Cryogenic devices with venting features

Abstract

To provide devices, systems, and methods for cooling tissues for therapeutic purposes, including nerves for treating pain.SOLUTION: A cryogenic device has: a housing having a cryogen pathway for conducting a cryogen from a cryogen cartridge toward a needle probe, wherein the cryogen is configured to deliver cryotherapy to a target tissue via one or more needles; an auxiliary pathway coupled to the cryogen pathway and exposed to a relatively low-pressure environment; and a movable sealing element configured to seal the cryogen pathway from the auxiliary pathway when the movable sealing element is in a closed position, and further configured to open the cryogen pathway to the auxiliary pathway so as to vent an amount of the cryogen to the relatively low-pressure environment when the movable sealing element is in an open position, wherein the movable sealing element is configured to be moved by a user-actuatable element coupled to the movable sealing element and separately configured to be moved by an automatic pressure relief mechanism.SELECTED DRAWING: Figure 4B

Description

Technical Field

[0001] Cross - reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 942,547, filed on December 2, 2019, the entire disclosure of which is hereby incorporated by reference in its entirety for all purposes.

[0002]

[0002] An apparatus, system, and method for cooling tissue for therapeutic purposes, including nerves for treating pain.

Background Art

[0003]

[0003] The present disclosure generally relates to medical devices, systems, and methods for cryotherapy. More specifically, the present disclosure relates to cryogenically cooling a patient's target tissue to denature, inhibit, remodel, or otherwise affect the target tissue to achieve a desired change in its behavior or composition. Cryogenic cooling of nerve tissue has been shown to be effective in the treatment of various indications, including pain (e.g., occipital and other neuralgias, neuromas, pain of osteoarthritis), spasticity, and joint stiffness. For example, cooling nerve tissue has been found to denature or inhibit the nerves that contribute to these conditions. Cryogenic cooling has also been used to address cosmetic conditions, for example, by suppressing unwanted and / or unsightly effects on the skin (e.g., lines, wrinkles, or cellulite dimples) or other surrounding tissues.

[0004]

[0004] In light of the above, cryogenic devices having needle probes have emerged as one aspect for therapeutically cooling target tissues for treating various indications. The needle probes of such devices are typically inserted into the patient's skin adjacent to the target tissue. Some cryogenic devices may include a coolant that can be injected into the target tissue through the needle openings of their needle probes such that the target tissue is directly cooled by the coolant. Other cryogenic probes can include a closed needle tip, in which case the needle can be cooled (e.g., by a flow of coolant), thereby cooling the target tissue adjacent to the cooled needle by conduction. Cryogenic probes have proven effective in creating cryogenic zones within the target tissue or the surrounding patient with accuracy, convenience, and reliability. The cryogenic zone may be a certain amount of tissue (e.g., the volume of tissue near or around the distal portion of the needle) cooled by one or more needles of the cryogenic probe. For example, the cryogenic zone may be the volume of tissue cooled to freeze the tissue within the volume (e.g., the cryogenic region can be defined by an isotherm of about 0°C (or other appropriate temperature) that can form around the needles of the cryogenic probe).

Summary of the Invention

[0005]

[0005] The present disclosure relates to improved medical devices, systems, and methods. Many of the devices and systems described herein will be beneficial for cryotherapy using cryogenic devices. Various features of such cryogenic devices are described herein.

[0006]

[0006] In some embodiments, the cryogenic device comprises a housing having a coolant path configured to direct coolant from a pressurized coolant cartridge towards a needle probe having one or more needles, the coolant being configured to deliver cryotherapy to a target tissue via the one or more needles, a housing; an auxiliary path coupled to the coolant path and exposed to a relatively low-pressure environment (e.g., the ambient air environment in which the housing is disposed); and a movable sealing element configured to seal the coolant path from the auxiliary path when in a closed position and further configured to open the coolant path to the auxiliary path to discharge a certain amount of coolant to the relatively low-pressure environment when in an open position, the movable sealing element being configured to be moved by a user-operable element coupled to the movable sealing element and separately configured to be moved by an automatic pressure relief mechanism.

[0007]

[0007] In some embodiments, the automatic pressure relief mechanism includes a biasing element configured to apply a biasing force to bias the movable sealing element towards the closed position, the biasing force fixing the movable sealing element against or pressing the movable sealing element against an opening of the auxiliary path, and the movable sealing element being configured to move to the open position when the biasing force is overcome by the pressure in the coolant path exceeding a maximum pressure value. In some embodiments, the biasing element is an elastic element (e.g., a spring) coupled to the movable sealing element.

[0008]

[0008] In some embodiments, the user-operable element is coupled to a bracket element coupled to the movable sealing element, and the user-operable element is configured to be actuated by a user to move the bracket element along a first direction or a second direction. By moving the bracket element along the first direction, the movable sealing element can be moved to the open position, and by moving the bracket element along the second direction, the movable sealing element can be moved to the closed position.

