A radiofrequency ablation system for solid tumors and a radiofrequency parameter control method

Abstract

The present application relates to the field of medical device technology, and specifically to a radiofrequency ablation system for solid tumors and a radiofrequency parameter control method, the method comprising: real-time acquisition of power value, temperature value and pressure value during radiofrequency ablation; based on the difference between the temperature at the end of preheating and the preset target temperature during radiofrequency ablation, and the time required from the start of preheating to the moment when the temperature change trend changes, determine the degree of interference of the temperature of the lesion tissue during the preheating stage; determine the sedimentation influence of the lesion tissue; based on the temperature change amount and pressure change amount at each sampling moment relative to the previous sampling moment in the actual ablation stage, and the difference between the preset target temperature and the temperature value at each sampling moment, determine the ablation intervention degree at each sampling moment; obtain the power value at the next sampling moment during radiofrequency ablation. The present application aims to improve the treatment effect on solid tumors by dynamically controlling the radiofrequency parameters during radiofrequency ablation.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a solid tumor radiofrequency ablation system and a radiofrequency parameter control method. Background Art

[0002] Solid tumors refer to malignant tumors composed of solid tissues, usually formed by abnormal proliferation of epithelial cells. Common solid tumors include lung cancer, colorectal cancer, liver cancer, kidney cancer and breast cancer. Due to contraindications, many tumors are not suitable for direct surgical resection. Therefore, ablation technology is needed to treat tumors, among which radiofrequency ablation (RFA) is the most commonly used technology.

[0003] During the radiofrequency ablation process, the mapping relationship between radiofrequency parameters and heating temperature, that is, the mapping relationship between power and heating temperature, is often relied upon to achieve ablation treatment of tumor cells. Normally, the mapping relationship is fixed, but in the actual process, it is affected by the heat deposition effect of the tumor itself and its surrounding tissues, causing blood flow to take away part of the heat, and the blood circulation in different parts is different, which will lead to deviations in the radiofrequency parameters regulated based on the traditional mapping relationship, resulting in poor treatment effects, and possible recurrence or tissue carbonization. Summary of the invention

[0004] In view of the above, it is necessary to provide a solid tumor radiofrequency ablation system and a radiofrequency parameter control method. Compared with the traditional radiofrequency parameter control method of the radiofrequency ablation system, the radiofrequency parameters in the radiofrequency ablation process are dynamically controlled to improve the treatment effect on solid tumors:

[0005] In a first aspect, an embodiment of the present application provides a method for controlling radio frequency parameters of a solid tumor radiofrequency ablation system, the method comprising the following steps:

[0006] Real-time acquisition of power, temperature and pressure values ​​during radiofrequency ablation of solid tumors;

[0007] Based on the difference between the temperature at the end of preheating and the preset target temperature during the radiofrequency ablation process, and the time required from the start of preheating to the moment when the temperature change trend changes, the degree of interference with the temperature of the lesion tissue during the preheating stage is determined;

[0008] Determining the sedimentation influence of the lesion tissue based on the interference degree and the temperature change during the preheating stage;

[0009] Determine the ablation intervention degree at each sampling moment based on the temperature change and pressure change at each sampling moment relative to the previous sampling moment in the actual ablation stage, and the difference between the preset target temperature and the temperature value at each sampling moment;

[0010] Based on the sedimentation influence degree and the ablation intervention degree, and in combination with the initial power value of the actual ablation stage, the power value at the next sampling moment in the radiofrequency ablation process is obtained.

[0011] In one embodiment, the process of determining the interference degree is:

[0012] The difference between the temperature value at the end of preheating and the preset target temperature is recorded as the temperature difference;

[0013] Arrange all the temperature values ​​collected during the preheating phase in time sequence to form a temperature sequence;

[0014] Obtaining an inflection point in the temperature sequence, and taking the time when the inflection point appears as the time when the temperature change trend changes;

[0015] The interference degree is positively correlated with the temperature difference and the duration respectively.

[0016] In one embodiment, the expression of the interference degree is:

[0017] ;

[0018] In the formula, A represents the degree of interference of the temperature of the lesion tissue during the preheating stage; and Respectively represent the preset target temperature and the temperature value at the end of preheating; Indicates the duration from the start of preheating to the moment when the inflection point appears.

