Intracranial pressure sensor probe capable of resisting intracranial tissue interference

Abstract

The utility model discloses an intracranial pressure sensor probe capable of resisting intracranial tissue interference, which comprises a sensor catheter and a closed catheter head which are matched to form a probe end, a pressure sensor and a sensor wire which are connected are arranged in the sensor catheter, and the pressure sensor is arranged at the end and close to the closed catheter head. A plurality of through holes used for drainage are formed in the tube wall of the sensor catheter close to the pressure sensor. The utility model further discloses a structure of the pressure sensor, the structure comprises the sensor substrate and the sensor film covering the sensor substrate, the edge of the sensor substrate is provided with a flexible bending structure, and the flexible bending structure and the inner wall of the sensor conduit are fixed through ultrasonic welding. The surface of the sensor film is prevented from being covered by soft tissue, so that intracranial pressure monitoring data are stable; and the production difficulty and cost are reduced by adopting an ultrasonic welding mode.

Description

Technical Field

[0001] The present application relates to an intracranial pressure sensor, belonging to the field of pressure sensors, and particularly to an intracranial pressure sensor probe resistant to intracranial tissue interference. Background Art

[0002] In the publicly disclosed intracranial pressure monitoring technologies, piezoresistive sensors can measure static values and better meet the current clinical application requirements compared with piezocapacitive sensors. However, for the current intracranial pressure probes based on piezoresistive sensors, since the sensors are exposed outside the probes and directly contact with intracranial tissues, during use, they are prone to being covered and infected by intracranial tissues, resulting in sensitivity drift and zero drift of the sensors, and it is difficult to accurately present data through hardware compensation and software compensation.

[0003] In the existing process manufacturing technology, first, the sensor is encapsulated in a metal shell, the lead wires are led out, and then it is put into a catheter for secondary encapsulation. The process steps are cumbersome, the assembly process is complex, and the production cost is high.

[0004] Integrating the sensor inside the intracranial pressure probe is a feasible solution. The patent with the publication number CN 113413500 A provides a solution for an integrated system of intracranial drainage and intracranial pressure measurement, adopting a structure in which a thin-film pressure sensor is provided on the inner wall of one end of a drainage tube inserted into the patient's ventricle. However, in practice, the processing method of this structure still has problems such as being relatively complex, having high production accuracy requirements, and low production efficiency, resulting in a relatively high production cost. Utility Model Content

[0005] According to one aspect of the present application, an intracranial pressure sensor probe resistant to intracranial tissue interference is provided, which can ensure good stability of pressure test data and reduce production costs at the same time.

[0006] The intracranial pressure sensor probe resistant to intracranial tissue interference includes a sensor catheter and a closed catheter head, which are fixedly connected to form the end of the sensor probe;

[0007] Inside the sensor catheter, there are a pressure sensor and sensor wires; the pressure sensor is arranged near the closed catheter head and fixedly connected to the inner wall of the catheter; the sensor wires are connected to the pressure sensor;

[0008] On the wall of the sensor catheter near the pressure sensor, there are also through holes for drainage provided.

[0009] Optionally, the pressure sensor includes: a sensor substrate and a sensor film having the same size as the sensor substrate;

[0010] The sensor substrate is arranged along the axial direction of the inner cavity of the sensor catheter, and its radial edge is fixedly connected to the inner wall of the catheter;

[0011] The sensor film covers the thin-film sensing material on the sensor substrate.

[0012] Optionally, the pressure sensor is disposed at a position 1-5 mm away from the closed catheter head.

[0013] Optionally, the edge of the sensor substrate has a flexible bending structure for complete contact with the inner wall of the sensor catheter.

[0014] Optionally, the length of the sensor substrate is 1-5 mm.

[0015] Optionally, the width of the sensor substrate is 0.7-3 mm.

[0016] Optionally, the thickness of the sensor substrate is 0.1-0.5 mm.

[0017] Optionally, the distance from one end of the sensor substrate close to the probe tip is 0.1-3 mm.

[0018] Optionally, the thin-film sensing material includes an upper carbonized nanofiber membrane, a pressure-sensitive film, and a lower carbonized nanofiber membrane stacked in sequence; the upper carbonized nanofiber membrane and the lower carbonized nanofiber membrane are connected to an intracranial pressure monitor through the sensor wire.