[0009]

[0009] In some embodiments, the cryogenic device may include a locking mechanism configured to lock the coolant cartridge within the cartridge holder of the housing until the movable sealing element is in the open position. In some embodiments, the locking mechanism is configured to lock the coolant cartridge within the cartridge holder until the user-operable element is actuated such that the movable sealing element moves along a first direction, thereby preventing the coolant cartridge from being removed until the movable sealing element moves along the first direction. In some embodiments, the locking mechanism is coupled to a bracket element coupled to the movable sealing element and the user-operable element, and the locking mechanism is configured to lock the coolant cartridge within the cartridge holder until the user-operable element is actuated to move the bracket element along a first direction, thereby preventing the coolant cartridge from being removed until the bracket element moves along the first direction.

[0010]

[0010] In some embodiments, the cryogenic device can include a pressure sensor and a locking mechanism, and the locking mechanism is configured to lock the coolant cartridge within the cartridge holder of the housing until the pressure level detected by the pressure sensor in the coolant path is lower than a threshold pressure value. In some embodiments, the threshold pressure value is less than the maximum pressure value at which the automatic pressure relief mechanism is configured to move the movable sealing element to the open position.

[0011]

[0011] In some embodiments, the movable sealing element may include a conical structure configured to fit within an auxiliary path. The movable sealing element may include a cylindrical portion, a spherical portion, or a hemispherical portion configured to fit within the auxiliary path.

[0012] In some embodiments, the cryogenic device is a housing having a coolant path configured to direct coolant from a pressurized coolant cartridge towards a needle probe having one or more needles, wherein the coolant is configured to deliver cryotherapy to a target tissue via the one or more needles, a secondary path coupled to the coolant path and exposed to a relatively low pressure environment, and a movable sealing element configured to seal the coolant path from the secondary path when in a closed position and further configured to open the coolant path to the secondary path to discharge an amount of coolant to the relatively low pressure environment when the movable sealing element is in an open position. The movable sealing element may be biased towards the closed position by an elastic element, the elastic element being configured to exert an elastic force, the movable sealing element being fixed relative to or pressed against an opening of the secondary path, and the movable sealing element being configured to move to the open position when the elastic force is overcome by the pressure in the coolant path exceeding a maximum pressure value. The movable sealing element may be coupled to a bracket element coupled to a user-actuable element, the user-actuable element being configured to be actuated by a user to move the bracket element along a first direction or a second direction, moving the bracket element along the first direction causes the movable sealing element to move to the open position, and moving the bracket element along the second direction causes the movable sealing element to move to the closed position.

[0013] In some embodiments, a method for replacing a cartridge of a cryogenic device may include operating a user-operable element of the cryogenic device having a coolant path configured to deliver coolant from a first coolant cartridge to a needle probe, the user-operable element being coupled to a movable sealing element adapted to seal the coolant path from an auxiliary path when the movable sealing element is in a closed position, the auxiliary path being coupled to the coolant path and being exposed to a relatively low-pressure environment. The method may include moving the movable sealing element from the closed position to the open position in response to operation of the user-operable element, the movable sealing element being configured to open the coolant path to the auxiliary path such that an amount of coolant is discharged to the relatively low-pressure environment when the movable sealing element is in the open position, and unlocking a first coolant cartridge within a cartridge holder of the cryogenic device by a locking mechanism. The first coolant cartridge may then be removed. In some embodiments, the first coolant cartridge may be replaced with a second coolant cartridge.

[0014]

[0014] In some embodiments, a method for relieving pressure within a cryogenic device may include the step of actuating a user-operable element of the cryogenic device having a coolant path configured to deliver coolant from a first coolant cartridge to a needle probe, the user-operable element being coupled to a movable seal element adapted to seal the coolant path from an auxiliary path when the movable seal element is in a closed position, the auxiliary path being coupled to the coolant path and being exposed to a relatively low-pressure environment. The method may include the step of moving the movable seal element from the closed position to the open position in response to actuation of the user-operable element, the movable seal element being configured to open the coolant path to the auxiliary path such that an amount of coolant is discharged to the relatively low-pressure environment when the movable seal element is in the open position. The method may further include the step of automatically moving the movable seal element when the pressure within the coolant path exceeds a maximum pressure value, the movable seal element being biased toward the closed position by an elastic element, the elastic element being configured to exert an elastic force that presses the movable seal element against the auxiliary path when the pressure within the coolant path is lower than the maximum pressure value, the movable seal element being configured to move to the open position when the elastic force is overcome by the pressure within the coolant path that exceeds the maximum pressure value. The method may further include the step of locking or unlocking a coolant cartridge within a cartridge holder of the cryogenic device with a locking mechanism.

