Thermal ablation system

Abstract

The utility model discloses a thermal ablation system which comprises a thermal ablation needle body, a handle and a main machine, the thermal ablation needle body and the handle are sequentially connected with the main machine, a thermocouple and a heat conduction cable are arranged in the thermal ablation needle body, and the thermocouple is connected with the heat conduction cable; the handle is arranged at the near end of the thermal ablation needle body and connected with the host through a signal bus, a thermistor is arranged in the handle, one end of the thermistor is connected with the thermocouple, and the other end of the thermistor is connected with the host; the host comprises a bridge measuring circuit and an analog signal processing circuit, the input end of the bridge measuring circuit is connected with one end of the thermistor, the output end of the bridge measuring circuit is connected with the input end of the analog signal processing circuit, and the output end of the analog signal processing circuit is connected with the other end of the thermistor. The reference end voltage of the thermocouple can be automatically compensated, and economical and accurate measurement of the temperature of the refrigerant or the far end of the thermal ablation needle is achieved.

Description

Technical Field

[0001] The utility model belongs to the field of medical devices, and in particular relates to a thermal ablation system. Background Art

[0002] Electromagnetic radiation can be used to heat and destroy tumor cells. Treatment can involve inserting an ablation probe into tissue where the cancerous tumor has been identified. Once the ablation probe is properly positioned, the ablation probe emits electromagnetic radiation into the tissue surrounding the ablation probe.

[0003] In the treatment of diseases such as cancer, it has been found that certain types of tumor cells denature at elevated temperatures slightly lower than those that normally damage healthy cells. Known treatment methods, such as hyperthermia, heat diseased cells to temperatures above 41°C while maintaining adjacent healthy cells below the temperature at which irreversible cell damage occurs. These methods involve applying electromagnetic radiation to heat or ablate tissue.

[0004] Because there is a small temperature difference between the temperature required to denature malignant cells and the temperature that usually causes damage to healthy cells, precise temperature control of known heating patterns is required to produce a more predictable temperature distribution so that minimal electrosurgical energy can be applied around the tissue to achieve the goal of eradicating tumor cells while avoiding damage to other healthy tissue.

[0005] At present, there are three main types of temperature measurement for thermal ablation applicators used in clinical microwave tumor ablation: ① Thermocouple temperature measurement. In thermal ablation applications, it requires adapters and long-distance thermocouple compensation lines. The long-distance thermocouple compensation lines lead to high costs and are not conducive to actual production. ② Refrigerant temperature measurement. The temperature of the thermal ablation applicator is reflected by the temperature of the refrigerant medium. In the application, the distance between the refrigerant medium and the working part of the needle rod of the ablation applicator is too far, and there is a large temperature difference during measurement. ③ Thermistor integrated type. This solution requires no temperature difference between the reference end and the compensation wire node. The space inside the handle and the energy transmission cable will generate temperature rise. There is a large temperature difference between the reference end and the thermistor, resulting in inaccurate temperature measurement.

[0006] Existing solution A requires the use of longer thermocouple compensation wires, which are more expensive than pure copper wires. In addition, the ablation needle drags a very long cable, which is inconvenient to produce and use. The thermistor is located inside the main chassis, and the reference end is located outside the main chassis. There is a certain distance in space, and there may be a large temperature difference. This solution of collecting the voltages of the thermistor and thermocouple separately and then performing software calculations may not respond well to faster temperature changes. In some applications, thermistors are integrated into the chip. In other applications, a special temperature measurement chip is used to directly compensate the measured temperature. However, in terms of the underlying logic, it is no different from setting up a thermistor separately, and the aforementioned disadvantages also exist.

[0007] The existing solution B can only obtain the temperature of the refrigerant in the refrigerant container, but cannot obtain the temperature inside the needle rod of the thermal ablation needle.

[0008] In the existing solution C, the signal line is a copper wire or a thermocouple compensation wire, and the signal connector is made of copper. Because when the ablation needle is working, the space inside the handle and the energy transmission cable will generate temperature rise, and there is a huge temperature difference between the reference end and the thermistor. The premise that this solution is theoretically feasible is that there is no temperature difference between the reference end and the compensation wire node. In fact, the reference end and the compensation wire node are located inside and outside the handle in space, and there may be a large temperature difference. If the copper wire in the connector here is changed to the same material as the thermocouple compensation wire, this solution is feasible, but it is more expensive.

