Intradermal swelling liquid injection syringe for skin grafting and taking area of burn patient

Abstract

The invention relates to an intradermal swelling liquid injection syringe for a skin grafting and taking area of a burn patient, and belongs to the technical field of medical instruments. The injector comprises an injector body and a mounting seat, an outer tube, a slidable needle tube, a piston, a liquid storage cavity, an injection steel needle, a liquid injection valve and a stop valve are arranged in the injector body, and the rear end of the injector body is connected with a distribution module. The first airtight space and the second airtight space are used for controlling piston propelling and needle tube displacement respectively, and needle inserting before injection and stable-pressure output in the injection process are achieved. The mounting seat is used for fixing the syringe on the body surface of a patient, the transparent observation window is arranged at the top and used for monitoring the needle inserting process, the skin-attaching face is made of soft medical materials, and compression on burnt skin is reduced while positioning precision is guaranteed. The system can dynamically adjust the injection speed based on the injection resistance change rate or the tissue tension state, the liquid injection uniformity is improved, and tissue damage is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to a syringe for intradermal injection of swelling fluid in a skin grafting area of ​​a burn patient. Background Art

[0002] In burn repair surgery, autologous skin transplantation is a common and important treatment method. In order to improve the quality of skin harvesting, reduce intraoperative bleeding and reduce patient pain, clinical practice usually injects tumescent fluid into the skin harvesting area to form a controllable separation layer between the dermis and subcutaneous tissue, thereby assisting in achieving uniform, shallow, low-resistance skin harvesting. Traditional injection methods mostly rely on manually held syringes, which have problems such as unstable injection depth, uncontrollable injection speed, and uneven local tissue swelling. When operating in the burn area, secondary damage may be caused to the fragile skin due to excessively fast injection or improper posture. In addition, the needle position or tissue expansion state cannot be observed in real time during the injection process, which also increases the risk of injection deviation and tissue rupture. Therefore, there is an urgent need for an injection system that can accurately control the injection depth and injection speed while ensuring the stability of the injection posture, and has tissue feedback capabilities, in order to meet the clinical requirements for increasing safety, controllability and patient comfort.

[0003] According to relevant published technologies, CN113018597A proposes a tumescent fluid syringe with controllable switch devices at both ends of the needle, thereby conveniently controlling the injection time and amount of the tumescent fluid. US20050027262A1 proposes an intravascular tumescent infusion device, which, through a fixing device provided on the syringe, enables the operator to precisely inject the tumescent fluid into the blood vessel. EP3714923A1 proposes a syringe for injecting contrast fluid into a blood vessel, which, by providing a light-emitting mechanism within the syringe, allows the operator to easily identify and distinguish bubbles in the injection solution.

[0004] The above technical solutions all propose various types of medical syringes for large-flow injection. However, there are currently few technical solutions that can adjust the injection rate according to the injection situation to meet the precision injection requirements for skin grafting and skin harvesting surgery.

[0005] The foregoing discussion of the background art is intended only to facilitate an understanding of the present invention. This discussion does not acknowledge or admit that any of the material referred to is part of the common general knowledge. Summary of the Invention

[0006] The purpose of the present invention is to provide a syringe for intradermal injection of tumescent fluid for skin grafting and harvesting areas of burn patients, the syringe comprising a syringe body and a mounting seat, wherein the syringe body is provided with an outer tube, a slidable needle tube, a piston, a liquid storage chamber, an injection needle, an injection valve and a stop valve, and a distribution module is connected to the rear end. The piston advancement and the needle tube displacement are controlled respectively by two airtight spaces A and B, thereby achieving needle insertion before injection and voltage-stabilized output during the injection process. The mounting seat is used to fix the syringe to the patient's body surface, and a transparent observation window is provided on the top for monitoring the needle insertion process. The skin-contacting surface is made of soft medical material, which reduces pressure on the burned skin while ensuring positioning accuracy. The system can dynamically adjust the injection speed based on the injection resistance change rate or the tissue tension state to improve the injection uniformity and reduce tissue damage.

[0007] The present invention adopts the following technical solution: a syringe for intradermal injection of tumescent fluid into a skin grafting area of ​​a burn patient, the syringe comprising:

[0008] A syringe body (100) and a mounting seat (200);

[0009] The syringe body (100) comprises:

[0010] a cylindrical outer tube (104);

[0011] a needle tube (106) disposed inside the outer tube (104) and slidable along the axial direction of the outer tube, the outer periphery of the needle tube being provided with a stopper (108), and the front end of the inner wall of the outer tube being provided with a stop step (110) to limit the maximum travel of the needle tube;

[0012] A needle tube seat (112) provided at the front end of the needle tube (106) for fixedly connecting the injection steel needle (102);

[0013] A piston (116) is disposed in the inner cavity of the needle tube (106), wherein the piston (116) is in sealing engagement with the inner wall of the needle tube (106), and a liquid storage cavity (120) for accommodating tumescent fluid is formed between the piston (116) and the needle tube seat;

[0014] A liquid injection valve (142) provided at the front end of the needle tube and in communication with the liquid storage chamber, for controlling the one-way flow of liquid between an external liquid injection device and the liquid storage chamber (120);

[0015] A stop valve (114) provided between the liquid storage chamber (120) and the injection steel needle, for controlling the on-off of the flow channel between the liquid storage chamber (120) and the injection steel needle (102);

[0016] A distribution module (150) is provided at the rear end of the needle tube, wherein the distribution module is provided with a main gas port (156), a gas port A (157) and a gas port B (158).

