Epidural catheter and epidural space catheterization position detection device

Abstract

The invention provides an epidural catheter which comprises a first catheter body or a second catheter body, one to five cavities are annularly formed in the end section of the insertion end of the first catheter body at equal intervals around the catheter, and sensors are arranged in the cavities; 1-5 sensors are annularly attached to the outer surface of the end section of the second guide pipe body at equal intervals around the guide pipe, and the outer surface of the second guide pipe body is further coated with a coating. The invention further provides an epidural space catheterization position detection device which comprises an epidural catheter, a connecting tube, a demodulator and an analgesia pump, the demodulator is suitable for converting and displaying signals received by the sensor or conducting early warning, and the demodulator is further suitable for controlling or adjusting drug administration parameters of the analgesia pump according to the received signals; according to the detection device, the position of the epidural catheter in the epidural cavity is judged through an electric signal, epidural administration can be more accurately carried out, and the problems of epidural catheter placement, position monitoring and the like in epidural cavity catheterization are solved.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an epidural catheter and an epidural cavity catheter placement position detection device. Background Art

[0002] Epidural catheterization has been widely used in surgical anesthesia, pain management, status bronchial asthma, ileus, and blood pressure reduction for severe eclampsia. The principle is to deliver medications through an epidural catheter through a continuous infusion or intermittent administration, allowing the drug to act on the spinal nerve roots. Traditional epidural catheterization relies on a "blind exploration" method based on feel and experience, which is subject to uncertainty and results in a failure rate of 13-23%. It can also lead to accidental injury to the spinal cord and nerves during the insertion and administration process. In practice, prolonged catheterization is often required. Patient movement, spinal flexion and extension, sweat, blood, surgical incision secretions, and changes in patient position can all lead to epidural catheter dislodgement, resulting in poor treatment efficacy and even causing the drug to enter the subarachnoid space, leading to serious adverse reactions.

[0003] Existing technologies primarily use epidural puncture needles equipped with pressure sensors or strain sensors. In these devices, the sensor is mounted on the tip of the needle or at the core of a syringe. The principle behind these devices is that resistance increases or decreases as the needle punctures various layers of tissue and ligaments. However, these devices often detect resistance changes after the puncture has already occurred, creating a "lag" problem. Cysts in the interspinous ligament, ligamentum flavum, paravertebral spaces, and muscle planes can also produce "false" resistance changes. Furthermore, these devices can only indicate the needle tip position during epidural puncture and are unable to provide detailed information on the epidural catheter's location during prolonged epidural catheterization. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an epidural catheter and an epidural catheter position detection device to solve the problem in the prior art that the specific position of the epidural catheter cannot be obtained when the epidural catheter is placed in the epidural cavity for a long time.

[0005] To achieve the above-mentioned and other related objectives, the present invention provides an epidural catheter, comprising a first catheter body or a second catheter body, wherein the tip section of the insertion end of the first catheter body is provided with 1 to 5 cavities at equal intervals around the catheter ring, wherein a sensor is provided in the cavity, wherein the cavity is provided with a concave film window, wherein the film window is provided on the outer surface of the first catheter body, wherein the sensor is connected to a first wire, and wherein the first wire is embedded in the first catheter body;

[0006] The outer surface of the end section of the second catheter body is equidistantly provided with 1 to 5 sensors around the catheter ring. The outer surface of the second catheter body is also covered with a coating. The sensors and the second wires connecting the sensors are arranged between the second catheter body and the coating.

[0007] The present invention also provides a method for preparing the epidural catheter as described above, wherein the method for preparing the epidural catheter including the first catheter body comprises the following steps:

[0008] 1) Extruding the material of the first catheter body, the material of the film window, and the sensor by micro-extrusion to obtain the first catheter body, and simultaneously embedding the sacrificial material into the first catheter body at a predetermined position of the wire;

[0009] 2) cooling and shaping the first catheter body obtained in step 1), then placing the first catheter body in a dissolving solution to dissolve and remove the sacrificial material, thereby obtaining a guidewire channel on the first catheter body, implanting the first guidewire into the guidewire channel using vacuum traction, and perfusing the guidewire channel with the material of the first catheter body or a biocompatible epoxy resin, and curing the solution to obtain the epidural catheter;

[0010] The method for preparing the epidural catheter including the second catheter body (20) comprises the following steps:

[0011] a) Paste the sensor and the second wire onto the outer surface of the second catheter body to obtain a second catheter body containing the sensor:

[0012] b) obtaining a coating material solution, uniformly coating the solution on the outer surface of the second catheter body containing the sensor, and curing the solution at room temperature to obtain the epidural catheter.

