Biological information detection device

Abstract

The objective is to provide a biometric information detection device that can improve sensor sensitivity by providing a location that facilitates stress and strain in the piezoelectric sensor. [Solution] The biological information detection device comprises a first pressure sensor 10 as a linear first sensor that detects radial pressure applied from a living body, and thread members 38 as support parts that are repeatedly arranged along the longitudinal direction of the first sensor and support the first sensor.

Description

Technical Field

[0001] The disclosed technology relates to a biological information detection device.

Background Art

[0002] A piezoelectric substrate including a long conductor and a long first piezoelectric body spirally wound around the conductor in one direction is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the device described in Patent Document 1, when there is a support for supporting the device against stress from the human body and the support is a hard one such as a bed frame, there is a problem that the stress strain of the piezoelectric sensor becomes small and the sensor sensitivity becomes low.

[0005] In view of the above circumstances, the disclosed technology aims to provide a biological information detection device capable of improving sensor sensitivity by providing a portion where stress strain is likely to occur in the piezoelectric sensor.

Means for Solving the Problems

[0006] Means for solving the above problems include the following embodiments.

[0007] <1> A biological information detection device including a linear first sensor that detects pressure applied in the radial direction received from a living body, and a support portion that is repeatedly arranged along the longitudinal direction of the first sensor and supports the first sensor.

[0008] <2> The support portion is integrally formed with the substrate that supports the first sensor. <1> A biological information detection device as described above.

[0009] <3> The support portion is configured separately from the substrate that supports the first sensor. <1> A biological information detection device as described above.

[0010] <4> The system includes elastic members that alternately support the first sensor with the support portion. <1> A biological information detection device as described above.

[0011] <5> The support portion supports the first sensor via an elastic member. <1> A biological information detection device as described above.

[0012] <6> The first sensor includes a long conductor and a long, flat piezoelectric material made of an optically active helical chiral polymer wound around the outer circumference of the conductor, wherein polarization occurs in the radial direction with respect to axial stress. <1> A biological information detection device as described above.

[0013] <7> The aforementioned helical chiral polymer is polylactic acid. <6> A biological information detection device as described above.

[0014] <8> The first sensor has a piezoelectric constant d 14 This is a long organic piezoelectric material containing an organic piezoelectric material having the following properties: <6> A biological information detection device as described above.

[0015] <9> The first sensor is provided on the support that supports the living organism, <1> from <8> A biological information detection device as described in any one of the following.

[0016] <10> The support is a bed on which the living body lies, and the first sensor is positioned at least in the upper body region when the living body lies on the bed. <9> A biological information detection device as described above.

[0017] <11> The support is a bed on which the living organism sleeps, and the first sensor is arranged along the width direction of the bed. <9> A biological information detection device as described above.

[0018] <12> The biological information detection device according to <9>, comprising a resistive second sensor that detects the pressure received from the living body supported by the support.

[0019] <13> The biological information detection device according to <12>, wherein the first sensor and the second sensor are arranged parallel to each other.

[0020] <14> The biological information detection device according to <12>, wherein the first sensor and the second sensor are provided along the pressure receiving surface that receives pressure from the living body on the support, and the second sensor is installed on a base material that supports the first sensor.

Advantages of the Invention

[0021] According to the disclosed technology, the sensor sensitivity can be improved by increasing the stress strain generated in the piezoelectric sensor.

Brief Description of the Drawings

[0022] [Figure 1] It is an exploded perspective view of a bed device according to the first embodiment. [Figure 2A] It is a perspective view of a sensor unit of a biological information detection device according to the first embodiment as viewed from above. [Figure 2B] It is a cross-sectional view (cross-sectional view taken along line A-A of FIG. 2A) showing the layer structure of a sensor unit of a biological information detection device according to the first embodiment. [Figure 2C] It is a plan view of a modified example of a sensor unit of a biological information detection device according to the first embodiment as viewed from above. [Figure 3] It is a block diagram showing an example of the hardware configuration of a biological information detection device according to the first embodiment. [Figure 4] It is a block diagram showing an example of the functional configuration of a biological information detection device according to the first embodiment. [Figure 5] It is a front view showing an aspect of a first pressure sensor according to the first embodiment. [Figure 6] This is a cross-sectional view taken along the line V1-V1 in Figure 5 according to the first embodiment. [Figure 7] This figure shows an example of the detection result of the first pressure sensor when a modified version of the sensor unit of the biological information detection device according to the first embodiment is used. [Figure 8A] This is a top view of the sensor unit of the biological information detection device according to the second embodiment. [Figure 8B] This is a cross-sectional view (cross-sectional view along line AA in Figure 8A) showing the layer configuration of the sensor unit of the biological information detection device according to the second embodiment. [Figure 9] This is a block diagram showing an example of the hardware configuration of a biometric information detection device according to the second embodiment. [Figure 10A] This is a schematic plan view of a sensor unit according to the third embodiment. [Figure 10B] This is a schematic side cross-sectional view of a sensor unit according to the third embodiment. [Figure 11A] This is a schematic plan view of the sensor unit according to the fourth embodiment. [Figure 11B] This is a schematic side cross-sectional view of a sensor unit according to the fourth embodiment. [Figure 12A] This is a schematic plan view of the sensor unit according to the fifth embodiment. [Figure 12B] This is a schematic side cross-sectional view of a sensor unit according to the fifth embodiment. [Figure 13A] This is a schematic plan view of a sensor unit according to the sixth embodiment. [Figure 13B] This is a schematic side cross-sectional view of a sensor unit according to the sixth embodiment. [Figure 14A] This is a schematic plan view of the sensor unit according to the seventh embodiment. [Figure 14B] This is a schematic side cross-sectional view of a sensor unit according to the seventh embodiment. [Figure 15A] This is a schematic plan view of the sensor unit according to the eighth embodiment. [Figure 15B]This is a schematic side cross-sectional view of a sensor unit according to the eighth embodiment. [Modes for carrying out the invention]

[0023] [First Embodiment] Hereinafter, the bed device 100, which is a human body detection system according to this disclosure, and the biometric information detection device 50 provided in the bed device 100 will be described with reference to the drawings. In each drawing, identical or equivalent components and parts are given the same reference numerals. Also, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios. In this embodiment, the case in which the biometric information detection device 50 is applied to the bed device 100 will be described, but the biometric information detection device 50 can be applied to any object that receives pressure from a living body, not limited to bedding.

[0024] (Biometric information detection device) As shown in Figure 1, the bed device 100 of this embodiment comprises a bed 200 with legs and a biological information detection device 50. The bed 200 comprises a frame-shaped frame 210 installed on the floor surface, a floorboard 220 covering the central part of the frame 210, and a mattress 230 placed on the upper surface of the floorboard 220. The mattress 230, which serves as the pressurizing element, is a plate-shaped urethane foam covered with polyester fabric. The mattress 230 is placed on the floorboard 220 and the sensor unit 32, which will be described later, and a person lies on its upper surface. The bed 200 in this embodiment is an example of a support structure, and the sensor unit 32 is pressurized by the person lying on the mattress 230 via the mattress 230.

