Medical device based on microwave plasma

Abstract

The invention provides a medical device based on microwave plasma. The medical device comprises a microwave generation source, an air inlet system, a plasma generation system and a control system. The output end of the microwave generation source is connected with the plasma generation system through a coaxial cable and is used for providing and transmitting microwave energy; according to the plasma generation system, a composite structure of coaxial arrangement of the inner electrode and the outer electrode and the spiral tungsten filament resonance coil is adopted, the quartz tube is embedded in the detachable nose assembly, and the cooperation of the coaxial electrode and the resonance coil can strengthen the local electric field intensity, accelerate the inert gas ionization speed and improve the plasma generation efficiency; and due to the detachable design of the nose component, not only is the fast replacement of consumables such as a quartz tube and a resonance coil facilitated, but also the precise coaxial alignment of the replaced component and an electrode can be ensured, and the convenience of medical operation and the stability of plasma output are both considered.

Description

TECHNICAL FIELD

[0001] The present application relates to a microwave plasma-based medical device, belonging to the technical field of plasma. BACKGROUND

[0002] There are various ways to generate atmospheric pressure inert gas microwave plasma, but there are still certain limitations in terms of startup speed, energy control accuracy, and human body applicability. In particular, in medical beauty and skin treatment applications, existing devices often cannot simultaneously achieve fast plasma excitation and precise pulse energy control, resulting in low processing efficiency or potential safety risks.

[0003] In microwave applications, energy is generated by a microwave source and fed into the load (such as heated materials or plasma chambers) through a transmission line. The core of system efficiency is to achieve impedance matching between the microwave source and the load. When the impedance is matched, the energy can be maximally absorbed by the load, and the reflected power is minimized. However, in practical applications, the impedance characteristics of the load are a highly dynamic parameter. For example, in microwave heating, the dielectric constant of the material will change significantly with temperature, humidity, and form (such as from solid to liquid); in microwave plasma applications, changes in gas pressure, gas type, and plasma density after generation will all cause fluctuations in load impedance. Therefore, the existing technology lacks an efficient solution that can quickly, continuously, and automatically track load changes, so that the microwave source always works at the optimal frequency point, thereby ensuring maximum power transmission and system safety throughout the entire process. Therefore, a microwave plasma-based medical device is proposed. SUMMARY

[0004] Therefore, the present application provides a microwave plasma-based medical device to solve or alleviate the technical problems in the prior art, at least providing a beneficial choice.

[0005] The technical solution of the present application is as follows: a microwave plasma-based medical device, comprising a microwave generation source, an air inlet system, a plasma generation system, and a control system; The output end of the microwave generation source is connected to the plasma generation system through a coaxial cable for providing and transmitting microwave energy; The output end of the air inlet system is communicated with the plasma generation system through an air pipe for delivering gas; The control system is electrically connected to the microwave generation source and the air inlet system respectively for regulating microwave energy parameters and gas delivery parameters, and realizing maximum power tracking; The plasma generating system is a handheld structure, comprising a handle shell, an inner electrode, an outer electrode, a quartz tube and a resonant coil; a connecting piece is fixedly connected in the handle shell, a cavity is arranged in the connecting piece, the inner electrode is in a needle electrode structure and arranged in the cavity, and the outer electrode is in a barrel structure and coaxially sleeved on the connecting piece; the quartz tube is located between the inner electrode and the outer electrode, and the inside of the quartz tube is communicated with the air inlet system through the air pipe; the resonant coil is a spiral tungsten coil, which is wound on the inner surface of the quartz tube and adjacent to the distal end of the inner electrode; the handle shell is provided with a detachable nose assembly, and the nose assembly is provided with a through hole for plasma ejection.

[0006] Further preferably, the air inlet system comprises at least two gas storage bottles, a gas valve and an air pipe; the gas storage bottle is a stainless steel gas tank for storing inert gas or reactive gas; the gas valve is a copper single-pole pressure regulator arranged between the gas storage bottle and the air pipe, and is electrically connected with the control system to adjust the gas delivery pressure.

