Starting method of cryoablation system

Abstract

The present application provides a starting method for a cryoablation system. The cryoablation system includes a cryoablation device, a first, a second, and a third pressure vessel. The first pressure vessel is used to store a liquid working medium and is connected to the cryoablation device through a first pipeline; the second pressure vessel is used to store a gaseous working medium; the third pressure vessel is arranged inside the first pressure vessel and is used to transform the liquid working medium into a gaseous working medium. The starting method includes pre-cooling the first pipeline and the cryoablation device with the liquid working medium in the first pressure vessel, and the second pressure vessel recovering the working medium in the first pipeline and the cryoablation device; after pre-cooling, the third pressure vessel outputs a gaseous working medium to the second pressure vessel and, via the second pressure vessel, to the first pressure vessel, and adjusting the pressures of the two vessels to build pressure; after building pressure, the gaseous working medium in the second pressure vessel displaces the inside of the cryoablation device; after displacement, the second pressure vessel outputs a liquid working medium to the cryoablation device to start cryoablation. The efficiency is improved.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to a method for starting a cryoablation system. Background Art

[0002] In the process of combating cancer, chemotherapy, radiotherapy, and surgical treatment have become the three major conventional methods for treating malignant tumors, and tumor immunotherapy is also under intense research. Minimally invasive tumor treatment is an important supplement to surgical treatment. Among various treatment methods for tumors, physical ablation is being increasingly applied, including microwave, cryo, laser, radiofrequency, high-power focused ultrasound, etc., to cause necrosis of cancer tissue.

[0003] In the early 20th century, with the rapid development of industry and technology, refrigerants such as concentrated oxygen, liquid oxygen, concentrated nitrogen, liquid nitrogen, and dry ice were successfully produced in the progress of industrial technology. This not only accelerated the pace of commercial development but also opened up a new world for medical refrigeration and promoted the application of cryogenic technology in medicine. Various different refrigeration technologies have emerged in the continuous progress of cryogenic science, and gas throttling technology, phase change cooling, vapor pressure absorption refrigeration, and thermoelectric refrigeration are the main refrigeration solutions used in modern medicine.

[0004] Existing cryoablation systems have problems such as low rewarming efficiency and high working fluid consumption during the cryoablation process. Summary of the Invention

[0005] This application discloses a method for starting a cryoablation system, which can improve the cryoablation efficiency and reduce the working fluid consumption.

[0006] A method for starting a cryoablation system according to this application, the cryoablation system includes:

[0007] A cryoablation device;

[0008] A first pressure vessel for storing a liquid working fluid and connected to the cryoablation device through a first pipeline;

[0009] A second pressure vessel for storing a gaseous working fluid;

[0010] A third pressure vessel disposed within the first pressure vessel for converting the liquid working fluid into a gaseous working fluid;

[0011] The starting method includes:

[0012] Pre-cooling the first pipeline and the cryoablation device with the liquid working fluid in the first pressure vessel, and simultaneously recovering the refluxing working fluid in the first pipeline and the cryoablation device using the second pressure vessel;

[0013] After precooling, use the third pressure vessel to output gaseous working medium to the second pressure vessel and, via the second pressure vessel, to the first pressure vessel, and adjust the pressures of the first pressure vessel and the second pressure vessel to build pressure;

[0014] After pressure building, use the gaseous working medium in the second pressure vessel to displace the interior of the cryoablation device;

[0015] After displacement, output liquid working medium to the cryoablation device through the second pressure vessel to initiate cryoablation.

[0016] The following also provides several optional methods, which are not additional limitations to the above overall solution, but only further supplements or optimizations. On the premise of no technical or logical contradictions, each optional method can be combined with the above overall solution separately, or multiple optional methods can be combined with each other.

[0017] Optionally, the first pipeline has a double-layer structure inside and outside. When meeting the first preset condition, the liquid working medium outputs two paths through the inner layer of the first pipeline. The first path passes through the cryoablation device until the second pressure vessel, and the second path passes through the outer layer of the first pipeline until the second pressure vessel;

[0018] When meeting the second preset condition, the precooling ends and the output of the first pipeline stops.

[0019] Optionally, the first preset condition is that the current liquid level of the first pressure vessel is within a preset range.

[0020] Optionally, the second preset condition is that the first current temperature of the inner layer of the first pipeline is within a preset range.

[0021] Optionally, during the precooling process, use a booster pump to increase the second current pressure of the second pressure vessel to be within a second preset pressure range, and the booster pump is delayed to close after the precooling ends.

[0022] Optionally, after precooling, obtain the third current pressure and the third current liquid level of the third pressure vessel. If the third current pressure is lower than the first current pressure and the third current liquid level is lower than the first liquid level preset value, the third pressure vessel accepts the liquid working medium.

[0023] Optionally, before the third pressure vessel conveys gaseous working medium to the second pressure vessel, it also includes pre-boosting the third pressure vessel;

[0024] The steps of the pre-boosting include obtaining the third current liquid level and the third current pressure of the third pressure vessel. After the third current liquid level and the third current pressure meet the preset conditions, the third pressure vessel is heated to vaporize the liquid working medium inside itself until the pre-boosting completion condition is met.

[0025] Optionally, after the pre-boosting is completed, the pressure building of the second pressure vessel is started. The condition for the completion of the pressure building of the second pressure vessel is that the second current pressure is within the third pressure preset range.

[0026] Optionally, after the pressure building of the second pressure vessel is completed, the pressure building of the first pressure vessel is carried out. The condition for the completion of the pressure building of the first pressure vessel is that the first current pressure is within the first pressure preset range.

[0027] Optionally, during the replacement process, the reflux working medium is heated and pressurized through a heat exchanger and a booster pump.

[0028] The starting method of the cryoablation system provided by this application displaces the internal air and moisture before cryoablation to improve the subsequent working efficiency, and recovers the working medium during cryoablation to reduce the loss of the working medium. Description of the Drawings

[0029] Figure 1 is a schematic diagram of the principle of the cryoablation system of this application;

[0030] Figure 2 is a schematic diagram of the structure of the liquid refrigerant tube sleeve;

[0031] Figure 3 is a schematic diagram of the structure of the gas-liquid separation device of the liquid refrigerant tube;

[0032] Figure 4 is a schematic diagram of the structure of the liquid refrigerant output valve;

[0033] Figure 5 is a schematic diagram of the structure of the liquid refrigerant tube;

[0034] Figure 6 is a schematic diagram of the structure of the phase change pressure vessel;

[0035] Figure 7A 、 Figure 7B is a schematic diagram of the structures of two embodiments of the one-way flow device for the liquid working medium;

[0036] Figure 8 is a schematic diagram of the structure of the one-way flow device for the liquid working medium;

[0037] Figure 9 is a schematic diagram of the structure of the computer device;

[0038] Figures 10 to 15It is a flowchart of a method. The connection relationships between the figures can be referred to the identifiers corresponding to the boundary parts;

[0039] Figure 16 It is a flowchart of the startup method of a cryoablation system according to an embodiment of the present application. Specific embodiments

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0041] It should be noted that when a component is referred to as being "connected" to another component, it can be directly connected to the other component or there may also be an intermediate component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments, and are not intended to limit this application.

[0043] The present application provides a rewarming control method based on a cryoablation system. The cryoablation system includes:

[0044] A cryoablation device;

[0045] A first pressure vessel for storing a liquid working medium and connected to the cryoablation device through a first pipeline;

[0046] A second pressure vessel for storing a gaseous working medium;

[0047] Cryoablation and rewarming are carried out alternately, and the number of alternations is about 2 to 6 times.

[0048] During the interval of cryoablation, rewarming control is also included, and the rewarming control method includes:

[0049] Shut off the output of the liquid working medium in the first pressure vessel;

[0050] Use the second pressure vessel to output the heated gaseous working medium to the cryoablation device through a sixth pipeline configured with a replacement and rewarming heat exchanger. The rewarming stops when the temperature of the cryoablation device reaches 60 to 80 degrees Celsius.

[0051] Refer to Figure 1, this application provides a rewarming system for cryoablation, including a gaseous working medium pressure vessel (C2) and a replacement and rewarming pipeline (L6). The replacement and rewarming pipeline (L6) is used to connect the gaseous working medium pressure vessel (C2) and the cryoablation device; the replacement and rewarming pipeline (L6) includes:

[0052] A replacement and rewarming pipe (L6-1), one end of which is connected to the gaseous working medium pressure vessel (C2), and the other end is connected to the cryoablation device and can transport the gaseous working medium in the gaseous working medium pressure vessel to the cryoablation device (CP);

[0053] A replacement and rewarming solenoid valve (L6-2), which is arranged on the replacement and rewarming pipe (L6-1) to control the on-off of the replacement and rewarming pipe (L6-1);

[0054] A replacement and rewarming heat exchanger (L6-3), which is used to heat the gaseous working medium in the replacement and rewarming pipe (L6-1);

[0055] A replacement and rewarming check valve (L6-5), which is arranged on the replacement and rewarming pipe (L6-1) to limit backflow.

[0056] Wherein a rewarming temperature sensor (L6-4) is arranged on the downstream side of the replacement and rewarming heat exchanger to correspondingly control the replacement and rewarming heat exchanger (L6-3).

[0057] In one embodiment, the cryoablation system further includes a third pressure vessel arranged in the first pressure vessel for changing the liquid working medium into a gaseous working medium; wherein starting the cryoablation includes:

[0058] Using the liquid working medium in the first pressure vessel to precool the first pipeline and the cryoablation device, and at the same time using the second pressure vessel to recover the working medium flowing back in the first pipeline and the cryoablation device;

[0059] After precooling, using the third pressure vessel to output gaseous working medium to the second pressure vessel and, via the second pressure vessel, to the first pressure vessel, and adjusting the pressures of the first pressure vessel and the second pressure vessel to build pressure;

[0060] After building pressure, using the gaseous working medium in the second pressure vessel to replace the inside of the cryoablation device;

[0061] After replacement, outputting liquid working medium from the first pressure vessel to the cryoablation device to start cryoablation;

[0062] During cryoablation:

[0063] Obtain the first current pressure of the first pressure vessel. If the first current pressure is lower than the first pressure preset value, connect the first pressure vessel and the second pressure vessel, and maintain the pressure in the first pressure vessel within the first working pressure range through the second pressure vessel;

[0064] Obtain the second current pressure of the second pressure vessel. If the second current pressure is lower than the second pressure preset value, connect the second pressure vessel and the third pressure vessel, and maintain the pressure of the second pressure vessel through the gaseous working medium from the third pressure vessel.

[0065] In this embodiment, for the replacement and rewarming pipeline (L6), its replacement and rewarming heat exchanger (L6-3) can heat the fluid working medium passing through the replacement and rewarming pipe (L6-1). The rewarming temperature sensor (L6-4) monitors whether the fluid working medium in the replacement and rewarming pipe (L6-1) reaches the threshold temperature (the fourth current temperature); the opening and closing of the replacement and rewarming solenoid valve (L6-2) controls the fluid working medium in the gaseous working medium pressure vessel (C2) to enter the replacement and rewarming pipe (L6-1); the replacement and rewarming check valve (L6-5) prevents the fluid flowing into the cryoablation device (CP) from flowing back. The replacement and rewarming heat exchanger (L6-3) heats the fluid working medium entering the replacement and rewarming pipe (L6-1) to the rewarming temperature during the rewarming process in the cryoablation procedure; the rewarming temperature > the lower rewarming threshold and the rewarming temperature < the upper rewarming threshold; the temperature detected by the rewarming temperature sensor (L6-4) during the rewarming process in the cryoablation procedure participates in the closed-loop control. By adjusting the heating power of the rewarming heat exchanger (L6-3), the detected rewarming temperature is made to satisfy: the lower rewarming threshold < the rewarming temperature < the upper rewarming threshold; during the replacement process in the cryoablation procedure, the rewarming heat exchanger (L6-3) does not work, and this process does not heat the fluid working medium entering the replacement and rewarming pipe (L6-1). At the same time, a heating component (heatable nickel-chromium wire) is provided at the distal end of the cryoablation device CP (flexible cryoprobe) to cooperate with the rewarming process in the cryoablation procedure.

