Multiple gas circuit connector and method for cryoablation systems

Abstract

In one embodiment, the 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. The cryoablation system may include a shaft having an adiabatic region and a working gas expansion chamber distal to the adiabatic region. The cryoablation system may further include a handle and a shaft-handle connector, the proximal end of the shaft being connected to the shaft-handle connector, the shaft-handle connector being configured to detachably attach the proximal end of the shaft to the distal end of the handle.

Description

[Technical Field]

[0001] Embodiments of the present specification relate to cryoablation systems, and more specifically, to a cryoablation system provided with a removable shaft. [Background Art]

[0002] During cryosurgery, a surgeon can ablate a target region of a patient's anatomy by placing one or more cryoprobes to freeze and thaw tissue. In one example, the cryoprobe uses the Joule-Thomson effect to achieve cooling or heating of the probe tip. In such cases, the low-temperature fluid in the cryoablation probe expands from high pressure to low pressure, thereby cooling the tip of the device to a temperature corresponding to or lower than that required for cryoablation in tissue near the tip. Heat transfer between the expanded low-temperature fluid and the outer wall of the cryoprobe forms an ice ball in tissue around the tip, after which cryoablation of the tissue is performed. [Summary of the Invention]

[0003] In a first aspect, a cryoablation system may comprise a precooler gas circuit, a working gas circuit, and a vacuum chamber. The cryoablation system may comprise a shaft having an insulating region along a proximal length of the shaft. The insulating region may comprise a vacuum chamber shaft portion and an insulating portion of the working gas circuit, wherein the vacuum chamber shaft portion surrounds the insulating portion of the working gas circuit and may be isolated from the insulating portion of the working gas circuit. The shaft may comprise a working gas expansion chamber distal to the insulating region, the working gas expansion chamber comprising an expansion portion of the working gas circuit. The cryoablation system may comprise a handle having a vacuum chamber handle portion and a working gas circuit handle portion. The cryoablation system may further comprise 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 the handle.

[0004] In a second embodiment, in addition to or as an alternative to one or more of the embodiments described above, the shaft may include a supply pipe extending along a portion of the length of the shaft, the supply pipe being surrounded by a return pipe along a portion of the length of the supply pipe, the return pipe being surrounded by an insulating shaft along an insulating region of the shaft, and the shaft-handle connector may be configured to form a seal around the outer surface of the insulating shaft.

[0005] In a third embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the shaft-handle connector may include a first connector component and a second connector component, wherein the projection of the second connector component may be configured to extend into a cavity formed within the first connector component.

[0006] In a fourth embodiment, in addition to or as an alternative to one or more of the preceding or succeeding embodiments, the inner surface of the projection of the second connector component of the shaft-handle connector may be configured to form a seal around the outer surface of the return tube.

[0007] In a fifth embodiment, in addition to or as an alternative to one or more of the embodiments described above, the second connector component of the shaft-handle connector may include an internal space, the inner surface of which is configured to form a seal around the outer surface of the supply pipe.

[0008] In a sixth embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the inner surface of the handle may be configured to form a seal around the outer surface of the shaft-handle connector.

[0009] In the seventh aspect, in addition to or as an alternative to one or more of the preceding or following aspects, the shaft can be removed from the handle without impairing the handle's ability to isolate the handle portion of the working gas circuit and the handle portion of the vacuum chamber.

[0010] In the eighth aspect, in addition to or as an alternative to one or more of the preceding or following aspects, the shaft-handle connector may include a connector portion of the vacuum chamber, and the shaft-handle connector may be configured to form one or more openings that are in fluid communication with the connector portion of the vacuum chamber and to be connected to the vacuum chamber portion of the handle.

[0011] In the ninth aspect, in addition to or as an alternative to one or more of the preceding or subsequent aspects, the shaft-handle connector forms one or more openings between the handle and the shaft-handle connector through which the return portion of the operating gas circuit passes.

[0012] In a tenth embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the refrigeration ablation system further comprises a precooler gas circuit isolated from the working gas circuit and the vacuum circuit, and the handle includes a handle portion of the precooler gas circuit. The precooler gas circuit is 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 a position where the precooler gas enters the precooler expansion chamber.

[0013] In the eleventh embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the working gas circuit is configured to supply working gas from a high-pressure cryogenic gas source to a working gas expansion chamber, and the working gas circuit may include a working gas Joule-Thomson orifice at a position where the working gas enters the working gas expansion chamber.

[0014] In a twelfth embodiment, the cryoablation system includes a working gas circuit and a vacuum chamber isolated from the working gas circuit. The cryoablation system includes a shaft having an insulated region along its proximal length, the insulated region having a vacuum chamber shaft portion and an insulated portion of the working gas circuit, the vacuum chamber shaft portion may surround and isolate from the insulated portion of the working gas circuit. The shaft may include a working gas expansion chamber distal to the insulated region, which includes an expansion portion of the working gas circuit. The cryoablation system may include a shaft-handle connector. The proximal end of the shaft may be connected to a shaft-handle connector, which may be configured to detachably attach the proximal end of the shaft to the distal end of a handle. The shaft-handle connector further includes a working gas connector structure configured to form a sealed connection to a working gas supply passage and a working gas discharge passage within the handle, a vacuum connector structure configured to form a sealed connection to 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.

[0015] In a thirteenth embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the shaft may include a supply pipe extending along a portion of the length of the shaft, the supply pipe being surrounded by a return pipe along a portion of the length of the supply pipe, the return pipe being surrounded by an insulating shaft along an insulating region of the shaft, and the shaft-handle connector may be configured to form a seal around the outer surface of the insulating shaft.

[0016] In a fourteenth embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the shaft-handle connector may include a first component and a second component, wherein a projection of the second component may be configured to extend into a cavity formed within the first component.

[0017] In a 15th embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the inner surface of the projection of the second component of the shaft-handle connector may be configured to form a seal around the outer surface of the return tube.

[0018] In a sixteenth embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the second component of the shaft-handle connector may include an internal space, the inner surface of which is configured to form a seal around the outer surface of the supply pipe.

[0019] In the 17th embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the shaft-handle connector may include a connector portion of a vacuum chamber, and the shaft-handle connector may be configured to form one or more openings that are in fluid communication with the connector portion of the vacuum chamber and to be connected to the vacuum chamber portion of the handle.

[0020] In the 18th embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the shaft-handle connector forms one or more openings between the handle and the shaft-handle connector through which the return portion of the operating gas circuit passes.

[0021] In the 19th embodiment, in addition to or as an alternative to one or more of the embodiments described above or below, the working gas circuit is configured to supply working gas from a high-pressure cryogenic gas source to a working gas expansion chamber, and the working gas circuit may include a working gas Joule-Thomson orifice at a position where the working gas enters the working gas expansion chamber.

[0022] In a 20th embodiment, a method for operating a cryoablation system may include the step of preparing 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 of the working gas circuit. The proximal end of the first shaft is connected to a first shaft-handle connector, which detachably attaches the proximal end of the first shaft to the distal end of the handle. The method may include the step of removing the first catheter assembly from the handle. The method may include the step of 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, and the proximal end of the second shaft is connected to the second shaft-handle connector. A second shaft-to-handle connector may be configured to detachably attach the proximal end of the second shaft to the distal end of the handle.

