Radio frequency signal generating device and radio frequency ablation instrument

Abstract

The embodiment of the invention relates to the field of radio frequency ablation, and discloses a radio frequency signal generation device and a radio frequency ablatometer, and the device comprises a radio frequency signal generation unit which is used for generating a PWM signal; the direct-current voltage output unit is used for acquiring an analog voltage generated based on the impedance change of the target ablation tissue, and outputting a first direct-current voltage matched with the impedance change based on the analog voltage; the primary side of the transformer is connected with the radio-frequency signal generating unit and the direct-current voltage output unit, and the transformer is used for converting the first direct-current voltage into peak voltage required by target radio-frequency power; and the radio-frequency signal output unit is connected with the secondary side of the transformer, and the radio-frequency signal output unit is used for superposing the peak voltage to the PWM signal, generating a radio-frequency signal of the target radio-frequency power and outputting the radio-frequency signal. The problem that the radiofrequency ablation treatment effect is poor due to the fact that the output power of the radiofrequency signals is fixed is solved, the output power of the radiofrequency signals is adjusted in time according to impedance changes, and the risks of biological tissue carbonization, burn and the like are prevented.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of radio frequency ablation, and in particular to a radio frequency signal generating device and a radio frequency ablation apparatus. Background Art

[0002] Radiofrequency ablation (RFA) is a local minimally invasive treatment. Compared with traditional surgical treatment, radiofrequency ablation has the advantages of precision, safety, fewer complications, faster patient recovery, less pain, and reliable results. It has been widely recognized by the international medical community and has become an important treatment for a variety of solid tumors (such as liver cancer, lung cancer, thyroid nodules, etc.) and arrhythmias.

[0003] Despite the significant advantages of RFA technology, the performance bottleneck of traditional equipment still restricts further improvement of clinical effects. Generally, the rated power of traditional radiofrequency ablation equipment is fixed and low. The treatment efficiency of radiofrequency ablation of biological tissues based on this fixed low rated power is limited. For example, for tumors with a diameter greater than 3 cm or lesions with rich blood supply, fixed low power may lead to prolonged ablation time and aggravated heat sinking effect (heat dissipation from surrounding tissues reduces ablation effect), increasing the risk of tumor residue or recurrence. In the treatment of tumors in organs with rich blood supply such as the liver and kidneys, traditional equipment may require multiple punctures or combined with other treatment methods due to insufficient energy, affecting the economic efficiency of the operation and patient experience. Summary of the invention

[0004] The purpose of the present invention is to at least provide a radio frequency signal generating device and a radio frequency ablation device, which can at least solve the problem of poor radio frequency ablation treatment effect caused by fixed radio frequency signal output power, and at least achieve the effect of timely adjusting the output power of the radio frequency signal according to impedance changes to prevent the risks of carbonization and burns of biological tissues.

[0005] To solve the above technical problems, at least one embodiment of the present invention provides a radio frequency signal generating device, comprising: A radio frequency signal generating unit, used for generating a PWM signal; A DC voltage output unit, configured to obtain an analog voltage generated based on an impedance change of a target ablation tissue, and output a first DC voltage matching the impedance change based on the analog voltage; A transformer, the primary side of which is connected to the RF signal generating unit and the DC voltage output unit, and the transformer is used to convert the first DC voltage into a peak voltage required by the target RF power; A radio frequency signal output unit is connected to the secondary side of the transformer, and is used to superimpose the peak voltage on the PWM signal to generate a radio frequency signal of a target radio frequency power and output the radio frequency signal.

[0006] At least one embodiment of the present invention further provides a radiofrequency ablation apparatus, comprising the above-mentioned radiofrequency signal generating device.

[0007] The radio frequency signal generating device and radio frequency ablation instrument of the present invention generate a PWM signal by a radio frequency signal generating unit, and a DC voltage output unit obtains an analog voltage generated based on the impedance change of the target ablation tissue, and outputs a first DC voltage matching the impedance change based on the analog voltage; the first DC voltage is converted into a peak voltage required for the target radio frequency power by a transformer, and then the peak voltage is superimposed on the PWM signal by the radio frequency signal output unit to output a radio frequency signal of the target radio frequency power. The present invention can timely adjust the first DC voltage output by the DC voltage output unit according to the impedance change of the target ablation tissue in the radio frequency ablation surgery, and then adjust the output power of the radio frequency signal to a higher target radio frequency power, thereby preventing the risks of carbonization and burns of biological tissues, and effectively improving the radio frequency ablation treatment effect.

