Power amplification circuit and radio frequency steam ablation equipment

Abstract

The utility model provides a power amplification circuit and radio frequency steam ablation equipment, relates to the technical field of medical equipment, is used for solving the technical problems that in the prior art, a power amplification circuit in the radio frequency steam ablation equipment is large in switching loss, complex in control and difficult in synchronization, and comprises a zero-voltage switch module and a resonance filtering module, the zero-voltage switch module controls a signal to drive the controllable switch to be switched on and switched off periodically, and the input direct current is converted into pulse current; a resonant element in the zero-voltage switch module is used for enabling the voltage at the two ends of the zero-voltage switch to approach to zero when the zero-voltage switch is switched on or switched off; and the resonant filtering module converts the pulse current into a sinusoidal current with a target frequency, and transmits the sinusoidal current to the radio frequency steam ablation catheter, so that the power amplification circuit can realize zero-voltage turn-on or turn-off, the switching loss in the power amplification circuit is reduced, the zero-voltage switch module only needs to be provided with a controllable switch, and the control is relatively simple.

Description

Technical Field

[0001] This utility model relates to the field of medical equipment technology, and in particular to a power amplifier circuit and a radiofrequency vapor ablation device. Background Technology

[0002] With the development of medical technology, radiofrequency vapor ablation is a novel technology combining radiofrequency ablation and vapor ablation. During radiofrequency vapor ablation, the device delivers radiofrequency energy and saline solution to the tip of the ablation catheter, generating hot steam. This steam ablates the target tissue to achieve the therapeutic effect. The device includes a radiofrequency power amplifier circuit, which amplifies the current of a specific radiofrequency waveform to deliver high power.

[0003] Currently, power amplifier circuits used for radio frequency (RF) output typically employ high-frequency switching devices. Lower-power power amplifier circuits use a single switching device, forming a conventional single-transistor power amplifier circuit. Higher-power power amplifier circuits use multiple switching devices, forming a conventional push-pull dual-transistor power amplifier circuit, or a conventional H-bridge four-transistor power amplifier circuit, etc. Since medical radio frequency refers to frequencies from hundreds of kilohertz to several megahertz, which are very high, significant switching losses occur during the switching process. This results in low efficiency and severe heat generation in the aforementioned conventional power amplifier circuits, thus affecting overall performance and reliability. Furthermore, the control of the H-bridge four-transistor power amplifier circuit is quite complex, and synchronization is difficult. In summary, the conventional schemes for power amplifier circuits used for RF output suffer from high switching losses, complex control, and difficult synchronization, which are problems that urgently need to be solved. Utility Model Content

[0004] The purpose of this invention is to provide a power amplifier circuit and a radio frequency vapor ablation device to solve the technical problems of high switching losses, complex control, and difficult synchronization of power amplifier circuits.

[0005] In a first aspect, this utility model provides a power amplifier circuit for radio frequency vapor ablation equipment, comprising: a zero-voltage switching module and a resonant filter module; the zero-voltage switching module includes a controllable switch and a resonant element.

[0006] The input terminal of the zero-voltage switch module is connected to an external DC power supply, and the control terminal of the switch in the zero-voltage switch module is connected to an external control module; the output terminal of the zero-voltage switch module is connected to the input terminal of the resonant filter module, and the first and second output terminals of the resonant filter module are respectively connected to an external radiofrequency vapor ablation conduit.

[0007] The zero-voltage switch module is used to drive the controllable switch to periodically turn on and off according to the control signal input from the control module, converting the DC power input into pulse current; the resonant element in the zero-voltage switch module is used to make the voltage across the zero-voltage switch approach zero when the zero-voltage switch is turned on or off.

[0008] The resonant filter module is used to filter out harmonic components in the pulse current and convert the pulse current into a sinusoidal current at the target frequency, which is then transmitted to the radiofrequency vapor ablation catheter.

[0009] Optionally, the zero-voltage switching module includes: a first transformer, a first PMOS transistor, a first capacitor, a diode, and a MOS transistor driver module;

[0010] The first primary side terminal of the first transformer is connected to the output terminal of the DC power supply, and the second primary side terminal of the first transformer is connected to the drain of the first PMOS transistor and the cathode of the diode, respectively; the first secondary side terminal and the second secondary side terminal of the first transformer are connected to the resonant filter module, respectively.

[0011] The positive terminal of the diode is connected to ground; the first capacitor is connected in parallel with the diode;

[0012] The source of the first PMOS transistor is connected to ground, and the gate of the first PMOS transistor is connected to the control module via the MOS transistor driving module.

