CN114711944A

CN114711944A - Equipment precooling method for cryoablation

Info

Publication number: CN114711944A
Application number: CN202111642712.XA
Authority: CN
Inventors: 徐宏; 王晓钫; 胡艳艳; 项腾; 肖创业; 吴越
Original assignee: Hangzhou Kunbo Biotechnology Co Ltd
Current assignee: Hangzhou Kunbo Biotechnology Co Ltd
Priority date: 2021-06-30
Filing date: 2021-12-29
Publication date: 2022-07-08
Also published as: CN114719183A; CN114526444A; CN218420016U; CN114504372A; CN114526441A; CN114521953A; CN114636102A; CN114526444B; CN114636102B; CN218075189U; CN114376711A; CN218494750U; CN114526441B; CN114699160A; CN217503347U; CN217960278U

Abstract

The application provides a device precooling method for cryoablation, wherein the device precooling method comprises the following steps: when a first preset condition is met, controlling a first pressure container storing liquid freezing working medium to output the liquid freezing working medium through a first pipeline, wherein the first pipeline is of an internal and external double-layer structure, the liquid freezing working medium passes through two output paths of an inner layer of the first pipeline, the first path passes through a cryoablation device to reach a second pressure container, and the second path passes through an outer layer of the first pipeline to reach the second pressure container; and when the second preset condition is met, pre-cooling is finished and the output of the first pipeline is stopped. Precooling before cryoablation is carried out to reduce the probability of gasification of the working medium due to temperature difference, reduce the gasification amount and avoid the cryoablation failure caused by air blockage.

Description

Equipment precooling method for cryoablation

Technical Field

The application relates to the technical field of medical instruments, in particular to a pre-cooling method for a cryoablation device.

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 cryoablation equipment adopting the liquid refrigerant phase-change cooling method is difficult to solve the problem of air blockage, so that improvement is needed.

Disclosure of Invention

The application discloses an equipment precooling method for cryoablation, which can reduce air blockage probability.

An apparatus pre-cooling method for cryoablation of the present application comprises:

when a first preset condition is met, controlling a first pressure container storing liquid freezing working medium to output the liquid freezing working medium through a first pipeline, wherein the first pipeline is of an internal and external double-layer structure, the liquid freezing working medium passes through two output paths of an inner layer of the first pipeline, the first path passes through a cryoablation device to reach a second pressure container, and the second path passes through an outer layer of the first pipeline to reach the second pressure container;

and when the second preset condition is met, pre-cooling is finished and the output of the first pipeline is stopped.

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

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

Optionally, detecting a first current pressure of the first pressure vessel during the precooling;

and when the first current pressure is lower than the first pressure preset value, outputting the gaseous working medium to the first pressure container through the second pressure container so as to maintain the first current pressure in a first preset pressure range.

Optionally, a fourth electromagnetic valve is arranged between the first pressure vessel and the second pressure vessel, and the fourth electromagnetic valve is opened when the first current pressure is lower than a first preset pressure value until the first current pressure is greater than a third preset pressure value.

Optionally, the fourth electromagnetic valve and the fourth pressure control element are sequentially connected in series between the first pressure vessel and the second pressure vessel, and the output pressure of the fourth pressure control element is set to be greater than the third preset pressure value.

Optionally, the two paths of liquid refrigerant output by the inner layer of the first pipeline are output to the second pressure container through a booster pump;

the equipment precooling method further comprises the following steps:

maintaining a second current pressure within a second preset pressure range through the booster pump in the precooling process; and

and the booster pump is delayed to be closed after precooling is finished.

Optionally, in the pre-cooling process, when the second current pressure of the second pressure vessel reaches a preset pressure value, the booster pump is turned off, and the second current pressure is discharged through a relief valve arranged upstream of the booster pump.

Optionally, the second route is output from the outer layer of the first pipeline and then is sent to the second pressure vessel through the second pipeline;

and when precooling is finished, closing a second electromagnetic valve arranged on the second pipeline.

Optionally, when the pressure of the outer layer of the first pipeline reaches a preset pressure value, the pressure is relieved through a safety relief valve communicated with the outer layer of the first pipeline.

The application also provides a device precooling control device for cryoablation, which comprises a memory, a processor and a computer program stored on the memory, wherein the processor executes the computer program to realize the steps of any one of the device precooling methods for cryoablation.

The present application further provides a computer program product comprising computer instructions which, when executed by a processor, implement the steps of the apparatus pre-cooling method for cryoablation as described in any of the above.

