WO2022215645A1

WO2022215645A1 - Biological information detection device and seating assessment device

Info

Publication number: WO2022215645A1
Application number: PCT/JP2022/016498
Authority: WO
Inventors: 松田勲; 青木洋一; 堀内裕城
Original assignee: 太陽誘電株式会社
Priority date: 2021-04-05
Filing date: 2022-03-31
Publication date: 2022-10-13
Also published as: JPWO2022215645A1

Abstract

This biological information detection device is provided with: a bag-shaped first member which is filled with air and which has a first surface and a second surface facing one another; a bag-shaped second member which is filled with air and which has a third surface and a fourth surface facing one another, the third surface facing the second surface; a module provided with a first pusher that is located at the center of the first surface as seen from the direction of stacking of the first member and the second member, and a second pusher that is in contact with at least the center of the fourth surface; and a detector for detecting the difference between the gas pressure inside the first member and the gas pressure inside the second member. The distance between the first surface and a fifth surface, which is a surface of the first pusher and faces the first surface, decreases going from the peripheral edge toward the center. Vibrations can be transmitted between the first surface and the fifth surface.　

Description

Biological information detection device and seating determination device

The present invention relates to a biological information detection device and a seating determination device, and for example, to a biological information detection device and a seating determination device that detect vital vibrations.

　Biological information detection devices are known that detect vibrations of human vitals such as pulse waves and respiration (for example, Patent Documents 1 to 6). It is known to detect vibrations of vital signs by using a bag-shaped member containing air and detecting the pressure of the air in the bag-shaped member (for example, Patent Document 4 and 5).

JP 2017-219341 A Japanese Patent Application Laid-Open No. 2006-218068 JP-A-2006-42904 JP 2018-47862 A JP 2009-82585 A JP 2009-104599 A

However, highly sensitive vibration detectors are susceptible to external vibrations. For example, large disturbance vibration such as drive noise occurs while the vehicle is running. When the output signal of a sensor element that detects vibration is amplified and converted into an analog voltage, the signal becomes saturated. This is because the output of the amplifier is within the range of the power supply voltage, so if the output signal of the sensor element is large, the amplified signal exceeds the range of the power supply voltage. When the signal saturates, it becomes impossible to detect minute vital vibrations inherent in large vibrations.

The present invention has been made in view of the above problems, and aims to improve detection accuracy.

The present invention has a bag-shaped first member having first and second surfaces facing each other and filled with gas, and third and fourth surfaces facing each other, the third surface being A bag-like second member that faces the second surface and is filled with gas; and a first pressing portion that is positioned in the center of the first surface when viewed from the stacking direction of the first member and the second member. and a second pressing portion in contact with at least a central portion of the fourth surface; a detector for detecting a difference between the gas pressure in the first member and the gas pressure in the second member; , the distance between the first surface and the fifth surface of the first pressing portion facing the first surface decreases from the peripheral portion toward the central portion, and the first surface and the first A biometric information detection device is capable of transmitting vibration between the five surfaces.

In the above configuration, the surface of the first pressing portion facing the first surface may be configured such that the central portion protrudes toward the first surface from the peripheral portion.

In the above configuration, the first surface may have a configuration in which the central portion protrudes toward the first pressing portion with respect to the peripheral portion.

In the above configuration, the second surface and the third surface may be in contact with each other.

In the above configuration, the module includes a separator provided between the second surface and the third surface so as to be in contact with the peripheral edge portions of the second surface and the third surface, and the separator causes the second surface to and the third surface can be configured to be separated from each other.

In the above configuration, the module may include a support member that surrounds the first member and the second member and connects the first pressing portion and the second pressing portion.

In the above configuration, the module includes a plate-like member provided on the opposite side of the first pressing portion from the first pressing portion and away from the first pressing portion; A shaft core member connected to the central portion of the first pressing portion and having a plane area smaller than that of the plate member may be provided.

In the above configuration, the first surface, the second surface, the third surface and the fourth surface may be arranged in a direction substantially perpendicular to the vertical direction.

In the above configuration, the module includes: a third member provided on the side opposite to the first member with respect to the first pressing portion; a third pressing portion located at the peripheral portion and in contact with the first surface and the third member, wherein vibration can be transmitted between the first surface and the third member via the first pressing portion; It can be configured as follows.

In the above configuration, the module may include a support member that surrounds the first member and the second member and connects the third member and the second pressing portion.

In the above configuration, the module includes a plate-like member provided on a side opposite to the first member with respect to the third member and away from the third member, a central portion of the plate-like member, and the third member. and a shaft core member connecting the central portion of the.

The present invention has a bag-shaped first member having first and second surfaces facing each other and filled with gas, and third and fourth surfaces facing each other, the third surface being A bag-shaped second member facing the second surface and filled with gas, a first pressing portion in contact with at least the central portion of the first surface, and a second pressing portion in contact with at least the central portion of the fourth surface. a plate-like member provided away from the first pressing portion on a side opposite to the first member with respect to the first pressing portion; a center portion of the plate-like member and a center of the first pressing portion; and a shaft core member having a plane area smaller than that of the plate-like member, and detecting a difference between gas pressure in the first member and gas pressure in the second member. and a detector.

The present invention has a bag-shaped first member having first and second surfaces facing each other and filled with gas, and third and fourth surfaces facing each other, the third surface being A bag-shaped second member facing the second surface and filled with gas, a first pressing portion in contact with at least the central portion of the first surface, and a second pressing portion in contact with at least the central portion of the fourth surface. and a detector that detects a difference between the gas pressure in the first member and the gas pressure in the second member, wherein the first surface, the second surface, the second The third surface and the fourth surface are biological information detection devices arranged in a direction substantially perpendicular to the vertical direction.

In the above configuration, the module may be configured to be installed inside the seat of the vehicle.

The present invention is a seating determination device comprising the biological information detection device described above and a determination unit that determines whether or not a passenger is seated in a vehicle seat provided with the module based on the output of the detector. is.

According to the present invention, detection accuracy can be improved.

FIG. 1 is a schematic diagram showing a module and a differential pressure sensor in Example 1. FIG. FIG. 2 is a block diagram showing the detection device in Example 1. FIG. FIG. 3 is a diagram showing an example in which the modules in Example 1 are arranged on a seat. FIG. 4(a) is a plan view of the pad in Example 1, FIG. 4(b) is a sectional view along AA of FIG. 4(a), and FIGS. It is a cross-sectional view of the part. FIG. 5 is a diagram showing changes in pressure with respect to the amount of vibration applied to the pad. 6(a) and 6(b) are sectional views of the module in Example 1. FIG. 7A to 7C are sectional views of the module in Example 1. FIG. FIGS. 8(a) and 8(b) are diagrams showing another example of the first embodiment. FIGS. 9A and 9B are diagrams showing another example of the first embodiment. FIG. 10 is a cross-sectional view of a module according to Example 2. FIG. 11(a) to 11(d) are plan views of a module according to Example 2. FIG. 12 is a diagram showing the output signal of the detector against time in experiment 1. FIG. 13(a) and 13(b) are cross-sectional views of modules in

Modifications

1 and 2 of Example 2, respectively. 14 is a cross-sectional view of a module in Modification 3 of Embodiment 2. FIG. 15 is a cross-sectional view of a module according to Example 3. FIG. 16(a) to 16(d) are plan views of a module according to Example 3. FIG. 17 is a diagram showing the output signal of the detector against time in experiment 2. FIG. 18A is a cross-sectional view of a module according to Example 4, and FIGS. 18B and 18C are plan views of the module according to Example 4. FIG. FIG. 19(a) is a diagram showing the output signal of the sensor 20a with respect to time in Experiment 3, and FIG. 19(b) is a diagram showing a spectrum obtained by Fourier transforming the output signal in period 72 of FIG. 19(a). . 20 is a cross-sectional view of a module in Modification 1 of Embodiment 4. FIG. 21(a) is a cross-sectional view of the module in Comparative Example 5, and FIG. 21(b) is a cross-sectional view of the module in Example 5. FIG. 22(a) and 22(b) are cross-sectional views of a car seat in which modules are installed in Example 5. FIG. 23(a) to 23(d) are diagrams showing the output signal of the differential pressure sensor with respect to time in Experiment 4. FIG. 24(a) to 24(g) are diagrams showing the results of spectral analysis of FIG. 23(a) in Experiment 4. FIG. 25(a) to 25(g) are diagrams showing the results of spectrum analysis of FIG. 23(b) in experiment 4. FIG. 26(a) to 26(g) are diagrams showing the results of spectrum analysis of FIG. 23(c) in experiment 4. FIG. 27(a) to 27(g) are diagrams showing the results of spectrum analysis of FIG. 23(d) in Experiment 4. FIG. 28(a) and 28(b) are flowcharts showing the processing of the processing unit in the sixth embodiment. FIG. 29 is a flow chart showing a detection method according to the sixth embodiment.

Examples will be described below with reference to the drawings.

[Explanation of two stacked pads and a differential pressure sensor]
Example 1 is an example of a biological information detection device. FIG. 1 is a schematic diagram showing a module and a differential pressure sensor in a biological information detecting device according to Example 1. FIG. As shown in FIG. 1, module 10 includes pad 12 (first member) and pad 14 (second member). Pad 12 overlaps pad 14 .

Pads

12 and 14 may be in contact or may be spaced apart and not in contact.

Pads

12 and 14 are bag-like

members having spaces

11 and 13 filled with gas such as air. The

pads

12 and 14 are bags made of resin material, and the pressure in the

spaces

11 and 13 is kept at a level not to be crushed by the weight of the human body. The material of the

pads

12 and 14 may be a flexible material or a somewhat hard material as long as the material changes the pressure in the

spaces

11 and 13 by vibration. The material of the

pads

12 and 14 is, for example, resin such as polyethylene or polycarbonate. The outer shape of the

pads

12 and 14 is a thin rectangular parallelepiped, for example, a shape like a small air mat or cushion, or a shape like an edible pie dough that is circular or oval in plan view. 12 and 14 have a bag-like shape with a hollow structure. As described above, the

spaces

11 and 13 within the

pads

12 and 14 may be filled with other gas or liquid than air. It should be noted that the vibrations described above are, in other words, pressure fluctuations, and the forces are applied to

pads

12 and 14 . Then, the target biological information (vital vibration) is detected by the differential pressure sensor described below.

The differential pressure sensor 20 includes a housing 22, a vibrating membrane 24 and a sensor element 25. A strain is generated in the vibrating membrane 24 due to the force applied to the vibrating membrane 24 . The sensor element 25 is an element that converts the strain of the vibrating membrane 24 into an electrical signal. Here, the differential pressure sensor 20 in which the piezoelectric element is mounted on the vibrating membrane 24 as the sensor element 25 is shown. The differential pressure sensor 20 may be a differential pressure sensor that detects pressure. The sensor element 25 may be a capacitive sensor, an electret condenser microphone, a piezoresistive sensor, a differential transformer, or the like.

The housing 22 is a rigid body, and

spaces

21 and 23 are provided in the housing 22 with the diaphragm 24 as a boundary. The differential pressure sensor 20 may be a commercially available differential pressure sensor having a sensor element 25 other than a piezoelectric element and a built-in vibrating membrane 24 . In this case, the sensor element 25 is provided with a case (or housing) that protects the sensor body. Instead of the vibrating membrane 24, the size of the opening surrounded by the projecting portion 22a may be the size of the case of the sensor element 25, and the case of the sensor element 25 may be tightly inserted (fitted) into the opening. Thus, the

spaces

21 and 23 may be provided by the sensor element 25 and the protruding portion 22a. The shape and size of the

spaces

21 and 23 are preferably almost the same, for example. The shape of the housing 22 is, for example, a cylinder or a box, and the housing 22 is mainly made of metal or resin. The housing 22 in FIG. 1 is, for example, a cylinder having a circular top surface, a circular bottom surface, and side surfaces connecting the two.

[Regarding vital vibration and disturbance vibration]
In general, there are vibrations to be detected, and disturbance vibrations (hereinafter also referred to as noise) entering from the surroundings may make it difficult to detect the vibrations. In this environment, the first embodiment can detect desired vibrations with a simple configuration. In the embodiment of this specification, the vibration to be detected is, for example, the vital vibration of a passenger in a car, such as the vibration of breathing or pulse. On the other hand, disturbance vibration is vibration that enters as noise when vital vibration is detected. In the case of cars, the disturbance vibrations are drive noise or road noise. Drive noise includes, for example, road noise, drive sound, wind from an air conditioner, mechanical sounds such as engine sounds (motor sounds in EVs), body motion sounds of the human body, and the like. Road noise is the noise of an engine or motor driven vehicle running on the road, generally noise from the road and tires. Body motion noise is noise generated by the motion of the driver. In the following description, it is assumed that the vehicle is driven by the engine.

In addition, in the embodiment of the present specification, as an example, the detection of vital vibration while the vehicle is running will be described. However, there are various cases where detection of vital vibrations of the human body is required. For example, vital vibrations from a person sitting in a wheelchair, bed or cot, vital vibrations from a person running or walking, and the like. When an object picked up by a person or a person moves, it becomes difficult to detect the vital vibration of the human body because noise is superimposed on the vibration to be detected, as is the case with a person riding in a vehicle.

In addition, the purpose of the embodiments of the present specification is to efficiently detect the vibration to be detected in an environment where the vibration to be detected and the external disturbance vibration to be eliminated exist. For example, in a noisy factory, various cases are conceivable, such as detecting the vital vibration of a person, or detecting the good sound of an engine or a motor for processing.

