Directional Cryoablation System

Abstract

A cryoablation system capable of assuming a directionally active state and including a cryoablation probe and a controller is provided. [Solution] The cryoablation probe has an active area including a cooling chamber and a heating chamber facing the cooling chamber, the cooling chamber and the heating chamber being insulated from each other to minimize energy loss between them, thereby selectively and directionally forming ice at a target site. The cooling chamber can include a temperature sensor and an exhaust tube passing through the probe to direct a fluid or gas exhibiting a Joule-Thomson cooling effect. The heating chamber can include a temperature sensor and a heating core having a heating zone. A controller of the cryoablation system processes temperature measurement data from the sensors in the heating chamber and the cooling chamber, and adjusts the heating zone based on the processed temperature measurement data to maintain a sufficiently constant temperature, thereby mitigating or preventing ice formation on the heating chamber.

Description

Related Applications

[0001] This application claims priority to U.S. Patent Application No. 17 / 979,963, entitled "Directional Cryoablation System," filed November 3, 2022, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] FIELD OF THE INVENTION This application relates generally to directional cryoablation systems. [Background technology]

[0003] Cryoablation is a procedure that uses liquids or gases to freeze and destroy abnormal tissue. Cryoneurolysis involves intentionally freezing nerves to induce reversible ablation and reduce subsequent nerve regeneration. Recently, the combination of cryoneurolysis with imaging (e.g., computed tomography scans, fluoroscopy, ultrasound, etc.) guidance has enabled numerous systemic nerve targets for pain management, such as minimally invasive procedures that do not require opioid drugs or high-risk surgery. Currently, workers interested in cryoneurolysis use tumor cryoablation probes, which are small (less than approximately 2.4 millimeters (mm)) diameter metal needles with symmetrically positioned internal members and linear energy flow through the needle to maximize the area of ​​ablated tissue. These needle-like probes are designed to destroy tumor cells and require temperatures below approximately -40°C. The probe is inserted into the tumor, and pressurized gas (e.g., argon gas) can be passed through the needle. As the argon gas expands, the surrounding volume cools (the Joule-Thomson (JT) effect), resulting in an elliptical ablation zone where the tumor is engulfed in ice at approximately -140°C. The airflow is turned on and off to induce an osmotic gradient shift that leads to cell lysis and tumor rupture. This effect is highly reliable in tumor cryoablation because the probe is inserted into the tissue and the lesion is non-discrete and widespread.

[0004] Unlike cryoablation, this method does not allow for the insertion of a probe into the nerve, as this could cause unnecessary mechanical damage and pain. Furthermore, the temperature suitable for inducing ice crystallite formation within the nerve membrane is approximately -20°C, and the procedure typically lasts for at least 10 minutes. When performing cryoablation, the probe is typically placed parallel to the target nerve, which poses various challenges to the use of conventional probes, including non-target injury, inaccurate inclusion of the target nerve in the ablation zone, and unpredictable and unknown internal target tissue temperatures. This can lead to serious adverse consequences, including postoperative pain, organ damage, and even death.

[0005] The success of cryoablation surgery is closely related to exposing the target nerve to the correct amount of cooling temperature for the correct duration. If the temperature is too low and the duration too long, irreversible nerve ablation can occur, potentially resulting in permanent nerve loss. If the temperature is insufficiently low and the duration too short, partial ablation can occur, resulting in reduced or no therapeutic effect.

[0006] Currently, to measure target tissue temperature during an ablation procedure, operators typically insert a second probe near the target tissue. However, inserting such a second probe can be challenging due to the difficulty of correctly positioning the second probe, increased procedure time, and increased risk of patient injury. Alternatives to inserting a second probe involve calculations based on gel-like hot wire data or core probe temperature from bench tests. These methods assume ideal conditions and have been shown to differ from the actual temperature obtained on the patient. Therefore, it is necessary to obtain actual target tissue temperature measurements when performing a cryoablation procedure.

[0007] Additionally, a key obstacle to achieving the required cryoexposure is accounting for differences in body mass index and composition among patients. The greater the body mass index, the greater the thermal load placed on the device within the patient. This leads to unpredictable and variable ablation zones and treatment outcomes. Therefore, when performing cryoablation procedures, it is necessary to control the temperature of the ablation zone.