[0007] Further preferably, the connecting piece is provided with a gas hole communicated with the cavity, and the air pipe delivers gas into the cavity through the gas hole, so that the gas enters the area between the quartz tube and the inner electrode and the outer electrode.

[0008] Further preferably, the quartz tube is embedded in the nose assembly, and the nose assembly and the handle shell are detachably connected by threads or a buckle structure; after connection, the resonant coil in the quartz tube is coaxially aligned with the inner electrode and the outer electrode.

[0009] Further preferably, the control system takes the upper computer as the control core, and further comprises a power detection module and a frequency generation module; wherein the power detection module and the microwave source and the upper computer are electrically connected respectively, for real-time acquisition of forward output power and reflected power data of the microwave source and transmission to the upper computer, and the upper computer cooperates with the frequency generation module to execute maximum power tracking control.

[0010] Further preferably, the upper computer cooperates with the power detection module and the frequency generation module to realize maximum power tracking control, specifically including the following steps: Step one, initial frequency scanning stage, the upper computer instructs the frequency generation module to perform full-band scanning in the preset frequency band [2.4GHz, 2.5GHz] with a step of 30ns, the power detection module synchronously acquires the forward output power and reflected power data corresponding to each scanning frequency point, the upper computer compares the acquired power data one by one through the built-in comparison algorithm, selects the frequency point with the maximum forward output power and the minimum reflected power as the initial working frequency, and controls the microwave source to start at the initial working frequency; Step two, real-time tracking adjustment phase, the host computer adopts disturbance observation method to perform closed-loop dynamic adjustment, in each control period k, first record the current working frequency f (k) and the corresponding output power P (k);Then send the disturbance instruction to the frequency generation module, make the next period working frequency adjust to f (k+1)=f (k)±Δf, Δf is the preset frequency disturbance step;After the system stabilizes, the power detection module collects the output power P (k+1) under the new frequency, the host computer calculates the power change ΔP=P (k+1)-P (k);If ΔP>0, it is determined that the current disturbance direction can improve the power transmission efficiency, and the next period maintains the original direction to continue disturbance;If ΔP<0, it is determined that the disturbance direction deviates from the optimal resonance point, and the next period applies disturbance in the opposite direction; Step three, through the above iterative cycle, the working frequency continuously converges and stabilizes near the optimal resonance point, realizing the maximum power continuous transmission under the dynamic change of load impedance.

[0011] Further preferably, the host computer drives the microwave generating source in pulse mode, the pulse repetition frequency is 1Hz-30Hz and supports single pulse mode;At the same time, the gas valve is controlled to synchronize the supply of gas and microwave energy to the plasma generating system.

[0012] Further preferably, it also includes a floor type shell;The microwave generating source, the air inlet system and the control system are integrated in the shell;The shell is provided with a user interface and a storage box, the user interface is electrically connected with the host computer to realize parameter setting and mode selection, and the storage box is used for placing small operating instruments.

[0013] Further preferably, the microwave generating source is a solid-state microwave source, the working frequency is 2.45GHz±50MHz, and the internal impedance is 50 ohms, which is matched with the coaxial cable with characteristic impedance of 50 ohms to reduce the loss in the process of microwave energy transmission.

[0014] Further preferably, it also includes a wire tube;One end of the wire tube is connected with the output port of the shell, the other end is connected with the access port of the handle shell, the coaxial cable and the air pipe are arranged in the wire tube, which is used for integrating and restraining the coaxial cable and the air pipe, realizing the synchronous wiring of the two and protecting them from external damage.

[0015] The embodiment of the application has the following advantages due to the use of the above technical scheme: ​One, the two-stage maximum power tracking control strategy of the application can dynamically adapt to the change of load impedance, realize efficient transmission of microwave energy, accurately lock the optimal initial working frequency through full-band scanning in the initial stage, continuously fine-tune the frequency through closed-loop iteration in the real-time stage, effectively solve the impedance mismatch problem caused by gas parameters and temperature fluctuations of traditional equipment, improve the utilization rate of microwave power, avoid the damage of reflected power to the microwave source, and significantly enhance the stability and reliability of the device.

