the present invention is shown in
Within the internal cavity 15 of the dewar 6 is a submersible pump 1 which delivers the liquid cryogen to a sealed pressurization apparatus 40. In one embodiment, a valve 2 controls the pressure fill into internal open chamber 42 of the pressurization apparatus 40. Once the cryogen enters the pressurization apparatus 40, an immersion heater 44 housed in the internal open chamber 42 heats the cryogen to create a desired pressure. The liquid nitrogen within the pressurized chamber starts at a temperature of about −196° C. When the heater is activated, it boils the nitrogen within the immediate area. Temperature within internal cavity 42 therefore stays within about −196 0 C. to −150 0 C., more typically in the range of about −196 0 C. to −160 0 C., or rather between about −170 0 C. to −1600 C. Pressurized cryogen is then released through a valve 32 into the baffled linear heat exchanger 4. In one aspect, liquid nitrogen is converted to supercritical nitrogen (SCN) within the pressurization apparatus. The SCN is then directed to the heat exchanger for subcooling and tuned to the liquid phase to attain an excess temperature. Thereafter, the SCN can be injected into one or more flexible cryoprobes such that the SCN flows with minimal friction to the tip of the probe.
The baffled linear heat exchanger 4 in one embodiment is surrounded by a subcooling chamber 3 which subcools the pressurized cryogen for delivery to external cryoprobes. The subcooling chamber 3 in connection with the heat exchanger 4 at an entrance 23 and an exit opening 36 form an integral unit 51 for supplying subcooled liquid cryogen. From the heat exchanger 4, the subcooled cryogen passes into a supply line 11 and continues out through an exit port 35 and through a control valve 14 where various configurations of cryoprobes are attached. The subcooling chamber may attach a vent line to any of the vents 8, to a supply connecting line 19 controlled through a valve 27, or to a vacuum line 16 through a control valve 7 which is connected to a vacuum pump 18.
The cryogen is returned (as demonstrated by the arrows in
In operation, the device 30 is filled through a supply port 29 and then sealed to form a closed system, thereby allowing for the supply, return, collection, and re-utilization of liquid cryogen during its utilization in the medical/surgical field. The entire system 30 may or may not be pressurized during operation. The system may also be vented to the surrounding environment to prevent excess pressure buildup during operation. In one aspect, the returning cryogen empties into the return cylinder or chamber 5. In another aspect, the returning cryogen may empty as bulk fluid into the internal lumen 15 within the dewar 6.
In one embodiment of the present invention, the linear heat exchanger 4 subcools the liquid cryogen prior to delivery to tissue. In the embodiment of
Aspects of the linear heat exchanger 4 are illustrated in
One embodiment of the medical device comprises a return chamber 5 which is illustrated as a return cylinder 5 in
In another aspect, the return tube 12 is vented into the main dewar 6 either directly or by first passing through a linear heat exchanger (similar to the combination of heat exchanger 4 and subcooling chamber 3) to subcool the return cryogen prior to venting into the main dewar 6. Return of the cryogen to the main dewar 6 allows the cryogen to return through a heat exchanger such that the cryogen is reutilized and extends the operation time even longer.
In another embodiment, the medical device 30 may provide a system which is controlled through a series of computer controlled valves including any heaters, sensors, motors, or gauges. The sensors control and monitor pressure, temperature, and fluid level in the dewar, and can measure any metric as may be desired. In one aspect, the sensors monitor pressure levels within defined safety ranges. In another aspect, the sensors may control the pressurization of one or more components internal to the dewar. Any of the valves 2, 7, 8, 9, 27 or 32 including exit portal valve 14, maybe automated to enable a controlled and consistent operation of the cryogenic system (e.g. computer controlled operation through the electronically controlled valves).
