Hand-held integrated single needle jet coagulation device and safe current control method

Abstract

This invention discloses a handheld integrated single-needle jet coagulation device and a safe current control method. The device highly integrates a lithium battery, AC power module, current limiting module, and single-needle jet arc electrode unit into a handheld shell. It can be connected to different working gases and has the advantages of small size, portability, and adaptability to multiple coagulation scenarios. This invention adopts a single-needle jet arc self-selection path mechanism, which autonomously selects the discharge path with the lowest tissue impedance, solves the problem of random current diffusion in multi-electrode systems, avoids local overcurrent burns, and improves coagulation uniformity and operational safety. At the same time, a coagulation impedance-current value mapping model is established to reveal the exponential decay law of coagulation impedance and arc current, achieving accurate current characterization. A dual-threshold reverse control mechanism is proposed, which uses the human body safe current and biomedical effect dual threshold constraints to reverse derive the impedance safety window and quantify the power supply current limiting parameters, thereby improving the coagulation effect while ensuring safety.

Description

Technical Field

[0001] This invention relates to the research and application of plasma in biomedicine, and in particular to a handheld integrated single-needle jet coagulation device and a safe current control method. Background Technology

[0002] Low-temperature plasma has been used in biomedical applications for many years, such as sterilization, wound healing, and tumor treatment. It is considered a novel molecular activation method due to the large number of high-energy electrons, ions, excited-state atoms, free radicals, reactive oxygen species (ROS), reactive nitrogen species (RNS), electric fields, and ultraviolet light contained in the system. Low-temperature plasma is a non-equilibrium plasma generated by gas discharge under open atmospheric pressure. Because the electron temperature in the system is much higher than the heavy particle temperature, it can achieve high chemical activity while maintaining a near-room temperature. In trauma emergency care, surgery, and war wound treatment, uncontrolled bleeding is the leading cause of death. Traditional hemostasis techniques rely on high-temperature thermal effects, which can quickly close blood vessels, but have complications such as deep tissue carbonization, thermal damage diffusion, and postoperative adhesions. Arc discharge plasma coagulation technology, with its low-temperature characteristics and multiple biological effects, has become a novel medical hemostasis and coagulation method.

[0003] Currently, various methods are used clinically to achieve hemostasis and coagulation. Traditional hemostasis methods include physical methods, pharmacological methods, and surgical hemostasis. Although these methods play a role in wound hemostasis and coagulation, they also have many drawbacks. For example, physical compression and bandaging are simple, immediate, effective, and inexpensive, but their effectiveness in deep bleeding from large blood vessels is limited and may lead to tissue ischemia. While pharmacological intervention has targeted effects on hemostasis and coagulation, it also has significant limitations and can induce other adverse reactions such as drug allergies. Although surgical hemostasis can directly close the severed ends of blood vessels and achieve thorough hemostasis, improper operation may damage surrounding tissues.

[0004] Arc discharge plasma exhibits significant advantages in hemostasis and coagulation. By ionizing different gases to generate plasma jets, it allows for precise current control to achieve deep, controllable thermal penetration, causing instantaneous denaturation of tissue proteins and reliably closing deep blood vessels, overcoming the superficial hemostasis limitations of traditional electrocoagulation. Simultaneously, the active substances excited by the arc directly activate platelet coagulation factors, accelerating thrombus formation and improving coagulation efficiency. Through self-selection pathways, it automatically selects low-resistance pathways, forming a uniformly diffused coagulation zone with significant effects. Its core challenges are: the safe current threshold for the human body is strictly limited by international standards; and the minimum effective current must meet specific biological effects. Existing methods use static current limiting, which cannot respond to real-time changes in tissue impedance during treatment and cannot estimate specific power supply current limiting parameters, leading to the risk of current runaway. Summary of the Invention

[0005] 1. The technical problem to be solved:

[0006] Traditional electrosurgical equipment suffers from problems such as large size, fixed gas, and lack of safe current regulation.

[0007] 2. Technical Solution:

[0008] To address the above problems, the present invention provides a handheld integrated single-needle jet coagulation device, comprising a housing, an air inlet at one end of the housing, and an electrode unit at the other end. A charging module, a lithium battery, an AC power module, a current limiting module, and the electrode unit are all disposed inside the housing and connected in sequence. The air inlet and the electrode unit are connected via an internal flexible tube.

