A constant temperature control speed device for deep venous catheter infusion

Abstract

The present application relates to the technical fields of deep vein catheterization infusion, in particular to a constant temperature control speed device for deep vein catheterization infusion, comprising an infusion catheter head and an infusion tube, one side of the infusion catheter head is fixedly connected with one end of the infusion tube. The present application sets a piston frame structure with spiral flow guide grooves inside the infusion tube, changes the fluid dynamics behavior of traditional plunger type propulsion, when the piston frame reciprocates, the liquid medicine forms spiral jet flow under the guidance of the spiral flow guide grooves, forced fluid generates circumferential rotation, effectively destroys the stationary state of the pipe wall boundary layer, converts the axial thrust into rotational shear force, not only reduces the flow resistance, but also eliminates the stagnant zone at the front end of the piston, realizes uniform delivery of the whole cross section, makes the liquid medicine always maintain a dynamic mixing state during the pushing process, avoids density stratification and sedimentation, especially suitable for the infusion of fat emulsion, amino acid and other easily separated nutrient solutions, greatly improves the stability of the infusion.

Description

Technical Field

[0001] This invention relates to the field of deep vein catheterization and infusion technology, specifically to a constant temperature and rate control device for deep vein catheterization and infusion. Background Technology

[0002] In clinical intensive care and long-term intravenous nutritional support, deep vein catheterization is a common treatment method used for rapid fluid resuscitation, drug administration, or parenteral nutrition infusion.

[0003] Existing conventional infusion pumps mostly use squeeze or plunger propulsion principles. When faced with the special working conditions of high impedance, small diameter, and long catheters in deep vein placement, they generally suffer from problems such as large fluid pulsation, easy formation of dead zones, lag in temperature control, and insufficient biocompatibility. Traditional devices are difficult to achieve stable delivery and precise temperature control of viscous drugs or low-temperature nutrient solutions. Furthermore, during long-term infusion, protein deposits or microthrombi are prone to form on the tube wall, increasing the risk of tube blockage and infection.

[0004] Therefore, we propose a constant temperature and rate control device for deep vein catheter infusion. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a constant temperature and rate control device for deep vein catheter infusion. By incorporating a piston frame structure with a spiral guide groove inside the infusion tube, the fluid dynamics of traditional plunger-type propulsion are altered. When the piston frame reciprocates, the medication forms a spiral jet under the guidance of the spiral guide groove, forcing the fluid to rotate circumferentially. This effectively disrupts the static state of the tube wall boundary layer, converting axial thrust into swirling shear force. This not only reduces flow resistance but also eliminates the stagnation zone at the piston tip, achieving uniform delivery across the entire cross-section. This ensures that the medication remains dynamically mixed during delivery, preventing density stratification and precipitation. It is particularly suitable for the infusion of easily precipitated nutrient solutions such as fat emulsions and amino acids, significantly improving the stability and bioavailability of the infusion.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a constant temperature and rate control device for deep vein catheterization infusion, comprising an infusion catheter head and an infusion tube, wherein one side of the infusion catheter head is fixedly connected to one end of the infusion tube, and the interior of the infusion tube communicates with the interior of the infusion catheter head; a front piston frame and a rear piston frame are slidably provided on both sides of the interior of the infusion tube, and both the front piston frame and the rear piston frame are provided with spiral guide grooves on their surfaces, and spiral guide frames are fixedly provided on the surfaces of both spiral guide grooves; an annular mounting groove is provided on the outer circumferential surface of the infusion tube, and a front excitation coil and a rear excitation coil are respectively wound around both sides of the outer circumferential surface of the annular mounting groove, the front excitation coil and the rear excitation coil being used to drive the front piston frame and the rear piston frame to reciprocate inside the infusion tube; a magnetic core frame is fixedly provided in the middle of the interior of both the front excitation coil and the rear excitation coil.

[0007] Preferably, the outer circumferential surfaces of the front piston holder and the rear piston holder are provided with annular sealing grooves, and medical silicone O-rings are embedded in the sealing grooves; a heat insulation sleeve is fixedly provided on the outer circumferential surface of the annular mounting groove.

[0008] Preferably, a plurality of external Hall sensor arrays are fitted onto the inner surface of the annular mounting groove and inside the front and rear excitation coils, and the plurality of external Hall sensor arrays are arranged at equal angles about the central axis of the annular mounting groove; sensor mounting brackets are fixedly provided at both ends of the front piston bracket and the rear piston bracket, and miniature Hall sensors are fixedly provided on the opposite side of the two sensor mounting brackets.