[0017] The gas port (157) is connected to the gas space (152) formed at the rear end of the piston (116) and is used to adjust the piston advance to compress the liquid storage chamber;

[0018] The B gas port (158) is in communication with the B space (154) formed between the outer wall of the needle tube and the outer tube, and is used to control the advancement or retraction of the entire needle tube (106) within the outer tube;

[0019] The mounting seat (200) is provided with a structural interface for fixing the syringe body, and is provided with a transparent observation window (202) for observing the state of the injection needle piercing the skin.

[0020] Preferably, the distribution module is communicatively coupled to a control module, and the control module is used to dynamically adjust the output air pressure of the main air port according to the resistance change signal during the piston advancement process, thereby controlling the advancement speed of the piston.

[0021] Preferably, a guide column (172) is provided at the rear end of the piston (116), and a tension and compression spring (174) is provided on the outer sleeve of the guide column. The two ends of the tension and compression spring are respectively fixed to the piston and the distribution module (150), and are used to assist the piston in resetting after the injection is completed and to limit its radial displacement during the advancement process.

[0022] Preferably, a micro-pressure sensor is provided in the tension-compression spring (174) for detecting the resistance from the liquid storage chamber during the advancement of the piston.

[0023] Preferably, the mounting seat is used to provide stable structural support for the syringe body to ensure that the posture does not deviate during the injection process; the mounting seat is entirely prepared and molded by injection molding polycarbonate or thermoplastic polyurethane.

[0024] Preferably, a fitting layer made of soft medical material is provided on the side of the mounting seat in contact with the patient's skin, so as to reduce the pressure on the patient's skin when the mounting seat is fixed to the surface of the burn area.

[0025] The beneficial effects achieved by the present invention are:

[0026] 1. The syringe proposed in this technical solution has a stable and controllable injection posture. The syringe body is spatially limited by the mounting seat. Combined with the preset incident angle structure and transparent observation window, it ensures that the injection needle penetrates the specific subcutaneous layer with a constant posture and can realize visual control of the injection depth, which significantly improves the accuracy and safety of the operation. It is particularly suitable for injection operations in sensitive tissues such as burn areas.

[0027] 2. The syringe proposed in this technical solution utilizes dual airtight control systems, A and B, acting on the piston and needle, respectively. This allows precise control of multiple stages of the needle insertion, injection, and needle withdrawal through pressure regulation at the main air port. Combined with pressure feedback and a resistance change rate determination mechanism, the injection speed can be dynamically adjusted, effectively preventing damage caused by excessive liquid injection or excessive tissue expansion.

[0028] 3. The syringe proposed in this technical solution has a fitting layer made of soft medical material, such as medical silicone, TPE or hydrogel, at the contact part between the mounting base and the skin. This can effectively alleviate the pressure and discomfort caused by the traditional hard support structure on the burn wound, while still having sufficient structural support force to ensure the stability and precision control requirements of the syringe while taking into account the patient experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention can be further understood from the following description in conjunction with the accompanying drawings. The components in the figures are not necessarily drawn to scale, but rather the emphasis is placed on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0030] Description of the accompanying symbols: 10-syringe; 100-syringe body; 102-injection needle; 104-outer tube; 106-needle tube; 108-stop; 110-stop step; 112-needle tube seat; 114-stop valve; 116-piston; 120-liquid storage chamber; 142-liquid injection valve; 144-liquid adding tube; 150-distribution module; 152-space A; 154-space B; 156-main gas port; 15 7-A gas port; 158-B gas port; 172-Guide column; 174-Tension and compression spring; 180-Micro pressure sensor; 200-Mounting seat; 202-Observation window; 500-Operating system; 502-Bus; 504-Processor; 506-Main memory; 508-Read-only memory; 510-Storage device; 512-Display; 514-Input device; 516-Cursor control device; 518-Network device;

[0031] Figure 1 、 Figure 2 Schematic diagram of the internal structure of the syringe in an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of the syringe according to an embodiment of the present invention after the needle tube is extended;

[0033] Figure 4 Schematic diagram of a micro-pressure sensor installed in a tension and compression spring in an embodiment of the present invention;

[0034] Figure 5 Schematic diagram of the framework of the computer system used by the control module in the embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with its embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. For those skilled in the art, other systems, methods and / or features of the present embodiment will become apparent after reviewing the following detailed description. It is intended that all such additional systems, methods, features and advantages are included in this specification. Included within the scope of the present invention and protected by the appended claims. Additional features of the disclosed embodiments are described in the following detailed description, and these features will be apparent from the following detailed description.