Brief Description of the Drawings

[0015]

Figure 1A

Figure 1B

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 5C

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0016]

[0025] The present disclosure describes cryogenic devices that can be used to deliver cryotherapy to a patient. In some embodiments, the described cryogenic devices can include needles for delivering subcutaneous cryotherapy that targets specific tissues for treating various conditions. For example, the cryogenic device can include needles configured to be inserted near a peripheral nerve to deliver cryotherapy to the peripheral nerve for treating pain, spasm, or other such conditions that can be improved by such treatment. Further information regarding the use of cryotherapy for the relief of pain or spasm can be found in U.S. Patent No. 8,298,216, filed November 14, 2008, U.S. Patent No. 9,610,112, filed March 18, 2014, U.S. Patent No. 10,085,789, filed March 13, 2017, and U.S. Patent Application Publication No. 2019 / 0038459, filed September 14, 2018, the entire disclosures of which are hereby incorporated by reference in their entirety for all purposes. The cryogenic device can also be used for prophylactic treatment such as the destruction or prevention of nerve tumors, as described in U.S. Patent No. 10,470,813, filed March 14, 2016, the entire disclosure of which is hereby incorporated by reference in its entirety for all purposes.

[0017]

[0026] Figures 1A - 1B illustrate an exemplary embodiment of a cryogenic device 100 that includes a coolant cartridge 130 and a cartridge holder 140 for holding a needle probe 110. As shown in the illustrated exemplary embodiment, the cryogenic device 100 may be a self - contained handpiece suitable for being gripped and operated by an operator's hand. In other embodiments, the cryogenic device may include physically separated components. For example, the cryogenic device may include a handpiece that includes a needle probe and a coolant cartridge separated from the handpiece. In some embodiments, the cryogenic device 100 can have a multi - part (e.g., two - part) housing, and the needle probe 110 can be disposed within a separate probe housing that can be coupled to the housing of the handpiece portion. In other embodiments, the needle probe 110 may not be disposed within a separate housing and may be configured to be directly inserted into the housing of the cryogenic device 100. As an example, the cryogenic device 100 in at least some of these embodiments may have a single housing.

[0018]

[0027] In some embodiments, the coolant cartridge 130 may be a disposable cartridge filled with a coolant (e.g., nitrous oxide, fluorocarbon coolant, and / or carbon dioxide). The coolant cartridge 130 may be pressurized so that the internal coolant is maintained at a relatively high pressure. In some embodiments, the cryogenic device 100 may include a cartridge door 120 for accessing the coolant cartridge 130 (e.g., to replace it). The cartridge door 120 may be configured to move from an open position that allows the cartridge holder 140 to receive the coolant cartridge 130 to a closed position that secures the coolant cartridge 130 within the housing of the cryogenic device 100. For example, as shown in FIGS. 1A-1B, the cartridge door 120 may be configured to pivot about a pivot point 125 to allow access to the coolant cartridge 130. In this example, the user can open the cartridge door 120 as shown in FIG. 1A (e.g., when the user notices that the coolant cartridge 130 is empty), remove the coolant cartridge 130 from the cartridge holder 140, insert a new coolant cartridge 130 into the cartridge holder 140, and close the cartridge door 120 as shown in FIG. 1B. In some embodiments, the cryogenic device 100 may include a valve between the coolant cartridge 130 and a coolant path (through which the coolant flows toward the needle probe 110 attached during the treatment cycle to cool the needle probe 110) to seal the coolant from the coolant path (e.g., when no treatment cycle is in progress).

[0019]

[0028] FIG. 2 shows an internal view of an exemplary cryogenic device 100 assembly 200 that includes a coolant cartridge 130 coupled to a chassis 105. In some embodiments, cryogenic device 100 may include a probe receptacle 170 configured to receive a needle probe 110. In some embodiments, probe receptacle 170 may be configured to couple needle probe 110 to coolant cartridge 130 via a coolant path within chassis 105 (not shown in FIG. 2). In some embodiments, probe receptacle 170 may be perforated in chassis 105 of the cryogenic device, and chassis 105 includes at least a portion of the coolant path. For example, chassis 105 may include one or more lumens therein that are coupled to an outlet of coolant cartridge 130, and one or more lumens of chassis 105 may be coupled to probe receptacle 170. In some embodiments, the chassis may include the entire coolant path (e.g., from the outlet of coolant cartridge 130 to probe receptacle 170) within the handpiece portion of cryogenic device 100. The lower portion AA of assembly 200 is shown in dashed lines and is further referenced in the following disclosure.

