Composite high and low temperature cold and hot ablation system

Abstract

The invention relates to a combined type high-low temperature cold and hot ablation system, and relates to the technical field of ablation. According to the combined type high-low temperature cold and hot ablation system, the pressure of the working medium storage tank is adjusted through the number and the diameter of the ablation needles communicated in the connecting pipeline, the opening degree of the phase separation valve is adjusted to enable the phase separation valve to be kept at the target temperature, and therefore the temperature of the phase separation valve can be adjusted under the combination mode of various ablation needles. And the purpose of rapid cooling is achieved in a mode of saving the consumption of the working medium to the greatest extent.

Description

[0001] This application is a divisional application of Chinese patent CN 202411472318.X, whose application date is October 22, 2024 and whose name is "Composite high and low temperature cold and hot ablation system and its control method". Technical Field

[0002] The present invention relates to the technical field of ablation, and in particular to a composite high-low temperature cold and hot ablation system. Background Art

[0003] The composite high-low temperature cold and hot ablation system can generally include a working fluid storage tank, a connecting pipeline and an ablation needle. After the composite high-low temperature cold and hot ablation system is precooled, the working fluid in the working fluid storage tank can be transported to the ablation needle through the connecting pipeline, and the ablation needle can perform the ablation operation. Since the number of ablation needles connected in the connecting pipeline and the diameter of the ablation needle will affect the flow of the working fluid in the ablation needle, and then affect the temperature of the working fluid, the time required for precooling and ablation operations, the consumption of working fluid and the effect of the ablation operation are completely different. Summary of the invention

[0004] The present invention provides a composite high-low temperature cold and hot ablation system, which can achieve the purpose of rapid cooling in a manner that saves the consumption of working fluid the most under various combinations of ablation needles.

[0005] According to a first aspect of the present invention, the present invention provides a composite high-low temperature cold and hot ablation system, comprising a working fluid storage tank, a phase separation valve, a connecting pipeline, an ablation needle and a controller, wherein the connecting pipeline is used to connect with the working fluid storage tank, the phase separation valve and the ablation needle, and the controller is respectively connected with the working fluid storage tank, the phase separation valve and the ablation needle;

[0006] Wherein, the controller is configured to perform the following steps:

[0007] 100: Determine whether the number of ablation needles connected in the connection pipeline is 0, if yes, execute step 200, if no, execute step 300;

[0008] 200: adjusting the pressure of the working fluid storage tank from P3 to P1-ΔP2, and maintaining the phase separation valve at a target temperature of T3 to T4;

[0009] 300: Determine whether the number of ablation needles connected in the connecting pipeline is 1, if yes, execute step 400, if no, execute step 500;

[0010] 400: Determine whether the diameter of the ablation needle connected in the connecting pipeline is ≥ d1. If so, adjust the pressure of the working fluid storage tank to P1 and keep the phase separation valve at the target temperature T3 to T4. If not, execute step 401;

[0011] 401: Determine whether the diameter of the ablation needle connected in the connecting pipeline is between d2 and d1. If so, adjust the pressure of the working fluid storage tank to P2 and keep the phase separation valve at the target temperature T3 to T4. If not, execute step 402;

[0012] 402: Determine whether the diameter of the ablation needle connected in the connecting pipeline is less than d2. If so, adjust the pressure of the working fluid storage tank to P3, and maintain the phase separation valve at a target temperature between T1 and T2;

[0013] 500: Determine whether the diameter of the ablation needle connected in the connecting pipeline is ≥ d2. If so, adjust the pressure of the working fluid storage tank to P1 and keep the phase separation valve at the target temperature T3 to T4. If not, execute step 501;

[0014] 501: Determine whether the diameter of the ablation needle connected in the connecting pipeline is less than d2. If so, adjust the pressure of the working fluid storage tank to P2, and maintain the phase separation valve at a target temperature of T2 to T3;

[0015] Among them, ΔP2<P1<P2<P3; T1<T2<T3<T4.

[0016] In one embodiment, in step S400 or S500, when the pressure of the working fluid storage tank is adjusted to P1:

[0017] If the pressure of the working fluid storage tank is less than P1-ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank;

[0018] If the pressure of the working fluid storage tank is between P1-ΔP2 and P1+ΔP2, the controller gradually closes the boost valve on the working fluid storage tank;

[0019] If the pressure of the working fluid storage tank is greater than P1+ΔP2, the controller gradually opens the air release valve on the working fluid storage tank;

[0020] If the pressure of the working fluid storage tank is less than P1-ΔP1, the controller completely closes the air release valve on the working fluid storage tank, so that the controller adjusts the pressure of the working fluid storage tank to P1;

[0021] Wherein, P1 is the pressure of the working fluid storage tank, ΔP1 and ΔP2 are respectively the pressure changes of the working fluid storage tank, and ΔP1<ΔP2.

[0022] In one embodiment, in step S200, step S400, step 401 or step S500, when the target temperature of the phase separation valve is between T3 and T4:

[0023] If the current temperature of the phase separation valve is ≥ T5, the controller adjusts the opening of the phase separation valve to 100%;

[0024] If T4≤the current temperature of the phase separation valve<T5, the controller adjusts the opening of the phase separation valve to K3.

[0025] If T3≤the current temperature of the phase separation valve<T4, the controller adjusts the opening of the phase separation valve to K4, wherein K4>K3;

[0026] If the current temperature of the phase separation valve is ≤ T3, the controller adjusts the opening of the phase separation valve to 0%, wherein T3<T4<T5

[0027] Wherein, k is a constant, and its value range is 1≤k≤1.2.

[0028] In one embodiment, K3 and K4 satisfy the following expressions respectively:

[0029]

[0030] In one embodiment, in step 401, when the pressure of the working fluid storage tank is adjusted to P2:

[0031] If the pressure of the working fluid storage tank is less than P2-ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank;

[0032] If the pressure of the working fluid storage tank is between P2-ΔP2 and P2+ΔP2, the controller gradually closes the boost valve on the working fluid storage tank;

[0033] If the pressure of the working fluid storage tank is greater than P2-ΔP2, the controller gradually opens the air release valve on the working fluid storage tank;

[0034] If the pressure of the working fluid storage tank is less than P2-ΔP1, the controller completely closes the air release valve on the working fluid storage tank, so that the controller adjusts the pressure of the working fluid storage tank to P2;

[0035] Wherein, ΔP1 and ΔP2 are respectively the pressure changes of the working fluid storage tank, and ΔP1<ΔP2.

[0036] In one embodiment, in step 501, when the phase separation valve is maintained at the target temperature T2 to T3:

[0037] If the current temperature of the phase separation valve is ≥ T3, the controller adjusts the opening of the phase separation valve to 100%;

[0038] If T2≤the current temperature of the phase separation valve<T3, the controller adjusts the opening of the phase separation valve to K2;

[0039] If the current temperature of the phase separation valve is less than T2, the controller adjusts the opening of the phase separation valve to 0%, wherein T2 is less than T3;

[0040] Among them, K2 satisfies the following expression:

[0041]

[0042] k is a constant, and its value range is 1≤k≤1.2.