[0008] In some optional embodiments, the radio frequency signal generating unit includes: A radio frequency control module, used to generate an original PWM square wave signal; A PWM circuit is connected to the RF control module, and the PWM circuit is used to convert the original PWM square wave signal The output is then electrically isolated and amplified.

[0009] The present invention generates an original PWM square wave signal through a radio frequency control module, and obtains the PWM square wave signal required by a radio frequency ablation instrument by electrically isolating and amplifying the PWM square wave signal, thereby preventing interference between signals.

[0010] In some optional embodiments, the PWM circuit includes: An anti-interference isolation chip, used for electrically isolating and amplifying the original PWM square wave signal; A push-pull circuit is connected to the anti-interference isolation chip, wherein the push-pull circuit includes two switch tubes that work alternately under the drive of the anti-interference isolation chip, and the push-pull circuit is used to output a PWM square wave through the alternate work of the two switch tubes.

[0011] The present invention implements electrical isolation and amplification processing of PWM square wave signals through an anti-interference isolation chip, and generates a driving signal for outputting the PWM square wave signal, thereby preventing interference between signals and realizing the transmission of the PWM square wave signal by driving two switching tubes to work alternately.

[0012] In some optional embodiments, the DC voltage output unit includes: an amplifying circuit, used for acquiring and amplifying an analog voltage generated based on impedance changes of a target ablation tissue; A follower circuit, connected to the amplifying circuit, and configured to output a second DC voltage according to the analog voltage; a power management circuit connected to the follower circuit, and configured to adjust a first DC voltage output by the power management circuit according to the second DC voltage, so that the first DC voltage matches the impedance change and the second DC voltage reaches a reference value; A feedback circuit is connected to the amplifying circuit and the power management circuit and is used for feeding back the regulated first DC voltage.

[0013] The present invention generates a second DC voltage that follows the analog voltage changes output by the amplifier circuit through a follower circuit. The power management circuit uses the second DC voltage to adjust and obtain a first DC voltage that matches the impedance. The first DC voltage is fed back to the amplifier circuit to prevent overvoltage or undervoltage. The first DC voltage is also output to a subsequent transformer and converted into a peak voltage required for the target RF power, so as to superimpose a RF signal of the target RF power on the basis of the PWM signal, thereby achieving a smooth change of the RF power signal.

[0014] In some optional embodiments, the transformer is used to convert a first DC voltage matching the impedance into a peak voltage required for a target RF power by adjusting a turns ratio.

[0015] The transformer in the present invention can convert the first DC voltage that matches the impedance into the peak voltage required for the higher target radio frequency power by adjusting the turns ratio, thereby realizing the output of the radio frequency signal. Therefore, on the basis of the transformer amplifying the first DC voltage, the target radio frequency power value is improved compared with the traditional radio frequency ablation device, meeting the high power requirements of the radio frequency ablation surgery, thereby improving the radio frequency ablation treatment effect.

[0016] In some optional embodiments, the DC voltage output unit also includes: a protection circuit, connected to the power management circuit and the transformer, for detecting line power and cutting off the output of the first DC voltage matching the impedance change when the line power exceeds a set power.

[0017] The present invention controls the output of the first DC voltage by detecting the line power, thereby controlling the normal output and cutoff of the radio frequency signal, thereby achieving the effect of protecting the components in the line.

[0018] In some optional embodiments, the protection circuit includes: A detection circuit connected to the power management circuit; A switch circuit connected to the detection circuit; The detection circuit is used for: detecting line power based on a first DC voltage matching the impedance change; When the line power exceeds the set power, the switch circuit is driven to cut off the output of the first DC voltage matching the impedance change; and when the line power does not exceed the set power, the switch circuit is driven to output the first DC voltage matching the impedance change.

[0019] The present invention realizes line power detection through a detection circuit, and then realizes output and cutoff of a first DC voltage through a driving switch circuit, thereby realizing a rapid cutoff response to power anomalies and avoiding component damage caused by excessive line power.

[0020] In some optional embodiments, the radio frequency signal output unit includes: A frequency selection circuit, connected to the secondary side of the transformer, for converting the PWM square wave signal output by the radio frequency signal generating unit into a sine wave signal; The radio frequency signal output module is connected to the frequency selection circuit and is used to superimpose the peak voltage on the sine wave signal to generate a radio frequency signal of a target radio frequency power and output the radio frequency signal.