[0019] Optionally, the upper carbonized nanofiber membrane, the pressure-sensitive film, and the lower carbonized nanofiber membrane have the same thickness.

[0020] Optionally, the thin-film sensing material is disposed on one or both sensing surfaces of the sensor substrate.

[0021] Optionally, the inner wall material of the sensor catheter is selected from one or a mixture of TPU, PA, and TPEE.

[0022] Optionally, the material of the sensor substrate is selected from one or a mixture of PET and stainless steel.

[0023] Optionally, the outside of the sensor wire is provided with a polymer resin protective layer, and the position where the outside of the polymer resin protective layer contacts the inner wall of the catheter is fixed by ultrasonic welding.

[0024] Optionally, the sensor wire segment includes 2-4 electrode wires, that is, at least including positive and negative wiring, and ground wires and functional wires can be selectively added.

[0025] Optionally, the opening angle of the through hole along the circumferential direction of the sensor catheter is: 15°-60°.

[0026] Optionally, the diameter of the sensor catheter is 1 to 3 mm; the size of the through hole in the radial direction of the sensor catheter is 0.5 to 3 mm; the number of through holes is 9 to 36, and the arrangement is (3 to 6) * (3 to 6).

[0027] Optionally, the closed catheter head is hemispherical.

[0028] The beneficial effects that this application can produce include:

[0029] 1) The intracranial pressure sensor probe provided by this application, which resists interference from intracranial tissues, can avoid soft tissues covering the surface of the sensor membrane. Compared with the direct exposure method of the unilateral window sensor, the intracranial pressure monitoring data is stable, and the production difficulty and cost are greatly reduced by using the ultrasonic welding method.

[0030] 2) The combination selection of the inner wall material of the sensor catheter and the sensor substrate material provided by this application can facilitate the ultrasonic welding of the two. Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of the intracranial pressure sensor probe that resists interference from intracranial tissues in an embodiment of this application;

[0032] Figure 2 is a schematic structural diagram of the pressure sensor in an embodiment of this application;

[0033] Figure 3 is a schematic diagram of the processing method of the intracranial pressure sensor probe that resists interference from intracranial tissues in an embodiment of this application;

[0034] Figure 4 is a schematic connection diagram of the intracranial pressure sensor probe and the intracranial pressure monitor in an embodiment of this application;

[0035] Figure 5 is a schematic diagram of the working principle of the pressure sensor in an embodiment of this application. Detailed Embodiments

[0036] The following describes this application in detail with reference to the embodiments, but this application is not limited to these embodiments.

[0037] As Figure 1 shown, this application provides an intracranial pressure sensor probe that resists interference from intracranial tissues, including a sensor catheter and a closed catheter head, which are fixedly connected to form the end of the sensor probe;

[0038] A pressure sensor and a sensor wire are arranged inside the sensor catheter; the pressure sensor is arranged near the closed catheter head and is fixedly connected to the inner wall of the catheter; the sensor wire is connected to the pressure sensor;

[0039] There are also through holes for drainage provided on the tube wall of the sensor catheter near the pressure sensor.

[0040] In one embodiment, the pressure sensor includes: a sensor substrate and a sensor film having the same size as the sensor substrate;

[0041] The sensor substrate is arranged axially along the inner cavity of the sensor catheter, and its radial edge is fixedly connected to the inner wall of the catheter;

[0042] The sensor film is a thin film sensing material covering the sensor substrate.

[0043] In one embodiment, the pressure sensor is arranged at a position 1 - 5 mm away from the closed catheter head.

[0044] In one embodiment, as Figure 2 shown, in the inner cavity of the sensor catheter, at a position 3 mm close to the catheter end, a PET - material sensor substrate with thin film sensing material covering both sides is arranged horizontally. The two end edges of the sensor substrate along the radial direction of the catheter are fixed to the inner wall of the catheter by ultrasonic welding. There are 18 through holes for drainage on the probe catheter wall. The through holes are arranged equidistantly at a 2 - mm interval along the radial direction of the catheter. The opening angle of the through holes along the circumferential direction of the catheter is 60°, and the size of the through holes along the radial direction of the catheter is 12 mm.