[Quiet Case and Noise Case]
For example, when a car travels, it can be divided into cases where large noise such as road noise occurs and cases where no road noise occurs. The former is called an N (Noise) case as a case in which external vibration such as road noise occurs, and the latter is called an S (Silent) case because it is a quiet atmosphere.

The S case and N case are classified as follows from the viewpoint of extracting the vital signs of the vehicle occupants.
Case 1: The car engine is off and the passenger is sitting in the seat.
Case 2: The passenger is sitting on the seat and the car engine is running, but the car is stopped without running.
Case 3: A passenger is seated, the car engine is running, and the car is traveling at low speed on the road. Especially when driving on flat asphalt.
Case 4: The passenger is sitting in the seat, the vehicle engine is running, and the vehicle is traveling on a road, but the vehicle is traveling at high speed, on a gravel road, or on a rough road.

The explanations and experiments described below are roughly divided into two. That is, when large noise such as road noise and disturbance vibration are added, these are

Cases

3 and 4, which are called N Cases. Cases 1 to 3 when there is little noise are called S cases. Here, case 3 may correspond to the S case or the N case depending on the magnitude of the noise.

[Chassis]
Here, the housing is divided into two types. The first is a housing 52 (see FIG. 7(c)) in which the

pads

12 and 14 are placed. The second is a housing 22 that contains a sensor element 25 that detects pressure and vibration within the

pads

12 and 14 .

As described above, the housing 22 containing the sensor element 25 is a rigid body. A rigid body is a virtual object that does not change volume and shape, and is made of, for example, rigid plastic or metal. By using a rigid body for the housing 22, noise from the outside of the housing 22 is not taken into the housing 22 as much as possible. The housing 22 is a box made of a rigid body and surrounded by a strong plate. A rigid body will be described as a body that can exclude a bending component when external vibration is applied. This point will be described later. On the other hand, the housing 52 in which the pads are housed is divided into two parts, and when vibration is transmitted from the upper plate, the lower plate or the side plates, it is more flexible than the rigid body.

[Sensor element for differential pressure sensor]
The sensor element 25 has advantages and disadvantages depending on its type. A piezoelectric sensor has high resolution and high detection accuracy. However, since it is mounted on a part that vibrates, there is a possibility that the connection may become defective due to long-term use. On the other hand, the capacitive sensor has a structure in which capacitance is generated by two opposing electrodes. For example, at least one electrode vibrates to change the capacitance. Since no element is placed on the diaphragm or diaphragm, the possibility of poor connection due to sticking or the like is low. Thus, it is possible to use various sensor elements 25 for the differential pressure sensor 20, although there are advantages and disadvantages depending on the type of the sensor element 25. Therefore, the setting environment is taken into consideration when selecting the mode of use. In the following description, piezoelectric elements are mainly used.

[Differential pressure sensor]
A vibration film 24 is provided so as to partition the

spaces

21 and 23 . That is, the lower surface of the inner wall defining the space 21 is the upper surface of the vibrating membrane 24 , and the upper surface of the inner wall defining the space 23 is the lower surface of the vibrating membrane 24 . An inner wall corresponding to the side wall of the housing 22 is provided with a ring-shaped protruding portion 22a having a predetermined width over the entire circumference and protruding inward. A peripheral edge of the vibrating membrane 24 is bonded to the upper surface of the projecting portion 22a. The entire peripheral edge of vibrating membrane 24 is fixed to projecting portion 22a. Note that the vibrating membrane 24 may be provided on the lower surface of the projecting portion 22a. A side wall of the housing 22 is provided with connection pipes corresponding to the

spaces

21 and 23 . The pipes are referred to herein as

connections

28 and 29. FIG. The

connections

28 and 29 are provided for connecting the

tubes

26 and 27 . Therefore, the space 21 is connected (that is, communicated) with the space 11 inside the pad 12 via the connecting portion 28 and the tube 26 (first tube). The space 23 is connected to the space 13 inside the pad 14 via the connecting portion 29 and the tube 27 (second tube).

Spaces

21 and 23 are filled with air.

Spaces

21 and 23 may be filled with fluid such as gas or liquid other than air. A sensor element 25 is provided on the upper surface of the vibration film 24 . The vibrating membrane 24 temporarily receives vibrations (for example, pressure vibrations) from the

pads

12 and 14 and transmits them to the sensor element 25, so the sensor element 25 is provided so as not to overlap the projecting portion 22a.

When vibration is applied to the

pads

12 and 14, pressure is applied to the

pads

12 and 14 as described above, and the

pads

12 and 14 are deformed. As a result, the pressure of the gas in

spaces

11 and 13 changes. Changes in gas pressure are transmitted to

spaces

21 and 23 . When the vibrations applied to

pads

12 and 14 have the same phase and amplitude, vibrating membrane 24 hardly vibrates. Vibration corresponding to the difference between the vibrations applied to the

pads

12 and 14 is transmitted to the vibrating membrane 24 . The sensor element 25 detects the vibration (for example, pressure vibration) of the vibrating film 24 and outputs a detection signal to the signal processing device 30 (for example, a circuit). Thus, the differential pressure sensor 20 detects the difference between the gas pressure in the pad 12 (that is, the pressure of the gas filled in the space 11) and the gas pressure in the pad 14 (that is, the pressure of the gas that is filled in the space 13). to detect

[Sensor unit]
FIG. 2 is a block diagram showing the biometric information detection device according to the first embodiment. As shown in FIG. 2, the detection device 100 includes a module 10 and a sensor unit 31. As shown in FIG. The differential pressure sensor 20 outputs a detection signal to the circuit component 35 . The circuit component 35 includes, for example, a preamplifier (analog amplifier) and amplifies the detection signal. A printed circuit board may be provided inside the housing 22 of the differential pressure sensor 20 , and the circuit component 35 may be provided on this printed circuit board, or may be provided outside the housing 22 . Further, the preamplifier is prepared as one chip or one package, and if the preamplifier is equal to or smaller than the sensor element 25, the preamplifier may be provided on the front surface or the rear surface of the vibrating membrane 24.

When a preamplifier with a desired power supply voltage (for example, 3.3 V) converts and amplifies the output of the sensor element 25, saturation of the output signal does not occur as long as the amplified signal is within the power supply voltage range. . With large vibrations such as disturbance vibrations, the output of the sensor element 25 is large, and the output signal of the preamplifier is saturated. As a result, it may not be possible to detect small vibrations such as vital vibrations. The embodiments herein suppress the saturation of this output signal by suppressing the vibrations propagating to the

pads

12 and 14 in various ways, thereby detecting the desired vibrations. As described in the specification, even if the sensor element 25 is an element other than a piezoelectric element, saturation can be suppressed in a similar manner.

A signal processed by the circuit component 35 is output to the signal processing device 30 . The signal processing device 30 includes an amplifier 32, a processing section 34, a memory 36, an output section 38, and the like. Amplifier 32 amplifies the output signal of circuit component 35 . The gain of amplifier 32 is variable. The processing unit 34 is a processor such as, for example, a CPU (Central Processing Unit), AD (Analog Digital) converts the amplified signal, digitally processes the converted digital signal, and obtains vital information such as respiration and pulse wave. Perform the operation (or calculation) to extract. The memory 36 is a volatile memory or a non-volatile memory, and stores programs executed by the processing unit 34 and data being processed. The output unit 38 outputs the vital information calculated by the processing unit 34 to an external device. Wireless communication or wired communication, for example, is used to output vital information.

[Car seat]
FIG. 3 is a diagram showing an example in which the module 10 in Example 1 is arranged in a car seat. When the passenger sits on the car seat 41, the right direction is the +X direction side, the forward direction is the +Y direction side, and the upward direction is the +Z direction side. As shown in FIG. 3, a pedestal 42, a seat cushion 44 and a seat back 46 are provided as a car seat 41 in a four-wheeled vehicle. The pedestal 42 is, for example, a metal member. The seat cushion 44 is in contact with the thighs and buttocks of a passenger such as a driver, and the seat back 46 is in contact with the neck, back and hips of the passenger. A module 10 shown in FIG. 1 is provided in the seat cushion 44 . The seat cushion 44 is covered with a seat cloth (not shown). The seat cushion 44 is made of a soft resin, such as foamed resin such as urethane. When the passenger sits on the car seat 41, the right buttock of the passenger is positioned so as to overlap the module 10 in FIG. Vibrations such as the passenger's vital signs are transmitted to the module 10 via the right buttock and the seat cushion 44 . The module 10 may be placed over the left buttock or over the thigh. Alternatively, the module 10 may be placed in the seat back 46 to overlap the neck, back, or lumbar area.

The module 10 may be provided on a bicycle saddle, desk chair, bed, mat, bracelet, and the like. Here, a car seat 41 used in a four-wheeled vehicle is described as an example, but the car seat 41 shown in FIG. is also possible. These vehicles may be engine driven, motor driven, or the like. Also, the seat may be a home sofa or a chair with only a cushion without a seat back.

Also, the module 10 described below is to be embedded in a chair. As the module 10, as shown in FIGS. 7(a) to 7(c), a module without a shaft core member and a plate member, and as shown in FIGS. 8(a) and 8(b), a shaft core member and a module provided with a plate-like member, any module 10 is embedded in a sheet or the like as shown in FIG.

In the N case, where external vibration such as drive noise enters, and the silent S case, this module 10 was used to detect the pressure difference between the

pads

12 and 14 with the differential pressure sensor 20, and to extract vital vibration.

[Pushing part: the central part and peripheral part of the pad that the pushing part pushes]
First, the

pads

12 and 14 and the

pressing portions

16 and 18 that press the

pads

12 and 14 were considered. In the description of the first embodiment,

pads

12 and 14 correspond to the first member and the second member, respectively, except for the description of FIGS. 9(a) and 9(b). The upper surface 12a and the lower surface 12b of the pad 12 respectively correspond to the first and second surfaces facing each other. Upper surface 14a and lower surface 14b of pad 14 correspond to third and fourth surfaces facing each other, respectively.

Pushers

16 and 18 correspond to the first pusher and the second pusher, respectively.

4(a) is a plan view of the pad in Example 1, and FIG. 4(b) is a cross-sectional view taken along line AA of FIG. 4(a). 4(b) to 4(d) explain how to press the

pads

12 and 14. FIG. Actually, the pressing portion 16 of the pad 12 in FIG. 4(c) is in contact with the upper surface 12a of the pad 12, and the pressing portion 18 of the pad 14 in FIG. 4(d) is in contact with the lower surface 14b of the pad 14. . Both are illustrated in FIG. 4(b), so that both upper surface 12a and lower surface 14b are shown above

pads

12 and 14, and both lower surface 12b and upper surface 14a are shown below

pads

12 and 14. It is

First, in order to describe the positional relationship between the

pressing portions

16 and 18, the central portion 63 and the peripheral portion 64 will be described. As shown in FIGS. 4(a) and 4(b), the pad 12 has a central portion 63 and a peripheral portion 64 outside the central portion 63 . Since the upper surface 12a of the pad 12 or the lower surface 14b of the pad 14 is pushed by the

pressing portions

16 and 18, the central portion 63 and the peripheral portion 64 are used to define the positions of the upper surface 12a and the lower surface 14b with which the

pressing portions

16 and 18 abut. ing.

The central portion 63 is a region including the center 65 of the upper surface 12a and the lower surface 14b. Note that the center 65 is, for example, the center point (for example, the center of gravity) of the planar shape of the upper surface 12a and the lower surface 14b. As will be described later, the position where the pressing portion 16 abuts on the upper surface 12a is preferably the center 65 of the upper surface 12a of the pad 12, but deviation from the center 65 does not mean that vibration cannot be detected. In this sense, the central portion 63 in this specification is a portion having a width within which vibration can be detected. The peripheral edge portion 64 of the upper surface 12a or the lower surface 12b is roughly in the range of 20% or 30% of the planar area of the upper surface 12a or the lower surface 14b. As shown in FIG. 4(a), the central portion 63 may be a region away from the peripheral edge portion 64, or the central portion may be entirely inside the peripheral edge portion 64 as in a region 63a.

[Dot press and area press]
Two pressing methods, point pressing and surface pressing, will be described with reference to FIG. 4(b). In addition, the area where the

pressing portion

16 or 18 contacts the upper surface 12a or the lower surface 14b is called a contact area. The first pressing method is to press a range including the center 65 of the upper surface 12a or the lower surface 14b of the

pad

12 or 14 with a small contact surface, as indicated by an arrow 80a. This pressing method may be referred to as "point pressing" in this specification. Geometrically, a point has no area. Say.

The second way of pushing is to push the upper surface 12a or the lower surface 14b in a wide range including the center 65 from the left arrow 80b to the right arrow 80b in FIG. 4(b). For example, when the upper surface 12a or the lower surface 14b is pressed in almost the entire area from the left arrow 80b to the right arrow 80b, when the peripheral edge 64 of the upper surface 12a or the lower surface 14b is pressed in a ring shape, or when the upper surface 12a or the lower surface 14b is pressed. is rectangular in plan view, and the four corners of the peripheral portion 64 are pressed. This pressing method may be referred to as "surface pressing" in this specification. Also, as shown in FIG. 4(d), the pressing portion 18 presses the lower surface 14b with a contact area larger than that of the pressing portion 16, which is point pressing. In some cases, the

pressing portion

16 or 18 presses an area that is more than half of the planar area of . This case may also be referred to as "face pressing".