[0021] The present invention converts the PWM square wave signal into a sinusoidal wave signal that is relatively safe for biological tissue through a frequency selection circuit, and further superimposes the peak voltage on the sinusoidal wave signal to generate a radio frequency signal of the target radio frequency power, thereby achieving accurate output of the radio frequency signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by the pictures in the corresponding drawings, and these exemplary descriptions do not constitute limitations on the embodiments.

[0023] Figure 1 is a structural schematic diagram of a radio frequency signal generating device provided by an embodiment of the present invention; Figure 2 is a structural schematic diagram of another radio frequency signal generating device provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the circuit principle of a radio frequency signal generating unit, a transformer and a radio frequency signal output unit provided by an embodiment of the present invention; Figure 4 It is a schematic diagram of the principle of a DC voltage output unit circuit provided by an embodiment of the present invention; Figure 5 It is a schematic diagram of the protection circuit principle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, it can be understood by those skilled in the art that in the embodiments of the present invention, many technical details are proposed in order to enable the reader to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present invention can also be implemented. The division of the following embodiments is for the convenience of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined and referenced with each other under the premise of no contradiction.

[0025] In order to facilitate understanding of the embodiments of the present invention, relevant contents about radiofrequency ablation are first introduced here.

[0026] Radio frequency ablation (RFA) is a local minimally invasive treatment. Compared with traditional surgical treatment, RFA has the advantages of precision, safety, fewer complications, faster patient recovery, less pain, and reliable results. It has been widely recognized by the international medical community and has been widely carried out at home and abroad. Generally, the rated power of traditional RFA equipment is fixed and the output power is low. The treatment effect of RFA on biological tissue based on this fixed low rated power needs to be improved.

[0027] In order to solve the above-mentioned technical problem of improving the effect of radiofrequency ablation treatment, the present invention proposes a radio frequency signal generating device. The implementation details of the radio frequency signal generating device of this embodiment are specifically described below. The following content is only the implementation details provided for the convenience of understanding and is not necessary for implementing this solution.

[0028] Embodiment 1: The structure of a radio frequency signal generating device of this embodiment can be as follows: Figure 1 As shown, it includes: a radio frequency signal generating unit 101, a DC voltage output unit 102, a transformer 103 and a radio frequency signal output unit 104.

[0029] The radio frequency signal generating unit 101 is used to generate a PWM signal.

[0030] Specifically, the RF signal generating unit 101 generates two sets of complementary PWM square waves.

[0031] The DC voltage output unit 102 is used to obtain an analog voltage generated based on the impedance change of the target ablation tissue, and output a first DC voltage matching the impedance change based on the analog voltage.

[0032] Specifically, the RF power adjustment instruction (control signal) generated based on the impedance change of the target ablation tissue can be converted into an analog voltage by the digital-to-analog conversion element, and the input DC voltage output unit 102 outputs a first DC voltage that matches the impedance change based on the weak analog voltage, thereby realizing RF power adjustment.

[0033] The transformer 103 has a primary side connected to the RF signal generating unit and the DC voltage output unit, and is used to convert the first DC voltage into a peak voltage required by the target RF power.

[0034] Specifically, the first DC voltage can be amplified by the transformer and converted into a peak voltage higher than the rated power required by a conventional radiofrequency ablation device, thereby increasing the radiofrequency power and improving ablation efficiency and treatment effect.

[0035] The RF signal output unit 104 is connected to the secondary side of the transformer, and is used to superimpose the peak voltage on the PWM signal, generate a RF signal with a target RF power, and output the RF signal.

[0036] In a specific implementation, the above-mentioned unit of the RF signal generating device can be integrated on an RF source board, and the RF power output can be further adjusted by adjusting the DC voltage output. Such an adjustment method has the characteristics of a small number of components, fast response, accurate precision, and smooth changes in output power.

[0037] In this embodiment, the RF signal generating unit generates a PWM signal, the DC voltage output unit obtains an analog voltage generated based on the impedance change of the target ablation tissue, and outputs a first DC voltage matching the impedance change based on the analog voltage; the first DC voltage is converted into a peak voltage required for the target RF power by a transformer, and then the RF signal output unit superimposes the peak voltage on the PWM signal to output a RF signal of the target RF power. The present invention can timely adjust the first DC voltage output by the DC voltage output unit according to the impedance change of the target ablation tissue in the RF ablation surgery, and then adjust the output power of the RF signal to a higher target RF power, thereby preventing the risks of carbonization and burns of biological tissues, and effectively improving the RF ablation treatment effect.