[0043] In one embodiment, in step 402, when the pressure of the working fluid storage tank is adjusted to P3:

[0044] If the pressure of the working fluid storage tank is less than P3-2ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank;

[0045] If the pressure of the working fluid storage tank is between P3-2ΔP2 and P3-ΔP2, the controller gradually closes the boost valve on the working fluid storage tank;

[0046] If the pressure of the working fluid storage tank is greater than P3-ΔP2, the controller gradually opens the air release valve on the working fluid storage tank;

[0047] If the pressure of the working fluid storage tank is less than P3-ΔP3, the controller completely closes the air release valve on the working fluid storage tank; thus, the controller adjusts the pressure of the working fluid storage tank to P3;

[0048] Among them, P1, P2, and P3 are the pressures of the working fluid storage tank respectively, and P1<P2<P3; ΔP1, ΔP2, and ΔP3 are the pressure changes of the working fluid storage tank respectively, and ΔP1<ΔP2<ΔP3.

[0049] In one embodiment, in step 402, when the phase separation valve is maintained at the target temperature T1 to T2:

[0050] If the current temperature of the phase separation valve is ≥ T2, the controller adjusts the opening of the phase separation valve to 100%;

[0051] If T1≤the current temperature of the phase separation valve<T2, the controller adjusts the opening of the phase separation valve to K1;

[0052] If the current temperature of the phase separation valve is less than T1, the controller adjusts the opening of the phase separation valve to 0%, wherein T1 is less than T2;

[0053] Among them, K1 satisfies the following expression:

[0054]

[0055] k is a constant, and its value range is 1≤k≤1.2.

[0056] In one embodiment, in step 200, when the pressure of the working fluid storage tank is adjusted from P3 to P1-ΔP2:

[0057] If the pressure of the working fluid storage tank is less than P1-2ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank;

[0058] If the pressure of the working fluid storage tank is between P1-2ΔP2 and P1, the controller gradually closes the boost valve on the working fluid storage tank;

[0059] If the pressure of the working fluid storage tank is greater than P1, the controller gradually opens the air release valve on the working fluid storage tank;

[0060] If the pressure of the working fluid storage tank is less than P1-ΔP3, the air release valve on the working fluid storage tank is completely closed, so that the controller adjusts the pressure of the working fluid storage tank to P1-ΔP2;

[0061] Wherein, P2 and P3 are respectively the pressures of the working fluid storage tank, ΔP3 is the pressure change of the working fluid storage tank, ΔP1<ΔP2<ΔP3<P1<P3.

[0062] In one embodiment, P1 is 650 kPa, P2 is 850 kPa, P3 is 1000 kPa, ΔP1 is 5 KPa to 30 kPa, ΔP2 is 10 KPa to 50 kPa, and ΔP3 is 30 kPa to 80 kPa.

[0063] Compared with the prior art, the advantage of the present invention is that the controller connects the number and diameter of the ablation needles connected in the pipeline to adjust the pressure of the working fluid storage tank and the opening of the phase separation valve so that the phase separation valve is maintained at the target temperature, thereby achieving the purpose of rapid cooling in a way that saves the most working fluid consumption under various combinations of ablation needles. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the accompanying drawings.

[0065] Figure 1 is a flow chart of a control method of a composite high-low temperature cold and hot ablation system in an embodiment of the present invention;

[0066] Figure 2 yes Figure 1 Flowchart of step 200;

[0067] Figure 3 yes Figure 1 Flowchart of step 403;

[0068] Figure 4 yes Figure 1 Flowchart of step 404;

[0069] Figure 5 yes Figure 1 Flowchart of step 405;

[0070] Figure 6 yes Figure 1 Flowchart of step 502 in FIG. DETAILED DESCRIPTION

[0071] The present invention will be further described below in conjunction with the accompanying drawings.

[0072] The present invention provides a composite high-low temperature cold and hot ablation system, including a working fluid storage tank, a phase separation valve, a connecting pipeline, an ablation needle and a controller. The connecting pipeline is used to connect with the working fluid storage tank, the phase separation valve and the ablation needle, and the controller is respectively connected with the working fluid storage tank, the phase separation valve and the ablation needle.

[0073] The working fluid storage tank of the present invention can be, for example, a cold tank for storing cold working fluids such as liquid nitrogen, and its structure can adopt various implementation methods in the prior art. Similarly, the phase separation valve, connecting pipeline and ablation needle can all adopt various implementation methods in the prior art.

[0074] The controller of the present invention is configured to adjust the pressure of the working fluid storage tank according to the number of ablation needles connected in the connecting pipeline and the diameters of the ablation needles connected in the connecting pipeline.

[0075] The idea of ​​the present invention is to design different thresholds according to different ablation needle diameters and number combinations, so as to achieve the purpose of rapid cooling in a way that saves the most working fluid (such as liquid nitrogen) regardless of how the ablation needles are used in combination. Specifically, when the number of ablation needles connected in the connecting pipeline is 1, it is divided into the following three situations.

[0076] The first case is: the number of ablation needles connected in the connecting tube is 1 and the diameter of the ablation needle is ≥ d1. Where d1 may be 2.6 mm, for example. The diameter of the ablation needle connected in the connecting tube is ≥ d1, which means that the diameter of the ablation needle connected in the connecting tube may be 2.6 mm or larger.

[0077] It should be noted that the diameter of the ablation needle refers to the diameter at the exit of the needle tip of the ablation needle.

[0078] In the first case mentioned above, the controller is configured to control the pressure-increasing valve and / or the air-release valve on the working fluid storage tank, so as to adjust the pressure of the working fluid storage tank to P1.

[0079] The controller controls the opening or closing of the boost valve on the working fluid storage tank, or controls the gradual opening or closing of the air release valve on the working fluid storage tank, thereby achieving the purpose of adjusting the pressure (working pressure) of the working fluid storage tank. The boost valve and the air release valve can be electrically connected to the controller, for example, and the controller is configured to send relevant instructions to the boost valve or the air release valve, so that the relevant components on the boost valve or the air release valve perform corresponding actions, thereby adjusting the opening of the boost valve or the air release valve, for example, fully opening the boost valve or the air release valve (i.e., the opening is 100%), fully closing the boost valve or the air release valve (i.e., the opening is 0%), etc.

[0080] For example, in the first case, the controller is constructed such that when the pressure of the working fluid storage tank is less than P1-ΔP2, the controller controls the boost valve to be fully opened and controls the bleed valve to be fully closed; when the pressure of the working fluid storage tank is between P1-ΔP2 and P1+ΔP2, the controller controls the boost valve to be gradually closed (at this time the bleed valve is fully closed); when the pressure of the working fluid storage tank is greater than P1+ΔP2, the controller controls the bleed valve to be gradually opened; when the pressure of the working fluid storage tank is less than P1-ΔP1, the controller controls the bleed valve to be fully closed, thereby adjusting the pressure of the working fluid storage tank to P1; wherein, ΔP1<ΔP2.

[0081] More specifically, P1 can be 650kPa, for example, and P2 can be 850kPa, for example, the value range of ΔP1 can be 5Kpa to 30kPa, and the value range of ΔP2 can be 10Kpa to 50kPa. The smaller the values ​​of ΔP1 and ΔP2, the higher the accuracy of the adjustment. Optionally, ΔP1 is 30kPa and ΔP2 is 50kPa; or optionally, ΔP1 is 10kPa and ΔP2 is 30kPa; or optionally, ΔP1 is 5Kpa and ΔP2 is 10Kpa. In the first case, the target pressure of the working fluid storage tank is 650kPa. At this target pressure, the temperature fed back by the phase separation valve can reach the target temperature within 10 minutes, which is much less than the preparation time before the ablation operation, thereby improving the efficiency of the ablation operation.