[0025] In this embodiment, the mattress 230 is made of polyurethane (urethane foam) in the area that receives pressure, but it is not limited to this and may be made of fiber or latex. Also, the area that receives pressure does not necessarily have to be the mattress 230 provided by the bed 200, but may be a sheet, a mat, or a futon. Here, the thickness of the mattress 230 is in the range of 0.005 to 50 mm, and the hardness of the mattress 230 is in the range of 50 to 200 N, preferably 100 to 200 N, and more preferably 110 to 170 N, when measured in accordance with Method A specified in JIS K6400-2.

[0026] Furthermore, according to Method A specified in JIS K6400-2, the hardness of the mattress 230 in this embodiment can be determined as follows. Specifically, the hardness of the mattress 230 is determined by placing the foam inside the mattress 230 flat, placing a circular pressure plate with a diameter of 200 mm on top, pressing it down to a distance of 75% of the original thickness of the foam, returning it to its original position, pressing it down again to a distance of 40% of the original thickness, and leaving it still for 30 seconds. The load value at this point is expressed as N (Newtons). As described above, the bed device 100 of this embodiment functions as a bed 200 with the frame 210, floorboard 220, and mattress 230, but by installing the sensor unit 32 between the floorboard 220 and the mattress 230, it becomes possible to detect a human body on the floor surface. Note that the installation of the sensor unit 32 is not limited to the case where it is installed between the floorboard 220 and the mattress 230, but the sensor unit 32 may also be installed on the upper surface of the mattress 230.

[0027] As shown in Figure 1, the biometric information detection device 50 comprises a sensor unit 32 and an information processing unit 40. The sensor unit 32 is positioned in the upper body area when a person lies on the bed 200. The sensor unit 32 is also installed between the mattress 230 and the bed base 220 of the bed 200, along the pressure-receiving surface that receives pressure from the person lying on the bed 200. When a person lies on the top surface of the mattress 230, the sensor unit 32 detects the pressure received from that person (see arrow P in Figure 2). As shown in Figure 1, the sensor unit 32 is positioned along the width of the bed 200. That is, the sensor unit 32 is installed in a direction intersecting with the sleeping person's body.

[0028] The sensor unit 32 is configured such that the first pressure sensor can detect the pressure applied from the direction of intersection of the reference surface 33 (see arrow P), with the protective sheet 37A (described later) as the reference surface 33 (see Figure 2B).

[0029] (Sensor unit configuration) Next, the configuration of the sensor unit 32 will be described. Figure 2A is a perspective view of the sensor unit 32 as seen from above. Figure 2B is a diagram showing the layer configuration of the sensor unit 32 based on the cross-sectional view of line AA shown in Figure 2A.

[0030] As shown in Figure 2A, the sensor unit 32 comprises protective sheets 37A, 37B, and 37C, a plurality of thread members 38, a first pressure sensor 10, and a coaxial cable 110. Protective sheet 37A is the part that is placed directly on the floor plate 220. As shown in Figure 2B, the plurality of thread members 38 are installed on top of protective sheet 37A. Protective sheet 37B is installed on top of protective sheet 37A and on each of the thread members 38 on the upper surface of protective sheet 37A. The first pressure sensor 10 is installed on top of protective sheet 37B. Protective sheet 37C is installed on top of protective sheet 37B and on the upper surface of protective sheet 37B, on top of the first pressure sensor 10. The coaxial cable 110 is electrically connected to the first pressure sensor 10. The components are bonded to each other using double-sided tape and adhesive. Furthermore, as shown in Figure 2A, in areas where the first pressure sensor 10 and protective sheet 37B are raised without following the thread member 38, spaces S are formed on both sides of the thread member 38. The protective sheet 37A is an example of a "base material". The thread member 38 is an example of a "support part". The sensor unit 32 may also be equipped with a support plate (not shown). The support plate is a member that allows tension to be transmitted by the first pressure sensor 10. The support plate is located in the longitudinal direction of the sensor unit 32 and is installed on the upper or lower surface of the protective sheet 37A. The support plate is made of, for example, ABS resin. As an example, the dimensions of the support plate can be set to a length of 700 mm, a width of 180 mm, and a thickness of 0.4 mm. By providing a support plate to the sensor unit 32, the sensor unit 32 can be installed flat even if, for example, the shape of the floorboard 220 is not flat, so that a stable load can be obtained on the first pressure sensor 10.

[0031] The protective sheets 37A, 37B, and 37C, which serve as protective components, are flexible and insulating sheet materials, made of, for example, PVC (i.e., polyvinyl chloride). As an example, the dimensions of protective sheet 37A can be set to a length of 720 mm, a width of 200 mm, and a thickness of 0.4 mm. The dimensions of protective sheets 37B and 37C can be set to a length of 700 mm, a width of 180 mm, and a thickness of 0.4 mm.

[0032] Seven thread members 38 are repeatedly installed at equal intervals along the longitudinal direction of the sensor unit 32. Each thread member 38 is installed linearly along the short direction of the sensor unit 32. Each thread member 38 also supports the first pressure sensor 10 via a protective sheet 37B. The thread members 38 are made of synthetic resin (e.g., nylon resin, PE resin, and fluororesin), or high-carbon steel wire. As an example, the thread member 38 is a fishing line with a length of 170 mm and a diameter of 1.48 mm. The thread members 38 are made of an insulator with hardness that is resistant to deformation when subjected to pressure from the human body, or they do not need to be an insulator as long as they are in contact with the first pressure sensor 10 via an insulating material. The thread members 38 may also be installed at different intervals along the longitudinal direction of the sensor unit 32. The thread members 38 may also be installed in a straight line diagonally to the short direction of the sensor unit 32.

[0033] The first pressure sensor 10 is a linear sensor that detects the radial pressure applied by a person lying on the mattress 230, and generates a voltage when pressure is received. The first pressure sensor 10 is electrically connected to the information processing unit 40 via a coaxial cable 110 which serves as wiring. The detailed structure of the first pressure sensor 10 will be described later. With the structure described later, the first pressure sensor 10 functions as a sensor capable of acquiring biological information through pressure. Here, biological information includes heart rate, respiratory rate, body movement, blood pressure, sweating, electroencephalogram, body temperature, stress level, voice volume, etc. Here, the first pressure sensor 10 is an example of the "first sensor".

[0034] Furthermore, the first pressure sensor 10 consists of a single linear sensor extending in the short direction of the sensor unit 32, and three linear sensors branching off from this sensor and extending in the longitudinal direction D1 of the sensor unit 32. The three linear sensors are arranged parallel to each other. For example, the three linear sensors can be installed branched off at 70 mm intervals in the short direction of the sensor unit 32. Here, "parallel" includes a state of approximately parallel, where the three linear sensors appear to be parallel at first glance. Specifically, "approximately parallel" means that the angle between the three linear sensors is less than 10 degrees.

