Cryogenic equipment with exhaust function

Abstract

1. A cryogenic device comprising: a housing having a coolant pathway for directing coolant from a coolant cartridge toward a needle probe, the coolant configured to deliver cryotherapy to a target tissue through one or more needles; an auxiliary pathway coupled to the coolant pathway and exposed to a relatively low-pressure environment; and 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 so as to discharge a quantity of 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.

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 incorporated herein 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 undesirable and / or unsightly effects on the skin (e.g., lines, wrinkles, or cellulite dimples) or other surrounding tissues.

[0004] In light of the above, cryodevices with needle probes have emerged as one way to therapeutically cool target tissue for treating various indications. The needle probes of such devices are typically inserted into a patient's skin adjacent to the target tissue. Some cryodevices may contain a coolant that can be injected into the target tissue through the openings in the needle probes so that the target tissue is directly cooled by the coolant. Other cryoprobes may include closed needle tips, in which case the needles can be cooled (e.g., by a flow of coolant), thereby cooling the target tissue adjacent to the cooled needles by conduction. Cryoprobes have proven effective in creating a cryozone within a patient at or around a target tissue with precision, convenience, and reliability. The cryozone may be a volume of tissue cooled by one or more needles of the cryoprobe (e.g., a volume of tissue near or around the distal portion of the needles). For example, the cryozone may be a volume of tissue that is cooled to freeze the tissue within the volume (e.g., a cryozone may be defined by an isotherm of approximately 0°C (or other suitable temperature) that can form around the needles of the cryoprobe). 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 may be useful in cryotherapy using cryogenic devices. Various features of such cryogenic devices are described herein.

[0006]

[0006] In some embodiments, the cryogenic device may include a housing having a coolant pathway configured to direct coolant from a pressurized coolant cartridge toward a needle probe having one or more needles, the coolant configured to deliver cryotherapy to the target tissue through the one or more needles; an auxiliary pathway coupled to the coolant pathway and exposed to a relatively low-pressure environment (e.g., an ambient air environment in which the housing is located); and 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 so as to discharge a quantity of 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.

[0007] In some embodiments, the automatic pressure release mechanism includes a biasing element configured to apply a biasing force to bias the movable sealing element toward the closed position, the biasing force securing the movable sealing element against or pressing the opening of the auxiliary passage, and the movable sealing element configured to move to the open position when the biasing force is overcome by pressure in the coolant passage that exceeds a maximum pressure value. In some embodiments, the biasing element is a resilient element (e.g., a spring) coupled to the movable sealing element.

[0008] In some embodiments, the user-actuatable element is coupled to a bracket element coupled to the movable sealing element, the user-actuatable 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 can move the movable sealing element to an open position, and moving the bracket element along the second direction can move the movable sealing element to a 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 to move the movable sealing element 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 supplemental path coupled to the coolant path and exposed to a relatively low pressure environment, and a movable seal element configured to seal the coolant path from the supplemental path when in a closed position and further configured to open the coolant path to the supplemental path to discharge an amount of the coolant to the relatively low pressure environment when the movable seal element is in an open position. The movable seal element may be biased towards the closed position by an elastic element, the elastic element being configured to exert an elastic force, the movable seal element being fixed relative to or pressed against an opening of the supplemental path, and the movable seal 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 seal 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 seal element to move to the open position, and moving the bracket element along the second direction causes the movable seal element to move to the closed position.

[0013] In some embodiments, a method for replacing a cartridge in a cryogenic device may include activating a user-actuatable element of a cryogenic device having a coolant pathway configured to deliver coolant from a first coolant cartridge to a needle probe, the user-actuatable element coupled to a movable sealing element adapted to seal the coolant pathway from an auxiliary pathway when the movable sealing element is in a closed position, the auxiliary pathway coupled to the coolant pathway and exposed to a relatively low-pressure environment. In response to activation of the user-actuatable element, the movable sealing element may move from the closed position to an open position, the movable sealing element configured to open the coolant pathway to the auxiliary pathway so as to discharge a quantity of coolant to the relatively low-pressure environment when the movable sealing element is in the open position, and causing a locking mechanism to unlock the first coolant cartridge in a cartridge holder of the cryogenic device. 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 operating a user-actuable element of the cryogenic device having a coolant path configured to deliver coolant from a first coolant cartridge to a needle probe, the user-actuable 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 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-actuable 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. The method may further include automatically moving the movable sealing element when the pressure within the coolant path exceeds a maximum pressure value, the movable sealing 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 sealing element against the auxiliary path when the pressure within the coolant path is lower than the maximum pressure value, the movable sealing element being configured to move to the open position when the elastic force is overcome by the pressure within the coolant path exceeding the maximum pressure value. The method may further include 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