[0038] In some embodiments, Figure 2 As shown, the RF signal generating unit 101 includes a RF control module 1011 and a PWM circuit 1012. The RF control module 1011 is used to generate an original PWM square wave signal; the PWM circuit 1012 is connected to the RF control module 1011, and the PWM circuit 1012 is used to electrically isolate and amplify the original PWM square wave signal before outputting it.

[0039] Specifically, the radio frequency control module 1011 may be a MCU (Microcontroller Unit), which electrically isolates and amplifies the original PWM square wave signal through the PWM circuit 1012 to obtain the PWM square wave signal required by the radio frequency ablation device to prevent interference between signals.

[0040] In some embodiments, Figure 3 As shown, the PWM circuit 1012 includes: The anti-interference isolation chip 1012a is used to electrically isolate and amplify the original PWM square wave signal; The push-pull circuit 1012b is connected to the anti-interference isolation chip 1012a. The push-pull circuit 1012b includes two switch tubes Q8 and Q9 that work alternately under the drive of the anti-interference isolation chip 1012b. The push-pull circuit 1012b is used to output PWM square waves through the alternating operation of the two switch tubes Q8 and Q9.

[0041] In a specific implementation, two sets of PWM rectangular square waves can be generated by the RF control module 1011 (MCU) on the RF source board. After passing through the anti-interference isolation chip 1012a, the switch tubes Q8 and Q9 are driven to work alternately to obtain the PWM square wave required by the RF ablation device and transmit it to the transformer 103.

[0042] In this embodiment, the anti-interference isolation chip 1012a is used to electrically isolate and amplify the PWM square wave signal, and generate a driving signal for the PWM square wave signal output, which not only prevents interference between signals, but also realizes the transmission of the PWM square wave signal by driving the two switching tubes to work alternately.

[0043] In some embodiments, Figure 4 As shown, the DC voltage output unit 102 includes: Amplifying circuit 1021, used to obtain and amplify the analog voltage generated based on the impedance change of the target ablation tissue; A follower circuit 1022, connected to the amplifier circuit 1021, configured to output a second DC voltage according to the analog voltage; The power management circuit 1023 is connected to the follower circuit and is used to adjust the first DC voltage output by the power management circuit according to the second DC voltage so that the first DC voltage matches the impedance change and the second DC voltage reaches a reference value; The feedback circuit 1024 is connected to the amplifier circuit and the power management circuit, and is used to feed back the regulated first DC voltage.

[0044] In this embodiment, a second DC voltage that follows the analog voltage change output by the amplifier circuit is generated by a follower circuit. The power management circuit uses the second DC voltage to adjust and obtain a first DC voltage that matches the impedance. The first DC voltage is fed back to the amplifier circuit to prevent overvoltage or undervoltage. The first DC voltage is also output to a subsequent transformer and converted into a peak voltage required for the target RF power, so as to superimpose the PWM signal to form a RF signal of the target RF power, thereby achieving a smooth change of the RF power signal.

[0045] In a specific implementation, during the RF ablation procedure, the host computer obtains the impedance change of the target ablation tissue in real time. The impedance change causes the host computer to generate a RF power adjustment instruction (control signal). This weak control signal is converted into an analog voltage Ui by a digital-to-analog conversion element (for example, a digital-to-analog conversion chip), and then sent to the amplifier circuit 1021 for amplification to obtain U'. U' generates a second DC voltage Uo through a follower circuit 1022. Uo is a DC voltage that is adjustable following the analog voltage Ui (U'). The input voltage of the power management circuit 1023 is preset to a reference value. During the RF ablation procedure, the input voltage of the power management circuit 1023 (the second DC voltage Uo) changes following the analog voltage Ui caused by the impedance change. In order to match the first DC voltage VCC with the impedance change and the second DC voltage Uo reaches the reference value, the power management circuit 1023 adjusts the first DC voltage VCC output by the power management circuit according to the value of the second DC voltage Uo, so that the first DC voltage VCC matches the impedance change and the second DC voltage Uo reaches the reference value. The feedback circuit 1024 compares the first DC voltage VCC fed back by the feedback circuit 1024 with the amplified voltage U', and outputs the required regulated second DC voltage Uo to the power management circuit 1023, thereby achieving dynamic regulation of the first DC voltage VCC to match the impedance change.

[0046] In an example, Figure 4 As shown, the amplifier circuit 1021 includes: a first resistor R1; an operational amplifier, the negative input terminal of which is connected to the first resistor R1; a second resistor R2, connected in parallel between the negative input terminal and the output terminal of the operational amplifier; a first capacitor C1, connected in parallel across the second resistor R2, and the amplified voltage U' outputted from the output terminal of the operational amplifier is used as the output of the amplifier circuit 1021.