[0009] In summary, the disadvantages of the prior art are as follows: the long cable dragged by the conventional ablation needle microwave makes it inconvenient to produce and use, resulting in inaccurate temperature measurement. Thermocouple compensation wires are usually used, which are relatively expensive. It is necessary to propose a new thermal ablation system. Utility Model Content

[0010] The technical purpose of the utility model is to provide a thermal ablation system, which adopts a thermal ablation solution of remote compensation thermocouple temperature measurement, and can automatically compensate the reference terminal voltage of the thermocouple through hardware circuit design to improve the temperature measurement accuracy.

[0011] To solve the above problems, the technical solution of the utility model is:

[0012] The utility model provides a thermal ablation system, comprising: a thermal ablation needle, a handle and a host, wherein the thermal ablation needle and the handle are connected to the host in sequence.

[0013] A thermocouple and a heat-conducting cable are provided in the thermal ablation needle body, the heat-conducting cable extends along the hot end of the thermocouple toward the cold end, the thermocouple is connected to the heat-conducting cable, and the temperature of the hot end of the thermocouple is transferred toward the cold end;

[0014] A handle is arranged at the proximal end of the thermal ablation needle body, the handle is connected to the host through a signal bus, a thermistor is arranged in the handle, one end of the thermistor is connected to the thermocouple, and the other end of the thermistor is connected to the host;

[0015] The host comprises a bridge measurement circuit and an analog signal processing circuit, wherein the input end of the bridge measurement circuit is connected to one end of the thermistor, the output end of the bridge measurement circuit is connected to the input end of the analog signal processing circuit, and the output end of the analog signal processing circuit is connected to the other end of the thermistor.

[0016] Preferably, a first signal connector is provided in the handle, a first port of the first signal connector is connected to one end of the thermocouple, a second port of the first signal connector is connected to one end of the thermistor, and a third port of the first signal connector is connected to the other end of the thermistor and to the other end of the thermocouple.

[0017] Preferably, a second signal connector is provided in the handle, a first port of the second signal connector is connected to one end of the thermocouple, a second port of the second signal connector is connected to the other end of the thermocouple, a third port of the second signal connector is connected to one end of the thermistor, and a fourth port of the second signal connector is connected to the other end of the thermistor.

[0018] Preferably, the thermally conductive cables connected to both ends of the thermocouple are made of constantan wire and copper wire respectively.

[0019] Preferably, a third signal connector is provided in the host, a first port of the third signal connector is connected to a measurement port corresponding to the analog signal processing circuit, a second port of the third signal connector is connected to a node B corresponding to the bridge measurement circuit, a corresponding node C of the bridge measurement circuit is connected to another measurement port corresponding to the analog signal processing circuit, and a third port of the third signal connector is connected to a node A corresponding to the bridge measurement circuit.

[0020] Preferably, the ports on the first signal connector are connected to the ports on the third signal connector in a one-to-one correspondence via a signal bus.

[0021] Preferably, one end of the thermistor RT is connected to the T2-PT signal terminal, and the other end of the thermistor RT is connected to the T1-PT signal terminal, wherein the T2-PT signal terminal refers to the thermistor node b at the target measurement position on the thermal conductive cable connected to one end of the thermistor, and the T1-PT signal terminal refers to the thermistor node c at the target measurement position on the thermal conductive cable connected to the other end of the thermistor.

[0022] Preferably, the bridge measurement circuit includes a first resistor R1, a second resistor R2, a third resistor R3 and a current-limiting resistor R7, a first capacitor C1, a second capacitor C6, a third capacitor C10 and a fourth capacitor C11, the first resistor R1, the second resistor R2 and the third resistor R3, the T1-CU port of the first signal connector and the T1-PT port of the first signal connector are connected in series in sequence, one end of the first resistor R1 is connected to one end of the third resistor R3 and connected to a power supply, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to the other end of the third resistor R3, and the other end of the second resistor R2 is connected to the current-limiting resistor R7 and grounded, the other end of the first resistor R1 is connected to the first capacitor C1, the second capacitor C6 and the third capacitor C10 connected in series and grounded, and the other end of the second resistor R2 is connected to the fourth capacitor C11 and grounded.