[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 to treat pain, spasm, or other such conditions that can be improved by such treatment. Further information regarding the use of cryotherapy for pain or spasm relief 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 incorporated herein by reference in their entirety for all purposes. The cryogenic device can also be used for prophylactic treatment such as 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 incorporated herein by reference in its entirety for all purposes.

[0017]

[0026] Figures 1A - 1B show an exemplary embodiment of a cryogenic device 100 that includes a coolant cartridge 130 and a cartridge holder 140 for holding the needle probe 110. As shown in the illustrated exemplary embodiment, the cryogenic device 100 may be a self - contained handpiece suitable for being grasped 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, a fluorocarbon refrigerant, and / or carbon dioxide). The coolant cartridge 130 may be pressurized so that the coolant therein 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, which allows the cartridge holder 140 to accept the coolant cartridge 130, to a closed position, which 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, a user can open the cartridge door 120 as shown in FIG. 1A (e.g., when the user realizes 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 the coolant pathway (through which coolant flows toward the attached needle probe 110 during a treatment cycle to cool the needle probe 110) to seal the coolant from the coolant pathway (e.g., when a treatment cycle is not occurring).

[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 simplified cross-sectional schematic diagram of a coolant cartridge 130 coupled to the chassis 105 of the exemplary cryogenic device 100. A subsection corresponding to subsection AA shown in FIG. 2 is shown. In the example shown in FIG. 3A, the coolant cartridge 130 is coupled to a coolant pathway 360, including, for example, coolant pathway portions 360a, 360b, and 360c. A valve 305 may be disposed between the coolant in the cartridge 130 and the probe receptacle 170 (e.g., along the coolant pathway 360), such that the flow of coolant to the needle probe 110 coupled to the probe receptacle 170 may be controlled by opening or closing the valve 305. In the illustrated example, when the valve 305 is open, coolant can flow through the coolant pathway (e.g., coolant pathway portion 360c) toward the probe receptacle 170. In some embodiments, the cryogenic device 100 may include one or more filtration devices along the coolant pathway for filtering impurities in the coolant. For example, as shown in FIG. 3A, a filter 350 may be positioned along the coolant path 360 so that the coolant passes through the filter 350 before proceeding. The filtration device may be used to remove impurities (e.g., impurities that may be introduced into the coolant during manufacturing, as a result of puncturing the cartridge to access the coolant, or from the environment in which the cryogenic device 100 is used). Solid impurities can impair the performance of the cryogenic device by blocking the path and / or creating leak paths in the sealing mechanism. Fluid impurities, both liquid and gaseous, such as oil, water, oxygen, nitrogen, and carbon dioxide, may also be present in the coolant cartridge. These impurities can also block or restrict the coolant path and / or chemically alter the properties of the refrigerant. The filtration device may include elements for capturing solids and / or elements for capturing fluids. The filtration device may include any suitable combination of particulate filters and / or molecular filters. Further information regarding cryogenic equipment filters can be found in U.S. Patent No. 9,155,584, filed January 14, 2013, which is incorporated herein 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 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 certain amount 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), and as a result, the coolant within the auxiliary path is automatically discharged when it is not blocked. 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 the 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 certain amount of coolant in a relatively low-pressure environment can be discharged from the cryogenic device 100 via the auxiliary path 330. Although the present disclosure illustrates and describes 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 position 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] FIG. 3B shows a cross section of the lower portion AA shown in FIG. 2 . As shown, the coolant cartridge 130 is coupled to the coolant pathway portion 360a. In the illustrated example, the coolant pathway portion 360a includes a lumen drilled through a puncture element 370 of the cryogenic device 100. The puncture element 370 may have a sharp puncture point configured to penetrate a portion (e.g., a membrane) of the coolant cartridge 130 to allow coolant from the coolant cartridge 130 to flow out of the coolant cartridge 130 into the coolant pathway 360. For example, coolant may enter the coolant pathway portion 360a shown in FIG. 3B . In this example, the coolant may then flow through the filter 350 to the coolant pathway portion 360b. During normal use, the coolant may then flow through the coolant pathway portion 360c and out to the attached needle probe 110 via the probe receptacle 170. (The cross-sectional view of FIG. 3B does not allow for illustration of the connection between coolant path portion 360b and coolant path portion 360c in exemplary cryogenic device 100.) In the example shown in FIG. 3B, movable sealing element 310 is in a closed position, thereby sealing auxiliary path 330 from coolant path portion 360b. In this example, movable sealing element 310 is coupled to bracket element 340, which is coupled to spring 320 that provides a proximal biasing force to bias movable sealing element 310 toward the closed position.