[0013] Optionally, the resonant filter module includes: a first series resonant module and a second series resonant module;

[0014] The first secondary side terminal of the first transformer is connected to the radio frequency vapor ablation conduit via the first series resonant module.

[0015] The second secondary side terminal of the first transformer is connected to the radio frequency vapor ablation conduit via the second series resonant module.

[0016] Optionally, the first series resonant module includes: a first inductor, a second capacitor, a third capacitor, and a fourth capacitor;

[0017] The first secondary terminal of the first transformer is connected to the radio frequency vapor ablation conduit via the first inductor, the second capacitor, and the third capacitor in sequence.

[0018] The fourth capacitor is connected in parallel with the third capacitor.

[0019] Optionally, the power amplifier circuit may also include: a compensation module;

[0020] The compensation module is connected in parallel between the first and second output terminals of the resonant filter module; the compensation module is used to cancel the parasitic parameters of the radiofrequency vapor ablation catheter so that the load of the power amplifier circuit is a resistive load.

[0021] Optionally, the compensation module includes: a compensation capacitor;

[0022] The first end of the compensation capacitor is connected to the first output terminal of the resonant filter module, and the second end of the compensation capacitor is connected to the second output terminal of the resonant filter module.

[0023] Optionally, the power amplifier circuit may also include: a voltage acquisition module and / or a current acquisition module;

[0024] The voltage acquisition module is connected in parallel between the first and second output terminals of the resonant filter module, and the voltage acquisition module is connected to the control module.

[0025] The current acquisition module is connected in series between the first output terminal of the resonant filter module and the radiofrequency vapor ablation conduit, and the current acquisition module is connected to the control module.

[0026] Optionally, the voltage acquisition module includes: a first resistor, a second resistor, a third resistor, and a second transformer;

[0027] The first primary side terminal of the second transformer is connected to the first output terminal of the resonant filter module via the first resistor. The second primary side terminal of the second transformer is connected to the second output terminal of the resonant filter module via the second resistor. The first secondary side terminal of the second transformer is connected to ground. The second secondary side terminal of the second transformer is connected to the control module.

[0028] The third resistor is connected in parallel between the first and second secondary terminals of the second transformer.

[0029] Optionally, the current acquisition module includes: a fourth resistor and a third transformer;

[0030] The first primary side terminal of the third transformer is connected to the first output terminal of the resonant filter module, the second primary side terminal of the third transformer is connected to the radio frequency vapor ablation conduit, the first secondary side terminal of the third transformer is connected to ground, and the second secondary side terminal of the third transformer is connected to the control module.

[0031] The fourth resistor is connected in parallel between the first and second secondary terminals of the third transformer.

[0032] Secondly, this utility model provides a radiofrequency vapor ablation device, comprising: a main unit and a radiofrequency vapor ablation catheter; the main unit includes a control module, a saline infusion device and the aforementioned power amplifier circuit;

[0033] The control module is connected to the saline infusion device and the power amplifier circuit respectively; the input terminal of the power amplifier circuit is connected to an external DC power supply, and the output terminal of the power amplifier circuit is connected to the radiofrequency steam ablation catheter; the output terminal of the saline infusion device is connected to the radiofrequency steam ablation catheter.

[0034] In the power amplifier circuit provided by this utility model, a controllable switch and a resonant element are set in the zero-voltage switch module. The resonant element ensures that the voltage across the zero-voltage switch is zero when the zero-voltage switch is turned on or off, enabling the zero-voltage switch to be turned on or off at zero voltage. This reduces switching losses in the power amplifier circuit and lowers the heating temperature of the power amplifier circuit under high-frequency, high-voltage conditions. Furthermore, the zero-voltage switch module only requires one controllable switch, making control relatively simple. In addition, the resonant filter module filters out harmonic components in the pulse current and converts the pulse current into a sinusoidal current at the target frequency. This ensures stable transmission of radio frequency energy and avoids uneven ablation caused by harmonic interference, providing a reliable and stable high-frequency energy output foundation for the radio frequency vapor ablation catheter. Attached Figure Description

[0035] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 A schematic diagram of the first circuit structure of the power amplifier circuit provided in the embodiment of this utility model;

[0037] Figure 2 A schematic diagram of a second circuit structure for a power amplifier circuit provided in an embodiment of this utility model;

[0038] Figure 3 A schematic diagram of a third circuit structure for a power amplifier circuit provided in an embodiment of this utility model;

[0039] Figure 4 Equivalent circuit diagram of the output terminal of the power amplifier circuit provided in the embodiment of this utility model;

[0040] Figure 5 A schematic diagram of the fourth circuit structure of the power amplifier circuit provided in this embodiment of the utility model;

[0041] Figure 6 A schematic diagram of the circuit structure of the radio frequency vapor ablation device provided in this embodiment of the utility model.