[0019] In one embodiment, the process of determining the settlement influence is as follows:

[0020] Performing straight-line fitting on all temperature values ​​before and after the inflection point in the temperature sequence respectively;

[0021] The difference between the slopes of the two fitted straight lines is recorded as the slope difference;

[0022] The sedimentation influence degree is positively correlated with the interference degree, and negatively correlated with the slope difference.

[0023] In one embodiment, the expression of the settlement influence degree is:

[0024] ;

[0025] In the formula, B represents the sedimentation influence of the lesion tissue; A represents the degree of interference of the temperature of the lesion tissue during the preheating stage; , They respectively represent the slopes of the straight lines fitted by all temperature values ​​before and after the inflection point in the temperature series.

[0026] In one embodiment, the process of determining the ablation intervention degree is:

[0027] The difference in temperature between each sampling moment and its adjacent sampling moment, and the difference in pressure between each sampling moment and its adjacent sampling moment are recorded as temperature difference and pressure difference, respectively;

[0028] Calculate the difference between the preset target temperature and the temperature value at each sampling time;

[0029] The ablation intervention degree is positively correlated with the temperature difference and the difference value, and negatively correlated with the pressure difference.

[0030] In one embodiment, the ablation intervention degree is expressed as:

[0031] ;

[0032] In the formula, represents the ablation intervention degree at the t-th sampling moment; , Respectively represent the temperature values ​​at the t-th and t-1-th sampling moments; , Respectively represent the pressure values ​​at the t-th and t-1-th sampling moments; ε represents a value preset to be greater than 0; exp( ) represents an exponential function with a natural constant as the base; Represents the difference between the preset target temperature and the temperature value at the tth sampling moment.

[0033] In one embodiment, the process of determining the power value at the next sampling moment is:

[0034] Obtaining a fusion result of the sedimentation influence degree and the ablation intervention degree;

[0035] The power value at the next sampling moment is positively correlated with the initial power value and the fusion result respectively.

[0036] In one embodiment, the expression of the power value at the next sampling moment is:

[0037] ;

[0038] In the formula, Indicates the first The power value at each sampling moment; Indicates the power value at the first sampling moment of the actual ablation phase during the radiofrequency ablation process; is the preset power adjustment amount; represents the normalized function; B represents the sedimentation influence of the lesion tissue; represents the ablation intervention degree at the tth sampling moment.

[0039] In a second aspect, an embodiment of the present application further provides a solid tumor radiofrequency ablation system, comprising a radiofrequency generating unit, a radiofrequency ablation electrode, a negative electrode plate, a radiofrequency control unit and a computer, wherein the radiofrequency control unit is used to collect power values ​​in real time during the radiofrequency ablation of solid tumors;

[0040] Based on the difference between the temperature at the end of preheating and the preset target temperature during the radiofrequency ablation process, and the time required from the start of preheating to the moment when the temperature change trend changes, the degree of interference with the temperature of the lesion tissue during the preheating stage is determined;

[0041] Determining the sedimentation influence of the lesion tissue based on the interference degree and the temperature change during the preheating stage;

[0042] Determine the ablation intervention degree at each sampling moment based on the temperature change and pressure change at each sampling moment relative to the previous sampling moment in the actual ablation stage, and the difference between the preset target temperature and the temperature value at each sampling moment;

[0043] Based on the sedimentation influence degree and the ablation intervention degree, and in combination with the initial power value of the actual ablation stage, a power value at the next sampling moment in the radiofrequency ablation process is obtained;

[0044] The radiofrequency ablation electrode is used to collect temperature and pressure values ​​in real time during radiofrequency ablation of solid tumors.

[0045] This application has at least the following beneficial effects:

[0046] This application obtains the sedimentation influence of the lesion tissue by analyzing the temperature rise during the preheating stage during the radiofrequency ablation process, as well as the difference between the temperature value after the preheating and the preset target temperature, reflecting the degree to which the temperature of the lesion tissue is affected by the blood heat sedimentation effect of the lesion tissue itself and the surrounding normal tissue, so as to facilitate the determination of the intensity of the regulation of the radiofrequency parameters in the later stage;