[0024]

[0033] FIG. 3C is an internal view of subsection AA shown in FIG. 2, showing coolant pathway 360 and a portion of auxiliary pathway 330. During normal use, coolant flows through coolant pathway portions 360b and 360c (360a is omitted from this view), as indicated by arrow 365 in the example of FIG. 3C, to flow to the attached needle probe 110. As discussed above, valve 305 (e.g., disposed along coolant pathway portion 360b) may be operated to control the flow of coolant within coolant pathway 360. In this example, coolant exits chassis 105 via probe receptacle 170 and enters 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 to 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, for example, the chassis 105 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 within 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 within the coolant path 360 has sufficiently dropped 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 coolant from advancing distally beyond 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 for manual movement. For example, as shown in FIGS. 4A-4B , the cryogenic device 100 may include a bracket element 340 coupled to the movable sealing element 310, such that moving the bracket element 340 also moves the movable sealing element 310. 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 an axis (e.g., the longitudinal axis) of the cryogenic device 100. In this example, moving the bracket element 340 in a first direction (e.g., distally) moves the movable sealing element 310 in the first direction (e.g., distally), and moving the bracket element 340 in a second direction (e.g., proximally) moves the movable sealing element 310 in the second direction (e.g., proximally). 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, with reference to FIGS. 4A-4B , moving bracket element 340 (and correspondingly, movable sealing element 310) distally can move movable sealing element 310 to an open position, thereby allowing coolant in coolant pathway 360 to vent through auxiliary pathway 330. Similarly, moving bracket element 340 (and correspondingly, movable sealing element 310) proximally can move movable sealing element 310 to a closed position, thereby sealing auxiliary pathway 330. In some embodiments, as shown in FIGS. 4A-4B , bracket element 340 can be coupled to a user-actuable element 345 (or user-actuable element 345 and bracket element 340 can be a single, integral component) that allows a user to manually move 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., distally) and a second direction (e.g., proximally) as shown in Figures 4A-4B, or any other suitable element for receiving user input (e.g., a mechanical button located on the external housing of the cryostat 100, a virtual button located on an LCD screen coupled to or associated with the cryostat 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, a user can manually move the movable sealing element 310 before removing the coolant cartridge 130 to vent the coolant in the coolant pathway 360. This can increase the safety of the device by reducing the risks associated with removing the coolant cartridge 130 while pressurized coolant is still present in the coolant pathway 360. With reference to the exemplary cryogenic device 100 shown in FIG. 3A , before removing the cartridge 130, a user can manually move the movable sealing element 310 to the open position to allow the coolant in the coolant pathway 360 (e.g., the coolant in the coolant pathway 360 proximal to the valve 305) to vent through the auxiliary pathway 330. This can reduce the pressure in the coolant pathway 360 leading to the coolant cartridge 130 and / or allow it to reach ambient temperature, allowing for safe removal of the coolant cartridge 130. 3A , auxiliary path 330 may be located upstream of valve 305 to ensure that all coolant in the coolant path (at least leading to coolant cartridge 130) has an opportunity to exit the cryogenic device via auxiliary path 330. As another example of a scenario in which manual means for moving movable sealing element 310 may be useful, a user may manually move movable sealing element 310 after determining (e.g., based on data from a pressure sensor) that the pressure in coolant path 360 exceeds a desired pressure value (e.g., the pressure value is not high enough to overcome the biasing force for the automatic pressure release, the automatic pressure release mechanism has failed, etc.).

[0028]

[0037] While this 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 may receive pressure data from a pressure sensor in the coolant path 360 and may operate automatically to move the movable sealing element 310. Additionally or alternatively, the electronic component may receive a signal (e.g., an electrical signal) when a user activates a user-actuable element 345 (e.g., a mechanical or virtual button external to the cryogenic device), responsively operating the electronic component to move the movable sealing element 310.