[0042] Icons: 100 - Power amplifier circuit; 110 - Zero-voltage switching module; 120 - Resonant filter module; 121 - First series resonant module; 122 - Second series resonant module; 130 - Compensation module; 140 - Voltage acquisition module; 150 - Current acquisition module; T1 - First transformer; T2 - Second transformer; T3 - Third transformer; Q1 - First PMOS transistor; C1 - First capacitor; D1 - Diode; 111 - MOS transistor drive module; L1 - First inductor; C2 - Second capacitor; C3 - Third capacitor; C4 - Fourth capacitor; L2 - Second inductor; C5 - Fifth capacitor; C6 - Sixth capacitor; C7 - Seventh capacitor; Cp - Compensation capacitor; R1 - First resistor; R2 - Second resistor; R3 - Third resistor; R4 - Fourth resistor; 200 - Radiofrequency vapor ablation device; 210 - Main unit; 220 - Radiofrequency vapor ablation catheter; 211 - Control module; 212 - Saline infusion device. Detailed Implementation

[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0044] This utility model embodiment provides a power amplifier circuit, see reference. Figure 1 As shown, the power amplifier circuit 100 includes at least: a zero-voltage switching module 110 and a resonant filter module 120; the zero-voltage switching module 110 includes a controllable switch and a resonant element;

[0045] The input terminal of the zero-voltage switch module 110 is connected to an external DC power supply, and the control terminal of the zero-voltage switch in the zero-voltage switch module 110 is connected to an external control module; the output terminal of the zero-voltage switch module 110 is connected to the input terminal of the resonant filter module 120, and the first and second output terminals of the resonant filter module 120 are respectively connected to an external radiofrequency vapor ablation conduit.

[0046] The zero-voltage switch module 110 is used to drive the controllable switch to periodically turn on and off according to the control signal input from the control module, and to convert the DC power input from the DC power supply into pulse current; the resonant element in the zero-voltage switch module 110 is used to make the voltage across the zero-voltage switch approach zero when the zero-voltage switch is turned on or off.

[0047] The resonant filter module 120 is used to filter out the harmonic components in the pulse current and convert the pulse current into a sinusoidal current of the target frequency, and transmit the sinusoidal current to the radiofrequency vapor ablation catheter.

[0048] exist Figure 1 In the power amplifier circuit 100 shown, the external DC power supply is an adjustable high-voltage DC power supply, and the control module can be a microprocessor. The zero-voltage switching module 110 includes a circuit consisting of a controllable switch and a resonant element. The controllable switch can be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The resonant element includes at least one inductive element and at least one capacitive element. The inductive and capacitive elements can generate series resonance or parallel resonance. The controllable switch in the zero-voltage switching module 110 can achieve zero-voltage turn-on and zero-voltage turn-off. Specifically, before the controllable switch is turned on, the voltage across the controllable switch is resonated to zero through the resonant element, achieving zero-voltage turn-on. When the controllable switch is turned off, the resonant circuit slows down the rise rate of the voltage across the controllable switch, bringing the forward voltage across the controllable switch close to zero, achieving zero-voltage turn-off. After receiving the control signal from the control module, the zero-voltage switching module 110 drives the controllable switch to periodically turn on and off according to the control signal. During the periodic on and off of the controllable switch, the DC power input from the DC power supply is converted into pulse current. The resonant filter module 120 is used to filter out the harmonic components in the pulse current, allowing only components with the same or close resonant frequency as the resonant filter module 120 to pass through without loss and almost all of them are loaded into the subsequent circuit, thereby converting the pulse current into a sinusoidal current of the target frequency. The target frequency is the resonant frequency of the resonant filter module 120, which is also the operating frequency required by the radiofrequency vapor ablation catheter.

[0049] In this way, by incorporating a controllable switch and a resonant element into the zero-voltage switching module, the resonant element ensures that the voltage across the controllable switch is zero when it is turned on or off. This allows the controllable switch to be turned on or off at zero voltage, reducing switching losses in the power amplifier circuit and lowering the heating temperature of the power amplifier circuit under high-frequency, high-voltage conditions. Furthermore, the zero-voltage switching module only requires one controllable switch, making control relatively simple and eliminating synchronization control issues. In addition, the resonant filter module filters out harmonic components in the pulse current and converts the pulse current into a sinusoidal current at the target frequency, ensuring stable radio frequency energy transmission and avoiding uneven ablation caused by harmonic interference. This provides a reliable and stable high-frequency energy output foundation for the radio frequency vapor ablation catheter.