The equipment precooling method for cryoablation can be used for precooling cryoablation equipment more effectively so as to reduce the probability of air blockage.

Drawings

FIG. 1 is a schematic view of a cryoablation system according to the present application;

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 is a schematic diagram of a computer device;

fig. 8 to fig. 13 are method flowcharts, and the connection relationship between the diagrams can refer to the corresponding marks of the boundary portions.

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 obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to 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 use process of the cryoablation equipment, gas blockage occurs due to gasification of low-temperature working medium, so that the gas blockage in the ablation process needs to be reduced.

With reference to fig. 1, the present application provides an apparatus pre-cooling method for cryoablation, comprising:

when a first preset condition is met, controlling a first pressure container (namely a liquid working medium pressure container C1) storing liquid-phase freezing working medium to output the liquid-phase freezing working medium through a first pipeline (namely a liquid refrigerant output pipeline L1), wherein the first pipeline is of an inner-outer double-layer structure, the liquid-phase freezing working medium is output through two paths of an inner layer (namely an inflow channel L1-1-3) of the first pipeline, the first path passes through a cryoablation device (CP) to reach a second pressure container (namely a gaseous working medium pressure container C2), and the second path passes through an outer layer (namely a backflow channel L1-1-2) of the first pipeline to reach the second pressure container;

Compared with the existing cryoablation, the pre-cooling step before the cryoablation is added, the first pipeline and the cryoablation equipment are cooled by the same working medium, so that the temperature difference between the working medium and the first pipeline as well as between the working medium and the cryoablation equipment is reduced when the working medium is cryoablated, the gasification amount is further reduced, and the gas blockage phenomenon is avoided. And in the precooling process, the working medium can be recovered and stored in the second pressure container, so that the environment is protected and the energy is saved. In addition, the outer layer of the first pipeline can also form an isolation layer, the radial heat exchange between the inner layer of the first pipeline and the outside air can be blocked, the temperature of the inner layer is effectively kept, and the time of cryoablation is prolonged.

The first preset condition is that the current liquid level of the first pressure container is within a preset range. The current liquid level of the first pressure vessel is obtained by real-time detection of a liquid level sensor (namely a liquid working medium liquid level sensor C1-2) arranged on the first pressure vessel. The first pipeline extends into the first pressure container and serves as a bottom inserting pipe, the lowest value of the preset range can guarantee normal operation of a precooling process, and sudden flow cutoff during precooling is avoided.

The second preset condition is that the first current temperature of the inner layer of the first pipeline is within a preset range. The first current temperature is detected in real time by a temperature sensor (L1-5) disposed on the first pipe. The temperature sensor is used for detecting one end of the inner layer adjacent to the cryoablation device, wherein the inner layer is cooled finally in the precooling process, and if the position reaches a preset range, other parts of the inner layer also reach the preset range.

The method for precooling in the embodiment further includes detecting a first current pressure of the first pressure vessel in a precooling process, and outputting the gas-phase working medium to the first pressure vessel through the second pressure vessel when the first current pressure is lower than a first pressure preset value so as to maintain the first current pressure within a first preset pressure range. The first current pressure is obtained by a first pressure transmitter (C1-1) arranged on the first pressure vessel. The first working pressure range is that the first pressure container can convey liquid-phase cold working medium through the pressure in the first pressure container, and the first pressure preset value is within the first pressure working range. The two pressure containers are communicated through a fourth pipeline (L4) to realize the pressure compensation of the second pressure container and realize the circulation of the working medium.

In one embodiment, two paths of liquid-phase refrigerant output by the inner layer of the first pipeline are output to the second pressure container through a booster pump (L8-5); the equipment precooling method also comprises the step of maintaining a second current pressure in a second preset pressure range through a booster pump in the precooling process; and delaying the turn-off of the booster pump after the precooling is finished. The lowest value of the second preset pressure range is larger than the maximum value of the first preset pressure range, so that the working medium of the second pressure container can enter the first pressure container and perform pressure compensation.

During the pre-cooling, when the second current pressure of the second pressure vessel reaches the preset pressure value, the booster pump is turned off and discharged through a relief valve (L8-7) disposed upstream of the booster pump. And the second current pressure is prevented from exceeding the rated pressure of the second pressure container, and when the second current pressure is lower than the preset pressure value, the relief valve is closed, and the booster pump is opened again for pressurization.