An embodiment of a system 50 is shown in
From the heat exchanger, the subcooled cryogen passes into a supply line 11 and continues out through an exit port 35 where a control valve 14 is positioned and various configurations of cryoprobes are attached. The cryogen is returned (as demonstrated by the arrows in
During the operation of the system 50, as illustrated in the embodiment of
As depicted, the system 50 comprises a submersible liquid nitrogen pump 1 connected to a supply line 11 which directs the liquid nitrogen into a supply manifold 33. The supply manifold 33 routes the liquid nitrogen into at least one pulsatile pressurization chamber 40 where the liquid cryogen is heated. The pressurized liquid cryogen, here, liquid nitrogen, then starts filling the next pressurization cylinder/chamber 40 in the series such that when one chamber 40 is filling, another can be simultaneously pressurized and prepared for use. This permits a wave of activity through the cylinders so that it can cycle through each step of system operation. As the pressurized cryogen is delivered to the heat exchanger 4, and passes the subcooled pressurized cryogen out through the supply line 11 through the exit port 35 and into the attached cryoprobes, another pressurization chamber is filled and pressurized. The simultaneous use and pressurization of the liquid cryogen provides for the sequential delivery of liquid cryogen in a continuous series of pulsations to a cryogenic instrument or probe.
In one embodiment, liquid nitrogen is used; however, any cryogenic fluid may be utilized, including nitrogen, argon, helium, hydrogen, and other such desired fluids. Each pressurization apparatus 40 comprises a pressure valve controlled inlet 52, valve controlled outlet 54, and vent ports as may be desired, as well as an immersion heater 44. In one aspect, the filling of the pressurization apparatus 40 is controlled through a series of pressure valves 52 on the supply manifold 33. Liquid cryogen is heated within each pressurized apparatus. Pressurized liquid cryogen is then released through the control valve 54 to an outlet port/opening 46 of an outlet manifold 34 to the supply line 11, and delivered to a baffled linear heat exchanger 4. In the illustrated embodiment, a subcooling unit 3 surrounds the heat exchanger 4 for more rapid cooling.
In one embodiment, the cryogenic device 50 comprises six pressurized apparati 40 linked together. Other embodiments, however, may comprise any number of pressurized apparati 40 individually or linked together in combination. The apparati can then be controlled individually or in sequence to deliver pressurized liquid cryogen to the heat exchanger 4. In another aspect, one or more pressurization apparati 40 may be arranged to supply one or more cryoprobes. Further, the series of pressurized apparati 40 may be interconnected with another series of apparati 40.
In the embodiment of
Although the system may fill or discharge each cylinder 40 individually, any simultaneous fill or discharge, or rate of fill or discharge, may be incorporated into the system. The closed system keeps a constant supply of liquid nitrogen available for delivery to the cryoprobe and provides a more immediate and rapid rate of cooling for cryotherapeutic procedures. It is therefore possible to close the supply port 29 where supply tanks fill the dewar (See
In one embodiment, the pressurized chambers 40 are filled and the dewar sealed. A single drive pump 1 perpetuates directional flow of the cryogen into the pressurization chambers. In one embodiment, all chambers can be filled through various configurations of single direction pumping. In another embodiment, a reversible pump and fill method allows one pressurized chamber 40 to fill and then the pump 1 flips or reverses functionality to fill another pressurized chamber. This process can be repeated to fill any number of chambers.
In one embodiment, pressurized chambers 40 are enclosed completely within the dewar 6. However, any arrangement of the pressurized cylinders is possible so long as the closed system provides for the pulsatile delivery of cryogen to the cryoprobe. As such, any single or multiple configurations of cryoprobes or catheters may be used. Such instruments may also include cryoguns or cryodevices for rapid cryo-delivery processes or cryotherapies.