[0016] Two, the plasma generation system of the application adopts a composite structure of coaxial arrangement of inner and outer electrodes and a spiral tungsten coil, and embeds the quartz tube in the detachable nose assembly. The cooperation of the coaxial electrode and the resonant coil can strengthen the local electric field strength, accelerate the ionization speed of inert gas, and improve the plasma generation efficiency. The detachable design of the nose assembly not only facilitates the quick replacement of consumables such as the quartz tube and the resonant coil, but also ensures the accurate coaxial alignment of the replaced components and the electrode, and takes into account the convenience of medical operation and the stability of plasma output.

[0017] The above summary is only for the purpose of the description and is not intended to limit in any way. In addition to the above-described illustrative aspects, embodiments and features, further aspects, embodiments and features of the application will be apparent from the drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0018] Figure 1 The structural diagram of the application.

[0019] Figure 2 The structural diagram of the gas valve and the gas cylinder in the application.

[0020] Figure 3 The structural diagram of the inner electrode and the outer electrode in the application.

[0021] Figure 4 The flow chart of the control system of the application.

[0022] Figure 5 The working flow chart of the host computer of the application.

[0023] Figure 6 The flow chart of the maximum power tracking control method of the application.

[0024] wherein: 1 - housing; 10 - microwave generating source; 11 - gas cylinder; 12 - gas valve; 13 - storage box; 14 - user interface; 15 - conduit; 16 - gas pipe; 20 - handle housing; 21 - nose assembly; 22 - quartz tube; 23 - resonant coil; 24 - through hole; 25 - connector; 26 - cavity; 27 - gas hole; 28 - inner electrode; 29 - outer electrode; 201 - coaxial cable. DETAILED DESCRIPTION In order to make the objects, technical solutions and advantages of the present application clearer, the following further describes the present application with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the scope of the present application. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0025] In the description of the present application, it should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0026] In the description of the present application, it should be noted that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, "a plurality of" means two or more, unless otherwise explicitly and specifically limited. The meaning of "several" is one or more, unless otherwise explicitly and specifically limited.

[0027] In the description of the present application, it is also necessary to explain that, unless otherwise explicitly specified and limited, the terms "arrange", "mount", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] As shown in Figures 1-6 The embodiment of the present application provides a microwave plasma-based medical device, which comprises a microwave generating source 10, an air inlet system, a plasma generating system and a control system. In one embodiment, the output end of the microwave generating source 10 is connected with the plasma generating system through a coaxial cable 201 for providing and transmitting microwave energy; the output end of the air inlet system is communicated with the plasma generating system through an air pipe 16 for conveying gas; the control system is electrically connected with the microwave generating source 10 and the air inlet system respectively for regulating and controlling microwave energy parameters and gas conveying parameters, and realizing maximum power tracking. The microwave energy generated by the microwave generating source 10 is transmitted to the plasma generating system through the coaxial cable 201 with matched characteristics to provide energy basis for gas ionization; the air inlet system conveys the gas to be ionized to the plasma generating system to build material conditions for plasma generation; the control system as a core scheduling unit collects the power state of the microwave generating source 10 and the gas parameters of the air inlet system in real time, realizes the coordinated matching of microwave energy and gas supply through parameter regulation, and simultaneously optimizes the energy transmission efficiency through the maximum power tracking algorithm.