[0082] The following description will be given by taking ΔP1 as 30 kPa and ΔP2 as 50 kPa as an example.

[0083] It can be understood that in the first case, the target pressure is P1 (650 kPa), P1-ΔP2 is 600 kPa, P1+ΔP2 is 700 kPa, and P1-ΔP1 is 620 kPa.

[0084] When the pressure of the working fluid storage tank is less than 600kPa, the controller controls the boost valve to be fully opened and controls the air release valve to be fully closed. At this time, the working fluid storage tank can be pressurized to increase its pressure; when the pressure of the working fluid storage tank is between 600kPa-700kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 700kPa, the controller controls the air release valve to be gradually opened. At this time, the working fluid storage tank can be depressurized to reduce its pressure; when the pressure of the working fluid storage tank is less than 620Pa, the controller controls the air release valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 650kPa.

[0085] In the above adjustment process, if the pressure of the working fluid storage tank is between 600kPa and 700kPa, it means that it is close to the target pressure, so the controller can control the boost valve to close gradually so as to gradually approach the target temperature. That is to say, when adjusting the pressure of the working fluid storage tank, the pressure of the working fluid storage tank is not directly compared with the target pressure, but its pressure is compared with the lower limit value (e.g. 600kPa) and the upper limit value (e.g. 700kPa) of the range where the target pressure is located. In this way, considering that both boosting and depressurizing require a certain amount of time, it can ensure that the pressure of the working fluid storage tank gradually approaches the target temperature, and the boost valve or the air release valve will not be frequently opened / closed to cause system disorder.

[0086] The second case is: the number of ablation needles connected in the connecting pipeline is 1 and the diameter of the ablation needle is between d2 and d1. Wherein, d2 may be 2 mm, for example, and the diameter of the ablation needle connected in the connecting pipeline is between d2 and d1, which means that the diameter of the ablation needle connected in the connecting pipeline may be 2 mm or 2.5 mm, etc.

[0087] In the second case above, the controller is configured to control the pressure-increasing valve and / or the air-release valve on the working fluid storage tank, so as to adjust the pressure of the working fluid storage tank to P2, wherein P1<P2.

[0088] The controller controls the opening or closing of the boost valve on the working fluid storage tank, or controls the gradual opening or closing of the vent valve on the working fluid storage tank, thereby achieving the purpose of regulating the pressure (working pressure) of the working fluid storage tank.

[0089] For example, in the second case, the controller is constructed to control the boost valve to be fully opened and the bleed valve to be fully closed when the pressure of the working fluid storage tank is less than P2-ΔP2; to control the boost valve to be gradually closed when the pressure of the working fluid storage tank is between P2-ΔP2 and P2+ΔP2; to control the bleed valve to be gradually opened when the pressure of the working fluid storage tank is greater than P2-ΔP2; to control the bleed valve to be gradually opened; and to control the bleed valve to be fully closed when the pressure of the working fluid storage tank is less than P2-ΔP1, thereby adjusting the pressure of the working fluid storage tank to P2; wherein, ΔP1<ΔP2.

[0090] More specifically, d2 may be, for example, 2 mm, and P2 may be, for example, 850 kPa.

[0091] It can be understood that in the second case, the target pressure is P2 (850 kPa), P2-ΔP2 is 800 kPa, P2+ΔP2 is 900 kPa, and P2-ΔP1 is 820 kPa.

[0092] That is to say, in the second case, the target pressure of the working fluid storage tank is 850kPa. When the pressure of the working fluid storage tank is less than 800kPa, the controller controls the boost valve to be fully opened and controls the bleed valve to be fully closed. At this time, the working fluid storage tank can be pressurized to increase its pressure; when the pressure of the working fluid storage tank is between 800kPa-900kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 800kPa, the controller controls the bleed valve to be gradually opened. At this time, the working fluid storage tank can be depressurized to reduce its pressure; when the pressure of the working fluid storage tank is less than 820Pa, the controller controls the bleed valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 850kPa.

[0093] In the above adjustment process, if the pressure of the working fluid storage tank is between 800kPa and 900kPa, it means that it is close to the target pressure, so the controller can control the boost valve to close gradually so as to gradually approach the target temperature. That is to say, when adjusting the pressure of the working fluid storage tank, the pressure of the working fluid storage tank is not directly compared with the target pressure, but its pressure is compared with the lower limit value (e.g. 800kPa) and the upper limit value (e.g. 900kPa) of the range where the target pressure is located. In this way, considering that both boosting and depressurizing require a certain amount of time, it can ensure that the pressure of the working fluid storage tank gradually approaches the target temperature, and the boost valve or the air release valve will not be frequently opened / closed to cause system disorder.

[0094] The third case is: the number of ablation needles connected in the connecting line is 1 and the diameter of the ablation needle is less than d2, where d2 may be 2 mm, for example. The diameter of the ablation needle connected in the connecting line is less than d2, which means that the diameter of the ablation needle connected in the connecting line may be 1.7 mm.

[0095] In the third case above, the controller adjusts the pressure of the working fluid storage tank to P3.

[0096] The controller controls the opening or closing of the boost valve on the working fluid storage tank, or controls the gradual opening or closing of the vent valve on the working fluid storage tank, thereby achieving the purpose of regulating the pressure (working pressure) of the working fluid storage tank.

[0097] For example, in the third case, when the pressure of the working fluid storage tank is less than P3-2ΔP2, the boost valve is controlled to be fully opened and the bleed valve is controlled to be fully closed; when the pressure of the working fluid storage tank is between P3-3ΔP2 and P3-ΔP2, the boost valve is controlled to be gradually closed; when the pressure of the working fluid storage tank is greater than P3-ΔP2, the bleed valve is controlled to be gradually opened; when the pressure of the working fluid storage tank is less than P3-ΔP3, the bleed valve is controlled to be fully closed, thereby adjusting the pressure of the working fluid storage tank to P2; wherein, P1<P2<P3; ΔP1<ΔP2<ΔP3.

[0098] More specifically, P3 may be, for example, 1000 kPa, and the value range of ΔP3 may be, for example, 30 kPa to 80 kPa. Optionally, ΔP3 is 80 kPa, ΔP3 is 50 kPa; or ΔP3 is 30 kPa.

[0099] That is to say, in the third case, the target pressure of the working fluid storage tank is 1000kPa. When the pressure of the working fluid storage tank is less than 900kPa, the controller controls the boost valve to be fully opened and controls the bleed valve to be fully closed. At this time, the working fluid storage tank can be pressurized to increase its pressure; when the pressure of the working fluid storage tank is between 850kPa-950kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 950kPa, the controller controls the bleed valve to be gradually opened. At this time, the working fluid storage tank can be depressurized to reduce its pressure; when the pressure of the working fluid storage tank is less than 920Pa, the controller controls the bleed valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 1000kPa.

[0100] In the above adjustment process, since the maximum pressure of the working fluid storage tank is set to 1000 kPa, the lower limit value of the range of its target pressure may be 850 kPa, and the upper limit value (not exceeding the maximum pressure) may be 950 kPa.

