CN114521953A

CN114521953A - Working medium precooling system for cryoablation

Info

Publication number: CN114521953A
Application number: CN202111654102.1A
Authority: CN
Inventors: 徐宏; 胡艳艳; 王晓钫; 项腾; 许金苗; 尤玲丽
Original assignee: Hangzhou Kunbo Biotechnology Co Ltd
Current assignee: Hangzhou Kunbo Biotechnology Co Ltd
Priority date: 2021-06-30
Filing date: 2021-12-30
Publication date: 2022-05-24
Also published as: CN114526444A; CN114636102B; CN218075189U; CN218494750U; CN114376711A; CN114504372B; CN114526444B; CN218420016U; CN114526441B; CN114699160A; CN114711944A; CN114504372A; CN217503347U; CN114719183A; CN114636102A; CN114526441A; CN217960278U

Abstract

The application provides a working medium precooling system for cryoablation, which comprises a first pressure container, a second pressure container, a first pipeline and a second pipeline, wherein the first pressure container is used for storing liquid-phase frozen working medium; the second pressure container is used for storing gaseous working media; the second pipeline is connected between the first pressure container and the second pressure container; the first pipeline is connected between the first pressure container and the cryoablation device and used for conveying liquid-phase frozen working medium to the cryoablation device in the ablation process, the first pipeline is of an inner-outer double-layer structure, and when precooling is conducted, the liquid-phase cold working medium sequentially flows through the inner layer of the first pipeline, the outer layer of the first pipeline and the second pipeline from the first pressure container until reaching the second pressure container. The gasification of the working medium caused by temperature difference can be effectively reduced, and the air blockage is eliminated. And the working medium on the outer layer is used as an isolation layer to limit the heat exchange between the working medium on the inner layer and air, so that the time of cryoablation is prolonged. And a corresponding pipeline for recovering working media is additionally arranged, so that the environment is protected and the energy is saved.

Description

Working medium precooling system for cryoablation

Technical Field

The application relates to the technical field of medical instruments, in particular to a working medium precooling system for cryoablation.

Background

In the course of combating cancer, chemotherapy, radiotherapy and surgical treatment have become three common approaches to the treatment of malignant tumors, and tumor immunotherapy is also under intense research. Minimally invasive treatment of tumors is an important supplement to surgical treatment, wherein physical ablation is increasingly applied to various treatment means of tumors, including microwave, freezing, laser, radio frequency, high-power focused ultrasound and the like, so as to necrose cancer tissues.

In the early 20 th century, the rapid development of industry and science and technology, and the refrigeration substances such as concentrated oxygen, liquid oxygen, concentrated nitrogen, liquid nitrogen, dry ice and the like are successfully prepared in the progress of the industrial science and technology, so that the step of commercial development is accelerated, a new place of medical refrigeration is opened up, and the application of the low-temperature technology in medical treatment is promoted. Various refrigeration technologies have been developed in the continuing progress of low-temperature science, and gas throttling technology, phase-change cooling, vapor pressure absorption refrigeration, thermoelectric refrigeration and the like are main refrigeration schemes used in modern medicine.

The existing phase-change cooling method by using liquid refrigerant is easy to cause 'air blockage' in a pipeline or cooling ablation equipment, finally leads to the failure of cryoablation, and seriously influences the operation safety.

Disclosure of Invention

The application discloses a working medium precooling system for cryoablation, which can reduce the occurrence of air blockage.

The application provides a working medium precooling system for cryoablation, includes:

the first pressure container is used for storing liquid-phase freezing working medium;

a second pressure vessel; the second pressure container is used for storing gaseous working media;

a second conduit connected between the first pressure vessel and the second pressure vessel;

the first pipeline is connected between the first pressure container and the cryoablation equipment and used for conveying liquid-phase frozen working medium to the cryoablation equipment in the ablation process, the first pipeline is of an inner-outer double-layer structure, and when precooling is conducted, the liquid-phase cold working medium flows through the inner layer of the first pipeline, the outer layer of the first pipeline and the second pipeline in sequence from the first pressure container until the second pressure container.

Several alternatives are provided below, but not as an additional limitation to the above general solution, but merely as a further addition or preference, each alternative being combinable individually for the above general solution or among several alternatives without technical or logical contradictions.

Optionally, one end of the first conduit adjacent to the first pressure vessel is a first end, and one end adjacent to the cryoablation apparatus is a second end;

the inner layer of the first conduit is communicated with the first pressure container at a first end and communicated with the cryoablation device at a second end;

the outer layer of the first pipeline is communicated with the second pipeline at a first end, and is communicated with the inner layer of the first pipeline at a second end.

Optionally, a first output valve is configured on the first pipeline, the first output valve has an output channel communicated with the inner layer and a feedback channel communicated with the outer layer, and the opening and closing of the first output valve controls the opening and closing of the output channel and the feedback channel;

and a second electromagnetic valve for controlling the on-off of the second pipeline is arranged on the second pipeline.

Optionally, the first pressure vessel is configured with a first liquid level sensor to obtain a first current liquid level, and when the first current liquid level meets a preset condition, the first output valve is allowed to be opened.

Optionally, a first temperature sensor is disposed on the first pipe adjacent to the second end, so as to obtain a first current temperature of the inner layer;

and when the first current temperature meets a preset condition, the first output valve and the second electromagnetic valve are closed.

Optionally, a safety relief valve is arranged on the outer layer of the first pipeline.

Optionally, during precooling, the liquid-phase cold working medium further enters the cryoablation apparatus from the second end of the inner layer of the first pipeline, the working medium precooling system further includes a seventh pipeline, and the liquid-phase frozen working medium sequentially flows through the inner layer of the first pipeline, the cryoablation apparatus, and the seventh pipeline from the first pressure vessel to the second pressure vessel.

Optionally, the second pressure vessel is connected to the first pressure vessel through a fourth pipeline, and a controlled element is configured on the fourth pipeline, and the controlled element is correspondingly turned on and off under an expected condition, so that the pressures of the first pressure vessel and the second pressure vessel are balanced with each other.

Optionally, the seventh pipeline and the second pipeline are connected to the second pressure vessel through a booster pump, so as to increase the working medium pressure in the seventh pipeline and the second pipeline, and then the working medium pressure is delivered to the second pressure vessel.

and when the first current temperature meets a preset condition, the booster pump is turned off in a delayed mode.

The application provides a precooling system carries out the precooling to first pipeline before cryoablation, avoids working medium because of the temperature difference gasification when cryoablation to can also retrieve the working medium of precooling usefulness.

Drawings

FIG. 1 is a schematic illustration of a low pressure fluid system of the present application (some of which are schematic illustrations of a pre-cooling system);

FIG. 2 is a schematic view of a liquid cryogen tube-in-tube configuration;

FIG. 3 is a schematic view of a liquid refrigerant tube gas-liquid separation device;

FIG. 4 is a schematic view of a liquid cryogen delivery valve;

FIG. 5 is a schematic diagram of a liquid cryogen vessel configuration;

FIG. 6 is a schematic diagram of a phase change pressure vessel;

fig. 7 to 12 are method flowcharts, and the connection relationship between the diagrams can refer to the corresponding marks of the boundary parts.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

In the field of cryoablation, phase-change freezing of liquid freezing media has a higher freezing efficiency than throttling freezing of gaseous freezing media. The common liquid freezing working medium is liquid nitrogen, but the liquid nitrogen is easy to generate phase change in a conveying pipeline to generate 'air blockage', so that the pressure in the pipeline is overhigh, the output quantity of the liquid nitrogen is influenced, the system freezing and melting range is unstable, and the consistent melting effect is difficult to form.

