Microwave ablation equipment
By designing a microwave ablation device with adjustable power source and power amplifier, flexible combination ablation between high and low frequency bands is achieved, solving the problem of insufficient flexibility of existing equipment, providing multi-dimensional adjustment of ablation parameters, and suitable for diverse tumor treatments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN INST OF ADVANCED TECH CHINESE ACAD OF SCI
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-21
AI Technical Summary
Existing microwave ablation equipment can only operate in a single frequency band or perform dual-frequency ablation between simple high and low frequency bands, which is not very flexible and makes it difficult to meet diverse ablation needs.
A microwave ablation device was designed, employing an adjustable power source and a power amplifier, including a frequency source, a switching matrix, and a synthesizer. Through the gating and frequency division processing of multiple microwave signals, flexible combination ablation between high-frequency and low-frequency bands can be achieved, supporting arbitrary frequency, power, and pulse combinations of single-band, dual-band, and multi-band ablation.
It enables more flexible frequency band combination ablation, supports multi-dimensional ablation parameter adjustment, improves the flexibility and adaptability of ablation, and is suitable for the treatment of different tumor tissues.
Smart Images
Figure CN121891118A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microwave ablation technology, and more particularly to a microwave ablation device. Background Technology
[0002] Microwave ablation technology involves inserting a microwave ablation needle into the target tumor under imaging guidance. The polar molecules within the tumor tissue move at high speed under the influence of the microwave field, generating heat through friction. This rapidly raises the temperature of the tumor tissue, ultimately killing or essentially eliminating tumor cells in the patient's body through high-temperature ablation. Current microwave ablation equipment typically operates in a given frequency band, such as 2450MHz or 915MHz, and is built from modules of commercially available microwave power sources. It can only perform ablation at a fixed frequency, adapting to a single-frequency ablation needle. With research into dual-frequency ablation, some improved designs have emerged, such as selecting a specific frequency band through multiple channels or relying on power switches for low-frequency and high-frequency bands to control corresponding power amplifiers. However, current designs can only achieve single-frequency ablation or simple dual-frequency ablation between high and low frequencies, resulting in limited flexibility. Summary of the Invention
[0003] This invention provides a microwave ablation device to achieve more flexible combination ablation between different frequency bands.
[0004] This invention provides a microwave ablation device, comprising: an adjustable power source and a power amplifier; the adjustable power source includes a frequency source, a switching matrix, and a synthesizer; the power amplifier includes a low-frequency power amplifier, a high-frequency power amplifier, a duplexer, and a directional coupler; wherein,
[0005] The frequency source is used to output multiple raw microwave signals;
[0006] The synthesizer includes a low-frequency power synthesizer and a high-frequency power synthesizer; the switching matrix is used to select the original microwave signal to connect a preset low-frequency microwave signal in the original microwave signal to the low-frequency power synthesizer, and to connect a preset high-frequency microwave signal in the original microwave signal to the high-frequency power synthesizer.
[0007] The output of the low-frequency power combiner is connected to the low-frequency power amplifier, and the output of the high-frequency power combiner is connected to the high-frequency power amplifier; the outputs of the low-frequency power amplifier and the high-frequency power amplifier are connected to the duplexer; the output of the duplexer is connected to the directional coupler; and the output of the directional coupler is connected to the radio frequency output port.
[0008] Optionally, the frequency source includes a crystal oscillator, a plurality of coherent programmable sources, and a low-noise amplifier corresponding to each programmable source; the crystal oscillator is used to provide a common clock for each programmable source, and the output of the coherent programmable source is output as the original microwave signal after passing through the corresponding low-noise amplifier.
[0009] Optionally, the switch matrix includes multiple signal input RF switches, and low-frequency band output RF switches and high-frequency band output RF switches that correspond one-to-one with the signal input RF switches; each signal input RF switch is used to receive a corresponding original microwave signal and select to output to the corresponding low-frequency band output RF switch or high-frequency band output RF switch; the output of the low-frequency band output RF switch is connected to the low-frequency band power combiner, and the output of the high-frequency band output RF switch is connected to the high-frequency band power combiner.