[0036] The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating an orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or component referred to must have a specific orientation. The terms used in the drawings to describe the positional relationship are only for illustrative purposes and cannot be understood as limiting this patent. For those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0037] Example 1: For example, a syringe for intradermal injection of tumescent fluid into a skin grafting area of ​​a burn patient is provided, the syringe comprising:

[0038] syringe body and mounting base;

[0039] The syringe body comprises:

[0040] a cylindrical outer tube;

[0041] A needle tube is disposed inside the outer tube and can slide axially along the outer tube, the outer periphery of the needle tube is provided with a stopper, and the front end of the inner wall of the outer tube is provided with a stop step to limit the maximum stroke of the needle tube;

[0042] A needle tube seat is provided at the front end of the needle tube, and is used to fix the injection needle;

[0043] A piston is disposed in the inner cavity of the needle tube, the piston being in sealing engagement with the inner wall of the needle tube, and forming a liquid storage cavity for containing tumescent fluid between the piston and the needle tube seat;

[0044] An injection valve is provided at the front end of the needle tube and is connected to the liquid storage chamber, and is used to control the one-way flow of liquid between the external injection device and the liquid storage chamber;

[0045] A stop valve is provided between the liquid storage chamber and the injection steel needle, for controlling the flow passage between the liquid storage chamber and the injection steel needle;

[0046] The distribution module is provided at the rear end of the needle tube, and the distribution module is provided with a main gas port, a gas port A and a gas port B.

[0047] Wherein, the A gas port is in communication with the A space formed at the rear end of the piston, and is used to adjust the piston advance to compress the liquid storage chamber;

[0048] The B gas port is connected to the B space formed between the outer wall of the needle tube and the outer tube, and is used to control the advancement or retraction of the entire needle tube in the outer tube;

[0049] The mounting seat is provided with a structural interface for fixing the syringe body, and is provided with a transparent observation window for observing the state of the injection needle piercing the skin.

[0050] Preferably, the distribution module is communicatively coupled to a control module, and the control module is used to dynamically adjust the output air pressure of the main air port according to the resistance change signal during the piston advancement process, thereby controlling the advancement speed of the piston.

[0051] Preferably, a guide column is provided at the rear end of the piston, and a tension and compression spring is provided on the outer sleeve of the guide column. The two ends of the tension and compression spring are respectively fixed to the piston and the distribution module, for assisting the piston to reset after the injection is completed and limiting its radial displacement during the advancement process.

[0052] Preferably, a micro-pressure sensor is provided in the tension-compression spring for detecting the resistance from the liquid storage chamber during the advancement of the piston.

[0053] Preferably, the mounting seat is used to provide stable structural support for the syringe body to ensure that the posture does not deviate during the injection process; the mounting seat is entirely prepared and molded by injection molding polycarbonate or thermoplastic polyurethane.

[0054] Preferably, the side of the mounting base that contacts the patient's skin is provided with a bonding layer made of soft medical material, which is used to reduce the pressure on the patient's skin when the mounting base is fixed to the surface of the burn area.

[0055] In the attached Figure 1 , Attachment Figure 2 and attached Figure 3A schematic diagram of the internal structure of the syringe is shown in FIG. In an exemplary embodiment, the syringe 10 includes a syringe body 100 and a mounting base 200 used in conjunction with the syringe body 100. The syringe body 100 is used to inject a preset dose of swelling fluid into the patient's subcutaneous tissue during clinical operation to form a subcutaneous swelling layer, thereby providing an operating space for subsequent skin excision or processing. The mounting base 200 is constructed as a stable structure, which is used to stably limit the spatial placement posture of the syringe body 100 after at least part of the front end of the syringe body 100 is inserted into the mounting base 200, thereby keeping the posture of the injection needle 102 stable during the injection process.

[0056] Furthermore, the mounting seat 200 can be an injection molded part or a polymer material structural part produced by additive technology, or a polymer material structural part produced by machining, so that the mounting seat 200 can be mass-produced and the overall size of the mass-produced mounting seat 200 can be guaranteed to be consistent.

[0057] The bottom of the mounting base 200 contacts the surface of the patient's skin, and the contact surface of the mounting base 200 with the skin is preferably made of soft medical materials, such as medical silicone, thermoplastic TPE, polyurethane foam, medical hydrogel, etc., to reduce irritation to the patient's skin. In addition, the mounting base 200 is preferably attached to the predetermined injection area in the form of a fixing belt, an adhesive structure, a puncture auxiliary bracket, etc. Preferably, the mounting base 200 can be designed to have several specifications with preset injection incident angles, for example, it can have preset specifications of 10°, 15°, 20° or more, so as to select a suitable injection angle and height according to the patient's anatomical structure, and ensure that the injection needle 102 maintains a constant incident angle during the needle pushing process. Preferably, the mounting base 200 is provided with a pre-calibrated needle port guide channel or a scale marking structure to assist the operator in aligning the needle port of the injection needle 102 with the target injection point on the patient's skin.