The existing liquid nitrogen working medium cryoablation system solves the problem of air blockage by using supercritical pressure transmission, but the cryoablation system has the problems of high working pressure and potential safety hazard, and has higher requirements on materials of equipment such as a liquid nitrogen transmission pipeline and the like, and the cost is high.

With reference to fig. 1, the present application provides a working medium precooling system for cryoablation, including a first pressure vessel (i.e., liquid working medium pressure vessel C1), a second pressure vessel (i.e., gaseous working medium pressure vessel C2), a first pipeline (i.e., liquid cryogen output pipeline L1), and a second pipeline (i.e., precooled fluid recovery pipeline L2). The first pressure container is used for storing liquid-phase refrigerant, the second pressure container is used for storing gas-phase refrigerant, and the second pipeline is connected between the first pressure container and the second pressure container; the first pipeline is connected between the first pressure container and the cryoablation device (CP) and used for conveying liquid-phase frozen working medium to the cryoablation device in the ablation process, the first pipeline is of an inner-outer double-layer structure, and during precooling, the liquid-phase cold working medium sequentially flows through an inner layer (namely, a flow inlet channel L1-1-3) of the first pipeline, an outer layer (namely, a backflow channel L1-1-2) of the first pipeline and the second pipeline from the first pressure container until reaching the second pressure container. Therefore, one end of the second pipeline is connected to the outer layer of the first pipeline, so that the working medium can be cooled to the inner layer of the whole first pipeline and then flows to the second pressure container to be recovered. The cooling mode of the precooling system is that the liquid freezing working medium is relied on to cool the inner layer, the outer layer and the like which pass through, and precooling can be stopped until the temperature of at least the inner layer meets the preset conditions. When the cryoablation is carried out, the corresponding working medium is output from the inner layer and enters the cryoablation equipment, compared with the existing cryoablation technology, the temperature difference between the temperature of the inner layer and the working medium is reduced or is 0, the gasification amount of the liquid cryoablation working medium is greatly reduced, the air blockage phenomenon is eliminated, and the stability and the safety of the operation are improved. And the working medium on the outer layer can form an isolation layer to block the inner working medium from exchanging heat with the air outside the first pipeline, so that the time of the cryoablation operation is prolonged.

It should be noted that it is not important that the working medium undergoes a state change after or before entering the second pressure vessel, but the key point is a flow path of the working medium, for example, the working medium in the precooling process can be recycled to the second pressure vessel for storage, which is economical and environment-friendly.

Wherein one end of the first conduit adjacent to the first pressure vessel is a first end and one end adjacent to the cryoablation apparatus is a second end; the inner layer of the first pipeline is communicated with the first pressure container at the first end and is communicated with the cryoablation device at the second end, and the outer layer of the first pipeline is communicated with the second pipeline at the first end and is communicated with the inner layer of the first pipeline at the second end. The isolation layer covers the whole inner layer, and the gasification amount of the working medium is further reduced.

In one embodiment, the first pipeline is provided with a first output valve (namely, a liquid refrigerant output valve L1-2), the first output valve is provided with an output channel (L1-2-1) communicated with the inner layer and a return channel (L1-2-2) communicated with the outer layer, and the opening and closing of the first output valve control the opening and closing of the output channel and the return channel. Wherein the liquid cryogen output valve (L1-2) comprises two pairs of input-output channels, a first input-output channel (corresponding to output channel L1-2-1) and a second input-output channel (corresponding to return channel L1-2-2); the first input-output passage communicates with a liquid refrigerant pipe inflow passage (L1-1-3); the second input-output passage communicates with a liquid refrigerant pipe return passage (L1-1-2); a first input-output channel for supply of liquid cryogen; the second inlet-outlet passage is used to pre-cool the valve body of the liquid cryogen outlet valve (L1-2). When the liquid refrigerant outlet valve (L1-2) is in an open state, the fluid in the liquid refrigerant pipe inlet passage (L1-1-3) of the liquid refrigerant pipe (L1-1) dynamically flows into and flows out of the first input-output passage.

In this embodiment, a second solenoid valve (i.e., a precooled fluid recovery solenoid valve L2-2) for controlling on/off of the second pipeline is disposed on the second pipeline. In a precooling procedure of a cryoablation process, a precooling fluid recovery solenoid valve (L2-2) is in an open state, and backflow fluid in a liquid refrigerant pipe backflow channel (L1-1-2) dynamically flows into and out of a second input-output channel; after the precooling program of the cryoablation process is finished, the precooled fluid recovery solenoid valve (L2-2) is in a closed state, the backflow fluid in the liquid refrigerant pipe backflow channel (L1-1-2) stops flowing, and the fluid in the second input-output channel stops flowing.

In one embodiment, the first pressure vessel is configured with a first liquid level sensor for acquiring a first current liquid level, and the first output valve is allowed to open when the first current liquid level meets a preset condition. Avoiding the occurrence of flow interruption during precooling or cryoablation.

In another embodiment, a first temperature sensor is disposed on the first pipe adjacent to the second end for acquiring a first current temperature of the inner layer, preferably the first current temperature is the temperature of the inner layer at the first end; and when the first current temperature meets the preset condition, precooling is finished, and the first output valve and the second electromagnetic valve are closed.

In one embodiment, a safety relief valve (L1-3) is provided on the outer layer of the first conduit. The liquid refrigerant pipe backflow channel (L1-1-2) is characterized in that backflow fluid in the liquid refrigerant pipe backflow channel (L1-1-2) dynamically flows in a precooling program in a cryoablation process, and the backflow fluid in the liquid refrigerant pipe backflow channel (L1-1-2) stops flowing after the precooling program in the cryoablation process is finished; after the return fluid in the liquid cryogen tube return passage (L1-1-2) ceases to flow, the fluid pressure within the layer should be limited to within the operating pressure range; the safety pressure relief valve (L1-3) prevents the pressure in the liquid refrigerant pipe backflow channel (L1-1-2) from being too high, and when the pressure is higher than the threshold pressure of the liquid refrigerant pipe backflow channel, the safety pressure relief valve (L1-3) is opened and releases the pressure; when the pressure is lower than the liquid refrigerant pipe return channel threshold pressure, the safety relief valve (L1-3) is closed.

In another embodiment, during pre-cooling, the liquid-phase cold working medium further enters the cryoablation apparatus 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), and the liquid-phase frozen working medium sequentially flows through the inner layer of the first pipeline, the cryoablation apparatus, the seventh pipeline from the first pressure vessel to the second pressure vessel. The internal pipeline of the cryoablation equipment is also cooled, so that the phenomenon of air blockage in the cryoablation equipment is avoided. And the working medium in the precooling process can be recycled to the second pressure container.

In one embodiment, the second pressure vessel is connected to the first pressure vessel via a fourth conduit (i.e., cryoablation working pressure pressurization conduit L4) having a controlled element disposed thereon, the controlled element being switched on and off accordingly in accordance with a desired condition so that the pressures of the first and second pressure vessels are balanced. And when the expected condition is that the first current pressure in the first pressure container is lower than a preset value, the fourth pipeline is communicated, so that the gas-phase working medium in the second pressure container flows into the first pressure container to maintain the pressure of the first pressure container within a working pressure range, and the liquid-phase freezing working medium can be continuously output. The controlled element is a fourth pressure control element and a fourth electromagnetic valve which are sequentially connected in series between the second pressure container and the first pressure container. And the fourth electromagnetic valve is opened when the first current pressure reaches a first pressure preset value, the second pressure container is communicated with the first pressure container, and the fourth pressure control element automatically controls the output pressure of the fourth pressure control element to be smaller than the input pressure of the fourth pressure control element.

