Multiple gas circuit connectors and methods for cryoablation systems

Abstract

In one embodiment, a cryoablation system includes a precooler gas circuit, a working gas circuit isolated from the precooler gas circuit, and a vacuum chamber isolated from the precooler gas circuit and the working gas circuit. A cryoablation system may include a shaft having an isolated region and a working gas expansion chamber distal to the isolated region. The cryoablation system may also include a handle and a shaft-handle connector, where the proximal end of the shaft is connected to the shaft-handle connector, where the shaft-handle connector is configured to removably attach the proximal end of the shaft to the distal end of the handle.

Description

[0001] Cross-references to related applications

[0002] This application, filed May 23, 2024, is a PCT international patent application with the name Boston Scientific Scimed, a U.S. national company, as the applicant for all countries, and with U.S. citizens Kyle True, Eric T. Gagner, Timothy A. Ostroot, Cory Ross Stenberg, Benjamin Wai-Man Chan, and Zachary Nickle as inventors for all countries. This application claims priority to U.S. Provisional Application No. 63 / 537,324, filed September 8, 2023, and U.S. Application No. 18 / 671,677, filed May 22, 2024, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The embodiments described herein relate to cryoablation systems, and more specifically to cryoablation systems with detachable shafts. Background Technology

[0004] During cryoablation, surgeons can use one or more cryoprobes to ablate target areas of a patient's anatomy by freezing and thawing tissue. In one example, the cryoprobe uses the Joule-Thomson effect to generate cooling or heating at the probe tip. In this case, the expansion of the cryofluid in the cryoablation probe from higher to lower pressure cools the tip of the device to a temperature equal to or below the temperature corresponding to the cryoablation in the tissue near the tip. Heat transfer between the expanding cryofluid and the outer wall of the cryoprobe causes an ice ball to form in the tissue around the tip, thereby performing cryoablation of the tissue. Summary of the Invention

[0005] In a first aspect, the cryoablation system may include a precooler gas circuit, a working gas circuit, and a vacuum chamber working gas circuit. The cryoablation system may include a shaft having an isolation region along its proximal length. The isolation region may include an isolation portion of the vacuum chamber shaft and an isolation portion of the working gas circuit, wherein the vacuum chamber shaft portion surrounds and can be isolated from the isolation portion of the working gas circuit. The shaft may include a working gas expansion chamber located distal to the isolation region, wherein the working gas expansion chamber includes an expansion portion of the working gas circuit. The cryoablation system may include a handle having a handle portion of the vacuum chamber and a handle portion of the working gas circuit. The cryoablation system may also include a shaft-handle connector. The proximal end of the shaft may be connected to the shaft-handle connector, and the shaft-handle connector may be configured to removably attach the proximal end of the shaft to the distal end of the handle.

[0006] In a second aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some of the aspects, the shaft includes a supply tube extending along a portion of the length of the shaft, wherein the supply tube may be surrounded by a return tube along a portion of the length of the supply tube, wherein the return tube may be surrounded by an isolation shaft along an isolation region of the shaft, wherein the shaft-handle connector may be configured to form a seal around the outer surface of the isolation shaft.

[0007] In a third aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some of the aspects, the shaft-handle connector includes a first connector and a second connector, wherein a protrusion of the second connector can be configured to extend within a cavity defined within the first connector.

[0008] In the fourth aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some aspects, the inner surface of the protrusion of the second connector of the shaft-handle connector may be configured to form a seal around the outer surface of the return tube.

[0009] In the fifth aspect, in addition to one or more of the foregoing or following aspects, or as an alternative to some aspects, the second connector of the shaft-handle connector includes an internal space, and the inner surface of the internal space can be configured to form a seal around the outer surface of the supply tube.

[0010] In the sixth aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some aspects, the inner surface of the handle may be configured to form a seal around the outer surface of the shaft-handle connector.

[0011] In the seventh aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some of them, the shaft may be removed from the handle without impairing the handle portion's ability to isolate the working gas circuit and the handle portion's ability to isolate the vacuum chamber.

[0012] In the eighth aspect, in addition to one or more of the foregoing or following aspects, or as an alternative to some aspects, the shaft-handle connector includes a connector portion of a vacuum chamber, wherein the shaft-handle connector defines one or more openings that are in fluid communication with the connector portion of the vacuum chamber and are configured to connect to the vacuum chamber portion of the handle.

[0013] In the ninth aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some aspects, the shaft-handle connector defines one or more openings through which the return portion of the working gas circuit extends between the handle and the shaft-handle connector.

[0014] In a tenth aspect, in addition to one or more of the foregoing or following aspects, or as an alternative to some of them, the cryoablation system further includes a precooler gas circuit isolated from the working gas circuit and the vacuum circuit, wherein the handle includes a handle portion of the precooler gas circuit. The precooler gas circuit may be configured to supply precooler gas from a high-pressure cryogenic gas source to the handle, and the precooler gas circuit may include a precooler Joule-Thomson orifice at which the precooler gas enters the precooler expansion chamber.

[0015] In the eleventh aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some aspects, the working gas circuit may be configured to supply working gas from a high-pressure cryogenic gas source to the working gas expansion chamber, and the working gas circuit may include a working gas Joule-Thomson orifice at which the working gas enters the working gas expansion chamber.

[0016] In a twelfth aspect, the cryoablation system includes a working gas circuit and a vacuum chamber isolated from the working gas circuit. The cryoablation system may include a shaft having an isolation region along its proximal length, the isolation region having a vacuum chamber shaft portion and an isolation portion of the working gas circuit, wherein the vacuum chamber shaft portion surrounds and is isolated from the isolation portion of the working gas circuit. The shaft may include a working gas expansion chamber located distal to the isolation region, the working gas expansion chamber including an expansion portion of the working gas circuit. The cryoablation system may include a shaft-handle connector. A proximal end of the shaft may be connected to the shaft-handle connector, and the shaft-handle connector may be configured to removably attach the proximal end of the shaft to a distal end of a handle. The shaft-handle connector further includes: a working gas connector structure configured to form a sealed connection with a working gas supply passage and a working gas exhaust passage in the handle; a vacuum connector structure configured to form a sealed connection with the vacuum chamber portion of the handle; and a connector portion of the vacuum chamber isolated from the connector portion of the working gas circuit.

[0017] In the thirteenth aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some aspects, the shaft includes a supply tube extending along a portion of the length of the shaft, wherein the supply tube may be surrounded by a return tube along a portion of the length of the supply tube, wherein the return tube may be surrounded by an isolation shaft along an isolation region of the shaft, wherein the shaft-handle connector may be configured to form a seal around the outer surface of the isolation shaft.

[0018] In the fourteenth aspect, in addition to one or more of the foregoing or following aspects, or as an alternative to some aspects, the shaft-handle connector includes a first piece and a second piece, wherein a protrusion of the second piece can be configured to extend within a cavity defined within the first piece.

[0019] In the fifteenth aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some aspects, the inner surface of the protrusion of the second piece of the shaft-handle connector may be configured to form a seal around the outer surface of the return tube.

[0020] In the sixteenth aspect, in addition to one or more of the foregoing or following aspects, or as an alternative to some aspects, the second part of the shaft-handle connector includes an internal space, and the inner surface of the internal space can be configured to form a seal around the outer surface of the supply tube.

[0021] In the seventeenth aspect, in addition to one or more of the foregoing or following aspects, or as an alternative to some aspects, the shaft-handle connector includes a connector portion of a vacuum chamber, wherein the shaft-handle connector defines one or more openings that are in fluid communication with the connector portion of the vacuum chamber and are configured to connect to the vacuum chamber portion of the handle.

[0022] In the eighteenth aspect, in addition to one or more of the foregoing or below aspects, or as an alternative to some aspects, the shaft-handle connector defines one or more openings through which the return portion of the working gas circuit extends between the handle and the shaft-handle connector.

[0023] In the nineteenth aspect, in addition to one or more of the foregoing or the following aspects, or as an alternative to some aspects, the working gas circuit may be configured to supply working gas from a high-pressure cryogenic gas source to a working gas expansion chamber, the working gas circuit may include a working gas Joule-Thomson orifice at which the working gas enters the working gas expansion chamber.

[0024] In a twentieth aspect, a method of operating a cryoablation system may include providing the cryoablation system. The cryoablation system may include a working gas circuit. The cryoablation system may include a first catheter having a first shaft and a first shaft-handle connector. The first shaft may include a first working gas expansion chamber. The cryoablation system may include a handle having a handle portion having a working gas circuit. A proximal end of the first shaft may be connected to the first shaft-handle connector, and the first shaft-handle connector removably attaches the proximal end of the first shaft to a distal end of the handle. The method may include detaching a first catheter assembly from the handle. The method may include attaching a second catheter assembly to the handle. The second catheter assembly includes a second shaft and a second shaft-handle connector, the second shaft including a second working gas expansion chamber, wherein a proximal end of the second shaft is connected to the second shaft-handle connector. The second shaft-handle connector may be configured to removably attach the proximal end of the second shaft to a distal end of the handle.