[0058] Furthermore, to enhance visualization and safety during the injection process, a transparent observation window 202 is provided on the top of the mounting base 200. The observation window 202 is made of transparent plastic, glass, or other medical optical materials. This allows the operator to directly observe the entire process of the injection needle 102 piercing the skin with the naked eye or with the help of a camera (such as an endoscopic camera) to record the entire process, thereby determining the insertion depth, angle, and alignment of the needle. Optionally, the observation window 202 is provided with a positioning auxiliary scale or a window frame for calibrating the insertion point or determining the penetration status of the needle tip.

[0059] In an exemplary embodiment, the syringe body 100 includes a cylindrical hollow outer tube 104, preferably made of medical-grade polycarbonate or transparent polypropylene, which provides excellent structural strength and compatibility with the drug solution. A tubular needle tube 106 is disposed within the outer tube 104 along its central axis. The needle tube 106 is coaxially arranged with the outer tube 104 and slidably mounted therewith. The outer diameter of the needle tube 106 is smaller than the inner diameter of the outer tube 104, forming a limited gap between the outer tube 104 and the outer tube 104, thereby allowing the needle tube 106 to reciprocate axially within the outer tube 104.

[0060] Preferably, to limit the maximum travel of the needle tube 106 within the outer tube 104 and ensure it does not escape from the outer tube structure when withdrawn to its limit position, the outer circumference of the needle tube is provided with a radially raised stop 108. This stop 108 can take the form of an annular flange or a stepped shoulder, located at the rear end of the needle tube 106 relative to the injection end. Accordingly, a stop step 110 is provided at a corresponding position on the front end of the inner wall of the outer tube 104. This stop step 110 cooperates with the stop 108 to form an axial limit.

[0061] When the needle tube 106 moves along the central axis of the outer tube 104 to its maximum forward position, the stopper 108 engages the stop step 110, thereby preventing the needle tube from moving further, ensuring that it remains within the structural range of the outer tube and preventing accidental removal due to air pressure or elastic recovery. In addition, the fit between the outer edge of the stopper 108 and the inner wall of the outer tube 104 is preferably a clearance fit, which ensures the limiting function while not affecting the sliding flexibility of the entire needle tube.

[0062] Further preferably, the structural material of the stop 108 and the stop step 110 can be designed with reinforced polymer or inlaid metal rings to improve fatigue resistance and dimensional retention during multiple reciprocating motions.

[0063] In an exemplary embodiment, the front end of the needle tube 106 is fixedly connected to a needle tube seat 112. The needle tube seat 112 can be a unitary injection-molded structure, a replaceable modular structure, or a Luer threaded connector structure, which is used to achieve the structural connection between the needle tube 106 and the front injection assembly. The needle tube seat 112 is used to seal the needle tube 106 and the injection needle 102. The injection needle 102 is preferably inserted into the central through-hole of the needle tube seat 112, thereby forming a stable liquid drug delivery path.

[0064] In an exemplary embodiment, a stop valve 114 is provided in front of the needle tube 106, close to the needle tube seat 112. The stop valve 114 is provided on the fluid path between the liquid storage chamber 120 inside the needle tube 106 and the injection needle 102. An axially through-going infusion channel is formed in the middle portion of the stop valve 114, the front end of which is connected to the proximal opening of the injection needle, and the rear end is connected to the liquid storage chamber inside the needle tube. When the stop valve is in the on state, the swelling fluid in the liquid storage chamber 120 can flow into the injection needle 102 along the infusion channel and be injected into the patient's body; and when the stop valve is in the closed state, the infusion channel will be deflected or blocked, thereby realizing the cut-off control of the flow of the liquid medicine.

[0065] To accommodate different operational requirements, the shutoff valve 114 can be controlled in a variety of ways. For example, the shutoff valve 114 can be configured as an electrically controlled, magnetically controlled, or mechanically controlled type, allowing the operator to flexibly switch the on / off state of the infusion channel during the injection preparation and injection execution stages.

[0066] Preferably, in order to prevent backflow due to needle blockage or back pressure from the patient's subcutaneous tissue during the injection process, the stop valve 114 can be configured to have a one-way check structure, or maintain a constant fluid direction in the open state to ensure safe and effective injection of the drug solution.

[0067] In an exemplary embodiment, a piston 116 is disposed within the inner cavity of the needle tube 106. The piston 116 is slidably disposed along the axial direction of the needle tube 106 and forms a dynamic airtight or liquid-tight fit with the inner wall of the needle tube 106. Preferably, the outer periphery of the piston 116 is coated with a medical-grade elastic sealing ring, such as a silicone sealing ring or a polytetrafluoroethylene sealing lip structure, to ensure a stable axial seal during the advancement process, thereby preventing leakage of the drug solution or uneven advancement.

[0068] Preferably, the space between the piston 116 and the needle holder 112 forms a sealed chamber, namely a liquid storage chamber 120. The liquid storage chamber 120 is used to accommodate the pre-filled swelling fluid or the volume of liquid medicine injected through the injection valve before injection.