[0029] In one embodiment, the plasma generating system is a handheld structure, which comprises a handle shell 20, an inner electrode 28, an outer electrode 29, a quartz tube 22 and a resonance coil 23; the handle shell 20 is fixedly connected with a connecting piece 25, the connecting piece 25 is provided with a cavity 26, the inner electrode 28 is in a needle pole structure and arranged in the cavity 26, and the outer electrode 29 is in a barrel structure and coaxially sleeved on the connecting piece 25; the quartz tube 22 is located between the inner electrode 28 and the outer electrode 29, and the inside of the quartz tube 22 is communicated with the air inlet system through the air pipe 16; the resonance coil 23 is a spiral tungsten coil, which is wound on the inner surface of the quartz tube 22 and adjacent to the distal end of the inner electrode 28; the handle shell 20 is provided with a detachable nose assembly 21, and the nose assembly 21 is provided with a through hole 24 for plasma ejection; The handheld handle shell 20 serves as an operating carrier to provide a holding fulcrum for the operator, facilitating flexible adjustment of the output direction of the plasma to adapt to different treatment sites. The inner electrode 28 adopts a needle electrode structure, and the tip thereof can generate an electric field concentration effect; the outer electrode 29 is a barrel structure and is coaxially arranged with the inner electrode 28, and the two form a radial electric field distribution, and the electric field lines radiate from the tip of the inner electrode 28 to the inner wall of the outer electrode 29. The spiral tungsten wire material resonant coil 23 is wound on the inner surface of the quartz tube 22 and is adjacent to the distal end of the inner electrode 28. When the microwave generating source 10 transmits microwave energy to the inner electrode 28 and the outer electrode 29 through the coaxial cable 201, the high-frequency alternating electromagnetic field of the microwave can cause electromagnetic resonance of the resonant coil 23; the resonant coil 23 itself forms an enhanced alternating electric field, and the electric field is superimposed with the radial electric field formed by the inner electrode 28 and the outer electrode 29 to construct a composite electric field with higher intensity and more concentrated distribution in the interior of the quartz tube 22, especially in the vicinity of the resonant coil 23; At the same time, since the inner electrode 28 and the outer electrode 29 are coaxially arranged, the inner electrode 28 adopts a needle electrode form, and the outer electrode 29 is in a barrel form. This coaxial design can form a directional radial electric field between the two, and the needle electrode structure of the inner electrode 28 can realize electric field focusing, and the outer electrode 29 can constrain the electric field in the annular space between the two, avoiding the dispersion of the electric field to other areas inside the handle, and ensuring that the electric field energy is concentrated on the area where the gas to be ionized is located; Cooperating with the electrode structure is the spiral tungsten wire material resonant coil 23, which is wound on the inner surface of the quartz tube 22 and is adjacent to the distal end of the inner electrode 28. When microwave energy is transmitted to the inner and outer electrodes, the high-frequency alternating electromagnetic field can excite the resonant coil 23 to produce electromagnetic resonance, and an enhanced alternating electric field is formed around the coil. The enhanced electric field and the radial electric field formed by the inner and outer electrodes can be in-phase superimposed to construct a composite electric field with higher intensity and more concentrated distribution in the interior of the quartz tube 22, which provides sufficient energy basis for rapid gas ionization and can rapidly ionize the gas in a short time.

[0030] The gas delivered by the gas inlet system enters the cavity 26 through the air pipe 16 and the gas hole 27 on the connecting piece 25, and then flows into the gap area between the quartz tube 22 and the inner electrode 28 and the outer electrode 29. At this time, the interior of the quartz tube 22 is in the above-mentioned strong composite electric field environment, and the electrons in the gas molecules acquire energy under the action of the high-frequency electromagnetic field, are excited to escape from the molecules or atoms, form free electrons and ions, and then induce gas ionization; with the continuous ionization process, a large number of charged particles and excited state neutral particles together constitute the plasma. The generated plasma is pushed by the internal gas flow pressure and moves to the end of the quartz tube 22, and is finally directed sprayed to the target skin site through the through hole 24 on the nose assembly 21.