[0101] Similarly, if the pressure of the working fluid storage tank is between 850kPa and 950kPa, it indicates that it is close to the target pressure, so the controller can control the boost valve to close gradually so as to gradually approach the target temperature. That is to say, when adjusting the pressure of the working fluid storage tank, the pressure of the working fluid storage tank is not directly compared with the target pressure, but its pressure is compared with the lower limit value (e.g. 850kPa) and the upper limit value (e.g. 950kPa) of the range where the target pressure is located. In this way, considering that both boosting and depressurizing require a certain amount of time, the pressure of the working fluid storage tank can be ensured to gradually approach the target temperature, and the boost valve or the air release valve will not be frequently opened / closed to cause system disorder.

[0102] According to the first, second and third cases mentioned above, when the number of ablation needles connected in the connecting pipeline is the same, the smaller the diameter of the ablation needle, the higher the pressure of the working fluid storage tank needs to be adjusted to ensure that the temperature of the cold working fluid at the outlet of the needle tip of each diameter of the ablation needle can meet the treatment temperature requirements.

[0103] In addition, when the number of ablation needles connected in the connecting pipeline is greater than or equal to 2, it is divided into the following fourth case and fifth case.

[0104] The fourth case is: the number of ablation needles connected in the connecting pipeline is ≥ 2 and the diameter of the ablation needle is ≥ d2. In the fourth case, the controller is configured to control the boost valve and / or the deflation valve on the working fluid storage tank to adjust the pressure of the working fluid storage tank to P1.

[0105] For the fourth case, the controller may use the same control method as in the first case to adjust the pressure of the working fluid storage tank to P1, which will not be described in detail in the present invention.

[0106] The fifth situation is: when the number of ablation needles connected in the connecting pipeline is ≥2 and the diameter of the ablation needle is <d2, the controller controls the boost valve and / or the purge valve on the working fluid storage tank to adjust the pressure of the working fluid storage tank to P2; wherein, P1 < P2.

[0107] For the fifth case, the controller may use the same control method as in the second case to adjust the pressure of the working fluid storage tank to P2, which will not be described in detail in the present invention.

[0108] According to the fourth and fifth cases mentioned above, when the number of ablation needles connected in the connecting pipeline is the same, the smaller the diameter of the ablation needle, the higher the pressure of the working fluid storage tank needs to be adjusted to ensure that the temperature of the cold working fluid at the outlet of the needle tip of each diameter of the ablation needle can meet the treatment temperature requirements.

[0109] In addition, for the case where the number of ablation needles connected in the connecting pipeline is 0, that is, the sixth case, the control method of the controller is as follows.

[0110] The controller is constructed such that when the number of ablation needles connected in the connecting pipeline is 0, the controller controls the boost valve and / or the purge valve on the working fluid storage tank, thereby adjusting the pressure of the working fluid storage tank from P3 to P1-ΔP2, that is, the target pressure is P1-ΔP2. Since the number of ablation needles connected in the connecting pipeline is 0, that is, no ablation needles are connected, indicating that the preparation work before the ablation operation is in progress, in this case, the pressure of the working fluid storage tank can be adjusted to a smaller pressure range to avoid wasting the working fluid (liquid nitrogen).

[0111] When the pressure of the working fluid storage tank is less than P1-2ΔP2, the boost valve is controlled to be fully opened and the bleed valve is controlled to be fully closed; when the pressure of the working fluid storage tank is between P1-2ΔP2 and P1, the boost valve is controlled to be gradually closed (the bleed valve is fully closed at this time); when the pressure of the working fluid storage tank is greater than P1, the bleed valve is controlled to be gradually opened; when the pressure of the working fluid storage tank is less than P1-ΔP3, the bleed valve is controlled to be fully closed, thereby adjusting the pressure of the working fluid storage tank to P1-2ΔP2. ΔP1<ΔP2<ΔP3<P1<P3.

[0112] It can be understood that in the sixth case, the target pressure is P1-ΔP2 (600 kPa), P1-2ΔP2 is 550 kPa, and P1-ΔP3 is 570 kPa.

[0113] More specifically, in the sixth case, since the ablation needle is not connected to the connecting pipeline, it means that the ablation operation is not performed at this time, but a pre-cooling operation is performed. Therefore, in the pre-cooling operation, it is necessary to control the target pressure of the working fluid storage tank to be smaller, so as to achieve the purpose of reducing liquid nitrogen consumption.

[0114] That is to say, in the sixth case, the target pressure of the working fluid storage tank is 600kPa. When the pressure of the working fluid storage tank is less than 550kPa, the controller controls the boost valve to be fully opened and controls the air release valve to be fully closed. At this time, the working fluid storage tank can be pressurized to increase its pressure; when the pressure of the working fluid storage tank is between 550kPa-650kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 650kPa, the controller controls the air release valve to be gradually opened. At this time, the working fluid storage tank can be depressurized to reduce its pressure; when the pressure of the working fluid storage tank is less than 570kPa, the controller controls the air release valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 600kPa.

[0115] In the above adjustment process, if the pressure of the working fluid storage tank is between 550kPa-650kPa, it means that it is close to the target pressure, so the controller can control the boost valve to close gradually so as to gradually approach the target temperature. That is to say, when adjusting the pressure of the working fluid storage tank, the pressure of the working fluid storage tank is not directly compared with the target pressure, but its pressure is compared with the lower limit value (e.g. 550kPa) and the upper limit value (e.g. 650kPa) of the range where the target pressure is located. In this way, considering that both boosting and depressurizing require a certain amount of time, it can ensure that the pressure of the working fluid storage tank gradually approaches the target temperature, and the boost valve or the air release valve will not be frequently opened / closed to cause system disorder.

[0116] In all the above cases, the controller controls the opening and closing of the boost valve and the bleed valve through PID regulation, so that the pressure of the working fluid storage tank can gradually approach the target temperature. For example, controlling the boost valve to gradually close or controlling the bleed valve to gradually open can be achieved by PID regulating the opening of the boost valve or the opening of the bleed valve. For example, the opening of the boost valve is adjusted from 100% to 80%, then to 10%, and finally to 0%; or the opening of the bleed valve is adjusted from 0% to 20%, then to 70%, and finally to 100%.

[0117] In the above-mentioned cases, the working fluid storage tank is provided with a pressure detection device for detecting its pressure, such as a pressure sensor, etc. The pressure detection device is electrically connected to the controller, so that the pressure detection device can feed back the pressure of the working fluid storage tank to the controller, and the controller adopts the corresponding control strategy described above according to the pressure of the working fluid storage tank fed back by the pressure detection device.

[0118] In the second aspect of the present invention, the present invention provides a composite high and low temperature hot and cold ablation system, including a working fluid storage tank, a phase separation valve, a connecting pipeline, an ablation needle and a controller. The connecting pipeline is used to connect with the working fluid storage tank, the phase separation valve and the ablation needle, and the controller is respectively connected to the working fluid storage tank, the phase separation valve and the ablation needle.

[0119] The working fluid storage tank of the present invention can be, for example, a cold tank for storing cold working fluids such as liquid nitrogen, and its structure can adopt various implementation methods in the prior art. Similarly, the phase separation valve, connecting pipeline and ablation needle can all adopt various implementation methods in the prior art.

[0120] The controller of the present invention is configured to adjust the opening of the phase separation valve according to the number of the ablation needles connected in the connecting pipeline and the diameter of the ablation needles connected in the connecting pipeline so that the phase separation valve is maintained at the target temperature. The phase separation valve can be electrically connected to the controller, for example, and the controller is configured to send relevant instructions to the phase separation valve so that the relevant components on the phase separation valve perform corresponding actions, thereby adjusting the opening of the phase separation valve, for example, making the opening of the phase separation valve 100% or 0%, etc.