[0009] The AC power module is a load-adaptive drive power supply.

[0010] The circuit of the current limiting module shown is a variable resistor, using a power transistor MOSFET, and controls the gate and source voltage U of the MOSFET. gs The size, thereby controlling the equivalent resistance R of the drain and source. ds .

[0011] Control U gs The specific method is as follows: a resistor R is connected in series with the source of the MOSFET. control In this MOSFET, the drain (D) and source (S) are connected in series with R. control Connected to the power output port, the drive voltage U of the drive circuit dri =U gs +I acr *R control Drive control voltage U dri The discharge current I remains unchanged. acr When it gets bigger, I acr *R control This will increase, causing the gate-source voltage U applied to the MOSFET to... gs Reduce, thereby controlling the R of the MOSFET ds When the resistance increases, I is automatically switched to I. acr The current decreases.

[0012] The electrode unit described is a single-needle jet electrode structure.

[0013] The device is 217mm long and 47mm in diameter.

[0014] The present invention also provides a safe current control method for the aforementioned handheld integrated single-needle jet coagulation device, comprising the following steps:

[0015] Step S01: Establish an electrical path model for the coupling of single-needle jet current and arc impedance through experiments.

[0016] Step S02: Establish discharge current I acr With arc impedance R acr The fitting mathematical model between them yields the discharge current I under different treatment intervals h. acr With the arc impedance R of the jet plume acr The relationship between the curves.

[0017] Step S03: Using the biomedical effect current threshold and the human body safe current threshold as constraints, substitute the biomedical effect current threshold and the human body safe current threshold into the safe current range threshold model function respectively. and Two arc impedance ranges are derived from this. and Simultaneously, the intersection of the ranges of change of the two threshold impedances is taken. roll out The current-limiting resistor size is selected by the range, and the current-limiting parameters of the power supply are designed.

[0018] Step S04: Use the current-limiting resistor and power supply current-limiting parameters obtained in step S03 to perform coagulation.

[0019] The specific method of step S01 is as follows: Measure experimental data for different values ​​of h, and change the size of the sliding rheostat to change the magnitude of the jet current. Conduct the experiment using the controlled variable method: when h is fixed, change the resistance of the sliding rheostat to change the magnitude of the arc current; when the resistance of the sliding rheostat is fixed, change h and measure the changes in the current and arc impedance. By accumulating experimental data under different combinations of sliding rheostat impedance and h, analyze and derive the electrical path model of the coupling between the single-needle jet current and the arc impedance.

[0020] Different distances with h values ​​of 0mm, 2mm, 4mm, 6mm, and 8mm were measured respectively.

[0021] 3. Beneficial effects:

[0022] Compared with traditional electrosurgical devices, this invention integrates power supply and electrode modules into one unit, while being small in size, easy to carry and handheld, and supporting the replacement of various medical gases for actual needs, adapting to different coagulation scenarios.

[0023] This invention employs a single-needle jet arc self-selection path mechanism, autonomously selecting the path with the lowest tissue impedance for discharge, thus solving the problem of random current diffusion in multi-electrode structures. Compared with existing fixed electrode structures, which are prone to causing local current to exceed the safety threshold, this invention avoids local overcurrent burns, forms a uniform coagulation zone, and significantly improves coagulation uniformity and operational safety.

[0024] This invention innovatively proposes a coagulation impedance-current value mapping model (Iacr-Racr), which reveals the exponential decay law of coagulation impedance and arc current through experiments. This model enables the current to be accurately characterized by the impedance state, providing a theoretical basis for dynamic control and overcoming the defect of "blindly reducing current".

[0025] This invention proposes a dual-threshold reverse regulation mechanism, which uses the human body safe current threshold and the biomedical effect threshold as dual constraints to deduce the coagulation impedance safety window in reverse. Compared with the shortcomings of existing technologies that lack quantitative safe operation and biomedical effect window, this invention designs power supply current limiting parameters to ensure coagulation efficacy while ensuring safe operation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0027] Figure 2 This is a schematic diagram of a single-needle jet electrode structure.