Returning to FIG. 4(b), when the central portion 63 of the upper surface 12a or the lower surface 14b is pushed as indicated by the arrow 80a, the

pads

12 and 14 have high leaf spring properties. Vibration can be detected even if the point to be pushed is slightly deviated from the center 65 . Therefore, as shown in FIG. 4(c), even if a small force such as a vital vibration is applied to the pressing portion 16 having a point pressing structure, the change in the pressure of the

pad

12 or 14 can be increased. In addition, if the portion of the upper surface 12a or the lower surface 14b that is pressed by the

pressing portion

16 or 18 is within the range of the central portion 63 described above, the effect is slightly different, but the vital vibration can be detected relatively large, and detection is possible. be.

On the other hand, I will explain the surface pressing structure. This is the case where the peripheral edge portion 64 of the upper surface 12a or the lower surface 14b is pushed as indicated by left and right arrows 80b in FIG. 4(b) (see FIGS. 10 to 11(d)). The leaf springiness of the

pad

12 or 14 decreases from the central portion 63 of the

pad

12 or 14 toward the peripheral edge portion 64 . That is, in surface pressing, vertical vibration of the upper surface 12a of the pad 12 or the lower surface 14b of the pad 14 is less likely than in point pressing. In other words, it can be considered that the surface pressing structure slightly suppresses the vibration of the

pad

12 or 14 and weakens the penetration of the vibration into the

pad

12 or 14 . For example, in the case of N case, the pressure difference between the

pads

12 and 14 due to disturbance vibration is reduced by the differential pressure sensor 20, and vital vibration is efficiently detected. As shown in FIG. 4(b), one pad (e.g. pad 12 in FIG. 4(c)) is made highly responsive and the other pad (e.g. pad 14 in FIG. 4(d)) is made less responsive. , it is important to provide a difference in the responsiveness of the two pads.

In the S case, when a small amount of vibration such as only vital vibration is applied and no large external vibration is applied, as shown in FIG. to detect vital vibrations. As shown in FIG. 4(d), another pad 14 suppresses the vibration of the pad 14 as surface pressing. As a result, the pressure difference between the two

pads

12 and 14 is increased.

On the other hand, like the N case, when a large amount of vibration such as disturbance vibration enters, the responsiveness of the two

pads

12 and 14 can be almost the same. In other words, in the surface-pressing structure of the pad 14, a large vibration is transmitted from below, and the vibration of the pressure inside the pad 14 is small. In the point pressing structure of the pad 12, the transmitted vibration is smaller than that of the pad 14, and the vibration of the pressure inside the pad 12 is small. Therefore, the pressure difference between

pads

12 and 14 is reduced. Although the magnitude of the pressure vibration of the

pads

12 and 14 is not exactly the same, if the pressure difference is detected, the output signal from the differential pressure sensor 20 due to the disturbance vibration becomes smaller. As a result, the output signal is not a signal that saturates the preamplifier. Details will be described later.

FIGS. 4(c) and 4(d) are cross-sectional views of the pad and the pressing portion. FIG. 5 is a diagram showing changes in pressure with respect to the amount of vibration applied to the pad. The amount of vibration corresponds to the force applied to

pads

12 and 14 and is indicated by the size of the arrow. As shown in FIGS. 4(c) and 4(d), the

pushers

18 and 16 are of two types. In FIG. 4C, the contact area between the pressing portion 16 and the upper surface 12a is smaller than the contact area between the pressing portion 18 and the lower surface 14b. In FIG. 4D, the pressing portion 18 abuts on the lower surface 14b over a wide area up to the peripheral edge portion 64 of the lower surface 14b.

In FIG. 5, a range 61 with a small amount of vibration corresponds to the S case. A range 62 where the amount of vibration is large corresponds to the N case. As shown in FIG. 4C, when the narrow pressing portion 16 presses the upper surface 12a of the pad 12 (arrow 80), the pressing portion 16 mainly presses the central portion of the upper surface 12a. A dotted line 75c in FIG. 5 indicates the change in the pressure in the space 11 with respect to the amount of vibration of the pressing portion 16 pressing the upper surface 12a of the pad 12. As shown in FIG. Since the central portion 63 has a high leaf spring property, the change in pressure with respect to the amount of vibration is large. As the amount of vibration that the pressing portion 16 presses against the upper surface 12a increases, the change in pressure also increases. In other words, if a small vibration is received by the point pressing structure, the change in the pressure inside the pad 12 can be increased. Also, even if the location where the pressing portion 16 presses the upper surface 12a deviates from the center 65 to some extent, the vibration can be detected within the range where the location where the pressing portion 16 presses the upper surface 12a is the central portion.

As shown in FIG. 4(d), when the wide pressing portion 18 presses the lower surface 14b of the pad 14 (arrow 81), the pressing portion 18 presses the area from the central portion 63 to the peripheral portion 64 of the lower surface 14b. do. The contact area of the pressing portion 18 only has to be larger than the contact area of the pressing portion 16 , and the pressing portion 18 does not have to press up to the peripheral edge portion 64 . For example, the contact area of the pressing portion 18 can be selected within a range from half or more of the area of the lower surface 14b to the area of the entire area of the lower surface 14b. When the pressing portion 18 presses the entire region from the central portion 63 to the peripheral edge portion 64 of the lower surface 12b, as described above, if the pressing portion 18 presses a wide range of the lower surface 12b, the springiness as a whole decreases. Therefore, as indicated by the solid line 75b in FIG. 5, the change in pressure with respect to the amount of vibration is small. That is, the surface pressing structure lowers the responsiveness of the pad 14 . That is, large vibrations such as disturbance vibrations are reduced and taken into the pressure inside the pad 14 . In the embodiment of the present specification, by selectively using the point pressing structure and the surface pressing structure, large disturbance vibration such as road noise is canceled by the pressure difference between the

pads

12 and 14 . This point will be explained below.

[Pressing part that changes from point pressing to surface pressing]
6(a) and 6(b) are sectional views of the module in Example 1. FIG.

[Convex pressing part and flexible pad]
As shown in FIGS. 6A and 6B, the pressing portion 16 has a three-dimensional shape in which the cross-sectional area parallel to the upper surface 12a decreases toward the bottom. The pressing portion 16 includes, for example, a structure like a sliced ball, and the lower surface 14b has a convex shape with an inclined surface or a curved surface. As for the pressing portion 16 in FIGS. 8A and 8B, the contact area of the pressing portion 16 gradually increases as the force increases. This is a mechanism in which the pressing portion 16 enters the pad 12 due to the flexibility of the pad 12, as shown in FIGS. 6(a) and 6(b). However, the pressing portion 16 side may be made flexible, and the pressing portion 16 itself may be deformed into surface contact. For example, the pressing part 16 may be a bag-shaped member such as a balloon, placed on a flat surface, and pressed from above.

10, 13(a), 13(b) and 14 digitally changes the contact area of the pressing portion 16 from a small area to a large area at a certain force as the force increases. change to This is also a structure that changes from point pressing to surface pressing. On the other hand, the pressing portion 18 has a wide contact surface and a columnar shape. The contact area of the pressing portion 18 is large and corresponds to a surface pressing structure.

As shown in FIG. 6(a), when the amount of vibration that presses the upper surface 12a and the lower surface 14b is small, for example, in the case of the S case, the driver's buttocks are positioned upward, so that the pressing portion 16 is positioned at the central portion 63 of the upper surface 12a. mainly. Therefore, as indicated by the dashed line 75a in FIG. 5, in the range 61 where the amount of vibration is small, the center 65 vibrates more easily, so the change in pressure in the space 11 increases. On the other hand, since the pressing portion 18 has a surface-pressing structure, vital vibrations and other noises are less likely to be transmitted to the pad 14 . Therefore, vital vibration can be detected by detecting the pressure difference with the differential pressure sensor 20 .

When the amount of vibration that presses the upper surface 12a and the lower surface 14b is large, for example, in the case of N case, as shown in FIG. push. As a result, the pressing portion 16 changes analogously (continuously) from the point pressing structure to the surface pressing structure. Therefore, as indicated by the dashed line 75a in FIG. 5, in the range 62 where the amount of vibration is large, both the

pads

12 and 14 have a surface pressing structure, and the vibration is less likely to be transmitted to the

pads

12 and 14. FIG. Therefore, pressure changes in the

spaces

11 and 13 within the

pads

12 and 14 are suppressed. This causes the pressure changes in

spaces

11 and 13 to be similar or close to each other. In other words, if the vibration is disturbance vibration, the two

pads

12 and 14 are subjected to disturbance vibration of the same degree, and the disturbance vibration can be canceled by taking the difference. Even if it cannot be canceled completely, it can be canceled to some extent, so that the output signal of the differential pressure sensor 20 due to the disturbance vibration can be reduced. That is, saturation of the preamplifier due to disturbance vibration can be suppressed, and vital vibration superimposed on disturbance vibration can be detected.

Thus, the pressing portion 16 is positioned at the central portion 63 of the upper surface 12a when viewed from the stacking direction (Z direction) of the

pads

12 and 14. As shown in FIG. When the force applied in the −Z direction (the direction toward the upper surface 12a) is small, the area of the pressing portion 16 in contact with the upper surface 12a is small as shown in FIG. 6(a). As the force increases, the contact area of the pressing portion 16 with the upper surface 12a increases as shown in FIG. 6(b). After that, when the force becomes smaller, it returns to FIG. 6A, and the area of the pressing portion 16 in contact with the upper surface 12a becomes smaller. On the other hand, the pressing portion 18 has a surface pressing structure and contacts at least the central portion of the lower surface 14b of the pad 14, and even if the magnitude of the force changes, the contact area between the pressing portion 18 and the lower surface 14b hardly changes. That is, the distance between the upper surface 12a of the pad 12 and the lower surface (fifth surface) of the pressing portion 16 decreases from the peripheral portion toward the central portion. Vibration can be transmitted between the upper surface 12 a and the lower surface of the pressing portion 16 .

The central portion of the surface 16d of the pressing portion 16 facing the upper surface 12a of the pad 12 protrudes toward the pad 12 from the peripheral edge portion 64. As shown in FIG. Therefore, when no force is applied from the pressing portion 16 to the upper surface 12a or when the force is small (in the point pressing structure), the area of the pressing portion 16 in contact with the upper surface 12a is preferably 1/4 or less of the planar area of the pad 12. 1/16 or less is more preferable.

[Separator: Prevention of mutual interference between pads 12 and 14]
Next, the separator will be explained. 7A to 7C are sectional views of the module in Example 1. FIG. A case where the width of the upper pressing portion 16 is narrow and the width of the lower pressing portion 18 is large will be described. The pressing portion 16 has a small contact area and has a point pressing structure, and the pressing portion 18 has a large contact area and has a surface pressing structure. In FIG. 7A, the lower surface 12b of the pad 12 and the upper surface 14a of the pad 14 are in contact. When two

pads

12 and 14 are in contact, the vibrations of

pads

12 and 14 interfere with each other, arrow 82 . With this structure, the detection accuracy is slightly lower than that of FIG. 7B, but it is possible to detect vital vibrations.

On the other hand, FIG. 7(b) shows a state in which the two

pads

12 and 14 are separated by the separator 50. FIG. The separator 50 is positioned between the lower surface 12b of the pad 12 and the upper surface 14a of the pad 14 and provided on the peripheral edge thereof. Moreover, the separator 50 is provided in contact with the lower surface 12b and the upper surface 14a. Since the peripheral portions of the

pads

12 and 14 have a low leaf spring property, the vibrations are less likely to be transmitted to the

pads

12 and 14 through the separator 50 . Moreover, it can be said that the

pads

12 and 14 are pressed against each other, and the propagation of vibration between the

pads

12 and 14 is suppressed. Furthermore, the lower surface 12b of the pad 12 and the upper surface 14a of the pad 14 are not in contact with each other and are separated from each other. Thereby, the interference of the vibrations of the

pads

12 and 14 can be further suppressed. Therefore, compared with the structure of FIG. 7A, the detection accuracy of vital signals is improved. The separators 50 may be provided in a ring shape on the peripheral edges of the lower surface 12b and the upper surface 14a, or may be independently provided at four corners of the lower surface 12b and the upper surface 14a. If the lower surface 12b and the upper surface 14a have different sizes, the separator 50 may be provided on the peripheral edge of at least one of the lower surface 12b and the upper surface 14a. This technical idea of the separator is applied to all the embodiments.

[Case: Prevention of destruction of built-in parts and prevention of noise intrusion from the side]
As shown in FIG. 7(c), the housing 52 surrounds the

pads

12 and 14 with inner walls. The housing 52 has an upper plate 52a, a lower plate 52b and side plates 52c. The planar shape of the

pads

12 and 14 also changes the shape of the housing 52 . For example, if the planar shapes of the

pads

12 and 14 are circular, the housing 52 has a cylindrical shape, and if the planar shapes of the

pads

12 and 14 are polygonal, the housing 52 has a prismatic shape. The lower surface of the upper plate 52 a contacts the pressing portion 16 . The upper surface of the lower plate 52b contacts the pressing portion 18. As shown in FIG. The upper plate 52a and the lower plate 52b are flat plates.

The side plate 52c forms a box by connecting the periphery of the upper plate 52a and the periphery of the lower plate 52b. The housing 52 surrounds the

pads

12 and 14 and is provided away from the sides or perimeters of the

pads

12 and 14 . Between the side plate 52c and the

pads

12 and 14 is a gap 53 made of air or the like. The side plate 52c may be a ring-shaped plate surrounding the

pads

12 and 14, or may be connected by a plurality of plates extending in the Z direction. For example, if the housing 52 is a hexahedron, the side plates 52c are four plates. Also, the

tubes

26 and 27 shown in FIG. 1 are pulled out to the outside through holes provided in the side plate 52c. Although an example in which the inside of the housing 52 is filled with air has been described, the inside of the housing 52 may be filled with fluid, that is, gas or liquid other than air.

