Targeted drug delivery device with catheter pose monitoring function

Abstract

The utility model relates to the technical field of minimally invasive medical instruments, and discloses a targeted drug delivery device with catheter pose monitoring, which comprises a drug delivery catheter and a monitoring mechanism, the monitoring mechanism is used for monitoring the pose of the drug delivery catheter, the drug delivery catheter is internally provided with a drug delivery channel, a mixing cavity and a passing channel for a guide wire to pass through, the mixing cavity is located at the far end of the dosing catheter, the dosing channel is spirally distributed and communicated with the mixing cavity, and a medicine outlet communicated with the mixing cavity is formed in the outer side of the far end of the dosing catheter; the monitoring mechanism comprises an excitation assembly and a sensor ring, the sensor ring capable of moving back and forth through the monitoring mechanism can obtain the three-dimensional position and attitude information of the catheter in real time, high-precision real-time positioning and attitude monitoring are achieved, the limitation of traditional X-ray intermittent imaging is eliminated, repeated perspective adjustment of the position of the catheter is not needed, surgical operation is greatly simplified, and operation efficiency is improved. And the operation difficulty and radiation exposure of doctors and patients are reduced.

Description

Technical Field

[0001] This utility model relates to the field of minimally invasive medical device technology, specifically to a targeted drug delivery device with catheter position monitoring. Background Technology

[0002] Currently, clinical intravascular local drug delivery techniques are mainly divided into two categories: traditional direct injection and catheter-based drug delivery systems. Traditional direct injection involves manually pushing the drug into the target vascular area through a catheter. The drug relies on natural dilution and passive diffusion by blood flow to reach the lesion. This method has drawbacks such as short local drug retention time, low utilization rate, uneven distribution in the lesion area, and poor precision in controlling the dosage and rate of manual injection, which can easily lead to insufficient local efficacy and increased risk of systemic toxicity.

[0003] Existing catheter-based drug delivery systems, including end-hole infusion catheters, side-hole infusion catheters, and balloon drug delivery catheters, while optimizing drug coverage to some extent, still have many shortcomings:

[0004] (1) The flow channel lacks fluid dynamics optimization design, and the liquid is prone to backflow and leakage, which poses a safety hazard;

[0005] (2) Drug release is still a passive outflow mode, which cannot actively form turbulence to disrupt the laminar flow boundary of blood flow, resulting in low efficiency of drug mixing and penetration with lesion tissue and thrombus;

[0006] (3) The catheter has a single function and does not integrate posture and position monitoring functions. The drug delivery operation relies entirely on X-ray imaging for positioning, which not only increases radiation exposure and operational complexity, but also makes it impossible to achieve precise drug delivery. The drug delivery and positioning systems are separate and difficult to coordinate.

[0007] Furthermore, existing targeted drug delivery technologies mostly optimize the drug delivery location by adding external mechanical structures. For example, Chinese patent application number 2025118420405 proposes a targeted thrombolytic drug delivery device for ischemic cerebrovascular disease using traditional Chinese medicine. This device includes a catheter body, an inner tube, a drug delivery nozzle, a drug flow channel, and a displacement mechanism located at the distal end of the catheter body. The inner wall of the inner tube has a passageway for the guidewire to pass through. The displacement mechanism includes two sets of balloon groups distributed at both ends of the drug delivery nozzle. Each set of balloons includes at least four anchoring balloons arranged in a ring array along the outer wall of the catheter body. The four anchoring balloons in a single set are independently distributed. This drug delivery device, through active control, ensures that the drug delivery nozzle is always directly facing the area where the thrombus is most concentrated, avoiding drug waste and unnecessary erosion of the blood vessel wall, and greatly improving the utilization efficiency and thrombolytic speed of traditional Chinese medicine. However, it has drawbacks such as large catheter outer diameter, poor blood vessel permeability, cumbersome operation, and easy damage to blood vessel walls. Furthermore, it does not fundamentally solve the fluid control problems of dilution, reflux, and uneven mixing after the drug flows out.

