CN121908996A

CN121908996A - Multi-gas circuit connector and method for cryoablation system

Info

Publication number: CN121908996A
Application number: CN202480057395.0A
Authority: CN
Inventors: 凯尔·特鲁; 埃里克·T·冈纳; 蒂莫西·A·奥斯特罗特; 科里·罗斯·斯滕伯格; 本杰明·伟-文·陈; 扎卡里·尼克尔
Original assignee: Scimed Life Systems Inc
Current assignee: Boston Scientific Scimed Inc
Priority date: 2023-09-08
Filing date: 2024-05-23
Publication date: 2026-04-21
Also published as: WO2025053882A1

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. The cryoablation system may include a shaft having an isolation region and a working gas expansion chamber distal to the isolation region. The cryoablation system may further include a handle and a shaft-handle connector, wherein the 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 the distal end of the handle.

Description

Multi-gas circuit connector and method for cryoablation system

Cross Reference to Related Applications

The present application is a PCT international patent application filed 5/23/2024, which is the applicant designated by the name of Boston SCIENTIFIC SCIMED, national company, us, and the inventors designated by all countries, us citizen Kyle True, us citizen Eric t. Gamner, us citiothy a Ostroot, us citizen Cory Ross Stenberg, and us citizen Benjamin Wai-Man Chan and us citizen Zachary Nickle. The present application claims priority from U.S. provisional application Ser. No.63/537,324, filed on 8 at 9 at 2023, and U.S. application Ser. No.18/671,677, filed on 22 at 5 at 2024, the contents of which are incorporated herein by reference in their entireties.

Technical Field

Embodiments herein relate to cryoablation systems, and more particularly, to a cryoablation system having a detachable shaft.

Background

During cryosurgery, a surgeon may employ one or more cryoprobes to ablate a target region of a patient's anatomy by freezing and thawing tissue. In one example, the cryoprobe uses the Joule-Thomson effect to create cooling or heating of the probe tip. In this case, expansion of the cryofluid in the cryoablation probe from a higher pressure to a lower pressure cools the device tip to a temperature at or below a temperature corresponding to cryoablation in tissue near the tip. The heat transfer between the expanding chilled fluid and the outer wall of the cryoprobe causes formation of a balloon in the tissue surrounding the tip, thereby cryoablating the tissue.

Disclosure of Invention

In a first aspect, a 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 a proximal length of the shaft. The isolation region may include a vacuum chamber shaft portion and an isolation portion of the working gas circuit, wherein the vacuum chamber shaft portion surrounds and may be isolated from the isolation portion of the working gas circuit. The shaft may include a working gas expansion chamber 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 a vacuum chamber and a handle portion of a working gas circuit. The cryoablation system may also include a shaft-handle connector. The proximal end of the shaft may be connected to a 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.

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

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

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

In a fifth aspect, in addition to or as an alternative to one or more of the foregoing or following aspects, the second connection piece of the shaft-handle connector includes an interior space, and an interior surface of the interior space may be configured to form a seal around an exterior surface of the supply tube.

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

In a seventh aspect, in addition to or as an alternative to one or more of the foregoing or following aspects, the shaft may be removed from the handle without any impairment of the ability of the handle to isolate the handle portion of the working gas circuit from the handle portion of the vacuum chamber.

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

In a ninth aspect, in addition to or as an alternative to one or more of the foregoing or following 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.

In a tenth aspect, in addition to or as an alternative to one or more of the foregoing or following aspects, the cryoablation system further comprises a precooler gas circuit isolated from the working gas circuit and the vacuum circuit, wherein the handle comprises a handle portion of the precooler gas circuit. The precooler gas circuit may be configured to supply precooler gas from a high-pressure, low-temperature gas source to the handle, and the precooler gas circuit may include a precooler joule-thomson orifice at which precooler gas enters the precooler expansion chamber.

In an eleventh aspect, in addition to or as an alternative to one or more of the foregoing or following aspects, the working gas circuit may be configured to supply working gas from a high pressure, low temperature gas source to the 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.

In a twelfth aspect, a 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 a proximal length of the shaft, 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 may be isolated from the isolation portion of the working gas circuit. The shaft may include a working gas expansion chamber 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. The proximal end of the shaft may be connected to a 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. The shaft-handle connector also includes a working gas connector structure configured to form a sealed connection with the working gas supply passage in the handle and the working gas exhaust passage in the handle, and 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.

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

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

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

In a sixteenth aspect, in addition to or as an alternative to one or more of the foregoing or following aspects, the second piece of the shaft-handle connector includes an interior space, and an interior surface of the interior space may be configured to form a seal around an exterior surface of the supply tube.

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

In an eighteenth aspect, in addition to or as an alternative to one or more of the foregoing or following 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.

In a nineteenth aspect, in addition to or instead of one or more of the preceding or following aspects, the working gas circuit may be configured to supply working gas from a high pressure, low temperature 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.

In a twentieth aspect, a method of operating a cryoablation system may include providing a 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 a working gas circuit. The proximal end of the first shaft may be connected to a first shaft-handle connector, and the first shaft-handle connector removably attaches the proximal end of the first shaft to the distal end of the handle. The method may include removing the 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 may include a second working gas inflation 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 the distal end of the handle.

This summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive explanation of the present subject matter. Further details can be found in the detailed description and the appended claims. Other aspects will be apparent to those skilled in the art upon reading and understanding the following detailed description and viewing the accompanying drawings that form a part thereof, none of which should be considered limiting. The scope of protection herein is defined by the claims that follow and their legal equivalents.

Drawings

The aspects may be more completely understood in consideration of the following drawings (figures), in which:

Fig. 1 is a schematic diagram of a cryoablation system in accordance with various embodiments herein.

Fig. 2 is a schematic diagram of a portion of a cryoablation system in accordance with various embodiments herein.

Fig. 3 is a schematic view of a portion of a cryoablation shaft shown in accordance with various embodiments herein.

FIG. 4 is a cross-sectional view of the shaft of FIG. 3 taken along section 4-4 in FIG. 3, in accordance with various embodiments herein.