[0047] Furthermore, by analyzing the changes in temperature and pressure values ​​within the ablation range of the radiofrequency ablation electrode needle, as well as the difference between the preset target temperature and the actual temperature value, the ablation intervention degree is obtained to measure the suitability of the power value at each sampling moment for radiofrequency ablation; then, based on the sedimentation influence degree and the ablation intervention degree, the power value at the next sampling moment is obtained, fully considering the heat sedimentation effect during radiofrequency ablation, as well as the difference between the preset target temperature and the actual temperature value. When the heat sedimentation effect is greater and the actual temperature value is lower than the preset target temperature, the power value is greatly increased. When the heat sedimentation effect is smaller and the actual temperature is higher than the preset target temperature, the power value is adjusted very slightly. The power value is dynamically regulated in combination with the actual situation during the ablation process, thereby improving the treatment effect on solid tumors. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 A flowchart of a method for controlling radio frequency parameters of a radio frequency ablation system for solid tumors provided in one embodiment of the present application;

[0050] Figure 2 It is a schematic diagram of the structure of a radiofrequency ablation electrode needle;

[0051] Figure 3 A schematic diagram of the process of determining the interference degree;

[0052] Figure 4 The figure is a flow chart for determining the influence of settlement;

[0053] Figure 5 Schematic diagram of the process for determining the degree of ablation intervention. DETAILED DESCRIPTION

[0054] In the description of the embodiments of the present application, words such as "exemplary", "or", "for example" and the like are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "or", "for example" and the like is intended to present related concepts in a concrete manner.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the present application. The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It should be understood that, unless otherwise specified, " / " means or.

[0056] It should also be noted that the terms "first" and "second" in the present application are used to distinguish similar objects rather than to describe a specific order or sequence.

[0057] The following is a detailed description of a solid tumor radiofrequency ablation system and a radiofrequency parameter control method provided by the present application in conjunction with the accompanying drawings.

[0058] See also Figure 1 , which shows a flowchart of a method for controlling radio frequency parameters of a solid tumor radio frequency ablation system provided by an embodiment of the present application, the method comprising the following steps:

[0059] Step 1: Real-time acquisition of power, temperature and pressure values ​​during radiofrequency ablation of solid tumors.

[0060] The solid tumor radiofrequency ablation system mainly includes: a radiofrequency generating unit, a radiofrequency ablation electrode, a negative electrode plate and a radiofrequency control unit.

[0061] RF generating unit: generates RF current of specific power by receiving control signals from the RF control unit;

[0062] Radiofrequency ablation electrode: It is inserted into the lesion tissue of solid tumor under the guidance of medical imaging, and treats the lesion tissue based on radiofrequency current, serving as the positive electrode.

[0063] Negative electrode plate: Generally in direct contact with the skin, serving as a negative electrode, forming a current loop with the radiofrequency ablation electrode.

[0064] Radiofrequency control unit: Based on the feedback data from the radiofrequency ablation electrodes, dynamic adjustment of radiofrequency parameters during the radiofrequency ablation process is achieved.

[0065] In this embodiment, the radiofrequency ablation electrode is a radiofrequency ablation electrode needle. The structural schematic diagram of the radiofrequency ablation electrode needle is as shown in FIG. Figure 2 As shown, Figure 2 In the figure, 1 represents the handle of the radiofrequency ablation electrode needle, 2 represents the slide rail of the connecting rod, 3 represents the control button, 4 represents the sleeve, 5 represents the connecting rod of the electrode needle, 6 represents the thermocouple and the pressure sensor, and 7 represents the puncture structure.

[0066] This application uses animal tumor tissue as the research object. In order to more accurately obtain the treatment effect during radiofrequency ablation, parameter information needs to be collected in real time. The radiofrequency parameter information, i.e., the power value, is obtained through the radiofrequency control unit in the radiofrequency ablation system, and the temperature and pressure values ​​of the lesion tissue are obtained by using the thermocouple and pressure sensor on the radiofrequency ablation electrode needle.

[0067] In this embodiment, the sampling frequencies of the power value, temperature value and pressure value are all 30HZ. The value of the sampling frequency is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0068] All the collected power values, temperature values ​​and pressure values ​​are transmitted to the radio frequency control unit by wire. The radio frequency control unit dynamically adjusts the power value during the radio frequency ablation process by analyzing the changes in the power values, temperature values ​​and pressure values.

[0069] Step 2, based on the difference between the temperature at the end of preheating during the radiofrequency ablation process and the preset target temperature, and the time required from the start of preheating to the moment when the temperature change trend changes, determine the degree of interference with the temperature of the lesion tissue during the preheating stage.