[0069] During the injection operation, the piston 116 moves along the central axis of the needle tube 106 toward the needle tube seat 112 under the action of the driving force driving its rear end. During the forward movement, the piston 116 gradually compresses the liquid storage chamber 120, so that the swelling fluid in the liquid storage chamber 120 passes through the infusion channel connected to the needle tube seat 112, and is finally steadily pushed out of the injection needle 102 and injected into the patient's subcutaneous tissue.

[0070] In a preferred embodiment, an injection valve is provided at the front end of the needle tube 106. The injection valve 142 is used to control the process of introducing the tumescent fluid from an external injection device into the liquid storage chamber 120 through the liquid adding tube 144. One end of the injection valve 142 is connected to the interior of the liquid storage chamber 120 through a channel, and the other end is provided with an external port, which can be connected to the injection pipeline and communicated with an external injection device (such as an injection pump, a syringe, an automatic perfusion system, etc.). The injection valve 142 is preferably designed as a controllable one-way valve structure, which only allows liquid to flow in the injection direction, that is, to be injected into the liquid storage chamber 120 from the outside, to prevent the liquid from flowing back into the pipeline system due to cavity pressure fluctuations or reaction forces during the injection process.

[0071] Preferably, the injection valve 142 can be a solenoid valve, a micro-rotary valve, or a self-restoring check valve, and can be linked with the main control unit to control its conduction state to ensure that the time window and pressure state of the injection process meet preset conditions. Preferably, the injection valve 142 automatically remains closed during the non-injection phase to prevent air from entering or accidental liquid overflow.

[0072] Furthermore, in an exemplary embodiment, a distribution module 150 is provided at the rear end of the needle tube 106. The distribution module 150 is used to implement multi-channel air pressure control and spatial sealing management of the syringe. An axial seal is provided between the distribution module 150 and the needle tube 106 to form an airtight connection area, and the interior thereof is enclosed to form a space A 152. The boundary of the space A 152 is defined by the sealing structure between the inner wall of the needle tube 106, the rear surface of the piston 116, and the front surface of the distribution module 150. The space A 152 is used to regulate the application of air pressure during the movement of the piston, directly acting on the back of the piston to achieve control of its advancement and withdrawal.

[0073] On the other hand, the rear surface of the stopper 108, the outer wall of the needle tube 106, and the inner wall of the outer tube 104 collectively enclose a second space 154. This second space 154 surrounds the outer periphery of the needle tube 106 and serves as a pneumatic drive space for controlling the entire advancement or retraction of the needle tube 106 within the outer tube 104, with an independent air pressure control passage.

[0074] Preferably, in order to achieve independent regulation and coordinated driving of the two airtight spaces, space A 152 and space B 154, the distribution module 150 is provided with at least three gas ports, including:

[0075] Main gas port 156: used to connect to an external gas pressure regulating device (such as an air pump, gas controller) to provide a positive or negative pressure gas source;

[0076] Air port A 157: communicates with space A 152 and controls the advancement or retraction of piston 116 by regulating air pressure, thereby affecting the volume change of the liquid storage chamber and the liquid injection process;

[0077] The B gas port 158 ​​is connected to the B space 154 and is used to control the movement state of the entire needle tube 106 in the outer tube 104 to achieve the push-out and retraction of the injection needle 102.

[0078] The distribution module 150 can control the opening and closing of the gas paths between the main gas port 156 and the gas port A 157 , and between the main gas port 156 and the gas port B 158 , respectively, thereby controlling the advancement and retreat of the piston 116 and the needle tube 106 .

[0079] In actual operation, the two working modes of the allocation module 150 include:

[0080] (1) When the main gas port 156 is connected to the A gas port 157, the gas pressure regulating device will be set to provide positive pressure gas, illustratively, a pressure slightly higher than atmospheric pressure, such as 105-120 kPa, and connect the positive pressure gas environment to the A space 157. Since the A space 157 is the closed volume defined between the back of the piston 116 and the rear end of the needle tube 106, the gas pressure will directly act on the rear end surface of the piston 116, generating a thrust to push the piston 116 forward along the axis of the needle tube 106.

[0081] The forward movement of piston 116 compresses the volume of the fluid reservoir 120 in front of it, thereby pushing the tumescent fluid in the fluid reservoir 120 along the infusion channel to the needle holder and then injected into the patient's subcutaneous tissue through injection needle 102. This process can be controlled by adjusting the output pressure of the main air port 156 or introducing a step-by-step pressure increase to control the injection speed and duration, thereby achieving a sustained-release or staged injection strategy.

[0082] In this working mode, the B gas port 158 ​​remains closed to ensure that the outer tube 104 and the needle tube 106 are in a relatively static state without axial relative displacement, thereby maintaining the current position of the injection needle.

[0083] (2) When the main gas port 156 and the secondary gas port 158 ​​are connected, the gas pressure regulating device introduces a preset positive or negative pressure gas into the secondary space 154. Since the secondary space 154 is formed by the outer wall of the needle tube, the stop structure and the inner wall of the outer tube, the applied gas pressure will form a uniformly distributed axial force around the outer periphery of the needle tube 106, thereby driving the entire needle tube 106 to move along the axis of the outer tube.