[0066] There is a pressure sensor C2-1 in the gaseous working medium pressure vessel (C2), and a temperature sensor in the cryoablation device CP to monitor the fifth current temperature of the gaseous working medium in the cryoablation device CP. Calculate the output volume of the rewarming nitrogen gas during rewarming based on the pressure detected by the pressure sensor, calculate the heat output of rewarming by combining the nitrogen gas temperature measured by the temperature sensor, and then control the heating efficiency of the nickel-chromium wire according to the heat output efficiency calculated in real time to make the heat output during rewarming constant. This embodiment adopts a combination of rewarming nitrogen gas and nickel-chromium wire heating. By detecting the temperature and pressure inside the device, the phenomenon of unstable rewarming of the rewarming gas by nickel-chromium wire heating is compensated. Stable and efficient rewarming is achieved, reducing the operation time and improving the operation effect.

[0067] The rewarming system further includes a return air recovery pipeline (L7) and a system flow monitoring and recovery condition control pipeline (L8) that are interconnected. One end of the return air recovery pipeline (L7) is connected to the outlet of the cryoablation device, and one end of the system flow monitoring and recovery condition control pipeline (L8) is connected to the gaseous working medium pressure vessel (C2).

[0068] Among them, the return air recovery pipeline (L7) includes a return air recovery pipe (L7-1). One end of the return air recovery pipe (L7-1) is connected to the outlet of the cryoablation device, and the other end is connected to the system flow monitoring and recovery condition control pipeline (L8). A one-way valve (L7-2) for restricting backflow is provided on the return air recovery pipe (L7-1).

[0069] The system flow monitoring and recovery condition control pipeline (L8) includes a system flow monitoring and recovery condition control pipe (L8-1). One end of the system flow monitoring and recovery condition control pipe (L8-1) is connected to the return air recovery pipe (L7-1), and the other end is connected to the gaseous working medium pressure vessel (C2). A system flow monitoring and recovery condition extraction booster pump (L8-5) and a system flow monitoring and recovery condition one-way valve (L8-6) for restricting backflow are also provided thereon.

[0070] The system flow monitoring and recovery condition control pipeline (L8) further includes:

[0071] A system flow monitoring and recovery condition control heat exchanger (L8-2), which is located on the upstream side of the system flow monitoring and recovery condition extraction booster pump (L8-5) and is thermally coupled to the system flow monitoring and recovery condition control pipe (L8-1);

[0072] A system flow monitoring and recovery condition control temperature sensor (L8-3), which collects the fluid temperature in the system flow monitoring and recovery condition control pipe (L8-1) and is used to correspondingly control the system flow monitoring and recovery condition control heat exchanger (L8-2).

[0073] Combined with Figure 1The present application provides a precooling system for cryoablation, including a first pressure vessel (i.e., a liquid working medium pressure vessel C1), a second pressure vessel (i.e., a gaseous working medium pressure vessel C2), a first pipeline (i.e., a liquid refrigerant output pipeline L1) and a second pipeline (i.e., a precooling fluid recovery pipeline L2). The first pressure vessel is used to store liquid-phase cryogenic working medium, the second pressure vessel is used to store gaseous working medium, and the second pipeline is connected between the first pressure vessel and the second pressure vessel; the first pipeline is connected between the first pressure vessel and the cryoablation device (CP) to transport liquid-phase cryogenic working medium to the cryoablation device during the ablation process. The first pipeline is an inner and outer double-layer structure. During precooling, the liquid-phase cold working medium flows from the first pressure vessel through the inner layer of the first pipeline (i.e., the inlet channel L1-1-3), the outer layer of the first pipeline (i.e., the reflux channel L1-1-2), the second pipeline, and finally to the second pressure vessel. It can be seen that one end of the second pipeline is connected to the outer layer of the first pipeline, so that the working medium can cool the entire inner layer of the first pipeline and then flow to the second pressure vessel for recovery. The cooling method of the precooling system of the present application relies on liquid cryogenic working fluid to cool the inner layer, outer layer, etc., until the temperature of at least the inner layer meets the preset condition z, and then the precooling can be stopped. When performing cryoablation, when the corresponding working fluid is output from the inner layer to the cryoablation device, the temperature difference between the temperature of the inner layer and the working fluid is reduced or 0 compared with the existing cryoablation technology, which greatly reduces the vaporization amount of liquid cryogenic working fluid, eliminates the gas blockage phenomenon, and improves the stability and safety of the operation. In addition, the working fluid in the outer layer can form an isolation layer to block the heat exchange between the inner layer working fluid and the air outside the first pipe, thereby extending the time of the cryoablation operation.

[0074] It should be noted here that the state change of the working fluid before or after entering the second pressure vessel is not the focus, but the flow path of the working fluid. For example, the working fluid in the precooling process can be recovered to the second pressure vessel for storage, which is environmentally friendly.

[0075] The end of the first pipeline adjacent to the first pressure vessel is the first end, and the end adjacent to the cryoablation device is the second end; the inner layer of the first pipeline is connected to the first pressure vessel at the first end and to the cryoablation device at the second end, and the outer layer of the first pipeline is connected to the second pipeline at the first end and to the inner layer of the first pipeline at the second end. The isolation layer covers the entire inner layer, further reducing the amount of gasified working fluid.

[0076] In one embodiment, a first output valve (i.e., the liquid refrigerant output valve L1-2) is disposed on the first pipeline. The first output valve has an output channel (L1-2-1) communicating with the inner layer and a feedback channel (L1-2-2) communicating with the outer layer. The opening and closing of the first output valve control the opening and closing of the output channel and the feedback channel. The liquid refrigerant output valve (L1-2) includes two pairs of input-output channels, a first input-output channel (corresponding to the output channel L1-2-1) and a second input-output channel (corresponding to the reflux channel L1-2-2); the first input-output channel communicates with the liquid refrigerant pipe inflow channel (L1-1-3); the second input-output channel communicates with the liquid refrigerant pipe reflux channel (L1-1-2); the first input-output channel is used for the supply of liquid refrigerant; the second input-output channel is used for pre-cooling the valve body of the liquid refrigerant output valve (L1-2). When the liquid refrigerant output valve (L1-2) is in the open state, the fluid in the liquid refrigerant pipe inflow channel (L1-1-3) of the liquid refrigerant pipe (L1-1) dynamically flows in and out of the first input-output channel.

[0077] In this embodiment, a second solenoid valve (i.e., the pre-cooling fluid recovery solenoid valve L2-2) for controlling the on-off of the second pipeline is disposed on the second pipeline. During the pre-cooling program of the cryoablation process, the pre-cooling fluid recovery solenoid valve (L2-2) is in the open state, and the reflux fluid in the liquid refrigerant pipe reflux channel (L1-1-2) dynamically flows in and out of the second input-output channel; after the pre-cooling program of the cryoablation process ends, the pre-cooling fluid recovery solenoid valve (L2-2) is in the closed state, the reflux fluid in the liquid refrigerant pipe reflux channel (L1-1-2) stops flowing, and the fluid in the second input-output channel stops flowing.

[0078] In one embodiment, a first pressure vessel is provided with a first liquid level sensor for obtaining the first current liquid level. When the first current liquid level meets a preset condition, the first output valve is allowed to open. This avoids interruption of the flow during the pre-cooling or cryoablation process.

[0079] In another embodiment, a first temperature sensor is disposed adjacent to the second end on the first pipeline for obtaining the first current temperature of the inner layer. Preferably, the first current temperature is the temperature of the inner layer at the first end; when the first current temperature meets a preset condition, the pre-cooling ends, and the first output valve and the second solenoid valve are closed.

[0080] In one embodiment, a safety relief valve (L1-3) is disposed on the outer layer of the first pipeline. There is a liquid refrigerant pipe return channel (L1-1-2). During the pre-cooling procedure of the cryoablation process, the return fluid in the liquid refrigerant pipe return channel (L1-1-2) flows dynamically. After the pre-cooling procedure of the cryoablation process ends, the return fluid in the liquid refrigerant pipe return channel (L1-1-2) stops flowing; after the return fluid in the liquid refrigerant pipe return channel (L1-1-2) stops flowing, the fluid pressure within this layer should be restricted within the working pressure range; the safety relief valve (L1-3) prevents the pressure in the liquid refrigerant pipe return channel (L1-1-2) from being too high. When the pressure is higher than the threshold pressure of the liquid refrigerant pipe return channel, the safety relief valve (L1-3) opens and relieves pressure; when the pressure is lower than the threshold pressure of the liquid refrigerant pipe return channel, the safety relief valve (L1-3) closes.

[0081] In another embodiment, during pre-cooling, the liquid-phase cold working medium also enters the cryoablation device from the second end of the inner layer of the first pipeline. The working medium pre-cooling system further includes a seventh pipeline (i.e., the return gas recovery pipeline L7). The liquid-phase refrigerant flows through the inner layer of the first pipeline, the cryoablation device, and the seventh pipeline in sequence starting from the first pressure vessel until the second pressure vessel. The internal pipeline of the cryoablation device is also cooled to avoid the occurrence of gas blockage within the cryoablation device. Similarly, the working medium during the pre-cooling process is recovered to the second pressure vessel.

[0082] In one embodiment, the second pressure vessel is connected to the first pressure vessel through a fourth pipeline (i.e., the cryoablation working pressure boosting pipeline L4). A controlled element is disposed on the fourth pipeline. The controlled element is switched on and off correspondingly under expected conditions, so that the pressures between the first pressure vessel and the second pressure vessel are balanced with each other. The expected condition is that when the first current pressure in the first pressure vessel is lower than a preset value, the fourth pipeline is connected, so that the gaseous working medium in the second pressure vessel flows into the first pressure vessel to maintain the pressure in the first pressure vessel within the working pressure range, enabling the continuous output of the liquid-phase refrigerant. Wherein the controlled element is a fourth pressure control element and a fourth solenoid valve connected in series between the second pressure vessel and the first pressure vessel. The fourth solenoid valve opens when the first current pressure reaches the first pressure preset value to connect the second pressure vessel and the first pressure vessel, and the fourth pressure control element automatically controls its output pressure to be less than its input pressure.

[0083] The seventh pipeline and the second pipeline are connected to the second pressure vessel through a booster pump (L8-5) to increase the pressure of the working medium in the seventh pipeline and the second pipeline and then transport it to the second pressure vessel, so that the working medium can circulate. Among them, when the pre-cooling ends (when the first current temperature meets the preset conditions), the booster pump is delayed to close, so that the working medium in the second pipeline and the seventh pipeline is recovered clean before cryoablation. The delayed closing can be realized by setting a system timer in the system.

[0084] Among them, a first one-way valve (L1-6) is configured on the first pipeline to prevent the liquid working medium from flowing back.

[0085] The working medium pre-cooling system for cryoablation of the present application is modified on the original cryoablation system. The first pipeline for transporting the working medium is divided into an inner layer and an outer layer. The pre-cooling system can effectively reduce the gasification amount of the working medium during cryoablation and eliminate gas blockage. And the working medium in the outer layer serves as an isolation layer to limit the heat exchange between the working medium in the inner layer and the air outside the first pipeline, prolonging the cryoablation time. Especially during cryoablation surgery, the stability and safety are improved. And a corresponding pipeline for recovering the working medium is added, which is environmentally friendly and economical.

[0086] Combined Figures 1 to 6 , the present application provides a conveying device for conveying a working medium from a first pressure vessel (i.e., a liquid working medium pressure vessel C1) to a cryoablation device (CP). The working medium is in a low-temperature and gas-liquid two-phase state during transportation, and the first pressure vessel is used to store the liquid working medium and can convey the working medium through a power device or its own pressure.

[0087] First, the conveying device includes a first pipeline (liquid refrigerant output pipeline L1) and a gas-liquid separation device. The inner and outer layer structures of the first pipeline in the above embodiments can be understood as including an outer pipe (L1-1-4) and an isolation sleeve (L1-1-5) located in the outer pipe. The outer pipe and the isolation sleeve form a liquid refrigerant pipe (L1-1), and the isolation sleeve divides the first pipeline into an inner and outer double-layer structure in the radial direction.