[0008] The goal of cryoneurolysis is to simultaneously ablate the target nerve while sparing surrounding structures. This is difficult to achieve with current tumor ablation devices, which create a large, oval-shaped frozen zone (e.g., an area of ​​ice) that ablates all nearby target (e.g., nerve) and non-target (e.g., organ, bone, muscle) structures. Damage to non-target structures is common and has been shown to result in additional postoperative pain and even death. Protective techniques such as water isolation, carbon dioxide pneumoperitoneum isolation, and balloon spacer techniques can be used. In particular, current clinical practice to reduce non-target damage involves injecting air or saline into the area to distance non-target structures from the target tissue. However, these methods are cumbersome and require continuous monitoring and repositioning due to diffusion of the injected gas or fluid. Furthermore, significant probe movement requires reimaging to assess probe position. All of these techniques increase surgical time, radiation exposure, and can affect probe performance. Therefore, alternatives are needed to avoid non-target damage when performing cryoablation procedures. Summary of the Invention

[0009] The present invention provides a cryoablation system capable of exhibiting a directionally active state and a non-directionally active state. The cryoablation system may include a cryoablation probe (also referred to herein as a "probe") and a controller. The cryoablation probe is positioned at an ablation target site and may include a shaft. The shaft may have an outer surface, an inner surface, a distal portion, a proximal portion, a first side, and a second side opposite the first side. The probe may include an active area located at the distal portion of the shaft. The active area may include a cooling chamber located on the first side of the shaft and a heating chamber located on the second side of the shaft. The cooling chamber and the heating chamber are insulated from each other to minimize energy loss therebetween, thereby selectively forming ice at the target site during the directionally active state of the cryoablation system. The cooling chamber may include an exhaust pipe with a capillary installed therein, and the exhaust pipe is configured to direct a fluid or gas exhibiting a Joule-Thomson cooling effect through the shaft. The heat exchanger coil can be located above the capillary. The cooling chamber can further include at least one temperature sensor located adjacent to the exhaust pipe. The heating chamber can include a heating plate, at least one temperature sensor located adjacent to the heating plate, and a heating core located between the exhaust pipe and the heating plate. The heating core can include a heating zone. The cryoablation system can further include a controller operably connected to the cryoablation probe. The controller can include a processor and a memory.The memory can have computer-executable instructions stored therein that, when executed by the processor, cause the controller to process temperature measurement data from at least one sensor in the heating chamber and at least one sensor in the cooling chamber, and adjust a heating area of ​​the heating core based on the processing of the temperature measurement data to maintain a sufficiently constant temperature to mitigate or prevent ice formation in the heating chamber during a directional active state of the cryoablation system. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view of a cryoablation probe according to one aspect of the present disclosure. [Figure 2] FIG. 1 is a side view of an active area of ​​a cryoablation probe according to one aspect of the present disclosure. [Figure 3] FIG. 1 is a perspective view of an active area of ​​a cryoablation probe according to one aspect of the present disclosure, showing the internal components of the active area of ​​the cryoablation probe. [Figure 4] FIG. 1 is a cross-sectional view of an active area of ​​a cryoablation probe according to one aspect of the present disclosure. [Figure 5] FIG. 1 is a top view of a cryoablation probe according to one aspect of the present disclosure, showing a window in the cooling chamber of the cryoablation probe. [Figure 6] FIG. 1 is a perspective view of an active area of ​​a cryoablation probe according to one aspect of the present disclosure, showing the internal components of the working area of ​​the cryoablation probe. [Figure 7] FIG. 1 is a plan view of a heating core of a heating chamber of a cryoablation probe according to one aspect of the present disclosure. [Figure 8] FIG. 1 is a side view of a heating chamber of a cryoablation probe according to one aspect of the present disclosure. [Figure 9] FIG. 9 is an enlarged view of the thermocouple wires proximal to the heating chamber of FIG. 8. [Figure 10] FIG. 9 is an enlarged view of the distal thermocouple wires of the heating chamber of FIG. 8. [Figure 11] FIG. 1 is a block diagram illustrating exemplary components of a controller of a cryoablation system according to one aspect of the present disclosure. [Figure 12] FIG. 10 is a schematic diagram of directional ice formation after activating the cryoablation probe. [Figure 13] FIG. 10 is a schematic illustration of circumferential ice formation after activating the cryoablation probe. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure relates to cryoablation probes and cryoablation systems, including cryoneural lysis probes and systems. When used with respect to elements described herein, unless otherwise specified, the terms "one" and "the" refer to at least one or more of the elements, including combinations thereof. Also, unless otherwise specified, the terms "or" and "and" refer to "and / or" and combinations thereof. "Essentially" refers to the distance, shape, or arrangement of the elements, not necessarily the mathematically exact distance, shape, or arrangement of the elements, but rather a distance, shape, or arrangement that one skilled in the art would recognize as typically or approximately having the distance, shape, or arrangement of the elements. Thus, "essentially" refers to the perfect or nearly perfect degree of a characteristic, property, state, or structure. A precise degree of tolerance from a characteristic, property, state, or structure will have the same overall result as if the absolute characteristic, property, state, or structure were obtained. Unless otherwise specified, the terms "first," "second," etc., are used to distinguish one element from another, not quantitatively. Therefore, a "first" element described below may also be referred to as a "second" element. Elements "connected to," "operably connected to," "located adjacent to," "located between," "located on," or "located at" other elements may have intervening elements therebetween, so long as the cryoablation system can perform its intended purpose. Unless otherwise specified, the order of operations (or steps) is not limited to the order shown in the claims or drawings. As used herein, a "patient" includes mammals, such as humans. While the drawings show combinations of several elements of a cryoablation system and a cryoablation probe, it should be noted that such elements may be included in other examples or aspects shown in other drawings. In other words, each disclosed aspect and example of the present disclosure may be considered alone or in combination with other aspects and embodiments of the present disclosure.