[0009] Preferably, both the front piston frame and the rear piston frame are equipped with a plurality of miniature temperature sensors, and the plurality of miniature temperature sensors are arranged at equal angles about the central axis of the front piston frame and the rear piston frame; the test ends of the plurality of miniature temperature sensors extend into the interior of the spiral guide groove, and the test ends of the plurality of miniature temperature sensors are in contact with the inner surface of the spiral guide frame.

[0010] Preferably, the sensor mounting brackets located on both sides of the front piston bracket and the rear piston bracket are provided with mounting grooves on their outer sides, and piezoelectric ceramic sheets are embedded inside the mounting grooves.

[0011] Preferably, a miniature receiving coil is also fitted on the outer peripheral surface of the magnetic core skeleton, and a high-frequency transmitting coil is wound inside the annular mounting groove and on one side of the front excitation coil and the rear excitation coil.

[0012] Preferably, a magnetic shielding layer is provided on the side of the high-frequency transmitting coil away from the infusion tube to confine the high-frequency magnetic field inside the infusion tube; the high-frequency transmitting coil is connected to an external high-frequency signal generator to generate a high-frequency alternating magnetic field inside the infusion tube.

[0013] Preferably, the spiral guide frame is integrally injection molded from medical-grade polyetheretherketone material; the spiral helix angle α of the spiral guide frame is 30° to 60°.

[0014] Preferably, the external Hall sensor array includes multiple sensing nodes spaced apart along the axial direction of the infusion tube, and at each sensing node, several Hall sensors are spaced apart at 90° or 120° along the circumference of the infusion tube.

[0015] Preferably, a miniature permanent magnet is embedded inside the sensor mounting bracket, and the miniature Hall sensor maintains a preset gap with the miniature permanent magnet, for detecting the relative position of the front piston bracket and the rear piston bracket relative to the inner wall of the infusion tube or detecting the polarity of the magnetic field generated by the external front excitation coil and the rear excitation coil.

[0016] Compared with existing technologies, it has the following advantages: 1. By incorporating a piston frame structure with spiral guide grooves inside the infusion tube, the hydrodynamic behavior of traditional plunger-type propulsion is altered. When the piston frame reciprocates, the medication forms a spiral jet under the guidance of the spiral guide grooves, forcing the fluid to rotate circumferentially. This effectively disrupts the static state of the tube wall boundary layer, converting axial thrust into swirling shear force. This not only reduces flow resistance but also eliminates the stagnation zone at the piston tip, achieving uniform delivery across the entire cross-section. This ensures that the medication remains dynamically mixed during delivery, preventing density stratification and precipitation. It is particularly suitable for infusing easily precipitated nutrient solutions such as fat emulsions and amino acids, significantly improving the stability and bioavailability of the infusion.

[0017] This invention employs a non-contact driving method that couples an excitation coil with a permanent magnet inside the piston. Combined with an integrated temperature sensor and piezoelectric ceramic element inside the piston, it achieves multi-functional integration. An external sequential current excitation generates a traveling wave magnetic field, driving the piston to reciprocate precisely. This avoids the intervention of mechanical transmission components, reducing wear and failure rates. At the same time, the hydrophilic coating on the piston surface and the spiral flow field work together to reduce shear stimulation to the vascular endothelium. Combined with the micro-vibrations generated by the piezoelectric ceramic, it can effectively inhibit bubble aggregation and thrombus adhesion, enhancing the anticoagulant performance of the device.

[0018] This invention utilizes a wireless power transmission structure composed of a high-frequency transmitting coil and a miniature receiving coil to achieve cable-free power supply for the internal circuitry of the piston. The high-frequency alternating magnetic field penetrates the pipe wall, inducing a current in the receiving coil inside the piston. After rectification and voltage regulation, the current continuously powers the sensors and actuators, completely avoiding the sealing failure and infection risks caused by wires penetrating the pipe wall. This not only ensures the stability of the piston's power supply during high-speed movement but also supports the long-term operation of real-time temperature feedback and ultrasound-assisted functions. This allows the device to autonomously perform constant temperature control and self-cleaning operations in a closed environment, improving the safety and convenience of clinical use.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a constant temperature and rate control device for deep vein catheterization infusion according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the infusion tube according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the infusion tube and external Hall sensor array structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the front piston frame and spiral guide frame structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the internal structure of the front piston holder in an embodiment of the present invention; Figure 6 This is a schematic diagram of the front piston holder and rear piston holder structure according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the miniature receiving coil and the high-frequency transmitting coil in an embodiment of the present invention.