[0031] In one embodiment, the gas inlet system comprises at least two gas cylinders 11, a gas valve 12 and a gas pipe 16; the gas cylinder 11 is a stainless steel gas tank for storing inert gas or reactive gas; the gas valve 12 is a copper single-pole pressure regulator arranged between the gas cylinder 11 and the gas pipe 16 and electrically connected with the control system to regulate the gas delivery pressure; the connecting piece 25 is provided with a gas hole 27 communicating with the cavity 26, and the gas pipe 16 delivers gas into the cavity 26 through the gas hole 27, so that the gas enters the area between the quartz tube 22 and the inner electrode 28 and the outer electrode 29; the quartz tube 22 is embedded in the nose assembly 21, and the nose assembly 21 is detachably connected with the handle shell 20 through threads or buckle structure; after connection, the resonant coil 23 in the quartz tube 22 is coaxially aligned with the inner electrode 28 and the outer electrode 29; The double gas cylinders 11 can supply different types of gas alone or in mixture to meet the needs of different medical scenarios for plasma characteristics; the control system adjusts the gas delivery pressure and flow rate by regulating the opening of the gas valve 12, and the gas enters the cavity 26 through the gas pipe 16 and the gas hole 27 of the connecting piece 25, and then uniformly flows into the ionization area between the quartz tube 22 and the electrodes; the nose assembly 21 is connected with the handle through threads / buckle, ensuring that the embedded quartz tube 22 and resonant coil 23 are coaxial with the inner and outer electrodes, and ensuring the symmetry of the electric field distribution.

[0032] In one embodiment, the control system takes the upper computer as the control core, and further comprises a power detection module and a frequency generation module; wherein the power detection module is electrically connected with the microwave source 10 and the upper computer respectively, for collecting the forward output power and reflected power data of the microwave source 10 in real time and transmitting them to the upper computer, and the upper computer cooperates with the frequency generation module to perform maximum power tracking control; the upper computer cooperates with the power detection module and the frequency generation module to realize maximum power tracking control, which specifically includes the following steps: Step one, initial frequency scanning stage: the upper computer instructs the frequency generation module to perform full-band scanning in the preset frequency band [2.4GHz, 2.5GHz] with a step of 30ns, and the power detection module synchronously collects the forward output power and reflected power data corresponding to each scanning frequency point; the upper computer compares the collected power data one by one through the built-in comparison algorithm, selects the frequency point with the maximum forward output power and the minimum reflected power as the initial working frequency, and controls the microwave source 10 to start at the initial working frequency; Step two, real-time tracking and adjusting stage: the upper computer uses the disturbance observation method to perform closed-loop dynamic adjustment; in each control period k, the current working frequency f(k) and the corresponding output power P(k) are recorded first; then the frequency generation module is sent a disturbance instruction to adjust the next period working frequency to f (k+1)=f (k)±Δf, Δf is a preset frequency disturbance step; after the system stabilizes, the power detection module collects the output power P (k+1) under the new frequency, and the upper computer calculates the power change ΔP=P (k+1)-P (k); if ΔP>0, it is determined that the current disturbance direction can improve the power transmission efficiency, and the next period maintains the original direction to continue the disturbance; if ΔP<0, it is determined that the disturbance direction deviates from the optimal resonance point, and the next period applies disturbance in the opposite direction. Step three, through the above iterative loop, the working frequency continuously converges and stabilizes near the optimal resonance point, realizing the maximum power continuous transmission under the dynamic change of load impedance.

[0033] In one embodiment, the upper computer drives the microwave generating source 10 in a pulse mode, the pulse repetition frequency is 1Hz-30Hz and supports single pulse mode; at the same time, the gas valve 12 is controlled to synchronize the supply of gas and microwave energy to the plasma generating system; The purpose of initial scanning is to quickly locate the optimal working frequency under the current load state when the device starts, and to lay the foundation for subsequent real-time tracking. The specific process is as follows, The preset frequency band [2.4GHz, 2.5GHz] is determined based on the working bandwidth of the solid-state device of the microwave generating source 10 and the optimal response frequency range of plasma ionization. This frequency band can ensure the power output stability of the microwave source and enable the inert gas to be ionized at a lower power. The frequency step of 30ns takes into account the scanning efficiency and accuracy. A large step size may miss the optimal frequency point, and a small step size may prolong the scanning time. The setting of 30ns can complete the full-band scanning within 10ms, meeting the rapid start-up requirement of medical operation.

