Detection Equipment

Abstract

To provide a detection device with improved detection accuracy.SOLUTION: A detection device comprises: a bag-shaped first member 14 filled with gas; a bag-shaped second member 12 connected on the first member and filled with gas; a third member 18 that transmits vibration to the lower surface of the first member; a fourth member 16 that transmits vibration to the upper surface of the second member; and a detector that detects the difference between a gas pressure in the first member and a gas pressure in the second member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a detection device, for example, a detection device that detects vital vibrations. [Background technology]

[0002] There are known detection devices that detect vibrations of vital signs, such as the pulse wave and breathing of a subject (e.g., Patent Documents 1 to 6). It is known that a bag-shaped member filled with air is used to detect the vibrations of vital signs by detecting the air pressure inside the bag-shaped member (e.g., Patent Documents 4 and 5). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-219341 A [Patent Document 2] JP 2006-218068 A [Patent Document 3] JP 2006-42904 A [Patent Document 4] JP 2018-47862 A [Patent Document 5] JP 2009-82585 A [Patent Document 6] JP 2009-104599 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, highly sensitive vibration detectors are easily affected by disturbance vibrations. For example, it is difficult to detect vibrations of vital signs in an environment that includes large disturbance vibrations in the same band as the frequency components of the vibrations of vital signs. For example, vibrations such as drive noise occur inside a vehicle. Drive noise includes large disturbance vibrations in the same band as the frequency components of the vital signs information. As a result, the detected signal becomes saturated, making it impossible to detect vibrations of vital signs.

[0005] The present invention has been made in consideration of the above problems, and has an object to improve detection accuracy. [Means for solving the problem]

[0006] The present invention provides a gas pressure measuring device comprising: a bag-shaped first member filled with gas; a bag-shaped second member connected to the top of the first member and filled with gas; a third member that transmits vibrations to a lower surface of the first member; a fourth member that transmits vibrations to an upper surface of the second member; and a detector that detects a difference between the gas pressure in the first member and the gas pressure in the second member. The area of ​​the fourth member in contact with the upper surface of the second member is smaller than the area of ​​the second member in a plan view. It is a detection device.

[0007] In the above configuration, the fourth member may be larger than the second member in a plan view.

[0008] In the above configuration, the vibration of the subject's vital signs is transmitted from above the fourth member. R It can be configured as follows.

[0009] In the above configuration, vibrations of the subject's vital signs are transmitted from above the fourth member, and the area of ​​the fourth member in contact with the second member can be equal to or less than 1 / 2 of the area of ​​the second member in a plan view.

[0010] In the above configuration, an area where the third member is in contact with the lower surface of the first member can be equal to or larger than an area where the fourth member is in contact with the second member.

[0011] In the above configuration, a region where the fourth member is in contact with an upper surface of the second member may include a center of the second member in a plan view.

[0012] In the above configuration, in a planar view, the third member is larger than the first member, and the fourth member is larger than the second member, and the configuration can include a support member that is provided between the third member and the fourth member in a portion surrounding the first member and the second member in a planar view and connects the third member and the fourth member.

[0013] In the above configuration, the fourth member may include a first flat plate and a protruding portion that protrudes from the first flat plate toward the second member and has a tip that contacts an upper surface of the second member.

[0014] In the above configuration, the fourth member comprises a first flat plate to which vibrations of the subject's vital signs are transmitted from above, and a protrusion that protrudes from the first flat plate toward the second member and has a tip that contacts the upper surface of the second member, and the area where the protrusion contacts the upper surface of the second member includes the center of the second member in a planar view, and the area where the protrusion contacts the upper surface of the second member is less than or equal to 1 / 2 of the area of ​​the second member in a planar view.

[0015] In the above configuration, the third member may include a second flat plate provided below the first member and having a size equal to or larger than the first member in a plan view.

[0016] In the above configuration, the third member is larger than the first member, the fourth member is larger than the second member, and in a plan view, in a region surrounding the first member and the second member, 3 The member and the 4 The member may be configured to face each other with a gap therebetween.

[0017] In the above configuration, the first member and the second member may be arranged so that the second member overlaps a part of the human body to which the weight of the subject is applied. The present invention is a detection device comprising a housing having a space, a vibrating membrane provided inside the housing to divide the space in two, separating a first space from a second space, a bag-shaped first member filled with gas, a first tube connected at one end to the first space and connected at the other end to the first member, a bag-shaped second member filled with gas, a second tube connected at one end to the second space and connected at the other end to the second member, and a detector provided on the vibrating membrane for detecting the difference between the gas pressure in the first member and the gas pressure in the second member. Effect of the Invention

[0018] According to the present invention, it is possible to improve the detection accuracy. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram illustrating a vibration detection unit and a differential pressure sensor according to the first embodiment. [Diagram 2] FIG. 2(a) is a plan view of a vibration detection section in the first embodiment, and FIG. 2(b) and FIG. 2(c) are AA and BB cross-sectional views of FIG. 2(a), respectively. [Diagram 3] FIG. 3 is a diagram illustrating an example in which the vibration detection unit according to the first embodiment is disposed on a seat. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA of FIG. [Diagram 5] FIG. 5 is a block diagram illustrating the detection device according to the first embodiment. [Figure 6] FIG. 6 is a diagram showing a model in the simulation. [Figure 7] FIG. 7 is a diagram showing the volume reduction rates of the spaces 11 and 13 in the point pressing and area pressing in the simulation. [Figure 8] FIG. 8(a) is a cross-sectional view showing the arrangement of the spot pressing experimental apparatus in Experiment 1, and FIGS. 8(b) to 8(d) are plan views. [Figure 9] FIG. 9 is a cross-sectional view showing the arrangement of the surface pressing experimental device in Experiment 1. [Figure 10] FIG. 10 is a diagram showing the output value of the differential pressure sensor versus the position of the point pressing jig in Experiment 1. In FIG. [Figure 11] 11(a) to 11(c) are diagrams showing the S / N ratios in Experiment 2. [Figure 12]FIG. 12 is a diagram showing the output value of the differential pressure sensor versus the position of the point pressing jig in Experiments 1 and 2. [Figure 13] 13(a) to 13(c) are cross-sectional views of the vibration detection device showing examples of the transmission member in the first embodiment. [Figure 14] 14(a) to 14(f) are plan views showing examples of the axis in the first embodiment. [Figure 15] 15(a) to 15(f) are plan views showing examples of the transmission member and the pad in the first embodiment. [Figure 16] 16(a) to 16(f) are plan views showing examples of the arrangement of the support members in the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, the embodiments will be described with reference to the drawings. EXAMPLES

[0021] FIG. 1 is a schematic diagram showing a vibration detection unit and a differential pressure sensor in the first embodiment. As shown in FIG. 1, the vibration detection unit 10 includes a pad 12 (second member) and a pad 14 (first member). The pad 12 overlaps the pad 14, and vibration is transmitted between the pads 14 and 12. The pads 12 and 14 do not need to be in contact with each other as long as they are connected so that vibration can be transmitted. The pads 12 and 14 are bag-shaped members having spaces 11 and 13 filled with a gas such as air inside, and are made of a flexible resin or the like. The differential pressure sensor 20 includes a housing 22, a vibration membrane 24, and a piezoelectric element 25. The housing 22 is a rigid body, and spaces 21 and 23 are provided within the housing 22. The shapes and sizes of the spaces 21 and 23 are, for example, almost the same.

