JPH0515288Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a device that is pressed against the surface of a human body and detects pulse waves generated from arteries within the human body.
In particular, the present invention relates to a pulse wave detection device that has a simple structure and is inexpensive.

PRIOR ART Pressure waves or vibrations of the arterial wall that are generated with the heart's beats and propagate in the arteries are generally called pulse waves, and these pulse waves can be used to determine various medical information such as the state of cardiac motion. It is known that information can be obtained. As a device for detecting such pulse waves, a pressure sensor equipped with a strain gauge, a piezoelectric element, etc. is pressed against the surface of the human body, and the pressure vibrations of the pulse waves generated from the arteries in the human body are detected. There is something I did. For example, the device described in Japanese Utility Model Application Publication No. 61-60901 is one example.

However, in order to detect pulse waves by pressing a pressure sensor against the surface of the human body, it is necessary to arrange the pressure sensor's strain gauge, piezoelectric element, etc. in a special manner, making the device complicated. The problem was that it was expensive.

To solve this problem, we developed a device that detects pressure fluctuations in pulse waves as pressure fluctuations in a pressure chamber due to changes in the volume of a sealed fluid.
By combining the technology described in Japanese Utility Model Application Publication No. 133003 and the technology described in Japanese Utility Model Application Publication No. 59-111108, which detects pressure vibrations of pulse waves through an elastically deformable diaphragm, (a) (b) a container disposed at the opening of the container to form an airtight pressure chamber within the container; (c) an elastically deformable diaphragm that vibrates in accordance with the pressure vibration of the pulse wave by being pressed against the body surface of the human body with a pressing force corresponding to the pressure of the gas; (c) connected to the pressure chamber; It may be possible to obtain a pulse wave detection device including a pressure sensor that detects pressure fluctuations within the pressure chamber due to changes in the volume of the pressure chamber due to vibrations of the diaphragm. According to this, the volume inside the pressure chamber is changed by the vibration of the diaphragm pressed against the surface of the human body, and the pressure fluctuation accompanying this volume change is detected by the pressure sensor, so that the distortion This has the advantage that the device can be constructed simply and at low cost compared to the case where a gauge, piezoelectric element, etc. are directly disposed on the surface of the human body.

Problems to be solved by this invention By the way, when actually detecting a pulse wave with the above-mentioned pulse wave detection device, the pressure vibration of the pulse wave is vibrated with a pressing force that optimally reflects the volume change in the pressure chamber. It is necessary to press the plate against the surface of the human body. If the pressing force is too small than the optimum pressing force, the pressure vibration within the pressure chamber will be small and it will be difficult to detect the pulse wave, and if it is too large, changes in the pressure vibration of the pulse wave will be distorted and detected. The optimal pressing force of the diaphragm for detecting pulse waves as described above differs for each human body depending on the thickness of the artery and the depth from the body surface to the arterial wall. It is required that the optimum pressing force be individually set accordingly. On the other hand, the above-mentioned pulse wave detection device does not have a means to adjust the pressing force of the diaphragm so that the pressing force is optimal. Due to the lack of pressure, pulse waves were sometimes not accurately detected from pressure fluctuations within the pressure chamber.

The present invention was developed against the background of the above-mentioned circumstances, and its purpose is to create a pulse wave system in which the pulse wave can be accurately detected by pressing the diaphragm with the optimal pressing force for each subject. An object of the present invention is to provide a wave detection device.

Means for Solving the Problems To achieve the above object, the gist of the present invention is a device that detects pulse waves generated from arteries in the human body when pressed against the surface of the human body, (a) a container disposed with an opening facing the body surface of the human body; and (b) a container provided at the opening of the container to form an airtight pressure chamber within the container; (c) an elastically deformable diaphragm that vibrates in accordance with the pressure vibration of the pulse wave by being pressed against the body surface of the human body with a pressing force corresponding to the pressure of the gas filled in the pressure chamber; (d) a pressure sensor that is connected to the diaphragm and outputs a pressure signal by detecting pressure fluctuations in the pressure chamber due to changes in the volume of the pressure chamber due to vibrations of the diaphragm; and a pressing force adjusting means for adjusting the pressing force of the diaphragm so that the pressing force of the diaphragm is optimized based on the above-mentioned.

Function and Effect of the Invention By doing this, when actually detecting a pulse wave, the pressing force adjustment means adjusts the pressing force of the diaphragm to be optimal based on the pressure signal from the pressure sensor. Pressure is regulated. Therefore, according to the pulse wave detection device of the present invention, the pulse wave is detected based on the volume change in the pressure chamber that optimally reflects the pressure vibration of the pulse wave for each subject, and the pulse wave is accurately detected. detected.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference

In FIGS. 1 and 2, 10 is a support plate attached to a human wrist 16 by a pair of bands 12,14. This support plate 10 has a dogleg shape and is attached to the outside of the wrist 16, so as to hold the wrist 16 in a substantially constant posture with the wrist 16 bent outward. This is because when the wrist 16 is bent outward, the radial artery 18 passing inside the wrist 16 stands out on the body surface 20, making it easier to detect pulse waves from the radial artery 18.