[0047] The follower circuit 1022 includes: a third resistor R3, a first end of which is connected to the output end of the amplifier to access the amplified voltage U'; a first diode D1, a positive electrode of which is connected to the second end of the third resistor R3; a fourth resistor R4, one end of which is connected between the second end of the third resistor R3 and the positive electrode of the first diode D1, and the other end is grounded GND; a fifth resistor R5, a first end of which is connected to the negative electrode of the first diode D1, and a second end is connected to the power management circuit 1023; a sixth resistor R6 and a seventh resistor R7, a first end of the sixth resistor R6 and a first end of the seventh resistor R7 are both connected between the second end of the fifth resistor R5 and the power management circuit 1023, the second end of the sixth resistor R6 is connected to the regulated first DC voltage VCC, and the second end of the seventh resistor is grounded.

[0048] The feedback circuit 1024 includes: an eighth resistor R8, a first end of which is connected to the regulated first DC voltage VCC; a ninth resistor R9, a first end of which is connected to the second end of the eighth resistor R8, and the second end of the ninth resistor R9 is grounded; a second capacitor C2, a first end of which is connected to the first end of the eighth resistor R8, and a second end of which is connected to the second end of the ninth resistor R9.

[0049] The power management circuit 1023 includes: a power management chip 1023a and its peripheral circuit 1023b, the peripheral circuit 1023b includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a thirteenth resistor R13, one end of which is connected to the power management chip 1023a, and a step-up and step-down circuit composed of four MOSFET tubes and a power inductor L, the power management chip 1023a can output a step-up or step-down voltage, the four MOSFET tubes are turned on and off according to the control of the power management chip 1023a, the current is adjusted through the power inductor, and the first DC voltage VCC is output. The other ends of the tenth resistor R10 and the eleventh resistor R11 are respectively connected to the bases of the MOSFET tubes Q1 and Q2, the other ends of the twelfth resistor R12 and the thirteenth resistor R13 are connected to the bases of the MOSFET tubes Q3 and Q4, the MOSFET tube Q1 is connected to the switch power supply VCC_IN, and the MOSFET tube Q3 outputs the first DC voltage VCC.

[0050] In a specific implementation, the power management chip 1023a can adjust the first DC voltage VCC based on a preset transfer function relationship, where the preset transfer function relationship is used to describe the transfer relationship between the analog voltage input by the amplifier circuit 1021 and the first DC voltage VCC.

[0051] Based on the above example, the preset transfer function relationship is as follows: VCC=- *Ui+

[0052] In the formula, VCC represents the first DC voltage, Ui represents the analog voltage, and Uo represents the reference value of the second DC voltage. The first intermediate variable k 1 =- , The second intermediate variable k 2 =( )*(1+ ), The third intermediate variable k 3 = , The fourth intermediate variable k 4 = , The fifth intermediate variable k 5 = , R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 They respectively represent the resistance values ​​of the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor, the sixth resistor, the seventh resistor, the eighth resistor, and the ninth resistor.

[0053] In this example, the reference value of the second DC voltage determined by the power management chip 1023a is 1.2. Figure 4 The circuit composition shown in the figure has a transfer function between the first DC voltage VCC and the analog voltage Ui input by the amplifier circuit as follows: U'=Ui*(- )+VCC*( )*(1+ ) Uo=U'* * +VCC* =1.2 Uo=(k 1 *Ui+k 2 *VCC)k 3 k 4 +k 5 *VCC=k 1 k 2 k 3 *Ui+(k 2 k 3 k 4 +k 5 )*VCC=1.2 Therefore, VCC = - *Ui+ .

[0054] According to the specific resistance value of each resistor, k can be calculated. 1 , k 2 , k 3 , k 4 , k 5 The value of k 1 =-27, k 2 =1.6, k 3 =0.9, k 4 =0.6, k 5 =0.009, substituting into the above formula, we get: VCC=16.7*Ui+1.37 During the execution of the radiofrequency ablation surgery, a dynamic Ui is generated according to the dynamic impedance change, and a Uo that follows the change is generated according to Ui. According to the reference value of Uo, when the input VCC_IN is fixed, the power management chip 1023a dynamically drives the opening and closing of the MOSFET tubes Q1~Q4 to achieve boost or buck, so that when Uo reaches its reference value, VCC matches the current impedance change. For example, during the radiofrequency ablation surgery, Uo is affected by U' and VCC. When VCC is high, the first diode D1 is not turned on, and U' does not affect Uo; when VCC is low, the first diode D1 is turned on, and U' affects Uo. Therefore, U' and VCC jointly affect Uo, and dynamic adjustment of VCC matching the impedance change is achieved.