[0035] Furthermore, as shown in Figure 2B, the sensor unit 32 has its components arranged in the following order along the direction of pressure from the person lying in bed (i.e., the direction of arrow P): protective sheet 37C, first pressure sensor 10, protective sheet 37B, thread member 38, and protective sheet 37A. The biological information detection device 50 can detect the strain caused by the deformation of the first pressure sensor 10 as pressure from the person lying in bed 200. Here, by installing the first pressure sensor 10 in a direction perpendicular to the upper part of the thread member 38, a space S (see Figure 2A) is formed in which strain can be generated in the first pressure sensor 10 when pressure is applied from the direction of arrow P. That is, when pressure from the person lying in bed 200 is applied to the first pressure sensor 10, the first pressure sensor 10 deforms in space S so as to wrap around the thread member 38 with the thread member 38 as a fulcrum. Therefore, biological information can be acquired with higher accuracy compared to the case where space S does not exist and the amount of deformation of the first pressure sensor 10 is small. The thread member 38 may also be installed on the upper surface of the protective sheet 37B.

[0036] (Example of a sensor unit) Figure 2C is a top view of a modified sensor unit 32 of the first embodiment. The modified sensor unit 32 is equipped with a support plate 36B. Note that Figure 2C shows the sensor unit 32 with the protective sheet 37C removed.

[0037] As shown in Figure 2C, the sensor unit 32 comprises a protective sheet 37A, a protective sheet 37C (not shown), a support plate 36B, a plurality of thread members 38, a first pressure sensor 10, and a coaxial cable 110. The protective sheet 37A is the part that is placed directly on the floor plate 220. The support plate 36B is installed on top of the protective sheet 37A. The plurality of thread members 38 are installed on top of the support plate 36B. The first pressure sensor 10 is installed on top of the support plate 36B and on top of each thread member 38 on the upper surface of the support plate 36B. The protective sheet 37C is installed on top of the support plate 36B and on top of the first pressure sensor 10 on the upper surface of the support plate 36B. The coaxial cable 110 is electrically connected to the first pressure sensor 10. The components are bonded to each other using double-sided tape and adhesive. Furthermore, in the areas where the first pressure sensor 10 protrudes without following the thread member 38, spaces S are formed on both sides of the thread member 38. The support plate 36B is an example of a "base material".

[0038] The dimensions of the protective sheet 37A and protective sheet 37C, which serve as protective components, can be set, for example, to a length of 720 mm, a width of 205 mm, and a thickness of 0.4 mm.

[0039] The support plate 36B is a plate-shaped member that serves as the substrate for the sensor unit 32, and is made of, for example, ABS resin. As an example, the dimensions of the support plate 36B can be set to a length of 700 mm, a width of 185 mm, and a thickness of 1.5 mm.

[0040] The first pressure sensor 10 consists of a single linear sensor extending in the short direction of the sensor unit 32, and two linear sensors branching off from this sensor and extending in direction D1. The two linear sensors are arranged parallel to each other. For example, the two linear sensors can be installed branching off at 125 mm intervals in the short direction of the sensor unit 32. Here, "parallel" includes a state of approximately parallel, where the two linear sensors appear to be parallel at first glance. Specifically, "approximately parallel" means that the angle between the two linear sensors is less than 10 degrees.

[0041] The thread members 38 are members that support the two linear sensors of the first pressure sensor 10. Seven thread members 38 are installed repeatedly at equal intervals below each of the two linear sensors that extend in the direction D1. In addition, each of the thread members 38 is installed in a straight line along the shorter direction of the sensor unit 32. As an example, the thread members 38 are fishing lines with a length of 30 mm and a diameter of 1.48 mm.

[0042] (Information Processing Unit) The information processing unit 40 (see Figure 1) detects the output signal from the sensor unit 32. As shown in Figure 3, the information processing unit 40 includes an AD converter 42 that converts the voltage output, which is an analog signal output from the first pressure sensor 10 through the amplifier circuit 43, into a digital signal, and a processing PC 50 that detects the converted digital signal from the first pressure sensor 10. The AD converter 42 is provided with multiple input terminals for inputting analog signals, and the first pressure sensor 10 is electrically connected to one of these input terminals. A filter circuit may be provided between the first pressure sensor 10 and the AD converter 42, and in particular between the amplifier circuit 43 and the AD converter 42, if necessary.

[0043] The processing PC 41 consists of a CPU (Central Processing Unit) 41A, ROM (Read Only Memory) 41B, RAM (Random Access Memory) 41C, storage 41D, communication interface 41E, monitor 41F, and input / output interface 40G. The CPU 41A, ROM 41B, RAM 41C, storage 41D, communication interface 41E, monitor 41F, and input / output interface 40G are interconnected via bus 41H to enable communication with each other. The processing PC 41 includes not only personal computers but also computers such as smartphones.

[0044] The CPU 41A is a central processing unit that executes various programs and controls various parts. Specifically, the CPU 41A reads programs from the ROM 41B or storage 41D and executes the programs using the RAM 41C as a working area. In this embodiment, the storage 41D stores execution programs for performing various processes. By executing the execution programs, the CPU 41A functions as the detection unit 55, determination unit 56, and notification unit 57 shown in Figure 4.

[0045] ROM41B stores various programs and data. RAM41C temporarily stores programs or data as a working area. Storage41D, which serves as a memory unit, is composed of an HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs, including the operating system, and various data.

[0046] The communication interface F41E is an interface for communicating with mobile devices such as smartphones, and uses standards such as Ethernet (registered trademark), FDDI, Wi-Fi (registered trademark), and Bluetooth (registered trademark).

[0047] The input / output interface 40G is an interface for communicating with each device that makes up the information processing unit 40. In this embodiment, the processing PC 41 is connected to the AD converter 42 via the input / output interface 40G.

[0048] (Functional Configuration) Figure 4 is a block diagram showing an example of the functional configuration of the CPU 41A. As shown in Figure 4, the CPU 41A has a detection unit 55, a determination unit 56, and a notification unit 57. Each functional configuration is realized by the CPU 41A reading an executable program stored in the storage 41D and executing it.

[0049] The detection unit 55 has the function of detecting the digital signal related to the first pressure sensor 10 output from the AD converter 42 via the communication I / F 41E.

[0050] Furthermore, the detection unit 55 has a function to detect biological information. For example, the determination unit 56 detects the respiration and heart rate of a person lying on the bed 200 from the waveform of the voltage output of the first pressure sensor 10.

[0051] The determination unit 56 has the function of determining whether a person is lying on the bed 200 or sitting up, based on the detection result of the first pressure sensor 10 detected by the detection unit 55. For example, if the voltage output of the first pressure sensor 10 fluctuates beyond a predetermined threshold, the determination unit 56 determines whether the person has transitioned from lying down to sitting up, or from sitting up to lying down. The determination unit 56 may determine that a person is lying on the bed 200 if biological information is detected from the waveform of the voltage output of the first pressure sensor 10. Alternatively, the determination unit 56 may determine that something other than a person is on the bed 200 if no biological information is detected from the waveform of the voltage output of the first pressure sensor 10.

