A multi-mode plasma surgical system with dynamic impedance control

Abstract

The application relates to the technical field of medical devices, and particularly discloses a multi-mode plasma surgical system with dynamic impedance control, which comprises a plasma knife head assembly, an impedance monitoring module, a driving mechanism and a controller. According to the tissue impedance value detected by the impedance monitoring module, the controller automatically controls the driving mechanism to drive the inner tube of the positive electrode to slide axially, synchronously adjusts the electrode extension length and the throat cross-sectional area, and correspondingly switches the coagulation, ablation or cutting mode. The application realizes intelligent adaptive switching of the surgical mode, can dynamically adjust the negative pressure suction intensity, improves the suction efficiency by utilizing the Venturi effect, and effectively reduces the risk of tissue carbonization and thermal damage.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically to a multimode plasma surgical system with dynamic impedance control. Background Technology

[0002] Existing plasma surgical systems typically include a blade assembly, an irrigation system, and a negative pressure suction system. They use high-frequency electrical energy to excite saline solution to generate plasma, enabling tissue cutting, ablation, and coagulation. A typical blade structure employs a bipolar coaxial design, with an inner tube as the positive electrode and an outer tube as the return electrode. The irrigation system delivers saline solution to the inner tube, while the negative pressure system directly aspirates air bubbles and excess fluid generated during surgery through a suction port or annular channel on the side wall of the outer tube. However, the electrode extension length and suction channel diameter of existing systems are usually fixed, making real-time adjustment impossible based on changes in tissue condition during surgery. When switching between different modes such as cutting, ablation, and coagulation is required, surgeons often need to change the blade or manually adjust equipment parameters, which is cumbersome and interrupts the surgical process. Furthermore, the cutting mode generates a large number of air bubbles, requiring rapid aspiration with high negative pressure; the coagulation mode requires low negative pressure to avoid removing blood clots. Existing fixed blade structures struggle to accommodate the varying negative pressure requirements of different modes.

[0003] Furthermore, existing plasma surgical systems generally lack real-time sensing and closed-loop control capabilities for tissue condition. Studies have shown that different tissue conditions have characteristic impedance ranges: tissue impedance in fluid-rich or bleeding conditions is 15-50Ω, normal soft tissue impedance is approximately 50-250Ω, and dried, coagulated tissue impedance is 250-900Ω. Real-time monitoring of tissue impedance can accurately determine the current tissue condition and automatically adjust the cutting head's operating parameters accordingly. However, in existing systems, surgeons can only rely on experience, making surgical outcomes highly dependent on individual experience and posing risks such as tissue carbonization and excessive thermal damage. Simultaneously, existing aspiration structures rely solely on external negative pressure sources for direct aspiration, lacking designs that utilize fluid dynamics principles to enhance aspiration efficiency. Therefore, there is an urgent need for a plasma surgical system capable of automatically adjusting the laryngeal inlet cross-sectional area and electrode extension length based on tissue impedance, achieving multi-mode adaptive switching. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the background art and provide a multimode plasma surgical system with dynamic impedance control.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A multi-mode plasma surgical system with dynamic impedance control includes a plasma blade assembly, an impedance monitoring module, a drive mechanism, and a controller. The plasma blade assembly includes a positive electrode inner tube, a loop electrode outer tube, and a Venturi suction structure. The positive electrode inner tube is coaxially slidably disposed within the loop electrode outer tube, forming a return flow channel between them. The Venturi suction structure is disposed within the return flow channel. The side wall of the loop electrode outer tube has a suction port communicating with the throat of the Venturi suction structure. The drive mechanism is drivenly connected to the positive electrode inner tube. The impedance monitoring module is electrically connected to both the positive electrode inner tube and the loop electrode outer tube. The controller is electrically connected to both the impedance monitoring module and the drive mechanism.

[0006] This invention uses an impedance monitoring module to detect tissue impedance in real time to determine tissue status. A controller automatically adjusts the extension length of the positive electrode inner tube and the annular flow cross-sectional area between it and the Venturi inlet based on impedance changes. On one hand, it can adaptively match the electrode's working state according to different surgical modes such as cutting, ablation, and coagulation, eliminating the need to change the blade or manually adjust parameters, thus avoiding interruptions to the surgical procedure, simplifying operation, and improving surgical continuity. On the other hand, it can dynamically adjust the fluid velocity and negative pressure suction intensity at the Venturi inlet, forming a high-speed jet to enhance the suction effect in cutting modes with high bubble volume. The system ensures a clear surgical field of view and appropriately reduces negative pressure in coagulation mode to avoid aspirating blood clots, thus accommodating the different negative pressure requirements of different surgical modes. At the same time, it improves aspiration efficiency by leveraging the Venturi hydrodynamic effect, eliminating the need for a high negative pressure external suction source. In addition, the system achieves real-time sensing of tissue impedance and closed-loop control of blade parameters. It can accurately match the working mode according to different tissue impedance ranges such as rich fluid, normal, and coagulation and drying, effectively reducing the risk of tissue carbonization and excessive thermal damage. It eliminates the excessive reliance on the doctor's experience for surgical results and significantly improves the accuracy, safety, and stability of surgical operations.