The seventh pipeline and the second pipeline are connected to the second pressure container through a booster pump (L8-5) to increase the working medium pressure in the seventh pipeline and the second pipeline and then convey the working medium pressure to the second pressure container. So that the working fluid can circulate. When the precooling is finished (when the first current temperature meets the preset condition), the booster pump is turned off in a delayed mode. So that the working medium in the second pipeline and the seventh pipeline is recycled before the cryoablation. Wherein the delayed closing can be realized by arranging a system delay timer in the system.

The working medium precooling system for cryoablation is transformed on the original cryoablation system, the first pipeline for conveying the working medium is divided into the inner layer and the outer layer, and the precooling system can effectively reduce the gasification amount of the working medium in the cryoablation process and eliminate air blockage. And the working medium on the outer layer is used as an isolation layer to limit the working medium on the inner layer to exchange heat with the air outside the first pipeline, so that the time of cryoablation is prolonged, and particularly in the cryoablation operation, the stability and the safety are improved. And a corresponding pipeline for recycling the working medium is additionally arranged, so that the environment is protected and saved.

With reference to fig. 1 to 6, the present application provides a gas-liquid separation apparatus, and first the inner and outer layer structures of the first pipe in the above embodiment may be understood as including an outer pipe (L1-1-4) and a spacer sleeve (L1-1-5) disposed in the outer pipe, the outer pipe and the spacer sleeve constituting a liquid refrigerant pipe (L1-1), and the spacer sleeve dividing the first pipe into an inner and outer double layer structure in the radial direction.

The gas-liquid separation device is of a cylindrical structure and is arranged in the isolation sleeve, the first end of the cylindrical structure is open, the second end of the cylindrical structure is closed, a first channel (namely a gas-liquid separation device base pipe L1-1-4-2) is arranged inside the cylindrical structure, a second channel is arranged between the outer wall of the cylindrical structure and the inner wall of the isolation sleeve, and a through hole (namely an exhaust hole L1-1-4-3) for communicating the first channel and the second channel is formed in the side wall of the cylindrical structure. Because of the arrangement of the through holes, part of the working medium can enter the first channel, and the gas content of the mass flow of the part of the two-phase flow is higher than the liquid content of the mass flow; and the gas-liquid two-phase flow which flows through the second channel and does not enter a base pipe (L1-1-4-2) of the liquid refrigerant pipe gas-liquid separation device has a mass flow liquid content higher than a mass flow gas content. Further reducing the gasification amount of the working medium in the second channel and reducing the air blocking probability during precooling or ablation. Because the second end of the gas-liquid separation device is closed, the working medium entering the first channel flows to the first end, and the flow direction of the working medium entering the first channel is opposite to that of the working medium entering the second channel. And (3) further analyzing by combining the flow path of the working medium in the first path, wherein the flow path of the working medium is also divided into two paths: the third path is from the second channel to the cryoablation device or the outer layer; the fourth path is from the second channel, the through hole, the first channel to the first end of the first channel.

The working medium stored in the first pressure container in the embodiment is liquid nitrogen, the proportion of liquid nitrogen gasification influenced by temperature is reduced, and meanwhile, nitrogen gasified due to unavoidable factors such as friction is separated from the liquid nitrogen, so that the phenomenon of gas blockage is avoided, the output liquid nitrogen dosage is stable and controllable, and the stable cryoablation effect is realized.

The method for reducing air 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 refrigerant pipe (L1-1) is a sleeve structure and at least comprises two or more sleeve structures; comprising: the liquid refrigerant pipe heat insulation channel, the liquid refrigerant pipe return channel (L1-1-2), the liquid refrigerant pipe inflow channel (L1-1-3) and the liquid refrigerant pipe gas-liquid separation device (L1-1-4). The liquid refrigerant pipe (L1-1) is sequentially provided with a heat insulation channel (L1-1-1), a backflow channel (L1-1-2) and a flow inlet channel (L1-1-3) from outside to inside through the three channels, the heat insulation channel can be communicated with the backflow channel (L1-1-2) and flow through the same working medium, or can be not communicated with the backflow channel (L1-1-2) and the flow inlet channel (L1-1-3) and flow through other low-temperature working mediums, so that heat exchange is further blocked. In other embodiments, heat exchange is blocked by providing an insulating layer on the outer layer.

The guide groove used for forming the second channel is formed in the outer wall of the tubular structure, the guide groove is communicated with the first end and the second end, so that the working medium can flow on the guide groove, and the through holes are formed in the groove wall of the guide groove for effective gas-liquid separation. The outer wall of the cylindrical mechanism is attached to the inner wall of the isolation sleeve, the guide groove is of a groove structure, working media can only flow through the guide groove, and then the working media can certainly pass through the through hole, so that the gas-liquid separation efficiency is improved. Under the cross section, the second channel is enclosed by the cell wall of guiding gutter and the inner wall of spacer sleeve, and wherein the cell wall of guiding gutter is the arc, and the cell wall is smooth, reduces the heat because of the friction production with working medium. The through hole is provided with an arc-shaped bottom, and is circular in shape and convenient to process.

In order to further improve the separation efficiency, the method adopted is that the diversion trench is spirally wound on the outer wall of the cylindrical structure to form a spiral channel, so that the flowing path of the working medium is prolonged. Or a plurality of through holes are distributed along the diversion trench. Wherein the guiding gutter has arranged 1 ~ 8 through-holes in spirally around every round of putting, and these through-holes are equidistant distribution in tubular structure's circumference.

In one embodiment, the first end of the isolation sleeve extends out of the first end of the outer tube, the extended part serves as a bottom inserting tube, and the length of the bottom inserting tube at least can extend to be below the liquid level in the first pressure container, so that precooling and ablation can continuously output liquid-phase working medium. And the first end of the outer pipe is positioned outside the first pressure container, so that the working medium is output from the first end of the inner layer and then returns to the first end of the outer layer through the second end to flow out, and most or all of the inner layer is cooled.

The first end of the cylindrical structure and the first end of the spacer sleeve are axially adjacent to each other. The mutual proximity is understood that the first end of the gas-liquid separation device is also positioned below the liquid level in the first pressure container, so that the working medium directly enters the second channel for gas-liquid separation when being output, and the working medium entering the first channel can return to the first pressure container and be liquefied, thereby realizing local circulation and saving resources.

Referring to FIG. 4, in one embodiment, the first conduit is configured with an outlet valve (i.e., liquid cryogen outlet valve L1-2) having an outlet passage (L1-2-1) in communication with the inner layer and a return passage (L1-2-2) in communication with the outer layer. The liquid cryogen output valve (L1-2) comprises two pairs of input-output channels, a first input-output channel (corresponding to the output channel) and a second input-output channel (corresponding to the return channel); the first input-output passage communicates with a liquid refrigerant pipe inflow passage (L1-1-3); the second input-output passage communicates with a liquid refrigerant pipe return passage (L1-1-2); when the liquid refrigerant outlet valve (L1-2) is in an open state, the fluid in the liquid refrigerant pipe inlet passage (L1-1-3) of the liquid refrigerant pipe (L1-1) dynamically flows into and flows out of the first input-output passage.

The gas-liquid separation device can improve the mass flow liquid containing rate of the working medium conveyed to the cryoablation equipment, and further reduces the gas blockage phenomenon.