FIG. 5 is a cross-sectional view of the shaft of FIG. 3 taken along section 5-5 in FIG. 3, in accordance with various embodiments herein.

Fig. 6 is a schematic diagram of a cryoablation system in accordance with various embodiments herein.

Fig. 7 is a cross-sectional view of the cryoablation system of fig. 6 along line 7-7 in fig. 6 in accordance with various embodiments herein.

Fig. 8 is a close-up view of the cryoablation system of fig. 7 with respect to detail 8 in fig. 7 in accordance with various embodiments herein.

Fig. 9 is a side view of a shaft-handle connector according to various embodiments herein.

Fig. 10 is a cross-sectional view of a shaft-handle connector according to various embodiments herein.

Fig. 11 is an exploded side view of a shaft-handle connector according to various embodiments herein.

Fig. 12 is a side view of a catheter assembly according to various embodiments herein.

Fig. 13 is a cross-sectional view of a catheter assembly according to various embodiments herein.

Fig. 14 is a flow chart describing a method for using a cryoablation system in accordance with various embodiments herein.

While the embodiments are susceptible to various modifications and alternative forms, details thereof have been shown by way of example and the accompanying drawings and will be described in detail. However, it should be understood that the scope of the present disclosure is not limited to the particular aspects described. On the contrary, the invention is to cover modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

Detailed Description

Cryoablation (also known as cryotherapy or cryosurgery) is a medical procedure involving the use of 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 (heart treatment), dermatology (skin treatment), and the like. In cryoablation, a shaft is inserted into or near the target tissue. The shaft contains cryogenic substances, such as liquid nitrogen or argon, for rapid cooling of the tissue to very low temperatures. Extreme cold causes ice crystals to form within the cell, leading to cell damage and ultimately cell death.

In some applications, cryoablation systems use a rigid shaft to deliver cryogenic substances to a target anatomy. Rigid shafts are generally stronger but provide limited access to the anatomy of the patient. Some cryoablation systems may be used to ablate lesions of the biliary system or other inaccessible parts of the human anatomy. To approximate such anatomical features, a flexible cryoablation shaft may be implemented. However, flexible shafts are more challenging to contain high pressure gases.

In most cases, the catheter of the cryoablation system is considered a single use item and is designed to be removed and replaced after the cryoablation procedure is performed. Where possible, it may be desirable to reuse other portions of the cryoablation system, such as the handle and console, in multiple cryoablation procedures.

The present disclosure relates to a cryoablation system having a detachable catheter assembly. The catheter assembly may include a shaft and a shaft-handle connector. The shaft may be removably attached to the handle using a shaft-handle connector. The shaft-handle connector allows for replacement of the shaft of the cryoablation system while maintaining multiple fluid circuits (e.g., precooler gas, working gas, and vacuum) within the handle isolated from each other.

The concepts described herein may be applied in the context of a cryoablation system as described in U.S. published patent application US2021/00045793 entitled "Dual Stage Cryocooler (dual stage cryocooler)" and U.S. published patent application US2021/00045794 entitled "Flexible Cryoprobe (flexible cryoprobe"), both filed on even 14, 8, 2020, which are incorporated herein by reference in their entirety.

Referring now to fig. 1, a schematic diagram of a cryoablation system is shown, in accordance with various embodiments herein. In various embodiments, the cryoablation system may include a handle 102 and a shaft 104. In various embodiments, the shaft 104 may be inserted into the handle 102 and may be securely attached to the handle by a shaft-handle connector 103. In various embodiments, the shaft 104 and the shaft-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 connectable to the cryoablation system 100.

These three sources correspond to three separate circuits in cryoablation system 100, a precooler, working fluid, and 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 circuit remains isolated from the other.

In some embodiments, the cryoablation system 100 includes a console 117. The console may be used in a control system and may be in electrical and fluid communication with the handle and the cryoablation assembly. In some embodiments, the working fluid source 110, the precooler fluid source 112, and the vacuum source 114 may all be connected to a console 117 of the cryoablation system 100 using tubing. In some embodiments, precooler gas vent 116, working gas vent 118, or both may be connected to a conduit that carries the emissions back to console 117 or other location within the operating room where the emissions are vented to the ambient environment at the appropriate location. It should be noted that the various sources and drains may be placed in any suitable configuration along handle 102, and that the arrangement of fig. 1 is merely one example of a suitable configuration.

The following paragraphs provide examples of the specifications and functions of each of these circuit species. However, it should be noted that the particular fluid and pressure values are for exemplary purposes, and that other configurations are possible.

In one embodiment, the precooler circuit may contain pressurized argon gas at 24.1 megapascals (MPa). The precooler circuit may cool an incoming working fluid stream and may operate in a handle. In one embodiment, the working fluid circuit may contain 12.4 Mpa pressurized argon and/or 12.4 MPa pressurized helium. The working fluid circuit generates and/or melts ice balls. The working fluid circuit may operate in the handle, isolated portion or region of the shaft, and the expansion chamber of the shaft. In one embodiment, the active vacuum may maintain a vacuum level of less than or equal to 6.67 pascals (Pa). The active vacuum may isolate the shaft. The active vacuum may operate in an isolated region of the handle and shaft.

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

During ablation (freeze cycle), 12.4MPa of argon gas is circulated through the probe to create an ice ball around the expansion chamber 106 within the patient. The working fluid may be any suitable cooling fluid (e.g., nitrogen, air, argon, krypton, xenon, N ₂O、CO₂、CF₄). In some embodiments, the pressure of the high pressure stream of the working fluid may be greater than or equal to 6.9MPa, 8.3MPa, 9.7MPa, 11.0MPa, 12.4MPa, 17.2MPa, 27.6MPa, or 41.4MPa. In some embodiments, the pressure of the high pressure stream of the working fluid may be less than or equal to 55.2MPa, 34.5MPa, 20.7MPa, 18.6MPa, 16.5MPa, 14.5MPa, or 12.4MPa. In some embodiments, the pressure of the high pressure stream of the working fluid may fall within a range of 6.9MPa to 41.4MPa, or 8.3MPa to 27.6MPa, or 9.7MPa to 16.5MPa, or 11.0MPa to 14.5MPa, or may be about 12.4MPa. Thus, in embodiments where the working fluid is a cooling fluid, the temperature of the working fluid at the expansion chamber 106 may be about 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 a range between any of the foregoing values.