[0023] This summary is a brief overview of some of the teachings of this application and is not intended to be an exclusive or exhaustive treatment of the subject matter. Further details are found in the detailed description and the attached claims. Each aspect may be better understood in conjunction with the drawings. Other aspects may become apparent to those skilled in the art by reading and understanding the following detailed description and by viewing the drawings which form part thereof, but each aspect should not be constrained. The scope of this disclosure is defined by the attached claims and their legal equivalents. [Brief explanation of the drawing]

[0024] The details can be understood more clearly by referring to the following drawings. [Figure 1]It is a schematic diagram of a cryoablation system according to various embodiments of the present disclosure. [Figure 2] It is a schematic diagram of a part of a cryoablation system according to various embodiments of the present disclosure. [Figure 3] It is a schematic diagram of a part of a cryoablation shaft according to various embodiments of the present disclosure. [Figure 4] It is a cross-sectional view of the shaft of Fig. 3, taken along section 4-4 of Fig. 3, according to various embodiments of the present disclosure. [Figure 5] It is a cross-sectional view of the shaft of Fig. 3, taken along section 5-5 of Fig. 3, according to various embodiments of the present disclosure. [Figure 6] It is a schematic diagram of a cryoablation system according to various embodiments of the present specification. [Figure 7] It is a cross-sectional view of the cryoablation system of Fig. 6, taken along line 7-7 of Fig. 6, according to various embodiments of the present specification. [Figure 8] It is an enlarged view of the cryoablation system of Fig. 7, focusing on detail 8 of Fig. 7, according to various embodiments of the present specification. [Figure 9] It is a side view of a shaft-handle connector according to various embodiments of the present specification. [Figure 10] It is a cross-sectional view of a shaft-handle connector according to various embodiments of the present specification. [Figure 11] It is an exploded side view of a shaft-handle connector according to various embodiments of the present specification. [Figure 12] It is a side view of a catheter assembly according to various embodiments of the present specification. [Figure 13] It is a cross-sectional view of a catheter assembly according to various embodiments of the present specification. [Figure 14] It is a flowchart illustrating a method for using a cryoablation system according to various embodiments of the present specification. Description of Embodiments

[0025] Each embodiment may take various modifications and alternative forms, but details of each embodiment are shown by drawing examples and described in detail below. The scope of this disclosure is not limited to the specific embodiments described. Rather, it is intended to encompass the modifications, equivalents, and alternative forms that fall within the spirit and scope of this disclosure.

[0026] Cryoablation, also known as cryotherapy or cryosurgery, is a medical procedure that involves using extremely low temperatures to destroy or remove abnormal or diseased tissue. Cryoablation is used in various medical fields, including oncology (cancer treatment), cardiology (cardiac treatment), and dermatology (skin treatment). In cryoablation, a shaft is inserted into or near the target tissue. This shaft contains a cryogenic substance, such as liquid nitrogen or argon gas, which is used to rapidly cool the tissue to extreme temperatures. The extremely low temperatures cause ice crystals to form inside the cells, which leads to cell damage and ultimately cell death.

[0027] In some applications, cryoablation systems use a rigid shaft to deliver cryogenic material to a target anatomical structure. While rigid shafts are generally more robust, they limit access to the patient's anatomical structure. Some cryoablation systems may be useful for ablating lesions in the biliary system or other hard-to-access areas of human anatomy. Flexible cryoablation shafts can be implemented to access such anatomical features. However, flexible shafts are more difficult to hold high-pressure gases.

[0028] In most cases, after a cryoablation procedure, the catheter of the cryoablation system is considered a single-use component and is designed to be removed and replaced. Other parts of the cryoablation system, such as the handle and control console, should, if possible, be reused across multiple cryoablation procedures.

[0029] This disclosure is directed to a cryoablation system having a removable catheter assembly. The catheter assembly may include a shaft and a shaft-handle connector. The shaft may be detachably attached to a handle using the shaft-handle connector. The shaft-handle connector allows for the replacement of the shaft of the cryoablation system while keeping multiple fluid circuits (e.g., precooler gas, working gas, and vacuum) isolated from each other within the handle.

[0030] The concepts described herein may be applied in connection with the cryoablation systems described in U.S. Patent Application Publication No. 2021 / 00045793, entitled “Dual Stage Cryocooler,” and U.S. Patent Application Publication No. 2021 / 00045794, entitled “Flexible Cryoprobe,” both filed on August 14, 2020, both of which are incorporated herein by reference in their entirety.

[0031] Referring to Figure 1, schematic diagrams of cryoablation systems according to various embodiments of the present disclosure are shown. 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 using a shaft-to-handle connector 103. In various embodiments, the shaft 104 and the shaft-to-handle connector 103 of the cryoablation system 100 may form a catheter assembly. In some embodiments, the catheter 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.

[0032] These three sources correspond to three independent circuits within the refrigeration ablation system 100: namely, the precooler, the working fluid, and the 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 refrigeration ablation system 100, and the vacuum source 114 is connected near the distal end of the handle, adjacent to the shaft-to-handle connector 103. The refrigeration ablation system may further include a precooler gas exhaust port 116 and a working gas exhaust port 118 connected to the handle 102. In various embodiments, the shaft-to-handle connector 103 functions as a manifold, maintaining each fluid circuit isolated from one another.

[0033] In some embodiments, the cryoablation system 100 includes a console 117. The console may be used to control the system. The console may be electrically connected to the handle and the cryoablation assembly, and may also be in fluid communication. In some embodiments, the working fluid source 110, the precooler fluid source 112, and the vacuum source 114 may all be connectable to the console 117 of the cryoablation system 100 using conduits. In some embodiments, the precooler gas exhaust port 116, the working gas exhaust port 118, or both may be connectable to conduits that return the exhaust to the console 117 or another location in the treatment room, so that the exhaust is released into the ambient environment at an appropriate location. Various supply and exhaust ports may be arranged in any suitable configuration at predetermined locations along the handle 102. Thus, the arrangement in Figure 1 is only one example of a suitable configuration.

[0034] Examples of the specifications and functions of each of these circuits are provided in the following paragraphs. However, the specific fluid and pressure values ​​are for illustrative purposes only, and other configurations are possible. In one embodiment, the pre-cooler circuit may contain pressurized argon at 24.1 megapascals (MPa). The pre-cooler circuit can cool the incoming working fluid and operate within 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 thaws an ice ball. The working fluid circuit can operate within the handle, within the insulated portion or region of the shaft, and within the expansion chamber of the shaft. In one embodiment, the active vacuum can maintain a vacuum of 6.67 pascals (Pa) or less. The active vacuum can insulate the shaft. The active vacuum can operate within the handle and within the insulated region of the shaft.

[0035] In various embodiments, the working fluid circuit extends inside both the handle 102 and the shaft 104 of the cryoablation system 100 and carries the fluid that generates and thaws the ice ball. The term “fluid circuit” as used throughout this application may be replaced in various embodiments with a gas circuit, liquid circuit, fluid chamber, gas chamber, or liquid chamber. The term “fluid” as used throughout this application may be replaced in various embodiments with a gas or liquid. The term “gas circuit” is also used throughout this application and may be replaced in various embodiments with a fluid circuit, liquid circuit, fluid chamber, gas chamber, or liquid chamber. The term “gas” is used throughout and may be replaced in various embodiments with a fluid or liquid.

[0036] During ablation (freezing cycle), argon at 12.4 MPa is circulated through the probe to create an ice ball within the patient's body surrounding 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 working fluid high-pressure flow may be 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 or higher. In some embodiments, the pressure of the working fluid high-pressure flow may be 55.2 MPa, 34.5 MPa, 20.7 MPa, 18.6 MPa, 16.5 MPa, 14.5 MPa, or 12.4 MPa or lower. In some embodiments, the pressure of the working fluid high-pressure flow may be in the range of 6.9 MPa to 41.4 MPa, 8.3 MPa to 27.6 MPa, 9.7 MPa to 16.5 MPa, 11.0 MPa to 14.5 MPa, or about 12.4 MPa. Therefore, in embodiments where the working fluid is a cooling fluid, the temperature of the working fluid in the expansion chamber 106 may be about 190 Kelvin. In some embodiments, the temperature of the working fluid may be 250 Kelvin, 200 Kelvin, 150 Kelvin, or 100 Kelvin or less, or within a range of any of these.

[0037] In various embodiments, the pre-cooler circuit is completely housed within the handle 102. In various embodiments, the pre-cooler circuit is located within the system console 117. In various embodiments, the pre-cooler circuit is located within a portion of the catheter located immediately proximal to the handle. In various embodiments, the pre-cooler circuit is located within a portion of the catheter located immediately distal to the handle. In various embodiments, the pre-cooler circuit operates using argon or any other suitable cooling fluid. In some embodiments, the high-pressure flow of the pre-cooler fluid may be at a higher pressure than the high-pressure flow of the working fluid. The pre-cooler fluid may be supplied at a pressure higher than, for example, about 13.8 MPa. In some embodiments, the pressure of the pre-cooler fluid may be 10.3 MPa, 13.8 MPa, 17.2 MPa, 20.7 MPa, or 24.1 MPa or higher. In some embodiments, the pressure of the pre-cooler fluid may be 31.0 MPa, 29.3 MPa, 25.9 MPa, or 24.1 MPa or lower. In some embodiments, the pressure of the precooler fluid may be in the range of 10.3 MPa to 31.0 MPa, 13.8 MPa to 29.3 MPa, 17.2 MPa to 27.6 MPa, 20.7 MPa to 25.9 MPa, or about 24.1 MPa.