[0029]

[0038] 4A-4B is advantageous in that it integrates two separate means of relieving excess pressure from cryogenic device 100 into a single combined mechanism. Such integration results in both reduced complexity and a reduced footprint of cryogenic device 100 (e.g., due to the lack of redundancy that would otherwise exist in having two separate mechanisms).

[0030]

[0039] 5A-5C illustrate exemplary embodiments of the movable sealing element 310. The movable sealing element 310 may be dimensioned to efficiently seal the auxiliary passage 330 and to efficiently couple with one or more mechanisms (e.g., bracket 340, spring 320) for moving the movable sealing element 310. FIG. 5A illustrates the 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 FIGS. 4A-4B). FIG. 5B illustrates the movable sealing element 310 having the cylindrical first portion 510 and coupling portion 530. FIG. 5C illustrates the hemispherical first portion 510, the cylindrical second portion, and the coupling portion 530. While FIGS. 5A-5C illustrate the movable sealing element 310 with a specific number of portions, the present disclosure contemplates any number of portions. 5A-5C depict different portions as separate, the present disclosure contemplates that one or more of the portions may be integrated (e.g., with reference to FIG. 5A, portions 510, 520, and 530 may be a single, integral component). Additionally, while FIGS. 5A-5C depict particular shapes of portions of movable sealing element 310, any suitable shape (e.g., spherical, rectangular, pyramidal) may be used.

[0031]

[0040] In some embodiments, the cryogenic apparatus 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 apparatus 100 by preventing the user from removing the coolant cartridge 130 until there is an exit path 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 stored in 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 at least begin to drain via the auxiliary path 330 (and having a second exit path via the auxiliary path 330) before the coolant cartridge 130 is 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 drained). For example, a timer may be started when the user actuates the user-actuable element 345, and the coolant cartridge 130 may only be unlocked from the cartridge holder 140 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 a user-operable element 345, in which case the user-operable element 345 may be actuated (e.g., by sliding the user-operable element 345 distally 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.By moving the bracket element 340 (e.g., referring to FIGS. 4A - 4B, moving the user - actuatable element 345 slides the bracket element 340 distally), the retaining element can be moved 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 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 it receives 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 sealing element 310 and the spring 320 operates in a manner opposite to but similar 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 sealing 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 still 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 illustrates an exemplary method 600 for replacing a cartridge in a cryogenic device. The method may include, in step 610, activating a user-actuatable element of a cryogenic device having a coolant pathway configured to deliver coolant from a first coolant cartridge to a needle probe, the user-actuatable element being coupled to a movable sealing element adapted to seal the coolant pathway from an auxiliary pathway when the movable sealing element is in a closed position, the auxiliary pathway being coupled to the coolant pathway and exposed to a relatively low-pressure environment. In step 620, the method may include, in response to activation of the user-actuatable element, moving the movable sealing element from the closed position to an open position, the movable sealing element being configured to open the coolant pathway to the auxiliary pathway to discharge a quantity of coolant to the relatively low-pressure environment when the movable sealing element is in the open position. In step 630, the method may include, in response to activation of the user-actuatable element, causing a locking mechanism to unlock the first coolant cartridge in a cartridge holder of the cryogenic device. In step 640, the method may include removing the first coolant cartridge. In some embodiments, the method may include positioning the second coolant cartridge within the cartridge holder such that a locking mechanism automatically secures the second coolant cartridge in place. For example, the locking mechanism may snap 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 actuating an input element (e.g., user-actuable 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 has described and illustrated certain 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 has described and illustrated an exemplary method for replacing a cartridge of a cryogenic device that includes certain 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 has described and illustrated certain components, devices, or systems for performing certain 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 step of the method of FIG. 6.