[0034] Secondly, the upper computer stores the "forward power - reflected power" data pair of each scanning frequency point, and performs multi-dimensional screening through the built-in comparison algorithm. First, the "minimum reflected power" is the primary condition. The smaller the reflected power, the higher the impedance matching degree. Then, the "maximum forward power" is the secondary condition to ensure sufficient energy output based on matching. Finally, the unique initial working frequency is selected. For example, if the reflected power is 10W and the forward power is 400W at 2.42GHz, and the reflected power is 10W and the forward power is 400W at 2.45GHz, then 2.45GHz is selected as the initial working frequency, and the microwave generating source 10 is switched to this frequency by control command.

[0035] In addition, after the device starts, the impedance of the plasma load will dynamically change due to factors such as gas flow fluctuation, ionization degree change, treatment distance adjustment, etc. At this time, the closed-loop regulation needs to be realized through the disturbance observation method. The specific process is as follows, The control cycle is set to 100 ms, which can respond to impedance changes in time and avoid system oscillation caused by excessive frequent adjustment; the frequency disturbance step size Δf is set to 5-10 MHz, which can ensure that each disturbance can cause detectable power changes and will not cause plasma to extinguish due to frequency mutation.

[0036] In the kth control cycle, the host computer records the current operating frequency f(k) and the corresponding forward power P(k), and then sends a disturbance instruction to the frequency generation module to adjust the frequency to f(k+1)=f(k)+Δf or f(k)-Δf in the next cycle, and the initial disturbance direction can be randomly set.

[0037] After the frequency adjustment, wait for 20 ms to stabilize the system and ensure that the plasma load state is adapted to the new frequency, and then collect the forward power P(k+1) under the new frequency through the power detection module.

[0038] The host computer calculates the power change ΔP=P(k+1)-P(k), If ΔP>0, it means that the current disturbance direction moves the frequency closer to the optimal resonance point, and the impedance matching degree improves, so the next cycle continues to disturb in the same direction, and continues +Δf; If ΔP<0, it means that the current disturbance direction deviates from the optimal resonance point, and the impedance matching degree decreases, so the next cycle disturbs in the opposite direction, from +Δf to -Δf; Through the above iterative cycle, the operating frequency will gradually converge to the optimal resonance point in a "sawtooth" trajectory. When the absolute value of ΔP is less than 0.1 W for 3 consecutive control cycles, the host computer determines that the system has reached a stable state, and automatically reduces the disturbance step size to 1 MHz to maintain frequency stability with small adjustments, avoiding power fluctuations caused by excessive disturbance.

[0039] In one embodiment, it also includes a floor type shell 1; the microwave generating source 10, the air inlet system, and the control system are integrated in the shell 1; the shell 1 is provided with a user interface 14 and a storage box 13, the user interface 14 is electrically connected with the host computer to realize parameter setting and mode selection, and the storage box 13 is used to place small operating instruments; The integrated design simplifies the overall structure of the device, reduces external cable connections, and improves the neatness and mobility of the device; the user interface 14 realizes the visualization of human-computer interaction, and the setting of the storage box 13 can avoid instrument loss or pollution, which meets the standardized management needs of the medical scene.

[0040] In one embodiment, the microwave generating source 10 is a solid-state microwave source, the working frequency is 2.45 GHz±50 MHz, and the internal impedance is 50 ohms, which is matched with the coaxial cable 201 with a characteristic impedance of 50 ohms to reduce the loss in the process of microwave energy transmission. The solid-state microwave source has the characteristics of stable output frequency, small size and high reliability, and the 2.45 GHz±50 MHz frequency band meets the electromagnetic compatibility requirements of medical equipment; the internal impedance of the microwave generating source 10 is completely matched with the characteristic impedance of the coaxial cable 201, which can reduce the reflection of microwaves at the transmission interface and enable the microwave energy to be transmitted from the source end to the plasma generating system with minimal loss.