[0025] This overview is a summary of some of the teachings of this application and is not intended to be an exclusive or exhaustive exposition of the subject matter. Further details can be found in the detailed description and the appended claims. Other aspects will become clear to those skilled in the art upon reading and understanding the following detailed description and examining the accompanying drawings, which form a part thereof, and nothing foregoing should be construed as limiting. The scope of protection herein is defined by the appended claims and their legal equivalents. Attached Figure Description

[0026] The following figures (figures) provide a more comprehensive understanding of the various aspects, including:

[0027] Figure 1 This is a schematic diagram of a cryoablation system according to various embodiments of this document.

[0028] Figure 2 This is a schematic diagram of a portion of a cryoablation system according to various embodiments herein.

[0029] Figure 3 This is a schematic diagram of a portion of a cryoablation axis as illustrated in various embodiments herein.

[0030] Figure 4 According to various embodiments herein Figure 3 The axis along Figure 3 The sectional view taken from section 4-4 in the figure.

[0031] Figure 5 According to various embodiments herein Figure 3 The axis along Figure 3 The sectional view taken from section 5-5 in the figure.

[0032] Figure 6 This is a schematic diagram of a cryoablation system according to various embodiments of this document.

[0033] Figure 7 According to various embodiments herein Figure 6 The cryoablation system along Figure 6 The sectional view of line 7-7 in the diagram.

[0034] Figure 8 According to various embodiments herein Figure 7 Cryoablation system about Figure 7 Close-up view of detail 8 in the image.

[0035] Figure 9 This is a side view of a shaft-handle connector according to various embodiments herein.

[0036] Figure 10 This is a cross-sectional view of the shaft-handle connector according to various embodiments herein.

[0037] Figure 11 This is an exploded side view of the shaft-handle connector according to various embodiments herein.

[0038] Figure 12 This is a side view of a catheter assembly according to various embodiments herein.

[0039] Figure 13 This is a cross-sectional view of a catheter assembly according to various embodiments herein.

[0040] Figure 14 This is a flowchart describing a method for using a cryoablation system according to various embodiments herein.

[0041] While the embodiments are susceptible to various modifications and alternatives, their details have been shown by way of example and accompanying drawings, and will be described in detail. However, it should be understood that the scope of this document is not limited to the specific aspects described. Rather, the invention is intended to cover modifications, equivalents, and alternatives that fall within the spirit and scope of this document. Detailed Implementation

[0042] Cryoablation (also known as cryotherapy or cryosurgery) is a medical procedure that involves using extremely cold temperatures to destroy or remove abnormal or diseased tissue. Cryoablation is used in a variety of medical fields, including oncology (cancer treatment), cardiology (cardiac treatment), dermatology (skin treatment), and more. In cryoablation, a shaft is inserted into or near the target tissue. This shaft contains a cryogenic substance, such as liquid nitrogen or argon, used to rapidly cool the tissue to very low temperatures. This extreme cold causes ice crystals to form inside the cells, leading to cell damage and ultimately cell death.

[0043] In some applications, cryoablation systems use rigid axes to deliver cryomaterial to the target anatomical structure. Rigid axes are generally more robust but offer limited access to the patient's anatomy. Some cryoablation systems can be used to ablate lesions in the biliary system or other hard-to-access parts of the human body. To access such anatomical features, flexible cryoablation axes can be implemented. However, flexible axes, containing high-pressure gas, are more challenging.

[0044] In most cases, after a cryoablation procedure, the cryoablation system catheter is considered a single-use item and is designed to be removable and replaceable. Where possible, it is desirable to reuse other parts of the cryoablation system, such as the handle and console, in multiple cryoablation procedures.

[0045] This disclosure relates to a cryoablation system having a removable catheter assembly. The catheter assembly may include a shaft and a shaft-handle connector. The shaft can be removably attached to a handle using the shaft-handle connector. The shaft-handle connector allows for replacement of the shaft of the cryoablation system while maintaining the isolation of multiple fluid loops (e.g., precooler gas, working gas, and vacuum) within the handle from each other.

[0046] The concepts described herein can be applied to the context of the cryoablation systems described in U.S. Patent Application Publication US2021 / 00045793 entitled “Dual Stage Cryocooler” and U.S. Patent Application Publication US2021 / 00045794 entitled “Flexible Cryoprobe”, both filed on August 14, 2020, the entire contents of which are incorporated herein by reference.

[0047] Now for reference Figure 1 This diagram illustrates a cryoablation system according to various embodiments herein. In various embodiments, the cryoablation system may include a handle 102 and a shaft 104. In various embodiments, the shaft 104 is insertable into the handle 102 and can be securely attached to the handle via a shaft-handle connector 103. In various embodiments, the shaft 104 and shaft-handle connector 103 of the cryoablation system 100 may form a conduit assembly. In some embodiments, the conduit assembly includes components of the cryoablation system that are replaced each time a cryoablation procedure is performed. In some aspects, the cryoablation system 100 may include a working fluid source 110, a precooler fluid source 112, and a vacuum source 114 that can be connected to the cryoablation system 100.

[0048] These three sources correspond to three independent loops in the cryoablation system 100: a precooler, a working fluid, and an active vacuum. In some embodiments, the working fluid source 110 and the precooler fluid source 112 are connected to the base of the handle 102 of the cryoablation system 100, and the vacuum source 114 is connected near the distal end of the handle, adjacent to the shaft-handle connector 103. The cryoablation system may also include a precooler gas vent 116 and a working gas vent 118 connected to the handle 102. In various embodiments, the shaft-handle connector 103 serves as a manifold to ensure that each flow loop remains isolated from each other.

[0049] In some embodiments, the cryoablation system 100 includes a console 117. This console can be used to control the system and can be electrically and fluidly connected to the handle and the cryoablation components. In some embodiments, a working fluid source 110, a precooler fluid source 112, and a vacuum source 114 can all be connected to the console 117 of the cryoablation system 100 via tubing. In some embodiments, a precooler gas vent 116, a working gas vent 118, or both can be connected to tubing that transports the effluent back to the console 117 or another location within the operating room, where the effluent is discharged into the surrounding environment at an appropriate location. It should be noted that the various sources and vents can be placed in appropriate locations along the handle 102 in any suitable configuration, and Figure 1The arrangement is merely an example of a suitable configuration.

[0050] The following paragraphs provide examples of the specifications and functions of each of these types of circuits. However, it should be noted that the specific fluid and pressure values ​​are for illustrative purposes only, and other configurations are possible.

[0051] In one embodiment, the precooler circuit may contain pressurized argon at 24.1 MPa. The precooler circuit can cool the incoming working fluid flow and can be operated in the handle. In one embodiment, the working fluid circuit may contain pressurized argon at 12.4 MPa and / or pressurized helium at 12.4 MPa. The working fluid circuit generates and / or melts ice balls. The working fluid circuit can operate in the handle, the isolated portion or area of ​​the shaft, and the expansion chamber of the shaft. In one embodiment, the active vacuum can maintain a vacuum level of less than or equal to 6.67 Pa. The active vacuum can isolate the shaft. The active vacuum can operate in the isolated areas of the handle and the shaft.

[0052] In various embodiments, a working fluid circuit passes through the handle 102 and shaft 104 of the cryoablation system 100 and carries the fluid that generates and melts the ice ball. The term "fluid circuit" is used throughout the application and may be replaced by gas circuit, liquid circuit, fluid chamber, gas chamber, or liquid chamber in various embodiments. The term "fluid" is used throughout the application and may be replaced by gas or liquid. The term "gas circuit" is also used throughout the application and may be replaced by fluid circuit, liquid circuit, fluid chamber, gas chamber, or liquid chamber in various embodiments. The term "gas" is used throughout the application and may be replaced by fluid or liquid.

[0053] During ablation (freezing cycle), argon gas at 12.4 MPa is circulated through the probe to create an ice ball within the patient body around the expansion chamber 106. The working fluid can be any suitable cooling fluid (e.g., nitrogen, air, argon, krypton, xenon, N2O, CO2, CF4). In some embodiments, the pressure of the high-pressure flow of the working fluid can be greater than or equal to 6.9 MPa, 8.3 MPa, 9.7 MPa, 11.0 MPa, 12.4 MPa, 17.2 MPa, 27.6 MPa, or 41.4 MPa. In some embodiments, the pressure of the high-pressure flow of the working fluid can be less than or equal to 55.2 MPa, 34.5 MPa, 20.7 MPa, 18.6 MPa, 16.5 MPa, 14.5 MPa, or 12.4 MPa. In some embodiments, the pressure of the high-pressure flow of the working fluid may fall within the range of 6.9 MPa to 41.4 MPa, or 8.3 MPa to 27.6 MPa, or 9.7 MPa to 16.5 MPa, or 11.0 MPa to 14.5 MPa, or may be approximately 12.4 MPa. Therefore, in embodiments where the working fluid is a cooling fluid, the temperature of the working fluid at the expansion chamber 106 may be approximately 190 Kelvin. In some embodiments, the temperature of the working fluid may be less than or equal to 250 Kelvin, 200 Kelvin, 150 Kelvin, or 100 Kelvin, or may be a temperature falling within any of the foregoing values.