[0010] Optionally, the low-frequency power amplifier includes a low-frequency power amplifier module and a low-frequency circulator. The output of the low-frequency power combiner enters the input terminal of the low-frequency circulator through the low-frequency power amplifier module, and the output terminal of the low-frequency circulator is connected to the duplexer. The high-frequency power amplifier includes a high-frequency power amplifier module and a high-frequency circulator. The output of the high-frequency power combiner enters the input terminal of the high-frequency circulator through the high-frequency power amplifier module, and the output terminal of the high-frequency circulator is connected to the duplexer.
[0011] Optionally, the low-frequency power amplifier further includes a first power detection module connected to the isolation port of the low-frequency circulator for detecting the reflected power of the low-frequency ablation antenna; the high-frequency power amplifier further includes a second power detection module connected to the isolation port of the high-frequency circulator for detecting the reflected power of the high-frequency ablation antenna; and the power amplifier further includes a third power detection module connected to the coupling end of the directional coupler for detecting the output power.
[0012] Optionally, the adjustable power source further includes a programmable attenuator corresponding one-to-one with the multiple original microwave signals, and the original microwave signals are connected to the switching matrix through the corresponding programmable attenuator; the microwave ablation device further includes a control module for adjusting the programmable attenuator according to at least one of the low-frequency reflected power, the high-frequency reflected power and the output power, so as to dynamically adjust the device's operating power.
[0013] Optionally, the control module is further configured to calculate the voltage standing wave ratio (VSWR) of the RF output port based on the low-frequency band reflected power, the high-frequency band reflected power, and the output power, and to control the power output to stop and / or prompt fault information when the VSWR exceeds a preset threshold.
[0014] Optionally, the control module is also used to control the output waveform of the frequency source and the gating of the switching matrix.
[0015] Optionally, the microwave ablation device is used to perform conventional single-band ablation in the high-frequency or low-frequency band, and also to perform arbitrary frequency, power, or pulse combinations in the single-band or coherent dual-band.
[0016] Optionally, the preset low-frequency microwave signal includes 915MHz and 434MHz signals, and the preset high-frequency microwave signal includes 2450MHz and 5.8GHz signals.
[0017] This invention provides a microwave ablation device, including an adjustable power source and a power amplifier. The adjustable power source further includes a frequency source, a switching matrix, and a combiner. The combiner includes a low-frequency power combiner and a high-frequency power combiner. The power amplifier includes a low-frequency power amplifier, a high-frequency power amplifier, a duplexer, and a directional coupler. The frequency source can output multiple raw microwave signals. The switching matrix can select the raw microwave signals to input a preset low-frequency microwave signal into the low-frequency power combiner and a preset high-frequency microwave signal into the high-frequency power combiner. The output of the low-frequency power combiner is then connected to the low-frequency power amplifier for power amplification, and the output of the high-frequency power combiner is also connected to the high-frequency power amplifier for power amplification. The outputs of both the low-frequency and high-frequency power amplifiers are simultaneously connected to the duplexer. The output of the duplexer is connected to the directional coupler, and finally, the output of the directional coupler is connected to the radio frequency (RF) output port. The RF output port can be connected to an ablation needle via a coaxial cable. By selecting multiple microwave signals and dividing them into low-frequency and high-frequency bands for separate processing, combined ablation between different frequency bands can be achieved more flexibly. For example, ablation can be performed using time as the main axis and combining frequency, power, and pulse. At the same time, it can also achieve the usual single-frequency band ablation. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the microwave ablation device provided in an embodiment of the present invention;
[0019] Figure 2 This is a schematic diagram of another microwave ablation device provided in an embodiment of the present invention;
[0020] Figure 3 An exemplary frequency source circuit diagram provided for embodiments of the present invention;
[0021] Figure 4 An exemplary switch matrix and synthesizer circuit diagram provided for embodiments of the present invention. Detailed Implementation
[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.