[0022] Here, the pads 12 and 14 are described as being flexible, but may have the following hardness. Here, the material of the pads 12 and 14 is, for example, polyethylene. The width of the pads 12 and 14 is, for example, 40 mm. That is, in the differential pressure sensor 20, the vibration transmitted to the pads 12 and 14 is detected by applying pressure to the piezoelectric element 25. The change in pressure in the spaces 11 and 13 due to the vibration transmitted to the pads 12 and 14 is transmitted to the change in pressure in the spaces 21 and 23, and as a result, the vibration membrane 24 is deformed. The piezoelectric element 25 detects the pressure due to the deformation of the vibration membrane 24. Therefore, the material of the pads 12 and 14 may be any material as long as the vibration transmitted to the pads 12 and 14 becomes the change in pressure in the spaces 11 and 13 and the piezoelectric element 25 can detect the vibration. For example, the pads 12 and 14 may be a somewhat hard material such as polycarbonate.

[0023] The shape of the housing 22 is, for example, a cylinder or box, and the housing 22 is mainly made of metal or resin. The housing 22 in FIG. 1 is, for example, a cylindrical shape consisting of a circular upper surface, a circular lower surface, and a side surface connecting the two surfaces. The outer shape of the pads 12 and 14 is a thin rectangular parallelepiped, for example, a small air mat or cushion, or a circular or elliptical shape like edible pie dough in a plan view, and the pads 12 and 14 have a bag-like shape with a hollow structure. The spaces 11 and 13 are kept at a pressure that is not crushed by the subject's weight. In FIG. 1, the lower surface of the pad 12 and the upper surface of the pad 14 are in contact with each other. When the subject's weight is applied, the pads 12 and 14 are deformed, and the area of ​​the contact surface between the pads 12 and 14 increases.

[0024] The vibration membrane 24 is provided to separate the spaces 21 and 23. That is, the lower surface of the inner wall that defines the space 21 is the upper surface of the vibration membrane 24, and the upper surface of the inner wall that defines the space 23 is the lower surface of the vibration membrane 24. The inner wall corresponding to the side wall of the housing 22 is provided with a protruding portion 22a that protrudes inward over the entire circumference. The periphery of the vibration membrane 24 is joined to the upper surface of the protruding portion 22a. The entire periphery of the vibration membrane 24 is fixed to the protruding portion 22a. The vibration membrane 24 may be provided on the lower surface of the protruding portion 22a. In addition, the side wall of the housing 22 is provided with connecting pipes corresponding to the spaces 21 and 23. These pipes are referred to as connecting portions 28 and 29 here. The connecting portions 28 and 29 are provided to connect the tubes 26 and 27. Thus, the space 21 is connected to the space 11 in the pad 12 via the connecting portion 28 and the tube 26. Space 23 is connected to space 13 in pad 14 via connection part 29 and tube 27. Spaces 21 and 23 are filled with a gas such as air or a fluid such as liquid. A piezoelectric element 25 is provided on the upper surface of vibrating membrane 24. Vibrating membrane 24 temporarily receives vibrations (e.g., pressure vibrations) from pads 12 and 14 and transmits them to piezoelectric element 25, so that piezoelectric element 25 is provided so as not to overlap protruding part 22a.

[0025] 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 the spaces 11 and 13 changes. The change in the gas pressure is transmitted to the spaces 21 and 23. Since the sensor is a differential pressure type, when the vibrations applied to the pads 12 and 14 have the same phase and amplitude, the vibrating membrane 24 hardly vibrates. Vibrations corresponding to the difference between the vibrations applied to the pads 12 and 14 are transmitted to the vibrating membrane 24. The piezoelectric element 25 detects the vibration of the vibrating membrane 24 (e.g., pressure vibration) and outputs a detection signal to the signal processing device 30 (e.g., a circuit) as a detector for detecting the pressure difference between the spaces 21 and 23. In addition to a piezoelectric sensor such as a piezoelectric element, a capacitance sensor, a piezoresistance sensor, a differential transformer, or the like may be used. In this way, the differential pressure sensor 20 detects the difference between the gas pressure in the pad 12 (ie, the pressure of the gas filling the space 11) and the gas pressure in the pad 14 (ie, the pressure of the gas filling the space 13).

[0026] FIG. 2(a) is a plan view of the vibration detection unit in the first embodiment, and FIG. 2(b) and FIG. 2(c) are a cross-sectional view taken along the line AA and a cross-sectional view taken along the line BB of FIG. 2(a), respectively. The overlapping direction of the pads 12 and 14 is the Z direction, and the extension directions of the sides of the pads 12 and 14 are the X direction and the Y direction. As shown in FIG. 2(a) to FIG. 2(c), the vibration detection unit 10 described in FIG. 1 includes the pads 12 (second member), 14 (first member), the transmission member 16 (fourth member), 18 (third member), and the support member 15. The pads 12 and 14 are overlapped and in contact with each other, and transmit vibration to each other. The transmission member 16 includes a flat plate 16a (first flat plate) and a shaft center 16b, and the transmission member 18 includes a flat plate 18a (second flat plate) and a shaft center 18b. The transmission members 16 and 18 are members that transmit vibration to the upper surface of the pad 12 and the lower surface of the pad 14, and are made of a material harder than the pads 12 and 14. The material used for the transmission members 16 and 18 is, for example, polyvinyl chloride. The flat plate 16a and the shaft center 16b may be separate members, and are integrally molded from the same material here. The flat plate 18a and the shaft center 18b may be separate members, and are integrally molded from the same material here. The areas between the flat plates 16a and 18a other than the pads 12, 14, the support member 15, and the shaft centers 16b and 18b are voids (for example, air). Also, the support member 15 may not be provided, and the flat plates 16a and 18a may be smaller than the pads 12 and 14.