[0012] The present disclosure provides a cryoablation system that can be used to freeze and destroy diseased tissue, including nerve ablation. For example, the cryoablation system solves important challenges related to monitoring the temperature of the ablation zone and minimizing non-target damage. In particular, a cryoablation system as disclosed herein can provide measurement of the actual target tissue temperature from the cryoablation probe itself, control the temperature and duration of delivered cold energy without requiring the insertion of a second needle, control the temperature of the ablation zone using an integrated tissue temperature measurement system and real-time temperature-based feedback, create directional freezing zones without affecting surrounding tissue, create specific ablation zone shapes and sizes for various indications regardless of ablation energy mode, prevent or mitigate bridging, and / or control the rate and flow of energy to maximize energy transfer into the target tissue and minimize non-target damage. Note that "bridging" typically refers to bridging through the tissue or bridging through the probe. Bridging through the tissue occurs when ice forming from both edges of the cooling chamber extends into the tissue and connects with each other, positioning the ice radially outward from the heater cell. This results in ice wrapping around the heating chamber (but not necessarily on the heating chamber). Temperature measurements detected by the heating chamber sensor (discussed below) can have a characteristic curve that can be used to detect bridging. For example, a gradual decrease in temperature from the sensor can indicate tissue-based bridging and trigger a process in which the cooling chamber's cooling energy inhibits the heating core and restores directional ice near the cooling chamber. Probe-based bridging occurs when the cooling chamber inhibits the heating core and conducts cooling energy through the outer surface of the probe, directly forming ice on the probe surface. Temperature measurements by the heating chamber sensor (discussed below) can have a characteristic curve that can be used to detect bridging.For example, if the sensor indicates a sudden drop in temperature, this indicates that bridging is occurring through the probe and can trigger a process in which the cooling energy from the cooling chamber inhibits the heating core and restores directional ice.

[0013] Generally, a cryoablation system may include a handle that an operator can grasp to manipulate the cryoablation probe; a vacuum tube to prevent freezing of inactive areas of the cryoablation probe; an exhaust tube to circulate a fluid or gas capable of exhibiting a Joule-Thomson cooling effect from the cryoablation probe; an electromagnetic sensor located within the cryoablation probe to track the position of the cryoablation probe; a copper coil array as a heat exchanger to increase the cooling power of the cryoablation probe; a heating core and heating plate to generate and supply heat to generate a directional thermal gradient; thermocouples or other thermal sensors to measure temperature at specific points to ensure a successful directional ablation zone; a gas connector to flow pressurized gas through the cryoablation probe; and an electrical connector to mate the cryoablation probe to a console electronic device and to program and identify the probe placement.