[0008] In summary, existing intravascular targeted drug delivery technologies generally suffer from common bottlenecks such as passive and inefficient fluid control, disconnect between drug delivery and positioning sensing, and lack of systematic optimization in structural design. These bottlenecks result in low drug utilization, high risk of side effects, reliance on experience in operation, and limited drug delivery accuracy in clinical applications, making it difficult to meet the needs of precise interventional therapy in clinical practice. Utility Model Content

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a targeted drug delivery device with catheter posture monitoring. By optimizing the internal fluid structure of the drug delivery catheter to enhance the local retention and mixing efficiency of the drug, and integrating posture sensing to achieve precise navigation and evaluation, the therapeutic efficacy and operational intelligence level of intravascular local targeted drug delivery are improved.

[0010] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0011] A targeted drug delivery device with catheter position monitoring includes a drug delivery catheter and a monitoring mechanism. The drug delivery catheter passes through the monitoring mechanism, which is used to monitor the position of the drug delivery catheter. The drug delivery catheter has a drug delivery channel, a mixing chamber, and a passage channel for a guidewire to pass through inside. The mixing chamber is located at the distal end of the drug delivery catheter and is sleeved on the outside of the passage channel. The drug delivery channel is spirally distributed around the axis of the passage channel and communicates with the mixing chamber. A drug outlet is provided on the outer side of the distal end of the drug delivery catheter, which communicates with the mixing chamber.

[0012] The monitoring mechanism includes an excitation component, a sensor ring, and a drive component for driving the sensor ring to move linearly in the front-back direction. When the excitation component is energized, it generates an alternating magnetic field. The drug delivery catheter passes through the excitation component and the sensor ring in sequence, and the sensor ring is used to detect the magnetic induction intensity vector of the guidewire in the magnetic field.

[0013] Optionally, the sensor ring includes an annular frame that can move in the front-back direction, with a through hole at the center of the annular frame for the passage of the drug delivery catheter, and multiple three-dimensional magnetic sensors disposed on the annular frame.

[0014] Optionally, the monitoring mechanism further includes a support frame on which two drive components are disposed opposite each other, the annular frame is located between the two drive components, and the excitation component is connected to the support frame.

[0015] Optionally, the drive assembly includes a support column and a drive motor arranged opposite each other in the front-rear direction. A drive wheel is installed at the output end of the drive motor, and a driven wheel is rotatably installed on the support column. A timing belt is fitted on the drive wheel and the driven wheel, and the inner edge of the timing belt is fixedly connected to the annular frame.

[0016] Optionally, the mixing chamber is a rotating ellipsoidal structure, and the inner wall of the mixing chamber is provided with multiple protrusions, which are hemispherical in shape and distributed at intervals along the axial direction of the drug delivery catheter.

[0017] Optionally, the drug delivery channel is provided with three channels, all of which are arranged in a spiral pattern in parallel around the axis of the passage channel.

[0018] Optionally, the three-dimensional magnetic sensor is provided in six parts, and the six three-dimensional magnetic sensors are arranged in a circular array around the axis of the through hole.

[0019] Optionally, the proximal end of the drug delivery catheter is connected to a drive pump, the output end of the drive pump is connected to the drug delivery channel, and the distal end of the guidewire is connected to a permanent magnet.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] (1) In this utility model, the sensor ring that can move back and forth through the monitoring mechanism can acquire the three-dimensional position and attitude information of the catheter in real time, realize high-precision real-time positioning and attitude monitoring, get rid of the limitations of traditional intermittent X-ray imaging, and eliminate the need to repeatedly fluoroscopy to adjust the position of the catheter, greatly simplifying the surgical operation and reducing the difficulty of operation and radiation exposure of both doctors and patients.

[0022] (2) In this utility model, by designing an anti-backflow spiral drug delivery channel and a turbulent mixing chamber, the drug backflow rate can be significantly reduced, the effective action time of the drug in the lesion area can be significantly extended, and the drug mixing efficiency and turbulence intensity can be significantly improved, so as to achieve precise locking and uniform distribution of the drug in the target area. The dosage can be reduced under the same therapeutic effect, and the risk of systemic toxic side effects can be reduced.