[0007] Preferably, the Venturi suction structure includes a conical contraction section, the throat, and a conical diffusion section connected in sequence. The large end of the conical contraction section faces the cutter head end, and the small end is connected to the throat. The large end of the conical diffusion section faces the handle end, and the small end is connected to the throat. The throat is a variable throat, and the cross-sectional area of ​​the throat changes with the axial sliding of the inner tube of the positive electrode.

[0008] This invention employs a Venturi suction structure consisting of a conical contraction section, a throat, and a conical diffusion section connected in sequence. The throat is designed as a variable throat whose cross-sectional area can be changed by sliding axially with the inner tube of the positive electrode. This utilizes the hydrodynamic characteristics of the Venturi tube itself to create local negative pressure when the fluid flows through the contraction section and the throat, effectively improving the suction efficiency of surgical bubbles and waste fluid. Stable suction can be achieved with only a low-power air source to drive the Venturi structure, without the need for an external high-power negative pressure source. By adaptively adjusting the cross-sectional area of ​​the throat by sliding axially with the inner tube of the positive electrode, the fluid flow rate and negative pressure can be dynamically changed according to the actual needs of the surgery. When a large number of bubbles are generated during cutting, the cross-sectional area of ​​the throat is reduced to increase the flow rate and enhance the negative pressure suction. In scenarios such as hemorrhage, the cross-sectional area of ​​the throat is increased to reduce the negative pressure, meeting the differentiated suction needs of different surgical modes and achieving precise adaptation between suction effect and surgical operation.

[0009] Preferably, the inner tube of the positive electrode is provided with a cross-section adjustment structure on the side wall of the throat. The cross-section adjustment structure includes a fixed base, a rotating disk, a long axis adjusting rod, a fixed cylinder, a long axis guide post, and a short axis adjusting rod. The fixed cylinder is located on the left side of the fixed base and is fixed to the throat by a support bar. The rotating disk is rotatably located on the right side of the fixed base via a bearing. The inner tube of the positive electrode passes through the rotating disk and drives the rotating disk to rotate. Long axis limiting grooves are opened on opposite sides of the fixed base. The long axis adjusting rod is located in the long axis limiting groove, and the long axis guide post is located on the upper surface of the long axis adjusting rod. The rotating disk has a long axis guide groove that cooperates with the long axis guide post. Two short axis adjusting rods are arranged opposite each other on the fixed base and are perpendicular to each other with the long axis adjusting rod. The fixed base has a short axis limiting groove at the position of the short axis adjusting rod. The short axis adjusting rod is slidably disposed in the short axis limiting groove. The upper surface of the short axis adjusting rod has a short axis guide post. The rotating disk has a short axis guide groove that cooperates with the short axis guide post. The outer sides of the long axis adjusting rod and the short axis adjusting rod are wrapped with an elastic layer. The structure is stably installed and positioned by the fixed connection between the support bar and the throat.

[0010] This invention utilizes the coordinated operation of a fixed base, a rotating disk, a long-axis adjusting rod, a short-axis adjusting rod, a guide post, and a guide groove. A short-axis limiting groove is positioned at a corresponding location on the fixed base, and the short-axis adjusting rod is slidably positioned within it. Combined with the short-axis guide post and guide groove, when the rotating disk rotates under the influence of the positive electrode inner tube, it simultaneously drives the long-axis and short-axis adjusting rods to radially move along their respective limiting grooves. This achieves synchronous adjustment of the long and short axis dimensions, thereby controlling the flexible transformation of the inner tube cross-section between circles of different diameters. This structure maintains a circular cross-section while uniformly scaling the outer diameter, causing the annular flow cross-sectional area at the throat to symmetrically contract or expand. This results in good uniformity of adjustment, a stable flow field without localized turbulence, and the ability to reduce the flow channel area to increase overall fluid velocity and Venturi suction in scenarios with large air bubbles, achieving efficient suction. Conversely, it can increase the flow channel area to reduce negative pressure intensity in scenarios such as hemostasis, avoiding excessive adsorption of tissue and blood clots. This allows for precise and stable adaptation to the varying suction strength requirements of different surgical procedures.

[0011] Preferably, the two short shaft adjusting rods are fixedly mounted on the fixed base.

[0012] This invention fixes two short-axis adjusting rods on a fixed base, allowing only the long-axis adjusting rod to move radially within the long-axis limiting groove. By changing the long-axis dimension while keeping the short-axis dimension constant, the cross-section of the positive electrode inner tube in the laryngeal region is precisely switched from circular to elliptical, forming an annular flow channel with uneven circumferential width. This creates a local high-speed jet in the narrow area of ​​the annular suture, significantly enhancing the negative pressure suction capability of the Venturi effect and improving the efficiency of gathering and suctioning surgical air bubbles. At the same time, the laryngeal cross-sectional area can be dynamically adjusted by changing the degree of ellipticity, achieving precise control of flow rate and negative pressure intensity. Compared to a uniformly scaled circular cross-section, it can create a stronger jet effect in a limited space, quickly removing air bubbles and ensuring a clear surgical field.