[0054] In various embodiments, the precooler circuit is entirely contained within the handle 102. In various embodiments, the precooler circuit is located in the system's control console 117. In various embodiments, the precooler circuit is located in the portion of the conduit immediately proximal to the handle. In various embodiments, the precooler circuit is located in the portion of the conduit immediately distal to the handle. In various embodiments, the precooler circuit is operated using argon or any other suitable cooling fluid. In some embodiments, the pressure of the high-pressure flow of the precooler fluid may be greater than the pressure of the high-pressure flow of the working fluid. For example, the precooler fluid may be supplied at a pressure greater than about 13.8 MPa. In some embodiments, the pressure of the precooler fluid may be greater than or equal to 10.3 MPa, 13.8 MPa, 17.2 MPa, 20.7 MPa, or 24.1 MPa. In some embodiments, the pressure of the precooler fluid may be less than or equal to 31.0 MPa, 29.3 MPa, 25.9 MPa, or 24.1 MPa. In some embodiments, the pressure of the precooler fluid may fall within the range of 10.3 MPa to 31.0 MPa, or 13.8 MPa to 29.3 MPa, or 17.2 MPa to 27.6 MPa, or 20.7 MPa to 25.9 MPa, or may be approximately 24.1 MPa.

[0055] In some embodiments, the outer surface of shaft 104 may be thermally insulated from the inner surface of the shaft. In various embodiments, a vacuum circuit or vacuum chamber extends through the handle 102 and the isolation region 105 of shaft 104. Throughout the cryoablation procedure, a vacuum is actively drawn along the isolation region 105 of shaft 104, thereby providing a protective barrier between the outer surface of shaft 104 and the patient. In alternative embodiments, shaft isolation can be achieved by circulating fluid, gas, or heated fluid throughout the shaft or by electrically heating a portion of the shaft. In alternative embodiments, shaft isolation can be achieved by containing non-circulating fluid or gas within the isolation shaft.

[0056] The axis 104 can be of any suitable length capable of reaching the target anatomical structure within the subject's body. In some embodiments, the axis length can be greater than or equal to 20 cm, 38 cm, 55 cm, 72 cm, or 90 cm. In some embodiments, the axis length can be less than or equal to 150 cm, 135 cm, 120 cm, 105 cm, or 90 cm. In some embodiments, the axis length can be in the range of 20 cm to 150 cm, or 38 cm to 135 cm, or 55 cm to 120 cm, or 72 cm to 105 cm, or it can be approximately 90 cm.

[0057] In various embodiments, certain portions of shaft 104 may be flexible. In one embodiment, the entire length of the shaft may be flexible. For example, the shaft may be bendable about its longitudinal axis. In some such embodiments, the shaft may have a shaft diameter configured such that the shaft can have sufficient flexibility to form a curve with a desired radius of curvature. For example, the shaft may have sufficient flexibility to form a curve with a minimum radius of curvature less than or equal to 30 mm, 20 mm, 10 mm, or 5 mm.

[0058] In various embodiments, shaft 104 may include an isolation region 105 and an expansion chamber 106. The isolation region 105 defines a portion of shaft 104 isolated by a vacuum chamber. The expansion chamber 106 defines a portion of shaft 104 not isolated by a vacuum chamber, and in this portion, ice balls are generated. In various embodiments, the flexible shaft delivers high-pressure working fluid from handle 102 to expansion chamber 106, in which the high-pressure working fluid undergoes Joule-Thompson expansion and corresponding temperature changes. Before being discharged from the console to the atmosphere, the working fluid flows downwards from the flexible shaft, through the handle, or into and out of the handle.

[0059] The distal end of the shaft may terminate at a distal manipulator 108. During use, the distal manipulator 108 is deployed within the patient's body, surrounded by tissue, and in some cases, performs cryoablation of the tissue. In some cases, the distal manipulator 108 may be advantageously configured to puncture tissue. For example, the distal manipulator 108 may include a sharp tip, such as a cannula tip. Alternatively, the distal manipulator 108 may not be a sharp tip. In some embodiments, the distal manipulator 108 may be a damage-resistant tip designed to cause minimal tissue damage. In some embodiments, the distal manipulator 108 may also include a working port configured for aspiration, delivery of therapeutic agents, and delivery of any of other devices, including but not limited to guidewires, imaging catheters, sensing devices, biopsy devices, balloons, and stents.

[0060] Handle with precooler circuit ( Figure 2 )

[0061] Now for reference Figure 2 This diagram illustrates a portion of a cryoablation system according to various embodiments herein. In some aspects, the cryoablation system 100 may include a working fluid source 110 connected to a working fluid circuit and a precooler fluid source 112 connected to a precooler fluid circuit. The working fluid circuit may include a working fluid supply line 210 for delivering a high-pressure flow of working fluid from the working fluid source 110 to a distal end of the shaft 104 (not shown in this view). The working fluid circuit may also include a working fluid return line (not shown in this view) for delivering a low-pressure flow of working fluid from the distal end of the shaft back to the base of the handle 102.

[0062] The precooler fluid circuit may include a precooler supply circuit 212 terminating at a precooler Joule-Thomson orifice 223 and delivering a high-pressure flow of precooler fluid from the precooler fluid source 112 to the precooler fluid expansion zone 222 in the handle 102. The precooler fluid circuit may also include a precooler return line (marked by arrow 213). The precooler return line may be configured to return precooler fluid from the precooler fluid expansion zone 222 to the base of the handle 102. The precooler return line may be housed together with the precooler supply circuit 212 and extends back to the control console and gas manifold.

[0063] In various embodiments, the precooler fluid loop can facilitate heat exchange between the working fluid and the precooler fluid. For example, in embodiments where the working fluid is cooled during expansion to perform cryogenic ablation of tissue surrounding the distal operating tip 108, the precooler fluid loop can be used to precool the high-pressure flow of the working fluid. In various embodiments, the working fluid supply line 210 may include a first heat exchanger 216. This first heat exchanger 216 can facilitate heat exchange between the high-pressure flow of the working fluid in the working fluid supply line 210 and the low-pressure flow of the precooler fluid in the precooler return line.

[0064] In various embodiments, the precooler supply line 212 may include a second heat exchanger 218 that allows heat exchange (e.g., regenerative heat exchange) between a high-pressure flow and a low-pressure flow of the precooler fluid. In various embodiments, the precooler fluid may also be a cooling fluid. In such embodiments, regenerative heat exchange between the high-pressure and low-pressure flows of the precooler fluid can remove heat from the high-pressure flow. Therefore, the second heat exchanger 218 can facilitate precooling of the high-pressure flow of the precooler fluid.

[0065] In various embodiments, the high-pressure flow of precooler fluid exiting the second heat exchanger 218 continues to flow through precooler supply line 212 to precooler fluid expansion zone 222. Within the precooler fluid expansion zone, which is entirely contained within handle 102, precooler supply line 212 terminates at a Joule-Thomson orifice. The high-pressure flow of precooler fluid can expand at or downstream of the Joule-Thomson orifice in precooler fluid expansion zone 222. The rapid drop in pressure causes a corresponding drop in temperature. Precooler fluid expansion zone 222 can be in fluid communication with precooler return line to carry the expanded, low-pressure flow of precooler fluid (e.g., vented to the atmosphere if the precooler fluid loop is open, or returned to the precooler fluid source if the precooler fluid loop is closed). After expansion at the Joule-Thomson orifice, the cooled precooler fluid returns through handle 102 in the annular space between core tube 215 and the outer surface of handle 102. As the precooler fluid passes through the precooler return line, it cools the working fluid at the first heat exchanger 216.

[0066] The working fluid circuit 210 may also include a third heat exchanger 220 in the shaft 104 of the cryoablation system, which is configured for heat exchange (e.g., regenerative heat exchange) between the high-pressure flow of the working fluid in the working fluid supply circuit 210 and the low-pressure flow of the working fluid returning through the shaft 104 (not shown in this view).

[0067] Details of the distal end and expansion chamber ( Figure 3 )

[0068] Now for reference Figure 3 This diagram illustrates a portion of a cryoablation shaft according to various embodiments herein. In various embodiments, the shaft includes an isolation region 105 and an expansion chamber 106. In various embodiments, the isolation region 105 of shaft 104 includes a supply pipe 324 located within a return pipe 326, which is situated within an isolation shaft 328. The concentric shaft structure is designed to isolate the working fluid circuit 210 from the vacuum chamber 336.

[0069] In various embodiments, after exiting handle 102, the high-pressure flow of the working fluid travels downward along supply line 324. When the working fluid reaches working fluid expansion chamber 106, supply line 324 terminates at Joule-Thomson orifice 332 or distal outlet 332. The high-pressure flow of the working fluid can expand at or downstream of the Joule-Thomson orifice 332 in expansion chamber 106. The rapid drop in pressure causes a corresponding drop in temperature. Heat transfer between the expanding working fluid and the outer wall of expansion chamber 106 causes ice balls to form in the tissue surrounding end 108, resulting in cryoablation of the tissue.