[0121] The concept of the present invention is to design different thresholds according to different ablation needle diameters and quantity combinations, so as to achieve the purpose of rapid cooling in the most liquid nitrogen-saving manner regardless of how the ablation needles are combined and used.

[0122] Specifically, when the number of ablation needles connected in the connecting pipeline is 1, it is divided into the following three cases.

[0123] The first case is: the number of ablation needles connected in the connecting tube is 1 and the diameter of the ablation needle is ≥ d1, where d1 can be 2.6 mm, for example. The diameter of the ablation needle connected in the connecting tube is ≥ d1, which means that the diameter of the ablation needle connected in the connecting tube may be 2.6 mm or larger.

[0124] In the first case described above, the controller is configured so that the opening degree of the phase separation valve is adjusted so that the phase separation valve is maintained at the target temperature T3 to T4.

[0125] Specifically, when the current temperature of the phase separation valve is ≥T5, the controller adjusts the opening of the phase separation valve to 100%; when T4≤the current temperature of the phase separation valve<T5, the controller adjusts the opening of the phase separation valve to K3; when T3≤the current temperature of the phase separation valve<T4, the controller adjusts the opening of the phase separation valve to K4, wherein K4>K3; when the current temperature of the phase separation valve is ≤T3, the controller adjusts the opening of the phase separation valve to 0%, wherein T3<T4<T5.

[0126] K3 and K4 satisfy the following expressions respectively:

[0127]

[0128] Wherein, k is a constant, and its value range is 1≤k≤1.2.

[0129] The value of k is an empirical constant summarized and verified based on experimental results, and the value of k is related to the pressure of the working fluid storage tank and the number of ablation needles connected in the connecting pipeline. In the first case, the pressure of the working fluid storage tank is the target pressure P1 (650kPa), and the number of ablation needles connected in the connecting pipeline is 1, so the degree of controller adjustment needs to be greater so that the phase separation valve can be adjusted to the target temperature more quickly, so that the value of k is closer to its maximum value. Therefore, in the first case, the value of k can be 1.15.

[0130] More specifically, T3 is -5°C, T4 is 0°C, and T5 is 10°C. It can be understood that in the first case, the controller is configured to adjust the opening of the phase separation valve so that the phase separation valve is maintained at the target temperature of -5°C to 0°C.

[0131] Among them, when T3 is -5°C, the flow rate of the phase separation valve is 15L / min-18L / min; when T4 is 0°C, the flow rate of the phase separation valve is 10L / min-14L / min; when T5 is 10°C, the flow rate of the phase separation valve is 8L / min~10L / min, which can ensure that the consumption of liquid nitrogen is low.

[0132] Therefore, the controller specifically adjusts the opening of the phase separation valve as follows:

[0133] When the current temperature of the phase separation valve is ≥10℃, the controller adjusts the opening of the phase separation valve to 100%; when 0℃≤the current temperature of the phase separation valve<10℃, the controller adjusts the opening of the phase separation valve to K3, and when -5℃≤the current temperature of the phase separation valve<0℃, the controller adjusts the opening of the phase separation valve to K4, wherein K4>K3, and when the current temperature of the phase separation valve is ≤-5℃, the controller adjusts the opening of the phase separation valve to 0%.

[0134] K3 satisfies the following expression:

[0135]

[0136] K4 satisfies the following expressions respectively:

[0137]

[0138] The second case is: the number of ablation needles connected in the connecting pipeline is 1 and the diameter of the ablation needle is between d2 and d1. Wherein, d2 may be 2 mm, for example, and the diameter of the ablation needle connected in the connecting pipeline is between d2 and d1, which means that the diameter of the ablation needle connected in the connecting pipeline may be 2 mm or 2.5 mm, etc.

[0139] In the second case, the controller adjusts the opening of the phase separation valve to keep the phase separation valve at the target temperature, and the target temperature of the phase separation valve is T3 to T4. It can be understood that in the second case, the controller is configured to adjust the opening of the phase separation valve so that the phase separation valve is maintained at the target temperature of -5°C to 0°C.

[0140] For the second case, the controller can use the same control method as in the first case to adjust the opening of the phase separation valve to keep the phase separation valve at the target temperature. The target temperature of the phase separation valve is T3 to T4, which will not be elaborated in the present invention.

[0141] The third case is: the number of ablation needles connected in the connecting line is 1 and the diameter of the ablation needle is less than d2, where d2 may be 2 mm, for example. The diameter of the ablation needle connected in the connecting line is less than d2, which means that the diameter of the ablation needle connected in the connecting line may be 1.7 mm.

[0142] In the third case, the controller is configured to adjust the opening degree of the phase separation valve to maintain the phase separation valve at a target temperature, and the target temperature of the phase separation valve is T1 to T2.

[0143] Specifically, when the current temperature of the phase separation valve is ≥ T2, the controller adjusts the opening of the phase separation valve to 100%; when T1≤the current temperature of the phase separation valve<T2, the controller adjusts the opening of the phase separation valve to K1; when the current temperature of the phase separation valve is <T1, the controller adjusts the opening of the phase separation valve to 0%, wherein T1<T2; wherein K1 satisfies the following expression:

[0144]

[0145] k is a constant, and its value range is 1≤k≤1.2.

[0146] The value of k is an empirical constant summarized and verified based on experimental results, and the value of k is related to the pressure of the working fluid storage tank and the number of ablation needles connected in the connecting pipeline. In the third case, the pressure of the working fluid storage tank is the target pressure P3 (1000kPa), and the number of ablation needles connected in the connecting pipeline is 1, so the degree of controller adjustment can be slightly smaller than that in the first case. Therefore, in the third case, the value of k can be 1.12.

[0147] More specifically, T1 may be, for example, -15°C, and T2 may be, for example, -10°C. It can be understood that in the third case, the controller is configured to adjust the opening of the phase separation valve so that the phase separation valve is maintained at a target temperature of -15°C to -10°C.

[0148] Therefore, the controller specifically adjusts the opening of the phase separation valve as follows:

[0149] When the current temperature of the phase separation valve is ≥-10°C, the controller adjusts the opening of the phase separation valve to 100%; when -15°C≤the current temperature of the phase separation valve<-10°C, the controller adjusts the opening of the phase separation valve to K1; when the current temperature of the phase separation valve is <-15°C, the controller adjusts the opening of the phase separation valve to 0%, wherein T1<T2; wherein K1 satisfies the following expression:

[0150]

[0151] In addition, when the number of ablation needles connected in the connecting pipeline is greater than or equal to 2, it is divided into the following fourth case and fifth case.

[0152] The fourth case is: the number of ablation needles connected in the connecting pipeline is ≥2 and the diameter of the ablation needle is ≥d2. In the above fourth case, the controller adjusts the opening of the phase separation valve to keep the phase separation valve at the target temperature, and the target temperature of the phase separation valve is T3 to T4. It can be understood that in the above second case, the controller is configured so that the opening of the phase separation valve is maintained at the target temperature of -5°C to 0°C.

[0153] For the fourth case, the controller can use the same control method as in the first case to adjust the opening of the phase separation valve to keep the phase separation valve at the target temperature. The target temperature of the phase separation valve is T3 to T4, which will not be elaborated in the present invention.

[0154] Furthermore, the fifth situation is: when the number of ablation needles connected in the connecting pipeline is ≥2 and the diameter of the ablation needle is < d2.