[0020]

[0029] FIG. 3A is a schematic cross-sectional view of a coolant cartridge 130 coupled to a chassis 105 of an exemplary cryogenic device 100. A lower portion corresponding to the lower portion AA shown in FIG. 2 is shown. In the example shown in FIG. 3A, the coolant cartridge 130 is coupled to a coolant path 360 including, for example, coolant path portions 360a, 360b, and 360c. A valve 305 may be disposed between the coolant within the cartridge 130 and the probe receptacle 170 (e.g., along the coolant path 360), such that the flow of coolant to the needle probe 110 coupled to the probe receptacle 170 may be controlled by opening and closing the valve 305. In the example shown, when the valve 305 is open, coolant can flow through the coolant path (e.g., coolant path portion 360c) toward the probe receptacle 170. In some embodiments, the cryogenic device 100 may include one or more filtration devices along the coolant path for filtering impurities in the coolant. For example, as shown in FIG. 3A, a filter 350 may be disposed along the coolant path 360 such that the coolant passes through the filter 350 before proceeding. The filtration device may be used to remove impurities (e.g., as a result of puncturing the cartridge to access the refrigerant during manufacture, or impurities that may be introduced into the coolant from the environment in which the cryogenic device 100 is used). Solid impurities can potentially impair the performance of the cryogenic device by clogging the path and / or forming leak paths within the sealing mechanism. Both liquid and gaseous fluid impurities such as oil, water, oxygen, nitrogen, and carbon dioxide can also be present within the coolant cartridge. These impurities can also potentially clog or restrict the coolant path and / or chemically change the properties of the refrigerant. The filtration device may include elements for capturing solids and / or elements for capturing fluids. The filtration device can include any suitable combination of particulate filters and / or molecular filters. Further information regarding the filters of the cryogenic device can be found in U.S. Patent No. 9,155,584, filed Jan. 14, 2013, which is hereby incorporated by reference in its entirety for all purposes.In some embodiments, the filter 139 may be replaceable (e.g., by replacing the piercing element 135 or simply by replacing the filter 139).

[0021]

[0030] Referring to the example of FIG. 3A, the coolant can flow through the filter 350 through the path portion 360b and continue towards the probe receptacle 170 via the coolant path portion 360c. This flow is indicated by the arrow 365.

[0022]

[0031] In some embodiments, as shown in FIG. 3A, the cryogenic device 100 may also include an auxiliary path 330. In some embodiments, the auxiliary path 330 can be used to discharge a quantity of coolant from the cryogenic device 100. The auxiliary path 330 may be exposed to a relatively low-pressure environment (compared to the coolant path), such that the coolant within the auxiliary path is automatically discharged when it is unobstructed. For example, referring to FIG. 3A, the auxiliary path 330 may be open at its distal end to the ambient air environment (e.g., the environment in which the housing of the cryogenic device 100 is disposed). In some embodiments, as shown in FIG. 3A, the movable sealing element 310 can be disposed within or near the auxiliary path 330 such that when the movable sealing element 310 is in the closed position, it seals the coolant path from the auxiliary path 330. The movable sealing element 310 may be further configured to move to an open position. By moving the movable sealing element 310 to the open position, the coolant path can be opened to the auxiliary path 330, and a quantity of coolant at a relatively low pressure can be discharged from the cryogenic device 100 via the auxiliary path 330. Although the present disclosure has illustrated and described the movable sealing element 310 as sealing the entire auxiliary path 330 from the coolant path 360, the present disclosure contemplates that the movable sealing element 310 can be disposed at a location external to the auxiliary path 330 or even above the auxiliary path 330 such that it serves to seal the coolant within the cryogenic device 100 when in the closed position and discharge the coolant from the cryogenic device 100 when in the open position.

[0023]

[0032] Figure 3B shows a cross-section of the lower portion AA shown in Figure 2. As shown, coolant cartridge 130 is coupled to coolant path portion 360a. In the example shown, coolant path portion 360a includes a lumen drilled through piercing element 370 of cryogenic device 100. Piercing element 370 may have a sharp piercing point configured to penetrate a portion (e.g., a membrane) of coolant cartridge 130 to allow coolant from coolant cartridge 130 to flow out of coolant cartridge 130 into coolant path 360. For example, coolant may flow into coolant path portion 360a shown in Figure 3B. In this example, the coolant may then flow through filter 350 into coolant path portion 360b. During normal use, the coolant can then flow through coolant path portion 360c and out into needle probe 110 attached via probe receptacle 170. (The cross-sectional view of Figure 3B does not allow illustration of the connection between coolant path portion 360b and coolant path portion 360c in an exemplary cryogenic device 100.) In the example shown in Figure 3B, movable seal element 310 seals auxiliary path 330 from coolant path portion 360b by being in the closed position. In this example, movable seal element 310 is coupled to bracket element 340, and the bracket element is coupled to spring 320 that provides a biasing force in the proximal direction to bias movable seal element 310 toward the closed position.