[0088] The gas-liquid separation device is of a cylindrical structure and is arranged inside the isolation sleeve. The first end of the cylindrical structure is open, and the second end is closed. The interior of the cylindrical structure is the first channel (i.e., the base tube L1-1-4-2 of the gas-liquid separation device), and the space between the outer wall of the cylindrical structure and the inner wall of the isolation sleeve is the second channel. The side wall of the cylindrical structure is provided with a through hole (i.e., the exhaust hole L1-1-4-3) that communicates the first channel and the second channel. Due to the setting of the through hole, part of the working medium will enter the first channel, and the gas mass flow rate of this part of the two-phase flow is higher than the liquid mass flow rate. The two-phase flow that flows through the second channel and does not enter the base tube (L1-1-4-2) of the liquid cryogen tube has a liquid mass flow rate higher than the gas mass flow rate. Thereby reducing the gasification amount of the working medium in the second channel and reducing the probability of gas blockage during precooling or ablation. Since the second end of the gas-liquid separation device is closed, the working medium that enters the first channel will flow towards the first end, which is opposite to the flow direction of the working medium in the second channel. Further analyzing in combination with the flow path of the working medium in the first path, the flow path of the working medium is also divided into two paths: the third path is through the second channel until the cryoablation device or the outer layer; the fourth path is through the second channel, the through hole, the first channel until the first end of the first channel.

[0089] In this embodiment, the working medium stored in the first pressure vessel is liquid nitrogen, which reduces the proportion of liquid nitrogen gasification affected by temperature, and at the same time separates the nitrogen gas gasified due to inevitable factors such as friction from the liquid nitrogen, avoiding the gas blockage phenomenon, making the output liquid nitrogen dose stable and controllable, and achieving a stable cryoablation effect.

[0090] The method of reducing gas blockage can be to reduce the temperature difference between the inner layer temperature and the working medium during cryoablation. For example, in another embodiment, the liquid cryogen tube (L1-1) is of a sleeve structure, including at least two or more sleeve structures; it has: a heat insulation channel of the liquid cryogen tube, a return channel of the liquid cryogen tube (L1-1-2), an inflow channel of the liquid cryogen tube (L1-1-3), and a gas-liquid separation device of the liquid cryogen tube (L1-1-4). The three channels from the outside to the inside of the liquid cryogen tube (L1-1) are the heat insulation channel (L1-1-1), the return channel (L1-1-2), and the inflow channel (L1-1-3) in sequence. The heat insulation channel can communicate with the return channel (L1-1-2) and flow through the same working medium, or it can be not connected to the return channel (L1-1-2) and the inflow channel (L1-1-3) and flow through other low-temperature working media to further block heat exchange. In other embodiments, heat exchange is blocked by setting a thermal insulation layer on the outer layer.

[0091] The outer wall of the cylindrical structure is provided with diversion grooves for forming a second channel. The diversion grooves communicate with the first end and the second end, enabling the working medium to flow on the diversion grooves. In order to achieve effective gas-liquid separation, through holes are opened on the groove walls of the diversion grooves. Among them, the outer wall of the cylindrical mechanism is in contact with the inner wall of the isolation sleeve, and the diversion grooves are of a groove structure. Then the working medium can only flow through the diversion grooves, and thus the working medium must pass through the through holes, improving the gas-liquid separation efficiency. In the cross-section, the second channel is formed by the groove wall of the diversion groove and the inner wall of the isolation sleeve. Among them, the groove wall of the diversion groove is arc-shaped and the groove wall is smooth, reducing the heat generated by friction with the working medium. The opening position of the through hole is at the bottom of the arc, and the shape of the through hole is circular, which is convenient for processing.

[0092] Combined with Figure 3 , in order to further improve the separation efficiency, the methods adopted are that the diversion grooves are spirally wound around the outer wall of the cylindrical structure to form a spiral channel, extending the flow path of the working medium. Or there are multiple through holes arranged along the diversion grooves. Among them, 1 to 8 through holes are arranged in each circle of the spiral winding of the diversion grooves, and these through holes are equally spaced in the circumferential direction of the cylindrical structure.

[0093] In an embodiment, the first end of the isolation sleeve extends out of the first end of the outer tube, and this extended part serves as an inserting bottom tube, and the length can at least extend below the liquid level in the first pressure vessel, so that pre-cooling and ablation can continuously output the liquid working medium. And the first end of the outer tube is outside the first pressure vessel, so that the working medium flows out after passing through the second end and then returning to the first end of the outer layer after output from the first end of the inner layer, so that most or all of the inner layer is cooled.

[0094] The axial positions of the first end of the cylindrical structure and the first end of the isolation sleeve are adjacent to each other. Being adjacent to each other means that the first end of the gas-liquid separation device is also below the liquid level in the first pressure vessel. Then the working medium directly enters the second channel for gas-liquid separation when output, and the working medium entering the first channel can return to the first pressure vessel and liquefy, realizing local circulation and saving resources.

[0095] Combined with Figure 4, in one embodiment, an output valve (i.e., the liquid refrigerant output valve L1-2) is arranged on the first pipeline. The output valve has an output channel (L1-2-1) communicating with the inner layer and a return channel (L1-2-2) communicating with the outer layer. The liquid refrigerant output valve (L1-2) includes two pairs of input-output channels, the first input-output channel (corresponding to the output channel) and the second input-output channel (corresponding to the return channel); the first input-output channel communicates with the liquid refrigerant pipe inflow channel (L1-1-3); the second input-output channel communicates with the liquid refrigerant pipe return channel (L1-1-2); when the liquid refrigerant output valve (L1-2) is in the open state, the fluid in the liquid refrigerant pipe inflow channel (L1-1-3) of the liquid refrigerant pipe (L1-1) dynamically flows in and out of the first input-output channel.

[0096] The gas-liquid separation device of the present application can improve the liquid mass flow rate of the working medium transported to the cryoablation device, and further reduce the gas blockage phenomenon.

[0097] The above embodiment completes the precooling of the first pipeline. Next, it is necessary to pressurize the first pressure vessel C1 and the second pressure vessel C2 to reach the pressure required for subsequent cryoablation.

[0098] The present application also provides a working medium pressure vessel system for cryoablation, including a first pressure vessel (i.e., the liquid working medium pressure vessel (C1)), a second pressure vessel (i.e., the gas working medium pressure vessel (C2)), and a third pressure vessel (i.e., the phase change pressure vessel (C3)). The first pressure vessel is used to store the liquid working medium and supply the liquid working medium to the cryoablation device (CP) during the ablation process. The working medium will be discharged after passing through the cryoablation device. The second pressure vessel is used to store the gas working medium and is controllably connected to the first pressure vessel through the fourth pipeline (i.e., the cryoablation working pressure control element L4-3), and at the same time receives the returned working medium from the cryoablation device. The third pressure vessel is arranged inside the first pressure vessel to phase-change the liquid working medium into a gas working medium. The third pressure vessel is controllably connected to the first pressure vessel through a one-way flow device to receive the liquid working medium, and the third pressure vessel is also controllably connected to the second pressure vessel through the fifth pipeline.

[0099] Controlled elements are respectively arranged on the fourth pipeline and the fifth pipeline. Each controlled element and the one-way flow device are respectively switched on and off under the condition of meeting the expected conditions, so that the pressures of the first pressure vessel, the second pressure vessel, and the third pressure vessel are related.

[0100] First of all, the returned working medium is the working medium discharged by the cryoablation device, and the second pressure vessel and the cryoablation device can be connected through a pipeline to realize the flow of the returned working medium. This process is the working medium recovery process. It should be noted here that the state change of the working medium during the recovery process is not the focus.

[0101] Secondly, in the pressure linkage process among the three pressure vessels, the working medium in the third pressure vessel enters the second pressure vessel for pressure compensation to maintain the second pressure vessel within a preset pressure range; the working medium of the second pressure vessel enters the first pressure vessel for pressure compensation to maintain the first pressure vessel within a preset pressure range, and can continuously output the liquid working medium; the third pressure vessel maintains its own pressure within the preset pressure range by changing the state of the working medium. Each of the above pressure vessels corresponds to a preset pressure range. This pressure linkage process uses the existing second pressure vessel as a transition to achieve the overall automatic pressure circulation control. The pressure vessel system in this embodiment is mainly used to control the pressure in the liquid working medium pressure vessel (C1), the gaseous working medium pressure vessel (C2), the phase change pressure vessel (C3), and the liquid delivery pipeline (L1) to be maintained within the working pressure range. The working pressure of the pressure vessel: phase change pressure vessel (C3) > gaseous working medium pressure vessel (C2) > liquid working medium pressure vessel (C1).

[0102] In the following embodiments, liquid nitrogen is taken as an example for the liquid working medium, and gaseous nitrogen corresponds to the gaseous working medium.

[0103] The first pressure vessel is equipped with a first pressure sensor (i.e., the liquid working medium pressure sensor C1-1) to obtain the first current pressure; the controlled components on the fourth pipeline are the fourth pressure control component (i.e., the cryoablation working pressure control component L4-3) and the fourth solenoid valve (i.e., the booster solenoid valve L4-2) connected in series between the second pressure vessel and the first pressure vessel in sequence. The fourth solenoid valve opens when the first current pressure reaches the first pressure preset value to connect the second pressure vessel and the first pressure vessel, and the fourth pressure control component automatically controls its output pressure to be less than its input pressure. The second pressure vessel is mainly used to compensate and increase the pressure in the first pressure vessel. Of course, when the first pressure vessel is overpressured, pressure reduction is also required. In one embodiment, the first pressure vessel is equipped with an exhaust and pressure relief pipeline, and a solenoid valve (i.e., the pressure reducing solenoid valve L3-2) that opens at a preset pressure to implement pressure relief is provided on each exhaust and pressure relief pipeline.

[0104] For the automatic pressure control of the first pressure vessel:

[0105] The working pressure of the liquid working medium pressure vessel (C1) is maintained within the desired range through the cryoablation working pressure reduction pipeline (L3), the cryoablation working pressure increase pipeline (L4), and the liquid working medium pressure sensor (C1-1); the liquid working medium pressure sensor (C1-1) collects the first current pressure of the liquid working medium pressure vessel (C1), and the first current pressure participates in judging whether the working pressure of the liquid working medium pressure vessel (C1) is within the desired range.

[0106] The working pressure is the nominal pressure of the liquid medium pressure vessel (C1), and the working pressure range is the pressure range in which the liquid medium pressure vessel (C1) exists corresponding to the nominal pressure; the pressure range takes the working pressure as the median value, with an upper deviation relative to the median value as the upper limit of the pressure range and a lower deviation relative to the median value as the lower limit of the pressure range; the working pressures of different liquid medium pressure vessels (C1) correspond to their respective pressure ranges, that is, the aforementioned working pressure range

[0107] When the pressure collected by the liquid medium pressure sensor (C1-1) drops to the first pressure boost start threshold, the pressure boost solenoid valve (L4-2) in the cryoablation working pressure boost pipeline (L4) opens, and the gaseous medium in the gaseous medium pressure vessel (C2) enters the liquid medium pressure vessel (C1) through the cryoablation working pressure boost pipe (L4-1) for pressure boosting; when the pressure collected by the liquid medium pressure sensor (C1-1) is higher than the first pressure boost stop threshold, the pressure boost solenoid valve (L4-2) in the cryoablation working pressure boost pipeline (L4) closes.

[0108] The working pressure of the liquid medium pressure vessel (C1) is dynamically maintained within the working pressure range. When the pressure collected by the liquid medium pressure sensor (C1-1) is higher than the first pressure reduction start threshold, the pressure reduction solenoid valve (L3-2) in the cryoablation working pressure reduction pipeline (L3) opens, and the gaseous medium in the liquid medium pressure vessel (C1) is discharged to the atmosphere through the cryoablation working pressure reduction pipe (L3-1) for pressure reduction; when the pressure collected by the liquid medium pressure sensor (C1-1) is lower than the first pressure reduction stop threshold, the pressure reduction solenoid valve (L3-2) in the cryoablation working pressure reduction pipeline (L3) closes.