As illustrated in
Upon filling the dewar 206 with liquid nitrogen from an external source, an immersible liquid cryogen pump 201 is activated to fill each cryogen supply cylinder 202a & 202b, or cartridge, sequentially. Initially, one cartridge 202a is filled along with its linked cryogen pressurization cartridge 203a. Cryogenic solenoid valves 204 (a and b) provide venting of the gas within the cartridge assembly to support filling. Manifolds 208 (typically metal, stainless steel or aluminum) provide access points into the cartridges/cylinders 202, 203. The manifolds comprise components such as a heater, thermocouple, and the vent lines that pass through to the cylinders 202, 203. Upon completion of the filling process, the cryogen pressurization cartridge 203a is heated to generate a pressure of about 1000 psi (68 bar). Liquid nitrogen becomes critical at about 493 psi (34 bar) (BP=−147° C.). Pressurization beyond the critical point results in the formation of SCN, a dense fluid without surface tension and capable of frictionless flow, and with properties that may be tuned to either a gas or liquid.
By converting liquid nitrogen to SCN in a cartridge cooled by atmospheric liquid nitrogen (−1960 C.), the SCN is subcooled and tuned to the liquid phase, attaining an excess temperature (i.e. the ability to absorb heat without boiling) of approximately 500 C. When the SCN is injected into the flexible cryoprobe, the SCN flows with minimal friction to the tip of the probe (boiling chamber). In the tip, SCN pressure drops due to an increased volume and outflow restriction, heat is absorbed (nucleate boiling) along the inner surface of the TIP, micro bubbles of nitrogen gas condense back into a liquid, and the warmed SCN reverts to pressurized liquid nitrogen as it exits the return tube and resupplies the dewar containing atmospheric liquid nitrogen. This flow dynamic occurs within a few seconds and is regulated by a high pressure solenoid valve 204. Upon emptying of the first cartridge subassembly (202a & 203a), the process is repeated with the second cartridge subassembly (202b & 203b).
As demonstrated by
An external view of a device 65 in accordance with one embodiment of the present invention is shown in
The inner supply line 62 and return line 63 are maintained in the center of the outer sheath 61 by open configuration insulative spacers 53 placed throughout the catheter 65. The open configuration allows for a catheter lumen 64 to be filled with gas. The outer catheter sheath 61 is sealed to the connector 66 to create the gaseous lumen 64. The tip 68, in combination with the inner supply line 62 and the return line 63 come into contact with the outer sheath 61 at the distal end to develop a freezing region.
In addition, in one embodiment, the shaft 60 of the catheter 65 is flexible, as facilitated by a deflection wire 67 that runs along the shaft 60, the shaft of which is insulated by a temperature induced vacuum. The deflection wire 67 is a control line that runs down the shaft 60 to the tip of the catheter 65 to allow the catheter tip 68 to be moved on an angle, in a finger-like motion to steer and direct the catheter/probe 65 to the target tissue. In one embodiment, the deflection wire 67 guides the device 65 and monitors environmental measures of temperature, pressure, and/or physiological conditions. The guide 67 may integrate individual components and sensors such as an optical imaging component in connection with the guide or any number of thermocouples, pressure transducers, electrocardiogram monitors, or other electrophysiological sensors, alone or in combination.