[0024]

[0033] Figure 3C is an internal view of the lower portion AA shown in Figure 2 and shows a portion of coolant path 360 and auxiliary path 330. As shown by arrow 365 in the example of Figure 3C, during normal use when flowing coolant to the attached needle probe 110, the coolant flows through coolant path portions 360b, 360c (360a is omitted in this figure). As described above, valve 305 (e.g., disposed along coolant path portion 360b) may be operated to control the flow of coolant within coolant path 360. In this example, the coolant exits chassis 105 via probe receptacle 170 and enters the attached needle probe 110 (not shown).

[0025]

[0034] Figure 4A is an external view of the lower part AA shown in Figure 2, showing the movable sealing element 310 in the closed position. Figure 4B shows the movable sealing element 310 in the open position. As shown, the movable sealing element 310 in the closed position (Figure 4A) serves to prevent the flow of coolant from the auxiliary path 330, and the movable sealing element 310 in the open position (Figure 4B) allows the flow of coolant from the auxiliary path 330. In some embodiments, the movable sealing element 310 may be configured to be moved by an automatic pressure relief system. The movable sealing element 310 may be biased towards the closed position by a biasing force that fixes the movable sealing element 310 against or presses it against the opening of the auxiliary path 330. The biasing force may be provided by an elastic element such as a spring. For example, as shown in Figure 4A, a spring 320 configured to engage the movable sealing element 310 can provide a biasing force to press the movable sealing element 310 against the auxiliary path 330. In some embodiments, alternatively or additionally, the movable sealing element 310 itself may be an elastic elastic component (e.g., a shape memory component such as a leaf spring) fixed to the chassis 105, for example, and biased towards the closed position. In some embodiments, the movable sealing element 310 may be configured to move to the open position when the biasing force is overcome by the pressure applied by the pressurized coolant within the cryogenic device 100. For example, referring to Figures 4A - 4B, the biasing force provided by the spring 320 can be overcome when the pressure in the coolant path 360 exceeds the maximum pressure value. This maximum pressure value may be, for example, 1700 psi. In this example, according to Hooke's law F = -kx, the spring constant k of the spring 320 can be set such that the force F provided by the pressure at the maximum pressure value compresses the spring by a predetermined distance x to discharge the coolant. When the pressure in the coolant path 360 has sufficiently decreased from the discharge, the biasing force is no longer overcome, and the movable sealing element 310 can return to the closed position. There are many examples where the described automatic pressure relief system is advantageous. For example, when the cryogenic device 100 is placed in a very high temperature environment, the pressure within the cryogenic device 100 may rise above the maximum pressure value.As another example, the cryogenic device 100 may include a cartridge heater for heating the coolant cartridge 130, for example, to help create uniform coolant conditions to stabilize the cryogenic pressure and thereby enable consistent cryogenic region formation during cryotherapy treatment. In this example, due to a malfunction of the heater (e.g., something that causes an excessive amount of heat to be applied to the cartridge heater), the pressure may rise above the maximum pressure value. Further information regarding cryogenic devices having a cartridge heater for heating a coolant cartridge can be found in U.S. Patent No. 9,066,712, filed December 22, 2009 (Docket No. 002310US), which is hereby incorporated by reference in its entirety for all purposes. As another example, valve malfunction can cause accumulation of coolant within the coolant path 360 (e.g., referring to FIG. 3A, preventing or reducing the coolant from advancing distally beyond the valve 305), which, in combination with an otherwise acceptable amount of heat being applied by the cartridge heater, can result in pressure buildup exceeding the maximum pressure value. In these examples, raising the pressure to the maximum pressure value may not be safe and / or may damage the cryogenic device 100. Thus, an automatic pressure relief system can be an important feature for the cryogenic device 100.

[0026]