[0023] Furthermore, the terms "first," "second," etc., may be used herein to describe various directions, actions, steps, or elements, but these directions, actions, steps, or elements are not limited by these terms. These terms are only used to distinguish a first direction, action, step, or element from another direction, action, step, or element. For example, without departing from the scope of the embodiments of the present invention, a first power detection module may be referred to as a second power detection module, and similarly, a second power detection module may be referred to as a first power detection module. Both the first power detection module and the second power detection module are power detection modules, but they are not the same power detection module. The terms "first," "second," etc., should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0024] Figure 1 This is a schematic diagram of the microwave ablation device provided in an embodiment of the present invention. This embodiment is applicable to conventional single-band ablation, single-band multi-frequency point combination ablation, and multi-band multi-frequency point combination ablation. Figure 1As shown, the device includes: an adjustable power source 100 and a power amplifier 200; the adjustable power source 100 includes a frequency source 101, a switching matrix 103, and a synthesizer 104; the power amplifier 200 includes a low-frequency power amplifier 201, a high-frequency power amplifier 202, a duplexer 203, and a directional coupler 204; wherein, the frequency source 101 is used to output multiple raw microwave signals; the synthesizer 104 includes a low-frequency power synthesizer 1041 and a high-frequency power synthesizer 1042; the switching matrix 103 is used to select the raw microwave signals to select a preset low-frequency microwave signal from the raw microwave signals. The signal is connected to the low-frequency power combiner 1041, and the preset high-frequency microwave signal in the original microwave signal is connected to the high-frequency power combiner 1042; the output of the low-frequency power combiner 1041 is connected to the low-frequency power amplifier 201, and the output of the high-frequency power combiner 1042 is connected to the high-frequency power amplifier 202; the outputs of the low-frequency power amplifier 201 and the high-frequency power amplifier 202 are connected to the duplexer 203; the output of the duplexer 203 is connected to the directional coupler 204; and the output of the directional coupler 204 is connected to the radio frequency output port 205.
[0025] Specifically, the multiple raw microwave signals output by the frequency source 101 can include single-band microwave signals (such as 2400MHz and 2500MHz), multi-band microwave signals (such as 2500MHz and 915MHz), or various combinations of single-band and multi-band signals. The raw microwave signals can be selected via a switch matrix 103. Specifically, by controlling the channel selection of each RF switch in the switch matrix 103, a specified preset low-frequency microwave signal can be output to a low-frequency power combiner 1041, and a specified preset high-frequency microwave signal can be output to a high-frequency power combiner 1042. The low-frequency power combiner 1041 and the high-frequency power combiner 1042 can respectively combine their respective input multiple signals. Optionally, the preset low-frequency microwave signal includes 915MHz and 434MHz signals, and the preset high-frequency microwave signal includes 2450MHz and 5.8GHz signals. Of course, by selecting the switch matrix 103, no signal can enter the low-frequency power combiner 1041 or the high-frequency power combiner 1042, or only a single signal can enter either the low-frequency power combiner 1041 or the high-frequency power combiner 1042, and so on. Furthermore, the frequency source 101 can be a programmable source, allowing the output of a specified operating frequency band by setting parameters, and also controlling which channel to not output. In particular, the frequency source 101 can also be used to output a single raw microwave signal, thereby enabling typical single-band ablation.
[0026] The output of the low-frequency power combiner 1041 can be input to the low-frequency power amplifier 201 for power amplification, and the output of the high-frequency power combiner 1042 can be input to the high-frequency power amplifier 202 for power amplification to obtain a signal that meets the operational requirements. The duplexer 203 can process the signals output from the low-frequency power amplifier 201 and the high-frequency power amplifier 202 to adapt for dual-band ablation. When only a preset low-frequency microwave signal is available, the high-frequency power amplifier 202 can be controlled to standby mode; when only a preset high-frequency microwave signal is available, the low-frequency power amplifier 201 can be controlled to standby mode. Accordingly, the duplexer 203 can be a high-power duplexer with an isolation greater than a given value, such as 75dB, between the two input ports to reduce mutual interference between the high-frequency and low-frequency power amplifiers. Furthermore, the output of the duplexer 203 can be output to the RF output port 205 via the directional coupler 204, and the RF output port 205 can be connected to the ablation needle via a coaxial cable.
[0027] In an optional implementation, the frequency source 101 includes a crystal oscillator, a plurality of coherent programmable sources, and low-noise amplifiers corresponding to each programmable source; the crystal oscillator provides a common clock for each programmable source, and the output of each coherent programmable source is output as the original microwave signal after passing through the corresponding low-noise amplifier. For example, as... Figure 2 As shown, frequency source 101 includes a crystal oscillator, two coherent programmable sources (programmable source 1 and programmable source 2), and two matched low-noise amplifiers (low-noise amplifier 1 and low-noise amplifier 2). The output of the crystal oscillator can be used as the clock for the two programmable sources, so that the programmable sources can output two phase-coherent signals, which are then input into the corresponding low-noise amplifiers to finally output two coherent raw microwave signals. Multiple programmable sources and multiple low-noise amplifiers can be identical. The programmable sources can include phase-locked loops (PLLs) and voltage-controlled oscillators (VCOs), and different parameters can be set to output frequencies corresponding to the operating frequency band.