[0013] Preferably, the inner tube of the positive electrode has a fixing groove on the side wall of the throat portion, and a transmission mechanism is provided on the fixing groove. The transmission mechanism includes a rack on the fixing groove, a first gear meshing on the rack, a first drive shaft fixed to the middle of the first gear, a second gear fixed to the end of the first drive shaft, a third gear meshing below the second gear, a second drive shaft fixed to the middle of the third gear, a first bevel gear fixed on the second drive shaft, and a second bevel gear on the rotating disk. The first bevel gear and the second bevel gear mesh with each other, and while the inner tube of the positive electrode moves axially, the transmission mechanism is activated by the rack. The sequential meshing of the first gear, second gear, third gear, first bevel gear, and second bevel gear drives the rotating disk to rotate synchronously. This achieves efficient linkage conversion from axial linear displacement to rotational motion without the need for additional drive components. This transmission method can directly convert the electrode extension and retraction action into the adjustment power of the cross-sectional adjustment structure, realizing synchronous linkage adjustment of the electrode extension length and the laryngeal inlet cross-sectional area. This allows the electrode working state and negative pressure suction parameters to be adaptively matched when switching surgical modes. This simplifies the transmission and control structure, improves the system integration, and ensures synchronous and reliable adjustment actions with no lag in response, significantly improving the system's operational stability and surgical continuity.

[0014] Preferably, the inner tube of the positive electrode includes a tube body and a cutting head. The tube body and the cutting head have interconnected flushing channels, and the flushing channels in the cutting head gradually increase in size at the opening along the flushing direction. Both the inner wall of the inner tube of the positive electrode and the outer tube of the circuit electrode are provided with an insulating layer to prevent short circuits. This is a mature and readily available technology, and therefore will not be explained in detail in this document. This invention employs a separate positive electrode inner tube structure with a tube body and a blade head. Interconnected irrigation channels are set within the tube body and blade head. On one hand, this allows for a smaller tube diameter, providing more space for cross-sectional adjustment and throat annular gap control, facilitating flexible adjustment of the annular suture cross-sectional area to control the suction flow rate and negative pressure. On the other hand, the irrigation channel within the blade head gradually increases in size along the irrigation direction, significantly reducing the flow resistance of the irrigation medium and preventing splashing due to excessive flow rate. This ensures the irrigation fluid evenly covers the surgical wound in a gentle, diffused manner, improving irrigation effectiveness and reducing disturbance to the wound while maintaining a stable supply of the plasma working medium, thus balancing structural adjustment space with effective irrigation.

[0015] Preferably, a water-retaining cover extends from the side of the fixing base near the cutter head, and the water-retaining cover is connected to the cutter head via a telescopic tube.

[0016] The water-blocking cover extending from the fixed base near the cutter head end of this invention, together with the telescopic tube connected to the cutter head, can achieve follow-up extension and retraction during the axial extension and retraction of the inner tube of the positive electrode and the cross-section adjustment, ensuring that the structure moves flexibly and smoothly without interfering with the normal operation of the cutter head. It can also effectively prevent the entry of rinsing fluid, tissue fluid and air bubbles into the internal cross-section adjustment structure, avoiding liquid seepage that could cause the transmission components to jam, corrode or short-circuit and fail. This ensures the long-term stable and reliable operation of the cross-section adjustment structure and improves the sealing performance and service life of the overall structure.

[0017] Preferably, the impedance monitoring module includes a sampling resistor and an analog-to-digital converter. The sampling resistor is connected in series between the inner tube of the positive electrode and the outer tube of the loop electrode. The analog-to-digital converter is connected in parallel with the sampling resistor and is used to convert the voltage signal across the sampling resistor into a digital impedance signal and send it to the controller. The controller controls the driving mechanism to drive the inner tube of the positive electrode to slide axially according to the tissue impedance value collected by the impedance monitoring module, so as to adjust the cross-sectional area of ​​the larynx and switch the coagulation mode, ablation mode or cutting mode accordingly.

[0018] This invention's impedance monitoring module employs a combined structure of a sampling resistor and an analog-to-digital converter. The sampling resistor is connected in series between the inner tube of the positive electrode and the outer tube of the loop electrode, enabling direct and accurate acquisition of the voltage signal corresponding to the tissue's equivalent impedance. The analog voltage signal is converted into a digital impedance signal by the analog-to-digital converter and transmitted to the controller in real time, achieving high-precision and real-time detection of tissue impedance. The controller can quickly determine the tissue state based on different tissue impedance values ​​and automatically control the drive mechanism to adjust the axial sliding position of the inner tube of the positive electrode. By changing the electrode extension length, it adapts to the depth of action and energy output requirements of different modes such as coagulation, ablation, and cutting. Simultaneously, it synchronously adjusts the annular flow cross-sectional area between the inner tube of the positive electrode and the laryngeal opening, achieving linkage matching between suction negative pressure and flow rate. This allows for seamless switching between coagulation, ablation, and cutting modes without manual intervention or parameter adjustment, achieving automatic matching between impedance closed-loop feedback and surgical mode. This effectively avoids risks such as tissue carbonization and excessive thermal damage while ensuring optimal suction effect, significantly improving the intelligence level, operational safety, and adaptability to different surgical scenarios.