[0045] In one embodiment, the thin film sensing material includes an upper carbonized nanofiber film, a pressure - sensitive film, and a lower carbonized nanofiber film which are stacked in sequence.

[0046] As a preferred embodiment, the upper carbonized nanofiber film, the pressure - sensitive film, and the lower carbonized nanofiber film have the same thickness.

[0047] In one embodiment, the thin film sensing material is arranged on one or both sensing surfaces of the sensor substrate.

[0048] In one embodiment, as Figure 3 shown, the inner side of the pressure sensor is a rigid sensor substrate, and the sensor films are laid on the top and bottom.

[0049] In one embodiment, the material of the sensor substrate is selected from one or a mixture of PET and stainless steel.

[0050] As a preferred embodiment, as Figure 2 shown, taking the axial direction of the sensor catheter as the longitudinal axis, from left to right are a PET - material substrate, a lower carbonized nanofiber film, a pressure - sensitive film, and an upper carbonized nanofiber film;

[0051] The upper carbonized nanofiber membrane and / or the lower carbonized nanofiber membrane are connected to an intracranial pressure monitor through the sensor wire, as Figure 4 shown. That is, the sensor wire includes at least two electrode wires, which are respectively connected to point A on the lower carbonized nanofiber membrane and point B on the upper carbonized nanofiber membrane (that is, Figure 5 the red dots shown in

[0052] As a preferred embodiment, point A and point B are symmetrically arranged.

[0053] In one embodiment, as Figure 3 shown, the diameter of the sensor catheter is 3 mm, the closed probe end is hemispherical, and three electrode wires are also arranged in the catheter lumen. One end of the electrode wire is connected to the thin film sensing material, and the outside of the electrode wire is a PET material protective layer. The position where the outside of the PET material protective layer contacts the inner wall of the PET material catheter is fixed by ultrasonic welding.

[0054] In one embodiment, the size of the sensor substrate includes: a length of 1 - 5 mm, a width of 0.7 - 3 mm, and a thickness of 0.1 - 0.5 mm; the distance from one end of the sensor substrate close to the probe end is 0.1 - 3 mm.

[0055] As a preferred embodiment, the size of the sensor substrate is selected as a length of 3.5 mm, a width of 2.5 mm, and a thickness of 0.1 mm. That is, the sensing surface is a surface of 3.5 mm * 2.5 mm.

[0056] In one embodiment, the edge of the sensor substrate has a flexible bending structure for complete contact with the inner wall of the sensor catheter.

[0057] As a preferred embodiment, the inner wall material of the sensor catheter is selected from one or a mixture of more than one of TPU, PA, and TPEE; the material of the sensor substrate is selected from one or a mixture of more than one of PET and stainless steel. This combination selection method makes it easy to weld the sensor catheter and the sensor substrate.

[0058] In one embodiment, the outside of the sensor wire is provided with a polymer resin protective layer, and the position where the outside of the polymer resin protective layer contacts the inner wall of the catheter is fixed by ultrasonic welding.

[0059] In one embodiment, the sensor wire segment includes 2 - 4 electrode wires, which are respectively a positive wire, a negative wire, a ground wire, and a function wire, and the positive wire and the negative wire are necessary.

[0060] In one embodiment, the opening angle of the through hole along the circumferential direction of the sensor catheter is: 15° - 60°.

[0061] In one embodiment, the diameter of the sensor catheter is 1 to 3 mm; the size of the through hole in the radial direction of the sensor catheter is 0.5 to 3 mm; the number of through holes is 9 to 36, and the arrangement is (3 to 6) * (3 to 6).

[0062] This application also provides the working process of the intracranial pressure sensor probe that resists intracranial tissue interference: when monitoring intracranial pressure, liquid enters the inner cavity of the sensor catheter, and a pressure sensor is used to perform a pressure-current signal response. As Figure 5 shown, it is a schematic diagram of the working principle of the pressure sensor.