[0109] The first pressure boost start threshold, the first pressure boost stop threshold, the first pressure reduction start threshold, and the first pressure reduction stop threshold dynamically maintain the working pressure of the liquid medium pressure vessel (C1) within the working pressure range; the first pressure boost start threshold < the first pressure boost stop threshold; the first pressure reduction start threshold > the first pressure reduction stop threshold; the lower limit of the working pressure range of the liquid medium pressure vessel (C1) < the first pressure boost start threshold; the upper limit of the working pressure range of the liquid medium pressure vessel (C1) > the first pressure reduction start threshold.

[0110] In one embodiment, a second pressure sensor (i.e., gaseous working medium pressure sensor C2-1) is disposed on the second pressure vessel to obtain the second current pressure. The controlled components on the fifth pipeline are a fifth solenoid valve (i.e., gaseous working medium output solenoid valve L5-4) and a fifth pressure control component (i.e., gaseous working medium output pressure control component L5-5) that are serially connected in sequence between the third pressure vessel and the second pressure vessel. The fifth solenoid valve opens when the second current pressure is lower than the second pressure preset value to connect the third pressure vessel and the second pressure vessel. The fifth pressure control component automatically controls its output pressure to be less than its input pressure. Of course, when the second pressure vessel is overpressured, pressure relief is also required. In one embodiment, the second pressure vessel is configured with an exhaust pressure relief pipeline, and a solenoid valve (i.e., gaseous working medium pressure relief valve C2-2) that opens at a preset pressure to implement pressure relief is provided on the exhaust pressure relief pipeline.

[0111] The automatic control of the second pressure vessel is as follows:

[0112] The working pressure of the gaseous working medium pressure vessel (C2) is dynamically maintained within the working pressure range through the gaseous working medium output pipeline (L5), the gaseous working medium pressure sensor (C2-1), and the gaseous working medium pressure relief valve (C2-2). The gaseous working medium pressure sensor (C2-1) collects the second current pressure of the gaseous working medium pressure vessel (C2), and the second current pressure participates in judging whether the working pressure of the gaseous working medium pressure vessel (C2) is within the desired range.

[0113] The working pressure of the gaseous working medium pressure vessel (C2) is dynamically maintained within the working pressure range. When the pressure collected by the gaseous working medium pressure sensor (C2-1) drops to the second pressure increase opening threshold, the gaseous working medium output solenoid valve (L5-4) in the gaseous working medium output pipeline (L5) opens, and the gaseous working medium in the phase change pressure vessel (C3) enters the gaseous working medium pressure vessel (C2) after being decompressed by the gaseous working medium output pressure control component (L5-5) through the gaseous working medium output pipe (L5-1) to perform pressure increase compensation on the second pressure vessel. When the pressure collected by the gaseous working medium pressure sensor (C2-1) is higher than the second pressure increase closing threshold, the gaseous working medium output solenoid valve (L5-4) in the gaseous working medium output pipeline (L5) closes.

[0114] The working pressure of the gaseous working medium pressure vessel (C2) is dynamically maintained within the working pressure range. When the pressure collected by the gaseous working medium pressure sensor (C2-1) is higher than the second pressure reduction opening threshold, the gaseous working medium pressure relief valve (C2-2) opens, and the gaseous working medium pressure vessel (C2) is discharged to the atmosphere through the gaseous working medium pressure relief valve (C2-2) for pressure reduction. When the pressure collected by the gaseous working medium pressure sensor (C2-1) is lower than the second pressure reduction closing threshold, the gaseous working medium pressure relief valve (C2-2) closes.

[0115] The second supercharging opening threshold, the second supercharging closing threshold, the second decompression opening threshold, and the second decompression closing threshold dynamically maintain the working pressure of the gaseous working medium pressure vessel (C2) within the working pressure range; the second supercharging opening threshold < the second supercharging closing threshold; the second decompression opening threshold > the second decompression closing threshold; the lower limit of the working pressure range of the gaseous working medium pressure vessel (C2) < the second supercharging opening threshold; the upper limit of the working pressure range of the gaseous working medium pressure vessel (C2) > the second decompression opening threshold.

[0116] In one embodiment, a third pressure sensor (i.e., the phase change pressure transmitter L5-2) for monitoring the third pressure vessel is arranged on the fifth pipeline (i.e., the gaseous working medium output pipeline L5) to obtain the third current pressure. A heating device (i.e., the phase change heating device C3-2) is arranged on the third pressure vessel to heat the liquid working medium in the third pressure vessel into a gaseous working medium and increase the third current pressure. When the third current pressure reaches the third pressure preset value, the heating device stops heating.

[0117] In this embodiment, a liquid level sensor (C3-4) and a temperature sensor (C3-5) are arranged on the third pressure vessel to obtain the third current liquid level and the third current temperature, and the third current liquid level and the third current temperature participate in the judgment of controlling the heating device. When the third current liquid level and the third current temperature meet the expected conditions, the heating device stops heating.

[0118] Refer to Figure 6 , one end of the gaseous working medium output pipeline (L5) fixed to the top end cover of the liquid working medium pressure vessel (C1) extends into the phase change pressure vessel (C3); the bottom of the phase change pressure vessel (C3) is provided with a liquid working medium one-way flow device (C3-1), which can be understood to be below the liquid level in the first pressure vessel. The liquid working medium in the liquid working medium pressure vessel (C1) can enter the phase change pressure vessel (C3) through the liquid working medium one-way flow device (C3-1), and the liquid working medium one-way flow device (C3-1) prevents the liquid or gaseous working medium from entering the liquid working medium pressure vessel (C1) from the phase change pressure vessel (C3). The phase change heating device (C3-2) is located in the phase change pressure vessel (C3). In order to avoid the influence on the liquid working medium in the first container during the heating process, a heat insulation layer (i.e., the container heat insulation layer (C3-3)) for isolating heat conduction is arranged on the third pressure vessel. The container heat insulation layer (C3-3) thermally isolates the phase change pressure vessel (C3) from the liquid working medium pressure vessel (C1).

[0119] Automatic pressure control of the third pressure vessel (i.e., the phase change pressure vessel C3):

[0120] The gaseous working medium in the phase change pressure vessel (C3) can enter the gaseous working medium pressure vessel (C2) through the gaseous working medium output pipeline (L5).

[0121] The working pressure of the phase change pressure vessel (C3) is dynamically maintained within the working pressure range through the gaseous working medium output pipeline (L5), the liquid working medium unidirectional flow device (C3-1), the phase change heating device (C3-2), as well as the phase change pressure transmitter (L5-2), the liquid level sensor (C3-4), and the temperature sensor (C3-5); the phase change pressure transmitter (L5-2) collects the third current pressure of the phase change pressure vessel (C3), and the third current pressure participates in judging whether the working pressure of the phase change pressure vessel (C3) is within the expected range.

[0122] The working pressure of the phase change pressure vessel (C3) is dynamically maintained within the working pressure range. During the period when the pressure collected by the phase change pressure transmitter (L5-2) increases from the third pressure boost start threshold to the third pressure boost stop threshold, the liquid level information of the liquid level sensor (C3-4) and the temperature information of the temperature sensor (C3-5) participate in judging whether the pressure boost process is effective:

[0123] During the period when the pressure collected by the phase change pressure transmitter (L5-2) increases from the third pressure boost start threshold to the third pressure boost stop threshold, when the liquid level collected by the liquid level sensor (C3-4) < the first low liquid level threshold and the temperature collected by the temperature sensor (C3-5) < the first high temperature threshold, the pressure collected by the phase change pressure transmitter (L5-2) > the third pressure boost lower limit threshold, the pressure boost process ends, and the phase change heating device (C3-2) stops heating, and this pressure boost process is effective; when the liquid level collected by the liquid level sensor (C3-4) < the first low liquid level threshold and the temperature collected by the temperature sensor (C3-5) > the first high temperature threshold, the pressure collected by the phase change pressure transmitter (L5-2) < the third pressure boost lower limit threshold, the pressure boost process ends, and the phase change heating device (C3-2) stops heating, and this pressure boost process is invalid, and the above-mentioned pressure boost process is repeated.

[0124] Of course, during the entire pressure linkage process, the phase change pressure vessel (C3) may experience overpressure. Therefore, the third pressure vessel is equipped with an exhaust and pressure relief pipeline, and a solenoid valve (i.e., the phase change vessel pressure relief solenoid valve (L5-3)) that opens at a preset pressure to implement pressure relief is provided on the exhaust and pressure relief pipeline, so that the third current pressure is dynamically maintained within the working pressure range. In this embodiment, the phase change vessel pressure relief solenoid valve (L5-3) is provided on the gaseous working medium output pipe (L5-1). When the pressure collected by the phase change pressure transmitter (L5-2) drops to the third pressure reduction opening threshold, the phase change vessel pressure relief solenoid valve (L5-3) in the gaseous working medium output pipeline (L5) opens, and the gaseous working medium in the phase change pressure vessel (C3) is discharged to the atmosphere through the gaseous working medium output pipe (L5-1) via the phase change vessel pressure relief solenoid valve (L5-3) for pressure reduction. When the pressure collected by the phase change pressure transmitter (L5-2) drops to the third pressure reduction closing threshold, the phase change vessel pressure relief solenoid valve (L5-3) in the gaseous working medium output pipeline (L5) closes.

[0125] The third pressure increase opening threshold, the first liquid level closing threshold, the third pressure increase closing threshold, the first low liquid level threshold, the first high temperature threshold, the third pressure increase lower limit threshold, the third pressure reduction opening threshold, and the third pressure reduction closing threshold dynamically maintain the working pressure of the phase change pressure vessel (C3) within the working pressure range; the third pressure increase opening threshold < the third pressure increase lower limit threshold < the third pressure increase closing threshold; the third pressure reduction opening threshold > the third pressure reduction closing threshold; the lower limit of the working pressure range of the phase change pressure vessel (C3) < the third pressure increase opening threshold; the upper limit of the working pressure range of the phase change pressure vessel (C3) > the third pressure reduction opening threshold; the first liquid level closing threshold > the first low liquid level threshold; the first high temperature threshold ≤ room temperature; the first low liquid level threshold, the first high temperature threshold, and the third pressure increase lower limit threshold are involved in the judgment of the pressure increase effectiveness of the phase change pressure vessel (C3).

[0126] The working pressure of the liquid working medium pressure vessel (C1), the working pressure of the gaseous working medium pressure vessel (C2), the working pressure of the phase change pressure vessel (C3), the first pressure increase opening threshold, the first pressure increase closing threshold, the first pressure reduction opening threshold, the first pressure reduction closing threshold, the second pressure increase opening threshold, the second pressure increase closing threshold, the second pressure reduction opening threshold, the second pressure reduction closing threshold, the third pressure increase opening threshold, the first liquid level closing threshold, the third pressure increase closing threshold, the first low liquid level threshold, the first high temperature threshold, the third pressure increase lower limit threshold, the third pressure reduction opening threshold, and the third pressure reduction closing threshold dynamically maintain the respective working pressures of the pressure vessels: the liquid working medium pressure vessel (C1), the gaseous working medium pressure vessel (C2), and the phase change pressure vessel (C3) within their respective working pressure ranges.

[0127] Dynamically maintain the working pressure of the pressure vessel within the working pressure range. The freezing ablation working pressure boosting solenoid valve (L4-2), the gaseous working medium output solenoid valve (L5-4), and the phase change vessel pressure relief solenoid valve (L5-3) are involved in the pressurization process of the pressure vessel; the freezing ablation working pressure reducing solenoid valve (L3-2), the gaseous working medium pressure relief valve (C2-2), and the phase change vessel pressure relief solenoid valve (L5-3) are involved in the depressurization process of the pressure vessel; it is prohibited for the freezing ablation working pressure boosting solenoid valve (L4-2) and the freezing ablation working pressure reducing solenoid valve (L3-2) to work simultaneously; it is prohibited for the gaseous working medium output solenoid valve (L5-4) and the gaseous working medium pressure relief valve (C2-2) to work simultaneously.