[0023] (3) In this utility model, the internal flow channel of the drug delivery catheter is optimized and combined with micro-sensor integration, which can not significantly increase the outer diameter of the drug delivery catheter, fully ensuring the passage and flexibility of the catheter in blood vessels. At the same time, a passive fluid optimization design is adopted, such as setting protrusions and spiral drug delivery channels in the mixing cavity, eliminating the need for balloon mechanical operation, avoiding the potential risk of vascular mechanical damage, and improving treatment safety. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the targeted drug delivery device with catheter position monitoring in an embodiment of this utility model;

[0025] Figure 2 This is a perspective view of the drug delivery catheter in an embodiment of this utility model;

[0026] Figure 3 This is a schematic diagram of the internal structure of the drug delivery catheter in an embodiment of this utility model;

[0027] Figure 4 This is a schematic diagram of the position and structure of the drug delivery channel in an embodiment of this utility model;

[0028] Figure 5 This is a schematic diagram of the excitation assembly in an embodiment of this utility model;

[0029] Among them, 1 is the drug delivery catheter; 101 is the passageway; 102 is the drug delivery channel; 103 is the mixing chamber; 104 is the drug outlet; and 105 is the protrusion.

[0030] 2. Ring-shaped frame; 3. Three-dimensional magnetic sensor;

[0031] 4. Excitation assembly; 401. Support; 402. Coil;

[0032] 5. Support frame; 6. Drive motor; 7. Drive wheel; 8. Support column; 9. Driven wheel; 10. Synchronous belt. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0034] Example 1, such as Figures 1-5 As shown, a targeted drug delivery device with catheter posture monitoring includes a drug delivery catheter 1 and a monitoring mechanism. The drug delivery catheter 1 passes through the monitoring mechanism, which is used to monitor the posture of the drug delivery catheter 1. The drug delivery catheter 1 is used for targeted drug delivery within blood vessels. The distal end refers to the end of the catheter that extends into the body cavity during drug delivery, and the proximal end refers to the end of the catheter that is opposite to the distal end during drug delivery. The targeted drug delivery device proposed in this application has a catheter posture monitoring function. By optimizing the internal fluid structure of the drug delivery catheter 1 to enhance the local retention and mixing efficiency of the drug, and integrating real-time posture perception to achieve precise navigation and evaluation, the therapeutic efficacy and operational intelligence level of intravascular local targeted drug delivery are improved.

[0035] like Figures 2-4As shown, the inside of the drug delivery catheter 1 is provided with a drug delivery channel 102, a mixing chamber 103, and a passage channel 101 for the guide wire to pass through. The mixing chamber 103 is located at the distal end of the drug delivery catheter 1 and is sleeved on the outside of the passage channel 101. The drug delivery channel 102 is spirally distributed around the axis of the passage channel 101 and communicates with the mixing chamber 103. The outer side of the distal end of the drug delivery catheter 1 is provided with a drug outlet 104 communicating with the mixing chamber 103.

[0036] The proximal end of the drug delivery catheter 1 is connected to a drive pump, the output end of which is connected to the drug delivery channel 102. The distal end of the guidewire is connected to a permanent magnet. There are three drug delivery channels 102, which are all arranged in parallel spirally around the axis of the through channel 101. The inner wall of the mixing chamber 103 is provided with multiple protrusions 105, which are hemispherical in shape and distributed at intervals along the axial direction of the drug delivery catheter 1.

[0037] Specifically, the internal structure of the drug delivery catheter 1 is a special flow channel and cavity structure optimized by fluid dynamics calculations, used for precise drug release and efficient mixing. That is, the drug is pressurized by the drive pump at the proximal end of the drug delivery and flows into the mixing chamber 103 through three helical drug delivery channels 102. Turbulence is formed in the mixing chamber 103 and it is delivered to the lesion area through the drug outlet 104.

[0038] As described above, the drug delivery channel 102 is a spirally ascending, slender flow channel set inside the wall of the drug delivery catheter 1. This design is based on the Dean Flow principle. In the spiral channel, the fluid is subjected to centrifugal force, generating paired secondary vortices (i.e., Dean vortices) perpendicular to the mainstream direction. By selecting an appropriate spiral angle α, stable Dean vortices can be generated. Their function is to: effectively resist the reverse hydrostatic pressure and blood flow scouring from the venous end, significantly inhibiting drug backflow; and enhance radial mixing within the flow channel, pre-treating the drug before it enters the terminal mixing chamber 103.