In one embodiment, the second route is output from the outer layer of the first pipeline and then is transmitted to the second pressure container through the second pipeline; at the end of the pre-cooling, the second solenoid valve (i.e., pre-cooled fluid recovery solenoid valve L2-2) disposed on the second conduit is closed. So that in the following cryoablation process, the liquid-phase freezing working medium only enters the cryoablation equipment.

In one embodiment, when the pressure of the outer layer of the first pipeline reaches a preset pressure value, the pressure is relieved through a safety relief valve communicated with the outer layer of the first pipeline. The safety pressure relief valve (L1-3) prevents the pressure in the liquid refrigerant pipe return channel (L1-1-2) from being too high, and when the pressure is higher than the threshold pressure of the liquid refrigerant pipe return 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 an embodiment, a pre-cooling control device is provided, which may be a computer device, such as a terminal, and its internal structure diagram may be as shown in fig. 7. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected through a system bus, and a computer program stored on the memory. Wherein the processor executes the computer program to implement the above steps.

Additionally, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executable by a processor to implement a method of simulated release of an intratumoral turbulent flow device. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.

In one embodiment, a computer program product is provided comprising computer instructions that when executed by a processor perform the above steps.

According to the working medium precooling method for cryoablation, the pipeline and the equipment through which the working medium flows can be cooled to the same temperature as the working medium before cryoablation, so that the working medium cannot be gasified due to temperature difference during cryoablation, the probability of air blockage is reduced, and the stability and the safety of an operation are improved.

The specific structure of the first pipe and the flow of the working fluid inside, etc. will be described in detail below.

The first pipeline (liquid refrigerant output pipeline L1) is provided with a first end and a second end which are opposite, the first pipeline comprises an outer pipe (L1-1-4) and a separation sleeve (L1-1-5) positioned in the outer pipe, the outer pipe and the separation sleeve form a liquid refrigerant pipe (L1-1), the separation sleeve divides the first pipeline into an inner layer structure and an outer layer structure in the radial direction, the first end of the inner layer (namely the inflow channel L1-1-3) is communicated with a first pressure vessel (C1), the second end of the inner layer (L1-1-3) is communicated with the cryoablation device, the second end of the outer layer (namely the backflow channel L1-1-2) serves as an inflow side and is communicated with the second end of the inner layer, and the first end of the outer layer (L1-1-2) serves as a precooling outflow side.

The conveying device precools when melting, and the flow path of the working medium is two paths: the first path is via the inner layer to the cryoablation device (CP); the second path is via the inflow side of the inner layer (L1-1-3), the outer layer (L1-1-2) up to the precooled outflow side of the outer layer. Wherein two routes all cool the inlayer in the output process, and first way can also cool off the cryoablation equipment, and the second way can also cool off the skin and form the isolation layer and block the inlayer and carry out the heat exchange with the air outside the first pipeline, and this process is continuously carried out until the temperature of inlayer is equal to the output temperature of working medium for follow-up formally carry out the cryoablation during operation, the working medium can not lead to a large amount of gasifications in first pipeline because of the heat exchange, reduces the gas and blocks up.

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 a gas-liquid two-phase flow which flows through the second passage and does not enter the base pipe (L1-1-4-2) of the liquid refrigerant pipe gas-liquid separation device, wherein the liquid content of the mass flow of the part of the two-phase flow is higher than the gas content of the mass flow. 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 refrigerant output valve (L1-2) includes 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, fluid in the liquid refrigerant pipe inflow passage (L1-1-3) of the liquid refrigerant pipe (L1-1) dynamically flows into and out of the first input-output passage. 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; wherein, the precooling outflow side is connected with a control valve (namely a precooling fluid recovery electromagnetic valve L2-2). 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. The liquid cryogen output valve (L1-2) comprises two pairs of input-output channels, the first input-output channel being 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).

And the precooling outflow side is connected with the outer side to the second pressure container for recovery, in the precooling process, the precooling fluid recovery electromagnetic valve (L2-2) is in an open state, and the fluid working medium enters the precooling fluid recovery pipeline (L2) through the liquid refrigerant pipe backflow channel (L1-1-2).

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 vessel C1 is provided with a third pipeline L3 for venting and relieving pressure;

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, a 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).