[0050] In practical implementation, the zero-voltage switching module in the power amplifier circuit provided in this application has various structures to achieve its function, see reference. Figure 2As shown, the zero-voltage switching module 110 may include: a first transformer T1, a first PMOS transistor Q1, a first capacitor C1, a diode D1, and a MOS transistor driving module 111;

[0051] The first primary side terminal of the first transformer T1 is connected to the output terminal of the DC power supply, and the second primary side terminal of the first transformer T1 is connected to the drain of the first PMOS transistor Q1 and the negative terminal of the diode D1, respectively; the first secondary side terminal and the second secondary side terminal of the first transformer T1 are connected to the resonant filter module 120, respectively.

[0052] The positive terminal of diode D1 is connected to ground; the first capacitor C1 is connected in parallel with diode D1;

[0053] The source of the first PMOS transistor Q1 is connected to ground, and the gate of the first PMOS transistor Q1 is connected to the control module via the MOS transistor driving module 111.

[0054] exist Figure 2 In the power amplifier circuit 100 shown, the magnetizing inductance of the first transformer T1 and the first capacitor C1 constitute a resonant element. The first PMOS transistor Q1 serves as a controllable switch. The resonant frequency of the resonant element formed by the magnetizing inductance of the first transformer T1 and the first capacitor C1 needs to be matched with the off-frequency and duty cycle of the first PMOS transistor Q1, so that when the drain voltage of the MOS transistor approaches 0, the drive signal of the gate of the MOS transistor becomes high and low at the same time, thereby realizing zero-voltage switching. The diode D1 is used to discharge the current flowing through the zero-voltage switching module 110 when the parameters of the electronic components deviate, ensuring that the drain voltage of the MOS transistor is always non-negative. The first transformer T1 can not only resonate with the first capacitor C1 through its magnetizing inductance, but also play an isolation role, electrically isolating the zero-voltage switching module 110 from the DC power supply, ensuring that the radio frequency vapor ablation catheter connected to the zero-voltage switching module 110 meets the electrical safety requirements when in contact with the human body. The MOS transistor driving module 111 may include components such as a driving chip, capacitors, and resistors. The driving chip needs to be determined according to the operating conditions of the first PMOS transistor, and the location and number of capacitors and resistors need to be determined according to the driving chip.

[0055] In this way, the single-tube structure composed of the first PMOS transistor Q1 makes the circuit structure more compact; the magnetizing inductance of the first transformer T1 and the first capacitor C1 form a resonant element, realizing zero-voltage turn-on and turn-off of the first PMOS transistor Q1, reducing switching losses in the circuit and reducing heat generation; the first transformer T1 has the dual function of providing resonant inductance and isolation element, making the circuit compact and simple, and improving the safety and reliability of the circuit.

[0056] In one possible implementation, Figure 2The first capacitor C1 can also be replaced by multiple capacitors connected in parallel, which can more accurately achieve the required capacitance value. Thus, without changing the excitation inductance of the first transformer T1, the resonant frequency of the resonant element in the zero-voltage switching module can be selected more accurately.

[0057] In practical implementation, the resonant filter module in the power amplifier circuit provided in this application has various structures to achieve its function, see reference. Figure 2 As shown, the zero-voltage switching module 110 may include: a first series resonant module 121 and a second series resonant module 122;

[0058] The first secondary side terminal of the first transformer T1 is connected to the radio frequency vapor ablation conduit via the first series resonant module 121;

[0059] The second secondary side terminal of the first transformer T1 is connected to the radio frequency vapor ablation conduit via the second series resonant module 122.

[0060] exist Figure 2 In the power amplifier circuit 100 shown, the first series resonant module 121 and the second series resonant module 122 have the same structure. The secondary side of the first transformer T1, the first series resonant module 121, the second series resonant module 122, and the radiofrequency vapor ablation catheter form a series-connected loop. The total inductance of the first series resonant module 121 and the total inductance of the second series resonant module 122 are connected in series to obtain the total inductance of the resonant filter module 120. The total capacitance of the first series resonant module 121 and the total capacitance of the second series resonant module 122 are connected in series to obtain the total capacitance of the resonant filter module 120. The total inductance and total capacitance of the resonant filter module 120 resonate in series, and the resonant frequency of the total inductance and total capacitance resonating in series is the target frequency. The bipolar accessory in the radiofrequency vapor ablation catheter needs to be connected to a capacitor, and the capacitance does not exceed 50nF. Therefore, the total capacitance of the resonant filter module 120 is less than 50nF to meet the safety requirements of the bipolar accessory in the connected radiofrequency vapor ablation catheter.