[0035] In some embodiments, the movable sealing element may be separately configured to be moved manually. For example, as shown in FIGS. 4A-4B, the cryogenic device 100 can include a bracket element 340 coupled to the movable sealing element 310, and moving the bracket element 340 causes the movable sealing element 310 to move as well. In some embodiments, the bracket element 340 may be configured to move in a first direction and a second direction. These directions may be along the axis of the cryogenic device 100 (e.g., the longitudinal axis). In this example, moving the bracket element 340 in the first direction (e.g., the distal direction) causes the movable sealing element 310 to move in the first direction (e.g., the distal direction), and moving the bracket element 340 in the second direction (e.g., the proximal direction) causes the movable sealing element 310 to move in the second direction (e.g., the proximal direction). Thus, the bracket element 340 can be used to move the movable sealing element 310 between an open position and a closed position. For example, referring to FIGS. 4A-4B, by moving the bracket element 340 (and correspondingly, the movable sealing element 310) in the distal direction, the movable sealing element 310 can be moved to the open position, thereby enabling the coolant in the coolant path 360 to be discharged through the auxiliary path 330. Similarly, moving the bracket element 340 (and correspondingly, the movable sealing element 310) in the proximal direction causes the movable sealing element 310 to move to the closed position, thereby sealing the auxiliary path 330. In some embodiments, as shown in FIGS. 4A-4B, the bracket element 340 may be coupled to a user-actuable element 345 (or the user-actuable element 345 and the bracket element 340 may be a single integral component) that allows the user to manually move the bracket element 340 as described above. The user-actuable element 345 may be, for example, a slider element configured to move in a first direction (e.g., distal) and a second direction (e.g., proximal) as shown in FIGS. 4A-4B, or any other suitable element for receiving a user input (e.g., a mechanical button disposed on an external housing of the cryogenic device 100, a virtual button disposed on an LCD screen coupled or associated with the cryogenic device 100, etc.).In some embodiments, the user-actuable element 345 may be biased (e.g., using a biasing element) toward a position corresponding to the movable seal element 310 being in the closed position. For example, referring to FIGS. 4A-4B, when the user slides and applies a force to hold the user-actuable element 345 in the distal position, the movable seal element 310 moves to the open position and can remain there as long as the user continues to hold the user-actuable element 345 in the distal position. In this example, when the user releases the user-actuable element 345, the user-actuable element 345 automatically returns to the proximal position, thereby moving the movable seal element 310 to the closed position. In other embodiments, the user-actuable element 345 may not be biased, in which case the user having the actuable element 345 (and correspondingly, the movable seal element 310) maintains its position (proximal or distal) until further actuation by the user. Although the present disclosure focuses on user-actuable element 345 and movable seal element 310 configured to move in the distal and proximal directions, these elements can move in any suitable direction as long as the purpose of moving the movable seal element 310 between the open and closed positions is achieved.

[0027]

[0036] Manual means for moving the movable sealing element 310 can be useful in several different scenarios. For example, the user can manually move the movable sealing element 310 before removing the coolant cartridge 130 so as to discharge the coolant within the coolant path 360. This can enhance the safety of the device by reducing the risk associated with removing the coolant cartridge 130 while pressurized coolant still exists within the coolant path 360. Referring to the exemplary cryogenic device 100 shown in FIG. 3A, before removing the cartridge 130, the user can manually move the movable sealing element 310 to the open position to enable the coolant within the coolant path 360 (e.g., the coolant within the coolant path 360 proximal to the valve 305) to be discharged via the auxiliary path 330. This can reduce the pressure within the coolant path 360 leading to the coolant cartridge 130 and / or bring it to ambient temperature, enabling the safe removal of the coolant cartridge 130. In some embodiments, as in the example illustrated in FIG. 3A, the auxiliary path 330 may be disposed upstream of the valve 305 to ensure that all of the coolant within the coolant path (at least leading to the coolant cartridge 130) has the opportunity to be discharged from the cryogenic device via the auxiliary path 330. As another example of a scenario where manual means for moving the movable sealing element 310 can be useful, the user can manually move the movable sealing element 310 after determining (e.g., based on data from a pressure sensor) that the pressure within the coolant path 360 exceeds a desired pressure value (e.g., when the pressure value is not high enough to overwhelm the biasing force for automatic pressure relief, when there is a malfunction in the automatic pressure relief mechanism, etc.).

[0028]

[0037] While the present disclosure focuses on a particular exemplary mechanism for moving the movable sealing element 310, other suitable means for moving the movable sealing element 310 are contemplated. For example, the movable sealing element 310 may be moved by an electronic component such as a rotary motor or a linear actuator. The electronic component can receive pressure data from a pressure sensor within the coolant path 360 and can automatically operate to move the movable sealing element 310. Additionally or alternatively, the electronic component can receive a signal (e.g., an electrical signal) when a user actuates a user-actuable element 345 (e.g., a mechanical or virtual button external to the cryogenic device), and in response, operate the electronic component to move the movable sealing element 310.

[0029]

[0038] The configuration shown in the exemplary embodiments of FIGS. 4A - 4B is advantageous in that it integrates two separate means for relieving overpressure from the cryogenic device 100 into a single combined mechanism. Such integration results in both a reduction in the complexity and a reduction in the footprint of the cryogenic device 100 (e.g., due to the lack of redundancy that would otherwise exist with two separate mechanisms).