[0023] Preferably, the analog signal processing circuit includes an instrumentation amplifier, a plurality of resistors and a plurality of capacitors to form a differential mode decoupling and common mode coupling circuit, in which the T1-R signal and a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6 connected in series are connected to a first port of the instrumentation amplifier, the second port of the instrumentation amplifier and a seventh resistor R8 are connected to a third port of the instrumentation amplifier, the T1-CU signal and an eighth resistor R11, a ninth resistor R12 and a tenth resistor R13 connected in series are connected to a fourth port of the instrumentation amplifier, and one end of the fourth resistor R4 and the fifth resistor R5 are connected to one end of a fifth capacitor C3 and are grounded, the other end of the fifth capacitor C3 are connected to the sixth capacitor C7 and the seventh capacitor C12 and are grounded, the fifth resistor R5 and the first resistor R11 are connected to the first resistor R12 and the second resistor R13 are connected to the first resistor R11 and the first resistor R13 are connected to the second resistor R13, and the fourth resistor R4 and the fifth resistor R5 are connected to one end of a fifth capacitor C3 and are grounded, the fifth capacitor C3 and the sixth capacitor C7 and the seventh capacitor C12 are connected to the first ... One end of the connection point of the sixth resistor R6 is connected to one end of the eighth capacitor C4 and grounded, the other end of the eighth capacitor C4 is connected to the ninth capacitor C8 and the tenth capacitor C13 and grounded, one end of the connection point of the sixth resistor R6 and the first port of the instrument amplifier is connected to one end of the eleventh capacitor C5 and grounded, the other end of the eleventh capacitor C5 is connected to the twelfth capacitor C9 and the thirteenth capacitor C14 and grounded, and the first port of the instrument amplifier is connected to the eleventh resistor R15 and grounded, the fourth port of the instrument amplifier is connected to the twelfth resistor R14 and grounded, the fifth port of the instrument amplifier is grounded, the seventh port of the instrument amplifier and the thirteenth resistor R9 are connected to the output connector, and the eighth port of the instrument amplifier is connected to the fourteenth capacitor C2 and grounded, thereby achieving multi-stage reduction of transmission line interference to the system.

[0024] Preferably, the instrument amplifier adopts INA821.

[0025] Due to the adoption of the above technical solution, the utility model has the following advantages and positive effects compared with the prior art:

[0026] The utility model provides a thermal ablation system, which is suitable for a thermal ablation needle with remote compensation thermocouple temperature measurement;

[0027] 1. Miniaturization eliminates the long cable dragged by the conventional ablation needle microwave, making it easier to manufacture and use.

[0028] 2. Intelligence: In addition to connecting thermistors, the signal connector can also connect other functional devices in the handle.

[0029] 3. Cost saving: Instead of using thermocouple compensation wire, cheaper copper wire is used. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those skilled in the art. The accompanying drawings are only for the purpose of illustrating the preferred embodiment and are not to be considered as limiting the present invention.

[0031] Figure 1 This is a schematic diagram of a thermal ablation system in an embodiment of the utility model;

[0032] Figure 2 This is an example diagram of connecting thermistor cables in an embodiment of the utility model;

[0033] Figure 3 This is an example diagram of a bridge measurement circuit in an embodiment of the utility model;

[0034] Figure 4 The circuit diagram of the thermistor and the thermocouple in the embodiment of the utility model is shown as an example;

[0035] Figure 5 This is an example diagram of an analog signal processing circuit in an embodiment of the present utility model;

[0036] Figure 6 This is another example diagram of the connection of the thermal ablation system in the embodiment of the utility model. DETAILED DESCRIPTION

[0037] The following is an explanation of the implementation of the utility model by specific specific examples, and those skilled in the art can easily understand other advantages and effects of the utility model from the content disclosed in this specification. The utility model can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the utility model. It should be understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation of the utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0038] It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood by specific circumstances.