[0028] In an optional embodiment, the switch matrix 103 includes a plurality of signal input RF switches, and low-frequency band output RF switches and high-frequency band output RF switches corresponding one-to-one with the signal input RF switches; each signal input RF switch is used to receive a corresponding original microwave signal and select to output to the corresponding low-frequency band output RF switch or high-frequency band output RF switch; the output of the low-frequency band output RF switch is connected to the low-frequency band power combiner 1041, and the output of the high-frequency band output RF switch is connected to the high-frequency band power combiner 1042.
[0029] Specifically, each signal input RF switch can correspond one-to-one with the original microwave signal, and can selectively output the input original microwave signal to the low-frequency power combiner 1041 via the corresponding low-frequency output RF switch, or to the high-frequency power combiner 1042 via the high-frequency output RF switch. The RF switches can be identical and can be selected by an enable signal. For example,... Figure 2 As shown, the switch matrix 103 includes two signal input RF switches (RF switch 1 and RF switch 2), two low-frequency output RF switches (RF switch 3 and RF switch 4), and two high-frequency output RF switches (RF switch 5 and RF switch 6). One output RF-L1 of RF switch 1 is connected to the input of RF switch 3, and the other output RF-H1 is connected to the input of RF switch 5. One output RF-L2 of RF switch 2 is connected to the input of RF switch 4, and the other output RF-H2 is connected to the input of RF switch 6. The output RF-L1A of RF switch 3 is connected to one input terminal of the low-frequency power combiner 1041, the output RF-L2A of RF switch 4 is connected to the other input terminal of the low-frequency power combiner 1041, the output RF-H1A of RF switch 5 is connected to one input terminal of the high-frequency power combiner 1042, and the output RF-H2A of RF switch 6 is connected to the other input terminal of the high-frequency power combiner 1042. Low-frequency and high-frequency output RF switches can be used to select whether to output the input signal. Correspondingly, a signal can be connected to a single input terminal, and unused channels can be isolated by connecting matched loads, such as... Figure 2 As shown, the other input terminal of RF switch 3 is connected to load 1, the other input terminal of RF switch 4 is connected to load 2, the other input terminal of RF switch 5 is connected to load 3, and the other input terminal of RF switch 6 is connected to load 4.
[0030] In an alternative implementation, such as Figure 2 As shown, the low-frequency power amplifier 201 includes a low-frequency power amplifier module and a low-frequency circulator. The output of the low-frequency power combiner 1041 enters the input terminal of the low-frequency circulator through the low-frequency power amplifier module, and the output terminal of the low-frequency circulator is connected to the duplexer 203. The high-frequency power amplifier 202 includes a high-frequency power amplifier module and a high-frequency circulator. The output of the high-frequency power combiner 1042 enters the input terminal of the high-frequency circulator through the high-frequency power amplifier module, and the output terminal of the high-frequency circulator is connected to the duplexer 203. The low-frequency and high-frequency power amplifier modules can be used for signal pre-amplification, signal power driving, and power amplification in their respective frequency bands. The amplified signals output by these modules are connected to the duplexer 203 through corresponding circulators, effectively achieving signal isolation.
[0031] Further optionally, the low-frequency power amplifier 201 also includes a first power detection module (such as...). Figure 2 The power detection module 1 in the high-frequency band is connected to the isolation port of the low-frequency band circulator and is used to detect the reflected power of the low-frequency band ablation antenna; the high-frequency band power amplifier 202 also includes a second power detection module (such as...). Figure 2 The power detection module 2 is connected to the isolation port of the high-frequency band circulator and is used to detect the reflected power of the high-frequency band ablation antenna; the power amplifier also includes a third power detection module (such as...). Figure 2 The power detection unit 3 is connected to the coupling end of the directional coupler 204 and is used to detect the output power. By detecting the reflected power and output power, the operating status of the equipment can be monitored in real time, so as to perform frequency adjustment and status control.