Referring to fig. 1, an embodiment of the present application discloses a low pressure fluid system for enhancing interventional cryoablation performance, comprising at least one of: the system comprises a liquid working medium pressure container (C1), a gaseous working medium pressure container (C2), a phase change pressure container (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), an air return recovery pipeline (L7), a system flow monitoring and recovery condition control pipeline (L8), a vacuum degree creation pipeline (L9) and cryoablation equipment (CP) as interventional ablation equipment.

The above modules, containers, conduits and related apparatus and methods may be applied to low pressure cryoablation, for example, less than 3MPa (e.g., about 0.5MPa operating pressure), each of which may independently implement certain unit operations and in some cases may be integrated with each other into a relatively complete low pressure fluid system, and are described below with respect to the components, but not strictly limited to the configuration at the same time:

1) the pressure vessel for accommodating liquid-phase working medium and gas-phase working medium: the pressure vessel comprises a liquid working medium pressure vessel (a first pressure vessel C1), a gaseous working medium pressure vessel (a second pressure vessel C2) and a phase change pressure vessel (a third pressure vessel C3).

A first pressure container (C1), wherein a liquid-phase working medium is stored in the first pressure container C1, is connected with the cryoablation device CP through a first pipeline L1 and is conveyed;

the first pressure vessel C1 is connected to the second pressure vessel C2 via a fourth conduit L4; a third pressure container C3 is arranged in the first pressure container C1 and can change the phase of the liquid-phase working medium into a gas-phase working medium.

The first pressure container C1 is provided with a third pipeline L3 for exhausting and decompressing;

a liquid working medium pressure vessel (C1), preferably a dewar pressure vessel, for storing liquid working medium for the freezing process in the cryoablation procedure; the method comprises the following steps: a liquid working medium pressure sensor (C1-1) and a liquid working medium liquid level sensor (C1-2).

A gaseous working medium pressure container (namely a second pressure container C2), wherein a gaseous working medium is stored in the second pressure container (C2), and is connected with the first pressure container (C1) through a fourth pipeline L4 and conveys the gaseous working medium to the first pressure container (C1);

the second pressure vessel (C2) is connected with the third pressure vessel (C3) through a fifth pipeline (L5) and receives the gas-phase working medium from the third pressure vessel (C3);

the second pressure container (C2) is connected with the cryoablation device (CP) through a sixth pipeline (L6) and transmits the heated gaseous working medium;

the second pressure vessel (C2) is connected to the gaseous working medium of the cryoablation device (CP) and/or of the first line (L1) via an eighth line (L8).

The Dewar pressure vessel is preferably used for storing gaseous working media which are replaced before use, rewarming process and recovered by the air return channel in the cryoablation procedure; the method comprises the following steps: a gaseous working medium pressure sensor (C2-1) and a gaseous working medium pressure relief valve (C2-2).

And the phase change pressure vessel (namely, the third pressure vessel C3) is connected and conveyed to the second pressure vessel (C2) through a fifth pipeline (L5).

The gas phase change device is used for changing a liquid phase working medium into a gas phase working medium, and the gas after phase change is conveyed to a gas working medium pressure container (C2) through a gas working medium output pipeline (L5) through a pressure control element (L5-5). The method comprises the following steps: the device comprises a liquid working medium one-way circulation 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).

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

The delivery device of the above embodiment, in which the liquid refrigerant output pipeline (the first pipeline L1) is used for delivering liquid working medium, includes:

a liquid cryogen tube (L1-1); a liquid cryogen outlet valve (L1-2); a safety relief valve (L1-3); the liquid refrigerant output pipeline pressure transmitter (L1-4) and the temperature sensor (L1-5) participate in closed-loop control, and are used for monitoring the state parameters of the fluid working medium entering the flexible cryoprobe; the liquid cryogen is delivered out a check valve (L1-6) to avoid back flow.

Secondly, gas working media flow through the precooling fluid recovery pipeline (namely the second pipeline (L2)), one end of the second pipeline (L2) is connected with the first pipeline (L1), and the other end of the second pipeline is connected with the eighth pipeline (L8) and finally conveyed into the second pressure container (C2).

A second conduit (L2) for conveying fluid working medium to a system flow monitoring and recovery condition control conduit (L8) during a pre-cooling process of a cryoablation procedure, comprising:

a pre-cooling fluid recovery pipe (L2-1); a precooling fluid recovery electromagnetic valve (L2-2), wherein a heat exchanger in a cryoablation procedure is opened and is closed after reaching a precooling temperature threshold range; a pre-chilled fluid recovery check valve (L2-3) prevents backflow.

(iii) a cryoablation working pressure relief conduit (i.e. a third conduit (L3) connected to the first pressure vessel (C1) for relieving pressure from the liquid working medium dewar pressure vessel (C1).

A cryoablation working pressure reducing tube (L3-1); and the cryoablation working pressure reducing electromagnetic valve (L3-2) is opened when the pressure of the liquid working medium in the liquid nitrogen working medium pressure container (C1) is higher than a release pressure threshold value, and is closed when the pressure of the liquid working medium is lower than the release pressure threshold value.

A cryoablation working pressure pressurization pipeline (i.e., a fourth pipeline (L4) which connects the first pressure vessel (C1) and the second pressure vessel (C2) and is used for inputting the gaseous working medium in the gaseous working medium pressure vessel (C2) into the liquid working medium dewar pressure vessel (C1) to perform pressurization, including:

a cryoablation working pressure booster pipe (L4-1); and the cryoablation working pressure boosting electromagnetic valve (L4-2) is opened when the pressure of the liquid working medium in the liquid nitrogen working medium pressure container (C1) is lower than a boosting pressure threshold value, and is closed when the pressure of the liquid working medium is higher than the boosting pressure threshold value. A cryoablation working pressure control element (L4-3) participates in closed loop control for adjusting the cryoablation working pressure.

The gaseous working medium output pipeline (namely, the fifth pipeline (L5) connects the third pressure container (C3) with the second pressure container (C2) and is used for inputting the gaseous working medium in the phase change pressure container (C3) to the gaseous working medium pressure container (C2) for pressurization, and the method comprises the following steps:

a gaseous working medium output pipe (L5-1), a pressure monitoring element of a phase change pressure container (C3): a phase change pressure transmitter (L5-2); the phase change container pressure relief electromagnetic valve (L5-3) is opened and is used for emptying gas-phase working media in the phase change pressure container (C3) or creating a pressure difference between the liquid working medium pressure container (C1) and the phase change pressure container (C3) so that the liquid working media enter the phase change pressure container (C3) from the liquid working medium pressure container (C1) and are closed after the liquid working media enter; when the pressure threshold of the phase change pressure transmitter (L5-2) is higher than the gaseous working medium output pressure threshold, the gaseous working medium output electromagnetic valve (L5-4) is opened, otherwise, the gaseous working medium output electromagnetic valve is closed; the gaseous working medium output pressure control element (L5-5) is used for adjusting the pressure in the gaseous working medium pressure container (C2).

Sixthly, the replacement and rewarming pipeline (namely, a sixth pipeline (L6) connects the second pressure container (C2) with the cryoablation device (CP) and is used for selectively heating the gaseous working medium in the gaseous working medium pressure container (C2) in the replacement process in the cryoablation procedure and then conveying the heated gaseous working medium to the cryoablation device (CP), and the method comprises the following steps:

a replacement and rewarming tube (L6-1); a replacement and rewarming solenoid valve (L6-2) that opens when in a replacement procedure in a cryoablation procedure and closes after the replacement procedure for replacing air within the cryoablation apparatus; when the gas working medium is in a rewarming process in a cryoablation program, the replacement and rewarming heat exchanger (L6-3) is started and used for heating the gas working medium in the replacement and rewarming pipe (L6-1) to reach a threshold temperature, and the rewarming temperature sensor (L6-4) participates in the rewarming process and is matched with the adjustment of the heating power of the replacement and rewarming heat exchanger (L6-2), so that the gas working medium in the replacement and rewarming pipe (L6-1) reaches the threshold temperature; a replacement and rewarming one-way valve (L6-5) to avoid reverse flow.