[0021] In the diagram, 1. Infusion tube head; 2. Infusion tube; 3. Insulation sleeve; 4. Front piston holder; 5. Spiral guide groove; 6. Spiral guide frame; 7. Magnetic core skeleton; 8. Miniature temperature sensor; 9. Sensor mounting bracket; 10. Miniature Hall sensor; 11. Piezoelectric ceramic sheet; 12. Annular mounting groove; 13. External Hall sensor array; 14. Front excitation coil; 15. Rear piston holder; 16. Rear excitation coil; 17. Miniature receiving coil; 18. High-frequency transmitting coil. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0023] Please see Figures 1 to 7 As shown, a constant temperature and rate control device for deep vein catheterization infusion includes: an infusion catheter head 1 and an infusion tube 2. One side of the infusion catheter head 1 is fixedly connected to one end of the infusion tube 2, and the interior of the infusion tube 2 is connected to the interior of the infusion catheter head 1.

[0024] Specifically, a front piston holder 4 and a rear piston holder 15 are slidably provided on both sides inside the infusion tube 2, and a spiral guide groove 5 is provided on the surface of both the front piston holder 4 and the rear piston holder 15. A spiral guide frame 6 is fixedly provided on the surface of both spiral guide grooves 5. The outer peripheral surfaces of the front piston holder 4 and the rear piston holder 15 are in sealed sliding contact with the inner surface of the infusion tube 2, and the outer peripheral surfaces of both spiral guide frames 6 are in sealed sliding contact with the inner surface of the infusion tube 2. Among them, the outer peripheral surfaces of the front piston holder 4 and the rear piston holder 15 are provided with annular sealing grooves, and medical silicone O-rings are embedded in the sealing grooves. The wire diameter of the O-rings is compressed and the compression rate is controlled between 10% and 20% to ensure that when the spiral guide frame 6 slides in contact with the inner wall of the infusion tube 2, a fluid seal can be formed without jamming due to excessive friction.

[0025] The spiral guide frame 6 is integrally injection molded from medical-grade polyetheretherketone (PEEK) material. This material meets the ISO 10993 biocompatibility standard, can withstand the corrosion of various acid and alkali drugs during infusion, and does not produce particle shedding under long-term reciprocating friction, ensuring the safety of the drug solution. The spiral helix angle α of the spiral guide frame 6 is 30° to 60°. If the angle is less than 30°, the fluid rotation component is insufficient and cannot effectively eliminate the laminar flow dead zone; if the angle is greater than 60°, the fluid resistance increases sharply, resulting in a decrease in pumping efficiency. Preferably, in this embodiment, the spiral helix angle α is 45° to achieve the best balance between mixing effect and flow resistance.

[0026] Furthermore, in order to reduce fluid resistance and prevent thrombus or drug crystals from adhering, the surface roughness Ra of the spiral guide frame 6 is less than 0.4 μm, and the surface is coated with a hydrophilic lubricating coating. Preferably, the hydrophilic lubricating coating is a polydopamine coating.

[0027] The spiral groove depth of the spiral guide 6 is designed to be 1 / 10 to 1 / 5 of the inner radius of the infusion tube 2. When the liquid flows through the guide plate, it is forcibly divided into multiple spiral jets, thereby destroying the laminar boundary layer of the fluid and drawing the stagnant liquid that was originally near the inner wall of the infusion tube 2 into the central mainstream area, thereby improving the volumetric efficiency of the front piston frame 4 and the rear piston frame 15 during injection and the uniformity of drug mixing.

[0028] Specifically, the outer circumferential surface of the infusion tube 2 is provided with an annular mounting groove 12, and a front excitation coil 14 and a rear excitation coil 16 are respectively wound around the two sides of the outer circumferential surface of the annular mounting groove 12. A heat insulation sleeve 3 is fixedly provided on the outer circumferential surface of the annular mounting groove 12. The front excitation coil 14 and the rear excitation coil 16 are respectively used to drive the front piston frame 4 and the rear piston frame 15 to reciprocate inside the infusion tube 2. Several external Hall sensor arrays 13 are attached to the inner surface of the annular mounting groove 12 and inside the front excitation coil 14 and the rear excitation coil 16. The several external Hall sensor arrays 13 are distributed at equal angles about the central axis of the annular mounting groove 12. Sensor mounting brackets 9 are fixedly provided at both ends of the front piston frame 4 and the rear piston frame 15, and miniature Hall sensors 10 are fixedly provided on the opposite side of the two sensor mounting brackets 9.