[0039] The design is based on the Dean number (De) within the flow channel, calculated for the target blood vessel and the preset drug infusion rate. The Dean number reflects the ratio of centrifugal force to viscous force in the helical flow channel, and its expression is:

[0040]

[0041] Where Re is the liquid Reynolds number (Re = 2ρvR) h / μ, where ρ is the fluid density, μ is the fluid viscosity, and v is the axial velocity of the liquid), R h R is the hydraulic radius of the helical tube. C Let be the radius of the spiral.

[0042] The mixing chamber 103 is located at the end of the drug delivery channel 102 and is a rotating ellipsoid with a central perforation. The axial radius (a) and radial radius (b) of the ellipsoid can maximize the curvature change and area change of the flow inside the chamber to promote turbulence. On the inner wall surface of the ellipsoidal mixing chamber 103, there is an array of tiny geometric protrusions 105 that are regularly or irregularly distributed in the circumferential and axial directions.

[0043] Specifically, the drug enters the suddenly expanding ellipsoidal cavity from the narrow helical tube, causing a drastic change in area. According to Bernoulli's principle, this leads to a sharp drop in flow velocity and a steep increase in pressure, forming a strong adverse pressure gradient. The adverse pressure gradient is the fluid dynamics mechanism that induces macroscopic flow separation, making it easy for the mainstream fluid to detach from the cavity wall, forming large-scale reflux zones and vortices.

[0044] To maximize the rate of change of curvature and the rate of change of area of ​​the flow field within the cavity, the profile of the mixing cavity 103 is not a standard ellipse, but rather a high-curvature region that is naturally formed at specific axial positions (such as the front 1 / 3 and the rear 1 / 3). In the high-curvature region, the fluid tends to deviate from the curved streamlines due to inertia, which exacerbates the instability of the flow and promotes the generation of secondary flows and vortices.

[0045] Meanwhile, the array of protrusions 105 on the inner wall acts as a turbulence generator, actively disturbing the laminar boundary layer near the wall. When fluid flows through these protrusions 105, local flow separation occurs, forming tiny, unstable vortices downstream of each protrusion 105. The geometry of the front of the mixing chamber 103 facilitates the formation of a relatively stable, low-velocity reflux zone, where some drug molecules can circulate and remain, effectively prolonging the local action time. Finally, the fully turbulently mixed drug solution is uniformly released from the array of drug outlets 104.

[0046] like Figure 1 As shown, the monitoring mechanism includes a support 5, an excitation assembly 4, a sensor ring, and a drive assembly for driving the sensor ring to move linearly in the front-back direction. When the excitation assembly 4 is energized, it generates an alternating magnetic field. The drug delivery catheter 1 passes through the excitation assembly 4 and the sensor ring sequentially, and the sensor ring is used to detect the magnetic induction intensity vector experienced by the guidewire in the magnetic field. Using a magnetic dipole positioning algorithm, combined with the multi-angle observation advantage brought by the movement of the sensor ring, high-precision real-time solution of the three-dimensional spatial position and attitude of the guidewire / drug delivery catheter 1 is achieved. The three-dimensional structure of the target is then inferred from the projection data from multiple angles.

[0047] The sensor ring includes an annular frame 2 (O-shaped rigid) that can move in the front-back direction. A through-hole for the drug delivery catheter 1 to pass through is provided at the center of the annular frame 2. Six three-dimensional magnetic sensors 3 are mounted on the annular frame 2, and the six three-dimensional magnetic sensors 3 are arranged in a circular array around the axis of the through-hole. That is, the annular frame 2 surrounds the guidewire or drug delivery catheter 1, with the array of three-dimensional magnetic sensors 3 mounted on its inner side and connected to the drive assembly on its outer side. It collects the magnetic induction intensity vector (Bx, By, Bz) experienced by the guidewire / drug delivery catheter 1 in the magnetic field in real time and converts it into an electrical signal output.

[0048] Specifically, the end of the guide wire has a permanent magnet for positioning. When the excitation component 4 is energized, it generates an alternating magnetic field. The guide wire passes through this magnetic field and generates eddy currents, thereby exciting the magnetic field and making the guide wire magnetic. The position detection uses a magnetic sensor, which simply means measuring the magnetic field and then deriving the positioning based on the formula.