In various embodiments, the precooler circuit is entirely contained within the handle 102. In various embodiments, the precooler circuit is located in a console 117 of the system. In various embodiments, the precooler circuit is located in a portion of the conduit immediately proximal to the handle. In various embodiments, the precooler circuit is located in a portion of the catheter immediately distal to the handle. In various embodiments, the precooler circuit operates 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 10.3MPa, 13.8MPa, 17.2MPa, 20.7MPa, or 24.1MPa. In some embodiments, the pressure of the precooler fluid may be less than or equal to 31.0MPa, 29.3MPa, 25.9MPa, or 24.1MPa. In some embodiments, the pressure of the precooler fluid may fall within the range of 10.3MPa to 31.0MPa, or 13.8MPa to 29.3MPa, or 17.2MPa to 27.6MPa, or 20.7MPa to 25.9Mpa, or may be about 24.1MPa.

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

The shaft 104 may be any suitable length capable of reaching a target anatomy within the subject. In some embodiments, the shaft length may be greater than or equal to 20cm, 38cm, 55cm, 72cm, or 90cm. In some embodiments, the shaft length may be less than or equal to 150cm, 135cm, 120cm, 105cm, or 90cm. In some embodiments, the shaft length may be in the range of 20cm to 150cm, or 38cm to 135cm, or 55cm to 120cm, or 72cm to 105cm, or may be about 90cm.

In various embodiments, certain 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 may have sufficient flexibility to form a curve having a desired radius of curvature. For example, the shaft may have sufficient flexibility such that the shaft may form a curve having a minimum radius of curvature of less than or equal to 30mm, 20mm, 10mm, or 5 mm.

In various embodiments, the shaft 104 may include an isolation region 105 and an expansion chamber 106. Isolation region 105 defines the portion of shaft 104 that is isolated by the vacuum chamber. The expansion chamber 106 defines an uninsulated portion of the shaft 104 and creates an ice ball at that portion. In various embodiments, the flexible shaft carries the high pressure working fluid from the handle 102 to an expansion chamber 106 where the high pressure working fluid undergoes joule-thompson expansion and a corresponding temperature change. The working fluid flows down the flexible shaft, through the handle, or into and out of the handle before being vented from the console to atmosphere.

The distal end of the shaft may terminate in a distal operating tip 108. During use, the distal operating tip 108 is deployed within the patient, surrounded by tissue, and in some cases cryoablates tissue. In some cases, the distal operating tip 108 may be advantageously configured to pierce tissue. For example, the distal operating tip 108 may include a sharp tip, such as a trocar tip. Alternatively, the distal operating tip 108 may not be a sharp tip. In some embodiments, the distal operating tip 108 may be an atraumatic tip designed to cause minimal tissue damage. In some embodiments, the distal operating tip 108 may also contain a working port configured for any of aspiration, delivery of therapeutic agents, and delivery of other devices including, but not limited to, guidewires, imaging catheters, sensing devices, biopsy devices, balloons, and stents.

Handle with precooler circuit (figure 2)

Referring now to fig. 2, a schematic diagram of portions of a cryoablation system in accordance with various embodiments herein is shown. In some aspects, cryoablation system 100 may include a working fluid source 110 connected to the working fluid circuit and a precooler fluid source 112 connected to the precooler fluid circuit. The working fluid circuit may include a working fluid supply line 210 for carrying a high pressure flow of working fluid from the working fluid source 110 to a distal end (not shown in this view) of the shaft 104. The working fluid circuit may also include a working fluid return line (not shown in this view) for carrying the low pressure flow of working fluid from the distal end of the shaft back to the base of the handle 102.

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 precooler fluid source 112 to a precooler fluid expansion zone 222 in handle 102. The precooler fluid circuit may also include a precooler return line (indicated by arrow 213). The precooler return line may be configured to carry precooler fluid from the precooler fluid expansion region 222 back to the base of the handle 102. A precooler return line may be housed along with precooler supply circuit 212 and extend back to the console and gas manifold.

In various embodiments, the precooler fluid circuit may facilitate heat exchange between the working fluid and the precooler fluid. For example, in embodiments where the working fluid cools upon expansion to cryoablate tissue surrounding the distal working tip 108, a precooler fluid circuit may 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. The first heat exchanger 216 may facilitate heat exchange between a high pressure flow of the working fluid in the working fluid supply line 210 and a low pressure flow of the precooler fluid in the precooler return line.

In various embodiments, precooler supply line 212 may include a second heat exchanger 218 that allows heat exchange (e.g., recuperative heat exchange) between the high-pressure flow of the precooler fluid and the low-pressure flow of the precooler fluid. In various aspects of the embodiments, the precooler fluid may also be a cooling fluid. In such embodiments, the recuperative heat exchange between the high pressure flow of the precooler fluid and the low pressure flow of the precooler fluid may remove heat from the high pressure flow of the precooler fluid. Thus, the second heat exchanger 218 may facilitate pre-cooling the high pressure flow of the precooler fluid.

In various embodiments, the high pressure flow of the precooler fluid exiting the second heat exchanger 218 continues to flow through the precooler supply line 212 to the precooler fluid expansion zone 222. In the precooler fluid expansion zone fully contained in the handle 102, the precooler supply line 212 terminates in a joule-thomson orifice. The high pressure flow of the precooler fluid may be expanded at or downstream of the joule-thomson orifice in the precooler fluid expansion zone 222. The rapid drop in pressure causes a corresponding drop in temperature. The precooler fluid expansion zone 222 may be in fluid communication with a precooler return line to carry an expanded low pressure flow of precooler fluid (e.g., vented to atmosphere if the precooler fluid circuit is an open circuit or returned to the precooler fluid source if the precooler fluid circuit is a closed circuit). After expansion at 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 line, it cools the working fluid at the first heat exchanger 216.