[0070] Expansion chamber 106 may be in fluid communication with a working fluid return line (defined by the annular space between the inner surfaces of the supply line 324 and the return line 326 of the expansion chamber) to transport an expanded, low-pressure flow of the working fluid (e.g., vented to the atmosphere if the working fluid loop is an open loop, or returned to the working fluid source if the working fluid loop is a closed loop). As the working fluid passes through the working fluid return line, it is in the third heat exchanger 220 ( Figure 2 Cooling working fluid input flow at )

[0071] In various embodiments, the working fluid is a cooling fluid and a cooling gas (e.g., nitrogen, air, argon, krypton, xenon, N2O, CO2, CF4). In this case, the high-pressure flow of the working fluid can be at a pressure such that expansion via the Joule-Thomson orifice 332 can cause the working fluid to cool to a temperature suitable for cryogenic ablation of tissue surrounding the expansion chamber 106. In some aspects, the pressure of the high-pressure flow of the working fluid upstream of the Joule-Thomson orifice 332 can be approximately 6.9 MPa and approximately 13.8 MPa (e.g., approximately 12.4 MPa). Therefore, in embodiments where the working fluid is a cooling fluid, the temperature of the working fluid after expansion from the Joule-Thomson orifice 332 can be greater than or equal to 150, 160, 170, 180, 190, or 200 Kelvin, or can be an amount falling within any of the foregoing ranges.

[0072] The cryoablation system 100 can be designed such that the outermost surface of the shaft does not cause thermal damage to non-target structures. In various embodiments, ice ball formation is confined to the expansion chamber 106 of the shaft 104, which may also be referred to as the active region of the device. Selective ice ball formation is achieved by drawing a vacuum through the isolation region 105 of the shaft 104. In various embodiments, the cryoablation system 100 can be configured to establish a vacuum connection between the shaft 104 and the vacuum source 114.

[0073] refer to Figure 1 The cryoablation system 100 can be configured to connect to a vacuum source 114 at a handle 102. In various embodiments, the vacuum source 114 is configured to draw a vacuum along the length of the isolation region 105 of the shaft 104. In one embodiment, a vacuum is drawn through the entire isolation region 105 of the shaft 104, between the outer diameter of the return tube 326 and the inner diameter of the isolation shaft 328.

[0074] In various embodiments, the vacuum source 114 is configured to draw a vacuum within at least a portion of the handle 102. This configuration isolates the handle 102 and protects the cryoablation system operator from cryogenic exhaust gases. In some embodiments, the vacuum source 114 is connected to the handle 102, and the shaft 104 is in fluid communication with the handle 102, such that drawing a vacuum in the handle also evacuates the space between the supply line 324 and the return line 326. In other embodiments, the vacuum source 114 is directly connected to the shaft 104, for example, using a T-shaped fitting along the length of the shaft 104.

[0075] To provide thermal insulation along the isolation region 105 of axis 104, the flexible shaft has a double-walled structure (a return tube surrounded by the isolation shaft) with a small gap between the return tube 326 and the isolation shaft 328. By drawing a vacuum between the return tube and the isolation shaft, convective heat transfer is prevented, ensuring that the temperature of the working fluid does not ablate healthy non-target patient tissue along the isolation region of the axis or cause uncontrolled apoptosis / necrosis of healthy non-target patient tissue along the isolation region of the axis. Sufficient thermal insulation can be achieved by actively evacuating air from the gap and maintaining a vacuum of approximately 0.05 torr. However, other vacuum pressures may be appropriate depending on the configuration of the cryoablation system. In some embodiments, a support filament 330 is wound around the outer diameter of the return tube 326. One option for the filament material is a polymer such as polyetheretherketone (PEEK). This filament prevents direct contact between the outer surface of the return tube and the inner surface of the isolation shaft. The filament 330 minimizes thermal conduction between the inner shaft and the isolation shaft. Other alternatives can be used to replace filament 330, such as extruded tubular / co-extruded shapes or other features placed on the shaft.

[0076] In some embodiments, the shaft may not include filaments. In such embodiments, the return pipe 326 and the isolation shaft 328 are selected to have material properties sufficient to minimize thermal conduction between the inner shaft and the isolation shaft.

[0077] A joint 334 is present at the junction of the isolation zone 105 and the expansion chamber 106. This joint is capable of sealing the vacuum layer.

[0078] Cross-section, dimensions and material of flexible shaft ( Figure 4 )

[0079] Now for reference Figure 4 Various embodiments according to this document are illustrated. Figure 3 The axis is shown in a cross-sectional view taken along section 4-4. In various embodiments, the isolation region 105 of the shaft 104 includes a supply pipe 324 concentrically positioned within a return pipe 326 concentrically positioned within the isolation shaft 328. The isolation region 105 may include the axial portion of the vacuum chamber 336 and the isolation portion of the working gas circuit 210. In various embodiments, the vacuum chamber 336 surrounds and is isolated from the isolation portion of the working gas circuit 210.

[0080] In various embodiments, after exiting the handle 102, the high-pressure flow of the working fluid travels distally and downward through the supply pipe 324 to the isolation region of the shaft. After cooling and expanding in the expansion chamber 106, the working fluid travels proximally through the isolation region 105 of the shaft 104 in the annular space between the supply pipe 324 and the return pipe 326.

[0081] In various embodiments, the material and size of each layer of shaft 104 can be selected to provide a sufficient degree of flexibility so that the shaft can be bent about its longitudinal axis at the operating temperature of the device.

[0082] In various embodiments, the supply tube 324 (also referred to herein as a capillary) is made of any suitable material or one or more, such as flexible metal, polymer, composite material, etc. In one embodiment, the supply tube 324 is made of nickel-titanium (NiTi), stainless steel, etc.

[0083] In some embodiments, the inner diameter of the supply tube 324 may be greater than or equal to 0.30 mm, 0.35 mm, 0.40 mm, or 0.45 mm. In some embodiments, the inner diameter of the supply tube 324 may be less than or equal to 0.60 mm, 0.55 mm, 0.50 mm, or 0.45 mm. In some embodiments, the diameter of the supply tube 324 may fall within the range of 0.30 mm to 0.60 mm, or 0.35 mm to 0.55 mm, or 0.40 mm to 0.50 mm, or may be approximately 0.45 mm.

[0084] In some embodiments, the outer diameter of the supply tube 324 may be greater than or equal to 0.38 mm, 0.43 mm, 0.48 mm, 0.53 mm, or 0.58 mm. In some embodiments, the outer diameter may be less than or equal to 0.78 mm, 0.73 mm, 0.68 mm, 0.63 mm, or 0.58 mm. In some embodiments, the outer diameter may fall within the range of 0.38 mm to 0.78 mm, or 0.43 mm to 0.73 mm, or 0.48 mm to 0.68 mm, or 0.53 mm to 0.63 mm, or may be approximately 0.58 mm.

[0085] In some embodiments, the thickness of the supply tube 324 may be greater than or equal to 0.10 mm, 0.11 mm, 0.12 mm, 0.14 mm, or 0.15 mm. In some embodiments, the thickness of the supply tube 324 may be less than or equal to 0.20 mm, 0.19 mm, 0.18 mm, 0.16 mm, or 0.15 mm. In some embodiments, the thickness of the supply tube 324 may fall within the range of 0.10 mm to 0.20 mm, or 0.11 mm to 0.19 mm, or 0.12 mm to 0.18 mm, or 0.14 mm to 0.16 mm, or may be approximately 0.15 mm.

[0086] In various embodiments, the reflux tube 326 is made of any suitable one or more materials, such as flexible metals, polymers, etc. In various embodiments, the reflux tube 326 may be made of polyimide, fluorinated ethylene propylene (FEP), Teflon, etc. In one embodiment, the reflux tube 326 is formed of a polyimide material because it is highly impermeable to gases over a wide temperature range, thus allowing it to contain the working fluid internally and maintain a vacuum externally. In a particular example, the reflux tube 326 is made of a braided reinforced polyimide tube to enhance gas impermeability, burst strength, and flexibility. In some embodiments, the reflux tube 326 is formed of a single layer of material. In some embodiments, the reflux tube 326 may be formed of two or more layers of material, which are selected to optimize the performance of the shaft 104. The material layers can be bonded together using any suitable technique, such as adhesives, hot-melt reflux processes, etc.

[0087] In some embodiments, the outer diameter of the reflux tube 326 may be greater than or equal to 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, or 1.4 mm. In some embodiments, the outer diameter of the reflux tube 326 may be less than or equal to 1.8 mm, 1.7 mm, 1.6 mm, 1.5 mm, or 1.4 mm. In some embodiments, the outer diameter of the reflux tube 326 may fall within the range of 1.0 mm to 1.8 mm, or 1.1 mm to 1.7 mm, or 1.2 mm to 1.6 mm, or 1.3 mm to 1.5 mm, or may be approximately 1.4 mm.

[0088] In some embodiments, the inner diameter of the reflux tube 326 may be greater than or equal to 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, or 1.3 mm. In some embodiments, the inner diameter of the reflux tube 326 may be less than or equal to 1.7 mm, 1.6 mm, 1.5 mm, 1.4 mm, or 1.3 mm. In some embodiments, the inner diameter of the reflux tube 326 may fall within the range of 0.9 mm to 1.7 mm, or 1.0 mm to 1.6 mm, or 1.1 mm to 1.5 mm, or 1.2 mm to 1.4 mm, or may be approximately 1.3 mm.

[0089] In some embodiments, the thickness of the reflux tube 326 may be greater than or equal to 0.10 mm, 0.11 mm, 0.12 mm, 0.14 mm, or 0.15 mm. In some embodiments, the thickness of the reflux tube 326 may be less than or equal to 0.20 mm, 0.19 mm, 0.18 mm, 0.16 mm, or 0.15 mm. In some embodiments, the thickness of the reflux tube 326 may fall within the range of 0.10 mm to 0.20 mm, or 0.11 mm to 0.19 mm, or 0.12 mm to 0.18 mm, or 0.14 mm to 0.16 mm, or may be approximately 0.15 mm.