[0155] In the fifth case, the controller adjusts the opening of the phase separation valve to keep the phase separation valve at the target temperature, and the target temperature of the phase separation valve is T2 to T3. It can be understood that in the above fifth case, the controller is configured so that the opening of the phase separation valve is maintained at the target temperature of -10°C to -5°C.

[0156] For example, in the fifth case, when the current temperature of the phase separation valve is ≥ T3, the controller adjusts the opening of the phase separation valve to 100%; when T2≤the current temperature of the phase separation valve<T3, the controller adjusts the opening of the phase separation valve to K2; when the current temperature of the phase separation valve is<T2, the controller adjusts the opening of the phase separation valve to 0%, wherein T2<T3; wherein K2 satisfies the following expression:

[0157]

[0158] k is a constant, and its value range is 1≤k≤1.2.

[0159] The value of k is an empirical constant summarized and verified based on experimental results, and the value of k is related to the pressure of the working fluid storage tank and the number of ablation needles connected in the connecting pipeline. In the fifth case, the pressure of the working fluid storage tank is the target pressure P2 (850kPa), and the number of ablation needles connected in the connecting pipeline is 2, so the degree of controller adjustment can be smaller than that in the first case. Therefore, in the fifth case, the value of k can be 1.05.

[0160] Therefore, the controller specifically adjusts the opening of the phase separation valve as follows:

[0161] When the current temperature of the phase separation valve is ≥-5°C, the controller adjusts the opening of the phase separation valve to 100%; when -10°C≤the current temperature of the phase separation valve<-5°C, the controller adjusts the opening of the phase separation valve to K2; when the current temperature of the phase separation valve is <-10°C, the controller adjusts the opening of the phase separation valve to 0%, wherein K2 satisfies the following expression:

[0162]

[0163] In addition, for the case where the number of ablation needles connected in the connecting pipeline is 0, that is, the sixth case, the controller is constructed to adjust the opening of the phase separation valve to maintain the phase separation valve at the target temperature when the number of ablation needles connected in the connecting pipeline is 0, and the target temperature of the phase separation valve is T3 to T4.

[0164] For the sixth case, the controller can use the same control method as in the first case to adjust the opening of the phase separation valve to keep the phase separation valve at the target temperature, and the target temperature of the phase separation valve is T3 to T4, which will not be described in detail in the present invention. It can be understood that in the sixth case, the controller is configured so that the opening of the phase separation valve is maintained at the target temperature of -5°C to 0°C.

[0165] It should be noted that the current temperature of the phase separation valve refers to the temperature obtained at the temperature measuring point on the downstream side of the phase separation valve, which is generally the temperature of the gas phase working fluid separated by the phase separation valve (or may also include a small amount of liquid phase working fluid). Therefore, if the current temperature of the phase separation valve is high (for example, greater than 10°C), it means that there is more gas phase in the working fluid at this time, so it is necessary to increase the opening of the phase separation valve to increase the gas velocity of the discharged gas phase.

[0166] In the above-mentioned cases, the value of k is related to the pressure of the working fluid storage tank and the number of ablation needles connected in the connecting pipeline. The lower the pressure of the working fluid storage tank, the larger the value of k; the fewer the number of ablation needles connected in the connecting pipeline, the larger the value of k. The larger the value of k, the greater the degree to which the controller adjusts the opening of the phase separation valve, so that feedback adjustment can be performed more quickly according to the phase separation temperature.

[0167] In the above-mentioned cases, a temperature detection device for detecting the temperature of the phase separation valve is provided on the phase separation valve (or in the pipeline downstream thereof), which may be, for example, a temperature sensor or a thermocouple, etc. The temperature detection device is electrically connected to the controller, so that the temperature detection device can feed back the temperature of the working fluid storage tank to the controller, and the controller adopts the corresponding control strategy described above according to the temperature of the phase separation valve fed back by the temperature detection device.

[0168] In addition, the controller of the present invention can also be constructed to adjust the pressure of the working fluid storage tank and the opening of the phase separation valve according to the number of ablation needles connected in the connecting pipeline and the diameter of the ablation needles connected in the connecting pipeline, so that the pressure of the working fluid storage tank is maintained near the target pressure and the phase separation valve is maintained at the target temperature.

[0169] In a third aspect of the present invention, the present invention provides a control method for a composite high-low temperature cold and hot ablation system. The control method is applied to the composite high-low temperature cold and hot ablation system, and the control method comprises the following steps:

[0170] Step 100: Determine whether the number of ablation needles connected in the connecting pipeline is 0, if so, execute step 200, if not, execute step 300.

[0171] Specifically, feedback can be provided through the connection device on the ablation needle. For example, when the connecting pipeline is connected to the corresponding ablation needle, it indicates that the two are snapped into place, and the connection device will feedback a signal that the ablation needle is connected to the controller, indicating that the ablation needle is connected in the connecting pipeline; otherwise, it indicates that the ablation needle is not connected in the connecting pipeline.

[0172] Step 200: When the number of ablation needles connected in the connecting pipeline is 0 (corresponding to the sixth case described above), the pressure of the working fluid storage tank is adjusted from P3 to P1-ΔP2, and the current temperature of the phase separation valve is maintained at T3 to T4.

[0173] The pressure of the working fluid storage tank is adjusted from P3 to P1-ΔP2, and the current temperature of the phase separation valve is maintained at T3 to T4. The control method in the sixth case mentioned above can be adopted.

[0174] Step 300: When the number of ablation needles connected in the connection pipeline is not 0, further determination is required, that is, determining whether the number of ablation needles connected in the connection pipeline is 1, if so, executing step 400, if not, executing step 500.

[0175] Step 400: For the case where the number of ablation needles connected in the connecting pipeline is 1, further judgment is required. That is, whether the diameter of the ablation needles connected in the connecting pipeline is ≥ d1. If the diameter of the ablation needles connected in the connecting pipeline is ≥ d1 (corresponding to the first case described above), the pressure of the working fluid storage tank is adjusted to P1, and the current temperature of the phase separation valve is maintained at T3 to T4 (i.e., step 403); otherwise, step 401 is executed, which requires further judgment.

[0176] The pressure of the working fluid storage tank is adjusted to P1, and the current temperature of the phase separation valve is maintained at T3 to T4. The control method in the first case mentioned above can be adopted.

[0177] Step 401: Determine whether the diameter of the ablation needle connected in the connecting pipeline is between d2 and d1. If the diameter of the ablation needle connected in the connecting pipeline is between d2 and d1 (corresponding to the second case described above), adjust the pressure of the working fluid storage tank to P2, and maintain the current temperature of the phase separation valve at T3 to T4 (i.e., step 404); otherwise, execute step 402.

[0178] The pressure of the working fluid storage tank is adjusted to P2, and the current temperature of the phase separation valve is maintained at T3 to T4. The control method in the second case mentioned above can be adopted.

[0179] Step 402: Determine whether the diameter of the ablation needle connected in the connecting pipeline is less than d2. If the diameter of the ablation needle connected in the connecting pipeline is less than d2 (corresponding to the third case described above), adjust the pressure of the working fluid storage tank to P3, and maintain the current temperature of the phase separation valve at T1 to T2.

[0180] The pressure of the working fluid storage tank is adjusted to P3, and the current temperature of the phase separation valve is maintained at T1 to T2 (ie, step 405), and the control method in the third case mentioned above can be adopted.