The working fluid circuit 210 may also include a third heat exchanger 220 in the shaft 104 of the cryoablation system configured for 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 returned through the shaft 104 (not shown in this view).

Distal tip and inflation chamber details (fig. 3)

Referring now to fig. 3, a schematic diagram of a portion of a cryoablation shaft is shown, in accordance with 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 the shaft 104 includes a supply line 324 within a return line 326 that is located within an isolation shaft 328. The concentric shaft structure is designed to isolate the working fluid circuit 210 and the vacuum chamber 336 from each other.

In various embodiments, after exiting the handle 102, the high pressure flow of working fluid travels down the supply tube 324. When the working fluid reaches the working fluid expansion chamber 106, the supply tube 324 terminates in a joule-thomson orifice 332 or distal outlet 332. The high pressure flow of working fluid may be expanded at or downstream of the joule-thomson orifice 332 in the expansion chamber 106. The rapid drop in pressure causes a corresponding drop in temperature. The heat transfer between the expanding working fluid and the outer wall of the expansion chamber 106 causes formation of an ice ball in the tissue surrounding the tip 108, thereby causing cryoablation of the tissue.

The 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 324 and return 326 lines of the expansion chamber) to carry an expanded low pressure flow of working fluid (e.g., vented to atmosphere if the working fluid circuit is an open circuit, or returned to the working fluid source if the working fluid circuit is a closed circuit). As the working fluid passes through the working fluid return line, it cools the working fluid input stream at the third heat exchanger 220 (fig. 2).

In various embodiments, the working fluid is a cooling fluid and a cooling gas (e.g., nitrogen, air, argon, krypton, xenon, N2O, CO, CF 4). In this case, the high pressure flow of working fluid may be at a pressure such that expansion via the Joule-Thomson orifice 332 may cause the working fluid to cool to a temperature for cryoablating tissue surrounding the expansion chamber 106. In certain aspects, the pressure of the high pressure flow of the working fluid upstream of the Joule-Thomson orifice 332 may be about 6.9MPa and about 13.8MPa (e.g., about 12.4 MPa). Thus, in embodiments where the working fluid is a cooling fluid, the temperature of the working fluid after expansion from the Joule-Thomson orifice 332 may be greater than or equal to 150, 160, 170, 180, 190, or 200 Kelvin, or may be an amount falling within any of the foregoing ranges.

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

Referring to fig. 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 draw a vacuum along the length of the isolation region 105 of the shaft 104. In one embodiment, a vacuum is drawn between the outer diameter of return tube 326 and the inner diameter of isolation shaft 328 throughout isolation region 105 of shaft 104.

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 the cryogenic exhaust. 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 tube 324 and the return tube 326. In other embodiments, the vacuum source 114 is directly connected to the shaft 104, for example, using a T-fitting along the length of the shaft 104.

To provide thermal insulation along the insulation region 105 of the shaft 104, the wall of the flexible shaft is a double wall (return tube surrounded by the insulation shaft) with a small gap between the return tube 326 and the insulation shaft 328. By drawing a vacuum between the return tube and the isolation shaft, convective heat transfer is prevented such that the temperature of the working fluid does not ablate or cause uncontrolled apoptosis/necrosis of healthy non-target patient tissue along the isolation region of the shaft. By actively drawing air out of the gap and maintaining a vacuum of about 0.05 torr, a sufficient thermal insulation effect is achieved. However, other vacuum pressures may be suitable depending on the configuration of the cryoablation system. In some embodiments, support filaments 330 wrap around the outer diameter of return tube 326. One option for the filament material is a polymer such as Polyetheretherketone (PEEK). The filaments prevent direct contact between the outer surface of the return tube and the inner surface of the isolation shaft. Filament 330 minimizes heat conduction between the inner shaft and the insulation shaft. Other alternatives may be used in place of filament 330, such as an extruded tube/co-extruded shape or other features placed on the shaft.

In some embodiments, the shaft may not include filaments. In such embodiments, the return tube 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.

There is a joint 334 at the junction of the isolation zone 105 and the expansion chamber 106. Such a joint is capable of sealing the vacuum layer.

Flexible shaft cross section, dimensions and materials (FIG. 4)

Referring now to fig. 4, a cross-sectional view of the shaft of fig. 3, taken along section 4-4, is shown in accordance with various embodiments herein. In various embodiments, the isolation region 105 of the shaft 104 includes a supply tube 324 positioned concentrically within a return tube 326 positioned concentrically within an isolation shaft 328. The isolation region 105 may include an axial portion of the vacuum chamber 336 and an isolated portion of the working gas circuit 210. In various embodiments, the vacuum chamber 336 surrounds and is isolated from the isolated portion of the working gas circuit 210.

In various embodiments, after exiting the handle 102, the high pressure flow of working fluid travels distally, downwardly through the supply tube 324 to the isolated region of the shaft. After cooling and expansion in the expansion chamber 106, the working fluid travels proximally back through the isolation region 105 of the shaft 104 in the annular space between the supply tube 324 and the return tube 326.

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

In various embodiments, the supply tube 324 (also referred to herein as a capillary tube) is constructed of any suitable material or materials, such as flexible metals, polymers, composites, and the like. In one embodiment, the supply tube 324 is constructed of nitinol (NiTi), stainless steel, or the like.

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

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

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

In various embodiments, return tube 326 is constructed of any suitable material or materials, such as flexible metals, polymers, and the like. In various embodiments, return tube 326 may be made of polyimide, fluorinated Ethylene Propylene (FEP), teflon, or the like. In one embodiment, return tube 326 is formed of a polyimide material because it is highly impermeable to gases over a wide range of temperatures, and thus can internally contain a working fluid and externally maintain a vacuum. In a particular example, the return tube 326 is made of a braided reinforced polyimide tube to enhance gas impermeability, burst strength, and flexibility. In some embodiments, return tube 326 is formed from a single layer of material. In some embodiments, the return tube 326 may be formed of two or more layers of material selected to optimize the performance of the shaft 104. The layers of material may be bonded together using any suitable technique, such as adhesives, hot melt reflow processes, and the like.