Another embodiment of the present invention may use insulative foam (e.g. styrofoam, plastics, rubberized materials or other such insulative compositions) to separate the outer shaft 60 from the internal lines 62, 63 (i.e. inner supply line 62 and return line 63). Various aspects of the invention, however, accommodate a catheter tip 68 as designed to be steerable and deflectable to allow for guided targeting to the desired tissue site. In one aspect, spacers or insulative foam may be utilized to prevent internal supply and return lines from contacting the outer sheath. In another aspect, any freeze zone can be produced as designated by the configurations of catheter tips 68. (See
In the process of utilizing the catheter 65 of the present invention, a condensation based vacuum insulation is temperature dependent and located in the catheter 65. Upon the outer surfaces 69 of the walls of the supply line 62 and return line 63, a process of physically marking or chemically etching the surfaces 69 enhances nucleation and physical vaporization deposition of saturated gas. For exemplary purposes only and not limitation, the surface may be roughened, sprayed with any number of powder-like substances like silica, metallic particles and/or a carbon coating. The lumen 64 within the outer sheath 61 is filled with select vapors, or non-equilibrated phase change gas 64. In this embodiment, for example, butane is utilized which remains in a gaseous state at about room temperature, between about 00 C. to about 37° C. (See
In addition, one embodiment may interconnect a vacuum line of a cryosystem console with the catheter or probe 65 through a vacuum port 55 of the connector 66 as illustrated in
In the described embodiments, nucleation/sublimation in combination with a deposition process forms solid crystals along the supply line 62 and return line 63 outer walls, and spontaneously results in an evacuated space within the lumen 64. The evacuated space acts as an insulative barrier between the outer catheter sheath and the frost encased inner lines 62, 63. Film wise deposition along a length of the surfaces 69 of the supply line 62 and return line 63 results in crystalline film deposits of low thermal conductivity. The deposition may coat a portion of the outer surfaces or the entire outer surfaces of the inner lines to run the entire length of the internal tubes. (Note: The V marks in
Other aspects of embodiments of the present invention include gas as either a pure component or as a mixture of various components. Such gaseous compositions, for exemplary purposes only and not limitation, may comprise butane, carbon dioxide, iodine, camphor, and/or nitrous oxide.
In another embodiment, an enhanced nucleation surface 69 on inner tube/line 62, 63 surfaces may result where a process includes treating the walls of the inner lines 62, 63 to match nucleating efficiency with the chemical characteristics of the gas to be deposited (e.g. marking the surfaces with impurities, utilizing silica, or other powderized material, chemically coating or etching) and thereby create a similar effect.
Embodiments of the present invention manipulate the structural configurations of the tips 68, as illustrated in
In another embodiment of a distal end 110, as shown in
For example, and not limitation, cryogenic procedures performed within a vessel may advantageously make use of an inflatable cryogenic element 107 at the distal end of the probe so that the outer sheath expands as the internal inflatable cryogenic element expands.
Also depicted in
Another aspect of the probe/system in
As demonstrated in
In one embodiment, the distal end 128 is a needle-like probe end. In another embodiment, the distal end 128 takes the form of a blunt-tip probe end. The distal portion 128 may be integral with the tubular shaft or be removably placed in connection therewith. The interconnections of proximal connector, tubular shaft, and distal probe ends thus determines whether or not the individual parts, alone or in combination, may be reused, or disposed of. Further, the length of the distal end 28 may vary according to treatment procedure and may be any size, shape and dimension to correspond to the tissue treated.
The invention facilitates other improvements in cryotherapy, and medical devices or components associated with the treatment. The medical device of the invention allows for the circulation (cooling, delivery, and return) of liquid cryogen to a cryoprobe for the freezing of targeted tissue. The invention facilitates the eradication of tissue and can thereby decrease hospitalization time; further advantages reduce postoperative morbidities, shorten return to daily functions and work, and further lessen the overall treatment cost. These improvements to device design and application can also increase utilization of the device for the treatment of multiple disease states.
The device of the invention represents an approach in the development of cryosurgical devices by allowing for temperature induced transient vacuum insulation along the shaft of a cryoprobe or catheter; including insulating the shaft of a cryoprobe or catheter and delivery of cryogen in targeted thermal therapy. Furthermore, the device has been developed to couple the temperature initiated vacuum with that of a surface modification along the inner tubes to enable enhanced nucleation and deposition of the saturated gas on the surface of the inner tubes and create an additional layer of insulation. In one aspect, the device of the invention allows for the enhanced deposition on the outer surface of the inner tubes through modification of the tube surface, thereby creating an additional insulation barrier. In another aspect, the saturated gas filled lumen of the outer tube at ambient temperature may be either elevated or at atmospheric pressure.