[0039] See also Figure 1 As shown, the utility model provides a thermal ablation system, comprising: a thermal ablation needle body, a handle and a main unit, the thermal ablation needle body and the handle are connected to the main unit in sequence, a thermocouple and a heat-conductive cable are provided in the thermal ablation needle body, the heat-conductive cable extends along the hot end of the thermocouple toward the cold end, the thermocouple is connected to the heat-conductive cable, and the temperature of the hot end of the thermocouple is transferred toward the cold end; a handle is arranged at the proximal end of the thermal ablation needle body, the handle is connected to the main unit through a signal bus, a thermistor is provided in the handle, one end of the thermistor is connected to the thermocouple, and the other end of the thermistor is connected to the main unit; the main unit comprises a bridge measurement circuit and an analog signal processing circuit, the input end of the bridge measurement circuit is connected to one end of the thermistor, the output end of the bridge measurement circuit is connected to the input end of the analog signal processing circuit, and the output end of the analog signal processing circuit is connected to the other end of the thermistor.

[0040] A first signal connector is provided in the handle, a first port of the first signal connector is connected to one end of the thermocouple, a second port of the first signal connector is connected to one end of the thermistor, and a third port of the first signal connector is connected to the other end of the thermistor and to the other end of the thermocouple. In implementation, the signal connector includes three ports a, b, and c, port a is connected to one end of the thermocouple, port b is connected to one end of the linear thermistor, and port c is connected to the other end of the linear thermistor to the other end of the thermocouple.

[0041] A second signal connector is provided in the handle, a first port of the second signal connector is connected to one end of the thermocouple, a second port of the second signal connector is connected to the other end of the thermocouple, a third port of the second signal connector is connected to one end of the thermistor, and a fourth port of the second signal connector is connected to the other end of the thermistor. In implementation, the signal connector includes four ports a, b, c, and d, port a is connected to one end of the thermocouple, port b is connected to the other end of the thermocouple, port c is connected to one end of the thermistor, and port d is connected to the other end of the linear thermistor.

[0042] Those skilled in the art will appreciate that in this embodiment, all resistors on the bridge measurement circuit can be linear thermistors, and all placed in the handle. Using one resistor in the solution is economical, and more thermistors mean that the measurement can be more accurate and sensitive.

[0043] One end of the thermistor RT is connected to the T2-PT signal end, and the other end of the thermistor RT is connected to the T1-PT signal end, wherein the T2-PT signal end refers to the thermistor node b at the target measurement position on the thermal conductive cable where one end of the thermistor is connected, and the T1-PT signal end refers to the thermistor node c at the target measurement position on the thermal conductive cable where the other end of the thermistor is connected. The first port of the signal connector T0 is connected to the T1-KT signal terminal, and the second port of the signal connector T0 is connected to the T1-CU terminal, wherein the T1-CU signal terminal refers to the copper node a at the target measurement position on the thermal conductive cable where one end of the thermocouple is connected, and T1-KT refers to the constantan node at the target measurement position on the thermal conductive cable where the other end of the thermocouple is connected, that is, the constantan node connecting the thermistor T-end to the thermal conductive cable where the signal connector is located; T+ refers to the end in contact with the thermocouple, that is, the copper wire, and T- refers to the other end in contact with the thermocouple, that is, the constantan wire. The T1-KT and T1-CU on the signal connector are the T+ and T- mentioned above, which are to be connected to the thermocouple, see Figure 1 shown.

[0044] See also Figure 2As shown, the thermally conductive cables connected at both ends of the thermocouple are made of constantan wire and copper wire respectively. Among them, the thermal conductivity of copper wire is higher than that of constantan wire. For example, the thermally conductive cable where T+ is located and the thermally conductive cable where T- is located are made of different materials, such as the thermally conductive cable where T+ is located is copper wire, and the thermally conductive cable where T- is located is constantan wire. Figure 2 The middle conductor shown in is the signal bus. The principle of thermocouple temperature measurement is to use the thermoelectric effect, that is, to connect two different metal conductors into a closed loop. If the temperatures of the two nodes are not equal, a thermoelectric potential will be generated in the measurement loop; the magnitude and direction of the thermoelectric potential are only related to the characteristics of the two materials and the temperature of the measuring end, and there is a fixed functional relationship between the thermoelectric potential and the measured temperature.

[0045] In one embodiment, Figure 1 As shown, a third signal connector is provided in the host, a first port of the third signal connector is connected to a measurement port corresponding to the analog signal processing circuit, a second port of the third signal connector is connected to a B node corresponding to the bridge measurement circuit, a corresponding C node of the bridge measurement circuit is connected to another measurement port corresponding to the analog signal processing circuit, and a third port of the third signal connector is connected to an A node corresponding to the bridge measurement circuit.