[0041] In one embodiment, the line tube 15 is also included; one end of the line tube 15 is connected with the output port of the shell 1, the other end is connected with the access port of the handle shell 20, the coaxial cable 201 and the air pipe 16 are arranged inside the line tube 15, which is used to integrate and constrain the coaxial cable 201 and the air pipe 16, realize synchronous wiring of the two and protect them from external damage; the integrated constraint design avoids the messy entanglement of the cable and the air pipe, and improves the operation convenience; the line tube 15 can effectively protect the internal cable and the air pipe from external extrusion, pulling or scraping damage, and prolong the service life of the components; In operation, the device is first started after setting the parameters through the user interface 14, the host computer of the control system first instructs the frequency generating module to scan in the [2.4 GHz, 2.5 GHz] frequency band, and the initial best working frequency is selected in combination with the power data collected by the power detection module to drive the microwave generating source 10 to start. The gas cylinder 11 of the gas inlet system delivers gas to the quartz tube 22 through the gas valve 12, the air pipe 16 and the gas hole 27 of the connecting piece 25, and the host computer controls the microwave generating source and the gas valve in a pulse manner at the same time. The microwave energy is transmitted to the inner electrode 28 and the outer electrode 29 of the plasma generating system through the coaxial cable 201. The radial electric field formed by the inner electrode 28 and the outer electrode 29 is superimposed with the resonant electric field of the resonant coil 23 in the quartz tube, so that the gas is ionized to generate plasma. The plasma is sprayed out through the through hole 24 of the nose assembly 21 under the action of the gas flow and acts on the target site. During operation, the control system monitors the power in real time through the power detection module, dynamically adjusts the microwave frequency by the disturbance observation method, maintains impedance matching to ensure efficient energy transmission.

[0042] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of various changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A microwave plasma-based medical device, characterized by: The microwave generating source (10), an air inlet system, a plasma generating system and a control system are included. The output end of the microwave generating source (10) is connected with the plasma generating system through a coaxial cable (201) for providing and transmitting microwave energy. The output end of the air inlet system is communicated with the plasma generating system through an air pipe (16) for conveying gas. The control system is electrically connected with the microwave generating source (10) and the air inlet system respectively for regulating microwave energy parameters and gas conveying parameters and realizing maximum power tracking. The plasma generating system is in a handheld structure and includes a handle shell (20), an inner electrode (28), an outer electrode (29), a quartz tube (22) and a resonance coil (23). The handle shell (20) is fixedly connected with a connecting piece (25) in which a cavity (26) is arranged. The inner electrode (28) is in a needle pole structure and arranged in the cavity (26). The outer electrode (29) is in a barrel structure and coaxially sleeved on the connecting piece (25). The quartz tube (22) is located between the inner electrode (28) and the outer electrode (29) and the inside of the quartz tube (22) is communicated with the air inlet system through the air pipe (16). The resonance coil (23) is a spiral tungsten coil and wound on the inner surface of the quartz tube (22) and adjacent to the distal end of the inner electrode (28). The handle shell (20) is provided with a detachable nose assembly (21) which is provided with a through hole (24) for discharging plasma.

2. A microwave plasma-based medical device according to claim 1, wherein: The air inlet system includes at least two gas storage cylinders (11), a gas valve (12) and an air pipe (16). The gas storage cylinder (11) is a stainless steel gas tank for storing inert gas or reactive gas. The gas valve (12) is a copper single-pole pressure regulator arranged between the gas storage cylinder (11) and the air pipe (16) and electrically connected with the control system for adjusting the gas conveying pressure.