[0055] In some specific implementations, the correspondence between different analog voltages and the first DC voltage can be determined based on the aforementioned preset transfer function relationship. When the analog voltage Ui is input, the power management chip 1023a quickly determines the corresponding VCC value based on the correspondence, and then adjusts VCC to a value that matches the current impedance change by driving the MOSFET tubes Q1~Q4 on and off, and makes Uo reach its baseline value.

[0056] In one example, the analog voltage Ui output by the digital-to-analog conversion chip ranges from 0 to 3.3 V, and the first DC output voltage VCC ranges from 1.37 V to 55.1 V. After passing through the transformer and frequency selection circuit, the output peak voltage can reach 147 V. Assuming that the impedance of biological tissue is 40 Ω, according to the power formula P= , and get P max = =540W. Taking into account factors such as transformer and line heat loss, when the conversion efficiency is 80%, the output power will reach 540*80%=432W, that is, greater than 400W. Therefore, for the RF signal output with impedance changes, its RF power can meet the high power requirement of 400W.

[0057] This embodiment linearly adjusts the output signal according to the transfer function relationship, has a rapid response, few circuit components, and high reliability. The range of the first DC output voltage VCC can also be flexibly adjusted by changing the resistance value of each resistor in the DC voltage output unit 102. When the rated power of the RF source needs to be changed, the resistance value can be easily adjusted, and VCC can be further adjusted, so it is suitable for multiple applications.

[0058] In some embodiments, the DC voltage output unit 102 also includes a protection circuit 1025 connected to the power management circuit 1023 and the transformer 103, for detecting line power and cutting off the output of the first DC voltage matching the impedance change when the line power exceeds the set power.

[0059] In this embodiment, the output of the first DC voltage is controlled by detecting the line power, thereby controlling the normal output and cutoff of the radio frequency signal, thereby achieving the effect of protecting the components in the circuit.

[0060] In some specific implementations, such as Figure 5 As shown, the protection circuit 1025 includes: The detection circuit 1025a is connected to the power management circuit 1023; The switch circuit 1025b is connected to the detection circuit 1025a; The detection circuit 1025a is used to: detect the line power based on the first DC voltage VCC output by the power management circuit 1023; drive the switch circuit 1025b to cut off the output of the first DC voltage VCC when the line power exceeds the set power; and drive the switch circuit 1025b to output the first DC voltage when the line power does not exceed the set power. In order to distinguish the first DC voltage of the input and output of the protection circuit 1025 to avoid unclear circuit connection, Figure 5 VCC_OUT in FIG. 1 is used to represent the first DC voltage output by the protection circuit 1025 .

[0061] In this embodiment, line power detection is implemented through a detection circuit, and then the output and cutoff of the first DC voltage are implemented through a driving switch circuit 1025b, so as to achieve a rapid cutoff response to power anomalies and avoid component damage caused by excessive line power.

[0062] In an example, Figure 5As shown, the detection circuit 1025a includes a monitoring chip and a fourteenth resistor R14, a fifteenth resistor R15 and a sixteenth resistor R16 arranged in its periphery, wherein the fourteenth resistor R14 is a current sensing resistor, one end of R14 is connected to the first DC voltage VCC output by the power management circuit 1023, R14 is connected to the monitoring chip and the switch circuit 1025b respectively, the fifteenth resistor R15 and the sixteenth resistor R16 are connected in series, that is: one end of R15 is connected to one end of R16, the monitoring chip is also connected to the connecting line between R15 and R16, the other end of R16 is grounded, and the other end of R15 is connected to the switch circuit 1025b.

[0063] The switch circuit 1025b includes: a seventeenth resistor R17, one end of which is connected to the monitoring chip; a transistor Q5, a base of which is connected to the other end of R17, and an emitter of which is grounded; an eighteenth resistor R18, one end of which is connected to the collector of the transistor Q5, and the other end of which is connected to the detection circuit 1025a; a third capacitor C3, one end of which is grounded, and the other end of which is connected to the collector of the transistor Q5; a nineteenth resistor R19, one end of which is connected to the other end of the third capacitor C3; a thyristor Q6, one end of which is connected to the detection circuit 10 25a and the other end of the nineteenth resistor R19; a voltage regulator D2, one end of which is connected to the detection circuit 1025a; a twentieth resistor R20, one end of which is connected to the detection circuit 1025a; a switch tube Q7, a source of which is connected to the detection circuit 1025a, and a drain of which outputs a first DC voltage VCC_OUT; a twenty-first resistor R21, one end of which is connected to the other end of the thyristor Q6, the other end of the voltage regulator D2, the other end of the twentieth resistor R20 and the gate of the switch tube Q7, and the other end of which is grounded.