[0030]

[0039] Figures 5A - 5C show an exemplary embodiment of the movable sealing element 310. The movable sealing element 310 is dimensioned to efficiently seal the auxiliary path 330 and to be efficiently coupled to one or more mechanisms (e.g., bracket 340, spring 320) for moving the movable sealing element 310. Figure 5A shows a movable sealing element 310 having a conical first portion 510, a cylindrical second portion 520, and a coupling portion 530 (e.g., for coupling with the bracket 340 and spring 320 of Figures 4A - 4B). Figure 5B shows a movable sealing element 310 having a cylindrical first portion 510 and a coupling portion 530. Figure 5C shows a hemispherical first portion 510, a cylindrical second portion, and a coupling portion 530. Figures 5A - 5C show a movable sealing element 310 having a specific number of portions, but the present disclosure contemplates any number of portions. Further, Figures 5A - 5C show the different portions as separate, but the present disclosure is intended to cover the possibility that one or more of the portions may be integrated (e.g., referring to Figure 5A, portions 510, 520, and 530 may be a single integral component). Additionally, Figures 5A - 5C show a specific shape of a portion of the movable sealing element 310, but any suitable shape (e.g., spherical, cubical, pyramidal) can be used.

[0031]

[0040] In some embodiments, the cryogenic device 100 can include a locking mechanism configured to lock the coolant cartridge 130 within the cartridge holder 140 until the movable sealing element 310 is in the open position. By having such a locking mechanism, additional safety can be provided to the user of the cryogenic device 100 by preventing the user from removing the coolant cartridge 130 until an exit path exists for any pressurized coolant that may be present in the coolant path 360. If the coolant cartridge 130 is removed while high-pressure coolant is accumulated within the coolant path 360, the coolant may be forced out of the coolant path 360 (e.g., proximally) in an unsafe manner. The locking mechanism can force the user to move the movable sealing element 310 to the open position (e.g., by actuating the user-actuable element 345), whereby any coolant within the coolant path 360 can begin to be discharged via the auxiliary path 330 (and having a second exit path via the auxiliary path 330), at least prior to the coolant cartridge 130 being removed. In some embodiments, the locking mechanism may require that the movable sealing element 310 be held in the open position for a predetermined period (e.g., as a safety measure to ensure that a certain amount of accumulated coolant is discharged). For example, a timer may be started when the user actuates the user-actuable element 345, and the coolant cartridge 130 may be unlocked from the cartridge holder 140 only after a predetermined period has elapsed.

[0032]

[0041] Any suitable means can be used to ensure that the movable sealing element 310 is in the open position (or has been in the open position for a predetermined period). In some embodiments, the locking mechanism may be configured to unlock the coolant cartridge 130 when an element coupled to the movable sealing element 310 is moved. For example, the locking mechanism may include a retaining element coupled to the movable sealing element 310 (or a portion thereof) that can act as a barrier (e.g., a mechanical barrier) to prevent removal of the coolant cartridge 130. In this example, by moving the movable sealing element 310 to the open position, the retaining element can be moved to unlock the coolant cartridge 130 from the cartridge holder 140. In some embodiments, the coolant cartridge may not be removable until an input element (e.g., an unlock button) is actuated to unlock the coolant cartridge 130. In some embodiments, the input element may be the user-operable element 345, in which case the user-operable element 345 may be actuated (e.g., by sliding the user-operable element 345 in the distal direction to move the movable sealing element 310 to the open position, see FIGS. 4A - 4B). In some of these embodiments, a retaining element coupled to the user-operable element 345 (or a portion thereof) can function as a barrier (e.g., a mechanical barrier) to prevent removal of the coolant cartridge 130. By actuating the user-operable element 345, the retaining element can be moved to unlock the coolant cartridge 130 from the cartridge holder 140. In some embodiments, the locking mechanism may be coupled to an element such as the bracket element 340 of FIGS. 4A - 4B coupled to the movable sealing element 310. The locking mechanism may be configured to lock the coolant cartridge within the cartridge holder until the bracket element 340 is moved. In some of these embodiments, a retaining element coupled to the bracket element 340 (or a portion thereof) can act as a barrier (e.g., a mechanical barrier) to prevent removal of the coolant cartridge 130.Moving the bracket element 340 (e.g., referring to FIGS. 4A-4B, moving the user-actuable element 345 to move the bracket element 340 distally) moves the retaining element to unlock the coolant cartridge 130 from the cartridge holder 140.

[0033]

[0042] In some embodiments, the locking mechanism is configured to lock the coolant cartridge 130 within the cartridge holder 140 until the pressure level in the coolant path 360 drops below a threshold pressure value. For example, the locking mechanism can operate electronically to be able to receive a pressure signal from a pressure sensor in the coolant path 360. In this example, the locking mechanism can lock the coolant cartridge 130 when receiving a pressure signal indicating that the pressure in the coolant path 360 is at or above the threshold pressure value. As another example, the locking mechanism may operate mechanically to lock the coolant cartridge 130 when the pressure level in the coolant path 360 is at or above the threshold pressure value. An example of a means to achieve this may be an elastic element such as a spring configured to press the retaining element against the coolant cartridge 130 when the pressure is at or above the threshold pressure value (the configuration of the movable seal element 310 and the spring 320 operates in a manner similar to but opposite to the way shown in FIGS. 4A-4B). In some embodiments, the threshold pressure level may be equal to the maximum pressure value (i.e., the value at which the movable seal element 310 is configured to move to the open position). In other embodiments, the threshold pressure level may be less than the maximum pressure value. In these embodiments, the threshold pressure level can functionally set a higher safety standard (compared to the maximum pressure value) for removing the coolant cartridge 130. In yet other embodiments, it may be the opposite, in which case the threshold pressure level may be greater than the maximum pressure value.