[0070] During radiofrequency ablation treatment, the frequency output by the radiofrequency ablation electrode needle is between 350kHz and 500kHz, and the in situ inactivation of the lesion tissue is achieved through alternating current, and the heating temperature of RFA is between 60℃ and 100℃. In the traditional radiofrequency ablation treatment process, a radiofrequency current of a specific power is output within a specific time based on the size of the tumor, causing coagulative necrosis of tumor cells.

[0071] However, in the actual treatment process, due to the heat sinking effect of the lesion tissue, specifically, during the ablation process, the blood flow in the ablation area and the surrounding area will take away some heat, causing the temperature of the ablation area to drop, thus affecting the ablation effect. The blood flow corresponding to different lesions is different, so it is inaccurate to control the RF parameters based on the traditional mapping relationship between RF parameters and temperature. The RF parameters need to be controlled based on the conditions of the lesion tissue and the temperature.

[0072] When the radiofrequency ablation electrode needle penetrates the epidermal tissue of the animal, it punctures the inside of the lesion tissue in a direction under the guidance of medical imaging, and then turns on the radiofrequency generating unit to start heating the lesion tissue based on the traditional mapping relationship. Under the traditional mapping relationship, it is heated to the target temperature value. For example, under the traditional mapping relationship, it is heated for one minute at a power output of 40w, and it is determined that the target temperature of 60°C is reached, and radiofrequency ablation treatment of the lesion tissue cells is started. Among them, the value of the target temperature, as well as the heating time and power before reaching the target temperature need to be determined according to the specific lesion tissue. The time interval from the beginning of heating to reaching the target temperature is regarded as the preheating stage, and the time interval for continuing to heat the lesion tissue after reaching the target temperature is regarded as the actual ablation stage.

[0073] During the preheating phase, only data is collected without adjusting the RF parameters. When the target temperature is reached, data analysis and RF parameter adjustment begin. Specifically:

[0074] In the traditional preheating stage, the output power of the radiofrequency ablation electrode needle changes linearly with the increased temperature, so the target temperature value can be reached by heating for a fixed time at a specific power. However, due to the influence of blood circulation in the lesion tissue, the heating effect may be poor. Due to the influence of the heat deposition effect of the lesion tissue, during the initial preheating, the lesion tissue cells are not damaged, and the overall blood circulation effect is strong. At this time, the warming effect is poor. As the temperature rises, the cells at the puncture site of the radiofrequency ablation electrode needle are damaged, which hinders the blood circulation. Therefore, the temperature rises faster, resulting in an inflection point in the preheating stage. At the same time, at the end of the final preheating, the traditional mapping relationship believes that the target temperature has been reached, but the actual temperature at this time is still lower than the target temperature.

[0075] Based on the above analysis, all the temperature values ​​collected in the preheating stage are arranged in time sequence to form a temperature sequence. The Kneed algorithm is used to obtain the inflection point in the temperature sequence. Based on the difference between the temperature at the end of preheating during the radiofrequency ablation process and the preset target temperature, as well as the time required from the start of preheating to the appearance of the inflection point, the degree of interference with the temperature of the lesion tissue during the preheating stage is determined. The expression is:

[0076] ;

[0077] In the formula, A represents the degree of interference of the temperature of the lesion tissue during the preheating stage; and Respectively represent the preset target temperature and the temperature value at the end of preheating; It indicates the duration from the start of preheating to the moment when the inflection point appears. The value of the preset target temperature needs to be determined according to the specific lesion tissue.

[0078] It should be noted that the more blood vessels there are around the lesion tissue, the greater the impact of the heat sinking effect during the radiofrequency ablation process. Therefore, after the preheating is completed, the difference between the target temperature and the actual temperature value is the temperature difference. The larger the value, and because there are more blood vessels, the more heat can be taken away by blood flow, so the inflection point appears later in the preheating process, the longer the time from the inflection point to the preheating starting point is, and the greater the interference value is. The flow chart of determining the interference degree is as follows: Figure 3 shown.

[0079] Step 3: Determine the sedimentation influence of the lesion tissue based on the interference degree and the temperature change during the preheating stage.

[0080] Since the lesion tissue is usually small and attached to intact tissue cells, during the preheating process, as the temperature rises, although it can destroy the cells of the lesion tissue at the electrode needle target and hinder blood circulation, the intact tissue cells to which the lesion tissue is attached have normal blood supply, so that part of the heat is carried away by the blood flow of the normal tissue cells.