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

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

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

In various embodiments, isolation shaft 328 is constructed of any suitable material or materials, such as flexible metals, polymers, and the like. In various embodiments, isolation shaft 328 is made of polyimide, fluorinated Ethylene Propylene (FEP), teflon, or the like. In particular embodiments, the isolation shaft 328 may include Polytetrafluoroethylene (PTFE), and/or one or more polyether block amides (trade name Pebax, hereinafter "Pebax").

In some embodiments, the isolation shaft 328 is formed from a single layer of material. In some embodiments, the isolation shaft 328 may be formed from two or more layers of materials that are selected to optimize the performance of the shaft 104. The layers of material may be bonded together using any suitable technique, such as adhesives, hot melt reflow processes, and the like.

In one embodiment, the insulation shaft may be formed using a woven reinforced polyimide tube with a Pebax outer layer coated on the surface. This three-layer construction is capable of maintaining a high vacuum between the return tube and the isolation shaft without causing the isolation shaft 328 to collapse onto the return tube 326.

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

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

In some embodiments, the thickness of the isolation shaft 328 may be greater than or equal to 0.10mm, 0.11mm, 0.12mm, 0.14mm, or 0.15mm. In some embodiments, the thickness of the isolation shaft 328 may be less than or equal to 0.20mm, 0.19mm, 0.18mm, 0.16mm, or 0.15mm. In some embodiments, the thickness of the isolation shaft 328 may fall within a range of 0.10mm to 0.20mm, or 0.11mm to 0.19mm, or 0.12mm to 0.18mm, or 0.14mm to 0.16mm, or may be about 0.15mm.

In some embodiments, PEEK filament 330 is wrapped around return tube 326. The pitch of PEEK filaments 330 may be greater than or equal to 0.5mm, 1.0mm, 1.5mm, or 2.0 mm, or may be an amount falling within a range between any of the foregoing values. Alternatively, the filaments may be a plurality of discrete pieces attached along the return tube 326. The PEEK filament 330 prevents 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 over the filaments at the ends of return tube 326 and isolation shaft 328 to attach PEEK filaments 330. In various embodiments, the PEEK filament windings are configured to minimize or prevent convective heat transfer from the return tube to the isolation shaft. In alternative embodiments, other insulating polymers may be used as alternatives to PEEK filaments, such as expanded polytetrafluoroethylene (ePTFE), nylon, and the like.

In some embodiments, the PEEK filaments 330 may have a diameter of greater than or equal to 0.002mm, 0.004mm, or 0.005mm. In some embodiments, the PEEK filaments 330 may have a diameter of less than or equal to 0.007mm, 0.006mm, or 0.005mm. In some embodiments, the diameter of PEEK filaments 330 may fall within the range of 0.002mm to 0.007mm, or 0.004mm to 0.006mm, or may be about 0.005mm.

Shaft in expansion chamber (FIG. 5)

Referring now to fig. 5, a cross-sectional view of the shaft of fig. 3, taken along section 5-5, is shown in accordance with various embodiments herein. The cross-sectional view of fig. 5 depicts the expansion chamber 106 of the shaft 104. In various embodiments, expansion chamber 106 is located distal to isolation region 105 along shaft 104. Expansion chamber 106 may include an expansion portion of working fluid circuit 210.

In various embodiments, after exiting the handle 102, the high pressure flow of working fluid travels down the supply tube 324. The working fluid, after cooling and expansion in the expansion chamber 106, travels back down 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 process gas and the patient tissue by optimizing parameters such as wall thickness, material, and the like.

In various embodiments, the expansion chamber 106 is constructed of any suitable material or materials, such as flexible metals, polymers, and the like. In various embodiments, the expansion chamber 106 is made of polyimide, fluorinated Ethylene Propylene (FEP), teflon, or the like. In some embodiments, the expansion chamber 106 includes a continuation of the return conduit 326 of the isolation region 105 of the shaft 104. Alternatively, the expansion chamber is a separate component from the return conduit 326, which may be coupled to the shaft 104 using any suitable joint and/or fitting, such as a hot melt return process, an adhesive bond, a braze bond, or any other suitable mechanical coupling process capable of withstanding cryogenic pressures and temperatures.

In some embodiments, the expansion chamber 106 is formed from a single layer of material. In some embodiments, the expansion chamber 106 is formed from two or more layers of material. The layers of material may be bonded together using any suitable technique, such as adhesives, hot melt reflow processes, and the like.

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

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

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

Cryoablation system (FIGS. 6-8)

Referring now to fig. 6-8, various views of a cryoablation system are shown herein. Fig. 6 is a schematic side view of a cryoablation system in accordance with various embodiments herein. Fig. 7 is a cross-sectional view of the cryoablation system of fig. 6 looking at the plane of the page along line 7-7 of fig. 6 in accordance with various embodiments herein. Fig. 8 is a close-up view of the cryoablation system of fig. 7 in relation to detail 8 of fig. 7 in accordance with various embodiments herein. Referring to the drawings, arrows have been added to indicate the distal direction 637 and the proximal direction 639.

In various embodiments, the cryoablation system 100 can 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 separate circuits in the cryoablation system 100, the precooler gas supply circuit 212, the working gas circuit 210, and the vacuum chamber 336. In the embodiment of fig. 6-8, 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 may be connected along any suitable portion of the handle 102.

Additionally or alternatively, the cryoablation system may include two, three, four, or more precooler gas sources. Alternatively, cryoablation system 100 does 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 stepped down 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 about 4000 psi to about 2000 psi in the first stage and from about 2000 psi to about 500 psi in the second stage.

In various embodiments, the precooler gas supply circuit 212 passes through the handle 102 and resides within the handle. The term "handle portion of the precooler gas supply circuit" will be used when referring to the portion of precooler gas supply circuit 212 that passes through handle 102. 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.

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, low-temperature gas source (in this case precooler gas source 112) to the handle 102. As shown and described in fig. 2, the precooler gas circuit may include a precooler joule-thomson orifice located in the precooler gas expansion zone 222.