[0038] In some embodiments, the outer surface of the shaft 104 can be insulated from the inner surface of the shaft. In various embodiments, a vacuum circuit or vacuum chamber extends both within the handle 102 and within the insulated region 105 of the shaft 104. Throughout the cryoablation procedure, a vacuum is actively drawn along the insulated region 105 of the shaft 104, providing a protective barrier between the outer surface of the shaft 104 and the patient. In alternative embodiments, shaft insulation can be achieved by circulating a fluid, gas, or heating fluid throughout the shaft, or by electrically heating a portion of the shaft. In alternative embodiments, shaft insulation can be achieved by housing a non-circulating fluid or gas within the insulated shaft.

[0039] The shaft 104 may be any appropriate length that allows it to reach the target anatomical structure of the subject. In some embodiments, the shaft length may be 20 cm, 38 cm, 55 cm, 72 cm, or 90 cm or more. In some embodiments, the shaft length may be 150 cm, 135 cm, 120 cm, 105 cm, or 90 cm or less. In some embodiments, the shaft length may be in the range of 20 cm to 150 cm, 38 cm to 135 cm, 55 cm to 120 cm, 72 cm to 105 cm, or about 90 cm.

[0040] In various embodiments, specific portions of the 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 is flexible enough to form a curve with a desired radius of curvature. For example, the shaft may be flexible enough to form a curve with a minimum radius of curvature of 30 mm, 20 mm, 10 mm, or 5 mm or less.

[0041] In various embodiments, the shaft 104 may include an insulated region 105 and an expansion chamber 106. The insulated region 105 defines the portion of the shaft 104 that is insulated by the vacuum chamber. The expansion chamber 106 is the portion of the shaft 104 that is not insulated by the vacuum and defines the portion where the ice ball is generated. In various embodiments, the flexible shaft transports a high-pressure working fluid from the handle 102 to the expansion chamber 106, where it undergoes Joule-Thomson expansion and the corresponding temperature change. The working fluid travels down the flexible shaft, through the handle, and is discharged into the atmosphere from the console, or enters the handle and is discharged from the handle.

[0042] The distal end of the shaft may terminate with a distal working tip 108. During use, the distal working tip 108 is positioned in the patient's body, surrounded by tissue, and possibly to ablate the tissue at cryogenic temperatures. The distal working tip 108 may, advantageously, be configured to puncture tissue in some examples. For example, the distal working tip 108 may include a sharp tip, such as a trocar tip. Alternatively, the distal working tip 108 may not have a sharp tip. In some embodiments, the distal working tip 108 may be a non-traumatic tip designed to cause minimal tissue damage. In some embodiments, the distal working tip 108 may include an operating port configured for aspiration, delivery of therapeutic drugs, and delivery of other devices, including but not limited to guidewires, imaging catheters, sensing devices, biopsy devices, balloons, and stents.

[0043] [Handle equipped with a pre-cooling circuit (Figure 2)] Referring to Figure 2, schematic diagrams of some of the refrigeration ablation systems according to various embodiments of the present disclosure are shown. In some embodiments, the refrigeration ablation system 100 may include a working fluid source 110 connected to a working fluid circuit and a pre-cooler fluid source 112 connected to a pre-cooler fluid circuit. The working fluid circuit may include a working fluid supply conduit 210 for transporting a high-pressure flow of working fluid from the working fluid source 110 to the distal end of the shaft 104 (not shown in this figure). The working fluid circuit may also include a working fluid return conduit (not shown in this figure) for returning a low-pressure flow of working fluid from the distal end of the shaft to the base of the handle 102.

[0044] The precooler fluid circuit may include a precooler supply circuit 212 that terminates at a precooler Joule-Thomson orifice 223 and delivers a high-pressure flow of precooler fluid from a precooler fluid source 112 to the precooler fluid expansion region 222 within the handle 102. The precooler fluid circuit may also include a precooler return conduit (indicated by arrow 213). The precooler return conduit may be configured to deliver precooler fluid away from the precooler fluid expansion region 222 back to the base of the handle 102. The precooler return conduit may be housed together with the precooler supply circuit 212 and extend back to the control console and gas manifold.

[0045] In various embodiments, a pre-cooler fluid circuit can facilitate heat exchange between the working fluid and the pre-cooler fluid. For example, in embodiments where the working fluid cools during expansion to cryogenically ablate the tissue around the distal working tip 108, a pre-cooler fluid circuit can be used to pre-cool the high-pressure flow of the working fluid. In various embodiments, the working fluid supply conduit 210 may include a first heat exchanger 216. The first heat exchanger 216 can facilitate heat exchange between the high-pressure flow of the working fluid in the working fluid supply conduit 210 and the low-pressure flow of the pre-cooler fluid in the pre-cooler return conduit.

[0046] In various embodiments, the precooler supply conduit 212 may include a second heat exchanger 218 that enables heat exchange (e.g., regenerative heat exchange) between a high-pressure flow of precooler fluid and a low-pressure flow of precooler fluid. In some embodiments, the precooler fluid may be a cooling fluid. In such embodiments, heat can be removed from the high-pressure flow of precooler fluid by regenerative heat exchange between the high-pressure flow of precooler fluid and the low-pressure flow of precooler fluid. Thus, the second heat exchanger 218 can facilitate the precooling of the high-pressure flow of precooler fluid.

[0047] In various embodiments, the high-pressure precooler fluid flowing out of the second heat exchanger 218 continues to flow through the precooler supply conduit 212 into the precooler fluid expansion region 222. In the precooler fluid expansion region, which is entirely contained within the handle 102, the precooler supply conduit 212 terminates at a Joule-Thomson orifice. The high-pressure precooler fluid flow may expand at or downstream of the Joule-Thomson orifice within the precooler fluid expansion region 222. This rapid decrease in pressure causes a corresponding decrease in temperature. The precooler fluid expansion region 222 may be in fluid communication with a precooler return conduit to transport the expanded low-pressure precooler fluid flow (for example, to discharge into the atmosphere if the precooler fluid circuit is open, or to return to the precooler fluid source if the precooler fluid circuit is closed). After expanding in the Joule-Thomson orifice, the cooled precooler fluid returns through the handle 102 in the annular space between the core tube 215 and the outer surface of the handle 102. As the precooler fluid passes through the precooler return conduit, it cools the working fluid in the first heat exchanger 216.

[0048] The working fluid circuit 210 may further include a third heat exchanger 220 in the shaft 104 of the refrigeration ablation system configured to perform heat exchange (e.g., regenerative heat exchange) between the high-pressure flow of working fluid in the working fluid supply circuit 210 and the low-pressure flow of working fluid (not shown in this figure) returning through the shaft 104.

[0049] [Details of the distal tip and expansion chamber (Figure 3)] Referring to Figure 3, schematic diagrams of some of the cryoablation shafts according to various embodiments of the present disclosure are shown. In various embodiments, the shaft includes an insulated region 105 and an expansion chamber 106. In various embodiments, the insulated region 105 of the shaft 104 includes a supply pipe 324 located within a return pipe 326 located within an insulated shaft 328. A concentric shaft structure is designed to isolate the working fluid circuit 210 and the vacuum chamber 336 from each other.

[0050] In various embodiments, the high-pressure working fluid flows down the supply pipe 324 after exiting the handle 102. When the working fluid reaches the working fluid expansion chamber 106, the supply pipe 324 terminates at the Joule-Thomson orifice 332 or the distal outlet 332. The high-pressure working fluid can expand in the Joule-Thomson orifice 332 within the expansion chamber 106, or downstream thereof. This rapid decrease in pressure causes a corresponding decrease in temperature. Heat transfer between the expanded working fluid and the outer wall of the expansion chamber 106 causes an ice ball to form in the tissue around the tip 108, resulting in cryoablation of the tissue.