[0049] Two drive components are arranged opposite each other on the bracket 5, the annular frame 2 is located between the two drive components, and the excitation component 4 is connected to the bracket 5. The drive component includes a support column 8 and a drive motor 6 arranged opposite each other in the front-back direction. A drive wheel 7 is installed at the output end of the drive motor 6, and a driven wheel 9 is rotatably installed on the support column 8. A synchronous belt 10 is sleeved on the drive wheel 7 and the driven wheel 9. The inner edge of the synchronous belt 10 is fixedly connected to the annular frame 2, and the synchronous belt 10 is parallel to the front-back direction.

[0050] The excitation assembly 4 is located on one side or above the sensor ring, including a support 401 and a coil 402 mounted on the support 401. It has a hole in the center for the guide wire / drug delivery catheter 1 to pass through, and can generate a stable and uniform alternating magnetic field when energized.

[0051] The drive motor 6 is a servo motor, connected to the ring frame 2 via a transmission mechanism. It drives the sensor ring to move in a stepping or continuous manner along the axial direction of the guidewire / drug delivery catheter 1 to adapt to guidewire or drug delivery catheter 1 segments of different lengths, ensuring that the three-dimensional magnetic sensor 3 is always located near the target monitoring area. The synchronous belt 10 is a high-rigidity, low-elongation toothed synchronous belt 10. Both the driving pulley 7 and the driven pulley 9 are synchronous pulleys, which together with the synchronous belt 10 form a belt drive structure to transmit the motion of the servo motor, ensuring the transmission accuracy and synchronization of the sensor ring during movement and preventing slippage or misalignment.

[0052] The specific workflow is as follows:

[0053] (1) First, consider a small permanent magnet at the end or tip of the guide wire as a magnetic dipole. According to the theory of physics, the magnetic field strength generated by the magnetic dipole at any point in space is inversely proportional to the cube of the distance from that point to the magnetic dipole, and is related to the magnetic moment and relative orientation of the magnetic dipole.

[0054] (2) During operation, the drive component drives the sensor ring to move back and forth in a straight line. During this process, the six three-dimensional magnetic sensors 3 installed on the ring frame 2 will collect the three-dimensional magnetic induction intensity vector (Bx, By, Bz) generated by the magnetic dipole in real time. The three-dimensional magnetic sensors 3 collect multi-angle magnetic field data about the target magnetic source (magnetic dipole) while moving.

[0055] (3) Data reconstruction process: Let the actual position of the magnetic dipole be (x, y, z), and the position of the three-dimensional magnetic sensor 3 relative to the support 5 be (x, y, z). i y i , z i For each sensor position i, based on the measured magnetic field strength B i A nonlinear system of equations about (x, y, z) can be established based on the magnetic dipole formula;

[0056] Since the sensor ring has moved to multiple positions relative to the support 5, N sets of the above equations can be obtained. By using the closed-form formula method, the ambiguity of traditional single-point measurement can be eliminated by solving these N sets of equations simultaneously, and the three-dimensional spatial coordinates (x, y, z) of the magnetic dipole (i.e., guidewire / drug delivery catheter 1) can be uniquely and accurately deduced.

[0057] Similarly, by observing the directional changes of the magnetic field vector in space (magnetic gradient tensor), the three-dimensional attitude of the guidewire (such as pitch angle, yaw angle, and roll angle) can be further calculated. Compared with traditional single-point magnetic positioning algorithms, which often suffer from non-unique solutions (i.e., multiple locations may produce the same magnetic field reading) or insufficient accuracy, the moving sensor ring introduced in this application provides motion parallax and acquires projection data from multiple angles.

[0058] Example 2: Based on Example 1, the present invention proposes the following implementation method.

[0059] (1) Target Environment and Clinical Background: Fluid data refer to the recommendations for pH and osmolarity of the drug solution given by the American Society for Infusion Nursing: Injection site: cephalic vein and internal brachial vein of the upper arm, blood flow rate 40-95 mL / min, osmolarity <500 mOsm / L, solution pH 3-9; Target vessel: cephalic vein of the upper arm, diameter approximately 3-6 mm; Clinical problem: venous thrombosis at this site, requiring local thrombolytic therapy; Blood flow conditions: blood flow rate range 40-95 mL / min (average 68 mL / min), blood flow velocity approximately 0.1 m / s, venous pressure approximately 5-10 mmHg; Target drug: tissue plasminogen activator, infusion rate set at 5 mL / min. The physical properties of the drug solution are similar to water: density 1000 kg / m3, dynamic viscosity 1.0 mPa·s, pH=7.0, osmolarity 400 mOsm / L.