[0028] Figure 3 This is a schematic diagram illustrating the principle of the coagulation pathway self-screening function.

[0029] Figure 4 This is a schematic diagram of a safety current limiting module.

[0030] Figure 5 This is a schematic diagram of the adaptive control circuit of the current limiting module.

[0031] Figure 6 This is a schematic diagram of the experimental platform.

[0032] Figure 7 The discharge current I under different processing intervals h acr With the arc impedance R of the jet plume acr The relationship between the curves.

[0033] Explanation of reference numerals in the attached diagram: 1. Power supply unit; 2. Current limiting module; 3. AC power module; 4. Lithium battery; 5. Charging module; 6. Air inlet. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] like Figure 1 As shown, a handheld integrated single-needle jet coagulation device includes a housing. One end of the housing is provided with an air inlet 6, and the other end is provided with an electrode unit 1. A charging module 5, a lithium battery 4, an AC power module 3, a current limiting module 2, and the electrode unit 1 are all disposed inside the housing and connected in sequence. The air inlet 6 is connected to the electrode unit 1 through an internal flexible tube.

[0036] The device is powered by a lithium battery, which is reusable and compact, making it portable. It discharges through a high-frequency AC power supply to treat actual tissue for hemostasis and coagulation.

[0037] The power supply, single-needle jet electrode, and other components are integrated into a small handheld device. Users only need to connect the target working gas to the airway interface of the integrated single-needle jet coagulation device, adjust the airflow rate, and press the power setting button to activate the single-needle jet for hemostasis and coagulation applications.

[0038] In one embodiment, a load-adaptive drive power supply is employed, which can support discharge drive for different inert gases. The frequency point is tested according to the coupling requirements of different working gas conditions. s_Ar f s_He The high-frequency AC output of the power supply is reduced from the minimum frequency f. s_min Gradually increase to f s_max , in the case of f s_max Gradually decrease to f s_min And there exists f s_min < f s_He <f s_Ar < f s_max Therefore, it can ensure that even under different working gas conditions of Ar and He, the coupled discharge power will be adaptively adjusted accordingly, thereby ensuring that the single needle jet discharge will not over-discharge and cause electrical safety problems in the inert gas He with a low discharge breakdown voltage. At the same time, it can take advantage of the differences in the physical properties of different discharge gases to cover a variety of clinical application scenarios.

[0039] In one embodiment, the electrode unit is a single-needle jet electrode structure, such as... Figure 2 As shown, by designing the distance d between the tip of the single needle and the tip of the glass tube, this distance needs to be controlled within the range of 0mm <= d <= 50mm. This ensures that, in coagulation applications, the single-needle plasma jet can adjust the discharge current I of the jet according to the coagulation state of the target coagulated tissue. The equivalent impedance of the coagulated blood is relatively large, while the equivalent impedance of the fresh, uncoagulated blood tissue is relatively small. acr It automatically directs more current components (i.e., plasma) through the lower impedance circuit (i.e., the fresh blood tissue portion), thus possessing an adaptive coagulation pathway self-selection function, such as... Figure 3 As shown, the plasma distribution automatically spreads to areas of fresh, uncoagulated blood tissue, resulting in more efficient coagulation treatment without requiring doctors to control the distance and position of the jet. This allows for better uniformity in the coagulation treatment of the target coagulated tissue.

[0040] A discharge breakdown electric field is formed between the needle electrode of the single-needle jet and the human body. The inert gas within this electric field discharges, generating discharge plasma that acts on the target coagulation site in the human body. Therefore, the entire discharge current I... acr In fact, all of these currents flow into the human body, forming a complete electrical pathway, and this current I... acr The size and characteristics of I directly determine its effectiveness in hemostasis and coagulation in biological applications. Therefore, it is necessary to study I... acr Strict control measures must be implemented to ensure hemostasis and coagulation function while controlling the inflow of IgA into the human body. acr The safety threshold is reliably controlled to ensure the electrical safety of the device operation.