[0064] The monitoring chip detects the voltage value U and current value I of the circuit in real time, and calculates the circuit power value P according to the power formula P=UI. When the circuit power value P exceeds the set power, the output of the control switch Q7 is turned off to protect the safe use of the component, and at the same time, a control signal to turn off the RF output is sent to the host computer. Based on the control signal, the RF ablation screen displays power abnormality and alarms. When protection occurs, the operator needs to turn off the RF source board and power it on again so that the RF source board can continue to work.

[0065] The specific implementation method is: the first DC output voltage VCC flows through the current sensing resistor R14, generating a voltage drop, and the monitoring chip collects the voltage drop in real time, and calculates the DC output current in real time according to Ohm's law. The DC output voltage passes through the voltage-dividing resistor network composed of R15 and R16, generating a voltage on R16, and the monitoring chip collects the voltage in real time. Since the line power is above 400W, resistors R18 and R19 need to use high-power resistors, and Q6 uses thyristors, which have the characteristics of fast response and high conversion efficiency. According to the power calculation formula P=UI, the monitoring chip refreshes the line power value in real time. During normal operation, the monitoring chip outputs a high level, the transistor Q5 is turned on, the thyristor Q6 is turned off, the voltage regulator D2 generates a voltage drop, the switch tube Q7 is turned on, and the first DC voltage (VCC_OUT) is output normally. If the line power exceeds the set power of the monitoring chip, the monitoring chip outputs a low level, the transistor Q5 is turned off, the thyristor Q6 is turned on, the voltage regulator D2 is short-circuited, the switch tube Q7 is no longer turned on, VCC_OUT has no output, and the RF power is no longer output.

[0066] In some embodiments, the transformer TR1 is used to convert the first DC voltage VCC_OUT matched with the impedance into a peak voltage required by the target RF power by adjusting the turns ratio.

[0067] In a specific implementation, the transformation ratio of the transformer TR1 can be determined by the required transformation ratio and inductance value according to the target RF power requirement and the corresponding peak voltage under the standard impedance.

[0068] In this embodiment, the transformer can convert the first DC voltage VCC_OUT that matches the impedance into the peak voltage required for the higher target RF power by adjusting the turns ratio, thereby realizing the output of the RF signal. Therefore, based on the amplification of the first DC voltage by the transformer, the target RF power value is improved compared with the traditional RF ablation device, meeting the high-power requirements of the RF ablation surgery, thereby improving the RF ablation treatment effect.

[0069] In some embodiments, the RF signal output unit 104 includes: The frequency selection circuit 1041 is connected to the secondary side of the transformer 103 and is used to convert the PWM square wave signal output by the radio frequency signal generating unit 101 into a sine wave signal; The RF signal output module 1042 is connected to the frequency selection circuit 1041 and is used to superimpose the peak voltage on the sine wave signal to generate a RF signal with a target RF power and output the RF signal.

[0070] In one example, the frequency selection circuit can be an LC frequency selection circuit. The number of winding turns of the power inductor L can be determined according to the peak voltage and the capacitance in the LC frequency selection circuit, and the winding is made of heat-resistant material, and the inductor generates little heat. The transformer TR1 changes the DC voltage VCC_OUT into the peak voltage required for the target RF power output by changing the transformation ratio, and the LC frequency selection circuit changes the PWM square wave signal transmitted by the switch tubes Q8 and Q9 into the sine wave signal required for the target RF power output. The sine wave is relatively safe for biological tissues.

[0071] Specifically, the original PWM square wave signal is electrically isolated and amplified by the PWM circuit 1012 to obtain the PWM square wave signal required by the radio frequency ablation device, and the PWM square wave signal is converted into a sinusoidal wave signal that is relatively safe for biological tissue by the frequency selection circuit 104. The aforementioned peak voltage is further superimposed on the sinusoidal wave signal to generate a radio frequency signal of the target radio frequency power, thereby achieving accurate output of the radio frequency signal, and the radio frequency signal acts on the target tissue.