[0060] (2) The drug delivery catheter 1 is a 9F (French) catheter with an outer diameter (OD) of 3.0 mm and an inner diameter (ID) of 1.0 mm, providing a guidewire passage 101; three parallel spiral drug delivery channels 102 are provided inside the wall of the drug delivery catheter 1, evenly distributed around the circumference of the drug delivery catheter 1, and each spiral drug delivery channel 102 has a corresponding outlet, with a hydraulic diameter D h =0.6mm, with a circular cross-section and an area of ​​0.28mm². 2 Spiral radius (helix radius) R C =0.1mm, helix angle α = 12°.

[0061] Axial flow velocity: v = 5 (mL / min) / (3 × 0.28 (mm) 2 ))≈5.95cm / s.

[0062] Reynolds number: Re = ρ × v × D h / μ≈1000 × 0.0595 × 0.0006 / 0.001 = 35.7 (laminar flow).

[0063] Dean's number: When De is greater than 40, a stable Dean vortex pair can be formed. In this design, De > 60, indicating that a stable and strong Dean vortex secondary flow can be generated, which is sufficient to produce a radial pressure field that resists the reverse pressure of the vein.

[0064] The turbulence-enhanced mixing chamber 103 has an axial radius (major axis) of a = 1.9 mm and a radial radius (minor axis) of b = 1.6 mm. The aspect ratio L / D = 3.8 / 3.2 = 1.19, which is near the optimal range (1.2-1.8). After fine-tuning, it has good mixing potential.

[0065] Turbulence generator: An array of hemispherical micro-protrusions 105 is arranged on the inner wall of the mixing chamber 103. The height h of the protrusions 105 is 0.15 mm, and the bottom diameter d is 0.25 mm. They are arranged non-uniformly, with higher density in the first 1 / 3 of the chamber (high velocity region) and at the maximum diameter (high curvature region) to induce boundary layer transition and local vortices in advance.

[0066] Drug outlet array: At the end of the mixing chamber 103, three circular drug outlet holes 104 are evenly distributed along the circumference at 120°, each hole having a diameter of 0.5 mm, corresponding to the outlet of the drug delivery channel 102.

[0067] Drive pump: A high-precision injection pump is used to simultaneously pump rt-PA solution into three drug delivery channels 102 at a constant flow rate of 5.0±0.1mL / min.

[0068] (3) Sensor ring: A rigid O-ring with an inner diameter of 35cm is used, with 6 triaxial digital Hall effect sensors (model: LIS3MDL) evenly distributed around it. The drive motor 6 uses a NEMA8 stepper motor, paired with a GT2 toothed synchronous belt 10; Controller: An integrated STM32 microcontroller is used for motor control, sensor data acquisition (sampling rate 100Hz) and preliminary data filtering; Excitation component 4: Three Helmholtz coils 402 are used, with an AC current of 1kHz and 100mA applied to generate a uniform alternating magnetic field of about 1mT in the central region. Magnetic marker: A neodymium iron boron cylindrical permanent magnet with a diameter of 0.3mm and a length of 1.0mm is embedded at the tip of the guide wire with a diameter of 0.36mm, and its magnetic moment direction is along the guide wire axis.

[0069] (4) Work process:

[0070] S1. Pass the guidewire with magnetic marker through the passage channel 101 of the drug delivery catheter 1, fix the drug delivery catheter 1 to the support 5, ensure that the drug delivery catheter 1 and the support 5 are parallel, turn on the excitation assembly 4 and the sensor ring, collect and store the background magnetic field data in the state without the guidewire; place the tip of the guidewire at the known position of the center of the sensor ring, perform system calibration, and establish a precise mapping relationship between the magnetic field reading and the spatial position.