[0081] If the influence of normal tissue cell blood circulation on the radio frequency of the lesion tissue is greater, the temperature rises more slowly after the lesion tissue cells are damaged, so that the temperature rises slower after the inflection point until the end of preheating; if the influence is smaller, the temperature rises faster after the lesion tissue is damaged.

[0082] Based on the above analysis, based on the interference degree and the temperature change in the preheating stage, the sedimentation influence of the lesion tissue is determined, and the expression is:

[0083] ;

[0084] In the formula, B represents the sedimentation influence of the lesion tissue; A represents the degree of interference of the temperature of the lesion tissue during the preheating stage; , They represent the slopes of the straight lines formed by fitting all the temperature values ​​before and after the inflection point in the temperature series. Generally speaking, the temperature rise after the inflection point must be faster than the temperature rise before the inflection point, so the denominator Must not be zero.

[0085] It should be noted that: if the slopes of the fitted straight lines of the temperature values ​​before and after the inflection point are closer during the heating process, it means that the blood flow takes away more heat, the heat deposition effect is more serious, and the degree of intervention in the adjustment of the radio frequency parameters is greater; conversely, if the slopes of the fitted straight lines of the temperature values ​​before and after the inflection point are less close, it means that when the lesion tissue is destroyed, it can effectively hinder blood circulation, so the interference of the heat deposition effect is lighter, and the intervention in the adjustment of the radio frequency parameters will be smaller. The flow chart of determining the deposition influence is as follows Figure 4 shown.

[0086] Step 4, determining the ablation intervention degree at each sampling moment based on the temperature change and pressure change at each sampling moment relative to the previous sampling moment during the actual ablation stage, and the difference between the preset target temperature and the temperature value at each sampling moment.

[0087] By analyzing the changes in temperature values ​​during the preheating phase, the degree of influence of the heat deposition effect in the lesion tissue is obtained, and the data information during the subsequent radio frequency treatment process is further analyzed to adjust the radio frequency parameters during the subsequent radio frequency treatment process.

[0088] As malignant proliferating cells, the cells of the lesion tissue have certain cell structural characteristics. When they are active, the cell texture is relatively soft. During the radiofrequency treatment process, the alternating current signal output by the radiofrequency ablation electrode needle forms a current loop in the lesion tissue, causing the ions in the cells of the lesion tissue to vibrate. As the friction generates heat, the cell tissue around the radiofrequency ablation electrode needle is destroyed, hindering the proliferation and metastasis of the lesion tissue cells.

[0089] As the lesion cells are gradually inactivated, the nuclei of the lesion tissue cells rupture, and the chromatin becomes granular or lumpy, causing the nuclear membrane structure to thicken and rupture, the cytoplasm to granulate, and the structure of the organelles to gradually disappear, resulting in the gradual hardening of the lesion tissue ablation area and the gradual increase in the value of the pressure sensor.

[0090] Ideally, the temperature of the lesion tissue can be maintained at the target temperature. As radiofrequency ablation proceeds, the texture of the lesion tissue gradually hardens, causing the value of the pressure sensor to increase linearly. However, if affected by the heat sink effect, the actual temperature value may differ greatly from the target temperature and there may be fluctuations in the value, which will lead to poor overall radiofrequency ablation treatment effect. Therefore, it is necessary to adjust the radiofrequency parameters during the radiofrequency ablation process.

[0091] Based on the above analysis, the ablation intervention degree at each sampling moment is determined based on the temperature change and pressure change at each sampling moment relative to the previous sampling moment in the actual ablation stage, and the difference between the preset target temperature and the temperature value at each sampling moment. The expression is:

[0092] ;

[0093] In the formula, represents the ablation intervention degree at the t-th sampling moment; , Respectively represent the temperature values ​​at the t-th and t-1-th sampling moments; , Respectively represent the pressure values ​​at the t-th and t-1-th sampling moments; ε represents a value preset to be greater than 0, in order to avoid the denominator being zero. The value of ε is preset manually and can be set by the implementer. In this embodiment, the value of ε is 0.1; exp() represents an exponential function with a natural constant as the base; It represents the difference between the preset target temperature and the temperature value at the t-th sampling moment. It should be noted that, for the initial moment of the actual ablation stage, the temperature value and the pressure value are the values ​​at the end of preheating.

