JP2001170013A - Catheter with pressure detection mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter with a pressure detecting function easily manufacturable and smoothly insertable without forming unevenness on the outer surrounding surface of an atmospheric pressure lead-in tube. SOLUTION: The catheter 1 with a pressure detecting function comprises a chip support body 11, a pressure sensor chip 16, a signal wire 39, and an atmospheric pressure lead-in pipe 30. The pressure sensor chip 16 is mounted on the chip support body 11, and the signal wire 39 is electrically connected to the pressure sensor chip 16. The atmospheric pressure lead-in tube 30 makes the atmospheric pressure act on the rear side of the pressure sensor chip 16 as a standard pressure, and the signal wire 39 is inserted into the atmospheric pressure lead-in tube 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter with a pressure detecting mechanism.

[0002]

2. Description of the Related Art Conventionally, a catheter with a pressure detecting mechanism using a pressure sensor chip in a sensor section has been known. There are a relative pressure type and an absolute pressure type as a method of the sensor unit. Here, FIG. 6 shows a conventional example of a catheter with a pressure detection mechanism employing a relative pressure sensor.

A tip support 53 having a columnar shape is attached to the distal end of a catheter tube 52 of the catheter 51. A pressure sensor chip 55 is mounted on a chip mounting portion 54 formed in a concave shape on the upper surface of the chip support 53. Each of the pads formed on the upper surface of the pressure sensor chip 55 is electrically connected to a lead wire at one end of the signal cable 56. The other end of the signal cable 56 is drawn out through the catheter tube 52. In the catheter tube 52, an atmospheric pressure introducing pipe 57 for applying atmospheric pressure as a reference pressure is disposed on the back side of the pressure sensor chip 55. The signal cable 56 is bonded to the entire outer peripheral surface of the pipe 57 in a spirally wound state.

[0004]

However, the above-described prior art in which the signal cable 56 is wound around the pipe 57 and adhered has the following problems.

First, as the outer diameter of the pipe 57 is substantially increased, not only is it difficult to insert the pipe 57 into the catheter tube 52 during assembly, but also the insertability of the tube 52 into the blood vessel is deteriorated. . Secondly, when the tube 52 is inserted, the tube 52 is liable to cause a “twisting phenomenon”, which also deteriorates the insertability into the blood vessel. Third, the operation of winding and bonding the signal cable 56 is very complicated, which makes the manufacture of the catheter 51 difficult. Fourth, since the outer peripheral surface of the pipe 57 has irregularities, the resistance of gas and liquid flowing in the tube 52 increases, and moreover, dirt easily adheres to the outer peripheral surface.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a pressure detecting mechanism which is easy to manufacture and has excellent insertability and which does not cause irregularities on the outer peripheral surface of an atmospheric pressure introducing pipe. It is to provide a catheter.

[0007]

According to the first aspect of the present invention, there is provided a tip support connected to a catheter tube, and a pressure sensor chip mounted on the tip support. And a signal line electrically connected to the pressure sensor chip and drawn out through the catheter tube, and a signal line drawn out through the catheter tube and referenced to the back side of the pressure sensor chip. A catheter having a pressure detection mechanism, characterized in that the signal line is inserted into the atmospheric pressure introducing tube, the catheter having an atmospheric pressure introducing tube for applying atmospheric pressure as pressure.

According to a second aspect of the present invention, in the first aspect, the signal line extends through the through hole provided immediately behind the chip support on the outer peripheral surface of the atmospheric pressure introducing pipe. It is assumed that it has been inserted into the air pressure introduction pipe.

According to a third aspect of the present invention, in the second aspect, the through hole is sealed with an adhesive.
Hereinafter, the “action” of the present invention will be described.