[0029] The front excitation coil 14 and the rear excitation coil 16 adopt a multi-phase winding structure. The external controller supplies a timing current to the front excitation coil 14 and the rear excitation coil 16 to generate a traveling wave magnetic field that moves along the axial direction of the infusion tube 2. The permanent magnets embedded in the front piston frame 4 and the rear piston frame 15 interact with the traveling wave magnetic field to generate a Lorentz force, thereby driving the front piston frame 4 and the rear piston frame 15 to perform linear reciprocating motion along the axial direction. A magnetic core frame 7 is fixedly provided in the middle of the front excitation coil 14 and the rear excitation coil 16.

[0030] It should be noted that the surface of the miniature Hall sensor 10 is coated with an insulating and waterproof layer to prevent the drug solution from seeping in and causing a short circuit, and to ensure its electrical stability under long-term immersion conditions. A miniature permanent magnet is embedded inside the sensor mounting bracket 9. The miniature Hall sensor 10 maintains a preset small gap with this miniature permanent magnet, used to detect the relative position of the front piston holder 4 and the rear piston holder 15 relative to the inner wall of the infusion tube 2, or to detect the polarity of the magnetic field generated by the external front excitation coil 14 and the rear excitation coil 16. The external Hall sensor array 13 includes multiple sensing nodes spaced apart along the axial direction of the infusion tube 2. At each sensing node, several Hall sensors are spaced apart at 90° or 120° along the circumference of the infusion tube 2. This arrangement can eliminate the detection blind zone generated by the internal magnet of the piston during rotation or eccentric movement, ensuring that at least one external sensor can accurately capture the position signal regardless of the circumferential angle of the piston. The external Hall sensor array 13 is configured to detect the change in magnetic field strength when magnets pass by the front piston holder 4 and the rear piston holder 15. By detecting the order in which different sensors in the array are triggered, the control terminal can calculate the moving direction and real-time speed of the front piston holder 4 and the rear piston holder 15.

[0031] Furthermore, both the front piston holder 4 and the rear piston holder 15 are equipped with a number of miniature temperature sensors 8, and the miniature temperature sensors 8 are arranged at equal angles about the central axis of the front piston holder 4 and the rear piston holder 15; the test ends of the miniature temperature sensors 8 extend into the interior of the spiral guide groove 5, and the test ends of the miniature temperature sensors 8 are in contact with the inner surface of the spiral guide 6.

[0032] Among them, the miniature temperature sensor 8 is used to monitor the temperature of the medicine in the infusion tube 2 in real time. In addition, while driving the front excitation coil 14 and the rear excitation coil 16, a high-frequency micro-current can be passed through to generate Joule heat by utilizing copper loss. The heating power is controlled by the PID algorithm, thereby heating and keeping the medicine flowing through the infusion tube 2 at a constant temperature.

[0033] It should be noted that the spiral guide channel 5 forces the fluid to rotate, using centrifugal force to throw the high-speed fluid in the center towards the inner wall of the infusion pipe 2, disrupting the static boundary layer. This ensures that at the moment of transition when the front piston 4 stops and the rear piston 15 starts, the liquid in the entire cross-section of the infusion pipe 2 is in motion, eliminating the hysteresis effect of fluid initiation and ensuring a smooth transition of the flow curve. When the fluid flows through the spiral guide channel 5, it accumulates tangential kinetic energy. During the transition period, when the front piston 4 stops working, the rotational inertia of the fluid continues to maintain the mixing and forward transport trend of the liquid, effectively filling the instantaneous flow gap when the front piston 4 retracts. When the front piston 4 reverses and resets, the spiral guide channel 5 at its front end forms a spiral flow field. Compared with the direct axial negative pressure generated by the pullback of the flat-head piston, which is prone to backflow or cavitation, the spiral suction flow field converts the axial suction into tangential swirling flow, reducing the risk of backflow and allowing the fluid pushed out by the rear piston 15 to more smoothly replenish this area, maintaining the pressure stability of the main flow channel.