[0181] 500: For the case where the number of ablation needles connected in the connecting pipeline is ≥2, further judgment is required. That is, whether the diameter of the ablation needles connected in the connecting pipeline is ≥d2 is judged. If the diameter of the ablation needles connected in the connecting pipeline is ≥d2 (corresponding to the fourth case described above), the pressure of the working fluid storage tank is adjusted to P1, and the current temperature of the phase separation valve is maintained at T3 to T4 (i.e. step 403); otherwise, step 501 is executed.

[0182] The pressure of the working fluid storage tank is adjusted to P1, and the current temperature of the phase separation valve is maintained at T3 to T4. The control method in the fourth case mentioned above can be adopted.

[0183] 501: Determine whether the diameter of the ablation needle connected in the connecting pipeline is less than d2. If the diameter of the ablation needle connected in the connecting pipeline is less than d2 (corresponding to the fifth case described above), adjust the pressure of the working fluid storage tank to P2, and maintain the current temperature of the phase separation valve at T2 to T3 (i.e., step 502). Among them, ΔP2<P1<P2<P3; T1<T2<T3<T4.

[0184] The pressure of the working fluid storage tank is adjusted to P2, and the current temperature of the phase separation valve is maintained at T2 to T3. The control method in the fifth case mentioned above can be adopted.

[0185] When the precooling operation or the ablation operation is completed, the method can be terminated.

[0186] Example 1

[0187] Connect the disconnected ablation needle in the tubing.

[0188] The target pressure of the working fluid storage tank is 600kPa. When the pressure of the working fluid storage tank is less than 550kPa, the controller controls the boost valve to be fully opened and controls the air release valve to be fully closed; when the pressure of the working fluid storage tank is between 550kPa-650kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 650kPa, the controller controls the air release valve to be gradually opened; when the pressure of the working fluid storage tank is less than 650Pa, the controller controls the air release valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 570kPa.

[0189] During this process, the liquid nitrogen consumption is about 3%, and the duration of the precooling operation of the composite high-low temperature cold and hot ablation system (ie, the time it takes for the composite high-low temperature cold and hot ablation system to drop to the required temperature) is 6 minutes.

[0190] Therefore, when connecting the ablation needle that is not connected in the pipeline, that is, during the pre-cooling process of the system, by controlling the pressure of the working fluid storage tank, the consumption of liquid nitrogen meets the requirement of less than 8% and the pre-cooling time meets the requirement of no more than 8 minutes.

[0191] Example 2

[0192] The number of ablation needles connected in the connecting pipeline is 1.

[0193] The diameter of the ablation needle is 3mm. The target pressure of the working fluid storage tank is 650kPa. When the pressure of the working fluid storage tank is less than 600kPa, the controller controls the boost valve to be fully opened and controls the vent valve to be fully closed; when the pressure of the working fluid storage tank is between 600kPa-700kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 700kPa, the controller controls the vent valve to be gradually opened; when the pressure of the working fluid storage tank is less than 620Pa, the controller controls the vent valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 650kPa.

[0194] When the ablation needle is used for ablation, the liquid nitrogen consumption is about 13%, the ice ball size is about 50 mm (short axis size) × 70 mm (long axis size), and the ablation operation lasts for 20 minutes. It should be noted that the above ice ball size is measured in a 37°C gelatin environment.

[0195] The diameter of the ablation needle is 2.6mm. The target pressure of the working fluid storage tank is 850kPa. When the pressure of the working fluid storage tank is less than 800kPa, the controller controls the boost valve to be fully opened and controls the vent valve to be fully closed; when the pressure of the working fluid storage tank is between 800kPa-900kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 800kPa, the controller controls the vent valve to be gradually opened; when the pressure of the working fluid storage tank is less than 820Pa, the controller controls the vent valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 850kPa.

[0196] When the ablation needle is used for ablation, the liquid nitrogen consumption is about 15%, the ice ball size is about 43mm (short axis size) × 52mm (long axis size), and the ablation operation lasts for 20 minutes. It should be noted that the above ice ball size is measured in a 37°C gelatin environment.

[0197] The diameter of the ablation needle is 1.7mm. The target pressure of the working fluid storage tank is 1000kPa. When the pressure of the working fluid storage tank is less than 900kPa, the controller controls the boost valve to be fully opened and controls the vent valve to be fully closed; when the pressure of the working fluid storage tank is between 850kPa-950kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 950kPa, the controller controls the vent valve to be gradually opened; when the pressure of the working fluid storage tank is less than 920Pa, the controller controls the vent valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 1000kPa.

[0198] When this ablation needle is used for ablation, the liquid nitrogen consumption is about 17%, the ice ball size is about 28mm (short axis size) × 32mm (long axis size), and the ablation operation lasts for 20 minutes. It should be noted that the above ice ball size is measured in a 37°C gelatin environment. Therefore, when the ablation needle is connected in the connecting pipeline, the pressure of the working fluid storage tank is controlled so that the consumption (total amount) of liquid nitrogen meets the requirement of less than 20% (for the minimum diameter of the ablation needle connected in the connecting pipeline).

[0199] Example 3

[0200] The number of ablation needles connected in the connecting pipeline is 2.

[0201] The diameters of the ablation needles are 3mm and 2.6mm. The target pressure of the working fluid storage tank is 650kPa. When the pressure of the working fluid storage tank is less than 600kPa, the controller controls the boost valve to be fully opened and controls the vent valve to be fully closed; when the pressure of the working fluid storage tank is between 600kPa-700kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 700kPa, the controller controls the vent valve to be gradually opened; when the pressure of the working fluid storage tank is less than 620Pa, the controller controls the vent valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 650kPa.

[0202] When the ablation needle is used for ablation, the liquid nitrogen consumption is about 28%, and the ablation operation lasts for 20 minutes.

[0203] The diameters of the ablation needles are 1.7mm and 1.7mm. The target pressure of the working fluid storage tank is 850kPa. When the pressure of the working fluid storage tank is less than 800kPa, the controller controls the boost valve to be fully opened and controls the vent valve to be fully closed; when the pressure of the working fluid storage tank is between 800kPa-900kPa, the controller controls the boost valve to be gradually closed; when the pressure of the working fluid storage tank is greater than 800kPa, the controller controls the vent valve to be gradually opened; when the pressure of the working fluid storage tank is less than 820Pa, the controller controls the vent valve to be fully closed, thereby dynamically adjusting the pressure of the working fluid storage tank to 850kPa.

[0204] When this ablation needle is used for ablation, the liquid nitrogen consumption is about 32%, the ice ball size is about 30mm (short axis 1 size) × 37mm (short axis 2 size) × 46mm (long axis size) (the spacing between the two ablation needles is 10mm), and the ablation operation lasts for 20 minutes. It should be noted that the above ice ball size is measured in a 37°C gelatin environment.

[0205] Therefore, when the ablation needle is connected in the connecting pipeline, the consumption (total amount) of liquid nitrogen basically meets the requirement of less than 30% (for the minimum diameter of the ablation needle connected in the connecting pipeline) by controlling the pressure of the working fluid storage tank.