According to the first aspect of the present invention, since the signal line is inserted into the atmospheric pressure introducing pipe, the signal line does not exist on the outer peripheral surface of the atmospheric pressure introducing pipe, and the signal line is wound around the signal line. An increase in the diameter of the pressure introducing pipe is avoided. Therefore, in addition to being able to easily insert the atmospheric pressure introducing tube into the catheter tube at the time of assembly, the insertability of the tube into the blood vessel is improved. In addition, by avoiding the “twist phenomenon” caused by the winding structure, the insertability of the tube into the blood vessel is improved. In addition, the catheter can be easily manufactured because the operation of winding and bonding the signal line becomes unnecessary. Further, since the signal line is inserted into the atmospheric pressure introducing pipe, no irregularities are generated on the outer peripheral surface of the atmospheric pressure introducing pipe, so that an increase in fluid resistance and adhesion of dirt are avoided.

According to the second aspect of the present invention, the signal line is inserted into the atmospheric pressure introducing pipe through the through hole provided immediately behind the chip support on the outer peripheral surface of the atmospheric pressure introducing pipe. The exposure length of the signal line is minimized. Therefore, an increase in the diameter of the atmospheric pressure introducing tube is reliably avoided, and the insertability of the tube into the blood vessel is further improved.

According to the third aspect of the invention, the flow of the fluid inside and outside the atmospheric pressure introducing pipe can be shut off by sealing the through hole with the adhesive. Therefore, for example, it is possible to accurately introduce the atmospheric pressure to the back surface side of the pressure sensor chip. In addition, since the displacement of the signal line is prevented beforehand, the disconnection hardly occurs.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A catheter 1 with a blood pressure detecting mechanism according to an embodiment of the present invention will be described below in detail with reference to FIGS.

A catheter tube 2 constituting the catheter 1 is about 2 mm in diameter and made of polyurethane, and can be inserted into a blood vessel. The proximal end side (not shown) of the catheter tube 2 extends to the outside of the blood vessel (outside the body).

As shown in FIGS. 1 and 2, a tip support block 11 as a tip support, which is a main part of the sensor section, is attached to the distal end side of the catheter tube 2. The chip support block 11 is formed in a substantially cylindrical shape using a ceramic material such as alumina.

The chip support block 11 has a guide hole 3
Are penetrated along the block longitudinal direction. A guide wire (not shown) for guiding the chip support block 11 to a target position in the body is inserted through the guide hole 3. The guide wire is usually withdrawn after the chip support block 11 reaches a target position.

As shown in FIG. 1, a chip support block 1
The diameter of the distal end side and the proximal end side of 1 are each reduced, and connection parts 4 and 5 are formed there, respectively. A cap 6 that covers the opening at the distal end of the guide hole 3 is connected to one connecting portion 4. The cap 6 serves to prevent blood from flowing into the guide hole 3. The other connecting part 5
Is connected to the distal end side of the catheter tube 2 as described above.

Further, in FIG.
The chip housing recess 2
1. A flat portion 22 and a substrate-provided concave portion 23 which constitute a concave portion for disposing a wiring pattern are respectively provided. The chip accommodating recess 21 has a substantially rectangular shape, and the bottom surface is a mounting surface 21 a for the pressure sensor chip 16. Substrate disposition recess 2
3 is shallower than the chip accommodating recess 21. The bottom surface of the flat portion 22 is a substantially rectangular flat surface 22a.

An introduction pipe mounting groove 26 having a substantially U-shaped cross section is formed on the bottom surface of the substrate disposing recess 23 so as to extend along the longitudinal direction of the chip support block 11. An introduction pipe insertion hole 27 having a substantially circular cross section is formed in the base end side region of the flat portion 22 so as to extend along the block longitudinal direction. In the tip side region in the flat portion 22,
An atmospheric pressure introduction hole 28 having a substantially semicircular cross section is formed so as to extend along the block longitudinal direction. An atmospheric pressure introduction groove 29 having a substantially semicircular cross section is formed on the bottom surface of the chip housing recess 21 so as to extend along the longitudinal direction of the chip support block 11. The introduction pipe mounting groove 26 and the atmospheric pressure introduction groove 29 are connected to the introduction pipe insertion hole 27 and the atmospheric pressure introduction hole 2.
8 communicate with each other.

The distal end side of the atmospheric pressure introduction pipe 30 is inserted into and adhered to the introduction pipe insertion hole 27 and the introduction pipe mounting groove 26. Atmospheric pressure introduction pipe 3 of the present embodiment
Numeral 0 is formed in a circular cross section using a material such as stainless steel. It is desirable that the outer peripheral surface of the pipe 30 has a smooth shape without irregularities.