[0014] With particular reference to FIGS. 1 and 2, the cryoablation system 10 may include a probe 12, a handle 14, a connector 16, and a controller (not shown). The probe 12 may include a shaft 18 having a distal portion 20, a proximal portion 22, a first side 24, and a second side 26 opposite the first side 24. The probe may be a needle having a diameter of about 1.5 mm to about 3.5 mm. Other diameters may also be used. The distal portion 20 may include an active region 28 that, when activated, can generate a frozen zone in the patient's tissue. The active region may include a combined heating and cooling chamber that can generate a directional and positionable frozen zone (e.g., a cryoablation temperature on one side of the probe and a temperature near body temperature on the other side). With particular reference to FIGS. 2 and 3, the active region 28 may include a cooling chamber 30 located on the first side 24 of the shaft 18 and a heating chamber 32 located on the second side 26. With further reference to FIG. 12 , in a directional active state of the cryoablation system, ice forms at or near the first side 24 of the active region 28 of the shaft 18 (e.g., frozen zone 25), but not at or near the second side 26 of the active region 28 of the shaft 18. The directional frozen zone may extend laterally from about 1.5 cm to about 2.0 cm from the center of the probe. These values ​​are exemplary only, and the directional frozen zone may extend to other distances. With reference to FIG. 13 , in a non-directional active state of the cryoablation system, the heating chamber is not activated, and ice 27 formation is not limited to or near the first side 24 of the active region 28 of the shaft 18, but may also form circumferentially, for example, at or near the active region of the probe. With reference to FIGS. 3 and 4 , the cooling chamber 30 and the heating chamber 32 may be separated by a distance D. The heating and cooling chambers are insulated from each other to minimize energy loss therebetween, and ice is selectively formed at the target site during the directional active state of the cryoablation system. The heating chamber may be disposed radially outwardly extending from a central axis CA passing through the shaft.The cooling and heating chambers can be insulated from one another to minimize energy loss, thereby allowing ice to form less than 360° around the cryoablation probe during a directional active state of the cryoablation system.

[0015] Referring to FIG. 3, the cooling chamber 30 may include an exhaust tube 34 positioned to direct a fluid or gas exhibiting Joule-Thomson cooling to the shaft 18. The fluid or gas may be any suitable fluid or gas capable of exhibiting Joule-Thomson cooling, such as argon, nitrogen, or oxygen. The exhaust tube may have a closed distal end to contain all airflow within the exhaust tube. Referring specifically to FIG. 6, an open-ended capillary 44 may be installed inside the exhaust tube 34. A heat exchanger coil may be installed above the capillary tube. Pressurized cryogenic gas or fluid may flow from the console (connected to a cryogenic gas or fluid source) and enter the probe shaft through the capillary 44. As the gas or fluid leaves the capillary, it expands, and the pressure of the gas or fluid decreases. The gas or fluid then returns to the console through the inner chamber of the exhaust tube and is exhausted to the ambient environment. This pressure drop results in a change in kinetic energy and is explained by the Joule-Thomson effect. As the gas expands, the pressure of the gas or fluid decreases, causing the temperature of the surrounding area (inside and outside the probe) to drop rapidly. This cooling causes water in nearby tissue to freeze, resulting in icing.

[0016] Referring to Figures 2, 4, and 5, the shaft on a first side of the cryoablation probe's active area can define an opening window 38 and an exhaust tube 34 positioned within the opening window 38. This allows the exhaust tube to be directly exposed to the target tissue site. The window can encircle the active area of ​​the cryoablation probe shaft and extend less than 180° to control and limit the "extent" of freezing. As shown in Figures 3, 4, and 6, the exhaust tube 34 can include a basic elliptical cross-sectional shape. When coupled with a copper coil 42, the elliptical exhaust tube 34 can reduce the diameter of the exhaust lumen 40, allowing sufficient contact between the copper coil 42 (which serves as a heat exchanger to increase the cooling power of the cooling chamber) and the capillary 44 and exhaust tube 34 for fluid or gas heat transfer. Additionally, the elliptical exhaust tube can provide sufficient space for sensors (described below) positioned on the surface of the exhaust tube. The exhaust tube may have other shapes.