[0019] In summary, the beneficial effects of this invention are as follows: 1. This invention uses an impedance monitoring module to detect tissue impedance in real time. The controller automatically adjusts the extension length of the positive electrode inner tube and the annular cross-sectional area of ​​the laryngeal opening, which can adaptively match the cutting, ablation, and coagulation modes without the need to change the blade or manually adjust parameters, ensuring continuous and smooth surgery. At the same time, it dynamically controls the negative pressure intensity, enhancing the jet and suction effect during cutting and reducing the negative pressure to protect the blood clot during coagulation. It also improves suction efficiency by utilizing the Venturi effect and reduces dependence on high negative pressure sources. The system realizes impedance closed-loop control, which can accurately match the working mode according to different impedance ranges, reducing the risk of tissue carbonization and thermal damage, and improving the accuracy, safety and stability of surgery. 2. This invention employs a Venturi suction structure consisting of a conical contraction section, a throat, and a conical diffusion section connected in sequence. The throat is configured as a variable throat whose cross-sectional area can be changed by sliding along the axial direction of the inner tube of the positive electrode. This utilizes the fluid dynamics of the Venturi tube itself to create local negative pressure when the fluid flows through the contraction section and the throat, effectively improving the suction efficiency of surgical bubbles and waste fluid. Stable suction can be achieved by driving the Venturi structure with a low-power air source, without the need for an external high-power negative pressure source. By adaptively adjusting the cross-sectional area of ​​the throat by sliding along the axial direction of the inner tube of the positive electrode, the fluid flow rate and negative pressure can be dynamically changed according to the actual needs of the surgery. When a large number of bubbles are generated during cutting, the cross-sectional area of ​​the throat is reduced to increase the flow rate and enhance the negative pressure suction. In scenarios such as hemorrhage, the cross-sectional area of ​​the throat is increased to reduce the negative pressure, meeting the differentiated suction needs of different surgical modes and achieving precise adaptation between suction effect and surgical operation. 3. This invention utilizes the coordinated operation of a fixed base, a rotating disk, a long-axis adjusting rod, a short-axis adjusting rod, a long-axis guide post, and a guide groove. A short-axis limiting groove is set at a corresponding position on the fixed base, and the short-axis adjusting rod is slidably positioned within it. Combined with the short-axis guide post and guide groove, when the rotating disk rotates under the influence of the positive electrode inner tube, it simultaneously drives the long-axis and short-axis adjusting rods to make radial linkage displacements along their respective limiting grooves. This achieves synchronous adjustment of the long and short axis dimensions, thereby controlling the flexible transformation of the inner tube cross-section between circles of different diameters. This structure maintains a circular cross-section while uniformly scaling the outer diameter, causing the annular flow cross-sectional area at the throat to symmetrically contract or expand. It offers good uniformity of adjustment and a stable flow field without local turbulence. It can reduce the flow channel area in scenarios with large bubbles, such as cutting, to increase the overall fluid velocity and Venturi negative pressure suction for efficient aspiration. It can also increase the flow channel area in scenarios such as coagulation to reduce negative pressure intensity, avoiding excessive adsorption of tissue and blood clots. It can precisely and stably adapt to the differentiated aspiration force requirements of different surgical modes. 4. This invention fixes two short-axis adjusting rods on a fixed base, allowing only the long-axis adjusting rod to move radially within the long-axis limiting groove. By changing the long-axis dimension while keeping the short-axis dimension constant, the cross-section of the positive electrode inner tube in the laryngeal region is precisely switched from circular to elliptical, forming an annular flow channel with uneven circumferential width. This creates a local high-speed jet in the narrow area of ​​the annular suture, significantly enhancing the negative pressure suction capability of the Venturi effect and improving the efficiency of gathering and suctioning surgical air bubbles. At the same time, the laryngeal cross-sectional area can be dynamically adjusted by changing the degree of ellipticity, achieving precise control of flow rate and negative pressure intensity. Compared to a uniformly scaled circular cross-section, it can create a stronger jet effect in a limited space, quickly removing air bubbles and ensuring a clear surgical field. Attached Figure Description