The pipe 30 is disposed in the catheter tube 2, and the proximal end thereof is located in the catheter tube 2.
Has been pulled out of the body. That is, the pipe 3
The base end side of 0 communicates with the atmospheric pressure region, from which air in the atmospheric pressure region is taken.

The mounting surface 21a of the chip receiving recess 21 has
The pressure sensor chip 16 is fixed using an epoxy resin adhesive or the like. It is acceptable to use a silicone resin adhesive instead of the epoxy resin adhesive. As shown in FIG. 3, a recess having a substantially rectangular cross section is formed on the back surface of the pressure sensor chip 16. A space formed below the concave portion is a back pressure chamber 31 communicating with the atmospheric pressure introducing groove 29, and a portion thinned by the concave portion is a diaphragm portion 32. A strain gauge circuit (not shown) is formed on the upper surface of the diaphragm 32. The strain gauge circuit changes the resistance value according to the degree of distortion of the diaphragm 32. This change in the resistance value is output to the outside as an electric signal.

A flexible printed wiring board (hereinafter, referred to as "FPC") 17 is placed on and adhered to the flat surface 22a of the flat portion 22 and the bottom surface of the substrate mounting concave portion 23. On the upper surface of the FPC 17, a plurality (five) of wiring patterns 36 are formed in parallel along the longitudinal direction of the wiring board. The FPC 17 is bent at the center so as to follow the shapes of the flat portion 22 and the recess 23 provided on the substrate.

At the base end portion on the upper surface side of the pressure sensor chip 16, five pad portions electrically connected to the strain gauge circuit are arranged. These pads and FPC1
The respective wiring patterns 36 are bonded via, for example, bonding wires 37 made of gold. Such a bonding portion is sealed with, for example, a silicone rubber sealant 38.

As shown in FIG. 1, FIG. 2, FIG.
A distal end side of a signal cable 39 as a signal line is mounted on a base end portion on an upper surface side of the PC 17. The signal cable 39 of the present embodiment has a structure in which a plurality (five) of lead wires 39a are bundled. Each lead wire 39a is individually branched on the distal end side of the signal cable 39. These lead wires 39a are soldered to the base ends of the corresponding wiring patterns 36, respectively. The branch portion of the signal cable 39 is connected to the FPC 1
7 is fixed to the base end on the upper surface side.

The distal ends of the pressure sensor chip 16 and the FPC 17 are sealed with a sealant 41 made of a biocompatible material such as silicone rubber. As a result, the pressure sensor chip 16 and the bonding portion are protected. Therefore, the pressure in the outer peripheral region of the catheter 1 does not directly act on the upper surface side of the diaphragm portion 32, but acts indirectly via the sealant 41 thereon. The back pressure chamber 31 has an atmospheric pressure introduction groove 2.
9. The atmospheric pressure introduced via the atmospheric pressure introduction hole 28 and the atmospheric pressure introduction pipe 30 acts as a reference pressure.

A through hole 42 is provided on the outer peripheral surface of the atmospheric pressure introducing pipe 30 immediately behind the chip support block 11 (specifically, in this embodiment, at a position within 1 cm from the rear end surface of the chip support block 11). ing. And, as shown in FIG.
2 and is inserted into the atmospheric pressure introduction pipe 30 via the air inlet 2.
In this case, it is necessary to secure a gap 43 between the inner peripheral surface of the pipe 30 and the outer peripheral surface of the signal cable 39 to allow air to flow. Therefore, the cross-sectional area of the signal cable 39 is set to be smaller than at least the cross-sectional area of the pipe 30. Signal cable 3 inserted in pipe 30
The base end side of 9 is pulled out of the body via a pipe 30 and is electrically connected to an external circuit (not shown). In addition, the through hole 42 in the present embodiment has an elliptical shape that is long along the longitudinal direction of the atmospheric pressure introduction pipe 30 to facilitate insertion of the signal cable 39. When the signal cable 39 is inserted, the through-hole 42 is entirely sealed by the adhesive 44.
As a result, the flow of the fluid inside and outside the pipe 30 through the through hole 42 is shut off, and the signal cable 39 is fixed to the opening edge of the through hole 42.