Seventhly, one end of a return gas recovery pipeline (i.e. a seventh pipeline (L7)) is connected to the cryoablation apparatus (CP), and the other end of the return gas recovery pipeline is connected to an eighth pipeline (L8), so that return gas generated in the freezing process in the cryoablation procedure is delivered to a system flow monitoring and recovery condition control pipeline (L8), and the return gas recovery pipeline comprises:

a return air recovery pipe (L7-1); the return gas recovery pipeline is provided with a one-way valve (L7-2) to avoid reverse flow.

One end of an eighth pipeline (L8) is connected with a seventh pipeline (L7) and a second pipeline (L2) at the same time, the other end of the eighth pipeline is connected with a second pressure container (C2) and is used for heating fluid working media flowing from a precooling fluid recovery pipeline (L2) in a precooling process in a cryoablation procedure and then pumping the fluid working media to a gaseous working media pressure container (C2), and the fluid working media flowing into a return gas recovery pipeline (L7) in the cryoablation procedure are heated and then pumped to the gaseous working media pressure container (C2) after the flow is measured by a flowmeter in the freezing process, and the measured flow participates in pressure control of the system, and the system comprises the following steps:

a system flow monitoring and recovery condition control pipe (L8-1); a system flow monitoring and recovery condition control heat exchanger (L8-2) for heating fluid flowing from a pre-cooled fluid recovery line (L2) during a pre-cooling process of a cryoablation procedure to a threshold temperature; and freezing the fluid flowing from the return air recovery line (L7) during the freezing process and bringing it to a threshold temperature during the cryoablation process; the system flow monitoring and recovery condition control temperature sensor (L8-3) participates in closed-loop control and is used for adjusting the heating power of the system flow monitoring and recovery condition control heat exchanger (L8-2) in a matching manner, so that the fluid in the system flow monitoring and recovery condition control pipe (L8-1) reaches a threshold temperature; if the fluid working medium cannot reach the threshold temperature after being heated, the gas working medium recovery release valve (L8-7) is opened, and the fluid working medium is discharged to the atmosphere; the system flow monitoring and recovery condition control flowmeter (L8-4) is mainly used for monitoring the freezing process in a cryoablation program, and the fluid flow entering the system flow monitoring and recovery condition control pipe (L8-1) from the return air recovery pipe (L7-1) participates in closed-loop control, is used for prejudging the cryoablation effect, and is matched with pressure regulation to enable the cryoablation effect to meet the expectation. The system flow monitoring and recovery condition control extraction booster pump (L8-5), and the adjustment of the pumping power is matched with the adjustment of the working pressure, so as to further promote the smooth air return and enable the cryoablation effect to reach the expectation. System flow monitoring and recovery conditions control a check valve (L8-6) to prevent backflow.

Ninthly, a vacuum degree creation pipeline (i.e., a ninth pipeline L9) connects the cryoablation apparatus (CP) and the vacuum apparatus (L9-3) for creating a high vacuum degree for the cryoablation apparatus (CP) to achieve a good vacuum insulation effect includes:

a vacuum level creation pipe (L9-1); the vacuum gauge (L9-2) is used for monitoring whether the vacuum degree reaches a threshold value requirement; the vacuum level creating pump set is used for creating high vacuum level, and the flexible cryoprobe has good vacuum insulation effect.

3) A cryoablation apparatus (CP) comprising a thermometric sensor and a heating element.

A cryoablation apparatus (CP) for performing a cryoablation procedure on a lesion after entering a human body through a natural orifice, comprising:

structures for enhancing interventional cryoablation performance; a distal thermocouple (CP1) of the cryoablation device for monitoring the temperature within the cryoprobe and participating in closed loop control; the distal end of the cryoablation device is a nickel-chromium wire used for the rewarming process in the cryoablation procedure. The cryoablation device may be a flexible cryoprobe or the like.

The operation of the low pressure fluid system will be described with reference to fig. 7 to 12

The steps in the drawings are shown in order as indicated by the arrows, but the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in the figures may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or alternately with other steps or at least some of the sub-steps or stages of other steps.

1) Starting a system, initializing, and reading a control threshold parameter stored in a memory; and simultaneously acquiring data of system sensors.

2) Firstly, the liquid level in a liquid working medium Dewar pressure container (C1) is judged, LLC1-2_ Lower Limit is a low liquid level early warning threshold value of the container, and a judgment program is executed:

if the current liquid level LLC1-2_ CL of the liquid working medium liquid level sensor (C1-2) is less than LLC1-2_ Lower Limit, the system determines that the liquid level cannot maintain the cryoablation program, namely the LLC1-2_ Lower Limit is the volume of liquid nitrogen required by the redundancy-containing primary cryoablation program. Then, executing a liquid nitrogen supplementing program, and when LLC1-2_ CL is more than or equal to LLC1-2_ Upper Limit; and (5) ending liquid nitrogen canning.

If the current liquid level LLC1-2_ CL of the liquid working medium liquid level sensor (C1-2) is more than or equal to LLC1-2_ Lower Limit, the system considers that the cryoablation program can be executed.

3) Judging the pressure in a liquid working medium Dewar pressure container (C1), wherein PC1_ IWP is the pressure threshold value of the pressure container during initialization; executing a judgment program:

if the current pressure PC1-1_ CP of the liquid working medium pressure sensor (C1-1) is not more than PC1_ IWP, the system considers that the pressure in the pressure container meets the pressure requirement during initialization, and can continue to execute the subsequent program; PC1_ IWP is the initialization pressure of the liquid working medium dewar pressure vessel (C1) prior to use in a cryoablation procedure, which is typically the pressure at ordinary rest when the liquid working medium dewar pressure vessel (C1) is not in use. Note: the initial pressure PC1_ IWP of the pressure vessel is less than the working pressure PC1_ WP of the liquid working medium Dewar pressure vessel.

If the current pressure PC1-1_ CP of the liquid working medium pressure sensor (C1-1) is larger than PC1_ IWP, a pressure relief program is executed, and a pressure reduction electromagnetic valve (L3-2) for the cryoablation working pressure is opened for pressure relief until PC1-1_ CP is not more than PC1_ IWP.

4) Judging the pressure in a gaseous working medium pressure container (C2), wherein PC2_ IWP is the pressure threshold value of the pressure container during initialization; executing a judgment program:

if the current pressure PC2-1_ CP of the gaseous working medium pressure sensor (C2-1) is not more than PC2_ IWP, the system considers that the pressure in the pressure container meets the pressure requirement during initialization, and can continue to execute the subsequent program; PC2_ IWP is the initialization pressure of the gaseous working medium pressure container (C2) before the use of the cryoablation program, and the pressure is usually the gaseous working medium stored in the gaseous working medium pressure container (C2) after the last cryoablation program; because the gas in the gaseous working medium pressure container (C2) is the gas for recovering the precooling process and the cryoablation process, the gas is output in the rewarming process, and in order to ensure the normal recovery of the next operation in the precooling and cryoablation processes, the PC2_ IWP of the pressure is less than the working pressure PC2_ WP of the gaseous working medium pressure container (C2).