[0013] The present invention also provides an epidural catheter placement position detection device, which includes: the epidural catheter and connecting tube, a demodulator and an analgesia pump as described above, one end of the connecting tube is connected to the analgesia pump, and the other end is connected to the epidural catheter, the sensor on the epidural catheter is connected to the demodulator through a first wire or a second wire, the demodulator is suitable for converting and displaying the signal received by the sensor or issuing an early warning, and the analgesia pump is also connected to the demodulator.

[0014] As described above, the epidural catheter and the epidural catheter position detection device of the present invention have the following beneficial effects:

[0015] The epidural catheter of the present invention is equipped with a sensor in the cavity at the end of the catheter body to determine the position of the epidural catheter in the epidural cavity through electrical signals during use. Multiple sensors are arranged in a ring to achieve multi-angle scanning. The thin film window provided on the cavity not only protects the sensor, but also its concave design can concentrate the sound beam and improve lateral resolution.

[0016] The epidural catheter position detection device of the present invention connects a sensor in the epidural catheter to a demodulator via a wire, enabling real-time monitoring of the epidural catheter's position. The analgesic pump then precisely delivers medication via the connecting tube and the epidural catheter. The device is portable and allows for real-time monitoring of the epidural catheter's position and medication delivery. This device addresses the challenges of epidural catheter placement and position monitoring during epidural catheterization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the positions of the first catheter body, the film window, and the guide wire of the present invention.

[0018] Figure 2 This is a schematic cross-sectional view of the epidural catheter tip cavity of Example 1.

[0019] Figure 3 This is a schematic cross-sectional view of the epidural catheter tip cavity of Example 2.

[0020] Figure 4 Schematic diagram of the structure of the epidural space catheter position detection device of the present invention.

[0021] Figure 5 Schematic diagram of the linear connection of the epidural space catheter position detection device of the present invention.

[0022] Figure 6 Schematic diagram of the mold.

[0023] In the figure, 10, first catheter body; 20, second catheter body; 2, first wire; 3, film window; 4, wire redundancy ring; 5, coating; 7, sensor; 30, demodulator; 40, analgesia pump; 50, connecting tube; 60, cavity; 70, hollow column. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] In the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise expressly specified or limited. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0026] When a numerical range is disclosed herein, the above range is deemed to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein. For example, a specified range from "1 to 10" should be deemed to include any and all subranges between a minimum of 1 and a maximum of 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, and the like.

[0027] Please refer to the accompanying drawings. It should be noted that the illustrations provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the drawings only show components relevant to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be varied arbitrarily, and the component layout may also be more complex.

[0028] Furthermore, it should be understood that the one or more method steps mentioned in the present invention do not exclude the presence of other method steps before or after the combination step, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. It should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the presence of other devices / apparatuses before or after the combination device / apparatus, or the insertion of other devices / apparatuses between two explicitly mentioned devices / apparatuses, unless otherwise specified. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the present invention.

[0029] A first aspect of the present invention provides an epidural catheter, comprising a first catheter body 10 or a second catheter body 20, wherein the tip section of the insertion end of the first catheter body 10 is provided with 1 to 5 cavities at equal intervals around the catheter ring, wherein a sensor is provided in the cavity, wherein the cavity is provided with a concave film window 3, wherein the film window 3 is provided on the outer surface of the first catheter body 10, wherein the sensor is connected to a first wire 2, wherein the first wire 2 is embedded in the first catheter body 10;

[0030] The outer surface of the end section of the second catheter body 20 is provided with 1 to 5 sensors at equal intervals around the catheter ring. The outer surface of the second catheter body 20 is also covered with a coating 5. The sensors and the second wires connecting the sensors are both provided between the second catheter body 20 and the coating 5.

[0031] The term "around the catheter at equal intervals" in the present invention refers to being arranged in a circular ring on the circular cross section of the catheter. Figure 2 shown.