[0206] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A composite high-low temperature cold and hot ablation system, characterized in that: It includes a working fluid storage tank, a phase separation valve, a connecting pipeline, an ablation needle and a controller, wherein the connecting pipeline is used to connect with the working fluid storage tank, the phase separation valve and the ablation needle, and the controller is connected with the working fluid storage tank, the phase separation valve and the ablation needle respectively; Wherein, the controller is configured to perform the following steps: 100: Determine whether the number of ablation needles connected in the connecting pipeline is 0, if yes, execute step 200, if no, execute step 300; 200: adjusting the pressure of the working fluid storage tank from P3 to P1-ΔP2, and maintaining the phase separation valve at the target temperature T3 to T4; 300: Determine whether the number of ablation needles connected in the connecting pipeline is 1, if yes, execute step 400, if no, execute step 500; 400: Determine whether the diameter of the ablation needle connected in the connecting pipeline is ≥ d1. If so, adjust the pressure of the working fluid storage tank to P1 and keep the phase separation valve at the target temperature T3 to T4. If not, execute step 401; 401: Determine whether the diameter of the ablation needle connected in the connecting pipeline is between d2 and d1. If so, adjust the pressure of the working fluid storage tank to P2 and keep the phase separation valve at the target temperature T3 to T4. If not, execute step 402; 402: Determine whether the diameter of the ablation needle connected in the connecting pipeline is less than d2. If so, adjust the pressure of the working fluid storage tank to P3, and maintain the phase separation valve at the target temperature T1 to T2; 500: Determine whether the diameter of the ablation needle connected in the connecting pipeline is ≥ d2. If so, adjust the pressure of the working fluid storage tank to P1 and keep the phase separation valve at the target temperature T3 to T4. If not, execute step 501; 501: Determine whether the diameter of the ablation needle connected in the connecting pipeline is less than d2. If so, adjust the pressure of the working fluid storage tank to P2, and maintain the phase separation valve at a target temperature of T2 to T3; Among them, ΔP2<P1<P2<P3; T1<T2<T3<T4.

2. The combined high-low temperature cold and hot ablation system according to claim 1, characterized in that: In step S400 or S500, when the pressure of the working fluid storage tank is adjusted to P1: If the pressure of the working fluid storage tank is less than P1-ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is between P1-ΔP2 and P1+ΔP2, the controller gradually closes the boost valve on the working fluid storage tank; If the pressure of the working fluid storage tank is greater than P1+ΔP2, the controller gradually opens the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is less than P1-ΔP1, the controller completely closes the air release valve on the working fluid storage tank, so that the controller adjusts the pressure of the working fluid storage tank to P1; Wherein, P1 is the pressure of the working fluid storage tank, ΔP1 and ΔP2 are respectively the pressure changes of the working fluid storage tank, and ΔP1<ΔP2.

3. The combined high-low temperature cold and hot ablation system according to claim 1 or 2, characterized in that: In step S200, step S400, step 401 or step S500, when the target temperature of the phase separation valve is between T3 and T4: If the current temperature of the phase separation valve is ≥ T5, the controller adjusts the opening of the phase separation valve to 100%; If T4≤the current temperature of the phase separation valve<T5, the controller adjusts the opening of the phase separation valve to K3. If T3≤the current temperature of the phase separation valve<T4, the controller adjusts the opening of the phase separation valve to K4, wherein K4>K3; If the current temperature of the phase separation valve is ≤ T3, the controller adjusts the opening of the phase separation valve to 0%, wherein T3<T4<T5 Wherein, k is a constant, and its value range is 1≤k≤1.

2.

4. The combined high-low temperature cold and hot ablation system according to claim 3, characterized in that: K3 and K4 satisfy the following expressions respectively:

5. The combined high-low temperature cold and hot ablation system according to claim 1 or 2, characterized in that: In step 401, when the pressure of the working fluid storage tank is adjusted to P2: If the pressure of the working fluid storage tank is less than P2-ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is between P2-ΔP2 and P2+ΔP2, the controller gradually closes the boost valve on the working fluid storage tank; If the pressure of the working fluid storage tank is greater than P2-ΔP2, the controller gradually opens the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is less than P2-ΔP1, the controller completely closes the air release valve on the working fluid storage tank, so that the controller adjusts the pressure of the working fluid storage tank to P2; Wherein, ΔP1 and ΔP2 are respectively the pressure changes of the working fluid storage tank, and ΔP1<ΔP2.

6. The combined high-low temperature cold and hot ablation system according to claim 5, characterized in that: In step 501, when the phase separation valve is maintained at the target temperature T2 to T3: If the current temperature of the phase separation valve is ≥ T3, the controller adjusts the opening of the phase separation valve to 100%; If T2≤the current temperature of the phase separation valve<T3, the controller adjusts the opening of the phase separation valve to K2; If the current temperature of the phase separation valve is less than T2, the controller adjusts the opening of the phase separation valve to 0%, wherein T2 is less than T3; Among them, K2 satisfies the following expression: k is a constant, and its value range is 1≤k≤1.

2.

7. The combined high-low temperature cold and hot ablation system according to claim 1 or 2, characterized in that: In step 402, when the pressure of the working fluid storage tank is adjusted to P3: If the pressure of the working fluid storage tank is less than P3-2ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is between P3-2ΔP2 and P3-ΔP2, the controller gradually closes the boost valve on the working fluid storage tank; If the pressure of the working fluid storage tank is greater than P3-ΔP2, the controller gradually opens the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is less than P3-ΔP3, the controller completely closes the air release valve on the working fluid storage tank; thus, the controller adjusts the pressure of the working fluid storage tank to P3; Among them, P1, P2, and P3 are the pressures of the working fluid storage tank respectively, and P1<P2<P3; ΔP1, ΔP2, and ΔP3 are the pressure changes of the working fluid storage tank respectively, and ΔP1<ΔP2<ΔP3.

8. The combined high-low temperature cold and hot ablation system according to claim 7, characterized in that: In step 402, when the phase separation valve is maintained at the target temperature T1 to T2: If the current temperature of the phase separation valve is ≥ T2, the controller adjusts the opening of the phase separation valve to 100%; If T1≤the current temperature of the phase separation valve<T2, the controller adjusts the opening of the phase separation valve to K1; If the current temperature of the phase separation valve is less than T1, the controller adjusts the opening of the phase separation valve to 0%, wherein T1 is less than T2; Among them, K1 satisfies the following expression: k is a constant, and its value range is 1≤k≤1.

2.

9. The combined high-low temperature cold and hot ablation system according to claim 1 or 2, characterized in that: In step 200, when the pressure of the working fluid storage tank is adjusted from P3 to P1-ΔP2: If the pressure of the working fluid storage tank is less than P1-2ΔP2, the controller fully opens the boost valve on the working fluid storage tank and fully closes the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is between P1-2ΔP2 and P1, the controller gradually closes the boost valve on the working fluid storage tank; If the pressure of the working fluid storage tank is greater than P1, the controller gradually opens the air release valve on the working fluid storage tank; If the pressure of the working fluid storage tank is less than P1-ΔP3, the controller completely closes the air release valve on the working fluid storage tank, so that the controller adjusts the pressure of the working fluid storage tank to P1-ΔP2; Wherein, P2 and P3 are respectively the pressures of the working fluid storage tank, ΔP3 is the pressure change of the working fluid storage tank, ΔP1<ΔP2<ΔP3<P1<P3.

10. The combined high-low temperature cold and hot ablation system according to claim 1 or 2, characterized in that: P1 is 650kPa, P2 is 850kPa, P3 is 1000kPa, ΔP1 is 5Kpa~30kPa, ΔP2 is 10Kpa~50kPa, and ΔP3 is 30kPa~80kPa.

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