[0072] The components required for the device of this embodiment can be integrated into a circuit board. The target RF power can reach 400W under standard load, which exceeds the output power of the commonly used RF source in the prior art. In addition, the power output changes smoothly, the size is small, the conversion efficiency is high, and the adaptability is wider.

[0073] Embodiment 2: This embodiment provides a radiofrequency ablation apparatus, comprising the radiofrequency signal generating device of the above embodiment.

[0074] The specific implementation of the radio frequency signal generating device refers to the above-mentioned embodiment and will not be described again here.

[0075] By adopting the RF signal generating device of the aforementioned embodiment, the RF ablation device can timely adjust the RF signal according to the impedance change of the target ablation tissue during the RF ablation operation, effectively improving the effect of the RF ablation operation and preventing the risks of carbonization and burns of biological tissues.

[0076] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present invention, and that in actual applications, various changes may be made in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A radio frequency signal generating device, characterized in that: include: A radio frequency signal generating unit, used for generating a PWM signal; A DC voltage output unit, configured to obtain an analog voltage generated based on an impedance change of a target ablation tissue, and output a first DC voltage matching the impedance change based on the analog voltage; A transformer, the primary side of which is connected to the RF signal generating unit and the DC voltage output unit, and the transformer is used to convert the first DC voltage into a peak voltage required by the target RF power; A radio frequency signal output unit is connected to the secondary side of the transformer, and is used to superimpose the peak voltage on the PWM signal to generate a radio frequency signal of a target radio frequency power and output the radio frequency signal.

2. The radio frequency signal generating device according to claim 1, characterized in that: The radio frequency signal generating unit comprises: A radio frequency control module, used to generate an original PWM square wave signal; A PWM circuit is connected to the radio frequency control module, and is used for electrically isolating and amplifying the original PWM square wave signal and then outputting it.

3. The radio frequency signal generating device according to claim 2, characterized in that: The PWM circuit comprises: An anti-interference isolation chip, used for electrically isolating and amplifying the original PWM square wave signal; A push-pull circuit is connected to the anti-interference isolation chip, wherein the push-pull circuit includes two switch tubes that work alternately under the drive of the anti-interference isolation chip, and the push-pull circuit is used to output a PWM square wave through the alternate work of the two switch tubes.

4. The radio frequency signal generating device according to claim 1, characterized in that: The DC voltage output unit comprises: an amplifying circuit, used for acquiring and amplifying an analog voltage generated based on impedance changes of a target ablation tissue; A follower circuit, connected to the amplifying circuit, and configured to output a second DC voltage according to the analog voltage; a power management circuit connected to the follower circuit, and configured to adjust a first DC voltage output by the power management circuit according to the second DC voltage, so that the first DC voltage matches the impedance change and the second DC voltage reaches a reference value; A feedback circuit is connected to the amplifying circuit and the power management circuit and is used for feeding back the regulated first DC voltage.

5. The radio frequency signal generating device according to claim 4, characterized in that: The first DC voltage output by the power management circuit is adjusted based on a preset transfer function relationship, where the preset transfer function relationship is used to describe a linear relationship between the analog voltage and the first DC voltage.

6. The radio frequency signal generating device according to claim 1, characterized in that: The transformer is used for converting a first DC voltage matching the impedance into a peak voltage required by a target radio frequency power by adjusting a turns ratio.

7. The radio frequency signal generating device according to claim 4, characterized in that: The DC voltage output unit also includes: a protection circuit connected to the power management circuit and the transformer, used to detect line power and cut off the output of the first DC voltage matching the impedance change when the line power exceeds the set power.

8. The radio frequency signal generating device according to claim 7, characterized in that: The protection circuit comprises: A detection circuit connected to the power management circuit; A switch circuit connected to the detection circuit; The detection circuit is used for: detecting line power based on a first DC voltage matching the impedance change; When the line power exceeds the set power, the switch circuit is driven to cut off the output of the first DC voltage matching the impedance change; and when the line power does not exceed the set power, the switch circuit is driven to output the first DC voltage matching the impedance change.

9. The radio frequency signal generating device according to claim 2, characterized in that: The radio frequency signal output unit comprises: A frequency selection circuit, connected to the secondary side of the transformer, for converting the PWM square wave signal output by the radio frequency signal generating unit into a sine wave signal; The radio frequency signal output module is connected to the frequency selection circuit and is used to superimpose the peak voltage on the sine wave signal to generate a radio frequency signal of a target radio frequency power and output the radio frequency signal.

10. A radiofrequency ablation apparatus, characterized in that: The invention comprises the radio frequency signal generating device according to any one of claims 1 to 9.

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