[0032] The epidural catheter of the present invention is configured such that a sensor is installed in the end cavity of the insertion end of the catheter body; or the sensor is attached to the outside of the catheter body head end, and a coating is provided to ensure that the sensor and the wire do not fall off. The epidural catheter of the present invention not only does not block the delivery of the anesthetic solution, but also can more accurately detect the location of drug action.

[0033] In the epidural catheter of the present invention, the first catheter body 10 and the second catheter body 20 are both made of flexible biocompatible materials. In a preferred embodiment of the present invention, the first catheter body 10 and the second catheter body 20 are made of medical polyurethane (PU) or silicone.

[0034] In the epidural catheter of the present invention, the material of the film window 3 is a thermoplastic polyurethane elastomer (TPU) film.

[0035] If the catheter body is made of polyurethane (PU), controlling the material viscosity ratio (η(TPU) / η(PU)) to 0.8 to 1.2 can prevent delamination, stress concentration, and uneven flow at the interface caused by large viscosity differences. A transition zone width of less than 20 μm indicates sufficient diffusion and molecular bonding between the two phases at the microscopic level.

[0036] In the epidural catheter of the present invention, the sensor is selected from a pressure sensor, an ultrasonic sensor, an optical sensor, an electromagnetic tracking sensor, an electromagnetic ultrasonic sensor, and a near-infrared tracking system.

[0037] In the epidural catheter of the present invention, the thickness of the film window 3 is ≤10 μm.

[0038] In the epidural catheter of the present invention, the diameter of the film window 3 is 0.5 to 1 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm.

[0039] In the epidural catheter of the present invention, the curvature radius of the concave surface of the film window 3 is 2 to 5 mm, for example, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm.

[0040] In the epidural catheter of the present invention, the acoustic impedance of the thin film window 3 is 1.5 to 2.0 Mrayl, for example, 1.5 Mrayl, 1.6 Mrayl, 1.7 Mrayl, 1.8 Mrayl, 1.9 Mrayl or 2.0 Mrayl.

[0041] In the epidural catheter of the present invention, the distance between the sensor and the catheter tip is 0-0.5 cm, for example, 0-0.1 cm, 0.1-0.2 cm, 0.2-0.3 cm, 0.3-0.4 cm, or 0.4-0.5 cm.

[0042] The epidural catheter of the present invention has an insertion end provided with scales with a spacing of 1 cm from the end.

[0043] The epidural catheter of the present invention further comprises a side hole formed in the catheter wall of the tip section of the epidural catheter. The diameter of the side hole is 0.5 to 1.0 mm, for example, 0.5 to 0.6 mm, 0.6 to 0.7 mm, 0.7 to 0.8 mm, 0.8 to 0.9 mm, or 0.9 to 1.0 mm. This is suitable for increasing the spray range of the drug solution and reducing the injection pressure of the drug solution.

[0044] In the epidural catheter of the present invention, the coating has a thickness of 0.5 to 0.6 mm, for example, 0.5 to 0.52 mm, 0.52 to 0.54 mm, 0.54 to 0.56 mm, 0.56 to 0.58 mm, or 0.58 to 0.6 mm.

[0045] In the epidural catheter of the present invention, the wire 2 is spirally wound around the catheter body with a pitch of 0.5 to 2 mm starting from the sensor, and then arranged linearly along the length of the catheter body. The spiral wiring increases the bending life by 8 times compared to the linear wiring.

[0046] In a preferred embodiment of the present invention, the conductor is provided with a redundant conductor loop 4 having a diameter of 0.2-0.5mm, 0.2-0.3mm, 0.3-0.4mm or 0.4-0.5mm at a distance of 1-3mm, 1-2mm or 2-3mm from the sensor. The redundant conductor loop 4 can absorb bending deformation.

[0047] A second aspect of the present invention provides a method for preparing the epidural catheter as described above, wherein the method for preparing the epidural catheter including the first catheter body 10 comprises the following steps:

[0048] 1) Extruding the material of the first catheter body, the material of the film window, and the sensor by micro-extrusion to obtain the first catheter body 10, and simultaneously embedding the sacrificial material into the first catheter body 10 at a predetermined position of the wire;

[0049] 2) Cooling and shaping the first catheter body 10 obtained in step 1), and then placing it in a dissolving solution to dissolve and remove the sacrificial material, thereby obtaining a guidewire channel on the first catheter body. Implanting the first guidewire 2 into the guidewire channel by vacuum traction, and perfusing the guidewire channel with the material of the first catheter body or a biocompatible epoxy resin, which is then cured to obtain the epidural catheter.