[0090] In various embodiments, the isolation shaft 328 is made of any suitable one or more materials, such as flexible metals, polymers, etc. In various embodiments, the isolation shaft 328 is made of polyimide, fluorinated ethylene propylene (FEP), Teflon, etc. In certain embodiments, the isolation shaft 328 may include polytetrafluoroethylene (PTFE) and / or one or more polyether block amides (trade name Pebax®, hereinafter “Pebax”).

[0091] In some embodiments, the isolating shaft 328 is formed of a single layer of material. In some embodiments, the isolating shaft 328 may be formed of two or more layers of material, which are selected to optimize the performance of the shaft 104. The material layers may be bonded together using any suitable technique, such as adhesives, hot melt reflow processes, etc.

[0092] In one embodiment, the isolation shaft can be formed using a braided reinforced polyimide tube with a Pebax outer layer. This three-layer structure allows for the maintenance of a high vacuum between the return tube and the isolation shaft without causing the isolation shaft 328 to collapse onto the return tube 326.

[0093] In some embodiments, the outer diameter of the isolation shaft 328 may be greater than or equal to 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, or 1.8 mm. In some embodiments, the outer diameter of the isolation shaft may be less than or equal to 2.2 mm, 2.1 mm, 2.0 mm, 1.9 mm, or 1.8 mm. In some embodiments, the outer diameter of the isolation shaft may fall within the range of 1.3 mm to 2.3 mm, or 1.4 mm to 2.1 mm, or 1.5 mm to 2.0 mm, or 1.6 mm to 1.9 mm, or may be approximately 1.8 mm.

[0094] In some embodiments, the inner diameter of the isolation shaft 328 may be greater than or equal to 1.0 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.6 mm. In some embodiments, the inner diameter of the isolation shaft 328 may be less than or equal to 2.2 mm, 2.0 mm, 1.9 mm, 1.8 mm, or 1.6 mm. In some embodiments, the inner diameter of the isolation shaft 328 may fall within the range of 1.0 mm to 2.2 mm, or 1.2 mm to 2.0 mm, or 1.3 mm to 1.9 mm, or 1.4 mm to 1.8 mm, or may be approximately 1.6 mm.

[0095] In some embodiments, the thickness of the insulating shaft 328 may be greater than or equal to 0.10 mm, 0.11 mm, 0.12 mm, 0.14 mm, or 0.15 mm. In some embodiments, the thickness of the insulating shaft 328 may be less than or equal to 0.20 mm, 0.19 mm, 0.18 mm, 0.16 mm, or 0.15 mm. In some embodiments, the thickness of the insulating shaft 328 may fall within the range of 0.10 mm to 0.20 mm, or 0.11 mm to 0.19 mm, or 0.12 mm to 0.18 mm, or 0.14 mm to 0.16 mm, or may be approximately 0.15 mm.

[0096] In some embodiments, PEEK filaments 330 are wound around a return tube 326. The pitch of the PEEK filaments 330 may be greater than or equal to 0.5 mm, 1.0 mm, 1.5 mm, or 2.0 mm, or may be an amount falling within any of the foregoing values. Alternatively, the filaments may be multiple discrete pieces attached along the return tube 326. The PEEK filaments 330 prevent direct contact between the return tube 326 and the isolation shaft 328, maintaining their coaxial alignment. In some embodiments, an adhesive (e.g., Loctite) is applied to the filaments at the ends of the return tube 326 and the isolation shaft 328 to attach the PEEK filaments 330. In various embodiments, the PEEK filament winding is configured to minimize or prevent convective heat transfer from the return tube to the isolation shaft. In alternative embodiments, other isolation polymers may be used as substitutes for the PEEK filaments, such as expanded polytetrafluoroethylene (ePTFE), nylon, etc.

[0097] In some embodiments, the diameter of the PEEK filament 330 may be greater than or equal to 0.002 mm, 0.004 mm, or 0.005 mm. In some embodiments, the diameter of the PEEK filament 330 may be less than or equal to 0.007 mm, 0.006 mm, or 0.005 mm. In some embodiments, the diameter of the PEEK filament 330 may fall within the range of 0.002 mm to 0.007 mm, or 0.004 mm to 0.006 mm, or may be approximately 0.005 mm.

[0098] Shaft inside the expansion chamber ( Figure 5 )

[0099] Now for reference Figure 5 Various embodiments according to this document are illustrated. Figure 3 The axis is taken along the cross-sectional view of section 5-5. Figure 5 The cross-sectional view depicts the expansion chamber 106 of shaft 104. In various embodiments, the expansion chamber 106 is located distal to the isolation region 105 along shaft 104. The expansion chamber 106 may include an expansion portion of the working fluid circuit 210.

[0100] In various embodiments, after exiting the handle 102, the high-pressure flow of the working fluid travels downward along the supply line 324. After being cooled and expanded in the expansion chamber 106, the working fluid travels downward through the annular space between the supply line 324 and the outer wall of the expansion chamber. In various embodiments, the expansion chamber 106 is configured to maximize heat transfer between the working gas and the patient tissue by optimizing parameters such as wall thickness and material.

[0101] In various embodiments, the expansion chamber 106 is made of any suitable one or more materials, such as flexible metals, polymers, etc. In various embodiments, the expansion chamber 106 is made of polyimide, fluorinated ethylene propylene (FEP), Teflon, etc. In some embodiments, the expansion chamber 106 includes a continuation of the return pipe 326 of the isolation region 105 of the shaft 104. Alternatively, the expansion chamber is a separate component from the return pipe 326, which can be coupled to the shaft 104 using any suitable joints and / or fittings, such as hot melt reflow processes, adhesive bonding, brazing, or any other suitable mechanical coupling process capable of withstanding low-temperature pressure and temperature.

[0102] In some embodiments, the expansion chamber 106 is formed of a single layer of material. In some embodiments, the expansion chamber 106 is formed of two or more layers of material. The material layers can be bonded together using any suitable technique, such as adhesives, hot melt reflow processes, etc.

[0103] In some embodiments, the outer diameter of the expansion chamber 106 may be greater than or equal to 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, or 1.7 mm. In some embodiments, the outer diameter of the expansion chamber 106 may be less than or equal to 2.1 mm, 2.0 mm, 1.9 mm, 1.8 mm, or 1.7 mm. In some embodiments, the outer diameter of the expansion chamber 106 may fall within the range of 1.3 mm to 2.1 mm, or 1.4 mm to 2.0 mm, or 1.5 mm to 1.9 mm, or 1.6 mm to 1.8 mm, or may be approximately 1.7 mm.

[0104] In some embodiments, the inner diameter of the expansion chamber 106 may be greater than or equal to 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, or 1.4 mm. In some embodiments, the inner diameter of the expansion chamber 106 may be less than or equal to 1.8 mm, 1.7 mm, 1.6 mm, 1.5 mm, or 1.4 mm. In some embodiments, the inner diameter of the expansion chamber 106 may fall within the range of 1.0 mm to 1.8 mm, or 1.1 mm to 1.7 mm, or 1.2 mm to 1.6 mm, or 1.3 mm to 1.5 mm, or may be approximately 1.4 mm.

[0105] In some embodiments, the wall thickness of the expansion chamber 106 may be greater than or equal to 0.20 mm, 0.22 mm, 0.25 mm, 0.28 mm, or 0.30 mm. In some embodiments, the wall thickness of the expansion chamber 106 may be less than or equal to 0.40 mm, 0.38 mm, 0.35 mm, 0.32 mm, or 0.30 mm. In some embodiments, the wall thickness of the expansion chamber 106 may fall within the range of 0.20 mm to 0.40 mm, or 0.22 mm to 0.38 mm, or 0.25 mm to 0.35 mm, or 0.28 mm to 0.32 mm, or may be approximately 0.30 mm.

[0106] Cryoablation system ( Figures 6-8 )

[0107] Now for reference Figures 6-8 This shows various views of the cryoablation system. Figure 6 This is a schematic side view of a cryoablation system according to various embodiments herein. Figure 7 According to various embodiments herein Figure 6 The cryoablation system along Figure 6 Line 7-7 is a cross-sectional view of the plane of the page. Figure 8 According to various embodiments herein Figure 7 Cryoablation system about Figure 7 A close-up view of detail 8. Referring to the accompanying drawing, arrows have been added to indicate the distal direction 637 and the proximal direction 639.

[0108] In various embodiments, the cryoablation system 100 may include a handle 102 and a shaft 104. In some aspects, the cryoablation system 100 may include a working gas source 110, a precooler gas source 112, and a vacuum source 114, which may be connected to the cryoablation system 100. These three sources correspond to three independent loops in the cryoablation system 100: the precooler gas supply loop 212, the working gas loop 210, and the vacuum chamber 336. Figures 6-8 In one embodiment, the working gas source 110 and the precooler gas source 112 are connected to the cryoablation system 100 at the proximal end of the handle 102, while the vacuum source 114 is connected to the cryoablation system near the distal end of the handle. However, the three sources can be connected along any suitable portion of the handle 102.