Thus, the housing 52 surrounds the

pads

12 and 14 and connects the

pressing portions

16 and 18. With this construction, the

pads

12, 14, etc. will not break even if the module 10 is subjected to excessive body weight. Further, since the periphery of the

pads

12 and 14 does not touch the inner wall, the vibration transmitted from the outside of the side plate 52c can be suppressed from entering the

pads

12 and 14 from the side plate 52c. It is considered that the side faces of the housing 52 are close to each other in a pressing structure, so that large noise vibrations from the outside are difficult to propagate. In the S case, the pressing portion 16 transmits vital vibrations to the pad 12 with a large vibration, and the vital vibrations are transmitted to the lower plate 52b via the side plate 52c. This vital vibration and other small noises enter the lower plate 52b. However, the pressing portion 18 is a surface pressing, which suppresses the propagation of vibration to the pad 14 . Therefore, a pressure difference is generated between the

pads

12 and 14, and the differential pressure sensor 20 can detect vital vibration. In case N, disturbance vibration is transmitted to the upper plate 52a and the lower plate 52b. However, differential pressure sensor 20 detects the pressure difference between

pads

12 and 14 . Therefore, disturbance vibration is less likely to be detected by the differential pressure sensor 20, and vital vibration can be detected while suppressing saturation of the output signal by the preamplifier.

The housing 52 is made of a harder material than the

pads

12 and 14, and is mainly made of hard resin such as acrylic or metal. Except for the upper plate 52a, the lower plate 52b and the side plates 52c may be integrally molded. The top plate 52a may be a lid with a packing. The upper plate 52a, the lower plate 52b, and the side plate 52c may be separate members, and may be joined with a jointing agent or the like. The upper plate 52a and the pressing portion 16 may be integrally formed, or may be separate members that are joined by a bonding agent or the like. The lower plate 52b and the pressing portion 18 may be integrally formed, or may be separate members that are joined by a jointing agent or the like. The

pressing portions

16 and 18 may correspond to the first pressing portion and the second pressing portion, respectively, and the housing 52 may correspond to the support member. The pressing portion 16 and the upper plate 52a may correspond to the first pressing portion, the pressing portion 18 and the lower plate 52b may correspond to the second pressing portion, and the side plate 52c may correspond to the supporting member. Although the separator 50 and the housing 52 have been described here, the technical concept of the separator 50 or the housing 52 can be applied to all embodiments.

[Axis core member 54 and plate member 55]
FIGS. 8(a) to 9(b) are diagrams showing another example of the first embodiment. As shown in FIG. 8A, the plate-like member 55 is provided on the side of the top plate 52a opposite to the pad 12 and is spaced apart from the top plate 52a. The shaft core member 54 connects the central portion of the plate member 55 and the central portion of the upper plate 52a. The area obtained by cutting the axial core member 54 in the plane direction (hereinafter referred to as plane area) is smaller than the plane area of the plate member 55 . A load of the human body 60 is applied to the plate member 55 . A cushion material may be provided between the plate member 55 and the human body 60 . The shaft core member 54 transmits the vibration of the human body 60 to the central portion of the upper plate 52a. The sources of vital vibrations of the human body 60 are small areas. Even if the seating position of the human body 60 deviates in the X and Y directions, the vital vibration from the vital vibration source is transmitted from the plate-like member 55 to the upper plate 52a via the shaft core member . This is analogous to the principle of operation of a top plate scale. For example, even if the object to be measured deviates from the center of the upper plate, the weight does not change.

The axis, as the name suggests, means the axis located in the center, and here, it refers to the axis that is arranged approximately in the center of the plate-like member 55 that serves as the upper plate. Even if the position of the buttocks of the human body or the position of the blood vessel deviates from the center of the plate-like member 55, the vital vibration propagates through the plate-like member 55 and passes through the shaft core member 54 to the upper plate 52a, which is a diaphragm. Propagate to the central part. Therefore, even if the vital vibration source is slightly displaced from the center of the plate member 55 , the vital vibration is transmitted to the pad 12 .

　Since the central part of the upper plate 52a has a high leaf spring property, the vibration is transmitted from the pressing part 16 to the pad 12. In order to transmit vital signals to the pad 12 even if the seating position of the human body 60 is shifted, the planar area of the axial core member 54 is preferably 1/4 or less, more preferably 1/10 or less, of the planar shape of the plate member 55. . The plate-like member 55, the shaft core member 54 and the upper plate 52a may be integrally formed, or may be separate members joined by an adhesive or the like.

[Convex pressing part 16]
The upper surface 12a of the pad 12 is a flat surface, and the downward surface 16d of the pressing portion 16 facing the upper surface 12a of the pad 12 is curved so that the central portion protrudes below the peripheral portion. When the pad 12 is not subjected to vibration, the pressing portion 16 has a small contact area with the upper surface 12a. As the vibration increases, the pressing portion 16 enters the pad 12 and the area in contact with the upper surface 12a increases. After that, when the vibration becomes smaller, it returns to the original state, and the area of the pressing portion 16 in contact with the upper surface 12a becomes smaller.

In the case of the S case without external vibration, the vital vibration transmitted to the pressing portion 16 via the shaft core member 54 causes the pressing portion 16 to press the surface of the pad 12 with a point pressing structure. As a result, the central portion of the upper surface 12a of the pad 12 vibrates greatly in the vertical direction. On the other hand, since the pressing portion 18 of the lower plate 52b has a surface pressing structure, vibration propagation to the pad 14 is suppressed. Furthermore, since the differential pressure sensor 20 detects the pressure difference between the

pads

12 and 14, it can detect vital vibrations.

On the other hand, in the case of N case, large vibration such as disturbance vibration enters from the lower plate 52b. The side plate 52 c of the housing 52 deforms slightly outward, the upper plate 52 a pushes the pressing portion 16 , and the pressing portion 16 sinks into the pad 12 . As a result, the pressing portion 16 changes to a surface pressing structure. Since the disturbance vibration also wraps around the plate member 55, the pressing portion 16 is made flatter. Further, the pad 14 has a pressing portion 18 having a surface pressing structure from the beginning. Therefore, large forces such as disturbance vibrations are transmitted to

pads

12 and 14 . By detecting the pressure difference between the

pads

12 and 14 with the differential pressure sensor 20, the vibration transmitted to the

pads

12 and 14 can be canceled to some extent. Therefore, the output signal of the differential pressure sensor 20 becomes smaller due to the disturbance vibration. Saturation of the preamplifier can be suppressed. Therefore, it is possible to improve the detection accuracy of the vital vibration superimposed on the disturbance vibration.

As shown in FIG. 8(b), a separator 50 is provided on the peripheral portion between the

pads

12 and 14. As shown in FIG. By providing the separator 50, vibration interference between the

pads

12 and 14 can be suppressed, and detection accuracy can be improved. Other configurations are the same as those in FIG. 8A, and descriptions thereof are omitted. 8A and 8B, the pressing portion 16 may be in contact with the lower plate 52b, and the pressing portion 18 may be in contact with the upper plate 52a. In short, the configurations of the

pressing portions

16, 18, the

pads

12, 14, and the separator 50 may be upside down.

　In Figures 9(a) and 9(b), the

pads

14 and 12 correspond to the first member and the second member, respectively. The lower surface 14b and the upper surface 14a of the pad 14 respectively correspond to the first and second surfaces facing each other. Lower surface 12b and upper surface 12a of pad 12 correspond to third and fourth surfaces facing each other, respectively. The lower plate 52b corresponds to the first pressing portion. The pressing portion 16 and the upper plate 52a correspond to the second pressing portion.

[Curved pad 14]
As shown in FIG. 9(a), the pressing portion 16 is wide and provided from the central portion to the peripheral portion of the upper surface 12a of the pad 12. As shown in FIG. That is, the pressing portion 16 has a surface pressing structure. The central portion of the lower surface 14b of the pad 14 protrudes toward the lower plate 52b from the peripheral portion. That is, the pressing portion 18 has a point pressing structure. Thus, the inner surface of the lower plate 52b is flat, and the lower surface 14b of the pad 14 protrudes. With this structure, the pad 12 side has a surface pressing structure, and the pad 14 has a point pressing structure. 6(a) and 6(b), the pressing part 16 is changed from point pressing to surface pressing, but in FIG. Change from push to face push structure.

Therefore, in a situation such as the S case where external vibration is not applied, vital vibration is transmitted through the plate-like member 55, the shaft core member 54, the upper plate 52a, the pressing portion 16, and the peripheral edge (side wall) portion of the pad 12. 14 is transmitted. Since the lower plate 52b has a point pressing structure, even a small vibration such as a vital vibration is transmitted to the pad 14 side. (The separator is also mediated in FIG. 9(b))
Therefore, the lower pad 14 vibrates greatly, and the upper pad 12 is suppressed from vibrating. After all, detecting the pressure difference between the

pads

12 and 14 allows detection of vital vibrations.

On the other hand, in the case of the N case, when large vibration such as external vibration is applied, the lower plate 52b and the pad 14 have a surface pressing structure, and the upper plate 52a, the pressing portion 16 and the pad 12 have a surface pressing structure. As a result, propagation of disturbance vibration to

pads

12 and 14 is suppressed. Furthermore, when the pressure difference between the

pads

12 and 14 is detected by the differential pressure sensor 20, the output signal due to disturbance vibration is reduced, and the detection accuracy of vital vibration can be improved.

As shown in FIG. 9(b), a separator 50 is provided on the peripheral portion between the

pads

12 and 14 can be suppressed. The principle and effect of separator 50 are as described above. Other configurations are the same as those in FIG. 9A, and descriptions thereof are omitted. 9A, the upper surface 12a of the pad 12 protrudes toward the upper plate 52a, the lower surface 14b of the pad 14 is flat, and the pressing portion shown in FIG. 9A is provided between the pad 14 and the lower plate 52b. A pressing portion 18 having a structure similar to that of 16 may be provided, or a separator 50 may be provided as shown in FIG. 9(b). In short, the configurations of the

pressing portions

16, 18, the

pads

12, 14, and the separator 50 may be upside down.

The elastic modulus of the material used for the

pads

12 and 14 is preferably 2 MPa to 5000 MPa. For example, the material of

pads

12 and 14 is polyethylene resin (modulus of elasticity: 1080 MPa). The elastic modulus of the material used for the

pressing portions

16, 18, the separator 50, the housing 52, the shaft core member 54 and the plate-like member 56 is preferably larger than the elastic modulus of the material used for the

pads

12 and 14, for example 2 MPa. ~10000 MPa is preferred. The same applies to the following examples. For example, the material of the

pressing portions

16 and 18, the separator 50, the housing 52, the shaft core member 54 and the plate member 56 is acrylic resin (3000 MPa).

[Structure having

pressing portions

16a and 16b]
FIG. 10 is a cross-sectional view of a module according to Example 2. FIG. 11(a) to 11(d) are plan views of a module according to Example 2. FIG. FIG. 11(a) illustrates the plate member 55 and the shaft member 54. FIG. FIG. 11(b) illustrates the pad 12, the

pressing portions

16a and 16b, and the side plate 52c. FIG. 11(c) illustrates

pads

12, 14, separator 50 and side plate 52c. FIG. 11(d) illustrates the pad 14, the pressing portion 18 and the lower plate 52b. In Example 2,

pads

12 and 14 correspond to the first and second members, respectively. The upper surface 12a and the lower surface 12b of the pad 12 respectively correspond to the first and second surfaces facing each other. Upper surface 14a and lower surface 14b of pad 14 correspond to third and fourth surfaces facing each other, respectively. The upper plate 52a corresponds to the third member. The

pressing portions

16a and 16b correspond to the first pressing portion and the second pressing portion, respectively. The pressing portion 18 and the lower plate 52b correspond to the third pressing portion. The side plate 52c corresponds to the support member.

As shown in FIGS. 10 to 11(d), two

pressing portions

16a and 16b are provided between the upper plate 52a and the pad 12. As shown in FIGS. The pressing portion 16a is located in the central portion of the upper surface 12a of the pad 12. As shown in FIG. The pressing portion 16a is in contact with and fixed to the upper plate 52a. When no force is applied from the pressing portion 16a to the pad 12 or when the force is small (in case S), the pressing portion 16a and the upper surface 12a are not in contact with each other. When the force increases as in case N, the pressing portion 16a and the pressing portion 16b come into contact with the upper surface 12a at a certain point. When the force is reduced, the pressing portion 16a and the upper surface 12a are separated and returned to their original state. The pressing portion 16b is located between the upper surface 12a and the upper plate 52a, at the peripheral portion of the upper surface 12a, and is always in contact with the upper surface 12a and the upper plate 52a regardless of the magnitude of the force. The pressing portions 16 b are provided at the four corners of the pad 12 . As long as the pressing portion 16b is provided on the peripheral portion of the upper surface 12a, the pressing portion 16b may be ring-shaped, or may be provided on a pair of opposing sides of the upper surface 12a. The separators 50 are provided at four corners of the lower surface 12b of the pad 12 and the upper surface 12a of the pad 14. As shown in FIG. As long as the separator 50 is provided on the periphery of the lower surface 12b and the upper surface 14a, the separator 50 may be ring-shaped, or may be provided along two opposite sides of the upper surface 12a. Other configurations are the same as those in FIG.