3. A microwave plasma-based medical device according to claim 1, wherein: The connecting piece (25) is provided with a gas hole (27) communicated with the cavity (26). The air pipe (16) conveys gas into the cavity (26) through the gas hole (27) so that the gas enters the area between the quartz tube (22) and the inner electrode (28) and the outer electrode (29).

4. The microwave plasma-based medical device of claim 1, wherein: The quartz tube (22) is embedded in the nose assembly (21) and the nose assembly (21) is detachably connected with the handle shell (20) through a thread or a buckle structure. After connection, the resonance coil (23) in the quartz tube (22) is coaxially aligned with the inner electrode (28) and the outer electrode (29).

5. The microwave plasma-based medical device of claim 1, wherein: The control system takes an upper computer as a control core and further includes a power detection module and a frequency generation module. The power detection module is electrically connected with the microwave generating source (10) and the upper computer respectively for collecting forward output power and reflected power data of the microwave generating source (10) in real time and transmitting the data to the upper computer. The upper computer cooperates with the frequency generation module to perform maximum power tracking control.

6. A microwave plasma-based medical device according to claim 5, wherein: The host computer realizes maximum power tracking control through the power detection module and the frequency generation module, and specifically includes the following steps: Step one, initial frequency scanning stage, the host computer instructs the frequency generation module to perform full-band scanning in a preset frequency band [2.4GHz, 2.5GHz] with a step length of 30ns, the power detection module synchronously collects forward output power and reflected power data corresponding to each scanning frequency point, the host computer compares the collected power data one by one through a built-in comparison algorithm, selects the frequency point with the maximum forward output power and the minimum reflected power as the initial working frequency, and controls the microwave source (10) to start at the initial working frequency; Step two, real-time tracking adjustment stage, the host computer uses the disturbance observation method to perform closed-loop dynamic adjustment, in each control period k, the current working frequency f (k) and the corresponding output power P (k) are recorded first; then the disturbance instruction is sent to the frequency generation module, so that the working frequency of the next period is adjusted to f (k+1)=f (k)±Δf, and Δf is the preset frequency disturbance step; after the system stabilizes, the power detection module collects the output power P (k+1) under the new frequency, and the host computer calculates the power change ΔP=P (k+1)-P (k); if ΔP>0, it is determined that the current disturbance direction can improve the power transmission efficiency, and the next period continues to disturb in the original direction; if ΔP<0, it is determined that the disturbance direction deviates from the best resonance point, and the next period applies disturbance in the opposite direction. Step three, through the above iterative cycle, the working frequency continuously converges and stabilizes near the best resonance point, realizing the continuous transmission of maximum power under the dynamic change of load impedance. The host computer drives the microwave source (10) in a pulse mode, the pulse repetition frequency is 1Hz-30Hz and single pulse mode is supported; at the same time, the gas valve (12) is controlled to synchronize the supply of gas and microwave energy to the plasma generation system. It also includes a floor type shell (1); the microwave source (10), the air inlet system and the control system are integrated in the shell (1); a user interface (14) and a storage box (13) are arranged on the shell (1), the user interface (14) is electrically connected with the host computer to realize parameter setting and mode selection, and the storage box (13) is used for placing small operating instruments.

7. The microwave plasma-based medical device of claim 1, wherein: The microwave source (10) is a solid-state microwave source, the working frequency is 2.45GHz±50MHz, and the internal impedance is 50 ohms, which is matched with the coaxial cable (201) with a characteristic impedance of 50 ohms to reduce the loss in the process of microwave energy transmission.

8. The microwave plasma-based medical device of claim 1, wherein: It also includes a wire tube (15); one end of the wire tube (15) is connected with the output port of the shell (1), the other end is connected with the access port of the handle shell (20), the coaxial cable (201) and the air pipe (16) are arranged in the wire tube (15), which is used for integrating and restraining the coaxial cable (201) and the air pipe (16), realizing the synchronous wiring of the two and protecting them from external damage.

9. A microwave plasma-based medical device according to claim 8, wherein: ​ 10. The microwave plasma-based medical device of claim 1, wherein: ​

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