[0084] Specifically, when the main air port 156 outputs a positive pressure environment to the B air port 158, the air pressure in the B space 158 rises, which pushes the needle tube 106 forward as a whole, causing the injection needle 102 to gradually extend from the front end of the outer tube 104, thus achieving the needle insertion action before injection.

[0085] On the other hand, if the main air port 156 outputs a negative pressure environment to the B air port 158, for example, an air pressure of 90 to 95 kPa lower than atmospheric pressure or slightly negative pressure, the B space 158 is evacuated to form suction, and the needle tube retracts backward under the action of the external atmospheric pressure and the negative pressure difference, completing the needle recovery action, which is suitable for preparation before injection or needle collection after injection.

[0086] In this mode, the gas port 157 should remain closed to prevent the piston 116 from being pressed forward by mistake during the non-injection phase, causing premature leakage of the drug solution or disorder in the injection path.

[0087] In some preferred embodiments, space A / B is hermetically sealed by an annular sealing ring, a labyrinth seal or a fluororubber soft sealing ring structure to ensure that it maintains a stable volume under different air pressure conditions without obvious leakage, thereby improving the system's action repeatability and injection accuracy.

[0088] In some preferred embodiments, to ensure a stable injection rate and uniform liquid distribution, the air pressure regulating device connected to the main air port 156 is precisely adjusted by the control module. For example, this can be achieved by adjusting the air pressure applied to the back of the piston, setting the speed of the micromotor, or controlling the spring release rate. In preferred embodiments, the piston advances in a controlled, progressive or slow-release manner, ensuring uniform distribution of the tumescent fluid along the tissue throughout the injection path, reducing tissue shear forces, and improving the patient experience.

[0089] In some preferred embodiments, a guide post 172 is provided at the rear end of the piston 116. The guide post 172 extends along the axial direction of the syringe body and can be inserted into a guide hole provided in the distribution module. A tension and compression spring 174 is provided on the outside of the guide post 172. The tension and compression spring 174 allows for stretching and compression to a certain extent and has the ability to return to its original length, thereby providing elastic force during injection and retraction. One end of the tension and compression spring 174 is fixed to the rear end surface of the piston 116, and the other end is fixed to a side surface of the distribution module 150 opposite to the rear end surface of the piston 116.

[0090] Through the above structure, the piston 116 is first limited in radial displacement during axial movement through the cooperation of the guide column 172 and the guide hole, thereby preventing eccentric movement from causing increased friction or unstable propulsion, and ensuring that the piston slides stably along the axis of the needle tube. The guide column 172 is used to limit the movement channel of the tension and compression spring 174 during compression and rebound, thereby preventing the tension and compression spring 174 from deforming, bending or becoming unstable under stress, thereby improving energy transfer efficiency and structural life. Furthermore, the tension and compression spring 174 has a limiting buffering function, which can absorb part of the remaining kinetic energy when the piston 116 is pushed to the terminal position, preventing the piston from impacting the front-end structure; finally, the restoring force of the tension and compression spring 174 after stretching can prompt the piston 116 to move in the return direction, thereby assisting the piston 116 in resetting after injection, facilitating preparation for the next injection.

[0091] The above-mentioned structural combination improves the stability, response speed and reusability of the entire injection system, and is particularly suitable for multiple controllable injections or precise swelling fluid injection scenarios.

[0092] Embodiment 2: This embodiment should be understood to include at least all the features of any one of the aforementioned embodiments and to be further improved thereon.

[0093] In a preferred embodiment, the injector can combine external observation with internal feedback mechanism to dynamically monitor the response characteristics of skin tissue during the injection process, and adjust the injection speed accordingly in real time to ensure the safety of the injection process and the uniformity of the drug solution distribution.

[0094] Specifically, the operator can judge the injection status through the following two types of inspection methods:

[0095] First, the operator can use visual observation or a rebound test tool to determine the skin tension state of the injection area. During the injection process, if the skin surface at the injection site shows significant tension, becomes lighter in color, or has an "orange peel" appearance, or if the tissue rebound capacity measured by the rebound meter decreases significantly, it indicates that the local tissue has reached or is close to saturation. At this time, the injection rate should be reduced or the injection procedure should be suspended to prevent skin tears, blister formation, or tissue necrosis caused by excessive local tissue expansion.

[0096] Secondly, as attached Figure 4As shown, the tension and compression spring 174 in the A space 152 of the syringe is provided with an integrated micro-pressure sensor 180 for real-time detection of the internal flow resistance caused by the tumescent fluid during the piston advancement process. The data collected by the sensor can be transmitted to an external control module by wired or wireless communication, and the control module statistically forms a continuous resistance-time curve. When a sharp upward trend is detected in the curve, it means that the current tumescent fluid encounters strong resistance during the injection process, which may be caused by increased tissue tension, path obstruction or needle insertion angle deviation. At this time, the control module automatically reduces the injection speed according to the set pressure change threshold, or enters a maintenance state until the resistance returns to a stable state.