[0050] The method for preparing the epidural catheter including the second catheter body 20 comprises the following steps:

[0051] a) adhering the sensor and the second wire to the outer surface of the second catheter body 20 to obtain the second catheter body 20 containing the sensor;

[0052] b) obtaining a material solution of the coating 5, uniformly coating the solution on the outer surface of the second catheter body (20) containing the sensor, and curing it at room temperature to obtain the epidural catheter.

[0053] Wherein, in the preparation method of the present invention, in steps 1) and 2), the sacrificial material is polyvinyl alcohol (PVA). Preferably, the sacrificial material is selected from PVA 1799 or PVA 2488.

[0054] In the preparation method of the present invention, in step 1), the material of the catheter body is extruded at a temperature of 180° C. The material of the film window is extruded at a low temperature of 160° C. to prevent degradation.

[0055] In the preparation method of the present invention, in step 2), the dissolving liquid is a 10-30% v / v ethanol / water solution. For example, it is a 10-15% v / v, 15-20% v / v, 20-25% v / v, or 25-30% v / v ethanol / water solution. In the preparation method of the present invention, the cooling and setting in step 2) is performed by cooling in water at 20°C.

[0056] In the preparation method of the present invention, the vacuum traction in step 2) is to apply a negative pressure of -80 kPa at one end of the guidewire channel. The guidewire is implanted at a speed of 0.3 m / min, and the tension is controlled to be less than 0.05 N.

[0057] In the preparation method of the present invention, the curing in step 2) is performed by irradiating the sample with 365 nm ultraviolet light for 60 seconds (intensity 50 mW / cm2 ).

[0058] In the preparation method of the present invention, the second catheter body 20 containing the sensor in step a) can also be prepared by the following method:

[0059] (1) The second catheter body 20 is prepared by extrusion: before the second catheter body 20 is prepared, the sensor and the wire are placed in an extrusion die, and extrusion is started to ensure that the sensor and the wire are wrapped in the prepared second catheter body 20;

[0060] (2) The second catheter body 20 is rapidly cooled after extrusion to solidify and maintain its shape; ensuring that the sensor and its wires do not move during the cooling process, thereby obtaining the second catheter body 20 containing the sensor;

[0061] (3) The second catheter body 20 containing the sensor is surface treated to remove excess material and burrs.

[0062] In the preparation method of the present invention, the pasting described in step a) adopts the method of biocompatible glue bonding + laser welding or curing. The specific process steps include: 1. Positioning point pretreatment: plasma cleaning the surface of the second catheter body 20, and pre-coating biocompatible glue at the position of the corresponding sensor; 2. Sensor fitting: using a micro-positioning fixture to accurately fit the sensor, laser welding or UV curing or thermal curing; 3. Protective layer coating: covering the second catheter body 20 with a protective layer of the same material, smoothing the edge to avoid scratching the tissue. The biocompatible glue is selected from one or more of collagen glue, gelatin, silk fibroin glue, sodium alginate glue, chitosan glue, hyaluronic acid glue, polymer-based glue, polyurethane glue, silicone rubber glue, polylactic acid (PLA) cyanoacrylate glue, epoxy resin glue, porous hydrogel, self-healing hydrogel, conductive hydrogel, nano-enhanced glue, and light-curing glue.

[0063] In the preparation method of the present invention, the solution in step b) is evenly coated on the outer surface of the catheter body 1 containing the sensor. A mold method can be used, such as placing the second catheter body containing the sensor into the mold, introducing the solution of the coating material into the mold, and removing the mold after curing at room temperature to obtain the epidural catheter coated with the coating. The mold can be obtained by 3D printing. The structure of the mold is as follows Figure 6 The middle column 70 is suitable for fixing the catheter body containing the sensor, and the cavity 60 is suitable for adding a solution of the coating material.

[0064] In the preparation method of the present invention, the raw material of the coating 5 in step b) is commercially available dragon skin 20, which contains component A and component B; the solution of the coating 5 is obtained by uniformly mixing component A and component B in equal proportions.