[0046] In this embodiment, in order to realize thermal ablation by remote compensation thermocouple temperature measurement, Figure 3 As shown, the bridge measurement circuit includes a first resistor R1, a second resistor R2, a third resistor R3 and a current limiting resistor R7, a first capacitor C1, a second capacitor C6, a third capacitor C10 and a fourth capacitor C11, the first resistor R1, the second resistor R2 and the third resistor R3, the T1-CU port of the first signal connector and the T1-PT port of the first signal connector are connected in series in sequence, one end of the first resistor R1 is connected to one end of the third resistor R3 and connected to a power supply, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to the other end of the third resistor R3, and the other end of the second resistor R2 is connected to the current limiting resistor R7 and grounded, the other end of the first resistor R1 is connected to the first capacitor C1, the second capacitor C6 and the third capacitor C10 connected in series and grounded, and the other end of the second resistor R2 is connected to the fourth capacitor C11 and grounded.

[0047] Those skilled in the art will appreciate that the thermocouple structure in this embodiment is composed of Figure 3 Bridge measurement part, Figure 4 Thermistor-Thermocouple Part and Figure 5 The analog signal processing part consists of three parts. The bridge measurement part is placed in the main unit, and the thermistor-thermocouple part is placed at the handle end. Figure 3Among them, R1, R2, R3, R7 and RT together constitute a bridge circuit, R1, R2, R3 are precision resistors, R7 is a current limiting resistor, and RT is a thermistor. Figure 1 The T1-CU and T1-KT are connected to the resistor RT in the handle through the signal connector, and the signal connector T0 is connected to the A end of the thermocouple material and the B end of the thermocouple material. The three capacitors C1, C10, and C11 and R1, R2, and R3 form an RC filter circuit, which is used to remove the differential mode interference caused by the transmission line antenna; C6 is used to couple the common mode interference caused by the transmission line antenna on both sides of the bridge. T1-KT , U T1-R The voltage is in the millivolt level, which is not easy to be read by MCU / ADC. And because the transmission line is too long, it is easy to get measurement data due to transmission line loss and antenna interference. Therefore, the analog signal processing part is used. Figure 3 Process the measured signal.

[0048] The analog signal processing circuit includes an instrumentation amplifier U1, a plurality of resistors and a plurality of capacitors to form a differential mode decoupling and common mode coupling circuit, in which a T1-R signal end and a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6 connected in series are connected to a first port of the instrumentation amplifier, a second port of the instrumentation amplifier and a seventh resistor R8 are connected to a third port of the instrumentation amplifier, a T1-CU signal end and an eighth resistor R11, a ninth resistor R12 and a tenth resistor R13 connected in series are connected to a fourth port of the instrumentation amplifier, and one end of the fourth resistor R4 and the fifth resistor R5 connected at a point where the fourth resistor R4 is connected to one end of a fifth capacitor C3 and grounded, the other end of the fifth capacitor C3 is connected to a sixth capacitor C7 and a seventh capacitor C12 and grounded, and the fifth resistor R5 is connected to the sixth capacitor C7 and the seventh capacitor C12 and grounded. One end of the connection of the resistor R6 is connected to one end of the eighth capacitor C4 and grounded, the other end of the eighth capacitor C4 is connected to the ninth capacitor C8 and the tenth capacitor C13 and grounded, one end of the connection of the sixth resistor R6 and the first port of the instrument amplifier is connected to one end of the eleventh capacitor C5 and grounded, the other end of the eleventh capacitor C5 is connected to the twelfth capacitor C9 and the thirteenth capacitor C14 and grounded, and the first port of the instrument amplifier is connected to the eleventh resistor R15 and grounded, the fourth port of the instrument amplifier is connected to the twelfth resistor R14 and grounded, the fifth port of the instrument amplifier is grounded, the seventh port of the instrument amplifier is connected to the thirteenth resistor R9 to the output connector, and the eighth port of the instrument amplifier is connected to the fourteenth capacitor C2 and grounded, so as to achieve multi-stage reduction of the interference of the transmission line to the system. Among them, the T1-R signal end is a node connected to R1 and R2. The model used by the instrument amplifier U1 is I NA821.