[0020] Figure 1 This is an overall schematic diagram of the invention; Figure 2 This is a cross-sectional schematic diagram of the plasma cutting head assembly of the present invention; Figure 3 This is the present invention. Figure 2 An enlarged view of point A; Figure 4 This is a cross-sectional view of the rear end of the handle of the present invention; Figure 5 This is a schematic diagram of the back of the cross-section adjustment structure of the present invention; Figure 6 This is an overall schematic diagram of the cross-section adjustment structure of Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the fixing base according to Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the cross-section adjustment structure in Embodiment 2 of the present invention; Figure 9 This is a schematic diagram of the fixing base in Embodiment 2 of the present invention; Figure 10 This is a schematic diagram of the water-blocking cover of the present invention; Figure 11 This is a block diagram showing the relationship between the impedance monitoring module and the controller of this invention; Figure 12 This is a schematic diagram of the transmission mechanism of the present invention fixed on the water baffle; Figure 13 This is a three-dimensional schematic diagram of the transmission mechanism of the present invention; Figure 14 This is a front view of the transmission mechanism of the present invention; 1. Plasma blade assembly; 2. Impedance monitoring module; 3. Drive mechanism; 4. Controller; 5. Cross-section adjustment structure; 11. Positive electrode inner tube; 12. Loop electrode outer tube; 13. Venturi suction structure; 14. Return flow channel; 21. Sampling resistor; 22. Analog-to-digital converter; 51. Mounting base; 52. Rotary disk; 53. Long axis adjusting rod; 54. Fixing cylinder; 55. Long axis guide column; 56. Short axis adjusting rod; 57. Support bar; 111. Tube body; 112. Blade head; 113. Flushing channel; 114. Fixing groove; 121. Suction port; 131. Cone 132. Contraction section; 133. Variable throat; 134. Conical diffuser section; 300. Sealed waterproof box; 511. Long shaft limiting groove; 512. Short shaft limiting groove; 513. Short shaft guide post; 514. Water baffle; 515. Telescopic tube; 521. Long shaft guide groove; 522. Short shaft guide groove; 523. Rack; 530. Elastic layer; 54. Transmission mechanism; 523. Rack; 541. First gear; 542. First transmission shaft; 543. Second gear; 544. Third gear; 545. Second transmission shaft; 546. First bevel gear; 547. Second bevel gear. Detailed Implementation

[0021] The following specific embodiments are merely illustrative of the present invention and are not intended to limit the invention. Those skilled in the art can make modifications to these embodiments without contributing any inventive step after reading this specification, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] Example 1

[0024] according to Figures 1-2 and Figure 11As shown, a multi-mode plasma surgical system with dynamic impedance control includes a plasma blade assembly 1, an impedance monitoring module 2, a drive mechanism 3, and a controller 4. The plasma blade assembly 1 includes a positive electrode inner tube 11, a loop electrode outer tube 12, and a Venturi suction structure 13. The positive electrode inner tube 11 and the loop electrode outer tube 12 pass through a handle 101. The rear end side wall of the handle has an inlet for a washing channel 113. The end of the loop electrode outer tube 12 is provided with a negative pressure suction device. The positive electrode inner tube 11 is coaxially slidably disposed on the loop electrode outer tube 101. A return flow channel 14 is formed between the two, and the Venturi suction structure 13 is disposed in the return flow channel 14. The side wall of the outer tube of the loop electrode 12 is provided with a suction port 121 that communicates with the throat 132 of the Venturi suction structure 13. The suction port 121 is close to the blade head 112 for easy suction. The drive mechanism 3 is connected to the inner tube of the positive electrode 11. The impedance monitoring module 2 is electrically connected to the inner tube of the positive electrode 11 and the outer tube of the loop electrode 12 respectively. The controller 4 is electrically connected to the impedance monitoring module 2 and the drive mechanism 3.

[0025] according to Figure 4 As shown, the drive mechanism 3 is an electric push rod, which is located inside the sealed waterproof box 300.

[0026] according to Figures 2-3 As shown, the Venturi suction structure 13 includes a conical contraction section 131, a throat 132, and a conical diffusion section 133 connected in sequence. The large end of the conical contraction section 131 faces the blade end, and the small end is connected to the throat 132. The large end of the conical diffusion section 133 faces the handle end, and the small end is connected to the throat 132. The throat 132 is a variable throat, and the cross-sectional area of ​​the throat 132 changes with the axial sliding of the positive electrode inner tube 11. The positive electrode inner tube 11 includes a tube body 111 and a blade 112. The tube body 111 and the blade 112 are provided with interconnected flushing channels 113. The flushing channel 113 in the blade 112 gradually increases in size along the flushing direction. At the same time, the conical diffusion section 133 can slow down the airflow velocity, reduce flow resistance and noise, and avoid airflow turbulence affecting suction stability.