[0065] The third aspect of the present invention provides an epidural catheter placement position detection device, which includes: the epidural catheter and connecting tube 50, a demodulator 30 and an analgesia pump 40 as described above, one end of the connecting tube 50 is connected to the analgesia pump 40, and the other end is connected to the epidural catheter, the sensor on the epidural catheter is connected to the demodulator 30 through the first wire 2 or the second wire, the demodulator 30 is suitable for converting the signal received by the sensor and displaying or issuing an early warning, and the analgesia pump 40 is also connected to the demodulator 30.

[0066] In the detection device of the present invention, the connecting tube 50 is connected to the epidural catheter 10 via an infusion connector.

[0067] In the detection device of the present invention, the demodulator 30 includes a power module, an output module, a control switch, and two display screens. The sensor on the epidural catheter is connected to the output module via a first wire 2 or a second wire 4. The control switch electrically connects the display screen to the output module, and the output module is electrically connected to the display screen. The sensor, output module, and display screen are each electrically connected to the power module. One display screen is suitable for displaying sensor signal data or warning signals, and the other display screen is suitable for displaying parameters of the analgesia pump, such as background dose, PCA dose, lockout time, etc.

[0068] The output module includes a comparator and a processor. When in use, the sensor collects signals and transmits the collected signals to the connected comparator. The comparator compares and processes the received signals with the data stored in the processor, and then displays the detected data on the display.

[0069] The demodulator 30 further includes a Bluetooth module, which is electrically connected to the power module and the output module.

[0070] In the detection device of the present invention, the sensor is selected from one of a pressure sensor, an ultrasonic sensor, an optical sensor, an electromagnetic tracking sensor, an electromagnetic ultrasonic sensor, and a near-infrared tracking system.

[0071] The optical sensor is selected from one of a light intensity sensor, a photodiode, a phototransistor, a phototube, a photoelectric encoder, an incremental encoder, an absolute encoder, a fiber optic sensor, an internal sensor, an external sensor, an image sensor, a CMOS sensor, a CCD sensor, a color sensor, a position sensor, a grating ruler, a laser distance meter, a spectrum sensor, a spectrophotometer, a fluorescence sensor, an interferometer, a wavelength sensor, a laser sensor and an optical fiber temperature sensor.

[0072] The near-infrared tracking system is selected from one of an active tracking system, a passive tracking system, a time-series brightness tracking system, a stereoscopic vision tracking system, a structured light tracking system, a time-of-flight tracking system, a phase difference tracking system, and a hybrid tracking system.

[0073] The ultrasonic sensor is a piezoelectric ultrasonic sensor.

[0074] The piezoelectric material used in piezoelectric ultrasonic sensors is a type of material with unique physical properties that enables the conversion of electrical signals into mechanical motion. The piezoelectric effect of this material stems from the asymmetry of its lattice structure. When an external force acts on the piezoelectric material, it causes an uneven distribution of charge within it, generating a potential difference and, consequently, a charge signal. Conversely, when an electric field is applied, the charge distribution within the material also changes, causing mechanical motion. This is known as the inverse piezoelectric effect.

[0075] Piezoelectric ultrasonic sensors operate based on the piezoelectric effect of piezoelectric materials. They consist of two components: a generator and a receiver. The generator converts high-frequency electrical vibrations into high-frequency mechanical vibrations, thereby generating ultrasonic waves. Different tissues in the human body have varying propagation speeds and absorption rates for ultrasonic waves. When the reflected echo hits the receiver, causing the crystal to expand and contract, generating charges of opposite polarity on its two surfaces. These charges are converted into voltage, amplified, and sent to a measurement circuit for recording or display. The resulting electrical signal can be used to identify the tissue surrounding the epidural catheter tip, inferring its exact location and providing objective data support for subsequent medication and treatment.