[0052] The notification unit 57 has the function of notifying the judgment result made by the judgment unit 56. For example, the notification unit 57 can output text information related to the judgment result to the monitor 41F or output audio information related to the judgment result to a speaker (not shown). It can also transmit the judgment result to an external device, such as the caregiver's mobile phone, via the communication interface 41E.

[0053] (First pressure sensor) Next, the details of the first pressure sensor 10 will be described with reference to Figures 5 and 6. Figure 5 is a front view showing one aspect of the first pressure sensor 10 according to this embodiment. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 5.

[0054] As shown in Figures 5 and 6, the first pressure sensor 10 includes an internal conductor 11, a piezoelectric element 12, and an external conductor 13. The internal conductor 11 extends in direction D1. The piezoelectric element 12 covers at least a portion of the internal conductor 11. The external conductor 13 is arranged on the outer circumference of the piezoelectric element 12. Furthermore, when an external force F acts on the piezoelectric element 12, the first pressure sensor 10 generates a first voltage between the inner conductor 11 and the outer conductor 13 due to the displacement of the piezoelectric element 12 caused by the external force F. The first voltage represents the potential difference of the inner conductor 11 relative to the outer conductor 13.

[0055] The external force F includes tension, pressure, and bending. The displacement of the piezoelectric element 12 includes the returnable deformation of the piezoelectric element 12 in response to the external force F (hereinafter referred to as "nonplastic deformation"). The nonplastic deformation of the piezoelectric element 12 includes partial or total elongation and compression of the piezoelectric element 12.

[0056] The pressure sensor 10 is a linear object. The cross-sectional shape of the pressure sensor 10 in a plane perpendicular to direction D1 is appropriately adjusted according to the application of the bio-information detection device 50, and examples include circular, elliptical, rectangular, cocoon-shaped, four-leaf clover-shaped, star-shaped, and irregular shapes. When the cross-sectional shape of the pressure sensor 10 is circular, the diameter of the pressure sensor 10 is preferably 0.1 mm or more and 10 mm or less. The length of the pressure sensor 10 in direction D1 is appropriately adjusted according to the application of the bio-information detection device 50, and is, for example, 1 mm or more and 100 mm or less.

[0057] <Internal conductor> The internal conductor 11 is a conductor for efficiently detecting electrical signals from the pressure sensor 10. The internal conductor 11 is preferably an electrical conductor, and examples include copper wire, aluminum wire, SUS (Steel Use Stainless) wire, insulated metal wire, carbon fiber, resin fiber integrated with carbon fiber, silk thread, and organic conductive material. Silk thread is formed by spirally winding copper foil around a fiber. The outer diameter of the fiber is appropriately adjusted according to the desired characteristics of the first pressure sensor 10, and is preferably 0.1 mm or more and 10 mm or less. Among these, the internal conductor 11 is preferably silk thread or carbon fiber from the viewpoint of improving piezoelectric sensitivity and the stability of piezoelectric output and providing high flexibility, and in particular, silk thread is preferred from the viewpoint of low electrical resistance.

[0058] <External conductor> The outer conductor 13 is a pair of conductors to the inner conductor 11 for detecting electrical signals from the first pressure sensor 10. The outer conductor 13 only needs to be positioned on the outer circumference of the piezoelectric element 12, and may cover at least a part of the piezoelectric element 12. More specifically, the outer conductor 13 may cover a part of the outer surface of the piezoelectric element 12, or it may cover the entire outer surface of the piezoelectric element 12. The outer conductor 13 is formed, for example, by winding a long conductor. The cross-sectional shape of the elongated conductor can be, for example, circular, elliptical, rectangular, or irregularly shaped. Among these, a rectangular cross-sectional shape is preferred from the viewpoint of making close contact with the piezoelectric element 12 in a planar manner and efficiently generating voltage. The material for the elongated conductor is not particularly limited, and depending on the cross-sectional shape, the following are the main examples. Examples of long conductors with a rectangular cross-section include copper foil ribbons and aluminum foil ribbons, which are made by rolling a circular cross-section copper wire into a flat plate. Examples of long conductors with a circular cross-section include copper wire, aluminum wire, SUS wire, metal wire with an insulating coating, carbon fiber, resin fiber integrated with carbon fiber, and brocade wire in which copper foil is spirally wound around a fiber. Alternatively, a long conductor may be made of an organic conductive material coated with an insulating material. Methods for winding a long conductor include, for example, winding copper foil or the like in a spiral around the piezoelectric element 12, forming a cylindrical braid of copper wire or the like and wrapping it around the piezoelectric element 12, or enclosing the piezoelectric element 12 in a cylindrical shape.

[0059] <Piezoelectric> When an external force F acts on the piezoelectric element 12, it generates a voltage between the inner conductor 11 and the outer conductor 13. The piezoelectric element 12 only needs to cover at least a portion of the internal conductor 11, and may cover a portion of the outer surface of the internal conductor 11, or it may cover the entire outer surface of the internal conductor 11.

[0060] In configuration A of the piezoelectric body 12, the piezoelectric body 12 is formed by winding a long organic piezoelectric body 121, as shown in Figure 5.

[0061] (Long organic piezoelectric material) The elongated organic piezoelectric body 121 is made of an organic piezoelectric material, and has a piezoelectric constant d 14 It has.

[0062] The elongated organic piezoelectric material 121 is an elongated object. Examples of the shape of the elongated organic piezoelectric material 121 include a ribbon shape and a fiber shape. The ribbon shape is flat and elongated. The fiber shape may be in the form of a monofilament or a multifilament.

[0063] When the elongated organic piezoelectric material 121 is ribbon-shaped, the width of the elongated organic piezoelectric material 121 is preferably 0.1 mm or more and 30 mm or less. A width of 0.1 mm or more ensures the strength of the elongated organic piezoelectric material 121. Furthermore, it also provides excellent manufacturability (for example, manufacturability in the slitting process described later). A width of 30 mm or less improves the degree of freedom (flexibility) of nonplastic deformation of the elongated organic piezoelectric material 121. When the elongated organic piezoelectric material 121 is ribbon-shaped, the thickness of the elongated organic piezoelectric material 121 is preferably 0.001 mm or more and 0.2 mm or less. A thickness of 0.001 mm or more ensures the strength of the elongated organic piezoelectric material 121. Furthermore, it also provides excellent manufacturability for the elongated organic piezoelectric material 121. A thickness of 0.2 mm or less improves the degree of freedom (flexibility) of nonplastic deformation in the thickness direction of the elongated organic piezoelectric material 121. When the elongated organic piezoelectric material 121 is ribbon-shaped, it is preferable that the ratio of the width of the elongated organic piezoelectric material 121 to the thickness of the elongated organic piezoelectric material 121 (hereinafter referred to as "ratio [width / thickness]") is 2 or more. A ratio [width / thickness] of 2 or more clearly defines the main surface of the elongated organic piezoelectric material 121. Therefore, the elongated organic piezoelectric material 121 is easily wound around the first outer conductor 13 with its orientation aligned along its length. As a result, the first pressure sensor 10 has excellent piezoelectric sensitivity and also excellent stability of piezoelectric sensitivity.