And if the current pressure PC2-1_ CP of the gaseous working medium pressure sensor (C2-1) is larger than PC2_ IWP, executing a pressure relief program, and opening the gaseous working medium pressure relief valve (C2-2) for pressure relief until PC2-1_ CP is not more than PC2_ IWP.

5) Judging the pressure in the phase-change pressure container (C3), wherein the PC3_ IWP is the pressure threshold value of the pressure container during initialization; executing a judgment program:

if the current pressure PL5-2_ CP of the phase change pressure transmitter (L5-2) is not more than PC3_ IWP; the system considers the pressure within the pressure vessel to meet the pressure requirements at initialization and may proceed with the subsequent procedure. This pressure PC3_ IWP < the working pressure PC3_ WP inside the phase change pressure vessel (C3).

If the current pressure PL5-2_ CP of the phase change pressure transmitter (L5-2) is larger than PC3_ IWP, a pressure relief program is executed, and a phase change container pressure relief electromagnetic valve (L5-3) is opened for pressure relief until PL5-2_ CP is not larger than PC3_ IWP.

6) Judging the current pressure PL5-2_ CP of the phase change pressure transmitter (L5-2) is greater than the current pressure PC2-1_ CP of the gaseous working medium pressure sensor (C2-1) of the PC2-1_ CP, opening a gaseous working medium output electromagnetic valve (L5-4), and setting the output pressure of a gaseous working medium output pressure control element (L5-5): PL5-5_ SP _ OUT > PC2-1_ CP; at the moment, the gaseous working medium in the phase change pressure container (C3) enters the gaseous working medium pressure container (C2); until PL5-2_ CP-PC2-1_ CP <. DELTA.P 0, namely the pressure in the current phase change pressure vessel (C3) is equal to the pressure in the gaseous working medium pressure vessel (C2), closing the gaseous working medium output electromagnetic valve (L5-4); and the output of the gaseous working medium output pressure control element (L5-5) is cut off. The gaseous working medium of the phase-change pressure container (C3) is utilized, and the utilization rate is improved.

7-1) opening a liquid refrigerant output valve (L1-2), firstly entering a precooling program of a cryoablation process, and enabling all elements in a precooling fluid recovery pipeline (L2) and a system flow monitoring and recovery condition control pipeline (L8) to enter a working state. And opening a precooling fluid recovery solenoid valve (L2-2), and controlling the start of a heat exchanger (L8-2) by system flow monitoring and recovery conditions.

The system flow monitoring and recovery condition control flow meter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) have restrictions on fluid temperature, so the system sets a temperature threshold: TL8-2_ ET _ Lower Limit: system flow monitoring and recovery conditions control the first heat exchange temperature of the heat exchanger and TL8-2_ ET _ Upper Limit: the system flow monitoring and recovery condition controls a second heat exchange temperature of the heat exchanger; corresponding to the lower limit of the temperature range and the upper limit of the temperature range, respectively.

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

TL8-3_ CT is more than or equal to TL8-2_ ET _ Lower Limit & & TL8-3_ CT is less than or equal to TL8-2_ ET _ Upper Limit; and a gas working medium recovery release valve (L8-7) is closed, and fluid enters a gas working medium pressure container (C2) for pressurization through a system flow monitoring and recovery condition control flowmeter (L8-4) and a system flow monitoring and recovery condition control extraction booster pump (L8-5).

If: TL8-3_ CT < TL8-2_ ET _ Lower Limit | | | TL8-3_ CT > TL8-2_ ET _ Upper Limit; and opening a gas working medium recovery release valve (L8-7). And calling a fuzzy self-tuning PID temperature control algorithm, closing a gas working medium recovery release valve (L8-7) after the temperature meets TL8-3_ CT (being more than or equal to TL8-2_ ET _ Lower Limit & & TL8-3_ CT (being less than or equal to TL8-2_ ET _ Upper Limit), and enabling the fluid to enter a gaseous working medium pressure container (C2) for pressurization through a system flow monitoring and recovery condition control flowmeter (L8-4) and a system flow monitoring and recovery condition control extraction booster pump (L8-5).

The cycle of the above steps is pressurized to event: the current temperature TL1-5_ CT-TL1-5_ PT precooling threshold temperature collected by a liquid refrigerant output pipeline temperature sensor (L1-5) is less than delta T0| (or the current pressure of a gaseous working medium pressure sensor (C2-1) is less than delta P0, and the second pressurization closing pressure PC2_ PB _ CV-PC2-1_ CP is higher than the second pressurization closing pressure of the gaseous working medium pressure container (C2).

If TL1-5_ CT-TL1-5_ PT < [ delta ] T0 occurs in the OR logic, the precooling process is finished, the liquid refrigerant output valve (L1-2) is closed, a system time delay device is started, and a time delay interval Delta T is set, so that after the liquid refrigerant output valve (L1-2) is closed, residual fluid in the liquid refrigerant output pipeline (L1) and the precooling fluid recovery pipeline (L2) enters a gaseous working medium pressure container (C2); the system flow monitoring and recovery condition control draw booster pump (L8-5) was then shut down.

If TL1-5_ CT-TL1-5_ PT <. DELTA.T 0 is NO, then event PC2_ PB _ CV-PC2-1_ CP <. DELTA.P 0 must have occurred; the pressure in the gaseous working medium pressure container (C2) meets the pressurization requirement; therefore shut down system flow monitoring and recovery condition control draw booster pump (L8-5); opening a gas working medium recovery release valve (L8-7) to discharge the fluid in the pipeline into the atmosphere until an event TL1-5_ CT-TL1-5_ PT <. DELTA.T 0 occurs, and achieving a precooling condition;

then closing the liquid refrigerant output valve (L1-2), starting a system time delay device, delaying the time interval delta t, and enabling residual fluid in the liquid refrigerant output pipeline (L1) and the precooling fluid recovery pipeline (L2) to enter a gaseous working medium pressure vessel (C2) after the liquid refrigerant output valve (L1-2) is closed; the system flow monitoring and recovery condition control draw booster pump (L8-5) was then shut down.

Next, judging the pressure condition of the gas working medium entering the gas working medium pressure container (C2), and opening a gas working medium pressure relief valve (C2-2) for pressure relief when the current pressure of a second pressure reduction opening threshold PC2_ RP _ OV-PC2-1_ CP gas working medium pressure sensor (C2-1) is less than delta P0; and closing the gaseous working medium pressure relief valve (C2-2) until the second decompression closing threshold value <. DELTA.P 0 of the current pressure PC2-1_ CP-PC2_ RP _ CV of the gaseous working medium pressure sensor (C2-1).

7-2) judging that the current pressure PL5-2_ CP of the phase change pressure transmitter (L5-2) is more than or equal to the current pressure PC1-1_ CP of the PC1-1_ CP liquid working medium pressure sensor (C1-1); starting a phase change container pressure relief solenoid valve (L5-3), and when the current pressure PL5-2_ CP-atm of a phase change pressure transmitter (L5-2) is less than delta P0& & a liquid level sensor (C3-4), a first liquid level closing threshold LLC3-4_ CV-LLC 3-4_ CL liquid level sensor (C3-4) of the phase change pressure container (C3) has the current liquid level value less than delta L0; and closing the pressure relief electromagnetic valve (L5-3) of the phase change container, and starting the phase change heating device (C3-2) for heating.