[0034] Furthermore, the sensor mounting brackets 9 located on both sides of the front piston bracket 4 and the rear piston bracket 15 are provided with mounting grooves on their outer sides, and piezoelectric ceramic sheets 11 are embedded inside the mounting grooves. To prevent the liquid from seeping in and to protect the piezoelectric ceramic sheets, the outer surface of the piezoelectric ceramic sheets 11 is covered with a flexible insulating and waterproof membrane. The outer surface of the flexible insulating and waterproof membrane is flush with the outer peripheral surface of the sensor mounting bracket 9, so as to ensure that when the front piston bracket 4 and the rear piston bracket 15 slide along the inner wall of the infusion tube 2, the piezoelectric ceramic sheets 11 will not directly rub against the tube wall of the infusion tube 2, thereby avoiding wear and ensuring sliding sealing. In addition, the electrodes of the piezoelectric ceramic sheets 11 are electrically connected to the signal processing circuit boards inside the front piston bracket 4 and the rear piston bracket 15 through shielded wires. The electrical signals generated by the piezoelectric ceramic sheets 11 are transmitted to the outside non-contactly through the wireless transceiver module or induction coil inside the front piston bracket 4 and the rear piston bracket 15, thereby avoiding the physical wires from getting tangled or broken during reciprocating motion.

[0035] It should also be explained that the mounting groove on the sensor mounting bracket 9 is located on the flat connecting surface between two adjacent spiral guide grooves 5, ensuring that the vibration surface of the piezoelectric ceramic plate 11 is not blocked by the side wall of the spiral structure when it performs high-frequency micro-amplitude vibration, thereby effectively transmitting ultrasonic vibration energy to the contacting liquid and the inner wall of the infusion tube 2. The piezoelectric ceramic plate 11 is configured as an ultrasonic vibration actuator. When the front piston frame 4 and the rear piston frame 15 are working, the external controller applies a high-frequency AC voltage to the piezoelectric ceramic plate 11, causing it to generate high-frequency micro-amplitude mechanical vibration. This high-frequency vibration is transmitted to the inner wall of the infusion tube 2 and the contacting liquid, which can break the boundary layer retention near the tube wall, prevent protein adsorption, and promote the aggregation or detachment of tiny bubbles in the liquid from the tube wall, preventing the risk of air embolism. By utilizing the ultrasonic lubrication effect, the dynamic friction coefficient between the front piston frame 4 and the rear piston frame 15 and the inner wall of the infusion tube 2 is reduced, improving the driving efficiency.

[0036] Specifically, in this embodiment, a front piston holder 4 and a rear piston holder 15 with a spiral guide groove 5 are set inside the infusion tube 2. These, along with the front excitation coil 14 and the rear excitation coil 16 within the annular mounting groove 12 and the external Hall sensor array 13, enable fluid monitoring of the infusion. A traveling wave magnetic field is generated by passing a sequential current through the front excitation coil 14 and the rear excitation coil 16, driving the permanent magnet inside the piston holder to reciprocate axially, thus achieving relay-push fluid delivery. The spiral guide holder 6 forms a sealed sliding contact with the inner wall of the infusion tube 2. Its spiral helix angle and the hydrophilic coating on its surface force the fluid to flow axially simultaneously... The device generates rotational shear, disrupting the laminar boundary layer at the tube wall and utilizing rotational inertia to eliminate the flow lag effect at the moment of piston junction. It not only achieves full-section shearing of the fluid through a spiral flow guiding structure, significantly reducing infusion pulsation and ensuring fluid continuity, but also uses a miniature temperature sensor 8 to directly contact the drug solution for real-time temperature measurement. Combined with the Joule heating effect of the front-end excitation coil 14 and the rear-end excitation coil 16, it achieves precise constant temperature control. At the same time, the ultrasonic vibration generated by the piezoelectric ceramic sheet 11 is transmitted to the drug solution through a flexible waterproof membrane, effectively preventing thrombus adhesion and bubble accumulation, and solving the problems of dead zones and lag in temperature control that are common in traditional infusion devices. Example 2

[0037] This embodiment is a further supplementary description of the scheme in the above embodiments. The outer peripheral surface of the magnetic core skeleton 7 is also fitted with a miniature receiving coil 17, and a high-frequency transmitting coil 18 is wound inside the annular mounting groove 12 and on one side of the front excitation coil 14 and the rear excitation coil 16.