[0061] By dividing the zero-voltage switching module into a first series resonant module and a second series resonant module with identical structures, and symmetrically positioning them at the output of the zero-voltage switching module, the voltage amplitude output by the first transformer T1 can be fully utilized. Furthermore, the resonant filter module, composed of inductors and capacitors, has very low losses, thus reducing circuit heat generation. In addition, it effectively reduces performance fluctuations caused by component inconsistencies or minor differences in the manufacturing process. When the parameters of one component deviate from the design value, the other symmetrically positioned component can partially compensate for this deviation, thereby maintaining the stability of the overall resonant frequency. This symmetrical design not only helps maintain the stability of circuit performance but also improves the circuit's reliability and fault tolerance. In power amplifier circuits, this design is of great significance for ensuring stable RF energy transmission and avoiding uneven ablation.

[0062] For details, please refer to Figure 2 As shown, the first series resonant module 121 includes: a first inductor L1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4;

[0063] The first secondary side terminal of the first transformer T1 is connected to the radio frequency vapor ablation conduit via the first inductor L1, the second capacitor C2, and the third capacitor C3 in sequence; the fourth capacitor C4 is connected in parallel with the third capacitor C3.

[0064] Since the first series resonant module 121 and the second series resonant module 122 can adopt the same structure, see [reference] Figure 2 As shown, the second series resonant module 122 includes: a second inductor L2, a fifth capacitor C5, a sixth capacitor C6, and a seventh capacitor C7;

[0065] The first secondary side terminal of the first transformer T1 is connected to the radiofrequency vapor ablation conduit via the second inductor L2, the fifth capacitor C5 and the sixth capacitor C6 in sequence.

[0066] The seventh capacitor C7 is connected in parallel with the sixth capacitor C6.

[0067] exist Figure 2In the power amplifier circuit 100 shown, the first inductor L1 and the second inductor L2 have the same inductance value; the second capacitor C2 and the fifth capacitor C5 have the same capacitance value; the third capacitor C3 and the sixth capacitor C6 have the same capacitance value; and the fourth capacitor C4 and the seventh capacitor C7 have the same capacitance value. The total inductance of the resonant filter module 120 is the inductance value of the first inductor L1 and the second inductor L2 connected in series; the total capacitance of the resonant filter module 120 is the first equivalent capacitance of the third capacitor C3 and the fourth capacitor C4 connected in parallel, the second equivalent capacitance of the third capacitor C3 and the fourth capacitor C4 connected in parallel, and the capacitance value of the second capacitor C2 and the fifth capacitor C5 connected in series. The total inductance and total capacitance form an LC series resonance, allowing components with a frequency consistent with or close to the target resonant frequency to pass through without loss and be loaded onto the subsequent radio frequency vapor ablation conduit. Components with a frequency significantly different from the target resonant frequency are voltage-divided by the various inductors and capacitors and are hardly loaded onto the subsequent circuit, thus realizing the filtering function of the resonant filter module 120. By connecting the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 in series and parallel to form the total capacitance of the resonant filter module 120, a more accurate capacitance value can be obtained. Thus, with the first inductor L1 and the second inductor L2 remaining unchanged, the desired target frequency can be selected more accurately.

[0068] In one possible implementation, see [reference] Figure 3 As shown, in order to avoid the reactive power generated by the parasitic parameters of the radiofrequency vapor ablation catheter reducing the efficiency of the power amplifier circuit 100, the power amplifier circuit 100 also includes a compensation module 130.

[0069] The compensation module 130 is connected in parallel between the first and second output terminals of the resonant filter module 120; the compensation module 130 is used to cancel the parasitic parameters of the radiofrequency vapor ablation catheter so that the load of the power amplifier circuit 100 is a resistive load.

[0070] like Figure 3 and Figure 4As shown, the radiofrequency vapor ablation conduit, in addition to its equivalent resistance Ro, also contains parasitic inductance Lo1 and parasitic capacitance Co1. Due to the relatively long length of the radiofrequency vapor ablation conduit, the parasitic inductance Lo1 of the longer connecting wires is more significant than the parasitic capacitance Co1. The equivalent result of both parasitic inductance Lo1 and parasitic capacitance Co1 is a parasitic equivalent inductance Lo connected in series with the equivalent resistance. The series equivalent resistance Ro and parasitic equivalent inductance Lo form a parasitic branch. One end of the parasitic branch is connected to the first output terminal of the resonant filter module 120, and the other end is connected to the second output terminal of the resonant filter module 120. The compensation module 130 is connected in parallel with the parasitic branch. The compensation module 130 uses internally provided capacitive elements to cancel the parasitic equivalent inductance Lo in the parasitic branch, thereby making the load connected in the power amplifier circuit 100 a resistive load.