[0027] The lower surface of the shaft center 16b contacts the upper surface of the pad 12, and the upper surface of the shaft center 18b contacts the lower surface of the pad 14. In a plan view, the shaft centers 16b and 18b are provided so as to overlap with the centers 12a and 14a of the pads 12 and 14. The support member 15 is provided so as to surround the pads 12 and 14, and supports the transmission members 16 and 18. The planar shape of the transmission members 16 and 18 is, for example, rectangular, and the support member 15 is provided, for example, at the four corners. The support member 15 is a member that supports the transmission members 16 and 18, and is made of a material harder than the pads 12 and 14. The support member 15 prevents a large force from being applied to the transmission member 16 or 18, which would destroy the pad 12 or 14, from being applied to the pads 12 and 14. The support member 15 may be circular in a plan view, and may support the transmission members 16 and 18 at three or more points in a plan view.

[0028] The preferred ranges of the dimensions of each member are described below. Pads 12 and 14 W2ax and W2bx: 10mm~150mm W2ay and W2by: 10mm~150mm H2a and H2b: 3mm to 20mm Thickness H3: 0.5mm~2mm Flat plate 16a W1ax: 3mm~150mm Way: 3mm~150mm H1a: 0.5mm~5mm Flat plate 18a W1bx:10mm~150mm W1by: 10mm~150mm H1b: 3mm~5mm Axles 16b and 18b W3ax and W3bx: 3mm~75mm W3ay and W3by: 3mm~75mm H3a and H3b: 0.5mm to 20mm Support member 15 W4x: 3mm~30mm W4y: 3mm~30mm Height: 7mm~80mm

[0029] The preferred range of the elastic modulus of each member is described below. Pads 12 and 14 Elasticity: 0.1Mpa~2000MPa Transmission members 16, 18 and support member 15 Elastic modulus: 50Mpa~4000MPa The elastic modulus of the transmission members 16, 18 and the support member 15 is preferably greater than the elastic modulus of the pads 12 and 14, more preferably 10 times or more.

[0030] FIG. 3 is a diagram showing an example in which the vibration detection unit 10 in the first embodiment is disposed on a seat. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3. When a subject 48 sits on the car seat 41, the right side is the +X direction side, the front side is the +Y direction side, and the upward direction is the +Z direction side. As shown in FIG. 3 and FIG. 4, a base 42, a seat cushion 44, and a seat back 46 are provided as the car seat 41 in a four-wheeled vehicle. The base 42 is, for example, a metal member. The thighs and buttocks of a subject 48 such as a driver shown in FIG. 4 come into contact with the seat cushion 44, and the neck, back, and waist of the subject 48 come into contact with the seat back 46. The vibration detection unit 10 shown in FIG. 1 and FIG. 4 is provided in the seat cushion 44. The seat cushion 44 is covered with a seat cloth 43. The seat cushion 44 is made of soft resin, for example, a foamed resin such as urethane. When the subject 48 sits in the car seat 41, the right buttock 48a of the subject 48 is positioned so as to overlap the vibration detection unit 10. Vibrations of the subject 48's vital signs and the like are transmitted to the vibration detection unit 10 via the seat cushion 44. The vibration detection unit 10 may be arranged so as to overlap the left buttock 48b, or so as to overlap the thigh. The vibration detection unit 10 may be arranged on the seat back 46 so as to overlap the neck, back or waist. The vibration detection unit 10 may be provided on a bicycle saddle, a desk chair, a bed, a mattress, a bracelet, and the like.

[0031] Fig. 5 is a block diagram showing the detection device in the first embodiment. As shown in Fig. 5, the detection device 100 includes a vibration detection unit 10 and a sensor unit 31. The differential pressure sensor 20 outputs a detection signal to a circuit component 35. The circuit component 35 includes, for example, a preamplifier (analog amplifier) ​​and amplifies the detection signal. A printed circuit board is provided in 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. The preamplifier may be prepared as one chip or one package and provided on the front or back surface of the vibration membrane 24.

[0032] The 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 unit 34, a memory 36, and an output unit 38. The amplifier 32 amplifies the output signal of the circuit component 35. The gain of the amplifier 32 is variable. The processing unit 34 is a processor such as a CPU (Central Processing Unit), which converts the amplified signal into analog-to-digital (AD) data, digitally processes the converted digital signal, and calculates (or computes) vital information such as respiration and pulse waves. The memory 36 is a volatile or non-volatile memory, and stores the program 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. The vital information is output using, for example, wireless communication or wired communication.

[0033] [simulation] As Comparative Example 1, pads 12 and 14 were embedded in a cushion member. The upper surface of the cushion member was divided into a point pressing case and an area pressing case, and the air reduction rate in the pads 12 and 14 was simulated two-dimensionally using ANSYS. FIG. 6 is a diagram showing a model in the simulation. The pads 12 and 14 were arranged in the cushion member 50 as shown in FIG. 6. It was assumed that the pads were symmetrical about a line 64, and the pads were symmetrical about the line 64. In the point pressing case, an area 60 of the upper surface of the cushion member 50 was pressed with a constant force F60. In the area pressing case, an area 62 of the upper surface of the cushion member 50 was pressed with a constant force F62.

[0034] The simulation conditions are as follows. Since this is a two-dimensional simulation, there is no depth dimension. Width of cushion member 50 W11: 84mm Height of cushion member 50 H11: 42mm Width of pads 12 and 14 W12: 20mm Total height of pads 12 and 14 H12: 10.5mm Thickness of pads 12 and 14 H13: 1.5mm Height of spaces 11 and 13 H14: 3mm Width of area 60 W60: 3mm Width of area 62 W62: 64mm Point pressing force F60: 4N Face pressing force F62: 130N Material of cushion member 50: urethane foam Material of pads 12, 14: polyethylene Spaces 11 and 13: Air The height H12 is the height from the lower surface of pad 14 to the upper surface of pad 12 when pads 12 and 14 are overlapped.

[0035] Here, a brief explanation will be given on point pressing and surface pressing. Surface pressing uses a plate-like member with a width equal to or greater than the width of the pads 12 and 14, and point pressing uses a member such as a rectangular prism with a width equal to or less than 25% of the pad width, and pads 12 and 14 are pressed. Even if the width of the member pressing pads 12 and 14 is equal to or greater than 25% of the width of the pads 12 and 14, it may be defined as point pressing as long as it provides substantially the same effect as when the width of the member pressing pads 12 and 14 is equal to or less than 25% of the width of the pads 12 and 14. The area of ​​the spaces 11 and 13 before the forces F60 and F62 are applied to the regions 60 and 62 is S0, and the area of ​​the spaces 11 and 13 when the forces F60 and F62 are applied to the regions 60 and 62 is S1. In this case, the volume reduction rate is (S0-S1) / S1 [%]. Note that the reduction rate of the area is taken as the volume reduction rate for the two-dimensional simulation.