The shaft 104 may include an isolation region 105 along a proximal length of the shaft. The isolation region 105 may include an axial portion of the vacuum chamber 336 and an isolated portion of the working gas circuit 210. As best shown in fig. 4, the vacuum chamber 336 surrounds and is isolated from the isolated portion of the working gas circuit 210. The shaft may include a working gas expansion chamber 106 located distally of the isolation region 105. As best shown in fig. 5, the working gas expansion chamber 106 includes an expansion portion of the working gas circuit 210.

As shown and described in fig. 2-3, the working gas circuit 210 is configured to supply working gas from a high pressure, low temperature gas source (in this case, the working gas source 110) to the working gas expansion chamber 106, the working gas circuit including a working gas joule-thomson orifice 332 at the working gas expansion chamber 106.

In various embodiments, the shaft 104 may be inserted into the handle 102 and may 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, and the shaft-handle connector is configured to removably attach the proximal end of the shaft 104 to the distal end of the handle 102. In the context of the present application, when the two components are removably attached, a first component (e.g., a handle of a cryoablation system) may be attached to and/or detached from a second component (e.g., a shaft of a cryoablation system) without damaging the first component. In some examples, the first component may be attached to and/or detached from the second component without damaging the first component or the second component. In other examples, the second component may be attached to and/or detached from the first component while intentionally plastically deforming a particular component of the second component without damaging the first component.

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, working gas circuit 210, and vacuum chamber 336 to remain isolated from one another within the handle 102 when the shaft 104 is removed from the handle. This configuration may increase the efficiency of the cryoablation system 100 because in many applications the shaft 104 is replaced each time a cryoablation procedure is performed, but the handle 102 may be reused. The shaft-handle connector 103 enables a 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).

In the example of fig. 6-8, the shaft 104 is permanently attached to the shaft-handle connector 103, and the shaft-handle connector 103 is removably attached to the handle 102 by a securing means (e.g., fastener 638). The shaft 104 may be removed from the handle 102 by releasing the securing means and removing the shaft-handle connector 103 from the handle 102. Additionally or alternatively, the shaft-handle connector 103 may be removably connected to the shaft 104 such that the shaft may be removed from the handle 102 without removing the shaft-handle connector 103.

In an alternative embodiment, the reusable handle 102 is configured to loss grip (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 tethered to the shaft 104 such that the shaft is snappable by the handle (e.g., portions of the shaft are plastically deformed and the shaft is a disposable wearing piece), 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 ferrules or sleeves located at the front and rear of the body and nut to form an airtight seal.

In the embodiment of fig. 6-8, the handle inner surface 844 is configured to form a seal around the shaft-handle connector outer surface 846. 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 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 components in combination with one or more O-rings (or another sealing means) configured to seal via plastic deformation of the material between the handle 102 and the shaft-handle connector 103.

The cryoablation system 100 may also include a securing means to secure the shaft-handle connector 103 to the handle. In the example of fig. 6-8, the shaft-handle connector 103 includes a fastener 638. The fastener 638 is configured to rest on the connector protrusion 848 of the shaft-handle connector 103 and to be secured to the 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 securing means configured to securely and removably attach the shaft-handle connector 103 to the handle 102 may be used.

As best shown in fig. 8, 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 that are in fluid communication with the vacuum chamber connector portion 847. The vacuum opening 854 is configured to connect to a vacuum chamber handle portion 849 that is connected to the 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 an operator of the cryoablation system to isolate the expanding precooler gas in 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.

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

In some embodiments, the vacuum source 114 is an active vacuum. For example, the vacuum source 114 may be a vacuum pump or the like. The vacuum pump may be in operative communication with the vacuum chamber 336. The vacuum chamber is configured to prevent heat transfer by creating a low pressure environment between the return tube 326 and the isolated shaft 328 in the isolated region of the shaft. Alternatively, the vacuum source may be a passive vacuum, such as a vacuum sleeve or the like. The vacuum sleeve is typically composed of two layers of material (inner and outer), separated by a vacuum or low pressure gap.

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 opening 856 is configured to be connected to the working gas exhaust 118. The working gas opening 856 is also in fluid communication with an isolated portion of the working gas circuit 210 such that the working gas flows back through the shaft after expanding in the expansion chamber 106 of the shaft 104 and is then exhausted through the working gas exhaust 118 via the working gas opening 856 in the shaft-handle connector 103. In some embodiments, the working gas exhaust 118 may be connected to a conduit that carries the working gas exhaust back to the console or other location in the operating room where the working gas exhaust is exhausted into the surrounding environment at the appropriate location. In another embodiment, the working gas discharge 118 may be connected to a conduit that carries the working gas discharge through a chamber that surrounds the conduit containing the precooler gas such that the working gas discharge cools the precooler gas to achieve increased thermal efficiency.

In various embodiments, the shaft-handle connector 103 may include a valve 842. In the example of fig. 6-8, the valve 842 may be a check valve and include a spring 843. However, other suitable types of valves may be used. In various embodiments, the valve 842 may have an open state in which the working gas circuit 210 flows from the handle 102 to the shaft 104 through the tubing 868 of the shaft-handle connector 103 and a closed state in which the working gas circuit 210 cannot flow from the handle 102 to the shaft 104 through the tubing 868 of the shaft-handle connector. In various embodiments, the valve 842 is configured to switch from an open state to a closed state when the shaft 104 and the shaft-handle connector 103 are removed from the handle 102. This feature is configured to prevent working gas from leaking from the handle 102 when the shaft 104 is replaced. Fig. 8 shows the open state of the valve 842 in which the spring 843 is depressed, so that the valve is opened by linear movement caused by the fastener 638 of the shaft-handle connector 103 being screwed onto the handle protrusion 850 of the handle 102. In various embodiments, the valve 842 is moved to an open state by the act of securing the shaft-handle connector 103 in sealing engagement with the handle 102.