[0094] It should be noted that: if the difference between the temperature values ​​at two adjacent sampling moments is larger, it means that the temperature value is more unstable, resulting in poor radiofrequency ablation effect, and the smaller the difference between the pressure values ​​at two adjacent sampling moments is, At the same time, if the difference between the target temperature and the temperature value at the t-th sampling moment is positive, and the larger the difference, the greater the sedimentation effect of the lesion tissue, and the target temperature is not reached during the radiofrequency ablation process, then The larger the value of is, if the difference between the target temperature and the temperature value at the t-th sampling time is negative, it means that the temperature value at the t-th sampling time has exceeded the target temperature. In order to avoid excessive ablation of the lesion tissue and carbonization of the tissue, The value of is exponential decay, and the value of ablation intervention degree is extremely small. The flow chart of determining ablation intervention degree is as follows: Figure 5 shown.

[0095] Step 5: Based on the sedimentation influence degree and the ablation intervention degree and in combination with the initial power value of the actual ablation stage, the power value at the next sampling moment in the radiofrequency ablation process is obtained.

[0096] Based on the above analysis of the data collected during the preheating stage and the actual ablation stage of the radiofrequency ablation process, the radiofrequency parameters during the radiofrequency ablation process are adjusted. When the heat deposition effect of the lesion tissue is greater, the difference between the target temperature and the actual temperature is greater, and the power value of the radiofrequency generator needs to be increased. Conversely, if the radiofrequency ablation effect is smaller and the actual temperature value exceeds the target temperature, in order to avoid tissue carbonization, the power value of the radiofrequency generator should also be smaller.

[0097] Based on the above analysis, based on the sedimentation influence and the ablation intervention, and combined with the initial power value of the actual ablation stage, the power value at the next sampling moment in the radiofrequency ablation process is obtained, and the expression is:

[0098] ;

[0099] In the formula, Indicates the first The power value at each sampling moment; It indicates the power value at the first sampling moment of the actual ablation stage during the radiofrequency ablation process. Since the power of the radiofrequency ablation electrode needle can be adjusted, different powers are intended to ablate lesions in different parts of the tissue, and the radiofrequency ablation time is different, so Please refer to the instrument manual for the specific value of; The preset power adjustment amount is used to control the power adjustment range; represents the normalized function; B represents the sedimentation influence of the lesion tissue; represents the ablation intervention degree at the t-th sampling moment; The power value at the next sampling moment is calculated based on the power value at the current moment, in order to limit the power within the normal range, avoid overshoot, and avoid calculating the power value at the next sampling moment based on the power value at the current moment, resulting in cumulative errors.

[0100] In this embodiment, in order to avoid excessive power adjustment, the preset power adjustment value is 5W. The preset power adjustment value is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0101] It should be noted that: if the thermal deposition effect of the lesion tissue is greater, the deposition influence and ablation intervention values ​​will be greater, so the power value at the next moment will be increased to improve the ablation effect of the lesion tissue; if the thermal deposition effect of the lesion tissue is smaller, or the actual temperature exceeds the target temperature, the power value at the next sampling moment will be adjusted to a smaller extent to avoid excessive ablation causing tissue carbonization.

[0102] In this embodiment, the Min-Max normalization method is used to Normalization is performed, as another implementation method, in which On the basis of the normalization processing, the implementer may adopt other existing technologies for normalization processing, such as hyperbolic tangent function, decimal calibration normalization method, etc., and this application does not impose any special restrictions.

[0103] Step 6: Output the adjusted RF parameter information through the RF generating unit.

[0104] The power value at the next sampling moment is transmitted to the RF generating unit, and the PID controller is used in the RF generating unit to calculate the power value at the current sampling moment. and the power value at the next sampling moment , to achieve power control of RF signals.

[0105] Based on the same inventive concept as the above method, an embodiment of the present application further provides a solid tumor radiofrequency ablation system, including a radiofrequency generating unit, a radiofrequency ablation electrode, a negative electrode plate, a radiofrequency control unit and a computer.

[0106] A radio frequency generating unit, used for generating a radio frequency current of a specific power by receiving a control signal from a radio frequency control unit;

[0107] The radiofrequency ablation electrode is used to penetrate into the lesion tissue of a solid tumor under the guidance of medical imaging, treat the lesion tissue based on radiofrequency current, and collect temperature and pressure values ​​in real time during the radiofrequency ablation of the solid tumor, as a positive electrode.