[0036] The vibration source of the vibration of the vital signs, etc. is a part of the subject's body (e.g., a part of the buttocks). Therefore, point pressure corresponds to the vibration of the vital signs, etc. Disturbance vibration such as drive noise is transmitted to the entire cushion member 50. Therefore, surface pressure corresponds to disturbance vibration such as drive noise.

[0037] FIG. 7 is a diagram showing the volume reduction rates 11a and 13a of the spaces 11 and 13 in the case of point pressing and surface pressing, respectively, as a result of a simulation. As shown in FIG. 7, in the case of point pressing, the volume reduction rate 13a of the lower space 13 is smaller than the volume reduction rate 11a of the upper space 11. On the other hand, in the case of surface pressing, the volume reduction rates 11a and 13a of the lower space 13 and the upper space 11 are almost the same. In this way, the volume reduction rate due to surface pressing vibration, which corresponds to disturbance vibration, is almost the same in the spaces 11 and 13. As a result, disturbance vibration, for example, large vibration such as drive noise, is canceled in the differential pressure sensor 20. On the other hand, the volume reduction rate 11a of the space 11 due to point pressing vibration, which corresponds to vital vibration, is larger than the volume reduction rate 13a of the space 13. In other words, the upper pad 12 can receive the vibration of the point pressing more than twice as much as the lower pad 14. As a result, when vibrations of vital signs or the like are transmitted to the pad 12, the difference in pressure between the spaces 21 and 23 (i.e., the spaces 11 and 13) becomes large in the differential pressure sensor 20. For this reason, the vibrations of vital signs or the like are easily detected by the differential pressure sensor 20.

[0038] [Experiment 1] In Comparative Example 1 in which pads 12 and 14 are embedded in a cushion member 50, point-pressing vibration and surface-pressing vibration are applied to the upper surface of the cushion member 50, and the detection signal of the differential pressure sensor 20 is measured. FIG. 8(a) is a cross-sectional view showing the arrangement and structure of the point-pressing experimental device in Experiment 1, and FIG. 8(b) to FIG. 8(d) are plan views. As shown in FIG. 8(a), a cushion member 50 is placed on a rigid base 51. Pads 12 and 14 are embedded in the cushion member 50. A metal plate 52 is placed on the upper surface of the cushion member 50. A metal ring 57 is placed on the metal plate 52, and a vibrator 54, which is a speaker, is placed on top of the metal ring 57. A vibration unit 55 that generates vibrations is provided in the vibrator 54, and a weight 56 ​​with a mass of 1 kg is placed on the vibrator 54. A point-pressing jig 58 is in contact with the lower surface of the vibration unit 55, and this point-pressing jig 58 is in contact with the upper surface of the cushion member 50 via the metal ring 57 and an opening 59 in the metal plate 52. Fig. 8(b) is a plan view of metal plate 52, in which a circular opening 59 is formed. Fig. 8(c) is a plan view of metal ring 57, in which metal ring 57 is cylindrical. As shown in Figs. 8(a) to 8(d), the centers C of vibrator 54, vibration section 55, point pressing jig 58, metal ring 57, and opening 59 are substantially aligned.

[0039] Fig. 9 is a cross-sectional view showing the arrangement of the surface pressing experimental apparatus. As shown in Fig. 9, in the surface pressing experimental apparatus, no opening is provided in metal plate 52, and vibrator 54 is placed directly on metal plate 52. A 1 kg weight is placed on vibrator 54. The rest of the configuration is the same as the point pressing experimental apparatus in Fig. 8(a), so a description will be omitted.

[0040] The experimental conditions are as follows. Cushion member 50 width W21: 300mm Height of cushion member 50 H21: 60mm Width of pads 12 and 14 W22 Pad A: 40mm x 40mm Pad B: 160mm x 40mm Height of pads 12 and 14 H22: 8mm Width of metal plate 52 W23: 300mm Width of point pressing jig 58 W24: 10mm Vibration of vibration part 55: 10Hz sine wave Material of cushion member 50: urethane foam Material of pads 12, 14: polyethylene Spaces 11 and 13: Air

[0041] Table 1 shows the output values ​​of the differential pressure sensor 20 when the centers of the small pad A and the large pad B are approximately aligned with the centers of the pressing jig 58 and the metal plate 52. [Table 1]

[0042] The output value mVpp of the differential pressure sensor 20 indicates the voltage difference from the positive peak to the negative peak. "Differential pressure" is the detection result of the differential pressure sensor 20. Pads A and B of different sizes were adopted, and measurements were taken with the point pressing vibrator 54 in Fig. 8(a) to Fig. 8(d) and the surface pressing vibrator 54 in Fig. 9, respectively. A weight 56 ​​of 1 kg is placed in both cases. "Space 11" is the detection result of the differential pressure sensor 20 based on the pressure in the space 11 (i.e., the space 21 in Fig. 1), and the space 23 is not connected to the space 13 (pad 14) and is open. In other words, the point pressing and surface pressing in Fig. 8(a) to Fig. 8(d) and Fig. 9 are adopted, the tube 27 is plugged, and the pressure of the pad 14 is maintained at the same pressure as the pad 12. The space 23 is not connected to the tube 27 and is open. Therefore, only the vibration applied to the pad 12 is applied to the differential pressure sensor 20. "Space 13" is the detection result of differential pressure sensor 20 based on the pressure in space 13 (i.e., space 23 in Figure 1), and space 21 is not connected to space 11 and is open. Similarly, the point pressing and surface pressing of Figures 8(a) to 8(d) and Figure 9 are adopted, tube 26 is plugged, and the pressure of pad 12 is maintained at the same pressure as pad 14. Space 21 is not connected to tube 26 and is open. Therefore, only the vibration applied to pad 14 is applied to differential pressure sensor 20. "Space 11-Space 13" is the difference between the output value of "Space 11" and the output value of "Space 13".

[0043] As shown in Table 1, the values ​​in the "Differential Pressure" column for the output value of the differential pressure sensor 20 are almost the same as the values ​​in the "Space 11-Space 13" column. Point pressing produces a larger "differential pressure" output value of the differential pressure sensor 20 than surface pressing. For the larger sized pad B, the "differential pressure" for point pressing is smaller than for the smaller sized pad A. For the larger sized pad B, the "differential pressure" for surface pressing is larger than for pad A. In this way, point pressing can produce a larger output than surface pressing. Furthermore, the smaller the pad size, the greater the output value of the differential pressure sensor 20 for point pressing than for surface pressing.

