JPH09168514A - Medical pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reference value as well as detected value of a sensor chip from fluctuating even if a catheter bends. SOLUTION: In a lumen 12a of a catheter 11, a pressure detection sensor chip 15 mounted on a base 16 is disposed. A base 16 is of a box shape which has a rectangular frame-shaped surrounding wall 16a surrounding the sensor chip 15. Even if the catheter 11 bends, the base 16 is difficult to deform, so, bending stress applied to the sensor chip 15 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical pressure sensor having a structure in which a sensor chip for pressure detection is arranged inside a catheter inserted into a living body in order to measure pressure such as blood pressure.

[0002]

FIG. 4 and FIG. 5 show an example of a conventional structure of a medical pressure sensor of this type. The catheter 1 has a tubular shape with a diameter of about 2 mm, and two lumens 2a and 2b are formed inside by a partition wall 1a. One lumen 2 of the lumens 2a and 2b
The tip of a (the left end in FIG. 4) is closed. The other end of the lumen 2b is open, so that blood or the like can flow inside. A mounting opening 3 is formed in a portion of the peripheral wall of the catheter 1 corresponding to the lumen 2a, and a detection opening 4 is formed in a predetermined portion of the partition wall 1a.

The sensor chip 5 for pressure detection is a base 6
It is mounted in the one lumen 2a through the mounting opening 3. The base 6 is made of, for example, silicon, has convex portions 6a and 6b at both ends, and the sensor chip 5 is arranged between these convex portions 6a and 6b. A relay plate 7 is adhered to the lower surfaces of the both convex portions 6a and 6b of the base 6 in the figure, and the electrode terminals of the sensor chip 5 are connected via the lead patterns formed on the relay plate 7,
The lead wire 8 inserted in the lumen 2a is electrically connected. The relay plate 7 has an opening 7a formed in a portion corresponding to the pressure receiving portion 5a of the sensor chip 5.

The sensor chip 5 and the base 6 are connected to the relay plate 7
The pressure receiving portion 5a of the sensor chip 5 faces the detection opening 4 of the partition wall 1a in this mounted state. The detection opening 4 is sealed with silicone rubber 9, and the mounting opening 3 is
Thin-walled tube 10 mounted on the outer periphery of the catheter 1
Are covered by.

In the case of such a structure, the catheter 1 is inserted into, for example, a blood vessel of a living body, and the pressure of blood flowing in the lumen 2b is received by the pressure receiving portion 5a of the sensor chip 5 via the silicone rubber 9. The sensor chip 5 converts into an electric signal according to the received pressure, and the electric signal is output via the lead wire 8.

By the way, in such a structure, when the catheter 1 is inserted into a blood vessel, for example, the catheter 1 needs to bend along the blood vessel. At this time, if the catheter 1 bends particularly in the direction of arrow A in FIG. 4,
There is a problem that the sensor chip 5 receives the stress caused by the bending, and the reference value of the sensor chip 5 and thus the detected value may fluctuate.

Therefore, an object of the present invention is to provide a medical pressure sensor capable of preventing the reference value of the sensor chip, and hence the detected value, from varying even if the catheter bends.

[0008]

In order to achieve the above object, the present invention provides a sensor chip mounted on a base inside a catheter, and the pressure received by a pressure receiving portion of the sensor chip is electrically applied. In the medical pressure sensor configured to convert into a signal and output the signal, the base is a box type having a surrounding wall surrounding the sensor chip.

According to such means, the base to which the sensor chip is attached is in the form of a box having a surrounding wall and is in a form which is difficult to be deformed by bending stress, so that the catheter bends. Also, the bending stress applied to the sensor chip can be relaxed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. First, in FIGS. 1 and 2, the catheter 11 has a tubular shape with a diameter of about 2 mm as in the conventional configuration, and two lumens 12a and 12b are formed inside by a partition wall 11a. One of the lumens 12a and 12b has a distal end (left end in FIG. 1) closed. Further, the distal end of the other lumen 12b is open so that blood or the like can flow inside.
A mounting opening 13 is formed in a portion of the peripheral wall of the catheter 11 corresponding to the lumen 12a, and the partition wall 11
A detection opening 14 is formed at a predetermined portion of a.