The operation of the module of Example 2 will be explained. First, the S case, in which the module 10 is not subjected to external vibrations and the module 10 is subjected to vital vibrations from the human body 60, will be described. Considering the separator 50 as a fixed end, the vital vibration is transmitted to the plate-like member 55, the axial core member 54 and the upper plate 52a. The shaft core member 54 is in contact with the central portion of the upper plate 52a. The shaft core member 54 constitutes a point pressing structure, and the vital vibration is transmitted to the upper plate 52a. The pressing portion 16b is provided on the peripheral portion of the upper surface 12a of the pad 12. As shown in FIG. Therefore, the pressing portion 16b has a surface pressing structure. Therefore, the vibration of the pad 12 is suppressed, and the vibration transmitted from the upper plate 52 a to the pressing portion 16 b is less likely to be transmitted to the pad 12 . Since the pressing portion 16a is not in contact with the pad 12, the vital vibration is hardly transmitted to the pad 12 even through the pressing portion 16a. The vital vibration is transmitted from the upper plate 52a to the pad 14 via the side plate 52c, the lower plate 52b and the pressing portion 18. As shown in FIG. The contact area of the pressing portion 18 on the pad 14 side is smaller than the contact area of the pressing portion 16b on the pad 12 side, and the vital vibrations transmitted to the

pads

12 and 14 are different. Therefore, when the pressure difference between the

pads

12 and 14 is detected by the differential pressure sensor 20, the vital vibration can be detected, although the difference is slightly reduced.

Next, in the case of the N case, the case where external vibration such as external vibration is applied to the module 10 will be described. When this large vibration is applied to the plate-like member 55, the disturbance vibration transmitted from the plate-like member 55 causes the upper plate 52a to be deformed downwardly. Therefore, the two

pressing portions

16a and 16b are both in contact with the upper surface 12a. Note that the pressing portion 16b may be deformed flat. Therefore, the external vibration transmitted to the housing 52 causes the

pressing portions

16a and 16b and the pad 12 to change into a surface pressing structure. Furthermore, a large external vibration applied from below is transmitted from the pressing portion 16 a of the surface pressing structure to the pad 12 and from the pressing portion 18 to the pad 14 . By setting the sum of the contact areas of the

pressing portions

16a and 16b to be the same as the contact area of the pressing portion 18 to some extent, the pressure changes of the

pads

12 and 14 can be made approximately the same. As a result, the disturbance vibration is canceled by the differential pressure sensor 20 to some extent, and the output signal of the differential pressure sensor 20 can be reduced. Therefore, the saturation of the preamplifier is suppressed, and the vital vibration superimposed on the disturbance vibration can be detected. 10, a pressing portion 16 having the same shape as the pressing portion 18 in FIG. 10 is provided between the pad 12 and the upper plate 52a, and a pressing portion having the same shape as the pressing portion 16a in FIG. 10 is provided on the lower plate 52b. A pressing portion having the same shape as the pressing portion 16b shown in FIG. In short, the

pressing portions

16a, 16b, 18, the

pads

12, 14, and the separator 50 may be arranged upside down.

[Experiment 1]
Using the module of Example 2, changes in pressure in

spaces

11 and 13 due to vital vibration and disturbance vibration were detected. The material of

pads

12 and 14 is polyethylene. Other members were made by cutting an acrylic plate. An instant adhesive was applied to the cut members so as to have a thickness of 0.1 mm, and then the members were joined.

The dimensions of each member are as follows.
Plate member 55: X x Y x Z = 55 mm x 55 mm x 2 mm
Axial core member 54: X x Y x Z = 15 mm x 15 mm x 1 mm
Upper plate 52a: X×Y×Z=55 mm×55 mm×1 mm
Lower plate 52b: X×Y×Z=55 mm×55 mm×3 mm
Side plate 52c: X, Y=55 mm (width)×5 mm (thickness), Z=21.6 mm
Holes (X, Y×Z=8 mm×15 mm) for

Tubes

26 and 27 are Formed on One Surface of Side Plate 52c The upper plate 52a, the lower plate 52b and the side plate 52c are bonded using an adhesive having a thickness of 0.1 mm.
Pressing portion 16a: X×Y×Z=15 mm×15 mm×1 mm
Pushing portion 16b: X×Y×Z=5 mm×5 mm×2 mm
Pressing portion 18: X x Y x Z = 25 mm x 25 mm x 1 mm
Separator 50: X x Y x Z = 5 mm x 5 mm x 2 mm
Pads 12, 14: X x Y x Z = 40 mm x 40 mm x 8 mm, thickness is 1 mm

A urethane material used for the sheet was prepared, and it was made into a cushion shape of X x Y x Z = 300 mm x 300 mm x 60 mm, a counterbore was provided in the center of the cushion, and the created module 10 was installed in the counterbore. Using the same urethane material as the floor cushion, the countersunk was covered with a lid. A weak vibration corresponding to a vital signal was applied to the lid by lightly pressing the top surface of the lid with a finger. A strong vibration equivalent to the disturbance vibration was applied to the lid by striking the lid with a hand. The pressure in

spaces

11 and 13 of

pads

12 and 14 was detected by a detector.

FIG. 12 is a diagram showing the output signal of the detector against time in Experiment 1. In FIG. 12, a period 70 is a period in which the vibration corresponding to the vital signal is applied, and a period 71 is a period in which the vibration corresponding to the disturbance vibration is applied. As shown in FIG. 12, during period 70 the output signal from pad 14 is greater than the output signal from pad 12 . Therefore, even if the differential pressure sensor 20 is used to cancel pressure changes in the

pads

12 and 14, it is considered possible to detect vital vibrations. During period 71, the output signals from

pads

12 and 14 are approximately the same magnitude. Therefore, it is considered that the disturbance vibration can be canceled by using the differential pressure sensor 20 to cancel the pressure change of the

pads

12 and 14 . This point will be explained below.

According to the second embodiment, the pressing portion 16a is positioned between the upper surface 12a and the upper plate 52a (third member), and is positioned in the center of the upper surface 12a. When no force is applied from the upper plate 52a toward the pad 12 or the force is small, that is, in the S case, the pressing portion 16a does not come into contact with the pad 12. FIG. However, in the N case, the greater the force, the more it touches the pad 12 . The pressing portion 16b (third pressing portion) is positioned between the upper surface 12a and the upper plate 52a, is positioned on the peripheral edge of the upper surface 12a, and contacts the upper surface 12a and the upper plate 52a. Vibration can be transmitted between the upper surface 12a and the upper plate 52a via the pressing portion 16a. The pressing portion 18 contacts at least the central portion of the lower surface 14b. That is, the

pads

12 and 14 each have a surface pressing structure, and external vibration such as road noise is transmitted to the

pads

12 and 14 with the vibration reduced. As a result, the disturbance vibration is canceled in the differential pressure sensor 20 to some extent, the output signal of the differential pressure sensor 20 becomes small, and the vital vibration superimposed on the disturbance vibration can be detected.

[Modification 1 of Embodiment 2]
FIG. 13A is a cross-sectional view of a module in Modification 1 of Embodiment 2. FIG. As shown in FIG. 13(a), in the S case, when no force such as vital vibration is applied to the module or when the force is small, the pressing portion 16a is not in contact with the upper plate 52a. In case N, when the force increases, the upper plate 52a deforms and the pressing portion 16a comes into contact with the upper plate 52a. When the force is reduced again, the pressing portion 16a is separated from the upper plate 52a and returns.

In the S case, when a small vibration such as vital vibration is applied to the module, even if the vital vibration is transmitted to the upper plate 52a through the shaft core member 54, the center of the pad 12 is not in contact with the upper plate 52a. Vibration is hardly transmitted from the pressing portion 16b to the pad. The vibration is transmitted mainly to the pad 14 via the side plate 52c, the lower plate 52b and the pressing portion 18. As shown in FIG. Therefore, a pressure difference is generated between the

pads

12 and 14, and the differential pressure sensor 20 can detect vital vibration.

In case N, when a large external vibration such as road noise is applied to the module, the upper plate 52a is deformed and the pressing portion 16a comes into contact with the upper plate 52a. That is, the pressing portion 16a has a surface pressing structure. Since both the pad 14 and the pressing portion 18 have a surface-pressing structure, disturbance vibration is suppressed and transmitted to the

pads

12 and 14 . If the pressure difference between the

pads

12 and 14 is detected, the signal of disturbance vibration is canceled to some extent by the differential pressure sensor 20 . Therefore, the output signal of the differential pressure sensor 20 becomes small, and the output of the preamplifier becomes non-saturated. Therefore, the vital vibration superimposed on the disturbance vibration can be detected. Other configurations are the same as those of the second embodiment, and description thereof is omitted.

Subsequently, the pressing portion 16a may contact the upper plate 52a and be spaced apart from the pad 12 in a relationship opposite to that of the second embodiment and its first modification. A pressing portion 16 having the same shape as the pressing portion 18 in FIG. 13A is provided between the pad 12 and the upper plate 52a, and a pressing portion having the same shape as the pressing portion 16a in FIG. A pressing portion having the same shape as the pressing portion 16b may be in contact with the pad 14 and the lower plate 52b. In short, the

pressing portions

16a, 16b, 18, the

pads

12, 14, and the separator 50 may be arranged upside down.

[Modification 2 of Embodiment 2]
FIG. 13(b) is a cross-sectional view of a module in Modification 2 of Embodiment 2. FIG. As shown in FIG. 13(b), in the S case, when no force is applied from the upper plate 52a to the pad 12 or the force is small, the contact area of the pressing portion 16a with the upper surface 12a of the pad 12 is small, or It is spaced apart, and the pressing portion 16a has a point pressing structure. In case N, as the force increases, the area of contact between the pressing portion 16a and the upper surface 12a increases. The pressing portion 16a has a surface pressing structure. Further, when the force is reduced, the contact area of the pressing portion 16a with the upper surface 12a is reduced, and the original state is restored. In FIG. 13(b), the vital vibration is transmitted mainly to the pad 14 in the S case, and the disturbance vibration is transmitted to both the

pads

12 and 14 in the N case.

In case S, the vital vibration is transmitted to the plate-shaped member 55, the shaft core member 54 and the upper plate 52a. The shaft core member 54 is in contact with the central portion of the upper plate 52a, the shaft core member 54 constitutes a point pressing structure, and the vital vibration is transmitted to the upper plate 52a. The pressing portion 16b is in contact with the peripheral portion of the pad 12 and the housing 52, and the pressing portion 16a is not in contact with the pad 12 or is in weak contact therewith. Not much vital vibration is transmitted from the pressing portion 16b to the pad 12. - 特許庁The vital vibration is transmitted to the pad 14 via the side plate 52c, the lower plate 52b and the pressing portion 18. As shown in FIG. Therefore, a pressure difference is generated between the two

pads

12 and 14, and when the differential pressure sensor 20 detects the pressure difference, vital vibration is detected.

On the other hand, in the N case, when external vibration is applied to the module, the lower part of the pressing portion 16a contacts or strongly contacts the pad 12. Then, the contact area between the two pads 12 and the pressing portion 16a and the contact area between the

pads

14 and 18 become close to each other. The external vibration transmitted to the

pads

12 and 14 has a surface pressing structure for both the

pressing portions

16a and 18. FIG. Therefore, vibration transmitted to the

pads

12 and 14 is suppressed. Since the differential pressure sensor 20 detects the pressure difference between the two

pads

12 and 14, the output signal of the differential pressure sensor 20 corresponding to disturbance vibration can be further reduced. Therefore, it becomes possible to detect the vital vibration superimposed on the disturbance vibration. 13(b), a pressing portion 16 having the same shape as the pressing portion 18 in FIG. 13(b) is provided between the pad 12 and the upper plate 52a, and is the same as the pressing portion 16a in FIG. A shaped pressing portion may contact the lower plate 52b, and a pressing portion having the same shape as the pressing portion 16b in FIG. 13(b) may contact the pad 14 and the lower plate 52b. In short, the

pressing portions

16a, 16b, 18, the

pads

12, 14, and the separator 50 may be arranged upside down.

[Modification 3 of Embodiment 2]
[Structure in which the lower plate 52b of the housing is omitted]
14 is a cross-sectional view of a module in Modification 3 of Embodiment 2. FIG. As shown in FIG. 14, the housing 52 does not have a lower plate 52b, and has a lower plate 52d extending outward from the lower ends of the side plates 52c. In Modified Example 3 of Example 2, the pressing portion 18 is not supported by the housing 52 because the lower plate 52b is not provided. Since the module is embedded in the concave portion of the seat cushion, the pressing portion 18 is supported by the seat cushion 44 (see FIG. 3) made of urethane or the like, which is the bottom portion.

The portion below the plate member 55 is entirely embedded in the sheet as shown in FIGS. 3, 22(a) and 22(b). The seat is formed with a recess into which this module is received, and the module is mounted within the recess. A lid of the sheet is provided on the sheet, including the recess. Drivers and passengers sit on the seats. This configuration may be applied to all embodiments.

In the S case, mainly the passenger's vital vibration is transmitted to the upper plate 52a via the plate-like member 55 and the shaft core member 54. The pressing portion 16a abuts and is fixed to the pad 12, but the upper surface of the pressing portion 16a is separated from the upper plate 52a. On the other hand, the pressing portion 16b is in contact with the four corners of the pad 12 or in a ring shape. Therefore, in the pad 12, the

pressing portions

16a and 16b have a surface pressing structure, and propagation of vital vibration to the pad 12 is suppressed. The vital vibration is transmitted downward through the side plate 52c. The pressing portion 18 is supported by the recessed portion of the sheet, that is, the bottom surface of the foaming resin. Therefore, the vital vibration is transmitted from the side plate 52c to the pressing portion 18 through the foamed resin, and the pressing portion 18 presses the pad 14. As shown in FIG. In this manner, the vital vibration transmitted to the pad 12 is suppressed, and the pressing portion 18 abuts the central portion of the lower surface 14 b , so the vital vibration is transmitted to the pad 14 . Therefore, a pressure difference is generated between the two

pads

12 and 14, and the differential pressure sensor 20 can detect vital vibration.