[0044] From the above explanation, it was found that the point pressing mechanism can obtain a larger output from the differential pressure sensor 20 than the surface pressing mechanism. So, an experiment was conducted to see what happens when the position of the transmission member 16, which is the point pressing mechanism, is shifted. The position of the center C of the point pressing jig 58 shown in Figures 8(a) to 8(d) was shifted from the center (12a and 14a) of the pads (12 and 14), and the output value of the differential pressure sensor 20 in the point pressing was measured.

[0045] 10 is a diagram showing the output value of the differential pressure sensor 20 versus the position of the point pressing jig in Experiment 1. The position shown on the horizontal axis indicates the distance from the centers (12a and 14a) of the pads (12 and 14) to the center C of the point pressing jig 58. When the position is 0 mm, the centers (12a and 14a) of the pads (12 and 14) and the center C of the point pressing jig 58 coincide with each other. When the position is 20 mm for pad A, and when the position is 80 mm for pad B, they coincide with the edges of the pads (12 and 14).

[0046] As shown in Figure 10, when the position is 0 mm, the output value of the smaller pad A is larger than that of pad B. This is consistent with the results in Table 1. For pad A, the output value decreases rapidly as the position shifts, and when the position is 20 mm, the output value is nearly 0 mVpp. For pad B, which is larger, the output value when the position is 40 mm or less is smaller than the output value of pad A at 0 mm, but it remains almost the same regardless of position. When the position is greater than 40 mm, the output value gradually decreases, and when the position is 80 mm, the output value is nearly 0 mVpp.

[0047] The results of Experiment 1 are summarized in Table 1. 1. As the planar shape of the pad increases, the output value of point pressing decreases and the output value of area pressing increases. 2. Assuming that point pressure corresponds to vital vibration components and surface pressure corresponds to external vibration, the smaller the planar shape of the pad, the better. 3. As shown in Figure 10, by placing the touch point at the center of the pad, a large output value can be obtained. 4. If the flat shape of the pad is large, the output value is small when the center is pressed, but the output value does not change much even if the pressing position is shifted from the center. In this way, the smaller the pad, the higher the detection accuracy of vibrations such as vital signs, but the tolerance for positional misalignment is narrower. Since the area of ​​the vibration source of the subject's vital signs is small, the detection accuracy is low unless the vibration source of the subject is centered on the pad.

[0048] The following will be explained in more detail. In other words, to detect vibrations of vital signs, etc., the position of the blood vessels of the human body (for example, buttocks) must coincide with the center of the pad 12, and a point pressing mechanism must be adopted to coincide with the center of the point pressing, thereby maximizing the rate of change in the volume of the pad 12 and maximizing the output of the sensor (here, a differential pressure sensor). However, the human body is, for example, a driver, and the position at which the driver sits on the seat changes. Therefore, it is quite difficult to coincide the position of the blood vessels of the driver with the center of the pad 12. On the other hand, the above-mentioned problem is solved by adopting the configuration of Figures 2(a) to 2(c). Looking at Figures 2(a) to 2(c), the upper pad 12 and the lower pad 14 are provided with transmission members 16 and 18, respectively. Specifically, a shaft center 16b is provided on the flat plate 16a, which is the transmission member 16. Explaining the above structure, the shaft center 16b is provided integrally with the flat plate 16a. This shaft center 16b presses the pad 12 at a point. In other words, as long as the center of the axis 16b and the center 12a of the pad 12 do not deviate significantly from each other, the output of the sensor can be large.

[0049] On the other hand, the misalignment of blood vessels when the driver sits on the seat is solved by making the size of the flat plate 16a larger than that of the pad 12. When a part of the buttocks of the human body abuts on the cushioning material on the flat plate 16a, the vibration of vital signs from the blood vessels is transmitted from above to the flat plate 16a. As a result, the vibration is transmitted from the flat plate 16a to the axis 16b and from the axis 16b to the upper surface of the pad 12. The center of the axis 16b coincides with the center of the pad 12, so that the output of the sensor can be large. The positional relationship and effect of the lower flat plate 18a, axis 18b, and pad 14 are also the same, so the explanation will be omitted. The axis 16b and 18b do not have to be integral with the flat plates 16a and 18a and made of the same material. Also, a certain degree of misalignment between the centers of the axis 16b and 18b and the centers 12a and 14a of the pads 12 and 14 is allowed.

[0050] The vibration of vital signs, etc. is small compared to disturbance vibrations such as drive noise. The vibration is transmitted to the pad 12 via the upper flat plate 16a and the axis 16b. It can be considered that the vibration of vital signs, etc. is hardly transmitted from the lower flat plate 18a to the pad 14. On the other hand, the disturbance vibration of drive noise, etc. is considerably large compared to the vibration of vital signs, etc. For this reason, the disturbance vibration is transmitted to the upper flat plate 16a and the lower flat plate 18a at almost the same level. Therefore, in the differential pressure sensor 20, the disturbance vibration is canceled and the vibration of vital signs, etc. can be extracted. As shown in Figs. 1 to 2(c), the first embodiment is composed of two stacked pads 12 and 14 and one differential pressure sensor 20. However, in Fig. 2(b), the pad may be one. In this case, the flat plates 16a and 18a are provided above and below this one pad, and the effect is also great even if the axis is provided between at least one of the flat plates and the pad. In that case, the sensor does not have to be a differential pressure type.

[0051] In order to make the vibration amplitude of the gas pressure in the spaces 11 and 13 caused by the disturbance vibration approximately the same, it is preferable that the planar shapes and volumes of the pads 12 and 14 are approximately the same. It is preferable that the planar shapes of the transmission members 16 and 18 (shaft centers 16b and 18b) are approximately the same.

[0052] [Experiment 2] The size of the planar shape of the axes 16b and 18b of the transmission members 16 and 18 was changed to measure the S / N (Signal / Noise) ratio of the vital sign vibration and the disturbance vibration. The detection device of Example 1 was installed on a car seat 41 as shown in Figs. 3 and 4. A subject 48 was seated on the car seat 41. As a result, the vital sign vibration was transmitted from the subject's buttocks to the detection device. A vibrator was installed under the car seat 41 to provide disturbance vibration. The vibrator applied a sine wave vibration with a frequency of 20 Hz and an amplitude of 2000 mV to the car seat 41.