[0071] In practical implementation, the compensation module in the power amplifier circuit provided in this application has various structures to achieve its function, see reference. Figure 3 As shown, the compensation module 130 may include: a compensation capacitor Cp;

[0072] The first end of the compensation capacitor Cp is connected to the first output terminal of the resonant filter module 120, and the second end of the compensation capacitor Cp is connected to the second output terminal of the resonant filter module 120.

[0073] In practical applications, the equivalent circuit at the output of the power amplifier circuit, consisting of the compensation capacitor Cp and the parasitic branch, is as follows: Figure 4 As shown, the compensation capacitor Cp is connected in parallel with the parasitic branch, which consists of the series equivalent resistance Ro and the parasitic equivalent inductance Lo. The total impedance Z of the equivalent circuit at the output of this power amplifier circuit is:

[0074]

[0075] Where Z represents the total impedance of the equivalent circuit at the output terminal, ω represents the angular velocity, Cp represents the compensation capacitor, Lo represents the parasitic equivalent inductance, and Ro represents the equivalent resistance.

[0076] In order to offset the parasitic equivalent inductance Lo in the parasitic branch by using the compensation capacitor Cp, the value of the compensation capacitor Cp needs to satisfy the imaginary part of the total impedance Z of the equivalent circuit at the output terminal to be zero, so that the load of the power amplifier circuit 100 is a resistive load.

[0077] In one possible implementation, see [reference] Figure 5 As shown, in order to detect the power data output by the power amplifier circuit 100 in real time, the power amplifier circuit 100 also includes: a voltage acquisition module 140 and / or a current acquisition module 150.

[0078] The voltage acquisition module 140 is connected in parallel between the first and second output terminals of the resonant filter module 120, and the voltage acquisition module 140 is connected to the control module.

[0079] The current acquisition module 150 is connected in series between the first output terminal of the resonant filter module 120 and the radiofrequency vapor ablation catheter. The current acquisition module 150 is connected to the control module.

[0080] In practical applications, the voltage acquisition module 140 is used to acquire the output voltage of the power amplifier circuit 100 in real time, and then step down the output voltage to obtain a sampled voltage, which is then sent to the control module. The current acquisition module 150 is used to acquire the output current of the power amplifier circuit 100 in real time, and then adjusts the magnitude of the output current before sending it to the control module. The voltage acquisition module 140 can be composed of at least one voltage acquisition element selected from a voltage sampling resistor, a Hall voltage sensor, and a capacitive voltage sensor, as well as related components configured for the voltage acquisition element. The current acquisition module 150 can be composed of at least one voltage acquisition element selected from a Hall current sensor, a shunt resistor, and a Rogowski coil, as well as related components configured for the current acquisition element.

[0081] In practical implementation, the voltage acquisition module in the power amplifier circuit provided in this application has various structures to achieve its function, see reference. Figure 5 As shown, the voltage acquisition module 140 may include: a first resistor R1, a second resistor R2, a third resistor R3, and a second transformer T2;

[0082] The first primary side terminal of the second transformer T2 is connected to the first output terminal of the resonant filter module 120 via the first resistor R1. The second primary side terminal of the second transformer T2 is connected to the second output terminal of the resonant filter module 120 via the second resistor R2. The first secondary side terminal of the second transformer T2 is connected to ground. The second secondary side terminal of the second transformer T2 is connected to the control module.

[0083] The third resistor R3 is connected in parallel between the first and second secondary terminals of the second transformer T2.

[0084] exist Figure 5In the power amplifier circuit 100 shown, the first resistor R1 and the second resistor R2 are respectively connected between the two primary terminals of the second transformer T2 and the output terminal of the resonant filter module 120, acting as a voltage divider to reduce the high voltage output by the resonant filter module 120 to a suitable measurement level. The first resistor R1 and the second resistor R2 also limit the current input to the second transformer T2, preventing excessive current from damaging the circuit. The third resistor R3 is also used to adjust the high voltage output by the resonant filter module 120. The second transformer T2 is used for electrical isolation and voltage transformation based on its turns ratio. Compared with the traditional method of using a voltage sensor, the voltage acquisition module proposed in this application facilitates component adjustment according to circuit performance requirements and is also easy to calibrate. Performance requirements may include performance parameters, withstand voltage values, leakage current values, etc. Furthermore, due to the configuration of the second transformer T2, the voltage acquisition module 140 can also serve as an electrical isolation device.