On the other hand, in the N case, external vibrations are applied to the module from below and above. At this time, since the vibration is large, the pressing portion 16a abuts against the upper plate 52a, and both the pressing portion 16b and the pressing portion 16a that press the peripheral portion have a surface pressing structure. Further, the pressing portion 18 supported by the bottom surface of the foamed resin has a surface pressing structure. Since the contact area between the two pads 12 and the

pressing portions

16a and 16b and the contact area between the pad 14 and the pressing portion 18 are close to each other, the vibrations entering both the

pads

12 and 14 are suppressed. The pressure difference between

pads

12 and 14 is reduced. The output signal of the differential pressure sensor 20 becomes smaller and the output signal of the preamplifier does not saturate. Vital vibration is superimposed on the disturbance vibration, and the vital vibration can be detected as a vital signal by the signal processing shown in FIG. In order to transmit vital vibrations from the human body to the upper plate 52a, it is preferable to include the plate-like member 55 and the shaft core member 54. As shown in FIG. A pressing portion 16 having the same shape as the pressing portion 18 in FIG. 14 is provided between the pad 12 and the upper plate 52a, and pressing portions having the same shape as the

pressing portions

16a and 16b in FIG. may be provided. In short, the

pressing portions

16a, 16b, 18, the

pads

12, 14, and the separator 50 may be arranged upside down.

FIG. 15 is a cross-sectional view of a module according to Example 3. FIG. 16(a) to 16(d) are plan views of a module according to Example 3. FIG. FIG. 16(a) illustrates the upper plate 52a and the plate member 56. FIG. FIG. 16(b) illustrates the pad 12, the

pressing portions

16a and 16b, and the side plate 52c. FIG. 16(c) illustrates

pads

12, 14 and side plate 52c. FIG. 16(d) illustrates the pad 14, the pressing portion 18 and the lower plate 52b. In Example 3,

pads

12 and 14 correspond to the first and second members, respectively. The upper surface 12a and the lower surface 12b of the pad 12 respectively correspond to the first and second surfaces facing each other. Upper surface 14a and lower surface 14b of pad 14 correspond to third and fourth surfaces facing each other, respectively. The pressing portion 16a and the plate member 56 correspond to the first pressing portion. The pressing portion 18 and the lower plate 52b correspond to the second pressing portion. The pressing portion 16b and the upper plate 52a correspond to the second pressing portion. The side plate 52c corresponding to the third pressing portion corresponds to the supporting member.

　As shown in Figs. 15 to 16(d), the plate member 55 and the shaft core member 54 are not provided. An opening 57 is provided in the central portion of the upper plate 52a. A plate member 56 is provided in the opening 57 . The peripheries of the upper plate 52a and the plate-like member 56 are separated. A pressing portion 16 a is provided between the plate member 56 and the pad 12 . The pressing portion 16a and the upper surface 12a are in contact with each other, and the pressing portion 16a and the plate-like member 56 are also in contact with each other, regardless of the force applied from the pressing portion 16a toward the pad 12 . The pressing portion 16b is located on the peripheral edge portion of the upper surface 12a between the upper surface 12a and the upper plate 52a, is in contact with the upper surface 12a and the upper plate 52a, and is separated from the pressing portion 16a. The pressing portions 16 b are provided at the four corners of the pad 12 . As long as the pressing portion 16b is provided on the peripheral portion of the upper surface 12a, it may be provided at each of the four corners, or may be provided in a ring shape. Furthermore, they may be provided on a pair of opposing sides of the upper surface 12a. The lower surface 12b of the pad 12 and the upper surface 14a of the pad 14 are in contact with each other. The pressing portion 18 is provided between the pad 14 and the lower plate 52b and is in contact with the pad 14 and the lower plate 52b. Other configurations are the same as those of the second embodiment, and description thereof is omitted.

The operation of the module of Example 3 will be explained. First, in case S, the case where vital vibration is transmitted from the human body 60 to the module 10 will be described. Since the pressing portion 16b holds the peripheral portion of the pad 12, it seems that the propagation of vibration to the pad 12 is suppressed. The pressing portion 16a and the pressing portion 16b move separately. The vital vibration is transmitted to the central portion of the upper surface 12a of the pad 12 from the plate member 56 and the pressing portion 16a. The pressing portion 16a has a point pressing structure. Since the central portion of the upper surface 12a has high leaf spring properties, the pressure in the space 11 changes sensitively due to vital vibrations. Since the pressing portion 16b is in contact with the peripheral portion of the pad 12, vibration is less likely to be transmitted from the pressing portion 16b to the pad 12. FIG.

On the other hand, when the pad 12 is pushed, the pad 14 is pushed by the pushing portion 18, but since the pushing portion 18 is in contact with the peripheral portion 64 from the central portion of the lower surface 14b, the responsiveness of the pad 14 is suppressed and the space 13 is filled. Pressure does not change sensitively. Therefore, since a pressure difference occurs between the

pads

12 and 14, the differential pressure sensor 20 can detect vital vibrations.

Next, a case where disturbance vibration is transmitted to the module 10 in case N will be described. When a large external vibration is applied to the module, this external vibration is propagated from below to the lower plate 52b, and the pressing portion 18 presses the pad 14 with a surface pressing structure. On the other hand, in the upper plate 52a, external vibration is applied from the side plate 52c and the periphery of the seat. The pressing portion 16a and the pressing portion 16b have a surface pressing structure. Therefore, the

pads

12 and 14 are prevented from propagating disturbance vibrations. The pressure difference between

pads

12 and 14 is small, and the output signal of differential pressure sensor 20 is small. Therefore, the output signal of the preamplifier is not saturated, and vital vibration superimposed on disturbance vibration can be detected.

[Experiment 2]
Using the module of Example 3, changes in pressure in

spaces

pads

The dimensions of each member are as follows.
Plate member 56: Diameter φ=25 mm, Z=3 mm
Upper plate 52a: X×Y×Z=55 mm×55 mm×3 mm
Aperture 57: Diameter φ=30 mm
Lower plate 52b: X×Y×Z=55 mm×55 mm×3 mm
Side plate 52c: X, Y=55 mm (width)×5 mm (thickness), Z=19.5 mm
Holes (X, Y×Z=8 mm×15 mm) for

Tubes

26 and 27 are Formed on One Surface of Side Plate 52c The upper plate 52a, the lower plate 52b and the side plate 52c are bonded using an adhesive having a thickness of 0.1 mm.
Pressing portion 16a: Diameter φ=15 mm, Z=2 mm
Pushing portion 16b: X×Y×Z=5 mm×5 mm×2 mm
Pressing portion 18: X x Y x Z = 25 mm x 25 mm x 1 mm
Pads 12, 14: X x Y x Z = 40 mm x 40 mm x 8 mm, thickness is 1 mm

A counterbore was provided in the center of a floor cushion of X x Y x Z = 300 mm x 300 mm x 60 mm made of urethane, and the created module 10 was installed in the counterbore. The counterbore is covered with urethane, which is the same material as the cushion. As the vital vibration, a weak vibration corresponding to a vital signal was applied to the lid by lightly pressing the upper surface of the lid with a finger. As disturbance vibration, strong vibration corresponding to disturbance vibration was applied to the lid by hitting the lid strongly with a hand. The pressure in

spaces

11 and 13 of

pads

12 and 14 was detected by a detector.

FIG. 17 shows the results of Experiment 2 and shows the output signal of the detector against time. As shown in FIG. 17, the output signal from the pad 12 is larger than the output signal from the pad 14 in the period 70, which is the S case and a small vibration such as a vital signal occurs. Therefore, even if the differential pressure sensor 20 is used to cancel pressure changes in the

pads

12 and 14, it is considered possible to detect vital vibrations. In the period 71, the output signals of the

pads

12 and 14 are different, but have substantially the same magnitude over the entire area. As a result, when the differential pressure sensor 20 is used to detect the pressure changes of the

pads

12 and 14, the pressures of the

pads

12 and 14 are canceled to some extent, and the output signal corresponding to the disturbance vibration can be reduced. Therefore, the vital vibration superimposed on this disturbance vibration can be detected.

According to the third embodiment, the pressing portion 16a is in contact with the central portion of the upper surface 12a of the pad 12. The pressing portion 18 contacts at least the central portion of the lower surface 14b of the pad 14, and the area of contact of the pressing portion 18 with the lower surface 14b is larger than the area of contact of the pressing portion 16a with the upper surface 12a. Vital vibrations are thus transmitted mainly to the pad 12 . The area of the pressing portion 18 in contact with the lower surface 14b is preferably twice or more, more preferably 4 times or more, the area of the pressing portion 16a in contact with the upper surface 12a. The area of the pressing portion 16a in contact with the upper surface 12a is preferably 1/3 or less of the planar area of the pad 12, and more preferably within the range of 1/32 to 1/8. The pressing portion 16a and the plate-like member 56 and the pressing portion 16b and the upper plate 52a move independently of each other.

Also, the lower surface 12b of the pad 12 and the upper surface 14a of the pad 14 are in contact with each other. As a result, when external vibrations are applied to the module, the vibrations are easily transmitted to both the

pads

12 and 14 .

The upper surface of the upper plate 52a and the upper surface of the plate-like member 56 may be positioned on the same plane. may be located. The plate member 56 and the pressing portion 16a may be integrally formed, or may be formed separately and joined by an adhesive or the like. The upper plate 52a and the pressing portion 16b may be integrally molded, or may be formed separately and joined by an adhesive or the like. The upper plate 52a, the plate member 56, the

pressing portions

16a and 16b may be arranged on the lower surface 14b side of the pad 14, and the lower plate 52b and the pressing portion 18 may be arranged on the upper surface 12a of the pad 12. In short, the

pressing portions

16a, 16b, 18, the

pads

12, 14, the separator 50, the upper plate 52a, the plate member 56 and the lower plate 52b may be arranged upside down.

[Single pad structure: Suppresses external vibration with the housing]
18A is a cross-sectional view of a module according to Example 4, and FIGS. 18B and 18C are plan views of the module according to Example 4. FIG. FIG. 18(b) illustrates the upper plate 52a and the pressing portion 16. FIG. FIG. 18(c) illustrates the pad 12, the pressing portion 16 and the side plate 52c. In Example 4, the pad 12 corresponds to the member. The upper surface 12a and the lower surface 12b of the pad 12 respectively correspond to the first and second surfaces facing each other. The pressing portion 16 and the lower plate 52b correspond to the first pressing portion and the second pressing portion, respectively. The side plate 52c and the top plate 52a correspond to the housing.

As shown in FIGS. 18(a) to 18(c), one pad 12 is provided. The pressing portion 16 is in contact with the central portion of the upper surface 12 a of the pad 12 . An opening 57 is provided in the central portion of the upper plate 52a. The pressing portion 16 passes through the opening 57 and is in contact with or fixed to the central portion of the plate-like member 55 . The lower surface 12b of the pad 12 is in contact with the lower plate 52b. The side plate 52c connects the periphery of the upper plate 52a and the periphery of the lower plate 52b, surrounds the pad 12, and is separated from the pad 12. As shown in FIG. The space 11 within the pad 12 is connected via a tube 26 to the sensor 20a. Sensor 20 a detects the pressure in space 11 . Other configurations are the same as those of the first embodiment, and description thereof is omitted.

In Example 4, the pressing portion 16 is in contact with the central portion of the upper surface 12 a of the pad 12 . As a result, when vital vibration is transmitted from the pressing portion 16 to the pad 12, the sensor 20a can accurately detect the vital vibration. Note that the housing 52 is preferably a rigid body. The housing 52 is also generally hexahedral, with each face supporting a respective peripheral edge. Therefore, both of them form a surface-pressing structure, and the effect of both can suppress the intrusion of external vibration such as road noise into the pad 12 . Therefore, in the S case, when most of the vital vibrations occur, and in the N case, when external vibrations are added to the vital vibrations, the propagation of the disturbance vibrations to the pad 12 can be greatly suppressed. Therefore, vital vibration can be detected.

The area of the pressing portion 16 in contact with the upper surface 12a is preferably 1/4 or less of the planar area of the pad 12, more preferably 1/16 or less. Since the housing 52 surrounds the pads 12 , external vibrations are less likely to be transmitted to the pads 12 .

[Experiment 3]
Using the module of Example 4, changes in pressure in

spaces

11 and 13 due to vital vibration and disturbance vibration were detected. The material of pad 12 is polyethylene. Other members were made by cutting an acrylic plate. An instant adhesive was applied to the cut members so as to have a thickness of 0.1 mm, and then the members were joined.

The dimensions of each member are as follows.
Plate member 55: Diameter φ=25 mm, Z=3 mm
Upper plate 52a: X×Y×Z=55 mm×55 mm×3 mm
Aperture 57: Diameter φ=30 mm
Lower plate 52b: X×Y×Z=55 mm×55 mm×3 mm
Side plate 52c: X, Y=55 mm (width)×5 mm (thickness), Z=3 mm
A hole (X, Y×Z=8 mm×15 mm×3 mm) for the tube 26 is formed in one surface of the side plate 52c.
Pressing portion 16a: Diameter φ=15 mm, Z=2 mm
Pad 12: X x Y x Z = 40 mm x 40 mm x 8 mm, thickness is 1 mm

A counterbore was provided in the center of a floor cushion of X x Y x Z = 300 mm x 300 mm x 60 mm made of urethane, and the created module 10 was installed in the counterbore. The module of Example 4 was installed in the car seat of the vehicle, and the vital signals of the passenger seated in the car seat were detected.