[0109] Additionally or alternatively, the cryoablation system may include two, three, four, or more precooler gas sources. Alternatively, the cryoablation system 100 may not include a separate precooler gas source. In such embodiments, the cryoablation system may have a multi-stage cooling system in which the pressure of the working gas is reduced in multiple stages (e.g., two, three, or four stages). For example, the working gas pressure may be reduced in two stages, such as from approximately 4000 psi to approximately 2000 psi in the first stage and from approximately 2000 psi to approximately 500 psi in the second stage.

[0110] In various embodiments, the precooler gas supply circuit 212 passes through and exists within the handle 102. When referring to the portion of the precooler gas supply circuit 212 that passes through the handle 102, the term "handle portion of the precooler gas supply circuit" will be used. Similarly, the vacuum chamber 336 and the working gas circuit 210 have portions that pass through the handle 102, and these portions will be referred to herein as the "handle portion of the vacuum chamber" and the "handle portion of the working gas circuit," respectively.

[0111] In various embodiments, the handle 102 may include a handle portion of the precooler gas supply circuit 212, a handle portion of the vacuum chamber 336, and a handle portion of the working gas circuit 210. In various embodiments, the precooler gas supply circuit 212 is configured to supply precooler gas from a high-pressure cryogenic gas source (in this case, precooler gas source 112) to the handle 102. Figure 2 As shown and described, the precooler gas circuit may include a precooler Joule-Thomson throttling orifice located in the precooler gas expansion zone 222.

[0112] Shaft 104 may include an isolation region 105 along its proximal length. This isolation region 105 may include the axial portion of the vacuum chamber 336 and the isolation portion of the working gas circuit 210. Figure 4 As best shown, the vacuum chamber 336 surrounds and is isolated from the isolation portion of the working gas circuit 210. This shaft may include a working gas expansion chamber 106 located distal to the isolation region 105. (As shown) Figure 5 As shown in the best embodiment, the working gas expansion chamber 106 includes the expansion portion of the working gas circuit 210.

[0113] like Figures 2-3 As shown and described, the working gas circuit 210 is configured to supply working gas from a high-pressure cryogenic gas source (in this case, working gas source 110) to the working gas expansion chamber 106. The working gas circuit includes a working gas Joule-Thomson throttle orifice 332 at the working gas expansion chamber 106.

[0114] In various embodiments, shaft 104 can be inserted into handle 102 and securely attached to the handle via shaft-handle connector 103. A proximal end of shaft 104 is configured to connect to shaft-handle connector 103, and shaft-handle connector is configured to removably attach the proximal end of shaft 104 to a distal end of handle 102. In the context of this application, when two components are removably attached, a first component (e.g., the handle of a cryoablation system) can be attached to and / or detached from a second component (e.g., the shaft of a cryoablation system) without damaging the first component. In some examples, the first component can be attached to and / or detached from the second component without damaging either component. In other examples, the second component can be attached to and / or detached from the first component while intentionally plastically deforming certain parts of the second component without damaging the first component.

[0115] In the context of the cryoablation system 100, the shaft-handle connector 103 allows the shaft 104 to be removed from the handle 102 without damaging the handle. The shaft-handle connector 103 also allows the precooler gas supply circuit 212, the working gas circuit 210, and the vacuum chamber 336 to remain isolated from each other within the handle 102 when the shaft 104 is removed from the handle. This configuration improves the efficiency of the cryoablation system 100 because in many applications, the shaft 104 must be replaced each time a cryoablation procedure is performed, but the handle 102 can be reused. The shaft-handle connector 103 enables the user of the cryoablation system 100 to remove the first shaft 104 from the handle 102 of the cryoablation system and replace the first shaft with a second shaft (not shown).

[0116] exist Figures 6-8 In the example, shaft 104 is permanently attached to shaft-handle connector 103, and shaft-handle connector 103 is removably attached to handle 102 via a fastening device (e.g., fastener 638). Shaft 104 can be removed from handle 102 by releasing the fastening device and removing shaft-handle connector 103 from handle 102. Alternatively or additionally, shaft-handle connector 103 can be removably attached to shaft 104, such that shaft can be removed from handle 102 without removing shaft-handle connector 103.

[0117] In an alternative embodiment, the reusable handle 102 is configured to consume the shaft 104. For example, the shaft 104 is connected to the handle 102 by clamping the handle onto the shaft (e.g., by using one or more Yor-Lok fittings, etc.). In such embodiments, the handle 102 is restrained onto the shaft 104 such that the shaft is consumed by the handle (e.g., partial plastic deformation of the shaft, and the shaft is a disposable component), but the handle is not damaged and is suitable for reuse. The Yor-Lok fitting is a compression fitting designed to handle high-pressure fluid connections. The body and nut are provided with two collars or sleeves located at the front and rear of the body and nut to form an hermetically sealed connection.

[0118] exist Figures 6-8 In some embodiments, the inner surface 844 of the handle is configured to form a seal around the outer surface 846 of the shaft-handle connector. In some embodiments, the shaft-handle connector 103 may include one or more O-rings 840 (or another sealing device) configured to enhance the seal between the handle 102 and the shaft-handle connector. Additionally or alternatively, the handle 102 may include one or more O-rings (or another sealing device) configured to enhance the seal between the handle 102 and the shaft-handle connector 103. Additionally or alternatively, the handle 102 may include one or more metal or plastic components coupled with one or more O-rings (or another sealing device) configured to seal via plastic deformation of the material between the handle 102 and the shaft-handle connector 103.

[0119] The cryoablation system 100 may also include a fixing device to fix the shaft-handle connector 103 to the handle. Figures 6-8 In the example, the shaft-handle connector 103 includes a fastener 638. The fastener 638 is configured to rest on a connector protrusion 848 of the shaft-handle connector 103 and to be secured to a handle protrusion 850 of the handle 102. In one embodiment, both the fastener 638 and the handle protrusion 850 may be threaded, and the fastener 638 may be screwed into the handle protrusion 850 to securely and removably attach the shaft-handle connector 103 to the handle 102. It should be noted that any other fastening device configured to securely and removably attach the shaft-handle connector 103 to the handle 102 may be used.

[0120] like Figure 8As best shown, the shaft-handle connector 103 includes a vacuum chamber connector portion 847. The shaft-handle connector 103 may define one or more vacuum openings 854 in fluid communication with the vacuum chamber connector portion 847. The vacuum openings 854 are configured to connect to a vacuum chamber handle portion 849, which is connected to a vacuum source 114. In some embodiments, the vacuum chamber handle portion 849 extends along the length of the handle 102. In such embodiments, the vacuum chamber provides a protective barrier between the handle 102 and the operator of the cryoablation system to isolate the precooler gas expanding in the handle. Alternatively, the vacuum chamber handle portion 849 may terminate near a distal end of the handle, extending along the length of the handle 102.

[0121] In various embodiments, the vacuum chamber connector portion 847 is also in fluid communication with a vacuum chamber 336 extending through the isolation region 105 of the shaft 104. By fluidly connecting a vacuum source to the shaft 104 via the shaft-handle connector 103, a vacuum can be drawn along the length of the isolation region 105 of the shaft 104 while maintaining isolation from the precooler gas supply circuit 212 and the working gas circuit 210. In some embodiments, throughout the cryoablation procedure, the vacuum drawn along the isolation region 105 of the shaft 104 provides a protective barrier between the outer surface of the shaft 104 and the patient to isolate the cryocooled working gas. In some embodiments, throughout the cryoablation procedure, the combination of the insulating material construction and the vacuum drawn along the isolation region 105 of the shaft 104 provides a further protective barrier between the outer surface of the shaft 104 and the patient to isolate the cryocooled working gas.

[0122] In some embodiments, the vacuum source 114 is an active vacuum. For example, the vacuum source 114 may be a vacuum pump, etc. The vacuum pump may be operatively connected to the vacuum chamber 336. The vacuum chamber is configured to prevent heat transfer by creating a low-pressure environment in an isolated region of the shaft, between the return pipe 326 and the isolated shaft 328. Alternatively, the vacuum source may be a passive vacuum, such as a vacuum sleeve, etc. A vacuum sleeve typically consists of two layers of material (inner and outer layers) separated by a vacuum or low-pressure gap.

[0123] In various embodiments, the shaft-handle connector 103 defines one or more working gas openings 856 through which a return portion of the working gas circuit 210 extends between the handle 102 and the shaft-handle connector 103. The working gas openings 856 are configured to connect to a working gas exhaust port 118. The working gas openings 856 are also in fluid communication with an insulating portion of the working gas circuit 210, such that the working gas, after expanding in the expansion chamber 106 of the shaft 104, returns through the shaft and then exits through the working gas exhaust port 118 via the working gas openings 856 in the shaft-handle connector 103. In some embodiments, the working gas exhaust port 118 may be connected to a conduit that transports the working gas exhaust back to the control console or another location within the operating room, where the working gas exhaust is appropriately released into the surrounding environment. In another embodiment, the working gas outlet 118 may be connected to a conduit that carries the working gas exhaust through a chamber surrounding the conduit containing precooler gas, such that the working gas exhaust cools the precooler gas to achieve increased thermal efficiency.