[0053] Other experimental conditions are as follows (see Figures 2(a) to 2(c) for each dimension). Cushion member 50 width W21: 300mm Height of cushion member 50 H21: 60mm Pad 12 Plane shape: square Width W2a: W2ax = W2ay = 40mm Height H2a: 8mm Pad 14 Plane shape: square Width W2b: W2bx = W2by = 40mm Height H2b: 8mm Flat plate 16a Plane shape: square Width W1a:W1ax = Width W1ay = 90mm Height H1a: 2mm Flat plate 18a Plane shape: square Width W1b: W1bx = W1by = 110mm Height H1b: 2mm Axial center 16b Planar shape:Circular Width W3a:W3ax=W3ay Height H3a: 2mm Axial center 18b Planar shape:Circular Width W3b:W3bx=W3by Height H3b: 2mm Support member 15 Plane shape: square Width W4: W4x = W4y = 15mm Height: H2a+H2b+H3a+H3b=20mm Material of cushion member 50: urethane foam Material of pads 12, 14: polyethylene Material of transmission members 16, 18: PVC Material of the support member 15: PVC Spaces 11 and 13: Air

[0054] The S / N ratio was measured by changing the width (diameter) of the shaft centers (16b and 18b). The centers of the shaft centers (16b and 18b) were aligned with the centers (12a and 14a) of the pads (12 and 14). Figures 11(a) to 11(c) are diagrams showing the S / N ratio in experiment 2. The S / N ratio is expressed in dB, and a larger S / N ratio (closer to 0) indicates a larger vital vibration in response to external vibration and higher detection accuracy. As shown in Figures 14(a) to 14(d) described later, the shaft center is assumed to be a circular cylinder in plan view, but it may be a polygon other than a circle.

[0055] In FIG. 11(a), the widths (W3a and W3b) of the shaft centers (16b and 18b) are the same. The widths (W2a and W2b) of the pads (12 and 14) in a plan view are 40 mm × 40 mm, and when W3a = W3b = 50 mm, the shaft centers (16b and 18b) are larger than the pads (12 and 14). In this case, the S / N ratio is approximately -50 dB, which is the lowest. When the width of the shaft center, which is smaller than the pad width, is 20 mm or 30 mm, the S / N ratio increases, but when it is 10 mm, the S / N ratio becomes slightly worse.

[0056] In FIG. 11(b), the width W3a of the axis 16b is set smaller than the width W3b of the axis 18b. When W3a is 10 mm and W3b is 50 mm, the S / N ratio is the largest. When W3a is 30 mm, the S / N ratio is small. Even when W3b is 30 mm, the S / N ratio is small. In FIG. 11(c), the width W3a of the axis 16b is set larger than the width W3b of the axis 18b. When W3a is 50 mm and W3b is 10 mm, the S / N ratio is about -50 dB, which is the same as when W3a and W3b are 50 mm. When W3b is 30 mm, the S / N ratio is large. Even when W3a is 30 mm, the S / N ratio is large. In short, as shown in FIG. 11(b), when W3a=10 mm and W3b=50 mm, the S / N ratio is the largest, and it can be said that this is the combination that makes it easy to detect vital sign vibrations. On the other hand, as shown in Figure 11(c), the S / N ratio is smallest when W3a = 50 mm and W3b = 10 mm, making this combination difficult to measure vital signs.

[0057] In experiment 2, the area where the axis 16b is in contact with the upper surface of the pad 12 is calculated. The area of ​​the pad 12 in plan view is 40 mm × 40 mm = 1600 mm 2 When the width W3a is 50 mm, the upper surface of the pad 12 other than the four corners of the pad 12 is in contact with the axis 16b. In other words, the area of ​​the pad 12 in a plan view and the area where the axis 16b is in contact with the upper surface of the pad 12 are approximately the same. When the width W3a is 10 mm, 20 mm, and 30 mm, the area where the axis 16b is in contact with the upper surface of the pad 12 is 79 mm 2 , 314mm 2 , 707mm 2 Both of these are smaller than the area of ​​the pad 12 in a plan view.

[0058] 11(a) to 11(c), when the width W3a of the axis 16b is 10 mm, 20 mm, or 30 mm, the S / N ratio is larger than when the width W3a of the axis 16b is 50 mm. That is, when the vibration of the subject's vital signs is transmitted from above, the S / N ratio can be increased by making the area where the axis 16b contacts the upper surface of the pad 12 smaller than the area of ​​the pad 12 in a plan view. The area where the axis 16b contacts the upper surface of the pad 12 is preferably 1 / 2 or less, more preferably 1 / 3 or less, and even more preferably 1 / 4 or less of the area of ​​the pad 12 in a plan view.

[0059] 11(a) when width W3a is 10 mm and 30 mm and FIG. 11(b) when width W3a is 10 mm and 30 mm, the S / N ratio can be increased by making the area where axis 18b contacts the underside of pad 14 larger than the area where axis 16b contacts pad 14. The area where axis 18b contacts the underside of pad 14 is preferably at least twice the area where axis 16b contacts pad 14, and more preferably at least four times.

[0060] Using the same experimental apparatus for point pressing as that shown in Figs. 8(a) to 8(d) of Experiment 1, the detection apparatus of Example 1 was placed in the cushion member 50, and the center C of the point pressing jig 58 was shifted from the centers 12a and 14a of the pads 12 and 14, and the output value of the differential pressure sensor 20 in point pressing was measured. Fig. 12 is a diagram showing the output value of the differential pressure sensor 20 relative to the position of the point pressing jig in Experiments 1 and 2. Pad A in Experiment 1 has the same data as Pad A in Fig. 10 of Experiment 1. Experiment 2 is the measurement result when the widths W3a and W3b of the shaft centers 16b and 18b are 10 mm and 30 mm, respectively. The dots indicate measurement points, and the lines are straight lines connecting the dots.

[0061] As shown in Fig. 12, in Experiment 2, pad A in Experiment 1 and pads 12 and 14 are the same size, but the output value does not decrease even if the pressing position is shifted from the center 12a and 14a. In this way, the tolerance for the position of the vibration source of the subject's vital signs, etc. is larger in Experiment 2 than in Pad A in Experiment 1. In this way, in Example 1, by providing transmission members 16 and 18, it is possible to transmit vibration to the center of pad 12 where the output value of differential pressure sensor 20 is maximum, and also to prevent excessive sinking of vibration detection unit 10 into the cushion member, so that the S / N ratio of the vibration of the vital signs, etc. can be improved even if the position of the vibration source of the subject's vital signs, etc. changes.

[0062] 13(a) to 13(c) are cross-sectional views of a vibration detection device showing examples of a transmission member in the first embodiment. As shown in FIG. 13(a), the lower transmission member 18 may be formed of a flat plate and may not include the axis. As shown in FIG. 13(b), the width W3b of the lower axis 18b may be larger than the width W3a of the upper axis 16b. As shown in FIG. 13(c), the area where the axis (16b and 18b) contacts the pads (12 and 14) may be smaller than the area where the axis 16b and 18b contact the flat plates 16a and 18a. With this structure, the vibration of the flat plate can be efficiently converged to the axis.