Shaft-handle connector (fig. 9-11)

Referring now to fig. 9-11, various views of the shaft-handle connector are shown. Fig. 9 is a schematic side view of a shaft-handle connector according to various embodiments herein. Fig. 10 is a cross-sectional view of a shaft-handle connector according to various embodiments herein. Fig. 11 is an exploded view of a shaft-handle connector according to various embodiments herein.

In various embodiments, the shaft-handle connector 103 may include a first connection 1058 and a second connection 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 an 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 and second connectors 1058, 1060 may be threaded, and the second connector 1060 may be threaded into the first connector 1058. Alternatively, the first connector 1058 and the second connector 1060 may include one or more removable fittings to attach the first connector 1058 to the second connector 1060.

In various embodiments, the second connector 1060 may define a protrusion 1062. The protrusions 1062 of the second connection piece 1060 are configured to extend within cavities 1064 defined within the first connection piece 1058. The second connection 1060 may also include a second cavity 1066. In various embodiments, the second cavity 1066 may be in fluid communication with a pipe 868. For example, the fluid line 868 may form part of the second cavity 1066. The fluid line 868 is configured to receive working gas from the handle 102 and deliver the working gas to the shaft 104 through the closed supply tube 324. The fluid line 868 may include an interior space 1067 surrounded by an interior surface 1069. In various embodiments, the inner surface 1069 is configured to seal to an outer surface of the supply tube near the proximal end of the supply tube. The sealing area between the supply tube 324 and the inner surface 1069 of the fluid line 868 is shown in fig. 12.

The connector may also define a first tube fitting 1052 at the distal end. The connector may also define a second tube fitting 1063. The second tube fitting 1063 may form part of or extend from the projection 1062 of the second connection member 1060 and be disposed within the cavity 1064 of the first connection member 1058. In various embodiments, the first tube fitting 1052 and the second tube fitting 1063 are each configured to be attached to a portion of the shaft 104. Protrusion 1062 includes an inner surface 1070, and inner surface 1070 is configured to seal against an outer surface of the return tube near a proximal end of the return tube. The sealing area between return tube 326 and inner surface 1070 of protuberance 1062 is shown in fig. 12. In various embodiments, the shaft-handle connector 103 is constructed of any suitable material or materials, such as flexible metals, polymers, composites, and the like. In one embodiment, the shaft-handle connector 103 is made of nitinol (NiTi), stainless steel, or the like.

Catheter assembly (fig. 12-13)

Referring now to fig. 12-13, various views of the catheter assembly are shown herein. Fig. 12 is a schematic view of a catheter assembly according to various embodiments herein. Fig. 13 is a cross-sectional view of a catheter assembly according to various embodiments herein. In various embodiments, the catheter assembly 1264 may include a shaft 104 and a shaft-handle connector 103 of the cryoablation system 100. In some embodiments, the catheter assembly 1264 includes components of the cryoablation system that are to be replaced each time a cryoablation procedure is performed.

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

In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the isolation shaft 328. In the example of fig. 12-13, the first tube fitting 1052 of the shaft-handle connector 103 is configured to seal around the proximal end of the isolation shaft 328. In some embodiments, the isolation shaft 328 may be permanently connected to the shaft-handle connector 103. For example, a proximal portion of isolation shaft 328 may fit inside shaft-handle connector 103 and a portion 1366 of first tube fitting 1052 may be melted and reflowed (or coupled by another suitable means) onto an outer surface of isolation shaft 328 to form a seal between isolation shaft 328 and shaft-handle connector 103. In alternative embodiments, the isolation shaft 328 may be removably connected to the shaft-handle connector 103 using any suitable fastening means.

In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the return tube 326. As shown in the example of fig. 13, the inner surface 1070 of the second tube 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 connected to the shaft-handle connector 103. For example, a proximal portion of the return tube 326 may fit inside the shaft-handle connector 103 and a portion 1368 of the second tube fitting 1063 may be melted and reflowed (or coupled by another suitable means) onto an outer surface of the return tube 326 to form a seal between the return tube 326 and the shaft-handle connector 103. In alternative embodiments, the return tube 326 may be removably connected to the shaft-handle connector 103 using any suitable fastening means.

In various embodiments, the shaft-handle connector 103 is configured to form a seal around the outer surface of the supply tube 324. In the example of fig. 12-13, the fluid line 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 line 868 may include an interior space 1067 surrounded by an interior surface 1069, and the interior surface 1069 is configured to seal against an exterior 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 fit inside the shaft handle connector and may be permanently coupled (e.g., by brazing, etc.) to the fluid line 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 means.

Method of operating a cryoablation system (fig. 14)

Many different methods are contemplated herein, including but not limited to manufacturing methods, methods of use, and the like. According to various embodiments herein, aspects of the system/apparatus operations described elsewhere herein may be performed as operations of one or more methods.

Referring now to fig. 14, a method 1400 of operating a cryoablation system is described herein. Method 1400 may include a step 1402 of providing a cryoablation system. In various embodiments, a 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 also 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 and 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 a first shaft-handle connector.

The method 1400 may include a 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 may be removably attached to the handle by a first shaft-handle connector such that the first shaft may be removed from the handle without damaging the handle. Further, the first conduit assembly may be removed from the handle without impeding the ability of the handle to isolate the precooler gas circuit, working gas circuit, vacuum chamber from one another when the conduit assembly is attached to the handle.

In the example of fig. 6-8, the shaft-handle connector 103 may include a fastener 638, and the shaft 104 may be removed from the handle 102 by releasing the fastener (e.g., by unscrewing the fastener from the handle) and disassembling the shaft from the handle. In various embodiments, the 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 performing a cryoablation procedure on a patient.

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

In the example of fig. 12-13, the shaft-handle connector 103 may include a first connector 1058 and a second connector 1060. The protrusions 1062 of the second connection piece 1060 are configured to extend within cavities 1064 defined within the first connection piece 1058. In such embodiments, to attach the shaft 104 to the shaft-handle connector 103, the isolation shaft 328 may be first coupled to the first connector 1058. For example, a proximal portion of isolation shaft 328 may fit inside shaft-handle connector 103 and a portion 1366 of first tube fitting 1052 may be melted on the outer surface of isolation shaft 328 (or coupled by another suitable means) to form a seal between isolation shaft 328 and shaft-handle connector 103.