[0027] according to Figure 5 and Figures 8-10As shown, the positive electrode inner tube 11 is provided with a cross-section adjustment structure 5 on the side wall of the throat 132. The cross-section adjustment structure 5 includes a fixed base 51, a rotating disk 52, a long axis adjusting rod 53, a fixed cylinder 54, a long axis guide column 55, and a short axis adjusting rod 56. The fixed cylinder 54 is located on the left side of the fixed base 51 and is fixed to the throat 132 by a support bar 57. The rotating disk 52 is rotatably located on the right side of the fixed base 51 by a bearing. The positive electrode inner tube 11 passes through the rotating disk 52 and drives the rotating disk. The rotating disk 52 has long axis limiting grooves 511 on opposite sides of the fixed base 51. The long axis adjusting rod 53 is disposed in the long axis limiting groove 511. The long axis guide post 55 is disposed on the upper surface of the long axis adjusting rod 53. The rotating disk 52 has long axis guide grooves 521 that cooperate with the long axis guide post 55. The two short axis adjusting rods 56 are disposed opposite each other on the fixed base 51 and are perpendicular to the long axis adjusting rod 53. The outer sides of the long axis adjusting rod 53 and the short axis adjusting rod 56 are covered with an elastic layer 530. according to Figures 12-14 As shown, the inner tube 11 of the positive electrode has a fixing groove 114 on the side wall of the throat 132 portion. A transmission mechanism 54 is provided on the fixing groove 114. The transmission mechanism 54 includes a rack 523 mounted on the fixing groove 114. A first gear 541 meshes with the rack 523. A first transmission shaft 542 is fixed to the middle of the first gear 541. A second gear 543 is fixed to the end of the first transmission shaft 542. A third gear 544 meshes with the lower part of the second gear 543. A second transmission shaft 545 is fixed to the middle of the third gear 544. A first bevel gear 546 is fixed on the 545, and a second bevel gear 547 is provided on the rotating disk 52. The first bevel gear 546 and the second bevel gear 547 mesh with each other. A water baffle 514 extends from the side of the fixed base 51 near the cutter head. The first drive shaft 542 and the second drive shaft 545 are rotatably mounted on the water baffle 514. The water baffle 514 is connected to the cutter head 112 through a telescopic tube 515. The long shaft adjusting rod 53 and the short shaft adjusting rod 56 both include a slide rod 531 and an arc block 532. In the initial state, the four arc blocks 532 form a circle.

[0028] according to Figure 11As shown, the impedance monitoring module 2 includes a sampling resistor 21 and an analog-to-digital converter 22. The sampling resistor 21 is connected in series between the inner tube 11 of the positive electrode and the outer tube 12 of the loop electrode. The analog-to-digital converter 22 is connected in parallel with the sampling resistor 21 and is used to convert the voltage signal across the sampling resistor 21 into a digital impedance signal and send it to the controller 4. The controller 4 controls the driving mechanism 3 to drive the inner tube 11 of the positive electrode to slide axially according to the tissue impedance value collected by the impedance monitoring module 2, so as to adjust the cross-sectional area of ​​the throat 132 and switch the coagulation mode, ablation mode or cutting mode accordingly.

[0029] Specifically, the sampling resistor 21 is connected in series between the inner tube 11 of the positive electrode and the outer tube 12 of the loop electrode. When a high-frequency current flows through the inner tube 11 of the positive electrode, the human tissue, and the outer tube 12 of the loop electrode, a voltage signal Vs proportional to the tissue impedance is generated across the sampling resistor 21. The analog-to-digital converter 22 is connected in parallel with the sampling resistor 21, which acquires the voltage signal Vs in real time and converts it into a digital impedance value, which is then sent to the controller 4.

[0030] The controller 4 has preset impedance threshold ranges corresponding to different tissue states. For example, in the case of fluid-rich / hemorrhagic conditions, the high-frequency impedance at 100kHz is generally 15-50 ohms; 2. The high-frequency impedance of normal soft tissue is 50-250 ohms; and the high-frequency impedance of dried coagulated tissue is 250-900 ohms. After receiving the digital impedance value, the controller 4 compares it with the preset threshold to determine the current state of the tissue. Based on the determination result, the controller 4 automatically outputs corresponding control commands to the drive mechanism 3, driving the inner tube 11 of the positive electrode to slide axially to the corresponding position.

[0031] The axial sliding of the inner tube 11 of the positive electrode changes the extension length of its distal end relative to the outer tube 12 of the circuit electrode, thereby adjusting the energy density of the electrode acting on the tissue to meet the energy output requirements of different modes such as coagulation, ablation, or cutting. On the other hand, this sliding action simultaneously adjusts the cross-sectional area of ​​the larynx 132, causing corresponding changes in the fluid velocity and negative pressure flowing through the Venturi suction structure 13, thus achieving precise matching between the suction force and the surgical mode. Therefore, based on real-time impedance detection results, the system automatically and seamlessly switches between coagulation, ablation, and cutting modes and adapts parameters accordingly.

[0032] Working principle: When the system is working, the external suction device is connected to the return flow channel 14 to form a basic negative pressure passage. The physiological saline is delivered to the front end of the blade head 112 through the flushing channel 113 of the positive electrode inner tube 11. The gradually expanding flushing channel 113 in the blade head 112 allows the flushing fluid to spread gently and cover the surgical area, providing a medium for plasma excitation and cooling the wound. The impedance monitoring module 2 collects the voltage signal corresponding to the tissue impedance in real time through the sampling resistor 21 connected in series between the bipolar electrodes. After being converted into a digital impedance signal by the analog-to-digital converter 22, it is transmitted to the controller 4. The controller 4 judges the tissue state based on the impedance value and automatically switches the coagulation mode, ablation mode or cutting mode accordingly.