[0041] A current-limiting module circuit is connected in series at the high-voltage output port of the power supply. This module circuit is a variable resistor, such as... Figure 4 As shown, the design method for the safe current limiting module unit parameters is based on a safe current range threshold model and a dynamic mapping model of coagulation impedance and current. It employs a reverse design approach with dual threshold constraints: the minimum current value ensures effective coagulation by achieving tissue protein denaturation and platelet activation through biomedical effects. If the current is below this threshold, coagulation efficiency will significantly decrease, failing to achieve the expected hemostatic effect. The maximum current limit is set according to international human safety current standards to avoid electric shock injury and tissue burns caused by excessive current. If the current exceeds this threshold, it may lead to safety risks such as deep tissue carbonization and thermal damage propagation.

[0042] In one embodiment, the variable resistance function of the current limiting module circuit, such as Figure 5 As shown, a power transistor MOSFET is used, and the gate and source voltages U of the MOSFET are controlled. gs The size, thereby controlling the equivalent resistance R of the drain and source. ds This fulfills the variable resistance requirement of the current limiting module. Simultaneously, it adjusts U... gs The method is to connect a resistor R in series with the source of the MOSFET. control In this MOSFET, the drain (D) and source (S) are connected in series with R. control Connect it to the power output port.

[0043] The driving voltage U of the MOSFET driving circuit can be obtained from the circuit relationship of the driving signal. dri =U gs +I acr *R control Drive control voltage U dri The discharge current I remains unchanged. acr When it gets bigger, I acr *R control This will increase, causing the gate-source voltage U applied to the MOSFET to... gs Reduce, thereby controlling the R of the MOSFETds When the resistance increases, I is automatically switched to I. acr As the current decreases, the entire control process is adaptive, with a fast dynamic response, ensuring rapid cycle-by-cycle limiting of I under pulse power supply driving conditions. acr The ability.

[0044] The present invention also provides a safe current control method for the aforementioned handheld integrated single-needle jet coagulation device, comprising the following steps:

[0045] Step S01: Establish an electrical path model for the coupling of single-needle jet current and arc impedance through experiments.

[0046] A single-needle suspended jet electrode was used. The resistance of the sliding rheostat was varied to simulate the degree of tissue coagulation during actual treatment. The distance *h* between the electrode and the ground electrode was adjusted to simulate the dynamic changes during the handheld process. The corresponding discharge voltage and discharge current were measured. The experimental platform is as follows: Figure 6 As shown.

[0047] Experimental data were collected for different distances h (0mm, 2mm, 4mm, 6mm, and 8mm), and the magnitude of the jet current was changed by altering the size of the sliding rheostat. The controlled variable method was used in the experiments: with h fixed, the resistance of the sliding rheostat was changed, thus altering the arc current; with the resistance of the sliding rheostat fixed, h was changed, and the changes in the current and arc impedance were measured. By accumulating experimental data under different combinations of sliding rheostat impedance and h, an electrical path model of the coupling between the single-needle jet current and the arc impedance was analyzed and derived.

[0048] Step S02: Establish discharge current I acr With arc impedance R acr The fitting mathematical model between them yields the discharge current I under different treatment intervals h. acr With the arc impedance R of the jet plume acr The relationship between the curves.

[0049] Discharge current I acr The current range threshold model is established based on the single-needle jet current and the arc impedance R. acr Coupled electrical path model. Experiments showed that, for the same treatment distance h, the path current decreases with increasing coagulation resistance, while the arc impedance decreases exponentially with increasing current. With a fixed current, the arc impedance increases with increasing h. The smaller the impedance, the larger the current flowing through the body, and the higher the electrical safety risk. Figure 7 As shown.

[0050] In step S02, I is established acr With R acrThe fitting mathematical model between them is an exponential model, and regardless of how the processing distance h changes, the fitting curve will eventually converge to the same exponential function. An impedance mathematical model between the single-needle jet plasma arc plume and the distance h between the human body can be established, and a dual current threshold (I0) is proposed. acr_min I acr_max (All values ​​are effective values) Regulation model, I acr_min The minimum discharge current for determining hemostasis and coagulation effects, I acr_max The upper limit of the device's safe current standard is the maximum value of the discharge current, and I acr_min I acr_max The relationship between the distance h and the curve follows an exponential curve model.