[0017] Returning to FIG. 3 , the heating chamber 32 can include a heating plate 46 and a heating core 48. The heating core 48 can be located between the exhaust pipe 34 and the heating plate 46. The heating core can include heating zones. Referring to FIG. 7 , the heating core 48 can include at least two independently controlled heating zones 50 and 52, each capable of generating a specific amount of thermal energy to reduce or prevent ice formation in or around the heating chamber. The heating zone 50 can be located in a distal portion of the heating core, and the heating zone 52 can be located in a proximal portion of the heating core. Preferably, the two or more zones are positioned adjacent to each other longitudinally so that there is no or minimal space of “unheated” heating core. At least two zones are necessary due to the different temperature gradients along the longitudinal axis of the probe created by the Joule-Thomson effect. This allows the heating chamber to apply a minimal amount of heat to prevent bridging while not interrupting the probe regeneration cycle by heating the exhaust gas or fluid. Optionally, the heating core can include a single heating zone with traces of variable width, thereby creating a two-zone effect. That is, the heater traces can be arranged to have smaller / larger widths to create an effect similar to that of a two-zone effect. Smaller / thinner traces result in more heating. Wider / thicker traces result in less heating. This allows the trace width / thickness to be modulated to emulate a variable resistance and create variable heating in a single zone.

[0018] The heating core can have a basic concave configuration. A concave configuration is one in which a circular needle is used to position the heater as far away from the exhaust pipe as possible. The heating core may have other configurations. The heating plate can provide a rigid, smooth, and non-invasive outer surface for the heating core and sensors (described below). It can also function as a heat sink to equalize the temperature of at least two independently controlled zones. For example, the heating plate can be made of stainless steel. Other materials are also possible. The heating core can include constantan laminated between polyamide sheets, although other materials are also possible.

[0019] The insulation can separate the heating chamber and the cooling chamber and minimize the amount of cooling energy that can flow through the heating chamber. The insulation can bias the cooling gradient toward the first side of the probe's active area and maximize ice deposition at the target tissue site. With particular reference to FIG. 4 , in certain embodiments, a layer 66 of high thermal conductivity, low electrical conductivity material can be provided between the heating core 48 and the heating plate 46 (e.g., laminated to the inner surface of the heating plate), and a layer 68 of low thermal conductivity, low electrical conductivity material can be provided between the heating core 48 and the exhaust pipe 34 (e.g., laminated to the inner surface of the heating plate). The material can be an epoxy resin material for adhering to the components. As described above, by adhering the high thermal conductivity, low electrical conductivity material provided between the heating core and the heating plate to the heating plate, the thermal gradient of the heating core can be biased toward the outside of the heating plate and heat flow from the heating chamber to the cooling chamber can be minimized. That is, such a material with high thermal conductivity and low electrical conductivity can maximize the heating gradient toward the outside of the tissue, thereby minimizing the adverse effect of the heating core on freezing. Excessive heat from the heating core to the exhaust duct can adversely affect the size of the target ablation zone. Such a material with high thermal conductivity and low electrical conductivity can also ensure sufficient heating of the heating chamber to prevent or mitigate freezing or thermal energy transfer within the heating chamber. A layer of a material with low thermal conductivity and low electrical conductivity placed between the heating core and the exhaust duct can limit the transfer of heat / cold gradients within the probe. Such a material can fill the space between the heating core and the exhaust duct. Such a material promotes directional freezing (i.e., freezing) between the heating chamber and the cooling chamber. Without such a material, the cooling power of the cooling chamber could inhibit the heating core, preventing directional freezing. The heating chamber needs to heat up when clinically necessary, but not become unsafe, and low thermal conductivity and electrical conductivity materials help ensure this characteristic.

[0020] 3 and 8-10, the cooling chamber 30 includes at least one temperature sensor, for example, a proximal temperature sensor. The cooling chamber may optionally include at least two temperature sensors 54a and 54b disposed near the exhaust pipe 34. The heating chamber may include at least one temperature sensor, for example, a proximal temperature sensor. The heating chamber 32 may optionally include at least two temperature sensors 56a and 56b, which may be disposed adjacent to the heating plate 46. The at least two temperature sensors 54a and 54b of the cooling chamber 30 may be located at a proximal portion 58 and a distal portion 60 of the cooling chamber 30, respectively, and the at least two temperature sensors 56a and 56b of the heating chamber 32 may be located at a proximal portion 62 and a distal portion 64 of the heating chamber 32, respectively. As shown in FIGS. 9 and 10, the temperature sensors may be thermocouple wires. In particular, for the cooling chamber, a distal sensor may be installed on the exterior of the exhaust pipe and may measure the temperature between the cooling chamber and the heating chamber, proximate the capillary opening. This temperature can be used to verify whether maximum performance has been achieved by detecting the temperature cooling rate and to adjust heating and cooling to achieve the formation of a directional freezing zone. A proximal sensor may be installed on the exterior of the exhaust pipe between the cooling chamber and the heating chamber and may be used to measure the temperature near the edge of the target ablation site before gas is exhausted from the active region of the probe. This temperature measurement can also be used to verify whether maximum performance has been achieved by detecting the temperature cooling rate and to adjust heating and cooling to achieve the formation of a directional freezing zone. For the heating chamber, a distal sensor may be installed between the heating plate and the heating core within the epoxy resin layer. This distal sensor may be used to measure the temperature of the distal portion of the heating chamber. Trends in the heating curve may be used to detect ice formation (i.e., bridging) outside the target ablation site and adjust the heating power to ensure heating at a safe temperature.The proximal sensor can be used to measure the temperature of the proximal portion of the heating chamber and can be used to monitor trends in the heating curve to detect ice formation (i.e., bridging) outside the target ablation site and adjust the heating power to ensure heating at a safe temperature.