[0063] From the results of experiment 2 shown in Fig. 11(a) to Fig. 11(c), it is preferable that the transmission member 18 does not include the axis 18b as shown in Fig. 13(a), or that the width W3b is greater than the width W3a as shown in Fig. 13(b). As shown in Fig. 13(c), the axes 16b and 18b may be frustum-shaped. This allows the vibration applied to the flat plates 16a and 18a to be efficiently transmitted to the pads 12 and 14.

[0064] The transmission member 16 has a flat plate 16a on the pad 12. This allows the vibrations of the subject's vital signs and the like to be received by the flat plate 16a. A cushioning member such as a foamed resin is provided between the flat plate 16a and the subject. The transmission member 16 has a shaft 16b (protruding portion) that protrudes from the flat plate 16a toward the pad 12 and whose tip contacts the pad 12. This allows the vibrations received by the flat plate 16a to be transmitted to the pad 12. In addition, since the area where the transmission member 16 contacts the pad 12 can be reduced, the S / N ratio can be improved as shown in Figures 11(a) to 11(c). At this time, it is not necessary to align the subject's buttocks so that they overlap the center 12a of the pad 12. The shaft 16b is provided so as to be approximately aligned with the center 12a of the pad 12. Therefore, regardless of which part of the flat plate 16a the subject's buttocks are in contact with, the presence of the shaft 16b allows the vibrations of the vital signs and the like to be transmitted to the center 12a of the pad 12. This improves the accuracy of vibration detection for vital signs, etc. The flat plate and the protruding portion of the transmission member 16 may be formed integrally, or may be separate members.

[0065] The transmission member 18 has a flat plate 18a under the pad 14. This allows disturbance vibrations such as drive noise to be transmitted to the pads 14 and 12. In addition, it is possible to prevent the vibration detection unit 10 from sinking into the cushion member or the like. The transmission member 18 may have an axis 18b (protruding portion) that protrudes from the flat plate 18a toward the pad 14 and whose tip contacts the pad 14. Note that the flat plates 16a and 18a only need to have flat plate-like regions that overlap with the pads 12 and 14 and regions that surround the pads 12 and 14 in a plan view. For example, the peripheral portions of the flat plates 16a and 18a may be curved upward or downward.

[0066] In a plan view, in the region surrounding pads 12 and 14, transmission members 16 and 18 preferably face each other with a gap such as air therebetween. This allows vibrations received by transmission members 16 and 18 to be transmitted to pads 12 and 14 only via transmission members 16 and 18. This improves the S / N ratio of vibrations such as those of vital signs.

[0067] 14(a) to 14(f) are plan views showing examples of the shaft cores in the first embodiment. As shown in FIG. 14(a), the planar shape of the shaft cores 16b and 18b may be a quadrangle such as a square or a rectangle, or a polygon other than a quadrangle, instead of a circle as shown in FIG. 2(a). As shown in FIG. 14(b), the planar shape of the shaft cores 16b and 18b may have a curved outer periphery such as an ellipse, an oval, or an egg shape. When the shaft cores 16b and 18b are polygonal, stress may be concentrated and applied to the pads 12 and 14 at the apex of the outer periphery. When the outer periphery of the planar shape of the shaft cores 16b and 18b is curved, the concentration of stress applied to the pads 12 and 14 can be suppressed.

[0068] Figures 14(c) and 14(d) correspond to the axes 16b and 18b in Figure 13(d). In Figure 14(c), the plane shapes of the axes 16b and 18b are elliptical, and in Figure 14(d), the plane shapes of the axes 16b and 18b are rectangular. Regions 16d and 18d are regions where the axes 16b and 18b contact the pads 12 and 14. As in Figures 14(a) to 14(d), the plane shapes of the axes 16b and 18b can be set appropriately. The three-dimensional shapes of the axes 16b and 18b may be columnar, such as a cylinder or a polygonal column, or may be frustum. The plane shapes and three-dimensional shapes of the axes 16b and 18b may be the same or different.

[0069] The regions where the shaft centers 16b and 18b contact the upper surface of the pad 12 and the lower surface of the pad 14, respectively, include the center 12a of the pad 12 in a plan view and the center 14a of the pad 14 in a plan view. This allows the vibration from the transmission member 16 to be efficiently transmitted to the pad 12, as shown in Figure 12 of Experiment 2. It is preferable that the centers of the regions where the shaft centers 16b and 18b contact the upper surface of the pad 12 and the lower surface of the pad 14, respectively, approximately coincide with the centers 12a and 14a.

[0070] As shown in Fig. 14(e), two shaft centers 16b and two shaft centers 18b are provided. The shaft centers 16b and 18b are provided approximately symmetrically with respect to the centers 12a and 14a of the pads 12 and 14, sandwiching the centers 12a and 14a. As a result, the centers of gravity of the shaft centers 16b and 18b approximately coincide with the centers 12a and 14a. Therefore, the vibration of the transmission members 16 and 18 can be efficiently transmitted to the pads 12 and 14.

[0071] As shown in Fig. 14(f), four shaft centers 16b and four shaft centers 18b are provided. The shaft centers 16b and 18b are provided approximately symmetrically with respect to the centers 12a and 14a of the pads 12 and 14 so as to surround the centers 12a and 14a of the pads 12 and 14. As a result, the centers of gravity of the shaft centers 16b and 18b approximately coincide with the centers 12a and 14a. Therefore, the vibration of the transmission members 16 and 18 can be efficiently transmitted to the pads 12 and 14. The number of shaft centers 16b and the number of shaft centers 18b may be the same or different.

[0072] 15(a) to 15(f) are plan views showing examples of the transmission member and pad in the first embodiment. As shown in FIG. 15(a), the planar shape of the transmission members 16 and 18 may be a square, not a rectangle as in FIG. 2(a). As shown in FIG. 15(b), the planar shape of the transmission members 16 and 18 may be a circle, an ellipse, an oval, or an egg, with a curved periphery. As shown in FIG. 15(c), the planar shape of the transmission members 16 and 18 may be a + shape, an X shape, or a star shape. For example, if the planar shape of the transmission members 16 and 18 is a + shape, the vibration of the vibration source of the subject's vital signs, etc. can be efficiently transmitted to the pads 12 and 14 even if the subject sits with his / her posture collapsed forward, the subject sits with his / her center of gravity on the seat back side, or the subject sits shifted to the right or left side. Furthermore, the volume of the cushion member 50 removed from the seat cushion 44 can be reduced, so that the strength of the seat cushion 44 can be ensured. The planar shapes and sizes of the transmission members 16 and 18 may be the same or different.