[0097] Exemplarily, the injection control process is modeled as a speed control model based on the resistance change rate, which is executed by the control module. Exemplarily, the control model is set as follows:

[0098] R(t): injection propulsion resistance, measured in real time by an integrated micro-pressure sensor;

[0099] dR / dt: The derivative of injection resistance with respect to time, indicating the resistance growth rate;

[0100] v(t): injection velocity, illustratively in mL / s;

[0101] R crit : The set resistance change threshold, exceeding this value indicates that the tissue has entered an excessive resistance state;

[0102] V0: initial / default injection speed;

[0103] α: deceleration coefficient, used to control the speed reduction amplitude;

[0104] Δt: control system response period or sampling time interval.

[0105] For example, corresponding control strategies are set for three injection states:

[0106] (1) Resistance change stable state:

[0107] That is, when:

[0108]

[0109] The current injection speed is maintained, that is: v(t+Δt)=v(t).

[0110] (2) Resistance rises rapidly:

[0111]

[0112] Then the injection speed is controlled to decrease proportionally:

[0113]

[0114] where v min It is the lower limit of safe injection speed, which can be 0 or other appropriate values.

[0115] (3) When resistance begins to decrease or return to normal:

[0116] You can set:

[0117]

[0118] Embodiment 3: This embodiment should be understood to include at least all the features of any one of the aforementioned embodiments and to be further improved thereon.

[0119] Further, as attached Figure 5 As shown, an exemplary embodiment of the computer system used by the control module is described; the computer system 500 can be used to identify and judge the data storage, calculation and result output process of each working module in the system.

[0120] Illustratively, computer system 500 includes a bus 502 or other communication mechanism for communicating information, and one or more processors 504 coupled with bus 502 for processing information; processor 504 may be, for example, one or more general-purpose microprocessors.

[0121] The computer system 500 also includes a main memory 506, such as a random access memory (RAM), a cache, and / or other dynamic storage device, coupled to the bus 502 for storing information and instructions to be executed by the processor 504; the main memory 506 may also be used to store temporary variables or other intermediate information during execution of the instructions to be executed by the processor 504; these instructions, when stored in a storage medium accessible to the processor 504, present the computer system 500 as a special-purpose machine customized to perform the operations specified in the instructions.

[0122] The computer system 500 may also include a read-only memory (ROM) 508 or other static storage device coupled to the bus 502 for storing static information and instructions for the processor 504; a storage device 510 such as a magnetic disk, optical disk, or USB drive (flash drive) will be coupled to the bus 502 for storing information and instructions.

[0123] Furthermore, coupled to the bus 502 may also include a display 512 for displaying various information, data, media, etc., and an input device 514 for allowing a user of the computer system 500 to control, manipulate, and / or interact with the computer system 500 .

[0124] A preferred way to interact with the management system may be through a cursor control device 516, such as a computer mouse or similar control / navigation mechanism.

[0125] Furthermore, the computer system 500 may further include a network device 518 coupled to the bus 502; wherein the network device 518 may include, for example, a wired network card, a wireless network card, a switching chip, a router, a switch, and other components;

[0126] In general, the terms "engine," "component," "system," "database," etc., used herein may refer to logic embodied in hardware or firmware, or to a collection of software instructions, possibly with entry and exit points, written in a programming language such as Java, C, or C++; software components may be compiled and linked into executable programs, installed in a dynamic link library, or may be written in an interpreted programming language (such as BASIC, Perl, or Python); it will be understood that software components may be callable from other components or from themselves, and / or may be called in response to detected events or interrupts.

[0127] Software components configured to execute on a computing device may be provided on a computer-readable medium, such as a compact disc, digital video disc, flash drive, magnetic disk, or any other tangible medium, or as a digital download (and may be initially stored in a compressed or installable format that requires installation, decompression, or decryption prior to execution); such software code may be stored in part or in whole on a memory device of the executing computing device for execution by the computing device; the software instructions may be embedded in firmware, such as an EPROM; it will also be understood that hardware components may be composed of connected logic units (such as gates and flip-flops), and / or may be composed of programmable units (such as a programmable gate array or processor).

[0128] Computer system 500 may implement the techniques described herein using custom hard-wired logic, one or more ASICs or FPGAs, firmware, and / or program logic that, in combination with the computer system, renders computer system 500 a special-purpose computing device.

[0129] In accordance with one or more embodiments, the techniques herein are performed by computer system 500 in response to processor 504 executing one or more sequences of one or more instructions contained in main memory 506; such instructions may be read into main memory 506 from another storage medium, such as storage device 510; execution of the sequences of instructions contained in main memory 506 causes processor 504 to perform the process steps described herein; in alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions.

[0130] As used herein, the term "non-transitory media" and similar terms refer to any medium that stores data and / or instructions that cause a machine to operate in a specific manner; such non-transitory media may include non-volatile media and / or volatile media; non-volatile media include, for example, optical or magnetic disks, such as storage device 510; and volatile media include dynamic memory, such as main memory 506.