[0021] The cryoablation system can further include an inactive region of the cryoablation probe distal to the heating core, the cryoablation probe including an insulating sleeve positioned to prevent or minimize icing around the inactive region of the cryoablation probe. A portion of the exhaust tube proximate the active region can be provided in the insulating sleeve.

[0022] Referring to FIG. 11 , the cryoablation system can include a controller 70 operably connected to the cryoablation probe and including a processor 72 and a memory 74. The memory 74 can have computer-executable commands 76 stored therein, which, when executed by the processor 72, cause the controller 70 to process temperature measurement data from at least one sensor in the heating chamber and at least one sensor in the cooling chamber. The commands can also cause the controller 70 to adjust the heating zones of the heating core (or at least two independently controlled zones 50, 52 of the heating core 48 in some embodiments) based on the processing of the temperature measurement data to maintain a sufficiently constant temperature to mitigate or prevent ice formation in the heating chamber during a directionally active state of the cryoablation system. In particular, the heating core can be controlled by the controller to maintain a constant temperature on the probe surface. Thermocouples or other thermal sensors can be strategically positioned, and the controller receiving temperature measurement data from the sensors can prevent bridging and ensure the probe does not overheat, resulting in unintended tissue burns. An embodiment with at least two zones of heating cores regulated by a controller is advantageous because the cooling energy creates an energy gradient along the axis of the probe, typically being colder at the distal end. The distal heating core typically consumes twice as much power as the proximal heating core. At least two heating zones also allow the controller to regulate the minimum amount of heat input to prevent bridging, thereby reducing interference with the cryo-cooling cycle.

[0023] The controller may be a proportional-integral-derivative (PID) controller. A sensor may be used to determine and communicate tissue temperature measurements in real time to the PID controller. The PID controller may adjust the gas / fluid flow duty ratio and heating array temperature to achieve the desired freezing zone shape, size, and temperature. In particular, supplemental or alternative to the above commands, the controller may have computer-executable commands stored in memory that, when executed by the processor, cause the controller to perform other steps. For example, such commands may include processing based on temperature measurement data to monitor ice bridging around or on the cryoablation probe; processing based on temperature measurement data to determine when gas or fluid is transported from the exhaust pipe and processing based on temperature measurement data to determine when to heat the heating chamber; processing based on temperature measurement data to stop heating the heating chamber or fluid or gas when a critical value is reached; monitoring the cooling rate of the cooling chamber and adjusting the cooling rate based on temperature measurement data obtained from proximal and distal temperature sensors of the cooling chamber; monitoring the heating rate of the heating chamber and adjusting the heating rate based on temperature measurement data obtained from proximal and distal temperature sensors of the heating chamber; adjusting the flow rate of fluid or gas through the exhaust pipe based on processing of the temperature measurement data; adjusting the power level of the heating chamber (e.g., including each heating zone of at least two independently controlled zones of the heating core) based on processing of the temperature measurement data, and combinations thereof.

[0024] The memory 74 may contain computer-readable commands that, when executed by the processor 72, cause the controller to perform various functions ascribed to the controller throughout this disclosure. The computer-readable commands may be coded within the memory 74. The memory may include non-transitory computer-readable storage media, including any volatile, non-volatile, magnetic, optical, or dielectric, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital medium, the only exception being a transitory, propagating signal.