[0085] Specifically, when the turns ratio of the second transformer T2 is K1, the sampling voltage can be determined by the following formula (2).

[0086]

[0087] Among them, U t22 U represents the sampled voltage. t21 R1 represents the output voltage of the power amplifier circuit, R2 represents the turns ratio of the second transformer, R3 represents the first resistor, R2 represents the second resistor, and R3 represents the third resistor.

[0088] In practical implementation, the current acquisition module in the power amplifier circuit provided in this application has various structures to achieve its function, see reference. Figure 5 As shown, the current acquisition module 150 may include: a fourth resistor R4 and a third transformer T3;

[0089] The first primary side terminal of the third transformer T3 is connected to the first output terminal of the resonant filter module 120, the second primary side terminal of the third transformer T3 is connected to the radio frequency vapor ablation conduit, the first secondary side terminal of the third transformer T3 is connected to ground, and the second secondary side terminal of the third transformer T3 is connected to the control module.

[0090] The fourth resistor R4 is connected in parallel between the first and second secondary terminals of the third transformer T3.

[0091] exist Figure 5In the power amplifier circuit 100 shown, the fourth resistor R4 is used to adjust the current input to the third transformer from the resonant filter module 120. The third transformer T3 is used for electrical isolation and current transformation according to its own turns ratio. Compared with the traditional method of using a current sensor, it is easier to adjust the components according to the performance requirements of the circuit and also easier to calibrate. In addition, due to the setting of the third transformer T3, the current acquisition module 150 can also serve as an electrical isolation function.

[0092] Specifically, when the turns ratio of the third transformer T3 is K2, the sampling current can be determined by the following formula (3).

[0093] I t32 =I t31 ·R4·K2 (3)

[0094] Among them, I t32 Indicates the sampling current, I t31 K1 represents the output current of the power amplifier circuit, K2 represents the turns ratio of the third transformer, and R4 represents the fourth resistor.

[0095] Based on the same concept, this utility model embodiment also provides a radiofrequency vapor ablation device 200, see reference. Figure 6 As shown, the radiofrequency vapor ablation device 200 includes at least: a main unit 210 and a radiofrequency vapor ablation catheter 220; the main unit 210 includes a control module 211, a saline infusion device 212 and the aforementioned power amplifier circuit 100;

[0096] The control module 211 is connected to the saline infusion device 212 and the power amplifier circuit 100 respectively; the input terminal of the power amplifier circuit 100 is connected to an external DC power supply, and the output terminal of the power amplifier circuit 100 is connected to the radiofrequency steam ablation catheter 220; the output terminal of the saline infusion device 212 is connected to the radiofrequency steam ablation catheter 220.

[0097] In practical applications, the saline infusion device 212 is used to provide saline solution to the radiofrequency steam ablation catheter 220. The power amplifier circuit 100 is connected to the electrode plate in the radiofrequency steam ablation catheter 220 and is used to provide a high-frequency current of the target frequency to the electrode plate so that the electrode heats the saline solution to generate steam. The control module 211 is used to control the saline infusion flow rate of the saline infusion device 212 and also to generate drive signals for the controllable switch in the power amplifier circuit 100. When the power amplifier circuit 100 includes a voltage acquisition module 140 and a current acquisition module 150, the host 210 is also equipped with an analog-to-digital conversion circuit. The analog-to-digital conversion circuit performs analog-to-digital conversion on the sampled voltage and sampled current respectively, and inputs the analog-to-digital converted sampled voltage and sampled current to the control module 211.

[0098] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0099] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this utility model without departing from the spirit and scope of the embodiments of this utility model. Therefore, if these modifications and variations to the embodiments of this utility model fall within the scope of the claims of this utility model and their equivalents, then this utility model also intends to include these modifications and variations.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A power amplification circuit, characterized by, A radiofrequency vapor ablation device includes: a zero-voltage switching module and a resonant filtering module; the zero-voltage switching module includes a controllable switch and a resonant element. The input terminal of the zero-voltage switch module is connected to an external DC power supply, and the control terminal of the zero-voltage switch in the zero-voltage switch module is connected to an external control module; the output terminal of the zero-voltage switch module is connected to the input terminal of the resonant filter module, and the first and second output terminals of the resonant filter module are respectively connected to an external radiofrequency vapor ablation conduit. The zero-voltage switch module is used to drive the controllable switch to periodically turn on and off according to the control signal input by the control module, and to convert the DC power input by the DC power supply into pulse current; the resonant element in the zero-voltage switch module is used to make the voltage across the zero-voltage switch approach zero when the zero-voltage switch is turned on or off. The resonant filter module is used to filter out the harmonic components in the pulse current and convert the pulse current into a sinusoidal current of the target frequency, and transmit the sinusoidal current to the radiofrequency vapor ablation catheter.