The embodiments of the present invention may be modified to take the shape of any device, container, apparatus, or vessel currently used in industry. As disclosed herein, the cryoprobe device in the invention may be of any size, shape, or dimension. The device may be single use disposable or a multi-use/reusable part (and capable of being sterilized between individual patient treatments). In one embodiment, the longitudinal body extends up to about 6-8 feet or more. Any length, however, may be utilized as designed for particular therapies and treatments. Dimensions less than 12 inches, however, may also be better suited where attached tubing, removable, detachable, or disposable parts are integrated in the design. Specifically, cylindrical or alternative structural designs may be utilized in the cryogenic system for improved catheter/probe access to a tissue target. Further, any rearrangement of the tubes/lines in combination with the components of the above system may take many forms and be of any size, shape, or passageway.
In utilizing the medical device of the present invention, various methods in the industry may be employed in accordance with accepted cryogenic applications. As discussed, the embodiments of the present invention are for exemplary purposes only and not limitation. Advantageously, this device represents an important step in targeted thermal therapies. Various cryosurgical devices and procedures to apply freezing temperatures to a target tissue may be employed for use with the medical device of the present invention. The medical system disclosed herein has been developed to enable and improve some of the approaches used to target or ablate tissue. Furthermore, the medical device can couple controlled pumping of a liquid cryogen through a baffled linear heat exchanger to decrease the overall temperature of the cryogen providing a greater heat capacity of the fluid and thereby resulting in an increased cooling potential in a cryoprobe.
In one embodiment of the system, the mechanical and electrical mechanisms of the operational device is contained within a console, a shell or enclosure that allows the system to be easily transported. The enclosure may then include any mobile feature such as wheels, handles, and fixtures (or allow placement onto a cart having these features) so that the system can be transported to and from the location of treatment. Such mobility allows the system to be easily moved to and from an operating room or site of therapeutic treatment. It is also noted that the system is readily separable from the cryogen fill tanks and fill lines that initially supply the system with the liquid nitrogen or other such cryogenic fluid at the supply port 29 (As shown in
As presented, the multiple embodiments of the present invention offer several improvements over standard medical devices currently used in cryogenic industry. The improved cryogenic medical devices remarkably enhance its utilization for the cooling, delivery and return of a liquid cryogen to a cryoprobe for the freezing of targeted tissue. The present invention provides cost savings and significantly reduced treatment times which further reduce expenditures in the healthcare setting. The previously unforeseen benefits have been realized and conveniently offer advantages for the treatment of multiple disease states. In addition, the improvements enable construction of the device as designed to enable easy handling, storage, and accessibility. Further uses of the system outside of the healthcare setting are foreseeable. Potential uses in the space industry, defense systems or any industry requiring rapid cooling may incorporate the cryogenic system as thus described.
As exemplified, the device may include any unitary structure, vessel, device or flask with the capacity to integrally incorporate any combination of such structures. The invention being thus described, it would be obvious that the same may be varied in many ways by one of ordinary skill in the art having had the benefit of the present disclosure. Such variations are not regarded as a departure from the spirit and scope of the invention, and such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims and their legal equivalents.
1. A cryogenic system comprising:
- at least one cryoprobe having a freeze zone;
- a container capable of being filled with a cryogen;
- a pressurization apparatus having one or more heaters arranged therein to generate a pressurized cryogen, the pressurization apparatus having at least one port, wherein when the container is filled with the cryogen, (i) at least a first portion of the pressurization apparatus is positioned in the cryogen and is at a first temperature, and ii) at least a second portion of the pressurization apparatus is positioned outside the cryogen and is at a second temperature greater than the first temperature;
- a pump disposed in the container for delivering cryogen to the at least one port, wherein the pump is positioned in the cryogen when the container is filled with cryogen;
- at least one supply line in fluid communication with the at least one cryoprobe; and
- at least one return line that returns the cryogen from the at least one cryoprobe to the container.