[0128] The working pressure range corresponding to each pressure vessel is dynamic. The specific method for setting the range is as follows:

[0129] Refer to Figure 1 , between the freezing ablation device and the second pressure vessel, they are connected through the seventh pipeline (i.e., the return gas recovery pipeline L7) and the eighth pipeline (i.e., the system flow monitoring and recovery condition control pipeline L8). The eighth pipeline is equipped with a system flow monitoring and recovery condition control flowmeter (L8-4), and the setting of the working pressure range can be adjusted according to the flow data of the system flow monitoring and recovery condition control flowmeter (L8-4) in the system flow monitoring and recovery condition control pipeline (L8).

[0130] Among them, the pressure compensation for C1 in the above embodiments can be executed at any stage.

[0131] In a freezing ablation system using nitrogen or liquid nitrogen as the freezing working medium, it is necessary to heat liquid nitrogen to generate nitrogen for freezing or rewarming. However, liquid nitrogen is extremely easy to vaporize, and a large amount of nitrogen will be rapidly generated after heating, resulting in a rapid increase in the pressure inside the container and a relatively high safety risk. In the above embodiments, through a one-way flow device responsive to pressure control, the liquid nitrogen in the liquid nitrogen container can be controllably introduced into the heating device with a heat insulation structure, thereby controlling the amount of liquid nitrogen vaporization and improving the safety during liquid nitrogen vaporization.

[0132] Combined with Figure 7A 、 Figure 7B And further elaborating on the structure of the phase change pressure vessel C3 as described above, the bottom of the phase change pressure vessel (C3) is provided with a liquid working medium one-way flow device, the top is connected with a gaseous working medium output solenoid valve, and a phase change heating device is arranged inside. The liquid working medium one-way flow device has an internal space, and the liquid working medium one-way flow device is provided with a bottom port communicating with the internal space, a top port communicating with the inside of the phase change pressure vessel (C3), a side wall port communicating the internal space and the inside of the phase change pressure vessel (C3), and a one-way flow device blocking ball (C3-1-4) slidably installed in the internal space;

[0133] The sealing plate (C3-1-2) that is movably sealed in the internal space has one side facing the top port and the other side linked to the sealing ball of the one-way flow device. Under the action of the internal pressure of the phase change pressure vessel (C3), the sealing ball of the one-way flow device is driven to seal the bottom port, and the sealing plate avoids the side wall port in its own movement stroke. The sealing plate is adapted to the internal space and can allow the liquid working medium to flow in from the bottom port and then flow out from the side wall port to prevent the liquid working medium from flowing out from the top port. The sealing plate is subjected to the pressure from the phase change pressure vessel C3 (the pressure generated by the liquid and / or gaseous working medium) on the side facing the top port, and the pressure is indirectly transmitted to the sealing ball. The sealing ball is also subjected to the pressure from the first pressure vessel at the bottom port. The interaction of the two pressures causes the sealing ball to move, and the corresponding bottom port is opened or sealed.

[0134] The phase change heating device is used to heat the liquid working medium in the phase change pressure vessel C3 to gasify it to increase the pressure of the phase change pressure vessel and prepare for the subsequent pressure construction of the second pressure vessel C2. For example, when the pressure in the third pressure vessel meets the preset conditions, the gaseous working medium output solenoid valve opens and delivers the gaseous working medium to the second pressure vessel.

[0135] The top of the phase change pressure vessel (C3) is connected to a phase change vessel pressure relief solenoid valve (L5-3), and the phase change pressure vessel (C3) is also equipped with a liquid level sensor (C3-4), a temperature sensor (C3-5), a phase change pressure transmitter (L5-2) and a container insulation layer (C3-3). A stopper (C3-1-1) is fixed in the internal space, and the sealing ball of the one-way flow device moves away from the bottom opening to the limit position under the external pressure of the bottom opening, and the position of the stopper is on the side of the sealing plate facing the top opening and against the sealing plate.

[0136] The present application also provides a control method for a phase change pressure system, comprising:

[0137] The liquid working medium one-way flow device is turned on;

[0138] The liquid working medium in the liquid working medium pressure vessel (C1) enters the phase change pressure vessel (C3) through the liquid working medium one-way flow device (C3-1);

[0139] The phase change heating device is used to heat and gasify the liquid working medium in the phase change pressure vessel (C3).

[0140] The condition for opening the liquid working medium unidirectional flow device is that the pressure of the liquid working medium pressure vessel (C1) is low.

[0141] The condition for the liquid working medium to flow into the phase change pressure vessel is that the pressure or liquid level of the liquid working medium pressure vessel (C1) meets the expected

[0142] The condition for the liquid working fluid to be vaporized by heat is that the pressure of the liquid working fluid pressure vessel (C1) meets the expectation.

[0143] As Figure 7A , in the initial state, when the pressure in the phase change pressure vessel (C3) is close to the atmospheric pressure (which can be achieved by the phase change vessel pressure relief solenoid valve (L5-3)), the pressure in the liquid working medium pressure vessel (C1) > the pressure in the phase change pressure vessel (C3) in the current state. Under the action of the static pressure (C3-1-5) in the liquid working medium pressure vessel (C1), the one-way flow device blocking ball (C3-1-4) is pushed upward to compress the spring (C3-1-3). Under the action of the stop block (C3-1-1), the sealing plate (C3-1-2) connected to the spring (C3-1-3) cannot move upward continuously; at this time, the liquid working medium in the liquid working medium pressure vessel (C1) enters the phase change pressure vessel (C3) through the side wall opening of the liquid working medium containing one-way flow device (C3-1) through the flow path (C3-1-6). The sealing plate (C3-1-2) and the side wall of the liquid working medium one-way flow device (C3-1) are in a dynamic sealing structure; therefore, under the above structure, the fluid path (C3-1-6) is the only one.

[0144] As Figure 7B , after the liquid working medium in the liquid working medium pressure vessel (C1) enters the phase change pressure vessel (C3), the phase change heating device (C3-2) continuously heats the liquid working medium entering the phase change pressure vessel (C3), so as to further increase the pressure in the phase change pressure vessel (C3). Under the action of the static pressure (C3-1-5) in the phase change pressure vessel (C3), the sealing plate (C3-1-2) connected to the spring (C3-1-3) is pushed downward to compress the spring (C3-1-3), and further the one-way flow device blocking ball (C3-1-4) closes the liquid working medium one-way flow device (C3-1), so that the flow path (C3-1-6) cannot pass through the blocking area of the liquid working medium one-way flow device (C3-1).

[0145] Participate Figure 8 , in another embodiment, the liquid working medium one-way flow device (C3-1) is a cryogenic fluid micro pump.

[0146] Corresponding control method: When the phase change pressure vessel (C3) is released through the phase change vessel pressure relief solenoid valve (L5-3), the cryogenic fluid micro pump is turned on to pump the liquid working medium in the liquid working medium pressure vessel (C1) to the phase change pressure vessel (C3). Then, when the liquid level information collected by the liquid level sensor (C3-4) reaches the threshold value, the cryogenic fluid micro pump is turned off. Further, the phase change heating device (C3-2) continuously heats the liquid working medium entering the phase change pressure vessel (C3) to further increase the pressure in the phase change pressure vessel (C3).

[0147] During system operation, the working pressure of the phase change pressure vessel (C3) is dynamically maintained within the working pressure range. When the pressure collected by the phase change pressure transmitter (L5-2) drops to the third pressure boosting start threshold, the phase change vessel pressure relief solenoid valve (L5-3) in the gaseous working medium output pipeline (L5) opens, and the gaseous working medium in the phase change pressure vessel (C3) is discharged to the atmosphere through the gaseous working medium output pipe (L5-1) via the phase change vessel pressure relief solenoid valve (L5-3), causing the pressure collected by the phase change pressure transmitter (L5-2) to further drop to the liquid working medium one-way flow device start threshold. The liquid working medium in the liquid working medium pressure vessel (C1) enters the phase change pressure vessel (C3) through the liquid working medium one-way flow device (C3-1); the liquid level sensor (C3-4) collects the liquid level data of the liquid working medium entering the phase change pressure vessel (C3). When the liquid level reaches the first liquid level closing threshold, the phase change vessel pressure relief solenoid valve (L5-3) in the gaseous working medium output pipeline (L5) closes, and the phase change heating device (C3-2) is started to vaporize the liquid working medium into a gaseous working medium to increase the pressure in the phase change pressure vessel (C3). As the pressure increases, the liquid working medium one-way flow device (C3-1) is prompted to close; the phase change heating device (C3-2) continuously heats the liquid working medium entering the phase change pressure vessel (C3) to further boost the pressure of the phase change pressure vessel (C3); when the pressure collected by the phase change pressure transmitter (L5-2) is higher than the third pressure boosting closing threshold, the phase change heating device (C3-2) stops heating.

[0148] See the appendix Figure 1 In one embodiment of the present application, a low-pressure fluid system for enhancing the performance of interventional cryoablation is disclosed, including at least one of the following: a liquid working medium pressure vessel (C1), a gaseous working medium pressure vessel (C2), a phase change pressure vessel (C3), a liquid refrigerant output pipeline (L1), a precooling fluid recovery pipeline (L2), a cryoablation working pressure reducing pipeline (L3), a cryoablation working pressure boosting pipeline (L4), a gaseous working medium output pipeline (L5), a replacement and rewarming pipeline (L6), a return gas recovery pipeline (L7), a system flow monitoring and recovery condition control pipeline (L8), a vacuum degree creation pipeline (L9), and a cryoablation device (CP) as a cryoablation equipment.

[0149] The above-mentioned modules, containers, pipelines, and related equipment and methods can be applied to low-pressure cryoablation, such as less than 3 MPa (such as a working pressure of about 0.5 MPa). Each can independently implement certain unit operations, and in some cases, they can also be integrated with each other into a relatively complete low-pressure fluid system. The following will separately describe each component, but it is not strictly limited that they must be configured simultaneously:

[0150] 1) Pressure vessels for containing liquid and gaseous working fluids: a pressure vessel for liquid working fluid (the first pressure vessel C1), a pressure vessel for gaseous working fluid (the second pressure vessel C2), and a phase change pressure vessel (the third pressure vessel C3).

[0151] ① The first pressure vessel (C1), in which a liquid working fluid is stored inside. It is connected to the cryoablation device CP through the first pipeline L1 to transport the liquid working fluid.

[0152] The first pressure vessel C1 is connected to the second pressure vessel C2 through the fourth pipeline L4; a third pressure vessel C3 is arranged inside the first pressure vessel C1, which can transform the liquid working fluid into a gaseous working fluid.

[0153] The first pressure vessel C1 is provided with a third pipeline L3 for exhaust and pressure relief.

[0154] The pressure vessel for liquid working fluid (C1), preferably a Dewar pressure vessel, is used to store the liquid working fluid during the freezing process in the cryoablation procedure; it includes: a liquid working fluid pressure sensor (C1-1), a liquid working fluid level sensor (C1-2).

[0155] ② The pressure vessel for gaseous working fluid (i.e., the second pressure vessel C2), in which a gaseous working fluid is stored inside. It is connected to the first pressure vessel (C1) through the fourth pipeline L4 and transports the gaseous working fluid to the first pressure vessel (C1).

[0156] The second pressure vessel (C2) is connected to the third pressure vessel (C3) through the fifth pipeline (L5) and receives the gaseous working fluid from inside the third pressure vessel (C3).

[0157] The second pressure vessel (C2) is connected to the cryoablation device (CP) through the sixth pipeline (L6) and transports the heated gaseous working fluid.

[0158] The second pressure vessel (C2) is connected to the gaseous working fluid of the cryoablation device (CP) and / or the first pipeline (L1) through the eighth pipeline (L8).

[0159] Preferably a Dewar pressure vessel, it is used to store the gaseous working fluid during the pre-displacement, rewarming process and the recovery of the return air passage in the cryoablation procedure; it includes: a gaseous working fluid pressure sensor (C2-1), a gaseous working fluid pressure relief valve (C2-2).

[0160] ③ The phase change pressure vessel (i.e., the third pressure vessel C3), which is connected through the fifth pipeline (L5) and transports to the second pressure vessel (C2).

[0161] It is used to phase-change a liquid working medium into a gaseous working medium, and the phase-changed gas is transported to a gaseous working medium pressure vessel (C2) through a gaseous working medium output pipeline (L5) via a pressure control element (L5-5). It includes: a liquid working medium one-way flow device (C3-1), a phase-change heating device (C3-2), a container heat insulation layer (C3-3), a liquid level sensor (C3-4), and a temperature sensor (C3-5).