[0038] To avoid interfering with the magnetic field distribution of the excitation coil, the high-frequency transmitting coil 18 adopts a flat spiral winding or multi-layer dense winding structure and is set close to the bottom wall of the annular mounting groove 12. An insulating isolation layer is provided between the high-frequency transmitting coil 18 and the front excitation coil 14 and the rear excitation coil 16. The insulating isolation layer is preferably a polyimide film to prevent short circuit between the high-voltage drive signal and the high-frequency signal.

[0039] Preferably, a magnetic shielding layer is provided on the side of the high-frequency transmitting coil 18 away from the infusion tube 2. The magnetic shielding layer is preferably a ferrite magnetic sheet, which is used to confine the high-frequency magnetic field inside the infusion tube 2 to prevent energy from being radiated outward and lost, and to prevent interference with external circuits. The high-frequency transmitting coil 18 is connected to an external high-frequency signal generator to form a high-frequency alternating magnetic field inside the infusion tube 2 as an energy transmitting end.

[0040] The miniature receiving coil 17 is embedded in the internal cavities of the front piston frame 4 and the rear piston frame 15, specifically in the non-magnetic areas of the front piston frame 4 and the rear piston frame 15. Considering the limited internal space of the piston frame, the miniature receiving coil 17 uses a high permeability magnetic core, preferably a nanocrystalline or ferrite magnetic rod, wound with enameled wire, or directly fabricated on the circuit board inside the front piston frame 4 and the rear piston frame 15 using PCB printing coil technology, so as to minimize the size while ensuring the inductance. The two ends of the miniature receiving coil 17 are electrically connected to the input terminals of the rectifier and voltage regulator circuit inside the front piston frame 4 and the rear piston frame 15. The output terminals of the rectifier and voltage regulator circuit are electrically connected to the miniature Hall sensor 10 and the piezoelectric ceramic sheet 11, respectively, thereby converting the sensed high-frequency AC power into DC power to power the sensor and actuator. The miniature receiving coil 17 is completely encapsulated in medical insulating potting compound, completely isolated from the drug solution, ensuring electrical insulation and biosafety in long-term immersion environments.

[0041] Furthermore, this embodiment employs frequency division multiplexing or time division multiplexing strategies for energy transmission and control: In the frequency division multiplexing mode, low-frequency high-current is supplied to the front-end excitation coil 14 and the rear-end excitation coil 16 to generate a strong magnetic field to drive the piston to reciprocate; while high-frequency low-current is supplied to the high-frequency transmitting coil 18. Due to the huge frequency difference, the miniature receiving coil 17 inside the front-end piston holder 4 and the rear-end piston holder 15 presents low impedance to the low-frequency driving magnetic field, which is equivalent to a short circuit or negligible, while generating resonant induction to the high-frequency magnetic field, thereby realizing wireless charging while the piston is moving, and the two do not interfere with each other; the energy is realized from the external power supply through the high-frequency transmitting coil 18, electromagnetic induction coupling, miniature receiving coil 17 and rectification and voltage regulation, and finally enters the interior of the miniature Hall sensor 10 and the piezoelectric ceramic sheet 11.

[0042] Specifically, this embodiment further utilizes a wireless energy transmission structure composed of a high-frequency transmitting coil 18 and a miniature receiving coil 17, based on the above. The high-frequency transmitting coil 18 within the annular mounting groove 12 is supplied with high-frequency alternating current to form an alternating magnetic field. This magnetic field penetrates the wall of the infusion tube 2 and couples to the miniature receiving coil 17 embedded within the front piston holder 4 and the rear piston holder 15. Through electromagnetic induction, energy is converted into high-frequency alternating current, which is then converted into direct current by an internal rectifier and voltage regulator circuit. This provides continuous power to the miniature Hall sensor 10, the piezoelectric ceramic plate 11, and other signal processing circuits. By employing a frequency division multiplexing strategy, the low-frequency driving magnetic field and the high-frequency energy magnetic field do not interfere with each other, achieving cableless energy supply during the piston's high-speed reciprocating motion. This completely avoids the risks of entanglement, breakage, and sealing failure associated with traditional wire connections. The miniature receiving coil 17 uses a high-permeability magnetic core or PCB printing technology, encapsulated with medical insulating potting compound, ensuring high-efficiency energy reception and long-term biosafety within a confined space. This provides reliable assurance for the stable operation of the intelligent sensor network inside the piston, greatly improving the device's integration and ease of clinical use. Example 3

[0043] Specifically, this embodiment discloses the working principle of a constant temperature and rate control device for deep vein catheterization infusion, including the following steps: Step 1: When the device is started, the external controller first activates the Hall sensor array 13 in the annular mounting groove 12. These sensors monitor the position signals of the magnets inside the front piston holder 4 and the rear piston holder 15 in real time. By analyzing the changes in magnetic field strength and the triggering sequence, the initial position and relative distance of the two piston holders in the infusion tube 2 are accurately determined.