When the thus constructed catheter 1 is inserted into a blood vessel, the outer surface of the sealant 41
The pressing force according to the blood pressure value always acts. On the other hand, the atmospheric pressure is acting on the back pressure chamber 31 communicating with the atmospheric pressure region.

In this state, if the blood pressure rises, for example, the force for pressing the outer surface of the sealant 41 also increases, and the force for pressing the diaphragm 32 via the sealant 41 also increases. As a result, the distortion of the diaphragm section 32 increases, and the resistance value of the strain gauge circuit formed on the diaphragm section 32 changes. The change in the electric signal based on the change in the resistance value is output to an external circuit (not shown) via the bonding wire 37, the wiring pattern 36, and the signal cable 39.

Therefore, according to the present embodiment, the following effects can be obtained. (1) In the catheter 1 of the present embodiment, the signal cable 3
9 is inserted into the atmospheric pressure introduction pipe 30. Therefore, unlike the conventional signal wire winding structure, the signal cable 39 does not exist on the outer peripheral surface of the pipe 30. For this reason, it is possible to avoid an increase in the diameter of the atmospheric pressure introduction pipe 30 due to the signal line winding structure. Therefore, the pipe 30 can be easily inserted into the catheter tube 2 at the time of assembly. In addition, the insertion property of the catheter tube 2 into a blood vessel is also improved. The "twist phenomenon" caused by the signal wire winding structure is also avoided,
This also improves the insertability of the catheter tube 2 into the blood vessel.

(2) According to the catheter 1 of the present embodiment, the catheter 1 can be easily manufactured because the operation of winding the signal cable 39 and adhering the entire cable becomes unnecessary. Also, cost reduction can be achieved.
Further, since the signal cable 39 is inserted into the atmospheric pressure introducing pipe 30, no irregularities are formed on the outer peripheral surface of the pipe 30. Therefore, an increase in resistance of a drug solution or the like flowing in the catheter tube 2 is avoided, and attachment of dirt to the outer peripheral surface is also avoided.

(3) In this catheter 1, a through hole 42 is provided on the outer peripheral surface of the atmospheric pressure introducing pipe 30 immediately behind the chip support block 11. The signal cable 39 is inserted into the atmospheric pressure introduction pipe 30 through the through hole 42. Therefore, the signal cable 3
9 is minimized, and almost the entire signal cable 39 is housed in the pipe 30 except for the distal end. Therefore, the increase in the diameter of the atmospheric pressure introducing pipe 30 is reliably avoided, and the insertability of the catheter tube 2 into the blood vessel can be further improved.

(4) In this catheter 1, the through-hole 42 is sealed with the adhesive 44 when the signal cable 39 is inserted. Therefore, the flow of the fluid inside and outside the atmospheric pressure introduction pipe 30 can be shut off. Therefore, it is possible to accurately introduce the atmospheric pressure to the back surface side of the pressure sensor chip 16, and the measurement accuracy of the blood pressure is improved.

In addition, as a result of the signal cable 39 being fixed to the opening edge of the through hole 42, the displacement of the signal cable 39 can be prevented beforehand. For this reason, the disconnection of the lead wire 39a hardly occurs, and the reliability of the device is reliably improved. The fact that the entire signal cable 39 is protected by the pipe 30 also contributes to the prevention of disconnection.

The embodiment of the present invention may be modified as follows. When the signal cable 39 is less likely to be exposed to a liquid such as a medicine, the through hole 42 in the pipe 30 does not necessarily need to be sealed with the adhesive 44.

The through hole 42 is provided in the chip support block 1
It may not be provided immediately behind 1 and may be provided at a position separated from the chip support block 11 to some extent.

The signal cable 39 may be inserted from the opening at the tip of the pipe 30. In other words, it is also possible to adopt a configuration in which the through hole 42 is omitted. The signal line does not necessarily have to be in the form of a cable as in the embodiment, and may be, for example, a long structure integrally formed with the FPC 17.