[0051] Due to the electrical safety requirements of the device during application, it is necessary to... acr Strict control measures must be implemented to ensure hemostasis and coagulation function while controlling the inflow of IgA into the human body. acr The invention reliably controls the safety threshold to ensure the electrical safety of the device operation. This invention can be based on I... acr_min vs. h and I acr_max The region formed by the two exponential model curves (vs. h) represents the effective safe current control range of the proposed handheld single-needle jet coagulation device. Considering human safety requirements, a dynamic mapping model between coagulation impedance and current is proposed using dual threshold constraints. The minimum effective current threshold (I0) is determined based on biomedical effects. acr_min To ensure effective blood clotting, the maximum safe current threshold (I) is determined based on the human body's safe current threshold. acr_max To avoid harm to the human body, and to deduce the reasonable range of change of arc impedance, this provides a basis for the design of power supply current limiting parameters, ensuring that the current is always within a safe and effective range during dynamic processing, and protecting human contact safety.

[0052] The range of variation of the variable resistor (R) limt_min R limit_max According to the maximum value I of the proposed double threshold current model, acr_max Design the minimum impedance R of this current limiting module circuit. limit_min Based on the minimum value I of the proposed dual threshold current model acr_min Design the maximum impedance R of this current limiting module circuit. limit_max Through the proposed R limt_min and R limit_max The design method ensures that, regardless of the random and dynamic changes in the distance h between the jet and the target coagulated tissue, the device held by the doctor user maintains effective coagulation and electrical safety, guaranteeing the safety, effectiveness, and reliability of the application.

[0053] Step S03: Using the biomedical effect current threshold and the human body safe current threshold as constraints, substitute the biomedical effect current threshold and the human body safe current threshold into the safe current range threshold model function respectively. and Two arc impedance ranges are derived from this. and Simultaneously, the intersection of the ranges of change of the two threshold impedances is taken. roll out By selecting the value of the current-limiting resistor within a range and combining it with the real-time changes in the impedance of the coagulation site during dynamic processing, the current-limiting parameters of the power supply are designed to ensure that the current flowing through the human body during dynamic processing remains stable within a safe and effective range, thus meeting the coagulation requirements while ensuring the safety of human contact.

[0054] This device employs a single-needle jet arc electrode, and its self-selection path effect was experimentally verified. Ar gas was used as the working gas to verify this effect in in vivo rabbit liver tissue coagulation. In the in vivo rabbit liver tissue coagulation experiment, a simulated real-life rabbit liver bleeding wound was used as the subject. The arc generated by the device exhibits autonomous path selection characteristics. Based on the impedance differences and damage state of the biological tissue, it automatically identifies the target area requiring coagulation and spreads outwards in a filamentary arc, adapting to the tissue's physiological structure and covering multi-dimensional coagulation pathways. Experimental results verify that the device can autonomously select the optimal coagulation pathway without human intervention. It ensures efficient coagulation by focusing the arc on key bleeding points while covering surrounding potential bleeding pathways through filamentary spread, verifying the effectiveness of the self-selection mechanism. This ensures that the device can accurately act on the target coagulation site in actual operation, improving the targeting and efficiency of hemostasis and coagulation.

[0055] The gas compatibility verification of the portable hemostasis and coagulation jet device was conducted through a comparative experiment of argon (Ar) and helium (He) discharge. The experiment confirmed that the device can discharge stably after changing to different working gases. Relying on the control mechanism such as the design of safe current limiting parameters, the current can be maintained within the range of human safety and effective coagulation threshold. This ensures human safety and maintains hemostasis and coagulation function. The device can be quickly adapted to new gases, maintaining the advantages of handheld and portable operation, and adapting to the diverse gas and energy output requirements of different coagulation scenarios.

[0056] The safety verification of the current-controlled human contact of the handheld integrated single-needle jet coagulation device was conducted through direct human hand contact experiments. Using helium and argon as the working gases, and relying on a safe current threshold model and dynamic current-limiting parameters, the device can adapt to the discharge characteristics of different gases in real time, precisely constraining the current flowing through the human body within the range of the minimum effective coagulation threshold and the maximum safe threshold for the human body. During the experiments, no safety hazards such as current overload or burns were observed when the hand came into contact with the two gas discharge jets. This confirms that the current control system can effectively ensure electrical safety and hemostasis / coagulation function under diverse gas conditions, verifying the actual protective capability of the design mechanism for human safety.