[0076] Example 1

[0077] Preparation of epidural catheter:

[0078] 1) The material of the first catheter body (medical polyurethane), the material of the film window 3 (TPU), and three ultrasonic sensors are extruded by micro-extrusion, and PVA1799 is synchronously embedded into the extruded first catheter body at a predetermined wire position; the diameter of the film window 3 is 0.8 mm, the radius of curvature of the concave surface of the film window 3 is 3 mm, and the acoustic impedance of the film window 3 is 1.8 Mrayl; the distance between the sensor and the end of the insertion end of the epidural catheter is 0.2 cm, and the insertion end of the epidural catheter is provided with a scale with a spacing of 1 cm from the end; the catheter wall of the end section of the epidural catheter is also provided with a side hole, and the diameter of the side hole is 0.5 mm; the first wire 2 is spirally wound around the catheter body with a pitch of 1 mm from the sensor, and then is linearly arranged on the catheter along the length direction of the catheter body; a wire redundant loop with a diameter of 0.3 mm is provided 2 mm from the sensor;

[0079] 2) The first catheter body 10 obtained in step 1) was cooled and shaped, and then placed in a dissolving solution (10% v / v ethanol / water solution, which was gradually heated to 60° C.) for 2 h to dissolve and remove the PVA. A guidewire channel was obtained on the first catheter body. A guidewire was implanted into the first guidewire channel 2 using a vacuum traction method (applying a negative pressure of -80 kPa at one end of the guidewire channel) (the guidewire was implanted at a speed of 0.3 m / min and the tension was controlled to be <0.05 N). A biocompatible epoxy resin was poured into the guidewire channel and cured (irradiated with 365 nm ultraviolet light for 60 seconds at an intensity of 50 mW / cm 2 ), obtain the epidural catheter, such as Figures 1-2 shown.

[0080] Example 2

[0081] Preparation of epidural catheter:

[0082] like Figure 2 As shown, an ultrasonic sensor and a second wire are attached to the outer surface of the second catheter body 20 using epoxy resin glue. The insertion end of the epidural catheter is provided with a scale with a spacing of 1 cm from the end; a side hole is also provided on the catheter wall of the end section of the epidural catheter, and the diameter of the side hole is 0.8 mm; the second wire is spirally wound on the catheter body with a pitch of 2 mm from the sensor, and then is straightly arranged on the catheter along the length direction of the catheter body; a redundant wire loop with a diameter of 0.5 mm is provided 3 mm away from the sensor. The second catheter body 20 with the sensor attached is fixed to the mold ( Figure 6 )middle;

[0083] The coating material is dragon skin 20. Component A and component B are mixed to obtain a mixed solution. The mixed solution is added to a mold and cured at room temperature for 1 hour. The mold is removed. The coating thickness is 0.5 mm, and an epidural catheter is obtained. Figure 3 shown.

[0084] Example 3

[0085] An epidural catheter position detection device includes the epidural catheter and connecting tube 50, demodulator 30 and analgesia pump 40 described in Example 1, one end of the connecting tube 50 is connected to the analgesia pump 40, and the other end is connected to the epidural catheter through an infusion connector, the sensor on the epidural catheter is connected to the demodulator 30 through a first wire 2, the demodulator 30 includes a power module, an output module, a Bluetooth module, a control switch and two display screens, the control switch electrically connects the display screen and the output module, the sensor on the epidural catheter is connected to the output module through a first wire 2, the output module is electrically connected to the display screen and the Bluetooth module, the sensor, output module, Bluetooth module and display screen are electrically connected to the power module respectively, wherein one display screen displays the signal or warning signal of the sensor, and the other display screen displays the parameters of the analgesia pump; the demodulator 30 is suitable for converting and displaying the signal received by the sensor or issuing an early warning, and the analgesia pump 40 is also connected to the demodulator 30, such as Figures 3-4 shown.

[0086] When using the epidural space catheter position detection device of the present invention, it is necessary to accurately locate the puncture point before performing epidural puncture. According to the patient's expected range of drug action, select a suitable intervertebral space for puncture. Determine the specific location of the intervertebral space through palpation or imaging guidance. The patient can take a side-lying or sitting position with the back slightly tilted forward to increase the intervertebral space and improve the success rate of puncture. Strictly disinfect the selected puncture area and lay a sterile single towel. Specific steps:

[0087] 1. Perform local infiltration anesthesia on the skin and subcutaneous tissue at the puncture point to reduce the pain during puncture.

[0088] 2. Use the frontal approach or lateral approach to position, place the epidural puncture needle perpendicular to the skin, and advance slowly.

[0089] 3. First penetrate the subcutaneous tissue and ligament layer. You will feel a certain resistance when passing through the ligament layer.