[0051] The expansion chamber 106 may be in fluid communication with a working fluid return conduit (defined by the annular space between the supply pipe 324 and the inner surface of the return pipe 326 of the expansion chamber) to transport the expanded low-pressure flow of working fluid (for example, to discharge it into the atmosphere if the working fluid circuit is open, or to return it to the working fluid source if the working fluid circuit is closed). As the working fluid passes through the working fluid return conduit, it cools the working fluid input flow in the third heat exchanger 220 (Figure 2).

[0052] In various embodiments, the working fluid is a cooling fluid and / or cooling gas (e.g., nitrogen, air, argon, krypton, xenon, N2O, CO2, CF4). In this case, the pressure of the high-pressure flow of the working fluid may be such that expansion through the Joule-Thomson orifice 332 cools the working fluid to a temperature at which it ablates the tissue surrounding the expansion chamber 106 at cryogenic temperatures. In certain embodiments, the pressure of the high-pressure flow of the working fluid upstream of the Joule-Thomson orifice 332 may be about 6.9 MPa to about 13.8 MPa (e.g., about 12.4 MPa). Therefore, in embodiments where the working fluid is a cooling fluid, the temperature of the working fluid after expansion exiting the Joule-Thomson orifice 332 may be 150 Kelvin, 160 Kelvin, 170 Kelvin, 180 Kelvin, 190 Kelvin, or 200 Kelvin or higher, or within a range of any of these values.

[0053] The cryoablation system 100 may be designed so that the outermost surface of the shaft does not cause thermal damage to non-target structures. In various embodiments, ice ball formation is limited to the expansion chamber 106 of the shaft 104, which may also be referred to as the operating region of the apparatus. Selective ice ball formation is achieved by vacuuming through the insulated region 105 of the shaft 104. In various embodiments, the cryoablation system 100 may be configured to establish a vacuum communication between the shaft 104 and the vacuum source 114.

[0054] Referring again to Figure 1, the cryoablation system 100 may be configured to connect to a vacuum source 114 at the handle 102. In various embodiments, the vacuum source 114 is configured to evacuate along the length of the insulated region 105 of the shaft 104. In one embodiment, the entire insulated region 105 of the shaft 104 is evacuated between the outer diameter of the return pipe 326 and the inner diameter of the insulated shaft 328.

[0055] In various embodiments, the vacuum source 114 is configured to evacuate within at least a portion of the handle 102. Such a configuration can insulate the handle 102 and protect the operator of the refrigeration ablation system from cryogenic exhaust gases. In some embodiments, the vacuum source 114 is connected to the handle 102, and the space between the supply pipe 324 and the return pipe 326 can be evacuated by evacuating the inside of the handle 102, by fluid communication between the shaft 104 and the handle 102. In other embodiments, the vacuum source 114 is connected directly to the shaft 104, for example, using a T-fitting along the length of the shaft 104.

[0056] To provide thermal insulation along the insulated region 105 of shaft 104, the wall of the flexible shaft is a double wall (return tube surrounded by the insulated shaft) with a small gap between the return tube 326 and the insulated shaft 328. By preventing convective heat transfer by vacuuming the space between the return tube and the insulated shaft, the temperature of the working fluid does not cause ablation of healthy non-target patient tissue along the insulated region of the shaft or induce uncontrolled apoptosis / necrosis. Sufficient insulation is achieved by actively evacuating the air in the gap and maintaining a vacuum of about 0.05 Torr. However, depending on the configuration of the cryoablation system, other vacuum pressures may be appropriate. In some embodiments, a support filament 330 is wound along the outer diameter of the return tube 326. One choice of filament material is a polymer such as polyetheretherketone (PEEK). The filament can prevent direct contact between the outer surface of the return tube and the inner surface of the insulated shaft. The filament 330 minimizes heat conduction between the inner shaft and the insulated shaft. Instead of the filament 330, other alternatives may be used, such as an extruded tube / co-extruded shape or other features positioned on a shaft.

[0057] In some embodiments, the shaft may not include a filament. In such embodiments, the return tube 326 and the insulated shaft 328 are selected to have material properties sufficient to minimize heat conduction between the inner shaft and the insulated shaft.

[0058] The joint 334 is located at the junction of the insulating region 105 and the expansion chamber 106. This joint can seal the vacuum layer. [Cross section, dimensions, and material of a flexible shaft (Figure 4)] Referring to Figure 4, a cross-sectional view of the shaft of Figure 3 obtained along section 4-4 according to various embodiments of the present disclosure is shown. In various embodiments, the insulated region 105 of the shaft 104 includes a supply pipe 324 concentrically located within a return pipe 326 concentrically located within an insulated shaft 328. The insulated region 105 may include the shaft portion of the vacuum chamber 336 and the insulated portion of the working gas circuit 210. In various embodiments, the vacuum chamber 336 surrounds and isolates the insulated portion of the working gas circuit 210 from the insulated portion.

[0059] In various embodiments, after exiting the handle 102, the high-pressure working fluid flows distally through the adiabatic region of the shaft via the supply pipe 324. After cooling and expanding in the expansion chamber 106, the working fluid returns proximal through the adiabatic region 105 of the shaft 104 in the annular space between the supply pipe 324 and the return pipe 326.

[0060] In various embodiments, the material and dimensions of each layer of the shaft 104 may be selected to have a degree of flexibility sufficient to allow the shaft to bend about its longitudinal axis at the operating temperature of the device.

[0061] In various embodiments, the supply tube 324, which may also be referred to herein as a capillary tube, is made of any suitable material such as a flexible metal, polymer, or composite material. In one embodiment, the supply tube 324 is made of nitinol (NiTi), stainless steel, or the like.

[0062] In some embodiments, the inner diameter of the supply pipe 324 may be 0.30 mm, 0.35 mm, 0.40 mm, or 0.45 mm or more. In some embodiments, the inner diameter of the supply pipe 324 may be 0.60 mm, 0.55 mm, 0.50 mm, or 0.45 mm or less. In some embodiments, the diameter of the supply pipe 324 may be in the range of 0.30 mm to 0.60 mm, in the range of 0.35 mm to 0.55 mm, in the range of 0.40 mm to 0.50 mm, or about 0.45 mm.

[0063] In some embodiments, the outer diameter of the supply pipe 324 may be 0.38 mm, 0.43 mm, 0.48 mm, 0.53 mm, or 0.58 mm or more. In some embodiments, this outer diameter may be 0.78 mm, 0.73 mm, 0.68 mm, 0.63 mm, or 0.58 mm or less. In some embodiments, this outer diameter may be in the range of 0.38 mm to 0.78 mm, in the range of 0.43 mm to 0.73 mm, in the range of 0.48 mm to 0.68 mm, in the range of 0.53 mm to 0.63 mm, or about 0.58 mm.

[0064] In some embodiments, the thickness of the supply pipe 324 may be 0.10 mm, 0.11 mm, 0.12 mm, 0.14 mm, or 0.15 mm or more. In some embodiments, the thickness of the supply pipe 324 may be 0.20 mm, 0.19 mm, 0.18 mm, 0.16 mm, or 0.15 mm or less. In some embodiments, the thickness of the supply pipe 324 may be in the range of 0.10 mm to 0.20 mm, in the range of 0.11 mm to 0.19 mm, in the range of 0.12 mm to 0.18 mm, in the range of 0.14 mm to 0.16 mm, or about 0.15 mm.

[0065] In various embodiments, the return tube 326 is composed of any suitable material or combination of materials, such as a flexible metal or polymer. In various embodiments, the return tube 326 may be made of polyimide, fluorinated ethylene propylene (FEP), Teflon®, etc. In one embodiment, the return tube 326 is formed from a polyimide material to have high gas impermeability over a wide temperature range, thereby allowing a vacuum to be maintained on the outside while accommodating the working fluid inside. In certain examples, the return tube 326 is made from a braided-reinforced polyimide tube to enhance gas impermeability, burst strength, and flexibility. In some embodiments, the return tube 326 is formed from a single layer of material. In some embodiments, the return tube 326 may be formed from two or more material layers selected to optimize the performance of the shaft 104. These material layers may be joined to each other using any suitable one or more techniques, such as adhesives or reflow processes.