[0071] S2. Under ultrasound guidance, the guidewire is percutaneously inserted into the cephalic vein of the upper arm and advanced towards the thrombus site. The continuous scanning mode of the monitoring mechanism is activated, i.e., the stepper motor drives the sensor ring to reciprocate at a speed of 10 mm / s, and the microcontroller collects the magnetic field vector B measured by 6 sensors at multiple locations (N>20) in real time. i The closed-formula method (CFM) based on the magnetic dipole model is used for real-time solution. The algorithm input consists of N sets (B xi B yi B zi x si y si , z si The output is the real-time six-dimensional attitude of the permanent magnet at the guidewire tip: position (x, y, z) and attitude angle (θ, ϕ, ψ). The solution is displayed in real time on the operating room monitor as a 3D model superimposed on the preoperative CT angiography image. The surgeon can clearly see whether the guidewire tip has reached the proximal end of the thrombus and its relative angle with the vessel wall.

[0072] S3. When the monitor shows that the guidewire tip has accurately reached the thrombus site and the long axis of the catheter is approximately parallel to the blood vessel, the positioning is confirmed to be complete. Connect the infusion pump equipped with rt-PA and set the infusion rate to 5 mL / min. Start the infusion pump, and the medication enters the turbulence-enhanced mixing chamber 103 through three anti-backflow spiral-shaped drug delivery channels 102. The monitoring device continues to operate during drug delivery. If the position of the drug delivery catheter 1 tip deviates beyond the preset threshold due to blood flow impact or patient movement, the system will issue an audible and visual alarm, prompting the doctor to pause drug delivery and readjust the position.

[0073] Example 3: Based on the above examples, computational fluid dynamics simulation and in vitro simulation experiments were conducted to verify the effectiveness of this invention.

[0074] (1) CFD simulation results:

[0075] Backflow inhibition: Under simulated venous blood flow conditions (flow velocity 0.1 m / s, reverse pressure 8 mmHg), the drug backflow rate of conventional side-hole catheters is as high as 45%. However, after adopting the anti-backflow spiral tube design of this invention, simulations show that the backflow rate is reduced to 7%, consistent with the aforementioned reduction of 85-90%.

[0076] Mixing efficiency: A virtual "drug tracer" is placed within the mixing chamber 103. The rate at which its variance (characterizing uniformity) decays over time is calculated. The mixing chamber 103 (including protrusion 105) designed in this invention achieves 95% mixing uniformity in 68% less time than a simple cylindrical cavity of the same volume, demonstrating a significant improvement in mixing efficiency.

[0077] Turbulence intensity: In the mixing cavity 103 region, the turbulence intensity designed in this invention is maintained at 15%-25%, while the turbulence intensity near the outlet of a conventional straight cavity is less than 2%.

[0078] (2) In vitro simulation experiment:

[0079] Platform: A transparent silicone tube (4mm inner diameter) was used to simulate a vein, providing a saline flow rate of 68 mL / min driven by a circulation pump. Methylene blue solution was used to simulate the drug.

[0080] Results Comparison: Commercial end-hole microcatheters compared with the drug delivery catheter of this application 1.

[0081] Results: The dye ejected from the drug delivery catheter 1 of this application formed a stained area in the simulated lesion region (partial silicone tube) that was 3.2 times larger than that of the control group, and the staining was more uniform. Through image analysis of dye concentration decay, it was found that after drug delivery via the catheter of this invention, the time required for the local dye concentration to drop to 50% of the initial value was 4.1 times that of the control group.

[0082] Tested on a three-dimensional mobile platform, the three-dimensional positioning error of the guidewire tip by the monitoring agency of this application was 2±1mm, and the attitude angle error was 5±3°, which meets the clinical millimeter-level navigation requirements.

[0083] Example 4: Based on the above examples, this application also proposes the following alternative implementation methods.

[0084] For higher blood flow (such as arterial applications), the drug delivery channel 102 can be a double helix but with a single diameter increased to 0.8 mm, or a variable helix angle design (5° at the inlet and 15° at the outlet) to balance anti-backflow and flow resistance.

[0085] For longer thrombi, a dumbbell-shaped cavity with a larger length-to-diameter ratio (e.g., a=2.1mm, b=1.4mm, L / D=1.5) can be used to form a double vortex structure at both ends, covering a longer range. The protrusions 105 on the inner wall can be replaced with an array of pits, a spiral guide groove, or a surface roughening treatment.