[0131] Among them, common forms of non-transitory media include, for example, floppy disks, diskettes, hard disks, solid-state drives, magnetic tape or any other magnetic data storage medium, CD-ROMs, any other optical data storage medium, any physical medium with a pattern of holes, RAM, PROM and EPROM, FLASH-EPROM, NVRAM, any other memory chip or cartridge, and networked versions thereof.

[0132] Non-transient media are distinct from, but may be used in conjunction with, transmission media; transmission media participate in the transmission of information between non-transient media; for example, transmission media include coaxial cables, copper wires, and optical fibers, including the wires that comprise bus 502; transmission media may also take the form of sound or light waves, such as radio waves and infrared data communications.

[0133] Although the present application has been described above with reference to various embodiments, it will be understood that many changes and modifications may be made without departing from the scope of the present application. That is, the methods, systems, and devices discussed above are examples. Various configurations may omit, replace, or add various processes or components as appropriate. For example, in alternative configurations, the methods may be performed in an order different from that described, and / or various components may be added, omitted, and / or combined. Moreover, features described with respect to certain configurations may be combined in various other configurations, such as different aspects and elements of the configurations may be combined in a similar manner. Furthermore, as technology develops, the elements therein may be updated, i.e., many of the elements are examples and do not limit the scope of the present disclosure or the claims.

[0134] Specific details are given in the description to provide a thorough understanding of the exemplary configurations, including implementations. However, the configurations can be practiced without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques have been shown without unnecessary detail to avoid obscuring the configurations. This description provides only example configurations and does not limit the scope, applicability, or configurations of the claims. Instead, the foregoing description of the configurations will provide those skilled in the art with an enabling description for implementing the described techniques. Various changes may be made to the function and arrangement of the elements without departing from the spirit or scope of the present disclosure.

[0135] In summary, it is intended that the above detailed description be considered illustrative rather than restrictive, and it should be understood that the above embodiments are intended to be merely illustrative of the present invention and not to limit the scope of protection of the present invention. After reading the contents of the present invention, a skilled person may make various changes or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims

1. A syringe for intradermal injection of tumescent fluid in a skin grafting area of ​​a burn patient, characterized in that: The syringe comprises: A syringe body (100) and a mounting seat (200); The syringe body (100) comprises: a cylindrical outer tube (104); a needle tube (106) disposed inside the outer tube (104) and slidable along the axial direction of the outer tube, the outer periphery of the needle tube being provided with a stopper (108), and the front end of the inner wall of the outer tube being provided with a stop step (110) to limit the maximum travel of the needle tube; A needle tube seat (112) provided at the front end of the needle tube (106) for fixedly connecting the injection steel needle (102); A piston (116) is disposed in the inner cavity of the needle tube (106), wherein the piston (116) is in sealing engagement with the inner wall of the needle tube (106), and a liquid storage cavity (120) for accommodating tumescent fluid is formed between the piston (116) and the needle tube seat; A liquid injection valve (142) provided at the front end of the needle tube and in communication with the liquid storage chamber, for controlling the one-way flow of liquid between an external liquid injection device and the liquid storage chamber (120); A stop valve (114) provided between the liquid storage chamber (120) and the injection steel needle, for controlling the on-off of the flow channel between the liquid storage chamber (120) and the injection steel needle (102); A distribution module (150) is provided at the rear end of the needle tube, wherein the distribution module is provided with a main gas port (156), a gas port A (157) and a gas port B (158). The gas port (157) is in communication with the gas space (152) formed at the rear end of the piston (116), and is used to adjust the piston advance to compress the liquid storage chamber; The B gas port (158) is in communication with the B space (154) formed between the outer wall of the needle tube and the outer tube, and is used to control the advancement or retraction of the entire needle tube (106) within the outer tube; The mounting seat (200) is provided with a structural interface for fixing the syringe body, and is provided with a transparent observation window (202) for observing the state of the injection needle piercing the skin.

2. The syringe according to claim 1, wherein The distribution module is communicatively coupled to the control module, and the control module is used to dynamically adjust the output air pressure of the main air port according to the resistance change signal during the piston advancement process, thereby controlling the advancement speed of the piston.

3. The syringe according to claim 1, wherein A guide column (172) is provided at the rear end of the piston (116), and a tension and compression spring (174) is provided on the outer sleeve of the guide column. The two ends of the tension and compression spring are respectively fixed to the piston and the distribution module (150), and are used to assist the piston in resetting after the injection is completed and to limit its radial deviation during the advancement process.

4. The syringe according to claim 3, wherein A micro-pressure sensor is provided in the tension-compression spring (174) for detecting the resistance of the piston from the liquid storage chamber during the advancement process.

5. The syringe according to claim 1, wherein The mounting seat is used to provide stable structural support for the syringe body to ensure that the posture does not deviate during the injection process; the mounting seat is entirely prepared and molded using injection-molded polycarbonate or thermoplastic polyurethane.

6. The syringe according to claim 1, wherein: The side of the mounting seat that contacts the patient's skin is provided with a fitting layer made of soft medical material, which is used to reduce the pressure on the patient's skin when the mounting seat is fixed to the surface of the burn area.

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