[0032] Optionally, the adjustable power source 100 further includes a programmable attenuator corresponding one-to-one with each of the multiple original microwave signals, the original microwave signals being connected to the switch matrix 103 through the corresponding programmable attenuator; the microwave ablation device further includes a control module for adjusting the programmable attenuator according to at least one of the low-frequency reflection power, the high-frequency reflection power, and the output power, to dynamically adjust the device's operating power. For example, as shown... Figure 2 As shown, attenuator 102 includes programmable attenuator 1 and programmable attenuator 2. Two coherent raw microwave signals output from frequency source 101 are respectively output to programmable attenuator 1 and programmable attenuator 2. The output signal of programmable attenuator 1 enters RF switch 1, and the output signal of programmable attenuator 2 enters RF switch 2. Multiple programmable attenuators can be identical and can be used to adjust the power of each raw microwave signal. Each programmable attenuator can be composed of a digital attenuator and an analog attenuator connected in series. The digital attenuator can be used for coarse adjustment of the attenuation, and the analog attenuator can be used for fine adjustment of the attenuation. The control module can control the digital attenuator by setting different parameters, and can also fine-tune the attenuation of the analog attenuator by setting different parameters and using them as control voltages after digital-to-analog conversion (DAC), filtering, and amplification. The control module can calculate the corresponding power value based on the power signals detected by each power detection module and adjust the programmable attenuator according to the algorithm, thereby performing closed-loop control to achieve the set output power. Furthermore, the voltage standing wave ratio (VSWR) of the RF output port 205 can be calculated based on the detected power, and the frequency can be automatically adjusted and tracked based on the change in VSWR to optimize the matching of the ablation antenna within the ablation needle.
[0033] Optionally, the control module is further configured to calculate the voltage standing wave ratio (VSWR) of the RF output port 205 based on the low-frequency reflected power, the high-frequency reflected power, and the output power, and to control the power output to stop and / or prompt fault information when the VSWR exceeds a preset threshold, so as to realize the protection function, and can alert relevant personnel through an alarm when necessary.
[0034] Based on the above technical solution, optionally, the microwave ablation device is used to realize conventional single-band ablation in high-frequency or low-frequency bands, and is also used to realize arbitrary frequency, power or pulse combination of single-band or coherent dual-band ablation, that is, it can realize multi-dimensional combination ablation with time as the main axis and frequency, power and pulse as parameters.
[0035] Optionally, the control module is also used to control the output waveform of the frequency source 101 and the gating of the switch matrix 103. Specifically, the control module can output frequencies corresponding to the operating frequency band by setting different parameters for the frequency source 101, and can also control the type of output waveform, thereby realizing continuous wave ablation, pulse wave ablation, or amplitude modulation wave ablation, etc. Simultaneously, the control module can also provide enable signals corresponding to various operating modes for each RF switch to control its gating signal.
[0036] Based on the above technical solution, optionally, the microwave ablation device further includes a power module for converting the incoming AC power into DC power of the target voltage to power the adjustable power source 100 and the power amplifier 200. Figure 2 As shown, the power supply and processor 300 may include a power supply module and the aforementioned control module. The power supply module can be connected to an external AC power source, and can convert AC to DC, and then to multiple DC outputs of different voltages to supply the frequency source 101, attenuator 102, switch matrix 103, power amplifier 200, etc.
[0037] The microwave ablation device provided in this embodiment can not only realize conventional single-band ablation in high-frequency or low-frequency bands, but also realize flexible combination of frequency, power, and pulse in single-band or coherent dual-band ablation. That is, it can realize multi-dimensional combination ablation with time as the main axis and frequency, power, and pulse as parameters.
[0038] To illustrate with a specific example, frequency source 101 can employ two dual-frequency programmable sources, model ADF4350B, which integrate a PLL and VCO to achieve the 915MHz and 2450MHz frequency bands. The two ADF4350B chips are controlled by a control module MCU to realize two programmable sources. Simultaneously, the output of an active crystal oscillator can be used as a common clock to achieve coherence of the output frequency phase. An exemplary frequency source 101 circuit is shown below. Figure 3As shown, one programmable source can output 2450 MHz as the first frequency of the main channel and 915 MHz as the second frequency of the slave channel, while the other programmable source can output 915 MHz as the first frequency of the main channel and 2450 MHz as the second frequency of the slave channel. By using two programmable sources, single-frequency or dual-frequency outputs of 915 MHz / 2450 MHz can be achieved, as well as dual-frequency outputs of 915 MHz and 2450 MHz.