[0044] Step 2: The controller supplies a multiphase current with a specific timing to the front excitation coil 14 according to the set infusion rate, thereby generating a moving traveling wave magnetic field in the infusion tube 2. This magnetic field interacts with the permanent magnet embedded in the front piston frame 4 to generate a Lorentz force, which drives the front piston frame 4 to move linearly back and forth along the inner wall of the infusion tube 2 toward the infusion insertion head, forcibly pushing the drug into the patient's body.

[0045] Step 3: During the advancement of the front piston frame 4 and the rear piston frame 15, the liquid is forced to flow through the spiral guide groove 5 and spiral guide frame 6 on the surface of the front piston frame 4 and the rear piston frame 15. Under the action of the spiral rise angle, the fluid is divided into multiple spiral jets and generates rotational motion. This rotation uses centrifugal force to destroy the laminar boundary layer near the pipe wall, and entrains the stagnant liquid into the mainstream area, which not only eliminates the fluid dead zone, but also improves the uniformity of liquid mixing.

[0046] Step 4: When the front piston holder 4 moves to the end of its stroke, the controller immediately starts the rear excitation coil 16 to drive the rear piston holder 15 to begin the forward stroke. At this time, the front piston holder 4 stops doing work and begins to reset. Relying on the tangential rotational inertia accumulated in the spiral guide channel 5, the pressure in the main channel is kept stable, effectively filling the flow gap at the moment of piston handover and eliminating the hysteresis effect of fluid start-up.

[0047] Step 5: The miniature temperature sensor 8 embedded inside the piston frame detects the temperature of the liquid medicine flowing through the spiral guide frame 6 in real time and feeds the data back to the external control terminal. The controller compares the difference between the set temperature and the actual temperature through the PID algorithm and dynamically adjusts the magnitude of the high-frequency micro-current supplied to the front excitation coil 14 and the rear excitation coil 16. The Joule heat generated by the copper loss of the coil is used to heat the infusion tube 2, thereby achieving precise constant temperature infusion of the liquid medicine.

[0048] Step 6: To maintain the operation of the electronic components inside the piston, the high-frequency transmitting coil 18 continuously emits a high-frequency alternating magnetic field. This magnetic field penetrates the tube wall and is captured by the miniature receiving coil 17 inside the piston holder. An induced current is generated through the principle of electromagnetic induction. After being converted into DC power by the rectifier and voltage regulator circuit, it provides a continuous working power supply for the miniature Hall sensor 10, the piezoelectric ceramic sheet 11 and the signal processing circuit, realizing cableless energy transmission.

[0049] Step 7: The controller applies a high-frequency AC voltage to the piezoelectric ceramic sheet 11 on the front piston holder 4 and the rear piston holder 15, causing it to generate high-frequency micro-amplitude mechanical vibration. This vibration is transmitted to the liquid medicine and the tube wall through the flexible insulating waterproof membrane. The cavitation effect of the ultrasonic wave and the vibration disturbance destroy the protein adsorption layer that may be formed, causing the micro bubbles to coalesce or detach from the tube wall. At the same time, it reduces the dynamic friction coefficient between the piston and the tube wall, improves the driving efficiency, and prevents the risk of air embolism.

[0050] Step 8: After the front piston holder 4 completes the injection stroke, it returns to its original position along the infusion tube 2 under the drive of the magnetic field. At this time, its spiral structure forms a spiral flow field, which converts the axial suction force into a tangential swirling flow to reduce the risk of backflow. The two piston holders alternately perform injection and reset movements under the coordination of the controller. With the real-time feedback of the sensor array, a closed-loop control is formed until the predetermined total infusion volume is completed or the set time period is reached.