[0064] When the elongated organic piezoelectric material 121 is fibrous, examples of cross-sectional shapes of the elongated organic piezoelectric material 121 include circular, elliptical, rectangular, cocoon-shaped, four-leaf clover-shaped, star-shaped, and irregular shapes. The major axis diameter of the cross-section of the elongated organic piezoelectric material 121 is preferably 0.0001 mm to 10 mm, more preferably 0.001 mm to 5 mm, and even more preferably 0.002 mm to 1 mm. The "major axis diameter of the cross-section" corresponds to the "diameter" when the cross-sectional shape of the elongated organic piezoelectric material 121 is circular, and when the cross-sectional shape of the elongated organic piezoelectric material 121 is not circular, it is the longest width within the width of the cross-section. When the fiber shape consists of multiple filaments, the "major axis diameter of the cross-section" refers to the major axis diameter of the cross-section of the multiple filaments.

[0065] The organic piezoelectric material has a long organic piezoelectric body 121 with a piezoelectric constant d 14 Any material that has the property can be used, for example, an optically active polymer (A). Examples of optically active polymers (A) include optically active helical chiral polymers (A1) (hereinafter sometimes referred to as "helical chiral polymer (A1)") and optically active polypeptides (A2) (hereinafter sometimes referred to as "optically active polypeptide (A2)").

[0066] "Optically active helical chiral polymers (A1)" refer to polymers that have a helical molecular structure and possess molecular optical activity. Examples of helical chiral polymers (A1) include polylactic acid polymers, synthetic polypeptides, cellulose derivatives, polypropylene oxides, and poly(β-hydroxybutyric acid). Polylactic acid polymers include L-lactic acid homopolymers (hereinafter referred to as "PLLA") and D-lactic acid homopolymers (hereinafter referred to as "PDLA"). PLLA has a left-handed helical molecular structure. PDLA has a right-handed helical molecular structure. Examples of synthetic polypeptides include poly(γ-benzyl glutarate) and poly(γ-methyl glutarate). Examples of cellulose derivatives include cellulose acetate and cyanoethylcellulose. Details of the polylactic acid polymer and the helical chiral polymer (A1) will be described later.

[0067] An "optically active polypeptide (A2)" refers to a polypeptide that has an asymmetric carbon atom and exhibits an uneven distribution of optical isomers. From the viewpoint of piezoelectricity and strength, optically active polypeptides (A2) preferably have a β-sheet structure. Examples of optically active polypeptides (A2) include optically active animal proteins. Examples of animal proteins include fibroin and spider silk protein. Examples of fibers made from animal proteins include silk and spider silk. Details about animal proteins will be discussed later.

[0068] In particular, organic piezoelectric materials preferably contain an optically active polymer (A), especially a helical chiral polymer (A1) or an optically active polypeptide (A2), from the viewpoint of good piezoelectric properties, processability, and availability. Furthermore, the helical chiral polymer (A1) preferably contains a polylactic acid-based polymer. The optically active polypeptide (A2) preferably contains an animal protein. Both the polylactic acid polymer and the optically active polypeptide (A2) are non-pyroelectric. By including either the polylactic acid polymer or the optically active polypeptide (A2) in the organic piezoelectric material, the first pressure sensor 10 exhibits improved piezoelectric sensitivity stability and piezoelectric output stability (stability against changes over time or temperature) compared to a pressure sensor using pyroelectric PVDF. Furthermore, the optically active polypeptide (A2) exhibits excellent hydrolysis resistance in high-temperature and high-humidity environments. The first pressure sensor 10 containing the optically active polypeptide (A2) suppresses the decrease in the first voltage, especially in high-temperature and high-humidity environments, compared to, for example, the first pressure sensor 10 containing a polylactic acid polymer. Details of the helical chiral polymer (A) will be described later.

[0069] If the optically active polymer (A) is in the form of fibers, the shape of the elongated organic piezoelectric material 121 may be fiber-shaped or ribbon-shaped. If the optically active polymer (A) is in the form of fibers and the shape of the elongated organic piezoelectric material 121 is also in the form of fibers, the organic piezoelectric material may consist only of the optically active polymer (A). When the optically active polymer (A) is in the form of fibers and the long organic piezoelectric body 121 is in the form of a ribbon, the organic piezoelectric material may contain the optically active polymer (A) and a resin. In this case, the organic piezoelectric material can be molded into a ribbon shape by the resin. When the organic piezoelectric material contains a plurality of fiber-shaped polymer materials (A), each of the plurality of optically active polymers (A) may be joined together by a resin. The resin includes at least one of a thermoplastic resin and a thermosetting resin. Examples of thermoplastic resins include polymethacrylic resins, polyacrylic resins, aromatic polyether ketones, and polyarylene resins. Examples of polymethacrylic resins include polymethacrylic resins, polyolefin resins, and polymethyl methacrylate resins. Examples of polyacrylic resins include polymethyl polyacrylate resins. Examples of aromatic polyether ketones include polystyrene resins, polyvinyl acetal resins, polycarbonate resins, and polyphenylene ether resins. Examples of polyarylene resins include polyphenylene oxide resins and polyphenylene sulfide (PPS) resins. These thermoplastic resins may be used individually or in combination of two or more types. Examples of thermosetting resins include epoxy resins, phenolic resins, unsaturated polyester resins, thermosetting polyimide resins, bismaleimidotriazine resins, and benzoxazine resins. These thermosetting resins may be used individually or in combination of two or more types.

[0070] The elongated organic piezoelectric material 121 preferably has the following first composition. In the first composition, The organic piezoelectric material contains an optically active polymer (A), The longitudinal direction of the elongated organic piezoelectric material 121 and the main orientation direction of the optically active polymer (A) contained in the elongated organic piezoelectric material 121 are substantially parallel (parallel to the double arrow D2 in Figure 5). The degree of orientation F of the elongated organic piezoelectric material 121, determined by the following formula (a) from X-ray diffraction measurements, is in the range of 0.5 or more and less than 1.0. Orientation degree F=(180°−α) / 180°··(a) However, α represents the full width at half maximum of the orientation-derived peak. The unit of α is degrees (°).

[0071] The degree of orientation F of the elongated organic piezoelectric material 121 is an index indicating the degree of orientation of the optically active polymer (A) contained in the elongated organic piezoelectric material 121. The degree of orientation F of the elongated organic piezoelectric material 121 is the c-axis orientation, measured, for example, by a wide-angle X-ray diffractometer (Rigaku RINT2550, accessory equipment: rotating sample stage, X-ray source: CuKα, output: 40kV 370mA, detector: scintillation counter). The degree of orientation F of the elongated organic piezoelectric material 121 is preferably 0.50 or more and 0.99 or less, more preferably 0.70 or more and 0.98 or less, and particularly preferably 0.80 or more and 0.97 or less. In the elongated organic piezoelectric material 121, the fact that the longitudinal direction of the elongated organic piezoelectric material 121 and the principal orientation direction of the optically active polymer (A) contained in the elongated organic piezoelectric material 121 are substantially parallel also contributes to the expression of piezoelectricity. The fact that the longitudinal direction of the elongated organic piezoelectric material 121 and the principal orientation direction of the optically active polymer (A) contained in the elongated organic piezoelectric material 121 are substantially parallel also has the advantage that the elongated organic piezoelectric material 121 has excellent tensile strength in its longitudinal direction. Therefore, when the elongated organic piezoelectric material 121 is wound spirally around the internal conductor 11, the elongated organic piezoelectric material 121 is less likely to break.