[0034]

[0043] FIG. 6 shows an exemplary method 600 for replacing a cartridge of a cryogenic device. The method may include, at step 610, operating a user-operable element of the cryogenic device having a coolant path configured to deliver coolant from a first coolant cartridge to a needle probe, the user-operable element being coupled to a movable seal element adapted to seal the coolant path from an auxiliary path when the movable seal element is in a closed position, the auxiliary path being coupled to the coolant path and being exposed to a relatively low pressure environment. At step 620, the method may include moving the movable seal element from a closed position to an open position in response to operation of the user-operable element, the movable seal element being configured to open the coolant path to the auxiliary path such that an amount of coolant is discharged to the relatively low pressure environment when the movable seal element is in the open position. At step 630, the method may include unlocking a first coolant cartridge within a cartridge holder of the cryogenic device by a locking mechanism in response to operation of the user-operable element. At step 640, the method may include removing the first coolant cartridge. In some embodiments, the method may include positioning a second coolant cartridge within the cartridge holder such that the locking mechanism automatically secures the second coolant cartridge in place. For example, the locking mechanism may be snap-fitted into place when the second coolant cartridge is properly positioned. In other embodiments, the method may include placing the second coolant cartridge within the cartridge holder and operating an input element (e.g., user-operable element 345) to cause the locking mechanism to secure the second coolant cartridge in place.

[0035]

[0044] Certain embodiments can, where appropriate, repeat one or more steps of the method of FIG. 6. Although the present disclosure describes and illustrates specific steps of the method of FIG. 6 as occurring in a particular order, the present disclosure contemplates any suitable steps of the method of FIG. 6 occurring in any suitable order. Further, although the present disclosure describes and illustrates an exemplary method for replacing a cartridge of a cryogenic device that includes specific steps of the method of FIG. 6, the present disclosure contemplates any suitable method for replacing a cartridge of a cryogenic device that includes any suitable steps, all, some, or none of the steps of the method of FIG. 6, as necessary. Further, although the present disclosure describes and illustrates specific components, devices, or systems for performing specific steps of the method of FIG. 6, the present disclosure contemplates any suitable combination of any suitable components, devices, or systems for performing any suitable steps of the method of FIG. 6.

[0036]

[0045] FIG. 7 is a simplified schematic view of a cryogenic device 100 in use. As shown, the needle 115 can be inserted into and out of the patient's skin 710 such that the distal portion of the needle 115 is adjacent to the target tissue (e.g., nerve tissue). In some embodiments, the operator can select the needle probe such that when the tissue engagement surface 720 contacts the skin 710, the needle 115 extends distally beyond non-target tissue and is sized to be adjacent to the target tissue. In some embodiments, once the needle 115 is positioned, the operator can submit an input to the cryogenic device 100 (e.g., by actuating a button, tapping a user interface element on a touch screen, etc.) to cause the controller to open the supply valve 122, thereby allowing coolant to flow from the cartridge 130 through the coolant path into the lumen of the needle 115. The needle 115 may be configured such that the distal portion of the needle 115 is cooled more than the proximal portion of the needle 115. Thus, the distal portion of the needle 115 can form a cooling zone around the target tissue, as shown in FIG. 7.

[0037]

[0046] The exemplary embodiments have been described in some detail for purposes of clarity of understanding and as examples, but some modifications, changes, and adaptations may be made and / or would be apparent to those skilled in the art. Accordingly, the scope of the present invention is limited only by the following claims.

Claims

[Claim 1] 1. A cryodevice for administering cryotherapy to a target tissue of a patient, comprising: a housing including a coolant pathway configured to direct coolant from a pressurized coolant cartridge toward a needle probe including one or more needles, the coolant configured to deliver cryotherapy to a target tissue through the one or more needles; an auxiliary passageway coupled to the coolant passageway and exposed to a relatively low pressure environment; a movable sealing element configured to seal the coolant pathway from the auxiliary pathway when the movable sealing element is in a closed position and further configured to open the coolant pathway to the auxiliary pathway to exhaust a quantity of the coolant to the relatively low pressure environment when the movable sealing element is in an open position, the movable sealing element configured to be moved by a user-actuable element coupled to the movable sealing element and separately configured to be moved by an automatic pressure release mechanism; Cryogenic equipment including:

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