FPC 17 used in the embodiment
Alternatively, a rigid substrate may be used instead. A configuration in which a printed wiring board such as the FPC 17 is omitted, and each lead wire 39a is directly joined to a pad may be adopted.

The material of the chip support block 11 is not limited to alumina as in the embodiment, but may be another ceramic such as zirconia. Further, a material other than the ceramic material, for example, a metal such as stainless steel, plastic, or the like may be used. in short,
Any material having a small coefficient of thermal expansion and biocompatibility can be selected as the block forming material.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments will be listed below. (1) In any one of claims 1 to 3, the atmospheric pressure introducing pipe has a substantially circular cross section, and its outer peripheral surface has a smooth shape without irregularities.

(2) A tip support connectable to a catheter tube, a pressure sensor chip mounted on the tip support, a signal line electrically connected to the pressure sensor chip, and the pressure sensor chip And a pressure introducing pipe for applying atmospheric pressure as a reference pressure on the back side of the module, wherein the signal line is inserted into the atmospheric pressure introducing pipe.

(3) A tip support having a connection portion connectable to the tip of the catheter tube, a pressure sensor chip mounted on the tip support, and a signal line electrically connected to the pressure sensor chip And a pressure-introducing pipe for applying atmospheric pressure as a reference pressure on the back side of the pressure sensor chip, wherein a through-hole is provided on the outer peripheral surface of the atmospheric-pressure introducing pipe immediately behind the chip support. Wherein the signal line is inserted into the atmospheric pressure introducing pipe through the via hole, and the through-hole is sealed with an adhesive in that state.

[0043]

As described above in detail, according to the first to third aspects of the present invention, the pressure is high, which is easy to manufacture, has excellent insertability, and does not cause unevenness on the outer peripheral surface of the atmospheric pressure introducing pipe. A catheter with a detection mechanism can be provided.

According to the second aspect of the invention, the insertability of the tube into the blood vessel can be further improved. According to the third aspect of the invention, measurement accuracy and reliability can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a sensor unit of a catheter according to an embodiment of the present invention.

2A is a partial plan view of a sensor unit, and FIG. 2B is a cross-sectional view taken along line AA in FIG.

FIG. 3 is a sectional view taken along line BB in FIG. 2 (b).

FIG. 4 is a sectional view taken along line CC in FIG. 2 (b).

FIG. 5 is a sectional view taken along line DD in FIG. 2 (b).

FIG. 6 is a schematic sectional view showing a sensor section of a conventional catheter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Catheter with a pressure detection mechanism, 2 ... Catheter tube, 11 ... Tip support block as tip support, 16 ... Pressure sensor chip, 30 ... Atmospheric pressure introduction pipe as atmospheric pressure introduction pipe, 39 ... Signal as signal line Cable, 42: through hole, 44: adhesive.

Continuation of the front page (72) Inventor Kiyoshi Koide 3-260 Toyota, Oguchi-machi, Niwa-gun, Aichi Prefecture Inside Tokai Rika Electric Works, Ltd. Zeon Medical Co., Ltd. Laboratory F-term (reference) 4C017 AA08 AB10 AC03 EE03

Claims (3)

[Claims] 1. A tip support connected to a catheter tube, a pressure sensor chip mounted on the tip support, and electrically connected to the pressure sensor chip and externally connected via the catheter tube. A signal line that is drawn out to the catheter tube, which is drawn out to the outside via the catheter tube, and has an atmospheric pressure introducing pipe that applies atmospheric pressure as a reference pressure to the back side of the pressure sensor chip. A catheter with a pressure detection mechanism, which is inserted into an atmospheric pressure introducing pipe. 2. The signal line according to claim 1, wherein the signal line is inserted into the atmospheric pressure introducing pipe through a through hole provided immediately behind the chip support on the outer peripheral surface of the atmospheric pressure introducing pipe. The catheter with a pressure detection mechanism according to claim 1. 3. The catheter with a pressure detecting mechanism according to claim 2, wherein the through hole is sealed with an adhesive.