[0039] The RF switches can be AS179-92, with a 49.9-ohm resistor load. The MCU control module manages the selection output of each RF switch. The low-frequency power combiner 1041 and the high-frequency power combiner 1042 can perform 915MHz and 2450MHz inter-frequency power combining respectively; for example, a PD0U03W can be used. An exemplary switch matrix 103 and combiner 104 circuit is shown below. Figure 4 As shown.
[0040] When single-band 2450MHz ablation is required, refer to Figure 2Programmable source 1 is controlled by an MCU, outputting 2450MHz to low-noise amplifier 1. Programmable source 2 is set by the MCU to enter a low-power standby state. The output of low-noise amplifier 1 passes through programmable attenuator 1 to RF switch 1. In switch matrix 103, each RF switch is controlled by the MCU. The output RF-H1 of RF switch 1 passes through RF switch 5, and the output RF-H1A of RF switch 5 enters one input terminal of high-frequency power combiner 1042. The other input terminal of high-frequency power combiner 1042 is connected to load 4 through RF switch 6. High-frequency power combiner 1042 realizes one input and another load matching, outputting to high-frequency power amplifier. In power amplifier 200, the low-frequency power amplifier 201 is set to a low-power standby state via MCU settings. The 2450MHz signal passes through a high-frequency power amplifier, and the output power enters a high-frequency circulator, then a high-power duplexer, and finally outputs to a directional coupler 204, and finally to the RF output port 205. When the low-frequency power amplifier 201 is in standby mode, the low-frequency circulator isolates and matches the corresponding port of the high-power duplexer. The coupling power of the directional coupler 204 enters power detection 3. The power signal detected by power detection 3 enters the MCU, which calculates the output power and adjusts the programmable attenuator 1 according to the algorithm, achieving the set power through closed-loop control. The output of the RF output port 205 is connected to an ablation needle via a coaxial cable. The ablation needle contains an ablation antenna, and the MCU can control the output waveform of the programmable source 1 to achieve continuous wave and pulse wave ablation. When impedance changes during ablation cause reflection, the reflected power is reflected from the output port of the high-power duplexer to the high-frequency input port, then reflected again through the output port of the circulator to the isolation port of the circulator, and finally enters power detection 2. Based on the signal from power detection 2, the MCU calculates the reflected power, and then calculates the voltage standing wave ratio (VSWR) of the RF output port 205 based on the output power and reflected power. When the VSWR exceeds a given value (e.g., 3), the power output is stopped to achieve the protection function. When a connection fault occurs in the RF output port 205 connected to the ablation needle via the RF cable, causing an open circuit or short circuit, and the VSWR exceeds a given value (e.g., 8), the device can issue an alarm and indicate the connection fault. During ablation, changes in the surrounding biological tissue cause impedance changes in the ablation needle, causing the center frequency to drift. The MCU can control the programmable source 1 to perform frequency scanning, calculate the output power, reflected power, and VSWR at the corresponding frequency point, and dynamically adjust the ablation operating frequency to track and match the frequency drift during the ablation process.
[0041] When equal-power dual-frequency ablation of 2400MHz and 2500MHz is required, programmable source 1 and programmable source 2 output 2400MHz and 2500MHz signals respectively under the control of MCU. For example, programmable source 1 outputs 2400MHz and programmable source 2 outputs 2500MHz. The 2400MHz output from programmable source 1 passes through low-noise amplifier 1, programmable attenuator 1, and RF switch 1 to enter RF switch 5. The 2500MHz output from programmable source 2 passes through low-noise amplifier 2, programmable attenuator 2, and RF switch 2 to enter RF switch 6. The output RF-H1A of RF switch 5 and the output RF-H2A of RF switch 6 enter the high-frequency power combiner 1042 for inter-frequency power combining. The combined power then enters the high-frequency power amplifier 202 of power amplifier 200. The low-frequency power amplifier 201 can be in standby mode under the control of MCU. The output of the high-frequency power amplifier passes through the high-frequency circulator to enter the high-power duplexer, then enters the directional coupler 204, and finally reaches the RF output port 205. The signals detected by power detectors 3 and 2 can be used by the MCU to calculate the output power, reflected power, and voltage standing wave ratio corresponding to 2400MHz and 2500MHz respectively using a time-division multiplexing method. The attenuator 102 is then used to adjust the corresponding channels to ensure that the two output powers are equal and meet the set power parameters. The MCU controls the frequency source 101, and the two output frequency points are coherent. It can also achieve combined outputs of dual-frequency, continuous wave, and pulse wave, thereby enabling multi-parameter combined ablation in conjunction with the dual-frequency ablation needle.