[0025] A non-limiting example of a proposed technique for generating directional ice may include delivering gas or fluid for two minutes when adjusting heater power using temperature sensor measurements. In particular, the amount of time the gas or fluid is delivered may be determined by a curve of the temperature sensor measurement data. The protocol may include stopping the delivery of gas or fluid for 30 seconds when the curve of the temperature sensor measurement data reduces the power of the heating core. For example, this cycle may be repeated five times to generate ice of a desired size. Such a protocol is exemplary only, and other protocols may be used to generate frozen zones of a desired size, shape, and configuration.

[0026] The cryoablation system may include other components, such as a console. The console may provide many different functions. For example, it may regulate gas pressure and flow, power the probes and electronic devices within the console, and house probe position tracking circuitry, a computer, and a touch panel monitor. The console may provide immediate power to and control multiple cryoablation probes. Argon gas, or other fluids or gases that exhibit Joule-Thomson cooling effects, may be attached to the console inlet port, flow through regulators and dryers, and exit the console by controlling the gas flow through the probe gate valve. Power means may be arranged to provide sufficient power to all electronic devices inserted within the cryoablation probes. A microcontroller may monitor the compliance and safety of the entire system.

[0027] Compared with thermal therapies such as radiofrequency, microwave, laser, or ultrasound, the focused cryoablation system is highly suitable for pain management, as it reduces postoperative pain and neuroma formation. The system can be used to treat a variety of pain conditions, such as chronic abdominal pain (e.g., the target nerve may be a splanchnic nerve connected to the celiac plexus), phantom limb pain, pudendal neuralgia, and groin pain. Other conditions include chronic diseases caused by abnormal neural activity, such as sexual dysfunction, tachycardia, diabetes, and obesity.

[0028] Each disclosed aspect and embodiment of the present disclosure may be considered alone or in combination with other aspects, embodiments, and variations of the present disclosure. Also, some features of the embodiments and embodiments of the present disclosure may be shown only in some drawings or described in some parts of the disclosure in other ways, but these features may be combined with other embodiments and embodiments shown in other drawings or other parts of the disclosure. Similarly, some features of the embodiments and embodiments of the present disclosure shown in some drawings or described in some parts of the disclosure in other ways may be optional or may be omitted from these embodiments and embodiments. Furthermore, when describing a range, all points within that range are included in the present disclosure. Furthermore, unless otherwise specified, none of the steps of the methods of the present disclosure are limited to any particular order of execution. Furthermore, all references cited herein are incorporated by reference in their entirety.

Claims

1. 1. A cryoablation system having a directionally active state and a non-directionally active state, the cryoablation system including a cryoablation probe and a controller, the cryoablation probe being adapted to ablate a target site; the cryoablation probe includes a shaft and an active region; the shaft having an outer surface, an inner surface, a distal portion, a proximal portion, a first side, and a second side, the first side opposing the second side; the active area is located at the distal portion of the shaft, and the active area includes a cooling chamber located on the first side of the shaft and a heating chamber located on the second side, the cooling chamber and the heating chamber being insulated from each other to minimize energy loss between the cooling chamber and the heating chamber, such that ice is selectively formed at the target site during a directional active state of the cryoablation system; the cooling chamber includes an exhaust pipe, a heat exchanger coil, and at least one temperature sensor; the exhaust pipe includes a capillary disposed inside the exhaust pipe, and the exhaust pipe is configured to conduct a fluid or gas exhibiting a Joule-Thomson cooling effect through the shaft; the heat exchanger coil is located above the capillary; the at least one temperature sensor in the cooling chamber is located adjacent to the exhaust pipe; the heating chamber includes a heating plate, at least one temperature sensor, and a heating core; the at least one temperature sensor in the heating chamber is located adjacent to the heating plate; the heating core is located between the exhaust pipe and the heating plate and includes a heating zone; The controller is operably connected to the cryoablation probe, the controller including a processor and a memory, the memory having computer-executable instructions stored therein, the computer-executable instructions, when executed by the processor, processing temperature measurement data from at least one temperature sensor in the heating chamber and at least one temperature sensor in the cooling chamber; and adjusting the heating zones of the heating core to maintain a sufficiently constant temperature based on processing of temperature measurement data, thereby mitigating or preventing ice formation in the heating chamber during a directional active state of the cryoablation system.

2. 10. The cryoablation system of claim 1, wherein the heating zones include at least two independently controlled heating zones, and wherein adjusting the heating zones includes adjusting the at least two independently controlled heating zones.

3. 10. The cryoablation system of claim 1, wherein the heating zones include a single heating zone having a variable resistance, and adjusting the heating zones includes adjusting the single heating zone having a variable resistance.