[0108] The negative electrode plate is used to directly contact the skin and serve as a negative electrode to form a current loop with the radiofrequency ablation electrode.

[0109] The radio frequency control unit is used to collect the power value in real time during the radio frequency ablation of solid tumors; based on the difference between the temperature at the end of preheating and the preset target temperature during the radio frequency ablation process, and the time required from the start of preheating to the moment when the temperature change trend changes, determine the degree of interference with the temperature of the lesion tissue during the preheating stage;

[0110] Determining the sedimentation influence of the lesion tissue based on the interference degree and the temperature change during the preheating stage;

[0111] Determine the ablation intervention degree at each sampling moment based on the temperature change and pressure change at each sampling moment relative to the previous sampling moment in the actual ablation stage, and the difference between the preset target temperature and the temperature value at each sampling moment;

[0112] Based on the sedimentation influence degree and the ablation intervention degree, and in combination with the initial power value of the actual ablation stage, the power value at the next sampling moment in the radiofrequency ablation process is obtained.

[0113] Computers are used to guide the precise placement of radiofrequency ablation electrodes during radiofrequency ablation in combination with medical images.

[0114] In summary, the present application obtains the sedimentation influence of the lesion tissue by analyzing the temperature rise in the preheating stage during the radiofrequency ablation process, as well as the difference between the temperature value after the preheating and the preset target temperature, reflecting the degree to which the temperature of the lesion tissue is affected by the blood heat sedimentation effect of the lesion tissue itself and the surrounding normal tissue, so as to facilitate the determination of the intensity of the regulation of the radiofrequency parameters in the later stage;

[0115] Furthermore, by analyzing the changes in temperature and pressure values ​​within the ablation range of the radiofrequency ablation electrode needle, as well as the difference between the preset target temperature and the actual temperature value, the ablation intervention degree is obtained to measure the suitability of the power value at each sampling moment for radiofrequency ablation; then, based on the sedimentation influence degree and the ablation intervention degree, the power value at the next sampling moment is obtained, fully considering the heat sedimentation effect during radiofrequency ablation, as well as the difference between the preset target temperature and the actual temperature value. When the heat sedimentation effect is greater and the actual temperature value is lower than the preset target temperature, the power value is greatly increased. When the heat sedimentation effect is smaller and the actual temperature is higher than the preset target temperature, the power value is adjusted very slightly. The power value is dynamically regulated in combination with the actual situation during the ablation process, thereby improving the treatment effect on solid tumors.

[0116] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

[0117] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, no matter from which point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive.

Claims

1. A method for controlling radio frequency parameters of a solid tumor radio frequency ablation system, characterized in that: The method comprises the following steps: Real-time acquisition of power, temperature and pressure values ​​during radiofrequency ablation of solid tumors; Based on the difference between the temperature at the end of preheating and the preset target temperature during radiofrequency ablation, the time when the temperature difference and the temperature change trend change occurs is determined, and the degree of interference of the temperature of the lesion tissue during the preheating stage is determined in combination with the time required from the start of preheating to the time when the temperature change trend changes; Based on the difference between the temperature change trend before and after the temperature change trend changes, the slope difference is determined, and the sedimentation influence of the lesion tissue is determined in combination with the interference degree; The difference in temperature value between each sampling moment and its adjacent sampling moment, and the difference in pressure value between each sampling moment and its adjacent sampling moment are recorded as temperature difference and pressure difference, respectively, and the ablation intervention degree at each sampling moment is determined by combining the difference between the preset target temperature and the temperature value at each sampling moment; Based on the sedimentation influence degree and the ablation intervention degree, and in combination with the initial power value of the actual ablation stage, the power value at the next sampling moment in the radiofrequency ablation process is obtained.

2. The method for controlling radio frequency parameters of a solid tumor radio frequency ablation system according to claim 1, characterized in that: The process of determining the interference degree is as follows: The difference between the temperature value at the end of preheating and the preset target temperature is recorded as the temperature difference; Arrange all the temperature values ​​collected during the preheating phase in time sequence to form a temperature sequence; Obtaining an inflection point in the temperature sequence, and taking the time when the inflection point appears as the time when the temperature change trend changes; The interference degree is positively correlated with the temperature difference and the duration respectively.

3. The method for controlling radio frequency parameters of a radio frequency ablation system for solid tumors according to claim 2, characterized in that: The expression of the interference degree is: ； In the formula, A represents the degree of interference of the temperature of the lesion tissue during the preheating stage; and Respectively represent the preset target temperature and the temperature value at the end of preheating; Indicates the duration from the start of preheating to the moment when the inflection point appears.