[0036]

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

[0037]

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

Claims

1. A cryogenic device for applying cryotherapy to a target tissue of a patient, a housing including a coolant path configured to direct coolant from a pressurized coolant cartridge toward a needle probe including one or more needles, wherein the coolant is configured to deliver cryotherapy to the target tissue via the one or more needles; a supply valve coupled to the coolant path coupled to the needle probe; an auxiliary path coupled to the coolant path and exposed to a relatively low-pressure environment; a movable sealing element configured to seal the auxiliary path when biased to a closed position by a biasing force, and further configured to open the auxiliary path to discharge a certain amount of the coolant into the relatively low-pressure environment to reduce the pressure in the coolant path when the pressure in the coolant path presses the movable sealing element to an open position by a force opposing the biasing force, 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 release mechanism, and the coolant flowing through the supply valve to the needle probe when the movable sealing element is biased to the closed position; a biasing element configured to apply the biasing force to the movable sealing element toward the coolant path, the biasing element being a spring element; comprising; the supply valve is disposed along the coolant path between an opening of the auxiliary path and the needle probe, the cryogenic device.

2. The cryogenic device according to claim 1, wherein the biasing force presses the movable sealing element against the opening of the auxiliary path, and the movable sealing element is configured to move to the open position when the biasing force is overwhelmed by the pressure in the coolant path exceeding a maximum pressure value.

3. The cryogenic device according to claim 2, wherein the biasing element is an elastic element coupled to the movable sealing element.

4. The user-operable element is coupled to a bracket element coupled to the movable sealing element, the user-operable 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, the cryogenic device according to any one of claims 1 to 3.

5. The relatively low-pressure environment is the ambient air environment in which the housing is disposed, the cryogenic device according to any one of claims 1 to 4.

6. Further comprising a locking mechanism, the locking mechanism being configured to lock the coolant cartridge in a cartridge holder of the housing until the movable sealing element reaches the open position, the cryogenic device according to any one of claims 1 to 5.

7. The locking mechanism is configured to lock the coolant cartridge in the cartridge holder until the user-operable element operates to move the movable sealing element along a first direction, thereby preventing the coolant cartridge from being removed until the movable sealing element moves along the first direction, the cryogenic device according to claim 6.

8. The locking mechanism is coupled to a bracket element coupled to the movable sealing element and the user-operable element, the locking mechanism being configured to lock the coolant cartridge in the cartridge holder until the user-operable element operates 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, the cryogenic device according to claim 6.

9. Further comprising a pressure sensor and a locking mechanism, the locking mechanism being configured to lock the coolant cartridge in a cartridge holder of the housing until a pressure level detected by the pressure sensor in the coolant path is lower than a threshold pressure value, the cryogenic device according to any one of claims 1 to 5.

10. The cryogenic device according to claim 9, wherein the threshold pressure value is smaller than the maximum pressure value at which the automatic pressure release mechanism is configured to move the movable sealing element to the open position.

11. The cryogenic device according to any one of claims 1 to 10, wherein the movable sealing element includes a conical portion configured to fit within the auxiliary path.

12. The cryogenic device according to any one of claims 1 to 10, wherein the movable sealing element includes a cylindrical portion, a spherical portion, or a hemispherical portion configured to fit within the auxiliary path.

13. The cryogenic device according to claim 1, wherein the user-operable element is a button.

14. The cryogenic device according to claim 13, wherein the button includes a mechanical or virtual button.

15. A cryogenic device for applying cryotherapy to a target tissue of a patient, a housing including a coolant path configured to direct coolant from a pressurized coolant cartridge toward a needle probe including one or more needles, wherein the coolant is configured to deliver cryotherapy to the target tissue via the one or more needles, a supply valve coupled to the coolant path and coupled to the needle probe, an auxiliary path exposed to a relatively low-pressure environment, a movable sealing element configured to seal the coolant path from the auxiliary path when in the closed position and further configured to open the coolant path to the auxiliary path to discharge an amount of the coolant to the relatively low-pressure environment when in the open position, wherein the movable sealing element is biased toward the closed position by an elastic element, the elastic element is configured to exert an elastic force that presses the movable sealing element against the auxiliary path, the movable sealing element is 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, and when the movable sealing element is biased to the closed position, the coolant flows through the supply valve to the needle probe. The movable sealing element is coupled to a bracket element that is 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, wherein 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, a movable sealing element; a biasing element configured to apply the biasing force to the movable sealing element toward the coolant path, the biasing element being a spring element, a biasing element; comprising; The cryogenic device, wherein the supply valve is disposed along the coolant path between the opening of the auxiliary path and the needle probe. **Claim 16** The cryogenic device according to claim 15, wherein the user-actuable element is a button. **Claim 17** The cryogenic device according to claim 16, wherein the button includes a mechanical or virtual button.

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