The pressure detecting sensor chip 15 converts the pressure received by the pressure receiving portion 15a into an electric signal and outputs the electric signal. In the state of being attached to the base 16, one lumen 12a is passed through the mounting opening 13. It is arranged inside.

Here, the base 16 is made of, for example, ceramic and has a rectangular frame-shaped surrounding wall 16a surrounding the sensor chip 15, as shown in FIG. The sensor chip 15 is housed in the surrounding wall 16 a, and the lower surface in FIG. 3 is fixed to the inner surface of the base 16.

A relay plate 17 made of a film substrate is adhered to the lower surface of the surrounding wall 16a of the base 16 in FIG. 1 (the upper surface of the surrounding wall 16a in FIG. 3).
The electrode terminal (not shown) of the sensor chip 15 and the lumen 1 via the lead pattern (not shown) formed in
The lead wire 18 inserted in 2a is electrically connected. The relay plate 17 includes a pressure receiving portion 1 of the sensor chip 15.
An opening 17a is formed in a portion corresponding to 5a.

The sensor chip 15 and the base 16 are attached to the partition wall 11a via a relay plate 17,
In this mounted state, the pressure receiving portion 15a of the sensor chip 15 faces the detection opening 14 of the partition wall 11a. The detection opening 14 is sealed with silicone rubber 19, and the mounting opening 13 is covered with a thin tube 20 attached to the outer peripheral portion of the catheter 11 after mounting the sensor chip 15 and the base 16. It has become.

In the case of such a structure, similarly to the conventional structure, the catheter 11 is inserted into, for example, a blood vessel of a living body, and the pressure of blood flowing in the lumen 12b is received by the sensor chip 15 via the silicone rubber 19. The sensor chip 15 receives it at the portion 15a, converts it into an electric signal corresponding to the received pressure, and outputs the electric signal via the lead wire 18.

When the catheter 11 is inserted into a blood vessel of a living body, even if the catheter 11 bends in the direction of arrow A in FIG. 1, the base 16 to which the sensor chip 15 is attached has a surrounding wall 16a. Since it has a box shape and is not easily deformed by bending stress, the bending stress applied to the sensor chip 15 can be relaxed.
Moreover, in this case, the adhesive region between the base 16 and the partition wall 11a of the catheter 11 is the pressure receiving portion 1 of the sensor chip 15.
Since it surrounds the entire circumference of the surrounding wall 16a that surrounds 5a, it is possible to more reliably prevent deformation around the pressure receiving portion 15a. Therefore, even if the catheter 11 bends, the bending stress applied to the sensor chip 15 can be relieved, so that the reference value of the sensor chip 15, and thus the detected value, can be prevented from varying.

Further, in the above-mentioned embodiment, since the base 16 is made of ceramic, the electric insulation can be improved, and the base 16 can be manufactured by the die working (molding), so that it can be manufactured at a relatively low cost. .

The present invention is not limited to the above-mentioned embodiments, but can be modified or expanded as follows. For example, the base 16 is not limited to ceramic, but may be synthetic resin or stainless steel. Further, the mounting opening 13 of the catheter 11 may be a slit as long as the sensor chip 15 and the base 16 can be mounted in the catheter 11.

Further, in this embodiment, two lumens 1 are used.
Although the present invention is applied to the catheter 11 formed of 2a and 12b, the present invention is not limited to this and can be applied to a catheter having three or more lumens.

[0020]

As is apparent from the above description, according to the medical pressure sensor of the present invention, since the base to which the sensor chip is attached is box-shaped, even if the catheter is bent, the reference value of the sensor chip, As a result, there is an excellent effect that the detected value can be prevented from fluctuating.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a main part showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II in FIG.

FIG. 3 is a perspective view of a sensor chip and a base.

FIG. 4 is a diagram corresponding to FIG. 1 showing a conventional example.

5 is a cross-sectional view taken along the line of FIG.

[Explanation of symbols]

11 is a catheter, 15 is a sensor chip, 15a is a pressure receiving portion, 16 is a base, 16a is a surrounding wall, 17 is a relay plate, 1
Reference numeral 8 is a lead wire.

Claims (1)

[Claims] 1. A medical pressure sensor having a structure in which a sensor chip attached to a base is provided inside a catheter, and pressure received by a pressure receiving portion of the sensor chip is converted into an electric signal and output. A medical pressure sensor, characterized in that the base is a box type having a surrounding wall surrounding the sensor chip.