[0066] In some embodiments, the outer diameter of the return pipe 326 may be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, or 1.4 mm or more. In some embodiments, the outer diameter of the return pipe 326 may be 1.8 mm, 1.7 mm, 1.6 mm, 1.5 mm, or 1.4 mm or less. In some embodiments, the outer diameter of the return pipe 326 may be in the range of 1.0 mm to 1.8 mm, 1.1 mm to 1.7 mm, 1.2 mm to 1.6 mm, 1.3 mm to 1.5 mm, or about 1.4 mm.

[0067] In some embodiments, the inner diameter of the return pipe 326 may be 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, or 1.3 mm or more. In some embodiments, the inner diameter of the return pipe 326 may be 1.7 mm, 1.6 mm, 1.5 mm, 1.4 mm, or 1.3 mm or less. In some embodiments, the inner diameter of the return pipe 326 may be in the range of 0.9 mm to 1.7 mm, in the range of 1.0 mm to 1.6 mm, in the range of 1.1 mm to 1.5 mm, in the range of 1.2 mm to 1.4 mm, or about 1.3 mm.

[0068] In some embodiments, the thickness of the return tube 326 may be 0.10 mm, 0.11 mm, 0.12 mm, 0.14 mm, or 0.15 mm or more. In some embodiments, the thickness of the return tube 326 may be 0.20 mm, 0.19 mm, 0.18 mm, 0.16 mm, or 0.15 mm or less. In some embodiments, the thickness of the return tube 326 may be in the range of 0.10 mm to 0.20 mm, in the range of 0.11 mm to 0.19 mm, in the range of 0.12 mm to 0.18 mm, in the range of 0.14 mm to 0.16 mm, or about 0.15 mm.

[0069] In various embodiments, the insulated shaft 328 is made of any suitable material such as a flexible metal or polymer. In various embodiments, the insulated shaft 328 is made of polyimide, fluorinated ethylene propylene (FEP), Teflon®, etc. In certain embodiments, the insulated shaft 328 may contain polytetrafluoroethylene (PTFE) and / or one or more polyether block amides (trade name Pebax®, hereinafter known as "Pebax").

[0070] In some embodiments, the insulated shaft 328 is formed from a single layer of material. In some embodiments, the insulated shaft 328 may be formed from two or more layers of material selected to optimize the performance of the shaft 104. These layers of material may be joined to each other using any suitable one or more techniques, such as adhesives or reflow processes.

[0071] In one embodiment, the insulated shaft may be formed using a braided-reinforced polyimide tube coated with an outer layer of Pebax. Such a three-layer structure allows a high vacuum to be maintained between the return tube and the insulated shaft without the insulated shaft 328 collapsing on the return tube 326.

[0072] In some embodiments, the outer diameter of the insulating shaft 328 may be 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, or 1.8 mm or more. In some embodiments, the outer diameter of the insulating shaft may be 2.2 mm, 2.1 mm, 2.0 mm, 1.9 mm, or 1.8 mm or less. In some embodiments, the outer diameter of the insulating shaft may be in the range of 1.3 mm to 2.3 mm, 1.4 mm to 2.1 mm, 1.5 mm to 2.0 mm, 1.6 mm to 1.9 mm, or about 1.8 mm.

[0073] In some embodiments, the inner diameter of the insulating shaft 328 may be 1.0 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.6 mm or more. In some embodiments, the inner diameter of the insulating shaft 328 may be 2.2 mm, 2.0 mm, 1.9 mm, 1.8 mm, or 1.6 mm or less. In some embodiments, the inner diameter of the insulating shaft 328 may be in the range of 1.0 mm to 2.2 mm, 1.2 mm to 2.0 mm, 1.3 mm to 1.9 mm, 1.4 mm to 1.8 mm, or about 1.6 mm.

[0074] In some embodiments, the thickness of the insulating shaft 328 may be 0.10 mm, 0.11 mm, 0.12 mm, 0.14 mm, or 0.15 mm or more. In some embodiments, the thickness of the insulating shaft 328 may be 0.20 mm, 0.19 mm, 0.18 mm, 0.16 mm, or 0.15 mm or less. In some embodiments, the thickness of the insulating shaft 328 may be in the range of 0.10 mm to 0.20 mm, in the range of 0.11 mm to 0.19 mm, in the range of 0.12 mm to 0.18 mm, in the range of 0.14 mm to 0.16 mm, or about 0.15 mm.

[0075] In some embodiments, PEEK filaments 330 are wound around the return tube 326. The PEEK filaments 330 may have a pitch of 0.5 mm, 1.0 mm, 1.5 mm, or 2.0 mm or more, or a pitch within a range of any of these values. Alternatively, the filaments may be multiple separate parts mounted along the return tube 326. The PEEK filaments 330 maintain their coaxial arrangement by preventing direct contact between the return tube 326 and the insulated shaft 328. In some embodiments, an adhesive (e.g., LOCTITE®) is applied to the filaments at the ends of the return tube 326 and the insulated shaft 328 to attach the PEEK filaments 330. In various embodiments, the winding of the PEEK filaments is configured to minimize or prevent conductive heat transfer from the return tube to the insulated shaft. In alternative embodiments, other insulating polymers such as stretched PTFE (ePTFE) and nylon may be used as substitutes for the PEEK filaments.

[0076] In some embodiments, the diameter of the PEEK filament 330 may be 0.002 mm, 0.004 mm, or 0.005 mm or more. In some embodiments, the diameter of the PEEK filament 330 may be 0.007 mm, 0.006 mm, or 0.005 mm or less. In some embodiments, the diameter of the PEEK filament 330 may be in the range of 0.002 mm to 0.007 mm, in the range of 0.004 mm to 0.006 mm, or about 0.005 mm.

[0077] [Shaft inside the expansion chamber (Figure 5)] Referring to Figure 5, a cross-sectional view of the shaft of Figure 3 obtained along cross-section 5-5 according to various embodiments of the present disclosure is shown. The cross-sectional view of Figure 5 shows the expansion chamber 106 of the shaft 104. In various embodiments, the expansion chamber 106 is located distal to the adiabatic region 105 along the shaft 104. The expansion chamber 106 may include the expansion portion of the working fluid circuit 210.

[0078] In various embodiments, the high-pressure working fluid flows down the supply pipe 324 after exiting the handle 102. After cooling and expanding in the expansion chamber 106, the working fluid returns downward through the expansion chamber 106 in the annular space between the supply pipe 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 patient tissue through optimization of parameters such as wall thickness and material.

[0079] In various embodiments, the expansion chamber 106 is made of any suitable material or combination of materials, such as a flexible metal or polymer. 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 an extension of the return tube 326 in the insulated region 105 of the shaft 104. Alternatively, the expansion chamber is a separate component from the return tube 326 and can be joined to the shaft 104 using any suitable joining and / or fitting, such as reflow soldering, adhesive bonding, soldering, or any other suitable mechanical joining process capable of withstanding cryogenic pressure and temperature.

[0080] In some embodiments, the expansion chamber 106 is formed from a single material layer. In some embodiments, the expansion chamber 106 is formed from two or more material layers. These material layers can be joined to each other using any suitable one or more techniques, such as adhesives or reflow processes.

[0081] In some embodiments, the outer diameter of the expansion chamber 106 may be 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, or 1.7 mm or more. In some embodiments, the outer diameter of the expansion chamber 106 may be 2.1 mm, 2.0 mm, 1.9 mm, 1.8 mm, or 1.7 mm or less. In some embodiments, the outer diameter of the expansion chamber 106 may be in the range of 1.3 mm to 2.1 mm, 1.4 mm to 2.0 mm, 1.5 mm to 1.9 mm, 1.6 mm to 1.8 mm, or about 1.7 mm.

[0082] In some embodiments, the inner diameter of the expansion chamber 106 may be 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, or 1.4 mm or more. In some embodiments, the inner diameter of the expansion chamber 106 may be 1.8 mm, 1.7 mm, 1.6 mm, 1.5 mm, or 1.4 mm or less. In some embodiments, the inner diameter of the expansion chamber 106 may be in the range of 1.0 mm to 1.8 mm, 1.1 mm to 1.7 mm, 1.2 mm to 1.6 mm, 1.3 mm to 1.5 mm, or about 1.4 mm.