[0049] Those skilled in the art can understand that the first half of the analog signal processing circuit is a differential mode decoupling and common mode coupling circuit, which is mainly composed of R4, R5, R6, R11, R12, R13 and surrounding capacitors. Its main purpose is to reduce the interference of the transmission line to the system in multiple stages until the signal quality is more than 95% of the interference signal; U1 and U REF1 The signal acquisition circuit of the amplified adjustable range (0-VS IG-5V) is constructed. The required temperature measurement range can be obtained by simply changing the UREF1 reference value. The amplified bridge measurement result UT = U REF1 +K(U T1-KT -U T1-R ), K is the magnification.

[0050] The measurement process can be summarized as follows: the RT thermistor affects the balance of the bridge to compensate for the cold end measurement data of the thermocouple. The compensation process is as follows: When the temperature is 25°C, the two ends of the bridge reach balance, U T1-R and U T1-CU equal, the measurement result UT is the thermocouple measurement voltage; when the temperature is higher or lower than 25℃, the thermistor PT resistance changes, the bridge is an unbalanced bridge, U T1-CU and U T1-PT- The voltage at the point increases or decreases accordingly, U T1-PT- Changes affecting U T2-R The voltage changes accordingly, thereby compensating for the change caused by the change in the cold end temperature of the thermocouple, so that the measurement result UT is still the thermocouple measurement voltage.

[0051] In another embodiment, see Figure 6 As shown, a fourth signal connector is provided in the host, and the first port of the fourth signal connector is connected to the first measurement port of the analog signal processing circuit, and the second port of the fourth signal connector is connected to the second measurement port of the analog signal processing circuit, for correspondingly measuring the two ends of ab in the handle; the third port of the fourth signal connector is connected to the third measurement port of the analog signal processing circuit, and the fourth port of the fourth signal connector is connected to the fourth measurement port of the analog signal processing circuit, for correspondingly measuring the two ends of the thermistor cd. The measurement port in this embodiment corresponds to the analog signal processing circuit to place the thermistor in the handle, close to the reference end of the thermocouple. Then, the cold end temperature of the thermocouple is obtained by separately calculating the voltage of the thermistor. Compared with the above scheme, the spatial distance between the thermistor and the reference end is very small, so it can be considered that the temperatures of the two are relatively close, and the voltages of the thermocouple and thermistor need to be collected separately.

[0052] In this embodiment, the port on the first signal connector is connected to the port on the third signal connector in a one-to-one correspondence through a signal bus, or the port on the second signal connector is connected to the port on the fourth signal connector in a one-to-one correspondence through a signal bus.

[0053] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A thermal ablation system, characterized in that: The invention comprises: a thermal ablation needle, a handle and a main unit, wherein the thermal ablation needle and the handle are connected to the main unit in sequence. A thermocouple and a heat-conducting cable are provided in the thermal ablation needle body, the heat-conducting cable extends along the hot end of the thermocouple toward the cold end, the thermocouple is connected to the heat-conducting cable, and the temperature of the hot end of the thermocouple is transferred toward the cold end; A handle is arranged at the proximal end of the thermal ablation needle body, the handle is connected to the host through a signal bus, a thermistor is arranged in the handle, one end of the thermistor is connected to the thermocouple, and the other end of the thermistor is connected to the host; The host comprises a bridge measurement circuit and an analog signal processing circuit, wherein the input end of the bridge measurement circuit is connected to one end of the thermistor, the output end of the bridge measurement circuit is connected to the input end of the analog signal processing circuit, and the output end of the analog signal processing circuit is connected to the other end of the thermistor.

2. The thermal ablation system according to claim 1, characterized in that: A first signal connector is provided in the handle, a first port of the first signal connector is connected to one end of the thermocouple, a second port of the first signal connector is connected to one end of the thermistor, and a third port of the first signal connector is connected to the other end of the thermistor and to the other end of the thermocouple.

3. The thermal ablation system according to claim 1, characterized in that: A second signal connector is provided in the handle, a first port of the second signal connector is connected to one end of the thermocouple, a second port of the second signal connector is connected to the other end of the thermocouple, a third port of the second signal connector is connected to one end of the thermistor, and a fourth port of the second signal connector is connected to the other end of the thermistor.

4. The thermal ablation system according to claim 1, characterized in that: The heat-conducting cables connected to the two ends of the thermocouple are respectively made of constantan wire and copper wire.