[0072] "Approximately parallel" means that the angle between the two line segments is 0° or more and less than 30°. Preferably, the angle between the two line segments is 0° or more and 22.5° or less, more preferably 0° or more and 10° or less, even more preferably 0° or more and 5° or less, and particularly preferably 0° or more and 3° or less. For example, when an organic piezoelectric material includes silk or spider silk, which are examples of fibers made of animal protein, the longitudinal direction of the silk or spider silk and the principal orientation direction of the optically active polypeptide (A2) (for example, fibroin or spider silk protein, which are examples of animal protein) are approximately parallel during the process of producing the silk or spider silk.

[0073] The primary orientation direction of the optically active polymer (A) refers to the main orientation direction of the optically active polymer (A). The primary orientation direction of the optically active polymer (A) can be confirmed, for example, by measuring the degree of orientation F of the elongated organic piezoelectric material 121. When the elongated organic piezoelectric material 121 is manufactured by stretching a film and forming slits in the stretched film, the main orientation direction of the optically active polymer (A) in the elongated organic piezoelectric material 121 refers to the main stretching direction. Here, the main stretching direction refers to the stretching direction in the case of uniaxial stretching, and to the stretching direction with the higher stretching ratio in the case of biaxial stretching.

[0074] The following describes the case where the elongated organic piezoelectric material 121 has the first composition and the optically active polymer (A) is a helical chiral polymer (A1).

[0075] A method for manufacturing the elongated organic piezoelectric material 121 includes, for example, forming a raw material (e.g., optically active polymer (A)) into a film to obtain an unstretched film, subjecting the obtained unstretched film to stretching and crystallization, and slitting the obtained organic piezoelectric film. Here, "slitting" means cutting the organic piezoelectric film into long lengths. Note that stretching and crystallization may be performed in any order. Alternatively, the unstretched film may be subjected to pre-crystallization, stretching, and crystallization (annealing) in sequence. Stretching may be uniaxial or biaxial. In the case of biaxial stretching, it is preferable to increase the stretching ratio in one direction (the main stretching direction). For information on methods for manufacturing organic piezoelectric films, refer to publicly available documents such as Japanese Patent No. 4934235, International Publication No. 2010 / 104196, International Publication No. 2013 / 054918, and International Publication No. 2013 / 089148 as appropriate. The elongated organic piezoelectric material 121 will be described later.

[0076] [Piezoelectric material configuration A] Next, with reference to Figures 5 and 6, the configuration A of the piezoelectric element 12 will be described.

[0077] As shown in Figure 5, the elongated organic piezoelectric material 121 is wound counterclockwise (left-handed) in the direction D1. More specifically, it is wound spirally in the spiral direction D2 along the outer surface of the inner conductor 11 at a spiral angle β1 in the direction D1, without any gaps. This wound elongated organic piezoelectric material 121 constitutes the piezoelectric body 12. "Spiral angle β1" refers to the angle formed by the axial direction AX of the internal conductor 11 and the direction of arrangement of the elongated organic piezoelectric element 121 relative to the axial direction AX of the internal conductor 11. The helical angle β1 is preferably 15° to 75° (45°±30°), and more preferably 35° to 55° (45°±10°). "Spiral direction D2" refers to the direction in which the elongated organic piezoelectric material 121 is wound toward direction D1.

[0078] Next, the function of the piezoelectric element configuration A will be explained. For example, when tension (stress) is applied to the first pressure sensor 10 in a direction parallel to the axial direction AX, shear strain is applied to the helical chiral polymer (A1) contained in the elongated organic piezoelectric material 121, causing polarization of the helical chiral polymer (A1) in the radial direction of the first pressure sensor 10. This polarization direction is determined when the piezoelectric material 12 of configuration A, in which the elongated organic piezoelectric material 121 is wound in a helical shape, is considered as an aggregate of minute regions that can be treated as a plane with respect to the axial direction AX, and when a shear force caused by tension (stress) is applied to the helical chiral polymer (A1) in the plane of the minute regions that constitute it, the piezoelectric constant d 14 The direction of the electric field generated by this substantially coincides with the direction of the electric field. Specifically, the polarization of the helical chiral polymer (A1) occurs radially in the first pressure sensor 10, as indicated by the arrow in Figure 6, and it is thought that the polarization direction occurs with aligned phases. As a result, the first pressure sensor 10 becomes more efficient at generating a first voltage proportional to the external force F. Based on the above, the piezoelectric element configuration A results in the first pressure sensor 10 having excellent piezoelectric sensitivity and excellent stability of piezoelectric output.

[0079] In configuration A, when the helical chiral polymer (A1) is PLLA, when tension acts on the first pressure sensor 10 in a direction parallel to the axial direction AX, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the tension, extending outward from the center of the circular cross-section. In other words, the sign of the first voltage is positive. In configuration A, when the helical chiral polymer (A1) is PLLA, when pressure is applied to the first pressure sensor 10 in a direction parallel to the axial direction AX, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the pressure, extending from the outside of the circular cross-section toward the center. In other words, the sign of the first voltage becomes negative.

[0080] In configuration A, when the helical chiral polymer (A1) is PDLA, the positive and negative signs of the first voltage are reversed compared to when the helical chiral polymer (A1) is PLLA. Specifically, in configuration A, when the helical chiral polymer (A1) is PDLA, when tension acts on the first pressure sensor 10 in a direction parallel to the axial direction AX, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the tension, extending from the outside of the circular cross-section toward the center. In other words, the sign of the first voltage becomes negative. In configuration A, when the helical chiral polymer (A1) is PDLA, when pressure is applied to the first pressure sensor 10 in a direction parallel to the axial direction AX, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the pressure, extending outward from the center of the circular cross-section. In other words, the sign of the first voltage is positive.

[0081] Furthermore, in configuration A, the elongated organic piezoelectric material 121 is wound counterclockwise in the direction D1, but the configuration of the piezoelectric material 12 may be one in which the elongated organic piezoelectric material 121 is wound clockwise in the direction D1 (hereinafter referred to as "configuration A'").

[0082] In configuration A', when the helical chiral polymer (A1) is PLLA, the sign of the first voltage is the opposite of that in configuration A when the helical chiral polymer (A1) is PLLA. Specifically, in configuration A', when the helical chiral polymer (A1) is PLLA, when tension acts on the first pressure sensor 10 in a direction parallel to the axial direction AX, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the tension, extending from the outside of the circular cross-section toward the center. In other words, the sign of the first voltage becomes negative. In configuration A', when the helical chiral polymer (A1) is PLLA, when pressure is applied to the first pressure sensor 10 in a direction parallel to the axial direction AX, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the pressure, extending outward from the center of the circular cross-section. In other words, the sign of the first voltage becomes positive.