FIG. 19(a) is a diagram showing the output signal of the sensor 20a with respect to time in Experiment 3, and FIG. 19(b) is a diagram showing a spectrum obtained by Fourier transforming the output signal in period 72 of FIG. 19(a). . In FIG. 19A, a period 72 is a period during which the vehicle passes through a flat road surface, and a period 73 is a period during which the vehicle passes over an uneven road surface with traces of construction. During the period 73, the noise of the output signal is large, but during the period 72, the noise of the output signal is small. As shown in FIG. 19(b), when the output signal in the period 72 is Fourier transformed, a peak 74 of the signal corresponding to respiration and a peak 75 of the signal corresponding to the pulse are obtained. In period 73, peaks corresponding to respiration and pulse were not observed. In this way, it is possible to detect vital signals corresponding to respiration and pulse, which depend on road surface conditions. It can also monitor road surface conditions (eg, ruts, construction marks, cracks, natural undulations, whether it is paved, etc.).

According to the fourth embodiment, the side plate 52c and the upper plate 52a (housing) surround the pad 12 together with the lower plate 52b (second pressing portion) and surround the pad 12 apart from it. Further, an opening 57 is provided in the upper plate 52a, and the side surface of the opening 57 and the pressing portion 16 are separated. As a result, the portion of the housing 52 made up of the side plate 52c and the upper plate 52a suppresses the transmission of external vibrations to the pad 12. As shown in FIG. Therefore, detection accuracy of vital vibration can be improved.

The upper plate 52a (part) of the housing 52 is provided apart from the upper surface 12a of the pad 12 and has an opening 57 through which the pressing portion 16 penetrates. Since the housing 52 can surround the pad 12 from above, the detection accuracy of vital vibration can be further improved.

[Modification 1 of Embodiment 4]
20 is a cross-sectional view of a module in Modification 1 of Embodiment 4. FIG. As shown in FIG. 20, a pressing portion 18 is provided between the lower surface 12b and the lower plate 52b. The pressing portion 18 contacts the pad 12 and the lower plate 52b. In Modification 1 of Embodiment 4, the pressing portion 18 and the lower plate 52b correspond to the second pressing portion. The area of the pressing portion 18 in contact with the lower surface 12b is preferably smaller than the area of the pressing portion 16 in contact with the upper surface 12a, preferably twice or more, and more preferably four times or more.

[Horizontal arrangement structure of two overlapping pads]
Example 5 is an example regarding module installation. 21(a) is a cross-sectional view of the module in Comparative Example 5, and FIG. 21(b) is a cross-sectional view of the module in Example 5. FIG. 21(a) and 21(b), the downward direction is the direction of gravity, the vertical direction, and is the centerline 67 of

pads

12 and 14. FIG.

As shown in FIG. 21A, in Comparative Example 5, the upper surface 12a and the lower surface 12b of the pad 12, and the upper surface 14a and the lower surface 14b of the pad 14 are inclined with respect to the vertical direction. The direction of the force 68 from the pressing portion 16 to the pad 12 presses the center of the pad 12 and is inclined with respect to the normal direction Z direction of the upper surface 12a and the lower surface 12b. As a result, the force 68 is divided into a force component 68a in the -Z direction and a force component 68b in the X direction. As already mentioned, it is preferable to press the center of

pads

12 and 14 as much as possible in order to detect vital vibrations. However, since the force 68 is inclined with the center of the pad 12 as the starting point, the force component 68a that effectively acts is weakened.

As shown in FIG. 21(b), in Example 5, the upper surface 12a and the lower surface 12b of the pad 12, and the upper surface 14a and the lower surface 14b of the pad 14 are substantially orthogonal to the vertical direction and arranged horizontally. In order to efficiently apply force to

pads

12 and 14, the direction of applied force is preferably perpendicular to the surfaces of

pads

12 and 14. FIG.

FIGS. 22(a) and 22(b) are cross-sectional views of a car seat in which the module in Example 5 is installed. FIG. 22(a) is a cross-sectional view of the car seat 41 cut in the left-right direction, and FIG. 22(b) is a view of the car seat 41 cut in the front-rear direction. As shown in FIGS. 22(a) and 22(b), the upper surface of the seat cushion 44 of the car seat 41 is inclined downward toward the rear. This is to protect passengers in the event of a head-on collision of the vehicle. The module 10 is installed horizontally so that the top and bottom surfaces of the

pads

12 and 14 are substantially perpendicular to the vertical direction. As a result, the passenger's vital vibrations are applied perpendicularly to the surfaces of the

pads

12 and 14, improving detection accuracy. It should be noted that the term “substantially perpendicular to the vertical direction” means that an inclination of about ±10° or ±5° is allowed with respect to a horizontal plane perpendicular to the vertical direction.

[Human sensor]
Embodiment 6 is an example of a seating determination device that determines whether an object such as 40 kg of rice is placed on the front passenger seat or the driver's seat, whether the object is a person or luggage. It is possible to suppress the sounding of the alarm that the seat belt is not fastened when rice is placed. In addition, it is possible to prevent the engine from starting even when no passenger is on board during automatic driving. The modules of Examples 1 to 5 are installed in a car seat as shown in FIG. 3 or FIGS. It may be determined whether Furthermore, by installing a temperature sensor in the interior of the vehicle, it is possible to make the following determinations and alarm notifications. For example, the determination device uses the human sensor of the sixth embodiment to determine whether a person is inside the vehicle. The determination device determines that there is a person inside the vehicle, and issues an alarm when the room temperature of the vehicle exceeds, for example, 20° C. and the vehicle has been parked for longer than a predetermined period of time. The determination device may notify the alarm outside the vehicle by sound, or may notify the alarm to the driver's portable device using wireless communication means such as BLE (Bluetooth (registered trademark) Low Energy).

[Experiment 4]
The module used in Experiment 2 of Example 3 was placed in a cushion made of urethane on the rear seat of the vehicle. The output signal of the differential pressure sensor 20 was acquired when the passenger sat on the cushion and when 40 kg of rice was placed. Reference vital signs were acquired from the passenger's chest. The vehicle was driven at a speed of 40 km/h when acquiring the passenger's vital signs, and the vehicle was driven at a speed of 20 km/h when the rice was placed. The sampling frequency is 133.3 Hz, the number of Fourier transform blocks is 2048, the calculation method is 30-second average, and the upper limit frequency is 0.5 Hz. More specifically, when the sampling frequency is 133.3 Hz and the number of Fourier transform blocks is 2048, the measurement time is 15.4 seconds. Respiration rate varies greatly among individuals, and the measurement time of 15.4 seconds is too short, so the average of 30 seconds was analyzed. In addition, since the upper limit frequency was set to 0.5 Hz, the maximum number of breaths per minute was set to 30 times, and spectral components above 0.5 Hz were set not to be regarded as respirations.

FIGS. 23(a) to 23(d) are diagrams showing the output signal of the differential pressure sensor with respect to time in Experiment 4. FIG. Solid lines in FIGS. 23(a) and 23(b) indicate the output signal of the differential pressure sensor 20 when the passenger (human body) is seated. The reference signal ref is a reference vital signal that is measured simultaneously with the acquisition of the output signal of the differential pressure sensor 20 and acquired from the chest of the passenger. Acquisition of the output signal was performed twice in FIGS. 23(a) and 23(b). Solid lines in FIGS. 23(c) and 23(d) indicate the output signal when 40 kg of rice is placed on the cushion. The reference signal ref is a reference vital signal obtained from the chest of the passenger who boarded together. Acquisition of the output signal was performed twice as shown in FIGS. 23(c) and 23(d).

As shown in FIGS. 23(a) and 23(b), in the human body, the output signal of the differential pressure sensor 20 shows the same tendency as ref. On the other hand, as shown in FIGS. 23(c) and 23(d), with rice, the output signal of the differential pressure sensor 20 exhibits movements that are not related to ref.

In FIGS. 23(a) to 23(d), the period 76 is divided into 7 sections. Each section contains 2048 points of data. Fourier transform was performed for each interval and spectral analysis was performed. As a result, seven spectra were obtained for each of FIGS. 23(a) to 23(d).

FIGS. 24(a) to 24(g) are diagrams showing the results of the spectrum analysis of FIG. 23(a) for the first human body in Experiment 4. FIG. FIGS. 25(a) to 25(g) are diagrams showing the results of the spectrum analysis of FIG. 23(b) for the second time on the human body. The solid line is the spectrum of the output signal of the differential pressure sensor 20, and the dotted line is the spectrum of the reference signal ref. As shown in FIGS. 24(a) to 25(g), in the spectrum of the reference signal, a peak in the respiratory component is observed near 0.2 to 0.3 Hz as indicated by arrow 58. FIG. 24(a), 24(b), 24(d)-24(g), 25(a)-25(c), 25(e) and 25(f), the difference In the spectrum of the output signal of the pressure sensor 20, a peak considered to be a respiratory component can be observed in the vicinity of the arrow 58 of the reference signal ref.

FIGS. 26(a) to 26(g) show the results of the spectral analysis of FIG. 23(c) for the first rice in Experiment 4. FIG. FIG. 27(a) to FIG. 27(g) are diagrams showing the results of the spectral analysis of FIG. 23(d) for the second rice. The solid line is the spectrum of the output signal of the differential pressure sensor 20, and the dotted line is the spectrum of the reference signal ref. As shown in FIGS. 26(a) to 27(g), in the spectrum of the reference signal, a peak in the respiratory component is observed near 0.2 to 0.3 Hz as indicated by arrow 58. FIG. However, in the spectrum of the output signal of the differential pressure sensor 20, no peak that is considered to be a respiratory component can be observed in the vicinity of the arrow 58 of the reference signal ref.

An example of a flow in which the processing unit 34 cooperates with software and functions as a determination unit that determines whether or not the passenger is seated in the car seat 41 will be described. 28(a) and 28(b) are flowcharts showing the processing of the processing unit in the sixth embodiment. As shown in FIG. 28(a), the processing unit 34 acquires the output signal of the differential pressure sensor 20 for a predetermined period (step S10). The processing unit 34 Fourier-transforms the acquired output signal (step S12). The processing unit 34 determines whether or not there is a peak in a specific frequency range (for example, 0.2 Hz to 0.5 Hz) in the Fourier-transformed spectrum (step S14). When Yes, the processing unit 34 determines that the passenger is seated in the car seat 41 (step S16). When No, the processing unit 34 determines that the passenger is not seated in the car seat 41 (step S18). Then exit. Thus, the processing unit 34 can determine whether or not the passenger is seated in the car seat 41 .

As shown in FIG. 28(b), the processing unit 34 sets i=0 and j=0 (step S20). The processing unit 34 sets i=i+1 (step S22). The processing unit 34 performs steps S10, S12 and S14 as in FIG. 28(a). When Yes in step S14, the processing unit 34 sets j=j+1 (step S24). When No, the processing unit 34 does not perform step S24. The processing unit 34 determines whether i=n (step S26). n is a natural number of 2 or more and is set in advance. If No, the process returns to step S22. When Yes, the processing unit 34 determines whether j/n>k (step S28). k is a value greater than 0 and less than 1; When Yes, the processing unit 34 determines that the passenger is seated in the car seat 41 (step S30). When No, the processing unit 34 determines that the passenger is not seated in the car seat 41 (step S32). Then exit.

As shown in FIGS. 24(a) to 25(g), even if the passenger is seated in the car seat 41, there are cases where no peak occurs in a specific frequency range. In FIG. 28(b), the presence or absence of a respiratory component peak is determined in n different periods, and when the ratio j/n of peaks is greater than a predetermined ratio k, the passenger is seated in the car seat 41. determine that there is This makes it possible to more accurately determine whether the passenger is seated in the car seat 41 . Note that n and k may be changed depending on the situation. For example, when the vehicle is stopped, the disturbance vibration is small. Therefore, n is made small and k is made large. For example, when the vehicle is running fast, the disturbance vibration is large. Therefore, n is increased and k is decreased.

According to the sixth embodiment, a

module including pads

12 and 14 and

pressing portions

16 and 18 is provided in a car seat 41 of a vehicle, and the determination portion determines whether the passenger is seated on the seat based on the output of the differential pressure sensor 20. determine whether or not there is This makes it possible to accurately determine whether or not the passenger is seated on the car seat 41 . The module 10 can be installed in the driver's seat, passenger's seat or rear seat of the vehicle.

When the subject sits on the seat, the buttocks are the most suitable source of vibration such as vital signs. Therefore, as shown in FIG. 4, it is preferable that the

pads

12 and 14 are provided so as to overlap the human body part (for example, the right buttock or the left buttock) to which a load is applied, such as the buttocks of the subject. The

pads

12 and 14 may be provided so as to overlap the vibration source such as the vitals of the subject's thighs.

FIG. 29 is a flow chart showing the detection method in the sixth embodiment. As shown in FIG. 29, the modules of Examples 1 to 3 and their modifications are prepared by being embedded in the seat of a four-wheeled vehicle (step S40). At this time, at least one of the

pads

12 and 14 adjusts the vibration transmitted to the pad by the pressing portion that abuts on the pad (step S42). The

pad

12 or 14 may be arranged so that the vital vibrations of the occupant are primarily transmitted. The differential pressure sensor 20 detects the difference between the gas pressure in the pad 12 and the gas pressure in the pad 14 (step S44). The processing unit 34 analyzes the pressure difference between the pads 12 and 14 (step S46). The processing unit 34 determines the state of vital vibration of the passenger (step S48). In step S48, it may be determined whether the object placed on the sheet is a person or a load.