Four pins 22 are erected on the support plate 10 in parallel to each other at substantially right angles to the wrist 16, and a frame 24 is attached to these pins 22. The frame body 24 is made of a relatively rigid material, and is bent so that it can be wrapped around the wrist 16 from the outside to the inside without contacting the wrist 16. One end 26 located on the outside thereof is attached to the pin 22 so as to be movable in a direction substantially perpendicular to the wrist 16 as indicated by arrow A in FIG. Also,
Between the one end portion 26 and the support plate 10, there is an expansion bag 32 made of rubber that is inflated by supplying a pressure fluid such as pressure air or water from the fluid supply device 28 through a pipe 30. When the expansion bag 32 is inflated, the frame 24 is moved downward in FIG. Each of the pins 22 is provided with a large-diameter head at its tip to prevent the frame 24 from being pulled out.

On the other hand, the other end of the frame 24, that is, the wrist 1
A container 36 having a cylindrical shape with a bottom is provided at an end 34 located on the opposite side of the one end 26 across the container 6 . As shown in FIG. 3, this container 36 is fixed to the other end 34 with an opening 38 facing the body surface 20, and a diaphragm 40 is attached to the opening 38. It is being
The diaphragm 40 is an elastically deformable diaphragm 4 in the shape of a disk whose outer peripheral edge is fixed to the opening 38.
2 and a disk-shaped plate member 44 fixed to substantially the entire surface of the diaphragm 42 except for the outer periphery, and by fixing the diaphragm 42 to the opening 38, the inside of the container 36 is airtight. A pressure chamber 46 is formed. This pressure chamber 46 is filled with air in advance so that the diaphragm 40 is bulged out from the opening 38, and the pressure chamber 46 is communicated with a pressure sensor 50 via a pipe 48. The pressure sensor 50 detects the pressure within the pressure chamber 46 using a strain gauge, a piezoelectric element, or the like with reference to atmospheric pressure, and has a well-known structure. Also,
The plate member 44 is made of a relatively rigid material, and restricts the elastic deformation of the diaphragm 42 and displaces the diaphragm 42 as a whole. A small diameter contactor 52 is provided.

In the pulse wave detection device configured as described above, the support plate 10 is attached to the wrist 16 so that the contact 52 is located directly above the radial artery 18. In this state, when pressure fluid is supplied from the fluid supply device 28 into the expansion bag 32 and the frame body 24 is moved downward in FIG. 2, the contactor 52 comes into contact with the body surface 20 and 40 to the container 36 side. This results in
The volume of the pressure chamber 46 is reduced and the internal pressure is increased, and the contact 52 and the diaphragm 40 are pressed against the body surface 20 according to the internal pressure.

When the contact 52 is pressed against the body surface 20, the contact 52 is vibrated together with the diaphragm 40 due to the pressure vibration of the pulse wave generated from the radial artery 18, and this vibration causes the pressure chamber 46 to vibrate. When the volume changes, the internal pressure also changes, and this pressure change is detected by the pressure sensor 50. The pressure fluctuation within the pressure chamber 46 corresponds to the pressure vibration of the pulse wave,
Thereby, a pulse wave generated from the radial artery 18 is detected. Note that the pressure of the pressure fluid supplied from the fluid supply device 28 into the expansion bag 32 is determined based on the electrical signal output from the pressure sensor 50, and the pressure of the pressure fluid is adjusted to the optimal pressing force for detecting the pulse wave. 52 is adjusted to press against the body surface 20.

That is, based on the pressure signal output from the pressure sensor 50, the pressing force is adjusted so that, for example, the amplitude of the pulse wave is maximized.

As described above, in the pulse wave detection device of this embodiment, the volume inside the pressure chamber 46 is changed by the contactor 52 pressed against the body surface 20 being vibrated together with the diaphragm 40, and the volume change The pressure sensor 50 connected to the pressure chamber 46 in the container 36 detects the pressure fluctuation caused by the
It is now possible to use a commercially available pressure sensor 50 as is, and compared to the case where a strain gauge, piezoelectric element, etc. are provided on the diaphragm 40,
The pulse wave detection device can be constructed easily and inexpensively.

Furthermore, since the diaphragm 40 is made to vibrate as a whole by the plate member 44,
Even if the displacement of the diaphragm 40 accompanying the pressure vibration of the pulse wave is small, the change in volume of the pressure chamber 46 and further the pressure fluctuation are relatively large, and the pressure vibration of the pulse wave can be easily detected.