[0083] In some embodiments, the wall thickness of the expansion chamber 106 may be 0.20 mm, 0.22 mm, 0.25 mm, 0.28 mm, or 0.30 mm or more. In some embodiments, the wall thickness of the expansion chamber 106 may be 0.40 mm, 0.38 mm, 0.35 mm, 0.32 mm, or 0.30 mm or less. In some embodiments, the wall thickness of the expansion chamber 106 may be in the range of 0.20 mm to 0.40 mm, in the range of 0.22 mm to 0.38 mm, in the range of 0.25 mm to 0.35 mm, in the range of 0.28 mm to 0.32 mm, or about 0.30 mm.

[0084] [Cryoablation System (Figures 6-8)] Referring to Figures 6 to 8, various diagrams of the cryoablation system are shown. Figure 6 is a schematic diagram of a cryoablation system according to various embodiments of this specification. Figure 7 is a cross-sectional view of the cryoablation system of Figure 6, according to various embodiments of this specification, viewed in the plane of the paper along line 7-7 in Figure 6. Figure 8 is an enlarged view of detail 8 of Figure 7, according to various embodiments of this specification, of the cryoablation system of Figure 7. Referring to the drawings, arrows have been added to indicate the distal direction 637 and the proximal direction 639.

[0085] In various embodiments, the cryoablation system 100 may include a handle 102 and a shaft 104. In some embodiments, the cryoablation system 100 may include a working gas source 110, a pre-cooler gas source 112, and a vacuum source 114, which are connectable to the cryoablation system 100. The three sources correspond to three independent circuits in the cryoablation system 100, namely the pre-cooler gas supply circuit 212, the working gas circuit 210, and the vacuum chamber 336. In the embodiments shown in Figures 6 to 8, the working gas source 110 and the pre-cooler gas source 112 are connected to the cryoablation system 100 at the proximal end of the handle 102, and the vacuum source 114 is connected to the cryoablation system near the distal end of the handle. However, the three sources may be connected along any preferred position on the handle 102.

[0086] Additionally, or alternatively, the refrigeration ablation system may include two, three, four, or more precooler gas sources. Alternatively, the refrigeration ablation system 100 may not include an independent precooler gas source. In such embodiments, the refrigeration ablation system may have a multi-stage cooling system in which the working gas pressure is reduced in multiple stages, such as two, three, or four stages. For example, the working gas pressure may be reduced in two stages, such as from about 4000 psi (27.5 MPa) to about 2000 psi (13.8 MPa) in the first stage, and from about 2000 psi (13.8 MPa) to about 500 psi (3.5 MPa) in the second stage.

[0087] In various embodiments, the precooler gas supply circuit 212 extends through and resides within the handle 102. The term “handle portion of the precooler gas supply circuit” is used to refer to the portion of the precooler gas supply circuit 212 that passes through the handle 102. Similarly, the vacuum chamber 336 and the working gas circuit 210 also have portions that pass through the handle 102, which are referred to herein as the “handle portion of the vacuum chamber” and the “handle portion of the working gas circuit,” respectively.

[0088] 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 to the handle 102 from a high-pressure cryogenic gas source (in this case, the precooler gas source 112). As shown and described in Figure 2, the precooler gas circuit may include a precooler Joule-Thomson orifice in the precooler gas expansion region 222.

[0089] The shaft 104 may include an adiabatic region 105 along its proximal length. The adiabatic region 105 may include the shaft portion of the vacuum chamber 336 and the adiabatic portion of the working gas circuit 210. As best shown in Figure 4, the vacuum chamber 336 surrounds and isolates the adiabatic portion of the working gas circuit 210. The shaft may include a working gas expansion chamber 106 distal to the adiabatic region 105. As best shown in Figure 5, the working gas expansion chamber 106 includes the expansion portion of the working gas circuit 210.

[0090] As shown and explained in Figures 2 and 3, 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, and the working gas circuit includes a working gas Joule-Thomson orifice 332 in the working gas expansion chamber 106.

[0091] In various embodiments, the shaft 104 is insertable into the handle 102 and can be securely attached to the handle by a shaft-handle connector 103. The proximal end of the shaft 104 is configured to connect to the shaft-handle connector 103, which is configured to detachably attach the proximal end of the shaft 104 to the distal end of the handle 102. In the context of this application, detachable attachment of two components means that a first component (e.g., the handle of a cryoablation system) can be attached to and / or removed 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 removed from the second component without damaging either the first or second component. In other examples, the second component can be attached to and / or removed from the first component without damaging the first component, while intentionally plastically deforming certain components of the second component.

[0092] 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 even when the shaft 104 is removed from the handle. Such a configuration can improve the efficiency of the cryoablation system 100 because, in many applications, the shaft 104 is replaced each time a cryoablation procedure is performed, while the handle 102 can be reused. The shaft-handle connector 103 allows the user of the cryoablation system 100 to remove the first shaft 104 from the handle 102 of the cryoablation system and replace it with a second shaft (not shown).

[0093] In the examples shown in Figures 6 to 8, the shaft 104 is permanently attached to the shaft-handle connector 103, which is detachably attached to the handle 102 by fastening means (e.g., fasteners 638). The shaft 104 can be removed from the handle 102 by releasing the fastening means and removing the shaft-handle connector 103 from the handle 102. Additionally or alternatively, the shaft-handle connector 103 can also be detachably connected to the shaft 104, in which case the shaft can be removed from the handle 102 without removing the shaft-handle connector 103.

[0094] 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 (for example, by using one or more Yor-Lok fittings). In such an embodiment, the handle 102 is fixed to the shaft 104 and the shaft is consumed by the handle (for example, a portion of the shaft is plastically deformed and the shaft is sacrificed), but the handle is not damaged and is suitable for reuse. A Yor-Lok fitting is a compression fitting designed to accommodate high-pressure fluid connections. The body and nut are supplied together with two ferrules or sleeves positioned before and after the body and nut to form an airtight seal.

[0095] In the embodiments shown in Figures 6 to 8, the inner surface of the handle 844 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 other sealing means) 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 other sealing means) 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 parts configured, in combination with one or more O-rings (or other sealing means), to form a seal between the handle 102 and the shaft-handle connector 103 via plastic deformation of the material.

[0096] The cryoablation system 100 may further include fastening means for securing the shaft-handle connector 103 to the handle. In the example shown in Figures 6-8, the shaft-handle connector 103 includes a fastener 638. The fastener 638 is mounted on the connector projection 848 of the shaft-handle connector 103 and is configured to be fastened to the handle projection 850 of the handle 102. In one embodiment, both the fastener 638 and the handle projection 850 may be threaded, and the fastener 638 can be screwed into the handle projection 850 to securely and detachably attach the shaft-handle connector 103 to the handle 102. Note that any other fastening means configured to securely and detachably attach the shaft-handle connector 103 to the handle 102 may be used.

[0097] As best shown in Figure 8, the shaft-handle connector 103 includes a vacuum chamber connector portion 847. The shaft-handle connector 103 can form one or more vacuum openings 854 that are 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 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 from precooler gases expanding within the handle. Instead of extending along the length of the handle 102, the vacuum chamber handle portion 849 may terminate near the distal end of the handle.

[0098] In various embodiments, the vacuum chamber connector portion 847 is also in fluid communication with a vacuum chamber 336 that extends through the insulated region 105 of the shaft 104. By fluidly connecting the vacuum source to the shaft 104 via the shaft-handle connector 103, a vacuum can be drawn along the length of the insulated 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, drawing a vacuum along the insulated region 105 of the shaft 104 throughout the cryoablation procedure provides a protective barrier between the outer surface of the shaft 104 and the patient from the cryogenically cooled working gas. In some embodiments, combining an insulating material structure with a vacuum drawn along the insulated region 105 of the shaft 104 throughout the cryoablation procedure provides an additional protective barrier between the outer surface of the shaft 104 and the patient from the cryogenically cooled working gas.