[0083] In configuration A', when the helical chiral polymer (A1) is PDLA, the sign of the first voltage is the opposite of that in configuration A when the helical chiral polymer (A1) is PDLA. Specifically, in configuration A', when the helical chiral polymer (A1) is PDLA, when tension acts on the first pressure sensor 10, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the tension, extending outward from the center of the circular cross-section. In other words, the sign of the first voltage becomes positive. In configuration A', when the helical chiral polymer (A1) is PDLA, when pressure is applied to the first pressure sensor 10, an electric field (polarization) is generated parallel to the radial direction and perpendicular to the pressure, extending from the outside of the circular cross-section towards the center. In other words, the sign of the first voltage becomes negative.

[0084] The piezoelectric element 12 is not limited to the configuration A described above, but may have other configurations. For example, the piezoelectric element 12 may have a second long organic piezoelectric element wound around it in addition to the long organic piezoelectric element 121. The second long organic piezoelectric element is wound spirally along the outer surface of the long organic piezoelectric element 121 in the opposite direction to the winding direction of the long organic piezoelectric element 121. Alternatively, the piezoelectric element 12 may have a braided structure wound around it. The braided structure is made by alternately crossing the long organic piezoelectric element 121 and the second long organic piezoelectric element.

[0085] <Adhesive layer> The first pressure sensor 10 may have an adhesive layer. The adhesive layer is placed, for example, between the internal conductor 11 and the piezoelectric element 12. This suppresses the occurrence of a displacement in the relative position between the piezoelectric element 12 and the internal conductor 11, even if, for example, tension caused by an external force acts on the first pressure sensor 10 in the axial direction AX of the internal conductor 11. The axial direction AX and direction D1 are parallel. Furthermore, the elongated organic piezoelectric element 121 is more susceptible to tension caused by external forces. Examples of adhesive materials used to form the adhesive layer include epoxy adhesives, urethane adhesives, vinyl acetate resin emulsion adhesives, ethylene vinyl acetate (EVA) emulsion adhesives, acrylic resin emulsion adhesives, styrene-butadiene rubber latex adhesives, silicone resin adhesives, α-olefin (isobutene-maleic anhydride resin) adhesives, vinyl chloride resin solvent adhesives, rubber adhesives, elastic adhesives, chloroprene rubber solvent adhesives, nitrile rubber solvent adhesives, cyanoacrylate adhesives, and others.

[0086] <First insulator> The first pressure sensor 10 may have a first insulator. The first insulator is placed, for example, between the piezoelectric element 12 and the inner conductor 11, and between the piezoelectric element 12 and the outer conductor 13, at least one of the two. This can further suppress the occurrence of a short circuit between the inner conductor 11 and the outer conductor 13. The first insulator is, for example, formed by spirally winding a long, rectangular object along the outer surface of the internal conductor 11. The material for the first insulator can be any material that has electrical insulating properties, such as polyvinyl chloride resin, polyethylene resin, polypropylene resin, ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluoropropyl vinyl ether copolymer (PFA), fluororubber, polyester resin, polyimide resin, polyamide resin, polyethylene terephthalate resin (PET), rubber (including elastomers), etc.

[0087] <Second insulator> The first pressure sensor 10 may have a second insulator. The second insulator is placed on the outer circumference of the outer conductor 13. The second insulator may cover the entire outer circumference of the outer conductor 13. This makes it possible to electrostatically shield the inner conductor 11 and suppress voltage changes in the first voltage due to the influence of external static electricity. The material of the second insulator can be any material that has electrical insulating properties, and may be the same material as the material exemplified for the first insulator.

[0088] <Functional Layer> The first pressure sensor 10 may have a functional layer. The functional layer is disposed, for example, between the piezoelectric element 12 and the internal conductor 11, and between the piezoelectric element 12 and the external conductor 13, at least one of the two. Examples of layers that make up the functional layer (hereinafter referred to as "constituent layers") include an easy-adhesion layer, a hard coat layer, a refractive index adjustment layer, an anti-reflection layer, an anti-glare layer, a smooth-slip layer, an anti-blocking layer, a protective layer, an adhesive layer, an antistatic layer, a heat dissipation layer, an ultraviolet absorption layer, an anti-Newton ring layer, a light scattering layer, a polarizing layer, a gas barrier layer, a hue adjustment layer, and an electrode layer. The functional layer may be a single-layer structure consisting of one constituent layer, or it may be a multi-layer structure consisting of two or more constituent layers. If the functional layer has a multi-layer structure, each of the multiple constituent layers may be the same or different. If the first pressure sensor 10 has a functional layer between the piezoelectric element 12 and the internal conductor 11, and between the piezoelectric element 12 and the external conductor 13, the functional layer between the piezoelectric element 12 and the internal conductor 11 and the functional layer between the piezoelectric element 12 and the external conductor 13 may be the same or different. The thickness of the functional layer is not particularly limited, but is preferably in the range of 0.01 μm to 10 μm. The material of the functional layer is appropriately selected according to the function required of the functional layer, and examples include inorganic materials such as metals and metal oxides; organic materials such as resins; and composite compositions containing resins and fine particles. Examples of resins include cured products obtained by curing with temperature or active energy rays.

[0089] (Helical chiral polymer (A1)) Next, we will explain helical chiral polymers (A1).

[0090] From the viewpoint of further improving piezoelectricity, the helical chiral polymer (A1) preferably has an optical purity of 95.00%ee or higher. From the viewpoint of further improving piezoelectricity, the helical chiral polymer (A1) preferably consists of a D-form or an L-form. From the viewpoint of further improving piezoelectricity, the content of the helical chiral polymer (A1) preferably is 80% by mass or more of the total amount of the elongated organic piezoelectric material 121.

[0091] The optical purity of the helical chiral polymer (A1) is preferably 95.00%ee or higher, more preferably 96.00%ee or higher, even more preferably 99.00%ee or higher, particularly preferably 99.99%ee or higher, and most preferably 100.00%ee, from the viewpoint of improving the piezoelectricity of the elongated organic piezoelectric material 121. By setting the optical purity of the helical chiral polymer (A1) within the above range, the packing properties of the piezoelectric polymer crystals are improved, and as a result, the piezoelectricity is enhanced.

[0092] The optical purity of the helical chiral polymer (A1) is calculated using the following formula. Optical purity (%ee) = 100 × |L volume - D volume | / (L volume + D volume) In other words, the optical purity of the helical chiral polymer (A1) is, This value is obtained by multiplying the result of dividing the "absolute difference (absolute value) between the amount of the L-form of helical chiral polymer (A1) [mass%] and the amount of the D-form of helical chiral polymer (A1)" by the "total amount of the L-form of helical chiral polymer (A1) [mass%] and the D-form of helical chiral polymer (A1) [mass%]" by "100".