[0162] 2) Nine functional pipelines containing valves, sensors, and control elements: a liquid refrigerant output pipeline (the first pipeline L1), a precooling fluid recovery pipeline (the second pipeline L2), a cryoablation working pressure reduction pipeline (the third pipeline L3), a cryoablation working pressure boosting pipeline (the fourth pipeline L4), a gaseous working medium output pipeline (the fifth pipeline L5), a replacement and rewarming pipeline (the sixth pipeline L6), a return gas recovery pipeline (the seventh pipeline L7), a system flow monitoring and recovery condition control pipeline (the eighth pipeline L8), and a vacuum degree creation pipeline (the ninth pipeline L9).

[0163] ① It includes the conveying device of the above embodiment, where the liquid refrigerant output pipeline (the first pipeline L1) is used to transport a liquid working medium and includes:

[0164] a liquid refrigerant pipe (L1-1); a liquid refrigerant output valve (L1-2); a safety relief valve (L1-3); and a liquid refrigerant output pipeline pressure transmitter (L1-4) and a temperature sensor (L1-5) participating in closed-loop control, which are used to monitor the state parameters of the fluid working medium entering the flexible cryoprobe; a liquid refrigerant output check valve (L1-6) to prevent backflow.

[0165] ② The internal flow of the precooling fluid recovery pipeline (i.e., the second pipeline (L2)) is a gaseous working medium. One end of the second pipeline (L2) is connected to the first pipeline (L1), and the other end is connected to the eighth pipeline (L8) and finally transported into the second pressure vessel (C2).

[0166] The second pipeline (L2) is used to transport the fluid working medium to the system flow monitoring and recovery condition control pipeline (L8) during the precooling process in the cryoablation procedure and includes:

[0167] a precooling fluid recovery pipe (L2-1); a precooling fluid recovery solenoid valve (L2-2), which is opened during the cryoablation procedure and closed after reaching the precooling temperature threshold range; a precooling fluid recovery check valve (L2-3) to prevent backflow.

[0168] ③ The cryoablation working pressure reduction pipeline (i.e., the third pipeline (L3)), which is connected to the first pressure vessel (C1) and is used to release the pressure of the liquid working medium Dewar pressure vessel (C1). It includes:

[0169] Cryoablation working pressure decompression pipe (L3-1); Cryoablation working pressure decompression solenoid valve (L3-2), which opens when the pressure of the liquid working medium in the liquid nitrogen working medium pressure vessel (C1) is higher than the release pressure threshold and closes when it is lower than the release pressure threshold.

[0170] ④ The cryoablation working pressure boosting pipeline (i.e., the fourth pipeline (L4), which connects the first pressure vessel (C1) and the second pressure vessel (C2) and is used to input the gaseous working medium in the gaseous working medium pressure vessel (C2) into the liquid working medium Dewar pressure vessel (C1) for boosting, includes:

[0171] Cryoablation working pressure boosting pipe (L4-1); Cryoablation working pressure boosting solenoid valve (L4-2), which opens when the pressure of the liquid working medium in the liquid nitrogen working medium pressure vessel (C1) is lower than the boosting pressure threshold and closes when it is higher than the boosting pressure threshold. The cryoablation working pressure control element (L4-3) participates in closed-loop control and is used to adjust the cryoablation working pressure.

[0172] ⑤ The gaseous working medium output pipeline (i.e., the fifth pipeline (L5) connects the third pressure vessel (C3) and the second pressure vessel (C2) and is used to input the gaseous working medium in the phase change pressure vessel (C3) into the gaseous working medium pressure vessel (C2) for boosting, includes:

[0173] Gaseous working medium output pipe (L5-1), pressure monitoring element of the phase change pressure vessel: phase change pressure transmitter (L5-2); phase change vessel pressure relief solenoid valve (L5-3), which opens to empty the gaseous working medium in the phase change pressure vessel (C3) or create a pressure difference between the liquid working medium pressure vessel (C1) and the phase change pressure vessel (C3) to enable the liquid working medium to enter the phase change pressure vessel (C3) from the liquid working medium pressure vessel (C1) and closes when there is liquid working medium entering; the gaseous working medium output solenoid valve (L5-4) opens when the pressure threshold of the phase change pressure transmitter (L5-2) is higher than the gaseous working medium output pressure threshold and closes otherwise; the gaseous working medium output pressure control element (L5-5) is used to adjust the pressure in the gaseous working medium pressure vessel (C2).

[0174] ⑥ The replacement and rewarming pipeline (i.e., the sixth pipeline L6) connects the second pressure vessel (C2) and the cryoablation device (CP) and is used to selectively heat the gaseous working medium in the gaseous working medium pressure vessel (C2) and transport it to the cryoablation device (CP) during the replacement process in the cryoablation procedure, includes:

[0175] Displacement and rewarming tube (L6-1); displacement and rewarming solenoid valve (L6-2), which is opened during the displacement process in the cryoablation procedure and closed after the displacement procedure, for displacing the air inside the cryoablation device; when opened during the rewarming process in the cryoablation procedure, the displacement and rewarming heat exchanger (L6-3) is started simultaneously, for heating the gaseous working medium in the displacement and rewarming tube (L6-1) to the threshold temperature. At the same time, the rewarming temperature sensor (L6-4) participates in this rewarming process, cooperating to adjust the heating power of the displacement and rewarming heat exchanger (L6-2), so that the gaseous working medium in the displacement and rewarming tube (L6-1) reaches the threshold temperature; displacement and rewarming check valve (L6-5) to prevent backflow.

[0176] ⑦ The return air recovery pipeline (i.e., one end of the seventh pipeline (L7) is connected to the cryoablation device (CP), and the other end is connected to the eighth pipeline (L8)), for transporting the return air generated during the freezing process in the cryoablation procedure to the system flow monitoring and recovery condition control pipeline (L8), including:

[0177] Return air recovery tube (L7-1); return air recovery pipeline check valve (L7-2) to prevent backflow.

[0178] ⑧ The system flow monitoring and recovery condition control pipeline (i.e., one end of the eighth pipeline (L8) is simultaneously connected to the seventh pipeline (L7) and the second pipeline (L2), and the other end is connected to the second pressure vessel (C2)), for heating the fluid working medium flowing in from the precooling fluid recovery pipeline (L2) during the precooling process in the cryoablation procedure and then pumping it to the gaseous working medium pressure vessel (C2). Also, during the freezing process in the cryoablation procedure, heating the fluid working medium flowing in from the return air recovery pipeline (L7), measuring the flow rate with a flowmeter, and then pumping it to the gaseous working medium pressure vessel (C2); the measured flow rate participates in the pressure control of the system. It includes:

[0179] System flow monitoring and recovery condition control pipe (L8-1); System flow monitoring and recovery condition control heat exchanger (L8-2), which is used to heat the pre-cooling process in the cryoablation procedure, heat the fluid flowing in from the pre-cooled fluid recovery pipe (L2) and make it reach the threshold temperature; and the fluid flowing in from the return gas recovery pipe (L7) during the freezing process in the cryoablation procedure and make it reach the threshold temperature; The system flow monitoring and recovery condition control temperature sensor (L8-3) participates in the closed-loop control and is used to cooperate with adjusting the heating power of the system flow monitoring and recovery condition control heat exchanger (L8-2) to make the fluid in the system flow monitoring and recovery condition control pipe (L8-1) reach the threshold temperature; If the fluid working medium cannot reach the threshold temperature after heating, the gas working medium recovery release valve (L8-7) opens to discharge the fluid working medium to the atmosphere; The system flow monitoring and recovery condition control flowmeter (L8-4) is mainly used to monitor the fluid flow rate flowing into the system flow monitoring and recovery condition control pipe (L8-1) from the return gas recovery pipe (L7-1) during the freezing process in the cryoablation procedure, participates in the closed-loop control, is used to predict the cryoablation effect, and cooperate with the pressure adjustment to make the cryoablation effect meet the expectations. The system flow monitoring and recovery condition control extraction booster pump (L8-5) adjusts the suction power in cooperation with the adjustment of the working pressure to further promote the smooth return of the gas and make the cryoablation effect reach the expectation. The system flow monitoring and recovery condition control check valve (L8-6) prevents backflow.

[0180] ⑨ The vacuum degree creation pipeline (i.e., the ninth pipeline L9) connects the cryoablation device (CP) and the vacuum device (L9-3) and is used to create a high vacuum degree for the cryoablation device (CP) to achieve a good vacuum insulation effect, including:

[0181] The vacuum degree creation pipe (L9-1); The vacuum gauge (L9-2) is used to monitor whether the vacuum degree reaches the threshold requirement; The vacuum degree creation pump group is used to create a high vacuum degree so that the flexible cryoprobe has a good vacuum insulation effect.

[0182] 3) The cryoablation device (CP) including a temperature measurement sensor and a heating element.

[0183] ① The cryoablation device (CP) can be a flexible cryoprobe, etc., which is used to perform the cryoablation procedure on the lesion after entering the human body through the natural cavity, including:

[0184] The structure for enhancing the performance of interventional cryoablation; The distal thermocouple (CP1) of the cryoablation device is used to monitor the temperature inside the cryoprobe and participates in the closed-loop control; The distal nichrome wire of the cryoablation device is used for the rewarming process in the cryoablation procedure.

[0185] The following combines Figures 10 to 16 to illustrate the working process of the cryoablation system

[0186] The steps in the figure are shown in sequence according to the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise clearly stated in this document, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the figure may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0187] 1) The system starts and initializes, reads the control threshold parameters stored in the memory; meanwhile, obtains the data of the system sensors.

[0188] 2) First, judge the liquid level in the liquid working medium Dewar pressure vessel (C1). LLC1-2_Lower Limit is the low liquid level warning threshold of this vessel, and execute the judgment program:

[0189] If the current liquid level LLC1-2_CL of the liquid working medium level sensor (C1-2) is less than LLC1-2_Lower Limit, the system considers that this liquid level cannot maintain the current cryoablation procedure, that is, LLC1-2_Lower Limit is the volume of liquid nitrogen required for a cryoablation procedure with redundancy. Thereafter, execute the liquid nitrogen replenishment program. When LLC1-2_CL ≥ LLC1-2_Upper Limit; the liquid nitrogen filling is completed.

[0190] If the current liquid level LLC1-2_CL of the liquid working medium level sensor (C1-2) is greater than or equal to LLC1-2_Lower Limit, the system considers that the current cryoablation procedure can be executed.

[0191] 3) Judge the pressure in the liquid working medium Dewar pressure vessel (C1). PC1_IWP is the pressure threshold at the initialization of this pressure vessel; execute the judgment program:

[0192] If the current pressure PC1-1_CP of the liquid working medium pressure sensor (C1-1) is less than or equal to PC1_IWP, the system considers that the pressure in the pressure vessel meets the pressure requirements at the initialization and can continue to execute the subsequent procedures; PC1_IWP is the initialization pressure of the liquid working medium Dewar pressure vessel (C1) before the cryoablation procedure. This pressure is usually the pressure when the liquid working medium Dewar pressure vessel (C1) is not in use and is usually static. Note: The initialization pressure PC1_IWP of the pressure vessel < the working pressure PC1_WP of the liquid working medium Dewar pressure vessel.

[0193] If the current pressure PC1-1_CP of the liquid working medium pressure sensor (C1-1) > PC1_IWP, execute the pressure relief procedure, open the cryoablation working pressure reducing solenoid valve (L3-2) to relieve the pressure until PC1-1_CP ≤ PC1_IWP.

[0194] 4) Determine the pressure inside the gaseous working medium pressure vessel (C2). PC2_IWP is the pressure threshold at the initialization of this pressure vessel; execute the determination procedure:

[0195] If the current pressure PC2-1_CP of the gaseous working medium pressure sensor (C2-1) ≤ PC2_IWP, the system considers that the pressure inside the pressure vessel meets the pressure requirements at the initialization and can continue to execute the subsequent procedures; PC2_IWP is the initialization pressure of the gaseous working medium pressure vessel (C2) before the cryoablation procedure. This pressure is usually the gaseous working medium stored inside the gaseous working medium pressure vessel (C2) after the last cryoablation procedure; since the gas in the gaseous working medium pressure vessel (C2) is the gas from the recovery pre-cooling process and the cryoablation process and will output gas during the rewarming process, in order to ensure the normal recovery during the pre-cooling and cryoablation procedures of the next operation, therefore, PC2_IWP of this pressure < the working pressure PC2_WP of the gaseous working medium pressure vessel (C2).