[0124] In various embodiments, the shaft-handle connector 103 may include a valve 842. Figures 6-8 In the example, valve 842 may be a check valve and includes a spring 843. However, other suitable types of valves may also be used. In various embodiments, valve 842 may have an open state and a closed state, in which the working gas circuit 210 flows from handle 102 to shaft 104 through conduit 868 of shaft-handle connector 103, and in the closed state, the working gas circuit 210 cannot flow from handle 102 to shaft 104 through conduit 868 of shaft-handle connector. In various embodiments, valve 842 is configured to switch from the open state to the closed state when shaft 104 and shaft-handle connector 103 are removed from handle 102. This feature is configured to prevent working gas leakage from handle 102 when shaft 104 is replaced. Figure 8 The diagram shows the valve 842 in an open state, in which the spring 843 is depressed, thus opening the valve via a linear movement caused by tightening the fastener 638 of the shaft-handle connector 103 onto the handle protrusion 850 of the handle 102. In various embodiments, the valve 842 moves to the open state by securing the shaft-handle connector 103 into a sealing engagement with the handle 102.

[0125] Shaft-handle connector ( Figures 9-11 )

[0126] Now for reference Figures 9-11 Various views of the shaft-handle connector are shown here. Figure 9 This is a schematic side view of a shaft-handle connector according to various embodiments herein. Figure 10This is a cross-sectional view of a shaft-handle connector according to various embodiments herein. Figure 11 This is an exploded view of the shaft-handle connector according to various embodiments herein.

[0127] In various embodiments, the shaft-handle connector 103 may include a first connector 1058 and a second connector 1060. The first connector 1058 is configured to attach to the second connector 1060 by any suitable means. In some embodiments, the first connector 1058 is configured to be permanently attached to the second connector 1060 by means of interference fit or the like. In some embodiments, the first connector 1058 is configured to be removably attached to the second connector 1060. For example, the first connector 1058 and the second connector 1060 may be threaded, and the second connector 1060 may be screwed into the first connector 1058. Alternatively, the first connector 1058 and the second connector 1060 may include one or more removable fittings for attaching the first connector 1058 to the second connector 1060.

[0128] In various embodiments, the second connector 1060 may define a protrusion 1062. The protrusion 1062 of the second connector 1060 is configured to extend within a cavity 1064 defined within the first connector 1058. The second connector 1060 may also include a second cavity 1066. In various embodiments, the second cavity 1066 may be in fluid communication with a conduit 868. For example, the fluid conduit 868 may form part of the second cavity 1066. The fluid conduit 868 is configured to receive working gas from the handle 102 and deliver the working gas to the shaft 104 via a closed supply tube 324. The fluid conduit 868 may include an internal space 1067 surrounded by an inner surface 1069. In various embodiments, the inner surface 1069 is configured to seal to the outer surface of the supply tube near its proximal end. The sealing area between the supply tube 324 and the inner surface 1069 of the fluid conduit 868 is... Figure 12 As shown in the image.

[0129] The connector may also define a first fitting 1052 at its distal end. The connector may also define a second fitting 1063. The second fitting 1063 may form part of or extend from a protrusion 1062 of the second connector 1060 and be disposed within a cavity 1064 of the first connector 1058. In various embodiments, the first fitting 1052 and the second fitting 1063 are each configured to attach to a portion of the shaft 104. The protrusion 1062 includes an inner surface 1070, and the inner surface 1070 is configured to seal the outer surface of the return tube near its proximal end. The sealing area between the return tube 326 and the inner surface 1070 of the protrusion 1062 is... Figure 12As shown in the figure. In various embodiments, the shaft-handle connector 103 is made of any suitable one or more materials, such as flexible metal, polymer, composite material, etc. In one embodiment, the shaft-handle connector 103 is made of nitinol (NiTi), stainless steel, etc.

[0130] Catheter assembly ( Figures 12-13 )

[0131] Now for reference Figures 12-13 Various views of the catheter assembly are shown here. Figure 12 This is a schematic diagram of a catheter assembly according to various embodiments herein. Figure 13 This is a cross-sectional view of a catheter assembly according to various embodiments herein. In various embodiments, catheter assembly 1264 may include a shaft 104 of cryoablation system 100 and a shaft-handle connector 103. In some embodiments, catheter assembly 1264 includes components of the cryoablation system that are replaced each time a cryoablation procedure is performed.

[0132] In various embodiments, shaft 104 may include a supply tube 324 extending along a portion of the shaft's length. The supply tube may be surrounded by a return tube 326 along a portion of its length. The return tube 326 may be surrounded by an isolation shaft 328 along an isolation region 105 of the shaft. Figures 12-13 In the example, supply tube 324 terminates at its furthest point in the proximal direction 639 of the cryoablation system 100, and isolation shaft 328 terminates at its furthest point in the distal direction 637 of the cryoablation system. In an alternative configuration, the individual layers of shaft 104 may terminate at the same location along the cryoablation system 100.

[0133] In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the insulating shaft 328. Figures 12-13 In the example, the first tubular fitting 1052 of the shaft-handle connector 103 is configured to seal around the proximal end of the insulating shaft 328. In some embodiments, the insulating shaft 328 may be permanently attached to the shaft-handle connector 103. For example, the proximal portion of the insulating shaft 328 may be fitted inside the shaft-handle connector 103, and a portion 1366 of the first tubular fitting 1052 may be melted and reflowed (or coupled by another suitable means) onto the outer surface of the insulating shaft 328 to form a seal between the insulating shaft 328 and the shaft-handle connector 103. In an alternative embodiment, the insulating shaft 328 may be removably attached to the shaft-handle connector 103 using any suitable fastening device.

[0134] In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the return pipe 326. For example... Figure 13As illustrated in the example, the inner surface 1070 of the second fitting 1063 and / or the protrusion 1062 of the shaft-handle connector 103 are configured to seal around the proximal end of the return tube 326. In some embodiments, the return tube 326 may be permanently attached to the shaft-handle connector 103. For example, the proximal portion of the return tube 326 may be fitted inside the shaft-handle connector 103, and a portion 1368 of the second fitting 1063 may be melted and reflowed (or coupled by another suitable means) onto the outer surface of the return tube 326 to form a seal between the return tube 326 and the shaft-handle connector 103. In an alternative embodiment, the return tube 326 may be removably attached to the shaft-handle connector 103 using any suitable fastening device.

[0135] In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the supply tube 324. Figures 12-13 In the example, the fluid conduit 868 of the shaft-handle connector 103 (which may form part of the second cavity 1066) is configured to seal around the proximal end of the supply tube 324. The fluid conduit 868 may include an internal space 1067 surrounded by an inner surface 1069, and the inner surface 1069 is configured to seal the outer surface of the supply tube 324. In some embodiments, the supply tube 324 may be permanently connected to the shaft-handle connector 103. For example, the proximal portion of the supply tube 324 may be fitted inside the shaft-handle connector and may be permanently coupled (e.g., by brazing, soldering, etc.) to the fluid conduit 868 of the shaft-handle connector 103. In alternative embodiments, the supply tube 324 may be removably connected to the shaft-handle connector 103 using any suitable fastening device.

[0136] Operating instructions for cryoablation system ( Figure 14 )

[0137] This document considers many different methods, including but not limited to manufacturing methods and usage methods. Based on the various embodiments described herein, aspects of the operation of the system / device described elsewhere herein can be performed as one or more methods of operation.

[0138] Now for reference Figure 14This document describes a method 1400 for operating a cryoablation system. Method 1400 may include step 1402 of providing the cryoablation system. In various embodiments, the cryoablation system may include a precooler gas circuit, a working gas circuit isolated from the precooler gas circuit, and a vacuum chamber isolated from both the working gas circuit and the precooler gas circuit. The cryoablation system may also include a first conduit assembly. The first conduit assembly may include a first shaft and a first shaft-handle connector. The first shaft may include a first working gas expansion chamber, and the cryoablation system may also include a handle having a handle portion for the precooler gas circuit and a handle portion for the working gas circuit isolated from the handle portion of the precooler gas circuit. In various embodiments, a proximal end of the first shaft is configured to connect to the first shaft-handle connector.

[0139] Method 1400 may include step 1404 of detaching the first conduit assembly from the handle. In various embodiments, a first shaft-handle connector removably attaches the proximal end of the first shaft to the distal end of the handle. In one embodiment, the first shaft can be removably attached to the handle via the first shaft-handle connector, allowing the first shaft to be removed from the handle without damaging it. Furthermore, the first conduit assembly can be removed from the handle without impeding the handle's ability to isolate the precooler gas circuit, working gas circuit, and vacuum chamber from each other when the conduit assembly is attached to the handle.

[0140] exist Figures 6-8 In one example, the shaft-handle connector 103 may include a fastener 638, and the shaft 104 can be removed from the handle 102 by releasing the fastener (e.g., by loosening the fastener from the handle) and removing the shaft from the handle. In various embodiments, step 1404 of removing the catheter assembly 1264 from the handle 102 may be performed after each use of the cryoablation system, such as when a cryoablation procedure is performed on a patient.