[0090] 4. When the needle tip passes through the yellow ligament and enters the epidural space, the resistance suddenly decreases, and there will be a "beating" or "hollow" feeling in the hand.

[0091] 5. Remove the inner core of the puncture needle and observe whether there is reflux of cerebrospinal fluid or blood through the syringe connected to the puncture needle. If there is no abnormal reflux, it indicates that the puncture needle is correctly located in the epidural space.

[0092] 6. Slowly insert the epidural catheter 10 into the epidural space using the puncture needle. The epidural catheter placement depth is 4-5 cm, which can be initially determined by the scale on the epidural catheter 10. After confirming the correct position of the epidural catheter 10 tip based on the detection parameters displayed on the demodulator 30 screen, remove the epidural puncture needle and secure the epidural catheter 10 to the patient's skin using medical tape or skin sutures. Mark the exit of the epidural catheter 10. At this point, determine the position data of the epidural catheter 10 tip on the demodulator 30, record the initial position coordinates (x, y, z error ≤ ±1 mm), set a threshold (1 mm), and establish a three-dimensional catheter model.

[0093] 7. After the epidural puncture and catheter placement are complete, the position of the epidural catheter 10 is closely monitored using the detection device of the present invention, transmitting position data every 5 seconds. This data is also transmitted to the medical terminal via the Bluetooth module. Changes in the patient's vital signs, sensory, and motor functions are simultaneously observed. The demodulator 30 controls the analgesic pump 40 to deliver medication regularly through the connecting tube 20 and the catheter body 1. The sensor 3 also provides real-time feedback on the position of the epidural catheter through the demodulator 30. Medical staff also regularly inspect the puncture site for signs of infection, such as redness, swelling, and exudation, to ensure patient safety and comfort. If the total displacement detected is greater than 1 mm, a red warning appears on the display screen, and an alarm message is simultaneously sent to the medical terminal via the Bluetooth module to remind medical staff to check or adjust the position.

[0094] In summary, the epidural catheter position detection device of the present invention installs a sensor on the outside of the head end of the epidural catheter, and the sensor is connected to a demodulator, thereby converting the detected signal into a digital signal or a three-dimensional image signal, which is convenient for real-time observation and detection of the position of the epidural catheter; at the same time, an analgesic pump is also provided to be connected to the demodulator, which can monitor the parameters of the analgesic pump in real time. Compared with the traditional empirical judgment method, the epidural catheter position detection device of the present invention can more accurately administer epidural medication and monitor the position of the epidural catheter, solving the problems of epidural catheter placement and position monitoring in epidural catheterization.

[0095] Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0096] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An epidural catheter, characterized in that: It comprises a first catheter body (10) or a second catheter body (20); The tip section of the insertion end of the first catheter body (10) is provided with 1 to 5 cavities at equal intervals around the catheter ring, wherein a sensor is provided in the cavity, and the cavity is provided with a concave film window (3), wherein the film window (3) is provided on the outer surface of the first catheter body (10), and the sensor is connected to a first wire (2), and the first wire (2) is embedded in the first catheter body (10); The outer surface of the end section of the second catheter body (20) is provided with 1 to 5 sensors at equal intervals around the catheter ring. The outer surface of the second catheter body (20) is also covered with a coating (5). The sensors and the second wires connecting the sensors are both provided between the second catheter body (20) and the coating (5).

2. The epidural catheter according to claim 1, wherein The materials of the first catheter body (10) and the second catheter body (20) are both flexible biocompatible materials, preferably selected from medical polyurethane or silicone; And / or, the material of the film window (3) is a thermoplastic polyurethane elastomer film; And / or, the sensor is selected from one of a pressure sensor, an ultrasonic sensor, an optical sensor, an electromagnetic tracking sensor, an electromagnetic ultrasonic sensor, and a near-infrared tracking system.

3. The epidural catheter according to claim 1, wherein The thickness of the film window (3) is ≤10 μm; and / or, the diameter of the film window (3) is 0.5 to 1 mm; and / or, the curvature radius of the concave surface of the film window (3) is 2 to 5 mm; and / or, the acoustic impedance of the film window (3) is 1.5 to 2.0 Mrayl; and / or, the sensor is at a distance of 0 to 0.5 cm from the tip of the insertion end of the epidural catheter; and / or, the insertion end of the epidural catheter is provided with scales spaced 1 cm apart from the tip; And / or, a side hole is further provided on the catheter wall of the end section of the epidural catheter, and the diameter of the side hole is 0.5-1.0 mm.