[0057] In biomedical applications, arc coagulation devices require a current regulation mechanism that can adapt to changes in tissue impedance while achieving safe and efficient hemostasis. This invention, based on the self-selection path effect of a single-needle jet arc, innovatively proposes a dual-threshold dynamic current limiting method. By establishing an arc current-coagulation impedance index model and combining the human body's safe current threshold with biomedical effect thresholds, the safe operating window for coagulation impedance is derived in reverse, and power supply current limiting parameters are designed accordingly. This method ensures coagulation uniformity through the arc's autonomous selection of the optimal conduction path while simultaneously controlling the current within a safe and effective range.

Claims

1. A handheld integrated single needle jet coagulation device, comprising a shell, one end of which is provided with an air inlet (6), and the other end is provided with an electrode unit (1), characterized in that: The charging module (5), lithium battery (4), AC power module (3), current limiting module (2) and electrode unit (1) are all located inside the housing and connected in sequence. The air inlet (6) is connected to the electrode unit (1) through a built-in hose.

2. The handheld integrated single needle jet coagulation device of claim 1, wherein: The AC power module (4) is a load-adaptive drive power supply.

3. The handheld integrated single needle jet coagulation device of claim 2, wherein: The circuit of the current limiting module (2) shown is a variable resistor, using a power transistor MOSFET, and controls the gate and source voltage U of the MOSFET. gs The size, thereby controlling the equivalent resistance R of the drain and source. ds .

4. The handheld integrated single-needle jet coagulation device as described in claim 3, characterized in that: Control U gs The specific method is as follows: a resistor R is connected in series with the source of the MOSFET. control In this MOSFET, the drain (D) and source (S) are connected in series with R. control Connected to the power output port, the drive voltage U of the drive circuit dri =U gs +I acr *R control Drive control voltage U dri The discharge current I remains unchanged. acr When it gets bigger, I acr *R control This will increase, causing the gate-source voltage U applied to the MOSFET to... gs Reduce, thereby controlling the R of the MOSFET ds When the resistance increases, I automatically... acr The current decreases.

5. A handheld integrated single-needle jet coagulation device as described in claim 1, characterized in that: The electrode unit (1) is a single-needle jet electrode structure.

6. The handheld integrated single-needle jet coagulation device as described in any one of claims 1-5, characterized in that: The device is 217mm long and 47mm in diameter.

7. A safe current control method for a handheld integrated single-needle jet coagulation device as described in any one of claims 1-6, characterized in that: Includes the following steps: Step S01: Establish an electrical path model for the coupling of single-needle jet current and arc impedance through experiments; Step S02: Establish discharge current I acr With arc impedance R acr The fitting mathematical model between them yields the discharge current I under different treatment intervals h. acr With the arc impedance R of the jet plume acr The relationship between the curves; Step S03: Using the biomedical effect current threshold and the human body safe current threshold as constraints, substitute the biomedical effect current threshold and the human body safe current threshold into the safe current range threshold model function respectively. and Two arc impedance ranges are derived from this. and Simultaneously, the intersection of the ranges of change of the two threshold impedances is taken. roll out The current-limiting resistor size is selected by the range, and the current-limiting parameters of the power supply are designed. Step S04: Use the current-limiting resistor and power supply current-limiting parameters obtained in step S03 to perform coagulation.

8. The safe current control method for the handheld integrated single-needle jet coagulation device as described in claim 7, characterized in that: The specific method of step S01 is as follows: Measure experimental data for different values ​​of h, and change the size of the sliding rheostat to change the magnitude of the jet current. Conduct the experiment using the controlled variable method: when h is fixed, change the resistance of the sliding rheostat to change the magnitude of the arc current; when the resistance of the sliding rheostat is fixed, change h and measure the changes in the current and arc impedance. By accumulating experimental data under different combinations of sliding rheostat impedance and h, analyze and derive the electrical path model of the coupling between the single-needle jet current and the arc impedance.

9. The safe current control method for the handheld integrated single-needle jet coagulation device as described in claim 8, characterized in that: Different distances with h values ​​of 0mm, 2mm, 4mm, 6mm, and 8mm were measured respectively.

Images