Delivery device comprising the above-described embodiment, wherein the liquid refrigerant output conduit (first conduit L1) is used for conveying liquid working medium, comprising:

a liquid cryogen tube (L1-1); a liquid refrigerant 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; 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 vessel (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 the rewarming process in the cryoablation procedure, the replacement and rewarming heat exchanger (L6-3) is started to heat the gas working medium in the replacement and rewarming pipe (L6-1) to reach the 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); and a one-way valve (L7-2) of the return gas recovery pipeline is used for avoiding backflow.

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, a 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, so that 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 working flow of the low pressure fluid system is described below with reference to fig. 8 to 13:

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 performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn 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 to relieve pressure until PC1-1_ CP is not larger 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 judging 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 in the OR logic, 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 is then turned off (L8-5).

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; opening a pressure relief solenoid valve (L5-3) of the phase change container, and when the current pressure PL5-2_ CP-atm of a phase change pressure transmitter (L5-2) is less than delta P0& liquid level sensor (C3-4), and the current liquid level value of a liquid level sensor (C3-4) of the phase change pressure container (C3) is less than delta L0, wherein the first liquid level closing threshold LLC3-4_ CV-LLC 3-4_ CL is a first liquid level closing threshold; 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 variable 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 pressure-increasing Lower threshold of 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 re-executing the pressure increase process. Otherwise, the heating is continued until the above certain judgment condition appears.

When the device meets the requirement that the current pressure of the variable pressure transmitter (L5-2) is less than delta P0, and the current temperature TC3-5_ CT acquired by the temperature sensor (C3-5) is more than or equal to the first high temperature threshold or the third pressurization closing threshold PC3_ PB _ CV-PL5-2_ CP of the TC3-5_ Upper Limit temperature sensor (C3-5), an output program is executed. And (3) 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 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.

To prevent the pressure in the phase change pressure vessel C3 from going high at rest, a pressure relief decision is introduced: the current pressure PL5-2_ CP-PC3_ RP _ OV of the phase change pressure transmitter (L5-2) is less than delta P0 of a third decompression opening threshold value of a phase change pressure container (C3), a phase change container decompression electromagnetic valve (L5-3) is opened, and when the current pressure PL5-2_ CP-PC3_ RP _ CV of the phase change pressure transmitter (L5-2) is less than delta P0 of the third decompression closing threshold value of the phase change pressure container (C3), the phase change container decompression 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:

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, and 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

Corresponding to the lower limit of the temperature range and 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; the gas working medium recovery release valve (L8-7) is opened.

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). 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. An apparatus pre-cooling method for cryoablation, comprising:

2. The apparatus pre-cooling method for cryoablation according to claim 1, wherein the first predetermined condition is a current fluid level of the first pressure vessel being within a predetermined range.

3. The apparatus pre-cooling method for cryoablation according to claim 1, wherein the second predetermined condition is a first current temperature of the inner layer of the first conduit being within a predetermined range.

4. The apparatus pre-cooling method for cryoablation according to claim 1, further comprising sensing a first current pressure of the first pressure vessel during the pre-cooling;

5. The apparatus pre-cooling method for cryoablation according to claim 4, wherein a fourth solenoid valve is disposed between the first pressure vessel and the second pressure vessel, and the fourth solenoid valve is opened when the first current pressure is lower than a first preset pressure value until the first current pressure is higher than a third preset pressure value.

6. The apparatus pre-cooling method for cryoablation according to claim 5, wherein a fourth solenoid valve and a fourth pressure control element are connected in series between the first pressure vessel and the second pressure vessel, and an output pressure of the fourth pressure control element is set to be greater than the third preset pressure value.

7. The pre-cooling method for the cryoablation apparatus as claimed in claim 4, wherein the two paths of liquid refrigerant output from the inner layer of the first pipeline are output to the second pressure vessel via a booster pump;

the equipment precooling method further comprises the following steps:

and the booster pump is delayed to be closed after the precooling is finished.

8. The apparatus for pre-cooling cryoablation of claim 7, wherein during pre-cooling, when the second current pressure of the second pressure vessel reaches a preset pressure value, the booster pump is turned off and vented through a relief valve disposed upstream of the booster pump.

9. The apparatus pre-cooling method for cryoablation according to claim 1, wherein the second route is output from the outer layer of the first pipeline and then is output to the second pressure vessel through the second pipeline;

10. The pre-cooling method for cryoablation apparatus according to claim 1, wherein when the pressure in the outer layer of the first conduit reaches a predetermined pressure value, the pressure is released through a safety relief valve connected to the outer layer of the first conduit.