[0196] If the current pressure PC2-1_CP of the gaseous working medium pressure sensor (C2-1) > PC2_IWP, execute the pressure relief procedure, open the gaseous working medium pressure relief valve (C2-2) to relieve the pressure until PC2-1_CP ≤ PC2_IWP.

[0197] 5) Determine the pressure inside the phase change pressure vessel (C3). PC3_IWP is the pressure threshold at the initialization of this pressure vessel; execute the determination procedure:

[0198] If the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) ≤ PC3_IWP; the system considers that the pressure inside the pressure vessel meets the pressure requirements at the initialization and can continue to execute the subsequent procedures. This pressure PC3_IWP < the working pressure PC3_WP inside the phase change pressure vessel (C3).

[0199] If the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) > PC3_IWP, execute the pressure relief procedure, open the phase change vessel pressure relief solenoid valve (L5-3) to relieve the pressure until PL5-2_CP ≤ PC3_IWP.

[0200] 6) Determine whether the current pressure of the phase change pressure transmitter (L5-2), PL5-2_CP > PC2-1_CP, the current pressure of the gaseous working medium pressure sensor (C2-1). If so, open the gaseous working medium output solenoid valve (L5-4) and set the output pressure of the gaseous working medium output pressure control element (L5-5): PL5-5_SP_OUT > PC2-1_CP. At this time, the gaseous working medium in the phase change pressure vessel (C3) enters the gaseous working medium pressure vessel (C2) until PL5-2_CP - PC2-1_CP < △P0, that is, the pressure in the current phase change pressure vessel (C3) is equal to the pressure in the gaseous working medium pressure vessel (C2), then close the gaseous working medium output solenoid valve (L5-4) and turn off the output of the gaseous working medium output pressure control element (L5-5). By using the gaseous working medium in the phase change pressure vessel (C3), the utilization rate is improved.

[0201] 7-1) Open the liquid refrigerant output valve (L1-2). First, enter the pre-cooling program of the cryoablation process, and all components in the pre-cooled fluid recovery pipeline (L2) and the system flow monitoring and recovery condition control pipeline (L8) enter the working state. Open the pre-cooled fluid recovery solenoid valve (L2-2), and the system flow monitoring and recovery condition control heat exchanger (L8-2) starts.

[0202] The system flow monitoring and recovery condition control flowmeter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) have restrictions on the fluid temperature. Therefore, the system sets temperature thresholds: TL8-2_ET_Lower Limit: the first heat exchange temperature of the system flow monitoring and recovery condition control heat exchanger and TL8-2_ET_Upper Limit: the second heat exchange temperature of the system flow monitoring and recovery condition control heat exchanger, which respectively correspond to the lower limit and the upper limit of the temperature range.

[0203] If: the current fluid temperature collected by the system flow monitoring and recovery condition control temperature sensor (L8-3):

[0204] TL8-3_CT ≥ TL8-2_ET_Lower Limit && TL8-3_CT ≤ TL8-2_ET_Upper Limit; the gas working medium recovery release valve (L8-7) closes, and the fluid enters the gaseous working medium pressure vessel (C2) through the system flow monitoring and recovery condition control flowmeter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) for pressurization.

[0205] If: TL8-3_CT < TL8-2_ET_Lower Limit || TL8-3_CT > TL8-2_ET_Upper Limit; the gas working medium recovery and release valve (L8-7) opens. The fuzzy self-tuning PID temperature control algorithm is called to make the temperature satisfy TL8-3_CT ≥ TL8-2_ET_Lower Limit && TL8-3_CT ≤ TL8-2_ET_Upper Limit, and then the gas working medium recovery and release valve (L8-7) is closed. The fluid passes through the flowmeter for system flow monitoring and recovery condition control (L8-4) and the extraction booster pump for system flow monitoring and recovery condition control (L8-5) and enters the gaseous working medium pressure vessel (C2) for pressurization.

[0206] The above steps are cyclically pressurized until the event occurs: the current temperature TL1-5_CT collected by the liquid refrigerant output pipeline temperature sensor (L1-5) - the pre-cooling threshold temperature of TL1-5_PT < △T0 || (or) the current pressure of the gaseous working medium pressure sensor (C2-1) of the second pressurization closing pressure PC2_PB_CV - PC2-1_CP of the gaseous working medium pressure vessel (C2) < △P0.

[0207] If in the above OR logic, TL1-5_CT - TL1-5_PT < △T0 occurs, it means the pre-cooling process is over. The liquid refrigerant output valve (L1-2) is closed, the system timer is started, and the time interval is △t. After the liquid refrigerant output valve (L1-2) is closed, the residual fluid in the liquid refrigerant output pipeline (L1) and the pre-cooling fluid recovery pipeline (L2) enters the gaseous working medium pressure vessel (C2); then the extraction booster pump for system flow monitoring and recovery condition control (L8-5) is closed.

[0208] If in the above OR logic, TL1-5_CT - TL1-5_PT < △T0 is false, then the event PC2_PB_CV - PC2-1_CP < △P0 must have occurred; the pressure in the gaseous working medium pressure vessel (C2) reaches the pressurization requirement; therefore, the extraction booster pump for system flow monitoring and recovery condition control (L8-5) is closed; the gas working medium recovery and release valve (L8-7) is opened to discharge the fluid in the pipeline into the atmosphere until the event TL1-5_CT - TL1-5_PT < △T0 occurs and the pre-cooling condition is reached;

[0209] Then the liquid refrigerant output valve (L1-2) is closed, the system timer is started, and the time interval is △t. After the liquid refrigerant output valve (L1-2) is closed, the residual fluid in the liquid refrigerant output pipeline (L1) and the pre-cooling fluid recovery pipeline (L2) enters the gaseous working medium pressure vessel (C2); then the extraction booster pump for system flow monitoring and recovery condition control (L8-5) is closed.

[0210] Next, enter the pressure condition judgment of the gaseous working medium pressure vessel (C2). When the current pressure of the gaseous working medium pressure sensor (C2-1) < △P0, open the gaseous working medium pressure relief valve (C2-2) for pressure relief; until the current pressure of the gaseous working medium pressure sensor (C2-1) PC2-1_CP - PC2_RP_CV < △P0, close the gaseous working medium pressure relief valve (C2-2).

[0211] 7-2) Judge that the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) ≥ PC1-1_CP, the current pressure PC1-1_CP of the liquid working medium pressure sensor (C1-1); open the phase change container pressure relief solenoid valve (L5-3). When the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) - atm < △P0 && the current liquid level value LLC3-4_CL of the liquid level sensor (C3-4) of the phase change pressure vessel (C3) < LLC3-4_CV - LLC3-4_CL, the first liquid level closing threshold of the liquid level sensor (C3-4); close the phase change container pressure relief solenoid valve (L5-3) and start the phase change heating device (C3-2) for heating.

[0212] If it is judged that the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) < PC1-1_CP && the current liquid level value LLC3-4_CL of the liquid level sensor (C3-4) of the phase change pressure vessel (C3) < LLC3-4_Lower Limit, the first low liquid level threshold of the liquid level sensor (C3-4); open the phase change container pressure relief solenoid valve (L5-3). When the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) - atm < △P0 && the current liquid level value LLC3-4_CL of the liquid level sensor (C3-4) of the phase change pressure vessel (C3) < LLC3-4_CV - LLC3-4_CL, the first liquid level closing threshold of the liquid level sensor (C3-4); close the phase change container pressure relief solenoid valve (L5-3) and start the phase change heating device (C3-2) for heating.

[0213] 7-2-2) If it is judged that the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) < PC1-1_CP && the current liquid level value LLC3-4_CL of the liquid level sensor (C3-4) of the phase change pressure vessel (C3) ≥ LLC3-4_Lower Limit, the first low liquid level threshold of the liquid level sensor (C3-4), start the phase change heating device (C3-2) for heating.

[0214] After the phase change heating device (C3-2) is started, if the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) > the third supercharging lower limit threshold PC3_PB_Lower Limit; and the current temperature TC3-5_CT collected by the temperature sensor (C3-5) < TC3-5_Upper Limit: the first high temperature threshold of the temperature sensor (C3-5); the phase change heating device (C3-2) continues to heat.

[0215] Until: the currently collected temperature TC3-5_CT ≥ the first high temperature threshold of the temperature sensor (C3-5) TC3-5_Upper Limit or the current pressure of the variable pressure transmitter (L5-2) of the third supercharging closing threshold PC3_PB_CV - PL5-2_CP < △P0; the variable heating device (C3-2) stops heating.

[0216] If the current pressure PL5-2_CP of the phase change pressure transmitter (L5-2) ≤ the third supercharging lower limit threshold PC3_PB_Lower Limit and the current temperature TC3-5_CT collected by the temperature sensor (C3-5) ≥ the first high temperature threshold of the temperature sensor (C3-5) TC3-5_Upper Limit, stop heating, this supercharging is invalid, and the supercharging process is executed again. Otherwise, continue heating until one of the above judgment conditions appears.

[0217] When the device meets the condition that the current temperature TC3-5_CT collected by the temperature sensor (C3-5) is ≥ TC3-5_UpperLimit, the first high-temperature threshold of the temperature sensor (C3-5), or the current pressure of the variable pressure transmitter (L5-2) of the third supercharging shutdown threshold PC3_PB_CV-PL5-2_CP < △P0, the output program is executed. The gaseous working medium output solenoid valve (L5-4) is opened, and the output pressure of the gaseous working medium output pressure control element (L5-5) is set: PL5-5_SP_OUT > PC2-1_CP; at this time, the gaseous working medium in the phase change pressure vessel (C3) enters the gaseous working medium pressure vessel (C2); until the current pressure of the variable pressure transmitter (L5-2) PL5-2_CP - PC3_PB_OV, the third supercharging start threshold < △P0 || (or) the current pressure of the variable pressure transmitter (L5-2) PL5-2_CP - PC2-1_CP, the current pressure of the gaseous working medium pressure sensor (C2-1) < △P0 <The limit here is determined by the controller. When the gaseous working medium pressure vessel (C2) is gradually supercharged, PC2-1_CP will gradually increase. However, the requirement of the pressure controller is that the upstream pressure should be greater than the downstream pressure, so this logic should be available here> || (or) the current pressure of the gaseous working medium pressure sensor (C2-1) of the second supercharging shutdown pressure PC2_PB_CV - PC2-1_CP of the gaseous working medium pressure vessel (C2) < △P0, the gaseous working medium output solenoid valve (L5-4) is closed, and the gaseous working medium output pressure control element (L5-5) is shut off.

[0218] The above supercharging process may be in multiple cycles until the event: the current pressure of the gaseous working medium pressure sensor (C2-1) of the second supercharging shutdown pressure PC2_PB_CV - PC2-1_CP of the gaseous working medium pressure vessel (C2) < △P0 occurs, indicating that the initialization supercharging process of the gaseous working medium pressure vessel (C2) ends.

[0219] To prevent the pressure in the phase change pressure vessel C3 from being at a high level when stopped, a pressure relief judgment is introduced: when the current pressure of the phase change pressure transmitter (L5-2) PL5-2_CP - PC3_RP_OV, the third pressure reduction start threshold of the phase change pressure vessel (C3) < △P0, the phase change vessel pressure relief solenoid valve (L5-3) is opened. When the current pressure of the variable pressure transmitter (L5-2) PL5-2_CP - PC3_RP_CV, the third pressure reduction shutdown threshold of the phase change pressure vessel (C3) < △P0, the phase change vessel pressure relief solenoid valve (L5-3) is closed. To prevent the pressure in C3 from being too high.