[0042] When dual-frequency ablation at different power levels of 2450MHz and 915MHz is required, programmable source 1 and programmable source 2, under the control of the MCU, output 2450MHz and 915MHz signals respectively. For example, programmable source 1 outputs 2450MHz, and programmable source 2 outputs 915MHz. The 2450MHz output from programmable source 1 passes through low-noise amplifier 1, programmable attenuator 1, and RF switch 1 before entering RF switch 5. The 915MHz output from programmable source 2 passes through low-noise amplifier 2, programmable attenuator 2, and RF switch 2 before entering RF switch 4. The output RF-H1A of RF switch 5 enters high-frequency power combiner 1042. The other input of high-frequency power combiner 1042 is connected to load 4 through RF switch 6. High-frequency power combiner 1042 achieves one input and another load matching, outputting to the high-frequency power amplifier 202. The output RF-L2A of RF switch 4 enters the low-frequency power combiner 1041. The other input of the low-frequency power combiner 1041 is connected to load 1 via RF switch 3. The low-frequency power combiner 1041 provides one input and load matching for the other, outputting to the low-frequency power amplifier 201. The output of the high-frequency power amplifier enters one input of the high-power duplexer via a high-frequency circulator, and the output of the low-frequency power amplifier enters the other input of the high-power duplexer via the low-frequency circulator. One output port of the high-power duplexer outputs power at two different frequency bands, which then pass through directional coupler 204 to the RF output port 205. The signals detected by power detectors 3, 2, and 1 are used by the MCU to calculate the output power, reflected power, and voltage standing wave ratio corresponding to 2450MHz and 915MHz respectively using a time-division multiplexing method. The attenuator 102 adjusts the corresponding channels to ensure that the two output powers meet the preset power, achieving dynamic frequency adjustment for each frequency band to track and match frequency drift during the ablation process. The MCU controls the frequency source 101, which can realize various combined outputs such as dual-frequency continuous wave, dual-frequency pulse wave output simultaneously, and dual-frequency pulse wave output with different powers in time division. It can also be used with dual-frequency ablation antennas of 2450MHz and 915MHz for ablation.
[0043] The microwave ablation device provided in this embodiment of the invention includes an adjustable power source and a power amplifier. The adjustable power source further includes a frequency source, a switching matrix, and a combiner. The combiner includes a low-frequency power combiner and a high-frequency power combiner. The power amplifier includes a low-frequency power amplifier, a high-frequency power amplifier, a duplexer, and a directional coupler. The frequency source can output multiple raw microwave signals. The switching matrix can select the raw microwave signals to input a preset low-frequency microwave signal into the low-frequency power combiner and a preset high-frequency microwave signal into the high-frequency power combiner. The output of the low-frequency power combiner is then connected to the low-frequency power amplifier for power amplification, and the output of the high-frequency power combiner is also connected to the high-frequency power amplifier for power amplification. The outputs of both the low-frequency and high-frequency power amplifiers are simultaneously connected to the duplexer. The output of the duplexer is connected to the directional coupler, and finally, the output of the directional coupler is connected to the radio frequency output port. The radio frequency output port can be connected to the ablation needle via a coaxial cable. By selecting multiple microwave signals and dividing them into low-frequency and high-frequency bands for separate processing, combined ablation between different frequency bands can be achieved more flexibly. For example, ablation can be performed using time as the main axis and combining frequency, power, and pulse. At the same time, it can also achieve the usual single-frequency band ablation.
[0044] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.