[0051] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0052] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A constant temperature and rate control device for deep vein catheterization infusion, comprising an infusion catheter head (1) and an infusion tube (2), wherein one side of the infusion catheter head (1) is fixedly connected to one end of the infusion tube (2), and the interior of the infusion tube (2) is in communication with the interior of the infusion catheter head (1), characterized in that, The infusion tube (2) has a front piston frame (4) and a rear piston frame (15) slidably mounted on both sides inside. The surfaces of the front piston frame (4) and the rear piston frame (15) are provided with spiral guide grooves (5), and the surfaces of the two spiral guide grooves (5) are fixedly provided with spiral guide frames (6). The outer circumferential surface of the infusion tube (2) is provided with an annular mounting groove (12), and the two sides of the outer circumferential surface of the annular mounting groove (12) are respectively wound with a front excitation coil (14) and a rear excitation coil (16). The front excitation coil (14) and the rear excitation coil (16) are respectively used to drive the front piston frame (4) and the rear piston frame (15) to reciprocate inside the infusion tube (2). The middle part of the front excitation coil (14) and the rear excitation coil (16) is fixedly provided with a magnetic core skeleton (7).

2. The constant temperature and rate control device for deep vein catheterization infusion according to claim 1, characterized in that, The outer circumferential surfaces of the front piston frame (4) and the rear piston frame (15) are provided with annular sealing grooves, and medical silicone O-rings are embedded in the sealing grooves; the outer circumferential surface of the annular mounting groove (12) is fixedly provided with a heat insulation sleeve (3).

3. The constant temperature and rate control device for deep vein catheterization infusion according to claim 1, characterized in that, Several external Hall sensor arrays (13) are attached to the inner surface of the annular mounting groove (12) and inside the front excitation coil (14) and the rear excitation coil (16). The several external Hall sensor arrays (13) are arranged at equal angles about the central axis of the annular mounting groove (12). Sensor mounting brackets (9) are fixed at both ends of the front piston bracket (4) and the rear piston bracket (15), and miniature Hall sensors (10) are fixed on the opposite side of the two sensor mounting brackets (9).

4. The constant temperature and rate control device for deep vein catheterization infusion according to claim 1, characterized in that, The front piston frame (4) and the rear piston frame (15) are each equipped with a number of miniature temperature sensors (8), and the miniature temperature sensors (8) are arranged at equal angles about the central axis of the front piston frame (4) and the rear piston frame (15); the test ends of the miniature temperature sensors (8) extend into the interior of the spiral guide groove (5), and the test ends of the miniature temperature sensors (8) are in contact with the inner surface of the spiral guide frame (6).

5. The constant temperature and rate control device for deep vein catheterization infusion according to claim 1, characterized in that, The sensor mounting brackets (9) located on both sides of the front piston bracket (4) and the rear piston bracket (15) are provided with mounting grooves on the outside, and piezoelectric ceramic sheets (11) are embedded inside the mounting grooves.

6. The constant temperature and rate control device for deep vein catheterization infusion according to claim 1, characterized in that, The outer periphery of the magnetic core skeleton (7) is also fitted with a miniature receiving coil (17), and a high-frequency transmitting coil (18) is wound inside the annular mounting groove (12) and on one side of the front excitation coil (14) and the rear excitation coil (16).

7. The constant temperature and rate control device for deep vein catheterization infusion according to claim 6, characterized in that, A magnetic shielding layer is provided on the side of the high-frequency transmitting coil (18) away from the infusion tube (2) to confine the high-frequency magnetic field inside the infusion tube (2); the high-frequency transmitting coil (18) is connected to an external high-frequency signal generator to form a high-frequency alternating magnetic field inside the infusion tube (2).

8. The constant temperature and rate control device for deep vein catheterization infusion according to claim 1, characterized in that, The spiral guide frame (6) is integrally injection molded from medical-grade polyether ether ketone material; the spiral helix angle α of the spiral guide frame (6) is 30° to 60°.

9. The constant temperature and rate control device for deep vein catheterization infusion according to claim 3, characterized in that, The external Hall sensor array (13) includes multiple sensing nodes spaced apart along the axial direction of the infusion tube (2). At each sensing node, several Hall sensors are spaced apart at 90° or 120° along the circumference of the infusion tube (2).

10. A constant temperature and rate control device for deep vein catheterization infusion according to claim 3, characterized in that, A miniature permanent magnet is embedded inside the sensor mounting bracket (9). The miniature Hall sensor (10) and the miniature permanent magnet maintain a preset gap setting to detect the relative position of the front piston bracket (4) and the rear piston bracket (15) relative to the inner wall of the infusion tube (2) or to detect the polarity of the magnetic field generated by the external front excitation coil (14) and the rear excitation coil (16).

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