[0099] In some embodiments, the vacuum source 114 is an active vacuum. For example, the vacuum source 114 may be a vacuum pump. The vacuum pump may be operably connected to the vacuum chamber 336. The vacuum chamber is configured to prevent heat transfer by creating a low-pressure environment between the return pipe 326 and the insulated shaft 328 in the insulated region of the shaft. Alternatively, the vacuum source may be a passive vacuum, such as a vacuum sleeve. A vacuum sleeve often consists of two material layers separated by a vacuum or low-pressure gap, namely an inner layer and an outer layer.

[0100] In various embodiments, the shaft-handle connector 103 forms one or more working gas openings 856 between the handle 102 and the shaft-handle connector 103 through which the return portion of the working gas circuit 210 passes. The working gas openings 856 are configured to be connected to a working gas exhaust section 118. The working gas openings 856 are also in fluid communication with the insulated portion of the working gas circuit 210, and after expanding in the expansion chamber 106 of the shaft 104, the working gas returns through the shaft and is then discharged from the working gas exhaust section 118 via the working gas openings 856 of the shaft-handle connector 103. In some embodiments, the working gas exhaust section 118 is connected to a conduit that returns the working gas exhaust to a console or another location in the treatment room, and is exhausted into the ambient environment at an appropriate location. In another embodiment, the working gas exhaust section 118 is connected to a conduit that carries the working gas exhaust through a chamber surrounding a conduit containing a precooler gas, so that the working gas exhaust cools the precooler gas and improves thermal efficiency.

[0101] In various embodiments, the shaft-handle connector 103 may include a valve 842. In the examples of Figures 6 to 8, the valve 842 may be a check valve and may include a spring 843. However, other suitable types of valves may be implemented. In various embodiments, the valve 842 may have an open state in which the working gas circuit 210 flows from the handle 102 through the conduit 868 of the shaft-handle connector 103 to the shaft 104, and a closed state in which the working gas circuit 210 cannot flow from the handle 102 through the conduit 868 of the shaft-handle connector to the shaft 104. In various embodiments, the valve 842 is configured to switch from the open state to the closed state when the shaft 104 and the shaft-handle connector 103 are removed from the handle 102. Such a mechanism is configured to prevent leakage of working gas from the handle 102 when the shaft 104 is replaced. Figure 8 shows the valve 842 in the open state, in which the spring 843 is compressed, and the valve is opened by the linear motion generated by screwing the fastener 638 of the shaft-handle connector 103 onto the handle projection 850 of the handle 102. In various embodiments, the valve 842 moves to the open state by the operation of sealing and fixing the shaft-handle connector 103 to the handle 102.

[0102] [Shaft-Handle Connector (Figures 9-11)] Referring here to Figures 9 to 11, various diagrams of the shaft-handle connector are shown. Figure 9 is a schematic side view of a shaft-handle connector according to various embodiments of this specification. Figure 10 is a cross-sectional view of a shaft-handle connector according to various embodiments of this specification. Figure 11 is an exploded view of a shaft-handle connector according to various embodiments of this specification.

[0103] In various embodiments, the shaft-handle connector 103 may include a first connector component 1058 and a second connector component 1060. The first connector component 1058 is configured to be attached to the second connector component 1060 by any suitable means. In some embodiments, the first connector component 1058 is configured to be permanently attached to the second connector component 1060 by means of a crimp fit or the like. In some embodiments, the first connector component 1058 is configured to be removablely attached to the second connector component 1060. For example, the first connector component 1058 and the second connector component 1060 may be threaded, and the second connector component 1060 may be screwed into the first connector component 1058. Alternatively, the first connector component 1058 and the second connector component 1060 may include one or more removable fixtures for attaching the first connector component 1058 to the second connector component 1060.

[0104] In various embodiments, the second connector component 1060 may form a projection 1062. The projection 1062 of the second connector component 1060 is configured to extend into a cavity 1064 formed within the first connector component 1058. The second connector component 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 by surrounding the supply pipe 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 against the outer surface of the supply pipe near the proximal end of the supply pipe. The sealing area between the supply pipe 324 and the inner surface 1069 of the fluid conduit 868 is shown in Figure 12.

[0105] The connector may have a first pipe fitting 1052 formed at its distal end. The connector may also have a second pipe fitting 1063 formed. The second pipe fitting 1063 may form part of the projection 1062 of the second connector component 1060, or extend from the projection 106 and be located within the cavity 1064 of the first connector component 1058. In various embodiments, the first pipe fitting 1052 and the second pipe fitting 1063 are each configured to be attached to a portion of the shaft 104. The projection 1062 includes an inner surface 1070, which is configured to seal against the outer surface of the return pipe near the proximal end of the return pipe. The sealing area between the return pipe 326 and the inner surface 1070 of the projection 1062 is shown in Figure 12. In various embodiments, the shaft-handle connector 103 is constructed from any or more preferred materials, such as flexible metal, polymer, composite material, or equivalent. In one embodiment, the shaft-handle connector 103 is made of nitinol (NiTi), stainless steel, or the like.

[0106] [Catheter assembly (Figures 12-13)] Referring now to Figures 12 and 13, various diagrams of the catheter assembly are shown. Figure 12 is a schematic diagram of a catheter assembly according to various embodiments of this specification. Figure 13 is a cross-sectional view of a catheter assembly according to various embodiments of this specification. In various embodiments, the catheter assembly 1264 may include the shaft 104 and shaft-handle connector 103 of the cryoablation system 100. In some embodiments, the catheter assembly 1264 includes components of the cryoablation system that are replaced each time a cryoablation procedure is performed.

[0107] In various embodiments, the shaft 104 may include a supply pipe 324 extending along a portion of the shaft's length. The supply pipe may be surrounded by a return pipe 326 along a portion of its length. The return pipe 326 may be surrounded by an insulated shaft 328 along an insulated region 105 of the shaft. In the example shown in Figures 12-13, the supply pipe 324 extends and terminates furthest in the proximal direction 639 of the cryoablation system 100, and the insulated shaft 328 extends and terminates furthest in the distal direction 637 of the cryoablation system. In alternative configurations, the various layers of the shaft 104 may terminate along the same location in the cryoablation system 100.

[0108] In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the insulated shaft 328. In the example shown in Figures 12-13, the first pipe fitting 1052 of the shaft-handle connector 103 is configured to seal around the proximal end of the insulated shaft 328. In some embodiments, the insulated shaft 328 can be permanently connected to the shaft-handle connector 103. For example, the proximal portion of the insulated shaft 328 may be fitted inside the shaft-handle connector 103, and a portion 1366 of the first pipe fitting 1052 can be melted and reflowed (or joined by another preferred means) across the outer surface of the insulated shaft 328 to form a seal between the insulated shaft 328 and the shaft-handle connector 103. In alternative embodiments, the insulated shaft 328 may be removably connected to the shaft-handle connector 103 using any preferred fastening means.

[0109] In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the return pipe 326. As shown in the example in Figure 13, the inner surface 1070 of the second pipe fitting 1063 and / or projection 1062 of the shaft-handle connector 103 is configured to seal around the proximal end of the return pipe 326. In some embodiments, the return pipe 326 may be permanently connected to the shaft-handle connector 103. For example, the proximal portion of the return pipe 326 may be fitted inside the shaft-handle connector 103, and a portion 1368 of the second pipe fitting 1063 may be melted and reflowed (or joined by another preferred means) across the outer surface of the return pipe 326 to form a seal between the return pipe 326 and the shaft-handle connector 103. In alternative embodiments, the return pipe 326 may be removably connected to the shaft-handle connector 103 using any preferred fastening means.

[0110] In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the supply pipe 324. In the example shown in Figures 12-13, 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 pipe 324. The fluid conduit 868 may include an internal space 1067 surrounded by an inner surface 1069, which is configured to seal against the outer surface of the supply pipe 324. In some embodiments, the supply pipe 324 may be permanently connected to the shaft-handle connector 103. For example, the proximal portion of the supply pipe 324 may be fitted inside the shaft-handle connector and permanently joined to the fluid conduit 868 of the shaft-handle connector 103 (e.g., by soldering, brazing, etc.). In alternative embodiments, the supply pipe 324 may be detachably connected to the shaft-handle connector 103 using any preferred fastening means.

[0111] [How to operate the cryoablation system (Figure 14)] Many different methods are contemplated herein, including but not limited to manufacturing methods and usage methods. The modes of system / device operation described elsewhere in this specification may be performed as operations of one or more methods according to various embodiments herein.