2. The power amplification circuit of claim 1, wherein, The zero-voltage switching module includes: a first transformer, a first PMOS transistor, a first capacitor, a diode, and a MOS transistor driving module; The first primary side terminal of the first transformer is connected to the output terminal of the DC power supply, and the second primary side terminal of the first transformer is connected to the drain of the first PMOS transistor and the cathode of the diode, respectively; the first secondary side terminal and the second secondary side terminal of the first transformer are connected to the resonant filter module, respectively. The positive terminal of the diode is connected to ground; the first capacitor is connected in parallel with the diode; The source of the first PMOS transistor is connected to ground, and the gate of the first PMOS transistor is connected to the control module via the MOS transistor driving module.

3. The power amplification circuit of claim 2, wherein, The resonant filtering module includes: a first series resonant module and a second series resonant module; The first secondary terminal of the first transformer is connected to the radio frequency vapor ablation conduit via the first series resonant module. The second secondary terminal of the first transformer is connected to the radio frequency vapor ablation conduit via the second series resonant module.

4. The power amplification circuit of claim 3, wherein, The first series resonant module includes: a first inductor, a second capacitor, a third capacitor, and a fourth capacitor; The first secondary terminal of the first transformer is connected to the radio frequency vapor ablation conduit via the first inductor, the second capacitor, and the third capacitor in sequence. The fourth capacitor is connected in parallel with the third capacitor.

5. The power amplification circuit according to any one of claims 1 to 4, characterized by, Also includes: Compensation module; The compensation module is connected in parallel between the first and second output terminals of the resonant filter module; the compensation module is used to cancel the parasitic parameters of the radiofrequency vapor ablation catheter so that the load of the power amplifier circuit is a resistive load.

6. The power amplification circuit of claim 5, wherein, The compensation module includes: a compensation capacitor; The first end of the compensation capacitor is connected to the first output end of the resonant filter module, and the second end of the compensation capacitor is connected to the second output end of the resonant filter module.

7. The power amplification circuit of claim 6, wherein, Also includes: Voltage acquisition module and / or current acquisition module; The voltage acquisition module is connected in parallel between the first and second output terminals of the resonant filter module, and the voltage acquisition module is connected to the control module. The current acquisition module is connected in series between the first output terminal of the resonant filter module and the radiofrequency vapor ablation catheter, and the current acquisition module is connected to the control module.

8. The power amplification circuit of claim 7, wherein, The voltage acquisition module includes: a first resistor, a second resistor, a third resistor, and a second transformer; The first primary side terminal of the second transformer is connected to the first output terminal of the resonant filter module via the first resistor; the second primary side terminal of the second transformer is connected to the second output terminal of the resonant filter module via the second resistor; the first secondary side terminal of the second transformer is connected to ground; and the second secondary side terminal of the second transformer is connected to the control module. The third resistor is connected in parallel between the first secondary side terminal and the second secondary side terminal of the second transformer.

9. The power amplification circuit of claim 7, wherein, The current acquisition module includes: a fourth resistor and a third transformer; The first primary side terminal of the third transformer is connected to the first output terminal of the resonant filter module, the second primary side terminal of the third transformer is connected to the radio frequency vapor ablation conduit, the first secondary side terminal of the third transformer is connected to ground, and the second secondary side terminal of the third transformer is connected to the control module. The fourth resistor is connected in parallel between the first secondary side terminal and the second secondary side terminal of the third transformer.

10. A radio frequency vapor ablation device, characterized by, include: A main unit and a radiofrequency vapor ablation catheter; the main unit includes a control module, a saline infusion device, and a power amplifier circuit as described in any one of claims 1-9; The control module is connected to the saline infusion device and the power amplifier circuit respectively; the input terminal of the power amplifier circuit is connected to an external DC power supply, and the output terminal of the power amplifier circuit is connected to the radiofrequency steam ablation catheter; the output terminal of the saline infusion device is connected to the radiofrequency steam ablation catheter.

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