If the current pressure PL5-2_ CP < PC1-1_ CP & & phase change pressure container (C3) liquid level sensor (C3-4) of the phase change pressure transmitter (L5-2) is judged, the current liquid level value LLC3-4_ CL < LLC3-4_ Lower Limit liquid level sensor (C3-4) is judged to be a first low liquid level threshold value; starting a phase change container pressure relief solenoid valve (L5-3), and when the current pressure PL5-2_ CP-atm of a phase change pressure transmitter (L5-2) is less than delta P0& & a liquid level sensor (C3-4), a first liquid level closing threshold LLC3-4_ CV-LLC 3-4_ CL liquid level sensor (C3-4) of the phase change pressure container (C3) has the current liquid level value less than delta L0; and closing the pressure relief electromagnetic valve (L5-3) of the phase change container, and starting the phase change heating device (C3-2) for heating.

7-2-2) if judging that the current pressure PL5-2_ CP of the phase change pressure transmitter (L5-2) is less than PC1-1_ CP & & phase change pressure container (C3) liquid level sensor (C3-4) and the current liquid level value LLC3-4_ CL is more than or equal to the first low liquid level threshold of the LLC3-4_ Lower Limit liquid level sensor (C3-4), starting heating by the phase change heating device (C3-2).

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) is larger than the third Lower pressure increase threshold of PC3_ PB _ Lower Limit; and the current temperature TC3-5_ CT < TC3-5_ Upper Limit collected by the temperature sensor (C3-5): a temperature sensor (C3-5) a first high temperature threshold; the phase change heating device (C3-2) continues heating.

Until: the current pressure of the acquired current temperature TC3-5_ CT is more than or equal to a first high-temperature threshold or a third pressurization closing threshold PC3_ PB _ CV-PL5-2_ CP variable pressure transmitter (L5-2) of a TC3-5_ Upper Limit temperature sensor (C3-5) and is less than delta P0; the heating device (C3-2) stops heating.

If the current pressure PL5-2_ CP of the phase change pressure transmitter (L5-2) is not more than the third Lower pressure increase threshold of the PC3_ PB _ Lower Limit and the current temperature TC3-5_ CT collected by the temperature sensor (C3-5) is not less than the first high temperature threshold of the TC3-5_ Upper Limit temperature sensor (C3-5), stopping heating, invalidating the pressure increase at this time, and executing the pressure increase process again. Otherwise, the heating is continued until the above certain judgment condition appears.

When the device meets the requirement and the current temperature TC3-5_ CT collected by the temperature sensor (C3-5) is more than or equal to the first high temperature threshold value of the TC3-5_ Upper Limit temperature sensor (C3-5) or the current pressure of the third supercharging closing threshold value PC3_ PB _ CV-PL5-2_ CP variable pressure transmitter (L5-2) is less than delta P0, an output program is executed. And (3) opening the gaseous working medium output electromagnetic valve (L5-4), and setting the output pressure of the gaseous working medium output pressure control element (L5-5): PL5-5_ SP _ OUT > PC2-1_ CP; at the moment, the gaseous working medium in the phase change pressure container (C3) enters the gaseous working medium pressure container (C2); until the current pressure PL5-2_ CP-PC3_ PB _ OV of the variable pressure transmitter (L5-2) is less than delta P0L (or) the current pressure PL5-2_ CP-PC2-1_ CP gaseous working medium pressure sensor (C2-1) of the variable pressure transmitter (L5-2) is less than delta P0L (here, the limitation is determined by a controller, after the gaseous working medium pressure container (C2) is gradually pressurized, the PC2-1_ CP is gradually increased, but the requirement of the pressure controller is that the upstream pressure should be greater than the downstream pressure, so the logic > | I (or) the gaseous working medium pressure container (C2) is provided with the second pressurization closing pressure PC2_ PB _ CV-PC2-1_ CP closing the gaseous working medium pressure sensor (C2-1) to close the gaseous working medium output electromagnetic valve (L5-634) when the current pressure of the gaseous working medium pressure sensor (C6356) is less than delta P0), and the gaseous working medium output pressure control element (L5-5) is switched off.

The boosting process described above may be cycled through multiple cycles until the event: the current pressure of the second pressurization closing pressure PC2_ PB _ CV-PC2-1_ CP gaseous working medium pressure sensor (C2-1) of the gaseous working medium pressure container (C2) is less than delta P0, and the initialization pressurization process of the gaseous working medium pressure container (C2) is finished.

In order to prevent the pressure in the phase change pressure vessel C3 from being high at the time of stopping, a pressure relief judgment is introduced: the current pressure PL5-2_ CP-PC3_ RP _ OV phase change pressure vessel (C3) of the phase change pressure transmitter (L5-2) is subjected to third pressure reduction opening threshold value <. DELTA.P 0, a phase change vessel pressure reduction electromagnetic valve (L5-3) is opened, and when the current pressure PL5-2_ CP-PC3_ RP _ CV phase change pressure vessel (C3) of the phase change pressure transmitter (L5-2) is subjected to third pressure reduction closing threshold value <. DELTA.P 0, the phase change vessel pressure reduction electromagnetic valve (L5-3) is closed. To prevent excessive pressure in C3.

8) After the process, the gaseous working medium pressure container (C2) meets the working pressure requirement: PC2_ WP; the phase change pressure vessel (C3) also meets its operating pressure requirements; PC3_ WP; the liquid cryogen output line (L1) has achieved adequate pre-cooling.

Therefore, the method has the following requirements of the cryoablation procedure, and the method comprises the steps of detecting or accessing system consumables until the system accesses the consumables, then accessing the system into a liquid working medium Dewar pressure container (C1) to build pressure and replace gas in the consumables.

9) Opening a replacement and rewarming electromagnetic valve (L6-2) and entering a replacement program; the purpose of replacement is to replace the air and moisture in the internal pipeline of the consumable into gas working medium in the gas working medium pressure container (C2) before the freezing process. Starting a replacement and rewarming heat exchanger (L6-3), and heating the temperature of the replacement gas to room temperature after a fuzzy self-setting PID temperature control algorithm, namely meeting the condition that TL6-4_ CT-room temperature is less than delta T0; the gas enters a system flow monitoring and recovery condition control pipeline (L8) after passing through a return gas recovery pipeline (L7). Then, a recovery flow similar to the precooling process is used for entering a gaseous working medium pressure container (C2), and the following steps are carried out:

TL8-3_ CT is more than or equal to TL8-2_ ET _ Lower Limit & & TL8-3_ CT is less than or equal to TL8-2_ ET _ Upper Limit; and (3) closing a gas working medium recovery release valve (L8-7), and pumping the fluid into a gas working medium pressure container (C2) for pressurization through a system flow monitoring and recovery condition control flowmeter (L8-4) and a system flow monitoring and recovery condition control pumping booster pump (L8-5).

If: TL8-3_ CT < TL8-2_ ET _ Lower Limit | | | TL8-3_ CT > TL8-2_ ET _ Upper Limit; and opening a gas working medium recovery release valve (L8-7). And calling a fuzzy self-tuning PID temperature control algorithm, closing a gas working medium recovery release valve (L8-7) after the temperature meets TL8-3_ CT (greater than or equal to TL8-2_ ET _ Lower Limit & & TL8-3_ CT (less than or equal to TL8-2_ ET _ Upper Limit), and enabling fluid to enter a gas working medium pressure container (C2) for pressurization through a system flow monitoring and recovery condition control flowmeter (L8-4) and a system flow monitoring and recovery condition control extraction booster pump (L8-5).

The displacement process is output from the gaseous working medium pressure container (C2) and then flows back to the gaseous working medium pressure container (C2); the process does not cause drastic changes in pressure, so the process does not make pressure judgments. In addition, the whole replacement process is maintained for a time Δ t 1.