[0033] In coagulation mode, tissue impedance is high. Controller 4 controls drive mechanism 3 to retract the inner tube 11 of the positive electrode, reducing the electrode extension length and decreasing the depth of action and energy output intensity. Simultaneously, the rack 114 of the cross-section adjustment structure 5 drives the first gear 541 to rotate clockwise, the second gear 543 to rotate clockwise, and the third gear 544 to rotate counterclockwise, thereby driving the first bevel gear 546 to rotate counterclockwise, causing the second bevel gear 547 to rotate clockwise. This, in turn, drives the long axis guide groove 521, the short axis guide groove 522, and the corresponding long axis guide post 55 and short axis 513 to retract the long axis adjusting rod 53 and the short axis adjusting rod 56, thus retracting the cross-section adjustment structure. The size of structure 5 is reduced, thereby increasing the cross-sectional area of ​​the throat opening 132, reducing the suction negative pressure and flow rate, and avoiding the removal of blood clots or damage to coagulated tissue. In ablation mode, the tissue impedance is in the medium range. The controller 4 controls the drive mechanism 3 to drive the inner tube 11 of the positive electrode to extend appropriately, so that the electrode extension length is moderate and matches the required depth and energy for ablation. At the same time, the rack 114 of the cross-section adjustment structure 5 drives the first gear 541 to rotate counterclockwise, the second gear 543 to rotate counterclockwise, and the third gear 544 to rotate clockwise, thereby driving the first bevel gear 546 to rotate clockwise, and causing the second bevel gear 547 to rotate counterclockwise, which in turn drives the long shaft guide groove 521, The short-axis guide groove 522 and the corresponding long-axis guide post 55 and short-axis 513 drive the long-axis adjusting rod 53 and short-axis adjusting rod 56 to extend, thereby increasing the cross-sectional adjustment structure 5 and adjusting the cross-sectional area of ​​the throat 132 to a medium size, balancing suction efficiency and tissue protection. In cutting mode, the tissue impedance is low, and the controller 4 controls the drive mechanism 3 to drive the positive electrode inner tube 11 to extend to the maximum extent, extending the electrode extension length to increase the cutting depth and energy output, while reducing the cross-sectional area of ​​the throat 132. With the help of the Venturi suction structure 13, a high-speed jet and strong negative pressure are formed to quickly remove a large number of surgical air bubbles. When the two axes are linked, the uniform scaling of the circular cross-section of the inner tube is achieved. This causes the annular cross-sectional area of ​​the larynx 132 to change symmetrically; the conical contraction section 131, the larynx 132, and the conical diffusion section 133 of the Venturi suction structure 13, together with the external suction device, form a highly efficient and controllable negative pressure suction in the return flow channel 14, and discharge air bubbles and waste liquid through the suction port 121; the water baffle 514 and the telescopic tube 515 of the fixed seat 51 move synchronously with the extension and retraction of the electrode to prevent liquid from seeping into the cross-sectional adjustment structure 5. Under the impedance closed-loop control, the system realizes the adaptive linkage of the extension length of the inner tube 11 of the positive electrode, the cross-sectional area of ​​the larynx 132, the suction negative pressure, and the surgical mode, and can continuously and stably complete the coagulation, ablation, and cutting operations without manual intervention.

[0034] Example 2

[0035] The difference from Embodiment 1 above is that, according to Figures 6-7As shown, the two short-axis adjusting rods 56 are fixed on the fixed base 51, so that the cross-section of the positive electrode inner tube 11 in the throat 132 region is precisely switched from a circle to an ellipse, forming an annular flow channel with uneven circumferential width. This can form a local high-speed jet in the narrow area of ​​the annular suture, which significantly enhances the negative pressure suction capacity of the Venturi suction structure 13, improves the efficiency of gathering and suctioning surgical air bubbles, and can also dynamically adjust the cross-sectional area of ​​the throat 132 by changing the degree of ellipticity, so as to achieve fine control of flow rate and negative pressure intensity. Compared with a uniformly scaled circular cross-section, it can form a strong jet effect in a limited space, quickly remove air bubbles and ensure a clear surgical field.

Claims

1. A multimode plasma surgical system with dynamic impedance control, characterized in that, The device includes a plasma cutting head assembly (1), an impedance monitoring module (2), a drive mechanism (3), and a controller (4). The plasma cutting head assembly (1) includes a positive electrode inner tube (11), a loop electrode outer tube (12), and a Venturi suction structure (13). The positive electrode inner tube (11) is coaxially slidably disposed in the loop electrode outer tube (12), and a return flow channel (14) is formed between the two. The Venturi suction structure (13) is disposed in the return flow channel (14). The side wall of the loop electrode outer tube (12) is provided with a suction port (121) that communicates with the throat (132) of the Venturi suction structure (13). The drive mechanism (3) is connected to the positive electrode inner tube (11) in a transmission connection. The impedance monitoring module (2) is electrically connected to the positive electrode inner tube (11) and the loop electrode outer tube (12) respectively. The controller (4) is electrically connected to the impedance monitoring module (2) and the drive mechanism (3).