Claims
1. A microwave ablation device, characterized in that, include: An adjustable power source and a power amplifier; the adjustable power source includes a frequency source, a switching matrix, and a synthesizer; the power amplifier includes a low-frequency power amplifier, a high-frequency power amplifier, a duplexer, and a directional coupler; wherein... The frequency source is used to output multiple raw microwave signals; The synthesizer includes a low-frequency power synthesizer and a high-frequency power synthesizer; the switching matrix is used to select the original microwave signal to connect a preset low-frequency microwave signal in the original microwave signal to the low-frequency power synthesizer, and to connect a preset high-frequency microwave signal in the original microwave signal to the high-frequency power synthesizer. The output of the low-frequency power combiner is connected to the low-frequency power amplifier, and the output of the high-frequency power combiner is connected to the high-frequency power amplifier; the outputs of the low-frequency power amplifier and the high-frequency power amplifier are connected to the duplexer; the output of the duplexer is connected to the directional coupler; and the output of the directional coupler is connected to the radio frequency output port.
2. The microwave ablation device according to claim 1, characterized in that, The frequency source includes a crystal oscillator, multiple coherent programmable sources, and low-noise amplifiers corresponding to each programmable source; the crystal oscillator is used to provide a common clock for each programmable source, and the output of the coherent programmable source is output as the original microwave signal after passing through the corresponding low-noise amplifier.
3. The microwave ablation device according to claim 1, characterized in that, The switch matrix includes multiple signal input RF switches, and low-frequency output RF switches and high-frequency output RF switches that correspond one-to-one with the signal input RF switches; each of the signal input RF switches is used to receive a corresponding original microwave signal and select to output to the corresponding low-frequency output RF switch or high-frequency output RF switch. The output of the low-frequency output RF switch is connected to the low-frequency power combiner, and the output of the high-frequency output RF switch is connected to the high-frequency power combiner.
4. The microwave ablation device according to claim 1, characterized in that, The low-frequency power amplifier includes a low-frequency power amplifier module and a low-frequency circulator. The output of the low-frequency power combiner enters the input terminal of the low-frequency circulator through the low-frequency power amplifier module, and the output terminal of the low-frequency circulator is connected to the duplexer. The high-frequency power amplifier includes a high-frequency power amplifier module and a high-frequency circulator. The output of the high-frequency power combiner enters the input terminal of the high-frequency circulator through the high-frequency power amplifier module, and the output terminal of the high-frequency circulator is connected to the duplexer.
5. The microwave ablation device according to claim 4, characterized in that, The low-frequency power amplifier further includes a first power detection module connected to the isolation port of the low-frequency circulator for detecting the reflected power of the low-frequency ablation antenna; the high-frequency power amplifier further includes a second power detection module connected to the isolation port of the high-frequency circulator for detecting the reflected power of the high-frequency ablation antenna; the power amplifier further includes a third power detection module connected to the coupling end of the directional coupler for detecting the output power.
6. The microwave ablation device according to claim 5, characterized in that, The adjustable power source also includes a programmable attenuator corresponding to each of the multiple original microwave signals. The original microwave signals are connected to the switching matrix through the corresponding programmable attenuator. The microwave ablation device also includes a control module for adjusting the programmable attenuator according to at least one of the low-frequency reflection power, the high-frequency reflection power, and the output power to dynamically adjust the device's operating power.
7. The microwave ablation device according to claim 6, characterized in that, The control module is also used to calculate the voltage standing wave ratio (VSWR) of the radio frequency output port based on the low-frequency band reflected power, the high-frequency band reflected power, and the output power, and to control the power output to stop and / or prompt fault information when the VSWR exceeds a preset threshold.
8. The microwave ablation device according to claim 6, characterized in that, The control module is also used to control the output waveform of the frequency source and the selection of the switching matrix.
9. The microwave ablation device according to claim 1, characterized in that, The microwave ablation device is used to perform conventional single-band ablation in high-frequency or low-frequency bands, and also to perform arbitrary frequency, power, or pulse combinations in single-band or coherent dual-band ablation.
10. The microwave ablation device according to claim 1, characterized in that, The preset low-frequency microwave signal includes 915MHz and 434MHz frequency band signals, and the preset high-frequency microwave signal includes 2450MHz and 5.8GHz frequency band signals.