[0073] As shown in Fig. 15(d), the planar shape of the pads 12 and 14 may be substantially rectangular, or may be a polygon other than a square, instead of the substantially square shape shown in Fig. 2(a). As shown in Fig. 15(e), the planar shape of the pads 12 and 14 may be substantially circular. As shown in Fig. 15(f), the planar shape of the pads 12 and 14 may be substantially elliptical, oblong, or egg-shaped. In this way, the planar shape of the pads 12 and 14 may have a curved periphery. The planar shapes of the pads 12 and 14 may be the same or different.

[0074] 16(a) to 16(f) are plan views showing examples of the arrangement of the support members in the first embodiment. As shown in FIG. 16(a), two support members 15 are provided at each of the four corners of the transmission members 16 and 18. In this manner, a plurality of support members 15 may be provided at each of the four corners of the transmission members 16 and 18. As shown in FIG. 16(b), the support members 15 may be provided near the center of each of the four sides of the transmission members 16 and 18. A plurality of support members 15 may be provided near the center of each of the four sides of the transmission members 16 and 18. As shown in FIG. 16(c), the support members 15 are provided at both ends of one of the two opposing sides of the transmission members 16 and 18 and near the center of the other of the two sides.

[0075] As shown in Fig. 16(d), the support member 15 is provided along two opposing sides of the transmission members 16 and 18. As shown in Fig. 16(e), the support member 15 is provided in an area of ​​each of the two opposing sides of the transmission members 16 and 18 excluding both ends. As shown in Fig. 16(f), the support member 15 is provided along one of the two opposing sides of the transmission members 16 and 18, and is provided in the center of the other of the two sides.

[0076] By providing the support member 15 between the transmission members 16 and 18 and connecting the transmission members 16 and 18, the durability of the vibration detection unit 10 can be increased and damage to the vibration detection unit 10 can be suppressed even if the subject sits down and applies his / her weight to the vibration detection unit 10. By providing the support member 15 so as to surround the pads 12 and 14 in a plan view, the durability of the vibration detection unit 10 can be increased. If the support member 15 is provided so as to surround the pads 12 and 14 360°, the vibration of the transmission members 16 and 18 will be hindered. Therefore, it is preferable that the support member 15 is provided in a part surrounding the pads 12 and 14 in a plan view and not provided in a part. For example, it is preferable that the support member 15 is provided symmetrically with respect to the center of the pads 12 and 14.

[0077] The vibration of vital signs and the like is, for example, the vibration of breathing or pulse. The driving noise includes, for example, at least one of the wind of an air conditioner, the sound of an engine, the body movement of a human body, and road noise (noise from a road). Body movement refers to the movement of a driver while driving, such as driving operations. When a wheelchair or a mobile bed moves, a driving noise similar to that of a vehicle is generated, making it difficult to detect the vibration of the subject's vital signs and the like. Therefore, the first embodiment may be used to detect the vibration of vital signs and the like from a subject sitting in a seat such as a wheelchair, or the vibration of vital signs and the like from a subject lying on a mobile bed.

[0078] When the subject is seated in a seat, the buttocks are the most suitable vibration source for vital signs, etc. Therefore, as shown in Fig. 4, it is preferable that pads 12 and 14 are provided so as to overlap the body part on which weight is applied, such as the subject's buttocks (for example, right buttock 48a or left buttock 48b). Pads 12 and 14 may be provided so as to overlap the vibration source for vital signs, etc., such as the subject's thighs.

[0079] 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 are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0080] 10 Vibration detection unit 11, 13, 21, 23 space 12, 14 pads 12a, 14a center 15 Support member 16, 18 Transmission members 16a, 18a flat plate 16b, 18b axis center 20 Differential Pressure Sensor 22 Case 24 Diaphragm 25 Piezoelectric element

Claims

1. a bag-shaped first member filled with a gas; a bag-shaped second member connected onto the first member and filled with gas; A third member that transmits vibration to a lower surface of the first member; a fourth member that transmits vibration to an upper surface of the second member; a detector for detecting a difference between a gas pressure in the first member and a gas pressure in the second member; Equipped with A detection device in which the area where the fourth member is in contact with the upper surface of the second member is smaller than the area of ​​the second member in a plan view.

2. The detection device according to claim 1 , wherein the fourth member is larger than the second member in a plan view.

3. The detection device according to claim 1 or 2, wherein vibrations of the subject's vital signs are transmitted from above the fourth member.

4. Vibrations of the subject's vital signs are transmitted from above the fourth member, The detection device according to claim 1 , wherein an area of ​​the fourth member in contact with the second member is equal to or smaller than half an area of ​​the second member in a plan view.

5. 5. The detection device according to claim 3, wherein an area of ​​the third member in contact with the lower surface of the first member is equal to or larger than an area of ​​the fourth member in contact with the second member.

6. The detection device according to claim 3 , wherein a region where the fourth member is in contact with an upper surface of the second member includes a center of the second member in a plan view.

7. In a plan view, the third member is larger than the first member, and the fourth member is larger than the second member, 7. The detection device according to claim 1, further comprising a support member provided between the third member and the fourth member in a portion surrounding the first member and the second member in a planar view, the support member connecting the third member and the fourth member.

8. The detection device according to claim 1 , wherein the fourth member comprises a first flat plate and a protruding portion that protrudes from the first flat plate toward the second member and has a tip that contacts an upper surface of the second member.

9. the fourth member includes a first plate to which vibrations of the subject's vital signs are transmitted from above, and a protruding portion protruding from the first plate toward the second member and having a tip that contacts an upper surface of the second member; 8. The detection device according to claim 1, wherein a region where the protrusion contacts the upper surface of the second member includes a center of the second member in a planar view, and an area where the protrusion contacts the upper surface of the second member is less than or equal to 1 / 2 of an area of ​​the second member in a planar view.

10. The detection device according to claim 8 , wherein the third member includes a second flat plate provided below the first member and having a size equal to or larger than the first member in a plan view.

11. In a plan view, the third member is larger than the first member, and the fourth member is larger than the second member, The detection device according to claim 1 , wherein the third member and the fourth member face each other across a gap in a region surrounding the first member and the second member in a plan view.

12. The detection device according to claim 1 , wherein the first member and the second member are provided so as to overlap a part of the human body to which the subject applies weight on the second member.

13. A housing having a space; a vibration membrane provided inside the housing so as to divide the space into two, i.e., a first space and a second space; a bag-shaped first member filled with a gas; a first tube having one end connected to the first space and the other end connected to the first member; a bag-shaped second member filled with gas; a second tube connected to the second space at one end and to the second member at the other end; a detector provided on the vibration membrane for detecting a difference between a gas pressure in the first member and a gas pressure in the second member; A detection device comprising:

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