The permutation process is ended and Probe _ ZH _ Flag is transmitted.

10) Raising the liquid working medium Dewar pressure container (C1) to working pressure; opening a cryoablation working pressure pressurization solenoid valve (L4-2); setting an output pressure PL4-3_ SP _ OUT > PC1_ PB _ CV first boost initialization closing threshold of a cryoablation working pressure control element (L4-3); so that the gaseous working medium pressure vessel (C2) pressurizes the liquid working medium Dewar pressure vessel (C1) through the cryoablation working pressure pressurization pipeline (L4) until: first boost initialization closing threshold PC1_ PB _ CV-PC1-1_ CP liquid working medium pressure sensor (C1-1)

Current pressure collected < [ delta ] P0; and (3) after the liquid working medium Dewar pressure container (C1) is pressurized, closing the cryoablation working pressure pressurizing electromagnetic valve (L4-2) and turning off the cryoablation working pressure control element (L4-3).

And after pressure build-up before ablation of the liquid working medium Dewar pressure container (C1) is finished, sending PC1_ PreCyro _ Flag.

11-1) when an event: probe _ ZH _ Flag occurs 1& & PC1_ precero _ Flag ═ 1, and cryoablation is ready. Waiting for an event: probe _ Cyro _ Star is 1; setting the cryoablation delay time: Δ t 2; opening a liquid cryogen output valve (L1-2); a cryoablation timer2 is started; when the cryoablation time length is delta t2, the freezing process of the Cycle is finished, and the cryocycle times Cryo _ Cycle + + in the cryoablation process; the liquid cryogen output valve (L1-2) is then closed. The freezing process of this cryoablation cycle is ended.

11-2) starting a rewarming process of the cryoablation cycle, starting a replacement and rewarming heat exchanger (L6-3), and meeting the temperature of rewarming gas after a fuzzy self-tuning PID temperature control algorithm: TL6-4_ CT < TL6-3_ RW _ Upper Limit & & TL6-3_ RW _ Lower Limit < TL6-4_ CT. Then, a temperature recovery timer3 is started, when the temperature recovery time in the cryoablation is delta t3, the Cycle number Cryo _ Cycle + + is reset in the cryoablation process; then closing the electromagnetic valve L6-2; the replacement and rewarming heat exchanger (L6-3) was shut off.

After one freezing and rewarming cycle, judging an event:

Cryo_Cycle＝＝Cryo_Set&&ReWarm_Cycle＝＝RW_Set

when it occurs, it indicates the end of the cryocycle, otherwise, it continues to perform the cryoablation procedure.

11-3) in the above process, a recovery process is carried out, and the gas enters a system flow monitoring and recovery condition control pipeline (L8) after passing through a return gas recovery pipeline (L7).

Then, a recovery flow similar to the precooling process is used for entering a gaseous working medium pressure container (C2), and the following steps are carried out:

the system flow monitoring and recovery condition control flow meter (L8-4) and the system flow monitoring and recovery condition control extraction booster pump (L8-5) have restrictions on fluid temperature, so the system sets a temperature threshold: TL8-2_ ET _ Lower Limit: system flow monitoring and recovery conditions control the first heat exchange temperature of the heat exchanger and TL8-2_ ET _ Upper Limit: the system flow monitoring and recovery condition controls a second heat exchange temperature of the heat exchanger; are respectively provided with

The lower limit of the temperature range corresponds to the upper limit of the temperature range.

If: the current fluid temperature collected by a system flow monitoring and recovery condition control temperature sensor (L8-3): TL8-3_ CT is more than or equal to TL8-2_ ET _ Lower Limit & & TL8-3_ CT is less than or equal to TL8-2_ ET _ Upper Limit; and a gas working medium recovery release valve (L8-7) is closed, and fluid enters a gas working medium pressure container (C2) for pressurization through a system flow monitoring and recovery condition control flowmeter (L8-4) and a system flow monitoring and recovery condition control extraction booster pump (L8-5).

If: TL8-3_ CT < TL8-2_ ET _ Lower Limit | | | TL8-3_ CT > TL8-2_ ET _ Upper Limit; and opening a gas working medium recovery release valve (L8-7).

And calling a fuzzy self-tuning PID temperature control algorithm, closing a gas working medium recovery release valve (L8-7) after the temperature meets TL8-3_ CT (greater than or equal to TL8-2_ ET _ Lower Limit & & TL8-3_ CT (less than or equal to TL8-2_ ET _ Upper Limit), and enabling fluid to enter a gas working medium pressure container (C2) for pressurization through a system flow monitoring and recovery condition control flowmeter (L8-4) and a system flow monitoring and recovery condition control extraction booster pump (L8-5). When the event occurs: when the PC2_ PB _ CV-PC2-1_ CP <. DELTA.P 0, the recovered fluid is not entering a gaseous working medium pressure vessel (C2) and is discharged to the atmosphere from a bypass; when the event:

Cryo_Cycle＝＝Cryo_Set&&ReWarm_Cycle＝＝RW_Set

when it happens, it indicates the end of the freezing cycle, otherwise, it continues to execute.

When the cryoablation starts, the vacuum equipment (L9-3) starts to work, and the vacuum degree is set to be vacuum; until the cryoablation procedure is completed.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features. When technical features in different embodiments are represented in the same drawing, it can be seen that the drawing also discloses a combination of the embodiments concerned.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A working medium precooling system for cryoablation, comprising:

2. The working medium precooling system for cryoablation of claim 1, wherein an end of the first conduit adjacent to the first pressure vessel is a first end and an end adjacent to the cryoablation apparatus is a second end;

3. The working medium precooling system for cryoablation according to claim 2, wherein a first output valve is disposed on the first pipeline, the first output valve having an output channel communicated with the inner layer and a feedback channel communicated with the outer layer, and opening and closing of the first output valve controlling opening and closing of the output channel and the feedback channel;

4. The working medium precooling system for cryoablation of claim 3, wherein the first pressure vessel is configured with a first level sensor for acquiring a first current level, and the first output valve is allowed to open when the first current level meets a preset condition.

5. The working medium precooling system for cryoablation of claim 3, wherein a first temperature sensor is disposed on the first conduit adjacent the second end for obtaining a first current temperature of the inner layer;

6. Working medium precooling system for cryoablation as claimed in claim 3, wherein a safety relief valve is provided on an outer layer of the first conduit.

7. The working medium precooling system for cryoablation according to claim 1, wherein during precooling, the liquid-phase cold working medium further enters the cryoablation apparatus from the second end of the inner layer of the first pipeline, the working medium precooling system further includes a seventh pipeline, and the liquid-phase frozen working medium flows through the inner layer of the first pipeline, the cryoablation apparatus, the seventh pipeline in sequence from the first pressure vessel until reaching the second pressure vessel.

8. Working medium precooling system for cryoablation as claimed in claim 7, wherein the second pressure vessel is connected to the first pressure vessel via a fourth conduit, and a controlled element is provided on the fourth conduit, and the controlled element is turned on or off correspondingly under the expected conditions, so that the pressures of the first pressure vessel and the second pressure vessel are balanced.

9. Working medium precooling system for cryoablation as claimed in claim 7, wherein the seventh conduit and the second conduit are connected to the second pressure vessel via a booster pump for boosting the working medium pressure in the seventh conduit and the second conduit prior to delivery to the second pressure vessel.

10. The working medium precooling system for cryoablation as recited in claim 9, wherein a first temperature sensor is disposed on the first conduit adjacent the second end for obtaining a first current temperature of the inner layer;