[0220] Next, enter the pressure condition judgment of the gaseous working medium pressure vessel (C2). When the current pressure of the gaseous working medium pressure sensor (C2-1) is less than ΔP0 at the second pressure reduction opening threshold PC2_RP_OV - PC2-1_CP, open the gaseous working medium pressure relief valve (C2-2) for pressure relief; until the current pressure of the gaseous working medium pressure sensor (C2-1) is less than ΔP0 at the second pressure reduction closing threshold PC2-1_CP - PC2_RP_CV, close the gaseous working medium pressure relief valve (C2-2).

[0221] 8) After the above process, the gaseous working medium pressure vessel (C2) already meets its working pressure requirement: PC2_WP; the phase change pressure vessel (C3) also meets its working pressure requirement; PC3_WP; the liquid refrigerant output pipeline (L1) has been sufficiently precooled.

[0222] Therefore, it meets the requirements of the subsequent cryoablation procedure. Detect or connect the system consumables, and until the system connects the consumables, enter the steps of building pressure in the liquid working medium Dewar pressure vessel (C1) and replacing the gas inside the consumables.

[0223] 9) Open the replacement and rewarming solenoid valve (L6-2) to enter the replacement procedure; the purpose of replacement is to replace the air and moisture inside the pipeline of the consumables with the gaseous working medium in the gaseous working medium pressure vessel (C2) before the freezing process. The replacement and rewarming heat exchanger (L6-3) starts. After passing through the fuzzy self-tuning PID temperature control algorithm, the temperature of the replacement gas is raised to room temperature, that is, it meets TL6-4_CT – room temperature < ΔT0; the gas enters the system flow monitoring and recovery condition control pipeline (L8) after passing through the return gas recovery pipeline (L7). Then, it enters the gaseous working medium pressure vessel (C2) through a recovery process similar to the precooling process as follows:

[0224] The system flow monitoring and recovery condition control flowmeter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) have restrictions on the fluid temperature. Therefore, the system sets temperature thresholds: TL8-2_ET_Lower Limit: the first heat exchange temperature of the system flow monitoring and recovery condition control heat exchanger and TL8-2_ET_Upper Limit: the second heat exchange temperature of the system flow monitoring and recovery condition control heat exchanger; they correspond to the lower limit and the upper limit of the temperature range respectively.

[0225] If: the current fluid temperature collected by the system flow monitoring and recovery condition control temperature sensor (L8-3):

[0226] TL8 - 3_CT ≥ TL8 - 2_ET_Lower Limit && TL8 - 3_CT ≤ TL8 - 2_ET_Upper Limit; The gas working medium recovery and release valve (L8 - 7) is closed, and the fluid passes through the system flow monitoring and recovery condition control flowmeter (L8 - 4) and the system flow monitoring and recovery condition control extraction booster pump (L8 - 5) and enters the gaseous working medium pressure vessel (C2) for pressurization.

[0227] If: TL8 - 3_CT < TL8 - 2_ET_Lower Limit || TL8 - 3_CT > TL8 - 2_ET_UpperLimit; The gas working medium recovery and release valve (L8 - 7) is opened. The fuzzy self - tuning PID temperature control algorithm is called to make the temperature satisfy TL8 - 3_CT ≥ TL8 - 2_ET_Lower Limit && TL8 - 3_CT ≤ TL8 - 2_ET_Upper Limit, and then the gas working medium recovery and release valve (L8 - 7) is closed. The fluid passes through the system flow monitoring and recovery condition control flowmeter (L8 - 4) and the system flow monitoring and recovery condition control extraction booster pump (L8 - 5) and enters the gaseous working medium pressure vessel (C2) for pressurization.

[0228] This replacement process outputs from the gaseous working medium pressure vessel (C2) and then returns to the gaseous working medium pressure vessel (C2); This process will not cause a drastic change in pressure, so pressure judgment is not made for this process. In addition, the entire replacement process lasts for Δt1.

[0229] The replacement process ends, and Probe_ZH_Flag is sent.

[0230] 10) Raise the liquid working medium Dewar pressure vessel (C1) to the working pressure; Open the cryoablation working pressure boosting solenoid valve (L4 - 2); Set the output pressure PL4 - 3_SP_OUT of the cryoablation working pressure control element (L4 - 3) > the first boosting initialization closing threshold PC1_PB_CV; Thus, the gaseous working medium pressure vessel (C2) pressurizes the liquid working medium Dewar pressure vessel (C1) through the cryoablation working pressure boosting pipeline (L4) until: The first boosting initialization closing threshold PC1_PB_CV - PC1 - 1_CP liquid working medium pressure sensor (C1 - 1)

[0231] The currently collected pressure < ΔP0; It means that the pressurization of the liquid working medium Dewar pressure vessel (C1) is completed. Close the cryoablation working pressure boosting solenoid valve (L4 - 2) and turn off the cryoablation working pressure control element (L4 - 3).

[0232] The pressure building before ablation of the liquid working medium Dewar pressure vessel (C1) ends, and PC1_PreCyro_Flag is sent.

[0233] 11-1) When the event: Probe_ZH_Flag == 1 && PC1_PreCyro_Flag == 1 occurs, cryoablation is ready. Wait for the event: Probe_Cyro_Star == 1; Set the cryoablation delay duration: Δt2; Open the liquid cryogen output valve (L1-2); Start the cryoablation timer timer2; When the cryoablation duration is Δt2, the cryo process of this cycle ends, and the cryo cycle count Cryo_Cycle++ during the cryoablation process; Then close the liquid cryogen output valve (L1-2). The cryo process of this cryoablation cycle ends.

[0234] 11-2) The rewarming process of the cryoablation cycle begins. The replacement and rewarming heat exchanger (L6-3) is started. After passing through the fuzzy self-tuning PID temperature control algorithm, the fourth current temperature of the rewarming gas satisfies: TL6-4_CT < TL6-3_RW_UpperLimit && TL6-3_RW_LowerLimit < TL6-4_CT. Then, start the rewarming timer timer3. When the rewarming duration during cryoablation is Δt3, the reset cycle count Cryo_Cycle++ during the cryoablation process; Then close the solenoid valve L6-2; Shut down the replacement and rewarming heat exchanger (L6-3).

[0235] After one cryo and rewarming cycle, judge the event:

[0236] Cryo_Cycle == Cryo_Set && ReWarm_Cycle == RW_Set

[0237] When it occurs, it indicates the end of the cryo cycle, otherwise continue to perform the cryoablation surgery.

[0238] 11-3) During the above process, the recovery process is executed. After passing through the return gas recovery pipeline (L7), it enters the system flow monitoring and recovery condition control pipeline (L8).

[0239] Then, enter the gaseous working medium pressure vessel (C2) using a recovery process similar to the precooling process, as follows:

[0240] The system flow monitoring and recovery condition control flowmeter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) have restrictions on the fluid temperature. Therefore, the system sets temperature thresholds: TL8-2_ET_LowerLimit: The first heat exchange temperature of the system flow monitoring and recovery condition control heat exchanger and TL8-2_ET_UpperLimit: The second heat exchange temperature of the system flow monitoring and recovery condition control heat exchanger; respectively

[0241] corresponds to the lower limit and the upper limit of the temperature range.

[0242] If: the current fluid temperature collected by the system flow monitoring and recovery condition control temperature sensor (L8-3): TL8-3_CT ≥ TL8-2_ET_Lower Limit && TL8-3_CT ≤ TL8-2_ET_Upper Limit; the gas working medium recovery release valve (L8-7) is closed, and the fluid passes through the system flow monitoring and recovery condition control flowmeter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) and enters the gaseous working medium pressure vessel (C2) for pressurization.

[0243] If: TL8-3_CT < TL8-2_ET_Lower Limit || TL8-3_CT > TL8-2_ET_Upper Limit; the gas working medium recovery release valve (L8-7) is opened.

[0244] Call the fuzzy self-tuning PID temperature control algorithm to make the temperature satisfy TL8-3_CT ≥ TL8-2_ET_Lower Limit && TL8-3_CT ≤ TL8-2_ET_Upper Limit, then close the gas working medium recovery release valve (L8-7), and the fluid passes through the system flow monitoring and recovery condition control flowmeter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) and enters the gaseous working medium pressure vessel (C2) for pressurization. When the event: PC2_PB_CV - PC2-1_CP < △P0 occurs, the recovered fluid does not enter the gaseous working medium pressure vessel (C2) and is discharged to the atmosphere from the bypass; when the event:

[0245] Cryo_Cycle == Cryo_Set && ReWarm_Cycle == RW_Set

[0246] occurs, it indicates the end of the cryogenic cycle, otherwise continue to execute.

[0247] When cryoablation starts, the vacuum device (L9-3) starts to work, and the vacuum degree is the set Vaccum; until the cryoablation program ends.

[0248] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope described in this specification. When the technical features in different embodiments are shown in the same drawing, it can be regarded that the drawing also discloses the combination examples of the various embodiments involved at the same time.

[0249] The embodiments described above merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patented application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A method for starting a cryoablation system, characterized in that, The cryoablation system includes: A cryoablation device; A first pressure vessel for storing a liquid working medium and connected to the cryoablation device through a first pipeline; A second pressure vessel for storing a gaseous working medium; A third pressure vessel disposed within the first pressure vessel for transforming the liquid working medium into a gaseous working medium; The startup method includes: Pre-cooling the first pipeline and the cryoablation device with the liquid working medium in the first pressure vessel, and simultaneously recovering the refluxed working medium in the first pipeline and the cryoablation device using the second pressure vessel; After pre-cooling, outputting gaseous working medium from the third pressure vessel to the second pressure vessel and, via the second pressure vessel, to the first pressure vessel to adjust the pressures of the first pressure vessel and the second pressure vessel and build pressure in the second pressure vessel; After building pressure, replacing the interior of the cryoablation device with the gaseous working medium in the second pressure vessel; After replacement, outputting liquid working medium from the first pressure vessel to the cryoablation device to start cryoablation.

2. The starting method of the cryoablation system according to claim 1, wherein, The first pipeline has a double-layer structure inside and outside. When meeting the first preset condition, the liquid working medium outputs two paths through the inner layer of the first pipeline. The first path passes through the cryoablation device and reaches the second pressure vessel, and the second path passes through the outer layer of the first pipeline and reaches the second pressure vessel; When meeting the second preset condition, the pre-cooling ends and the output of the first pipeline stops.

3. The starting method of the cryoablation system according to claim 2, characterized in that, The first preset condition is that the current liquid level of the first pressure vessel is within a preset range.

4. The starting method of the cryoablation system according to claim 2, wherein The second preset condition is that the first current temperature of the inner layer of the first pipeline is within a preset range.

5. The starting method of the cryoablation system according to claim 1, characterized in that, During pre-cooling, a booster pump is used to increase the second current pressure of the second pressure vessel to be within a second preset pressure range, and the booster pump delays closing after pre-cooling ends.

6. The startup method of the cryoablation system according to claim 5, characterized in that After pre-cooling, obtain the third current pressure and the third current liquid level of the third pressure vessel. If the third current pressure is lower than the first current pressure and the third current liquid level is lower than the first liquid level preset value, the third pressure vessel accepts the liquid working medium.

7. The starting method of the cryoablation system according to claim 6, characterized in that, Before the third pressure vessel transports gaseous working medium to the second pressure vessel, it also includes pre-boosting the third pressure vessel; The steps of pre-boosting include obtaining the third current liquid level and the third current pressure of the third pressure vessel. After the third current liquid level and the third current pressure meet the preset conditions, the third pressure vessel is heated to transform the liquid working medium inside itself into a gaseous working medium until the pre-boosting completion condition is met.

8. The starting method of the cryoablation system according to claim 7, characterized in that, After the pre-boosting is completed, start building pressure in the second pressure vessel. The condition for the second pressure vessel to complete building pressure is that the second current pressure is within a third pressure preset range.

9. The starting method of the cryoablation system according to claim 8, wherein After the second pressure vessel completes building pressure, build pressure in the first pressure vessel. The condition for the first pressure vessel to complete building pressure is that the first current pressure is within a first pressure preset range.

10. The starting method of the cryoablation system according to claim 1, wherein, During the replacement process, a heat exchanger and a booster pump are used to heat and boost the refluxed working medium.

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