[0063] The principle of pressure detection includes: the upper carbonized nanofiber membrane and the lower carbonized nanofiber membrane are always in contact. When no pressure is applied, due to the self-weight of the device itself, there is an initial current I0. When pressure is applied, since more contact nodes of the carbonized nanofiber membrane come into contact with each other, more conductive paths are formed, and at this time the current signal changes accordingly, increasing to I1, and the external pressure received by the pressure sensor is converted into an electrical signal and reflected. The lead wire is clamped between the two layers of carbonized nanofiber membranes, and any one of them contacts and only contacts one of the upper carbonized nanofiber membrane or the lower carbonized nanofiber membrane, and the external pressure can be converted into an electrical signal. However, after considering the uniformity of pressure induction, the two lead wires are symmetrically arranged on both sides between the upper carbonized nanofiber membrane and the lower carbonized nanofiber membrane, which can better sense the pressure on the surface of the flexible substrate. Combining the pressure sensor with the catheter, there is no need to use secondary catheterization, and intracranial pressure can be directly monitored while draining, effectively avoiding damage to brain tissue and nerve fibers.

[0064] This application also provides a method for ultrasonic welding the inner wall of the sensor catheter and the edge of the sensor substrate, specifically including:

[0065] S1. Place the thin film sensing material connected with the wire and the sensor substrate on a special fixture, attach and fix the thin film sensing material and the sensor substrate with medical glue, and then cure it with a UV ultraviolet light source;

[0066] S2. Move the cured pressure sensor to a position near the end of the inner cavity of the sensor catheter, adjust the position of the pressure sensor to avoid the through holes on the wall of the sensor catheter, so that the flexible bending structures (i.e., Figure 3 the tip protrusions in) on the edges of the sensing surfaces on both sides of the sensor substrate are in complete contact with the inner wall of the catheter;

[0067] S3. Place one side of the end of the probe catheter into the liquid of the ultrasonic welding device, and perform ultrasonic welding to ultrasonically weld and fix the contact surfaces between the two side edges of the sensor substrate, the sensor wire and the inner wall of the catheter to the inner wall of the catheter respectively. After drying, an intracranial pressure sensor probe resistant to intracranial tissue interference is obtained.

[0068] As described above, these are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. An intracranial pressure sensor probe resistant to intracranial tissue interference, characterized in that: It includes a sensor catheter and a closed catheter head, which are fixedly connected to form the end of the sensor probe; The interior of the sensor catheter is provided with a pressure sensor and a sensor wire; the pressure sensor is arranged at a position close to the closed catheter head and is fixedly connected to the inner wall of the catheter; the sensor wire is connected to the pressure sensor; A through hole for drainage is also provided on the tube wall of the sensor conduit near the pressure sensor; The pressure sensor comprises: a sensor substrate, and a sensor membrane having the same size as the sensor substrate; The sensor substrate is arranged axially along the inner cavity of the sensor catheter, and its radial edge is fixedly connected to the inner wall of the catheter; The sensor film is a thin film sensing material covering the sensor substrate; The inner wall material of the sensor catheter includes TPU, PA, and TPEE; The sensor substrate is made of PET and stainless steel.

2. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: The pressure sensor is arranged at a position 1-5 mm away from the closed catheter head.

3. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: The edge of the sensor substrate has a flexible curved structure for completely contacting the inner wall of the sensor tube.

4. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: The dimensions of the sensor substrate include: a length of 1-5 mm, a width of 0.7-3 mm, and a thickness of 0.1-0.5 mm; and a distance of 0.1-3 mm from one end of the sensor substrate close to the probe tip.

5. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: The thin film sensing material comprises an upper carbonized nanofiber membrane, a pressure-sensitive film, and a lower carbonized nanofiber membrane which are stacked in sequence; the upper carbonized nanofiber membrane and the lower carbonized nanofiber membrane are connected to an intracranial pressure monitor via the sensor wire.

6. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: The thin film sensing material is arranged on one or both sides of the sensing surface of the sensor substrate.

7. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: A polymer resin protective layer is arranged on the outside of the sensor wire, and the position where the outside of the polymer resin protective layer contacts the inner wall of the catheter is fixed by ultrasonic welding.

8. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: The opening angle of the through hole along the circumference of the sensor conduit is 15° to 60°.

9. The intracranial pressure sensor probe resistant to intracranial tissue interference according to claim 1, characterized in that: The diameter of the sensor conduit is 1-3 mm; the size of the through hole along the radial direction of the sensor conduit is 0.5-3 mm; the number of the through holes is 9-36, and the arrangement is (3-6)*(3-6).

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