[0112] Referring here to Figure 14, a method 1400 for operating a cryoablation system is described. Method 1400 may include a step 1402 for preparing 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 the working gas circuit and the precooler gas circuit. The cryoablation system may further include a first catheter assembly. The first catheter assembly may include a first shaft and a first shaft-handle connector. The first shaft may include a first working gas expansion chamber. The cryoablation system may further include a handle having a handle portion of the precooler gas circuit and a handle portion of the working gas circuit isolated from the handle portion of the precooler gas circuit. In various embodiments, the proximal end of the first shaft is configured to connect to the first shaft-handle connector.

[0113] Method 1400 may include step 1404 of removing the first catheter assembly from the handle. In various embodiments, the 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 is removably attached to the handle by the first shaft-handle connector, allowing the first shaft to be removed from the handle without damaging the handle. Furthermore, the first catheter 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 catheter assembly is attached to the handle.

[0114] In the examples shown in Figures 6 to 8, 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 (for example, by rotating the fastener away from the handle) and removing the shaft from the handle. In various embodiments, the step 1404 of removing the catheter assembly 1264 from the handle 102 may be performed each time the cryoablation system is used, for example, when a cryoablation procedure is performed on a patient.

[0115] Method 1400 may include step 1406 of attaching a second catheter assembly to the handle. In various embodiments, the second catheter assembly comprises a second shaft and a second shaft-to-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-to-handle to form a second catheter assembly and detachably attaching the second catheter assembly to the handle. The second catheter assembly can be assembled and attached to the handle using any preferred procedure of the steps, but one exemplary procedure is described in detail below.

[0116] In the example shown in Figures 12-13, the shaft-handle connector 103 may include a first connector component 1058 and a second connector component 1060. The projection 1062 of the second connector component 1060 is configured to extend into a cavity 1064 formed within the first connector component 1058. In such an embodiment, the insulated shaft 328 can first be joined to the first connector component 1058 in order to attach the shaft 104 to the shaft-handle connector 103. For example, the proximal portion of the insulated shaft 328 may be fitted inside the shaft-handle connector 103, and a portion 1366 of the first pipe fitting 1052 may be melted (or joined by another preferred means) across the outer surface of the insulated shaft 328 to form a seal between the insulated shaft 328 and the shaft-handle connector 103.

[0117] After the insulated shaft 328 is attached to the first connector component 1058, the return pipe 326 and the supply pipe 324 can be joined to the second connector component 1060, and the first connector component 1058 can be attached to the second connector component 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 pipe fitting 1063 can be melted (or joined by another preferred means) across 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 conduit 868 of the shaft-handle connector 103 is configured to seal around the proximal end of the supply pipe 324. The first connector component 1058 can then be securely attached to the second connector component 1060 by any preferred means, such as a crimp fit.

[0118] After assembling the second catheter assembly, it can be removably attached to the distal end of the handle and secured to the handle using fasteners or the like.

[0119] The concepts described herein may be applied to and used in connection with the cryoablation systems and components described in the following four U.S. Patent Applications filed on May 22, 2024: U.S. Patent Application No. 18 / 671,489, entitled "Cryoablation Catheter Shaft Construction"; U.S. Patent Application No. 18 / 671,727, entitled "Safety Devices for Cryoablation Probe"; U.S. Patent Application No. 18 / 671,677, entitled "Delivery Systems for Cryoablation Device"; and U.S. Patent Application No. 18 / 671,742, entitled "Distal Tip Structure for Cryoablation Probe," which are incorporated herein by reference in their entirety.

[0120] As used herein and in the claims, “a / an” and “the” include multiple subjects unless otherwise explicitly indicated. The term “or” is generally used to include “and / or” unless otherwise explicitly indicated.

[0121] As used herein and in the claims, the term “configured” describes a system, apparatus, or other structure that is built or configured to perform a particular process or employ a particular configuration. The term “configured” may also be used interchangeably with other similar terms such as arranged and configured, built and positioned, constructed, manufactured and positioned.

[0122] All publications and patent applications herein represent the level of skill of those skilled in the art to which the present invention pertains. All publications and patent applications are incorporated herein by reference to the same extent as if each individual publication or patent application were specifically and individually indicated by reference.

[0123] As used herein, an enumeration of numerical ranges by endpoints includes all numbers contained within that range (for example, 2 to 8 includes 2.1, 2.8, 5.3, 7, etc.). The headings used herein are for structural reference only. These headings should not be considered to limit or characterize any invention described in any claim that may arise from this disclosure. For example, with respect to the heading "Technical Field," the claims should not be limited by the language selected under that heading to describe that technical field. Similarly, the description of the technology in "Background Art" does not constitute prior art to any invention in this disclosure. Furthermore, the "Summary of the Invention" should not be considered as a characteristic of the invention described in the claims.

[0124] The embodiments described herein are not intended to be exhaustive, nor are they intended to limit the invention to the exact forms disclosed in the detailed description. Rather, the embodiments are selected and described so that those skilled in the art can recognize and understand the principles and practices. Several aspects have been described above with reference to various specific preferred embodiments and techniques. However, many changes and modifications can be made that fall within the spirit and scope of this disclosure.

Claims

1. A cryoablation system, The working gas circuit and A vacuum chamber isolated from the aforementioned operating gas circuit, A shaft, wherein the shaft extends along its length, An insulating region along the proximal length of the shaft, comprising a vacuum chamber shaft portion and an insulating portion of the working gas circuit, wherein the vacuum chamber shaft portion surrounds the insulating portion of the working gas circuit and is isolated from the insulating portion of the working gas circuit, A working gas expansion chamber located distal to the adiabatic region, the working gas expansion chamber including the expansion portion of the working gas circuit, and the shaft including the working gas expansion chamber, A shaft-handle connector, wherein the proximal end of the shaft is connected to the shaft-handle connector, and the shaft-handle connector is configured to detachably attach the proximal end of the shaft to the distal end of the handle, and the shaft-handle connector further comprises A working gas connector structure configured to form a sealed connection with the working gas supply passage and the working gas discharge passage within the handle, The shaft-handle connector includes a vacuum connector structure configured to form a sealed connection with the vacuum chamber portion of the handle, A cryoablation system comprising a shaft-handle connector including a connector portion of the vacuum chamber isolated from the connector portion of the operating gas circuit.

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

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

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

5. The cryoablation system according to any one of claims 1 to 4, 6 to 13, wherein the second connector 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 pipe.

6. The cryoablation system according to any one of claims 1 to 5, 7 to 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 to 6, 8 to 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 pipe.

8. The cryoablation system according to any one of claims 1 to 7, 9 to 13, wherein the shaft-handle connector includes a connector portion of the vacuum chamber, and the shaft-handle connector is configured to form one or more openings that communicate fluidly with the connector portion of the vacuum chamber and to be connected to the vacuum chamber portion of the handle.

9. The cryoablation system according to any one of claims 1 to 8, 10 to 13, wherein the shaft-handle connector forms one or more openings between the handle and the shaft-handle connector through which the return portion of the operating gas circuit passes.

10. The cryoablation system according to any one of claims 1 to 9, 11 to 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, and the working gas circuit includes a working gas Joule Thomson orifice at a position where the working gas enters the working gas expansion chamber.

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

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

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

14. A method for operating a cryoablation system, A step of preparing a cryoablation system, wherein the cryoablation system is The working gas circuit and A first catheter assembly comprising a first shaft and a first shaft-handle connector, wherein the first shaft comprises a first working gas expansion chamber and the first catheter assembly, The operating gas circuit includes a handle, The proximal end of the first shaft is connected to the first shaft-handle connector, and the first shaft-handle connector is detachably attached to the distal end of the handle, the steps of preparing the cryoablation system, The steps include removing the first catheter assembly from the handle, A method comprising the step of attaching a second catheter assembly to the handle, wherein the second catheter assembly includes a second shaft and a second shaft-handle connector, the second shaft includes a second working gas expansion chamber, the proximal end of the second shaft is connected to the second shaft-handle connector, and 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, and the working gas circuit includes a working gas Joule-Thomson orifice at a position where the working gas enters the working gas expansion chamber.

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