In the sixth embodiment, the vital vibration of the passenger is detected and the state of the vital vibration is determined. The state of the motor may be determined.

In International Publication No. 2020/158952, a capacitance sensor, an electret condenser microphone, a piezoresistive sensor, a differential transformer, or the like may be used instead of the piezoelectric element.

Also, as can be seen from the description so far, in Examples 1 to 6, vital vibration was mainly described as the vibration detected by the processing unit 34 from the

pads

12 and 14 . However, as described with reference to FIGS. 12, 17 and 19A, road noise is detected because the saturation of the road noise is suppressed. Therefore, the processing unit 34 may detect road noise and perform arithmetic processing on the road noise. The vehicle control device may determine the fuel consumption of the vehicle or control the speed of the vehicle from the vibration of this road noise. Furthermore, the processing unit 34 may detect vibration of the vehicle drive motor. For example, the processing unit 34 may extract an abnormal sound of the motor for driving the wheels, and the control device of the vehicle may control the vehicle to decelerate or stop when the abnormal sound is detected.

Also, based on the road noise detected by the processing unit 34, the vehicle control device may notify the driver of the current road surface condition or fuel consumption, or may guide the driver to another route in conjunction with the navigation system. Furthermore, the vehicle control device may store the detected road noise information in the cloud. The vehicle control device may notify the driver of the fuel consumption or the degree of fatigue due to driving when traveling on the estimated road surface obtained from the cloud, propose a driving route according to it, and prevent accidents. You may make an announcement for

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations can be made within the scope of the gist of the present invention described in the scope of claims. Change is possible.

In addition, the following features are further disclosed with respect to the above description.
(Feature 1)
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
It is positioned at the center of the first surface when viewed from the lamination direction of the first member and the second member, and is in contact with the first surface when no force is applied in the direction of the first surface or when the force is small. However, when the force is not applied or when the force is small, the area in contact with the first surface is small, and when the force is large, the area in contact with the first surface is reduced. an enlarged first pressing portion;
a second pressing portion in contact with at least a central portion of the fourth surface;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
A biological information detection device comprising:
(Feature 2)
The biological information detection device according to feature 1, wherein the surface of the first pressing portion facing the first surface has a central portion that protrudes toward the first surface from a peripheral portion.
(Feature 3)
The biological information detection device according to feature 1, wherein the first surface has a central portion that protrudes toward the first pressing portion with respect to the peripheral portion.
(Feature 4)
4. The biological information detection device according to any one of features 1 to 3, wherein the second surface and the third surface are in contact with each other.
(Feature 5)
the module comprises a separator provided between the second surface and the third surface in contact with the peripheral edges of the second surface and the third surface;
5. The biometric information detecting device according to any one of features 1 to 4, wherein the second surface and the third surface are separated by the separator.
(Feature 6)
6. The biological information detection according to any one of features 1 to 5, wherein the module includes a support member that surrounds the first member and the second member and connects the first pressing portion and the second pressing portion. Device.
(Feature 7)
The module is
a plate-shaped member provided away from the first pressing portion on a side opposite to the first member with respect to the first pressing portion;
an axial core member connecting the central portion of the plate-like member and the central portion of the first pressing portion and having a plane area smaller than that of the plate-like member;
The biological information detection device according to any one of features 1 to 6, comprising:
(Feature 8)
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a third member provided away from the first surface on the side opposite to the second member with respect to the first member;
Positioned in the center of the first surface between the first surface and the third member, when no force is applied from the third member in the direction of the first surface or when the force is small, the first It does not touch either one of the first member and the third member, but touches the one member when the force increases, or touches the one member when the force is not applied or when the force is small. a first pressing portion having a small area and having a larger area in contact with the one member as the force increases;
a second pressing portion in contact with at least a central portion of the fourth surface;
a third pressing portion located at the peripheral edge of the first surface between the first surface and the third member and in contact with the first surface and the third member without the force;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
A biological information detection device comprising:
(Feature 9)
The biological information detection device according to feature 8, wherein the module includes a support member that surrounds the first member and the second member and connects the third member and the second pressing portion.
(Feature 10)
the module comprises a separator provided between the second surface and the third surface in contact with the peripheral edges of the second surface and the third surface;
10. The biological information detection device according to feature 8 or 9, wherein the second surface and the third surface are separated by the separator.
(Feature 11)
The module is
a plate-shaped member provided away from the third member on the side opposite to the first member with respect to the third member;
a shaft core member that connects the central portion of the plate member and the central portion of the third member;
The biological information detection device according to any one of features 8 to 10, comprising:
(Feature 12)
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion in contact with the central portion of the first surface;
a second pressing portion that is in contact with at least a central portion of the fourth surface and has an area in contact with the fourth surface that is larger than an area in which the first pressing portion is in contact with the first surface;
a third pressing portion in contact with the peripheral portion of the first surface;
a support member that surrounds the first member and the second member and connects the second pressing portion and the third pressing portion;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
A biological information detection device comprising:
(Feature 13)
13. The biological information detection device according to feature 12, wherein the first pressing portion is separated from the third pressing portion.
(Feature 14)
14. The biological information detection device according to feature 12 or 13, wherein the second surface and the third surface are in contact with each other.
(Feature 15)
a bag-shaped member having a first surface and a second surface facing each other and filled with gas;
a first pressing portion in contact with the central portion of the first surface;
a second pressing portion in contact with at least a central portion of the second surface;
a housing connected to said second pusher, surrounding said member away from said member and spaced from said first pusher;
a module comprising
a detector for detecting gas pressure within the member;
A biological information detection device comprising:
(Feature 16)
16. Biometric information according to feature 15, wherein the housing is provided on a side of the member opposite to the second pressing portion, away from the first surface, and has a portion having an opening through which the first pressing portion passes. detection device.
(Feature 17)
17. According to feature 15 or 16, the module includes a plate-like member provided on the side of the member opposite to the second pressing portion, away from the first surface, and having a center portion in contact with the first pressing portion. Biometric information detection device.
(Feature 18)
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion in contact with at least a central portion of the first surface;
a second pressing portion in contact with at least a central portion of the fourth surface;
a separator provided between the second surface and the third surface in contact with peripheral edge portions of the second surface and the third surface;
wherein the second surface and the third surface are separated by the separator; and
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
A biological information detection device comprising:
(Feature 19)
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion in contact with at least a central portion of the first surface;
a second pressing portion in contact with at least a central portion of the fourth surface;
a plate-shaped member provided away from the first pressing portion on a side opposite to the first member with respect to the first pressing portion;
an axial core member connecting the central portion of the plate-like member and the central portion of the first pressing portion and having a plane area smaller than that of the plate-like member;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
A biological information detection device comprising:
(Feature 20)
15. The biological information detection device according to any one of features 1 to 14, wherein the first surface, the second surface, the third surface, and the fourth surface are arranged in a direction substantially perpendicular to the vertical direction.
(Feature 21)
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion in contact with at least a central portion of the first surface;
a second pressing portion in contact with at least a central portion of the fourth surface;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
with
The biological information detecting device, wherein the first surface, the second surface, the third surface and the fourth surface are arranged in a direction substantially orthogonal to a vertical direction.
(Feature 22)
22. The biological information detection device according to feature 21, wherein the second surface and the third surface are in contact with each other.
(Feature 23)
23. The biometric information detection device according to feature 21 or 22, wherein the module is installed in a seat of a vehicle.
(Feature 24)
the biological information detection device according to any one of features 1 to 14 and 18 to 23;
a determination unit that determines, based on the output of the detector, whether or not an occupant is seated in the vehicle seat provided with the module;
A seating determination device.
(Feature 25)
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion in contact with at least a central portion of the first surface;
a second pressing portion in contact with at least a central portion of the fourth surface;
a module provided in the vehicle seat, comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
a determination unit that determines whether or not the passenger is seated on the seat based on the output of the detector;
A seating determination device.
(Feature 26)
a first bag-shaped member filled with gas; a second bag-shaped member placed under the first member and filled with gas; and a first pressing portion abutting on an upper surface of the first member. , a second pressing portion that abuts on the lower surface of the second member, a first tube that communicates with the first member, a second tube that communicates with the second member, and the first tube and the second tube. and a differential pressure sensor that detects a difference between the gas pressure in the first member and the gas pressure in the second member via at least the first member, the second member, preparing the first pressing portion and the second pressing portion by embedding them in a sheet;
At least one of the first member and the second member absorbs vibration transmitted to the at least one member by a pressing portion that abuts on at least one of the first pressing portion and the second pressing portion. adjust and
A sensing method for detecting a difference between the gas pressure in the first member and the gas pressure in the second member.
(Feature 27)
The module is embedded in the seat of a four-wheeled vehicle, and the vital vibration of the passenger, the vibration of the drive noise, or the vibration of the drive motor mainly propagates to either one of the first member and the second member. By analyzing the difference between the pressure of the gas in the first member and the pressure of the gas in the second member, the state of vital vibration of the passenger, the state of drive noise, or the drive motor 27. The sensing method of feature 26 for determining the state of the
(Feature 28)
28. The sensing method of feature 27, wherein the module is embedded in a seat of a four-wheeled vehicle and determines whether an object placed on the seat is a person or a package.

REFERENCE SIGNS LIST 10

module

11, 13, 21, 23

space

12, 14

pad

12a, 14a

upper surface

12b, 14b

lower surface

16, 16a, 16b, 18 pressing portion 20 differential pressure sensor 22 housing 24 diaphragm 25 sensor element 41 car seat 52 housing

52a Upper plate

52b Lower plate

52c Side plate 54

Axial member

55, 56 Plate member 57 Opening

Claims

a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion located in the central portion of the first surface when viewed from the stacking direction of the first member and the second member;
a second pressing portion in contact with at least a central portion of the fourth surface;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
with
The distance between the first surface and the fifth surface of the first pressing portion facing the first surface decreases from the peripheral portion toward the central portion,
A biological information detection device, wherein vibration can be transmitted between the first surface and the fifth surface.
The biological information detection device according to claim 1, wherein the surface of the first pressing portion facing the first surface projects toward the first surface from the peripheral portion at the central portion thereof.
The biological information detection device according to claim 1, wherein the first surface has a central portion that protrudes toward the first pressing portion with respect to the peripheral portion.
The biological information detection device according to any one of claims 1 to 3, wherein the second surface and the third surface are in contact with each other.
the module comprises a separator provided between the second surface and the third surface in contact with the peripheral edges of the second surface and the third surface;
The biological information detecting device according to any one of claims 1 to 3, wherein the second surface and the third surface are separated from each other by the separator.
4. The biological information according to any one of claims 1 to 3, wherein the module includes a support member that surrounds the first member and the second member and connects the first pressing portion and the second pressing portion. detection device.
The module is
a plate-shaped member provided away from the first pressing portion on a side opposite to the first member with respect to the first pressing portion;
an axial core member connecting the central portion of the plate-like member and the central portion of the first pressing portion and having a plane area smaller than that of the plate-like member;
The biological information detecting device according to any one of claims 1 to 3, comprising:
The biological information detecting device according to any one of claims 1 to 3, wherein the first surface, the second surface, the third surface and the fourth surface are arranged in a direction substantially perpendicular to the vertical direction.
The module is
a third member provided on the side opposite to the first member with respect to the first pressing portion;
a third pressing portion positioned at the peripheral edge portion of the first surface between the first surface and the third member and in contact with the first surface and the third member;
with
2. The biological information detecting device according to claim 1, wherein vibration can be transmitted between said first surface and said third member via said first pressing portion.
The biological information detection device according to claim 9, wherein the module includes a support member that surrounds the first member and the second member and connects the third member and the second pressing portion.
the module comprises a separator provided between the second surface and the third surface in contact with the peripheral edges of the second surface and the third surface;
The biological information detecting device according to claim 9 or 10, wherein the second surface and the third surface are separated by the separator.
The module is
a plate-shaped member provided away from the third member on the side opposite to the first member with respect to the third member;
a shaft core member that connects the central portion of the plate member and the central portion of the third member;
The biological information detection device according to claim 9 or 10, comprising:
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion in contact with at least a central portion of the first surface;
a second pressing portion in contact with at least a central portion of the fourth surface;
a plate-shaped member provided away from the first pressing portion on a side opposite to the first member with respect to the first pressing portion;
an axial core member connecting the central portion of the plate-like member and the central portion of the first pressing portion and having a plane area smaller than that of the plate-like member;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
A biological information detection device comprising:
a bag-shaped first member having a first surface and a second surface facing each other and filled with gas;
a bag-shaped second member having a third surface and a fourth surface facing each other, the third surface facing the second surface, and filled with a gas;
a first pressing portion in contact with at least a central portion of the first surface;
a second pressing portion in contact with at least a central portion of the fourth surface;
a module comprising
a detector that detects the difference between the gas pressure in the first member and the gas pressure in the second member;
with
The biological information detecting device, wherein the first surface, the second surface, the third surface and the fourth surface are arranged in a direction substantially orthogonal to a vertical direction.
The biological information detecting device according to claim 14, wherein the second surface and the third surface are in contact with each other.
The biological information detection device according to claim 14 or 15, wherein the module is installed inside a seat of a vehicle.
a biological information detection device according to any one of claims 1, 13 and 14;
a determination unit that determines, based on the output of the detector, whether or not an occupant is seated in the vehicle seat provided with the module;
A seating determination device.