2. The multimode plasma surgical system with dynamic impedance control according to claim 1, characterized in that, The Venturi suction structure (13) includes a conical contraction section (131), a throat (132), and a conical diffusion section (133) connected in sequence. The large end of the conical contraction section (131) faces the tip end, and the small end is connected to the throat (132). The large end of the conical diffusion section (133) faces the handle end, and the small end is connected to the throat (132). The throat (132) is a variable throat, and the cross-sectional area of ​​the throat (132) changes with the axial sliding of the positive electrode inner tube (11).

3. A multimode plasma surgical system with dynamic impedance control according to claim 2, characterized in that, The positive electrode inner tube (11) is provided with a cross-section adjustment structure (5) on the side wall of the throat (132). The cross-section adjustment structure (5) includes a fixed seat (51), a rotating disk (52), a long axis adjusting rod (53), a fixed cylinder (54), a long axis guide column (55), and a short axis adjusting rod (56). The fixed cylinder (54) is located on the left side of the fixed seat (51) and is fixed to the throat (132) by a support bar (57). The rotating disk (52) is rotatably located on the right side of the fixed seat (51) by a bearing. The positive electrode inner tube (11) passes through the rotating disk (52) and drives it to rotate. The disk (52) rotates, and the fixed seat (51) has long shaft limiting grooves (511) on opposite sides. The long shaft adjusting rod (53) is located in the long shaft limiting groove (511). The long shaft guide post (55) is located on the upper surface of the long shaft adjusting rod (53). The rotating disk (52) has a long shaft guide groove (521) that cooperates with the long shaft guide post (55). The two short shaft adjusting rods (56) are located opposite each other on the fixed seat (51) and are perpendicular to the long shaft adjusting rod (53). The outer sides of the long shaft adjusting rod (53) and the short shaft adjusting rod (56) are covered with an elastic layer (530).

4. A multimode plasma surgical system with dynamic impedance control according to claim 3, characterized in that, The two short shaft adjusting rods (56) are fixedly mounted on the fixed base (51).

5. A multimode plasma surgical system with dynamic impedance control according to claim 3, characterized in that, The fixed base (51) is provided with a short shaft limiting groove (512) at the position of the short shaft adjusting rod (56). The short shaft adjusting rod (56) is slidably disposed in the short shaft limiting groove (512). The upper surface of the short shaft adjusting rod (56) is provided with a short shaft guide post (513). The rotating disk (52) is provided with a short shaft guide groove (522) that cooperates with the short shaft guide post (513).

6. A multimode plasma surgical system with dynamic impedance control according to claim 3, characterized in that, The inner tube (11) of the positive electrode is provided with a fixing groove (114) on the side wall of the throat (132) portion. A transmission mechanism (54) is provided on the fixing groove (114). The transmission mechanism (54) includes a rack (523) provided on the fixing groove (114). A first gear (541) is meshed on the rack (523). A first transmission shaft (542) is fixed in the middle of the first gear (541). A second gear (543) is fixed at the end of the first transmission shaft (542). A third gear (544) is meshed below the second gear (543). A second transmission shaft (545) is fixed in the middle of the third gear (544). A first bevel gear (546) is fixed on the second transmission shaft (545). A second bevel gear (547) is provided on the rotating disk (52). The first bevel gear (546) and the second bevel gear (547) mesh with each other.

7. A multimode plasma surgical system with dynamic impedance control according to claim 6, characterized in that, The positive electrode inner tube (11) includes a tube body (111) and a blade (112). The tube body (111) and the blade (112) are provided with interconnected flushing channels (113). The flushing channel (113) in the blade (112) gradually increases in size along the flushing direction.

8. A multimode plasma surgical system with dynamic impedance control according to claim 7, characterized in that, A water shield (514) extends from the side of the fixed base (51) near the cutter head, and the water shield (514) is connected to the cutter head (112) via a telescopic tube (515).

9. A multimode plasma surgical system with dynamic impedance control according to claim 1, characterized in that, The impedance monitoring module (2) includes a sampling resistor (21) and an analog-to-digital converter (22). The sampling resistor (21) is connected in series between the inner tube of the positive electrode (11) and the outer tube of the loop electrode (12). The analog-to-digital converter (22) is connected in parallel with the sampling resistor (21) to convert the voltage signal across the sampling resistor (21) into a digital impedance signal and send it to the controller (4).

10. A multimode plasma surgical system with dynamic impedance control according to claim 9, characterized in that, The controller (4) controls the drive mechanism (3) to drive the positive electrode inner tube (11) to slide axially according to the tissue impedance value collected by the impedance monitoring module (2), so as to adjust the cross-sectional area of ​​the throat (132) and switch the coagulation mode, ablation mode or cutting mode accordingly.

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