After attaching the isolation shaft 328 to the first connection 1060, the return conduit 326 and the supply conduit 324 may be coupled to the second connection 1060, and the first connection 1058 may be attached to the second connection 1060. In one embodiment, a proximal portion of the return tube 326 may fit inside the shaft-handle connector 103 and a portion 1368 of the second tube fitting 1063 may be melted (or coupled by another suitable means) on the outer surface of the return tube 326 to form a seal between the return tube 326 and the shaft-handle connector 103. In one embodiment, the fluid line 868 of the shaft-handle connector 103 is configured to seal around the proximal end of the supply tube 324. The first connector 1058 may then be securely attached to the second connector 1060 by any suitable means, such as an interference fit or the like.

After assembly of the second catheter assembly, the second catheter assembly may be removably attached to the distal end of the handle and secured to the handle using fasteners or the like.

The concepts described herein may be applied to and used in connection with the context of the cryoablation systems and components described in the following four U.S. non-provisional patent applications filed 5 months 22 of 2024, which are incorporated herein by reference in their entirety, U.S. non-provisional patent application Ser. No.18/671,489 entitled "Cryoablation CATHETER SHAFT Construction (cryoablation catheter shaft configuration)", U.S. non-provisional patent application Ser. No.18/671,627 entitled "SAFETY DEVICES for Cryoablation Probe (safety device for cryoablation probe)", U.S. non-provisional patent application Ser. No.18/671,727 entitled "DELIVERY SYSTEMS for Cryoablation Device (delivery system for cryoablation device)", and U.S. non-provisional patent application Ser. No.18/671,742 entitled "DISTAL TIP Structure for Cryoablation Probe (distal tip structure for cryoablation probe)".

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 dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and/or" unless the context clearly dictates otherwise.

It should also be noted that, as used in this specification and the appended claims, the phrase "configured" describes a system, apparatus, or other structure constructed or arranged to perform a particular task or to employ a particular configuration. The phrase "configured" may be used interchangeably with other similar phrases such as arrangement and configuration, construction and arrangement, construction, manufacture and arrangement, and the like.

All publications and patent applications in this specification are indicative of the level of ordinary skill in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

As used herein, a numerical range recited by an endpoint shall include all values encompassed within that range (e.g., 2 to 8 includes 2.1, 2.8, 5.3, 7, etc.).

The title as used herein is to conform to the 37 CFR 1.77 specification or otherwise provide a clue to the organization. These headings should not be construed as limiting or restricting the invention described in any claims that may be formed by this disclosure. For example, although the heading refers to "technical field," such claims should not be limited by the text that describes the so-called technical field chosen under the heading. Furthermore, the description of a technology in the "background" is not an admission that the technology is prior art to any of the inventions in this disclosure. The summary of the invention is not to be considered limiting of the invention set forth in the issued claims.

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, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the 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 may be made while remaining within the spirit and scope herein.

Claims

1. A cryoablation system comprising:

A working gas circuit;

A vacuum chamber isolated from the working gas circuit;

A shaft, the shaft comprising along its length:

An isolation region along a proximal length of the shaft, the isolation region comprising 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, and

A working gas expansion chamber distal to the isolation region, wherein the working gas expansion chamber includes an 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 comprises:

A working gas connector structure configured to form a sealed connection with a working gas supply passage in the handle and a working gas discharge passage in the handle;

a vacuum connector structure configured to form a sealed connection with a vacuum chamber portion of the handle, and

Wherein the shaft-handle connector comprises a connector portion of the vacuum chamber that is isolated from a connector portion of the working gas circuit.

2. The cryoablation system of any of claims 1 and 3-13 wherein the shaft comprises 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 an outer surface of the isolation shaft.

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

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

5. The cryoablation system of any of claims 1-4 and 6-13 wherein the second connector of the shaft-handle connector comprises an interior space and an interior surface of the interior space is configured to form a seal around an exterior surface of the supply tube.

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

7. The cryoablation system of any of claims 1-6 and 8-13 wherein the second piece of the shaft-handle connector comprises an interior space and an interior surface of the interior space is configured to form a seal around an exterior surface of the supply tube.

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

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

10. The cryoablation system of any of claims 1-9 and 11-13 wherein the working gas circuit is configured to supply working gas to the working gas expansion chamber from a high pressure, low temperature gas source, the working gas circuit comprising a working gas joule-thomson orifice at which the working gas enters the working gas expansion chamber.

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

12. The cryoablation system of any of claims 1-11 and 13 wherein the shaft is removable from the handle without any compromise to the ability of the handle to isolate the handle portion of the working gas circuit and the handle portion of the vacuum chamber.

13. The cryoablation system of any of claims 1-12 wherein the cryoablation system further comprises a precooler gas circuit isolated from the working gas circuit and the vacuum circuit, wherein the handle comprises a handle portion of the precooler gas circuit, wherein the precooler gas circuit is configured to supply precooler gas to the handle from a high-pressure, low-temperature gas source, the precooler gas circuit comprising a precooler joule-thomson orifice at which the precooler gas enters a precooler expansion chamber.

14. A method of operating a cryoablation system, comprising:

providing a cryoablation system, the cryoablation system comprising:

A working gas circuit;

A first catheter assembly comprising a first shaft and a first shaft-handle connector, the first shaft comprising a first working gas expansion chamber;

A handle including 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;

Detaching the first catheter assembly from the handle;

Attaching a second catheter assembly to the handle, wherein the second catheter assembly comprises a second shaft comprising a second working gas inflation chamber and a second shaft-handle connector, wherein a proximal end of the second shaft is connected to the second shaft-handle connector, wherein the second shaft-handle connector is configured to removably attach a proximal end of the second shaft to a distal end of the handle.

15. The method of claim 14, wherein the working gas circuit is configured to supply working gas from a high pressure, low temperature gas source to the working gas expansion chamber, the working gas circuit comprising a working gas joule-thomson orifice at which the working gas enters the working gas expansion chamber.