4. The method for controlling radio frequency parameters of a radio frequency ablation system for solid tumors according to claim 2, characterized in that: The process of determining the settlement influence is as follows: Performing straight-line fitting on all temperature values ​​before and after the inflection point in the temperature sequence respectively; The difference between the slopes of the two fitted straight lines is recorded as the slope difference; The sedimentation influence degree is positively correlated with the interference degree, and negatively correlated with the slope difference.

5. The method for controlling radio frequency parameters of a radio frequency ablation system for solid tumors according to claim 4, characterized in that: The expression of the settlement influence is: ； In the formula, B represents the sedimentation influence of the lesion tissue; A represents the degree of interference of the temperature of the lesion tissue during the preheating stage; , They respectively represent the slopes of the straight lines fitted by all temperature values ​​before and after the inflection point in the temperature series.

6. The method for controlling radio frequency parameters of a solid tumor radio frequency ablation system according to claim 1, characterized in that: The process of determining the ablation intervention degree is as follows: The difference in temperature between each sampling moment and its adjacent sampling moment, and the difference in pressure between each sampling moment and its adjacent sampling moment are recorded as temperature difference and pressure difference, respectively; Calculate the difference between the preset target temperature and the temperature value at each sampling time; The ablation intervention degree is positively correlated with the temperature difference and the difference value, and negatively correlated with the pressure difference.

7. The method for controlling radio frequency parameters of a radio frequency ablation system for solid tumors according to claim 6, characterized in that: The expression of the ablation intervention degree is: ； In the formula, represents the ablation intervention degree at the t-th sampling moment; , Respectively represent the temperature values ​​at the t-th and t-1-th sampling moments; , Respectively represent the pressure values ​​at the t-th and t-1-th sampling moments; ε represents a value preset to be greater than 0; exp( ) represents an exponential function with a natural constant as the base; Represents the difference between the preset target temperature and the temperature value at the tth sampling moment.

8. The method for controlling radio frequency parameters of a radio frequency ablation system for solid tumors according to claim 1, characterized in that: The process of determining the power value at the next sampling moment is: Obtaining a fusion result of the sedimentation influence degree and the ablation intervention degree; The power value at the next sampling moment is positively correlated with the initial power value and the fusion result respectively.

9. The method for controlling radio frequency parameters of a radio frequency ablation system for solid tumors according to claim 8, characterized in that: The expression of the power value at the next sampling moment is: ； In the formula, Indicates the first The power value at each sampling moment; Indicates the power value at the first sampling moment of the actual ablation phase during the radiofrequency ablation process; is the preset power adjustment amount; represents the normalized function; B represents the sedimentation influence of the lesion tissue; represents the ablation intervention degree at the tth sampling moment.

10. A radiofrequency ablation system for solid tumors, implementing a radiofrequency parameter control method for a radiofrequency ablation system for solid tumors as claimed in claim 1, comprising a radiofrequency generating unit, a radiofrequency ablation electrode, a negative electrode plate, a radiofrequency control unit and a computer, characterized in that: The radio frequency control unit is used to collect the power value during radio frequency ablation of solid tumors in real time; Based on the difference between the temperature at the end of preheating and the preset target temperature during radiofrequency ablation, the time when the temperature difference and the temperature change trend change occurs is determined, and the degree of interference of the temperature of the lesion tissue during the preheating stage is determined in combination with the time required from the start of preheating to the time when the temperature change trend changes; Based on the difference between the temperature change trend before and after the temperature change trend changes, the slope difference is determined, and the sedimentation influence of the lesion tissue is determined in combination with the interference degree; The difference in temperature value between each sampling moment and its adjacent sampling moment, and the difference in pressure value between each sampling moment and its adjacent sampling moment are recorded as temperature difference and pressure difference, respectively, and the ablation intervention degree at each sampling moment is determined by combining the difference between the preset target temperature and the temperature value at each sampling moment; Based on the sedimentation influence degree and the ablation intervention degree, and in combination with the initial power value of the actual ablation stage, a power value at the next sampling moment in the radiofrequency ablation process is obtained; The radiofrequency ablation electrode is used to collect temperature and pressure values ​​in real time during radiofrequency ablation of solid tumors.

Images