4. the at least one temperature sensor in the heating chamber includes at least two temperature sensors; the at least one temperature sensor in the cooling chamber includes at least two temperature sensors; 10. The cryoablation system of claim 1, wherein processing the temperature measurement data comprises processing temperature measurement data from at least two sensors in the heating chamber and temperature measurement data from at least two sensors in the cooling chamber.

5. the at least two temperature sensors in the heating chamber include a proximal temperature sensor located in a proximal portion of the heating chamber and a distal temperature sensor located in a distal portion of the heating chamber; 5. The cryoablation system of claim 4, wherein the at least two temperature sensors in the cooling chamber include a proximal temperature sensor located in a proximal portion of the cooling chamber and a distal temperature sensor located in a distal portion of the cooling chamber.

6. 10. The cryoablation system of claim 1, wherein the at least one temperature sensor in the heating chamber and the at least one temperature sensor in the cooling chamber are thermocouples.

7. 10. The cryoablation system of claim 1, wherein the cooling chamber and the heating chamber are insulated from each other such that, in a directionally active state of the cryoablation system, less than 360° of ice forms around the cryoablation probe.

8. 10. The cryoablation system of claim 1, further comprising: a layer of material with high thermal conductivity and low electrical conductivity disposed between the heating core and the heating plate; and a layer of material with low thermal conductivity and low electrical conductivity disposed between the heating core and the exhaust pipe.

9. 9. The cryoablation system of claim 8, wherein the material with high thermal conductivity and low electrical conductivity is epoxy resin, and the material with low thermal conductivity and low electrical conductivity is epoxy resin.

10. 10. The cryoablation system of claim 1, wherein the cooling chamber and the heating chamber are insulated from each other such that cryoablation temperatures occur only on the first side of the cryoablation probe when the cryoablation system is in a directionally active state.

11. 2. The cryoablation system of claim 1, wherein the shaft of the cryoablation probe has an opening window disposed therein, and the exhaust pipe is disposed within the opening window.

12. 10. The cryoablation system of claim 1, wherein a central longitudinal axis extends through the shaft of the cryoablation probe, and wherein the heating core is disposed radially outward from the central longitudinal axis.

13. 10. The cryoablation system of claim 1, wherein the heating chamber and the cooling chamber are also sized and positioned to generate circumferentially formed ice at the target site when the cryoablation system is in a non-directionally active state.

14. 10. The cryoablation system of claim 1, further comprising computer-executable commands stored in the memory, the computer-executable commands, when executed by the processor, causing the controller to monitor ice bridging around or on the cryoablation probe based on processing of the temperature measurement data.

15. The cryoablation system further includes computer-executable instructions stored in the memory, the computer-executable commands, when executed by the processor, to: determining the timing of directing a fluid or gas through the exhaust line based on processing the temperature measurement data; and determining timing to heat the heating chamber based on processing of the temperature measurement data.

16. 10. The cryoablation system of claim 1, further comprising computer-executable commands stored in the memory, which when executed by the processor cause the controller to stop heating the heating chamber, or heating the fluid, or heating the gas when a threshold is reached based on processing of the temperature measurement data.

17. The cryoablation system further includes computer-executable instructions stored in the memory, the computer-executable commands, when executed by the processor, to: monitoring a cooling rate of the cooling chamber and adjusting the cooling rate based on temperature measurement data obtained from proximal and distal temperature sensors of the cooling chamber; 6. The cryoablation system of claim 5, wherein the controller monitors a heating rate of the heating chamber and adjusts the heating rate based on temperature measurement data obtained from proximal and distal temperature sensors of the heating chamber.

18. 10. The cryoablation system of claim 1, further comprising computer-executable commands stored in the memory, the computer-executable commands, when executed by the processor, causing the controller to adjust the flow rate of the fluid or gas through the exhaust line based on processing of the temperature measurement data.

19. 10. The cryoablation system of claim 1, further comprising computer-executable commands stored in the memory, the computer-executable commands, when executed by the processor, causing the controller to adjust a power level of the heating chamber based on processing of the temperature measurement data.

20. 10. The cryoablation system of claim 1, further comprising a handle located at a proximal end of a proximal portion of the shaft, the handle including at least one electromagnetic sensor, the at least one electromagnetic sensor of the handle positioned to track a position of the cryoablation probe.

Images