4. The epidural catheter according to claim 1, wherein The coating (5) has a thickness of 0.5 to 0.6 mm; and / or the first wire (2) or the second wire is spirally wound on the catheter body starting from the sensor with a pitch of 0.5 to 2 mm, and then arranged on the catheter in a straight line along the length direction of the catheter body.

5. A method for preparing an epidural catheter according to any one of claims 1 to 5, characterized in that: The method for preparing the epidural catheter including the first catheter body (10) comprises the following steps: 1) Extruding the material of the first catheter body, the material of the film window, and the sensor by micro-extrusion to obtain the first catheter body (10), and simultaneously embedding the sacrificial material into the first catheter body (10) at a predetermined position of the wire; 2) cooling and shaping the first catheter body obtained in step 1), and then placing it in a dissolving solution to dissolve and remove the sacrificial material, thereby obtaining a wire channel on the first catheter body, implanting the first wire (2) into the wire channel by vacuum traction, and pouring the material of the first catheter body or a biocompatible epoxy resin into the wire channel, and curing to obtain the epidural catheter; The method for preparing the epidural catheter including the second catheter body (20) comprises the following steps: a) adhering the sensor and the second lead to the outer surface of the second catheter body (20) to obtain the second catheter body (20) containing the sensor; b) obtaining a material solution of the coating (5), uniformly coating the solution on the outer surface of the second catheter body (20) containing the sensor, and curing it at room temperature to obtain the epidural catheter.

6. The method for preparing an epidural catheter according to claim 6, characterized in that: In steps 1) and 2), the sacrificial material is polyvinyl alcohol; And / or, in step 2), the dissolving liquid is a 10-30% v / v ethanol / water solution.

7. An epidural space catheter position detection device, characterized in that: The detection device includes: an epidural catheter and a connecting tube (50), a demodulator (30) and an analgesia pump (40) as described in any one of claims 1 to 4, one end of the connecting tube (50) is connected to the analgesia pump (40), and the other end is connected to the epidural catheter, the sensor on the epidural catheter is connected to the demodulator (30) through a first wire (2) or a second wire, the demodulator (30) is suitable for converting the signal received by the sensor and displaying or issuing an early warning, and the analgesia pump (40) is also connected to the demodulator (30).

8. The epidural space catheter position detection device according to claim 5, characterized in that: The connecting tube (50) is connected to the epidural catheter (10) via an infusion connector; And / or, the demodulator (30) includes a power module, an output module, a control switch and two display screens, the sensor on the epidural catheter is connected to the output module via a first wire (2) or a second wire, the control switch electrically connects the display screen and the output module, the output module is electrically connected to the display screen, the sensor, output module and display screen are electrically connected to the power module respectively, wherein one display screen is suitable for displaying the signal data or warning signal of the sensor, and the other display screen is suitable for displaying the parameters of the analgesia pump.

9. The epidural space catheter position detection device according to claim 5, characterized in that: The sensor is selected from one of a pressure sensor, an ultrasonic sensor, an optical sensor, an electromagnetic tracking sensor, an electromagnetic ultrasonic sensor, and a near-infrared tracking system.

10. The epidural space catheter position detection device according to claim 9, characterized in that: The optical sensor is selected from one of a light intensity sensor, a photodiode, a phototransistor, a phototube, a photoelectric encoder, an incremental encoder, an absolute encoder, a fiber optic sensor, an internal sensor, an external sensor, an image sensor, a CMOS sensor, a CCD sensor, a color sensor, a position sensor, a grating ruler, a laser distance meter, a spectrum sensor, a spectrophotometer, a fluorescence sensor, an interferometer, a wavelength sensor, a laser sensor, and an optical fiber temperature sensor; and / or, the near-infrared tracking system is selected from one of an active tracking system, a passive tracking system, a time-series brightness tracking system, a stereoscopic vision tracking system, a structured light tracking system, a time-of-flight tracking system, a phase difference tracking system, and a hybrid tracking system; And / or, the ultrasonic sensor is a piezoelectric ultrasonic sensor.

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