5. The thermal ablation system according to claim 1, characterized in that: A third signal connector is provided in the host, a first port of the third signal connector is connected to a measurement port corresponding to the analog signal processing circuit, a second port of the third signal connector is connected to a B node corresponding to the bridge measurement circuit, a corresponding C node of the bridge measurement circuit is connected to another measurement port corresponding to the analog signal processing circuit, and a third port of the third signal connector is connected to an A node corresponding to the bridge measurement circuit.

6. The thermal ablation system according to claim 2, characterized in that: The ports on the first signal connector are connected to the ports on the third signal connector in a one-to-one correspondence via a signal bus.

7. The thermal ablation system according to claim 1, characterized in that: One end of the thermistor RT is connected to the T2-PT signal end, and the other end of the thermistor RT is connected to the T1-PT signal end, wherein the T2-PT signal end refers to the thermistor node b at the target measurement position on the thermal conductive cable where one end of the thermistor is connected, and the T1-PT signal end refers to the thermistor node c at the target measurement position on the thermal conductive cable where the other end of the thermistor is connected.

8. The thermal ablation system according to claim 1, characterized in that: The bridge measurement circuit includes a first resistor R1, a second resistor R2, a third resistor R3 and a current-limiting resistor R7, a first capacitor C1, a second capacitor C6, a third capacitor C10 and a fourth capacitor C11. The first resistor R1, the second resistor R2 and the third resistor R3, the T1-CU port of the first signal connector and the T1-PT port of the first signal connector are connected in series in sequence. One end of the first resistor R1 is connected to one end of the third resistor R3 and connected to a power supply. The other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to the other end of the third resistor R3, and the other end of the second resistor R2 is connected to the current-limiting resistor R7 and grounded. The other end of the first resistor R1 is connected to the first capacitor C1, the second capacitor C6 and the third capacitor C10 connected in series and grounded, and the other end of the second resistor R2 is connected to the fourth capacitor C11 and grounded.

9. The thermal ablation system according to claim 1, characterized in that: The analog signal processing circuit includes an instrumentation amplifier, a plurality of resistors and a plurality of capacitors to form a differential mode decoupling and common mode coupling circuit, in which a T1-R signal and a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6 connected in series are connected to a first port of the instrumentation amplifier, a second port of the instrumentation amplifier and a seventh resistor R8 are connected to a third port of the instrumentation amplifier, a T1-CU signal and an eighth resistor R11, a ninth resistor R12 and a tenth resistor R13 connected in series are connected to a fourth port of the instrumentation amplifier, and one end of the fourth resistor R4 and the fifth resistor R5 connected at a point where the fourth resistor R4 and the fifth resistor R5 are connected to one end of a fifth capacitor C3 and grounded, the other end of the fifth capacitor C3 and the sixth capacitor C7 and the seventh capacitor C12 are connected to ground, and the fifth resistor R5 and the sixth resistor R6 are connected at a point where the fourth resistor R4 and the fifth resistor R5 are connected at a point where the fifth capacitor C3 and the sixth capacitor C7 and the seventh capacitor C12 are connected to ground, and the fifth resistor R5 and the sixth resistor R6 are connected at a point where the fifth capacitor C3 and the sixth capacitor C7 and the seventh capacitor C12 are connected to ground. One end of the connection point of R6 is connected to one end of the eighth capacitor C4 and grounded, the other end of the eighth capacitor C4 is connected to the ninth capacitor C8 and the tenth capacitor C13 and grounded, one end of the connection point of the sixth resistor R6 and the first port of the instrument amplifier is connected to one end of the eleventh capacitor C5 and grounded, the other end of the eleventh capacitor C5 is connected to the twelfth capacitor C9 and the thirteenth capacitor C14 and grounded, and the first port of the instrument amplifier is connected to the eleventh resistor R15 and grounded, the fourth port of the instrument amplifier is connected to the twelfth resistor R14 and grounded, the fifth port of the instrument amplifier is grounded, the seventh port of the instrument amplifier and the thirteenth resistor R9 are connected to the output connector, and the eighth port of the instrument amplifier is connected to the fourteenth capacitor C2 and grounded, thereby achieving multi-stage reduction of transmission line interference to the system.

10. The thermal ablation system according to claim 9, characterized in that: The instrument amplifier used is INA821.

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