[0141] Method 1400 may include step 1406 of attaching a second conduit assembly to a handle. In various embodiments, the second conduit assembly includes a second shaft and a second shaft-handle connector. The second shaft may include a second working gas expansion chamber. In various embodiments, step 1406 may include attaching the second shaft to the second shaft-handle to form the second conduit assembly and removably attaching the second conduit assembly to the handle. While the second conduit assembly can be assembled and attached to the handle using any suitable sequence of steps, an exemplary sequence will be described in detail below.

[0142] exist Figures 12-13In one example, the shaft-handle connector 103 may include a first connector 1058 and a second connector 1060. A protrusion 1062 of the second connector 1060 is configured to extend within a cavity 1064 defined within the first connector 1058. In such embodiments, to attach the shaft 104 to the shaft-handle connector 103, an isolating shaft 328 may first be coupled to the first connector 1058. For example, a proximal portion of the isolating shaft 328 may be fitted inside the shaft-handle connector 103, and a portion 1366 of the first fitting 1052 may be fused (or coupled in another suitable manner) to the outer surface of the isolating shaft 328 to form a seal between the isolating shaft 328 and the shaft-handle connector 103.

[0143] After the isolating shaft 328 is attached to the first connector 1058, the return pipe 326 and the supply pipe 324 can be connected to the second connector 1060, and the first connector 1058 can be attached to the second connector 1060. In one embodiment, the proximal portion of the return pipe 326 can be fitted inside the shaft-handle connector 103, and a portion 1368 of the second fitting 1063 can be fused (or connected by another suitable means) to the outer surface of the return pipe 326 to form a seal between the return pipe 326 and the shaft-handle connector 103. In one embodiment, the fluid passage 868 of the shaft-handle connector 103 is configured to seal around the proximal end of the supply pipe 324. The first connector 1058 can then be securely attached to the second connector 1060 by any suitable means (e.g., interference fit, etc.).

[0144] After assembling the second conduit assembly, the second conduit assembly can be removably attached to the distal end of the handle and secured to the handle using fasteners or the like.

[0145] The concepts described herein can be applied to and used in conjunction with the cryoablation systems and components described in the following four U.S. non-provisional patent applications filed on May 22, 2024, which are incorporated herein by reference in their entirety: U.S. non-provisional patent application No. 18 / 671,489 entitled “Cryoablation Catheter Shaft Construction”; U.S. non-provisional patent application No. 18 / 671,627 entitled “Safety Devices for Cryoablation Probe”; U.S. non-provisional patent application No. 18 / 671,727 entitled “Delivery Systems for Cryoablation Device”; and U.S. non-provisional patent application No. 18 / 671,742 entitled “Distal Tip Structure for Cryoablation Probe”.

[0146] It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise. It should also be noted that the term “or” is generally used to include the meaning of “and / or” unless the context clearly indicates otherwise.

[0147] It should also be noted that, as used in this specification and the appended claims, the phrase “configuration” describes a system, device, or other structure that is constructed or configured to perform a particular task or employ a particular configuration. The phrase “configuration” may be used interchangeably with other similar phrases, such as arrangement and configuration, construction and arrangement, construction, manufacture and arrangement, etc.

[0148] All publications and patent applications in this specification reflect the ordinary level of skill in the art to which this invention pertains. All publications and patent applications are incorporated herein by reference to the extent that each individual publication or patent application is expressly and individually indicated to be incorporated herein by reference.

[0149] As used in this article, the range of values ​​described by endpoints should include all values ​​contained within that range (e.g., 2 to 8 includes 2.1, 2.8, 5.3, 7, etc.).

[0150] The headings used herein are for compliance with 37 CFR 1.77 or otherwise to provide organizational clues. These headings should not be construed as limiting or restricting any invention described in any claim that may be formed by this disclosure. For example, although a heading may refer to “technical field,” such a claim should not be limited by the wording chosen to describe the so-called technical field under that heading. Furthermore, the description of the technology in the “Background Art” section is not an admission that the technology is prior art to any invention in this disclosure. The “Summary of the Invention” section is also not intended to limit the invention set forth in the published claims.

[0151] The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, these embodiments were chosen and described to enable those skilled in the art to recognize and understand these principles and practices. Accordingly, various aspects have been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications can be made while remaining within the spirit and scope of this document.

Claims

1. A cryoablation system, comprising: Working gas circuit; A vacuum chamber that is isolated from the working gas circuit; A shaft, the shaft comprising along its length: An isolation region extending proximal to the axis, the isolation region comprising an isolation portion of the vacuum chamber shaft and an isolation portion of the working gas circuit, wherein the vacuum chamber shaft portion surrounds and is isolated from the isolation portion of the working gas circuit; and A working gas expansion chamber located on the distal side of the isolation area, wherein the working gas expansion chamber includes the expansion portion of the working gas circuit; and A shaft-handle connector, wherein a proximal end of the shaft is connected to the shaft-handle connector, wherein the shaft-handle connector is configured to removably attach the proximal end of the shaft to a distal end of the handle, wherein the shaft-handle connector further includes: A working gas connector structure is configured to form a sealed connection with the working gas supply passage and the working gas discharge passage in the handle; A vacuum connector structure configured to form a sealed connection with the vacuum chamber portion of the handle; and The shaft-handle connector includes a connector portion of the vacuum chamber that is isolated from the connector portion of the working gas circuit.

2. The cryoablation system according to any one of claims 1 and 3-13, wherein, The shaft includes a supply tube extending along a portion of the length of the shaft, wherein the supply tube is surrounded by a return tube along a portion of the length of the supply tube, wherein the return tube is surrounded by an isolation shaft along an isolation region of the shaft, wherein the shaft-handle connector is configured to form a seal around the outer surface of the isolation shaft.

3. The cryoablation system according to any one of claims 1-2 and 4-13, wherein, The shaft-handle connector includes a first piece and a second piece, wherein a protrusion of the second piece is configured to extend within a cavity defined within the first piece.

4. The cryoablation system according to any one of claims 1-3 and 5-13, wherein, The inner surface of the protrusion of the second piece of the shaft-handle connector is configured to form a seal around the outer surface of the return tube.

5. The cryoablation system according to any one of claims 1-4 and 6-13, wherein, The second connector of the shaft-handle connector includes an internal space, and the inner surface of the internal space is configured to form a seal around the outer surface of the supply tube.

6. The cryoablation system according to any one of claims 1-5 and 7-13, wherein, The inner surface of the handle is configured to form a seal around the outer surface of the shaft-handle connector.

7. The cryoablation system according to any one of claims 1-6 and 8-13, wherein, The second component of the shaft-handle connector includes an internal space, and the inner surface of the internal space is configured to form a seal around the outer surface of the supply tube.

8. The cryoablation system according to any one of claims 1-7 and 9-13, wherein, The shaft-handle connector includes a connector portion of the vacuum chamber, wherein the shaft-handle connector defines one or more openings that are in fluid communication with the connector portion of the vacuum chamber and are configured to connect to the vacuum chamber portion of the handle.

9. The cryoablation system according to any one of claims 1-8 and 10-13, wherein, The shaft-handle connector defines one or more openings through which a reflux portion of the working gas circuit extends between the handle and the shaft-handle connector.

10. The cryoablation system according to any one of claims 1-9 and 11-13, wherein, The working gas circuit is configured to supply working gas from a high-pressure cryogenic gas source to the working gas expansion chamber. The working gas circuit includes a working gas Joule-Thomson throttling orifice, through which the working gas enters the working gas expansion chamber.

11. The cryoablation system according to any one of claims 1-10 and 12-13, further comprising a handle, the handle including a handle portion of the vacuum chamber and a handle portion of the working gas circuit.

12. The cryoablation system according to any one of claims 1-11 and 13, wherein, The shaft can be removed from the handle without compromising the handle portion's ability to isolate the working gas circuit and the handle portion's ability to isolate the vacuum chamber.

13. The cryoablation system according to any one of claims 1-12, wherein, The cryoablation system further includes a precooler gas circuit isolated from the working gas circuit and the vacuum circuit, wherein the handle includes a handle portion of the precooler gas circuit, wherein the precooler gas circuit is configured to supply precooler gas from a high-pressure cryogenic gas source to the handle, the precooler gas circuit includes a precooler Joule-Thomson orifice, and the precooler gas enters the precooler expansion chamber at the precooler Joule-Thomson orifice.

14. A method of operating a cryoablation system, comprising: Provide a cryoablation system, the cryoablation system comprising: Working gas circuit; A first catheter assembly, the first catheter assembly including a first shaft and a first shaft-handle connector, the first shaft including a first working gas expansion chamber; The handle includes a handle portion of the working gas circuit; and Wherein, the proximal end of the first shaft is connected to the first shaft-handle connector, wherein the first shaft-handle connector removably attaches the proximal end of the first shaft to the distal end of the handle; Remove the first catheter assembly from the handle; The second conduit assembly is attached to the handle, wherein the second conduit assembly includes a second shaft and a second shaft-handle connector, the second shaft including a second working gas expansion chamber, wherein the proximal end of the second shaft is connected to the second shaft-handle connector, and wherein the second shaft-handle connector is configured to removably attach the proximal end of the second shaft to the distal end of the handle.

15. The method according to claim 14, wherein, The working gas circuit is configured to supply working gas from a high-pressure cryogenic gas source to the working gas expansion chamber. The working gas circuit includes a working gas Joule-Thomson throttling orifice, through which the working gas enters the working gas expansion chamber.

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