[0086] For drugs with higher viscosity (such as certain chemotherapy drugs), the infusion rate can be appropriately reduced (e.g., 2-3 mL / min), and the spiral tube angle can be re-optimized to ensure that the Dean number remains within the effective range.

[0087] For scenarios with limited budgets, a fixed array of three sensor rings (non-moving) can be used to replace the amount of data acquired by scanning by increasing the number of sensors (e.g., 3×6=18), but this will sacrifice some spatial resolution or increase the proximal outer diameter of the catheter.

[0088] In summary, the targeted drug delivery device with catheter posture monitoring proposed in this utility model addresses the problems of existing intravascular drug delivery catheters 1, such as easy dilution of drug solution by blood flow, short residence time in the target area, low drug utilization, uneven mixing of drug and lesion, insufficient penetration, lack of built-in real-time accurate positioning and posture sensing, cumbersome operation, and insufficient drug delivery accuracy. These problems are solved by anti-backflow channel design, structural optimization of turbulent mixing chamber 103, and integrated six-dimensional posture monitoring, ultimately achieving efficient, accurate, and safe intravascular targeted drug delivery.

[0089] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many improvements and modifications under the guidance of the present invention without departing from the spirit and scope of the claims. These improvements and modifications should also be considered within the scope of protection of the present invention.

[0090] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0091] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0092] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

Claims

1. A targeted drug delivery device with catheter position monitoring, characterized in that: The device includes a drug delivery catheter and a monitoring mechanism. The drug delivery catheter passes through the monitoring mechanism, which is used to monitor the position and orientation of the drug delivery catheter. The drug delivery catheter has a drug delivery channel, a mixing chamber, and a passage channel for a guidewire to pass through. The mixing chamber is located at the distal end of the drug delivery catheter and is sleeved on the outside of the passage channel. The drug delivery channel is spirally distributed around the axis of the passage channel and communicates with the mixing chamber. The outer side of the distal end of the drug delivery catheter has a drug outlet that communicates with the mixing chamber. The monitoring mechanism includes an excitation component, a sensor ring, and a drive component for driving the sensor ring to move linearly in the front-back direction. When the excitation component is energized, it generates an alternating magnetic field. The drug delivery catheter passes through the excitation component and the sensor ring in sequence, and the sensor ring is used to detect the magnetic induction intensity vector of the guidewire in the magnetic field.

2. The targeted drug delivery device with catheter position monitoring according to claim 1, characterized in that: The sensor ring includes an annular frame that can move in the front-back direction. A through hole is provided at the center of the annular frame for the passage of the drug delivery catheter. Multiple three-dimensional magnetic sensors are provided on the annular frame.

3. The targeted drug delivery device with catheter position monitoring according to claim 2, characterized in that: The monitoring mechanism also includes a support frame on which two drive components are disposed opposite each other. The annular frame is located between the two drive components, and the excitation component is connected to the support frame.

4. The targeted drug delivery device with catheter position monitoring according to claim 3, characterized in that: The drive assembly includes a support column and a drive motor arranged opposite each other in the front-rear direction. A drive wheel is installed at the output end of the drive motor, and a driven wheel is rotatably installed on the support column. A timing belt is fitted on the drive wheel and the driven wheel, and the inner edge of the timing belt is fixedly connected to the annular frame.

5. The targeted drug delivery device with catheter position monitoring according to claim 1, characterized in that: The mixing chamber is a rotating ellipsoidal structure, and multiple protrusions are provided on the inner wall of the mixing chamber. The protrusions are hemispherical and distributed at intervals along the axial direction of the drug delivery catheter.

6. The targeted drug delivery device with catheter position monitoring according to claim 5, characterized in that: The drug delivery channel is provided in three ways, and all three drug delivery channels are arranged in a spiral pattern around the axis of the passage channel.

7. The targeted drug delivery device with catheter position monitoring according to claim 2, characterized in that: The three-dimensional magnetic sensor is provided in six parts, and the six three-dimensional magnetic sensors are arranged in a circular array around the axis of the through hole.

8. The targeted drug delivery device with catheter position monitoring according to any one of claims 1-7, characterized in that: The proximal end of the drug delivery catheter is connected to a drive pump, the output end of the drive pump is connected to the drug delivery channel, and the distal end of the guidewire is connected to a permanent magnet.

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