Furthermore, in the pulse wave detection device of this embodiment, the fluid supply device 28 and the expansion bag 32, which correspond to the pressing force adjustment means, optimize the pressing force of the diaphragm 40 based on the pressure signal from the pressure sensor 50. The pressing force is adjusted accordingly. Therefore, according to the pulse wave detection device of this embodiment, the pulse wave is detected based on the volume change in the pressure chamber 46 that optimally reflects the pressure vibration of the pulse wave for each subject. Waves are detected accurately.

Next, another embodiment of the present invention will be described. In addition,
In the following embodiments, parts common to those in the above embodiments are given the same reference numerals and explanations will be omitted.

In FIG. 4, the container 36 is attached to the wrist 16 by a pair of flexible attachment belts 60, 62. These attachment belts 60 and 62 are wrapped around the wrist 16 so that the contactor 52 is positioned directly above the radial artery 18, and are removably locked to each other at their distal ends. Further, a pressure air supply device 64 corresponding to a pressing force adjusting means is connected to the piping 48,
By supplying pressurized air into the pressure chamber 46, the contact 52 is pressed against the body surface 20. In this case, the pressure chamber 46 also functions as the expansion bag 32, making the device simpler and cheaper.

Although the embodiments of the present invention have been described above in detail based on the drawings, the present invention can also be implemented in other embodiments.

In the above embodiment, the plate member 44 is attached to the diaphragm 42.
However, it is also possible to provide the contact 52 directly on the diaphragm 42 without providing the plate member 44, or to press the diaphragm 42 directly against the body surface 20.

Further, in the embodiment described above, pressure fluid is supplied into the expansion bag 32 to press the contact 52 against the body surface 20, but it is also possible to use a cylinder, a spring, etc. as the pressing force adjustment means. . The frame 24 is fixed to the support plate 10, and the container 36 is movably disposed at the other end 34 of the frame 24, so that the container 36 is placed on the body surface relative to the other end 34. 20 may be moved in the direction closer to 20.

Further, although the diameter of the contactor 52 in the embodiment described above is smaller than the diameter of the radial artery 18, it is also possible to use a contactor having a diameter larger than the diameter of the artery 18.

Further, in the above embodiment, the radial artery 18 of the wrist 16
Although a pulse wave detection device that detects pulse waves from the carotid artery has been described, the present invention can be similarly applied to detect pulse waves from other arteries such as the carotid artery.

Further, in the embodiment described above, the pressure inside the pressure chamber 46 is detected by the pressure sensor 50 using atmospheric pressure as a reference, but when measuring the blood pressure value based on the detected pulse wave, for example, Showa 62-
As described in Publication No. 72605, a liquid with approximately the same specific gravity as blood, placed so that the liquid level is at the same height as the heart, is guided to a pressure sensor (differential pressure gauge), and the pressure is measured based on the pressure of the liquid. It is also possible to detect the pressure within the chamber 46. In that case, fluctuations in blood pressure values due to a difference between the pulse wave detection position and the heart height position are prevented.

Although no other examples are given, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a state in which a pulse wave detection device according to an embodiment of the present invention is attached to a wrist. FIG. 2 is a sectional view of FIG. 1. FIG. 3 is a cross-sectional view of the container shown in FIG. 2. FIG. 4 is a diagram illustrating the main part of another embodiment of the present invention. 18...Radial artery, 20...Body surface, {28...
...fluid supply device, 32 ... expansion bag} (pushing force adjustment means), 36 ... container, 38 ... opening, 40 ...
... Vibration plate, 46 ... Pressure chamber, 50 ... Pressure sensor, 64 ... Pressure air supply device (pressing force adjustment means).

Claims (1)

[Claims for Utility Model Registration] (1) A device for detecting pulse waves generated from an artery in the human body when pressed against the surface of the human body, with an opening facing the surface of the human body. a container provided at the opening of the container to form an airtight pressure chamber within the container, and a pressing force corresponding to the pressure of the gas filled in the pressure chamber to press the surface of the human body. an elastically deformable diaphragm that vibrates in accordance with the pressure vibration of the pulse wave when pressed by the pressure chamber; a pressure sensor that detects pressure fluctuations in the pressure chamber and outputs a pressure signal; and a pressing force that adjusts the pressing force of the diaphragm so that the pressing force of the diaphragm is optimal based on the pressure signal from the pressure sensor. A pulse wave detection device comprising: an adjusting means; (2) The diaphragm includes an elastically deformable diaphragm provided in the opening, and is fixedly installed on substantially the entire surface of the diaphragm to restrict elastic deformation of the diaphragm. 2. The pulse wave detection device according to claim 1, which is a device comprising a highly rigid plate member that vibrates the diaphragm as a whole.