[0093] The amounts of the L-isomer [mass%] and D-isomer [mass%] of the helical chiral polymer (A1) will be values ​​obtained using high-performance liquid chromatography (HPLC). Specific measurement details will be described later.

[0094] -Weight average molecular weight- The weight-average molecular weight (Mw) of the helical chiral polymer (A1) is preferably between 50,000 and 1,000,000. The mechanical strength of the elongated organic piezoelectric material 121 is improved when the Mw of the helical chiral polymer (A1) is 50,000 or more. The above Mw is preferably 100,000 or more, and more preferably 200,000 or more. Having a Mw of 1 million or less for the helical chiral polymer (A1) improves the moldability when obtaining the long organic piezoelectric material 121 by molding (e.g., extrusion molding, melt spinning). Preferably, the Mw of the helical chiral polymer (A1) is 800,000 or less, and more preferably 300,000 or less.

[0095] The molecular weight distribution (Mw / Mn) of the helical chiral polymer (A1) is preferably 1.1 to 5, more preferably 1.2 to 4, from the viewpoint of the strength of the elongated organic piezoelectric material 121. Furthermore, it is preferable that it be 1.4 to 3.

[0096] The weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the helical chiral polymer (A1) refer to values ​​measured using gel permeation chromatography (GPC). Here, Mn is the number-average molecular weight of the helical chiral polymer (A1). The following is an example of a method for measuring Mw and Mw / Mn of a helical chiral polymer (A1) using GPC.

[0097] -GPC measurement device- Waters GPC-100 -column- Shodex LF-804, manufactured by Showa Denko Corporation. -Sample Preparation- A long organic piezoelectric material 121 is dissolved in a solvent (e.g., chloroform) at 40°C to prepare a sample solution with a concentration of 1 mg / ml. -Measurement conditions- 0.1 ml of the sample solution is introduced into the column with chloroform as the solvent, at a temperature of 40°C, and at a flow rate of 1 ml / min.

[0098] The sample concentration in the sample solution separated by the column is measured using a differential refractometer. A universal calibration curve is prepared using polystyrene standard samples, and the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the helical chiral polymer (A1) are calculated.

[0099] As an example of a helical chiral polymer (A1), commercially available polylactic acid can be used as a polylactic acid-based polymer. Examples of commercially available products include PURASORB (PD, PL) from PURAC, LACEA (H-100, H-400) from Mitsui Chemicals, and Ingeo from NatureWorks LLC. TM Examples include biopolymers, etc. When using a polylactic acid-based polymer as the helical chiral polymer (A1), it is preferable to produce the polylactic acid-based polymer by the lactide method or direct polymerization method in order to achieve a weight-average molecular weight (Mw) of 50,000 or more.

[0100] The elongated organic piezoelectric material 121 may contain only one type of helical chiral polymer (A1), or it may contain two or more types. The content of helical chiral polymer (A1) in the elongated organic piezoelectric material 121 (total content if there are two or more types) is preferably 80% by mass or more of the total amount of the elongated organic piezoelectric material 121.

[0101] (Polylactic acid polymer) Next, we will explain polylactic acid polymers.

[0102] As a polylactic acid polymer, it is preferable to have a main chain containing repeating units represented by the following formula (1) from the viewpoint of increasing optical purity and improving piezoelectricity.

[0103] [ka]

[0104] Polylactic acid polymers refer to "polylactic acid (a polymer consisting only of repeating units derived from monomers selected from L-lactic acid and D-lactic acid)", "a copolymer of L-lactic acid or D-lactic acid and a compound copolymerizable with said L-lactic acid or D-lactic acid", or a mixture thereof. Among polylactic acid polymers, polylactic acid is preferred, and PLLA or PDLA is most preferred.

[0105] Polylactic acid is a polymer formed by the polymerization of lactic acid through ester bonds, resulting in long chains of molecules. Methods for producing polylactic acid include the lactide method, which involves the lactide process; and the direct polymerization method, in which lactic acid is heated under reduced pressure in a solvent while removing water during polymerization. Examples of polylactic acid include block copolymers and graft copolymers. Block copolymers include homopolymers of L-lactic acid, homopolymers of D-lactic acid, and polymers of at least one of L-lactic acid and D-lactic acid. Graft copolymers include polymers of at least one of L-lactic acid and D-lactic acid.

[0106] Compounds copolymerizable with L-lactic acid or D-lactic acid include hydroxycarboxylic acids such as glycolic acid, dimethylglycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, 2-hydroxyvaleric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 2-hydroxycaproic acid, 3-hydroxycaproic acid, 4-hydroxycaproic acid, 5-hydroxycaproic acid, 6-hydroxycaproic acid, 6-hydroxymethylcaproic acid, and mandelic acid; cyclic esters such as glycolide, β-methyl-δ-valerolactone, γ-valerolactone, and ε-caprolactone; oxalic acid, malonic acid, succinic acid, and glutaryl acid. Examples include acids, polycarboxylic acids such as adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanediol, dodecanediol, and terephthalic acid, and their anhydrides; polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, tetramethylene glycol, and 1,4-hexanedimethanol; polysaccharides such as cellulose; aminocarboxylic acids such as α-amino acids; and so on.

[0107] Examples of "copolymers of L-lactic acid or D-lactic acid and compounds copolymerizable with said L-lactic acid or D-lactic acid" include block copolymers or graft copolymers having a polylactic acid sequence capable of generating helical crystals.

[0108] The concentration of structures derived from copolymer components in the polylactic acid polymer is preferably 20 mol% or less. For example, in a polylactic acid polymer, it is preferable that the concentration of the structure derived from the copolymer component is 20 mol% or less relative to the total number of moles of the structure derived from lactic acid and the structure derived from a compound copolymerizable with lactic acid (copolymer component).

[0109] Examples of methods for producing polylactic acid polymers include the method described in Japanese Patent Publication No. 59-096123 and Japanese Patent Publication No. 7-033861, which involves directly dehydrating and condensing lactic acid; and the method described in U.S. Patent No. 2,668,182, etc., which involves ring-opening polymerization using lactide, a cyclic dimer of lactic acid.

[0110] Furthermore, in order to achieve an optical purity of 95.00%ee or higher for the polylactic acid polymers obtained by each of the above manufacturing methods, it is preferable, for example, when producing polylactic acid by the lactide method, to polymerize lactide whose optical purity has been improved to 95.00%ee or higher by crystallization.

[0111] (Animal protein) The following describes an example of an optically active polypeptide (A2), namely an animal protein.

[0112] In addition to the fibroin and spider silk protein mentioned above, animal proteins include sericin, collagen, keratin, and elastin. In particular, the optically active polypeptide (A2) preferably contains at least one of fibroin and spider silk protein, and more preferably consists of at least one of fibroin and spider silk protein.

[0113] The spider silk protein may be natural spider silk protein, or derived from or similar to natural spider silk protein (hereinafter collectively referred to as "derived"), and is not particularly limited. "Derived from natural spider silk protein" refers to substances that have an amino acid sequence similar to or identical to the repeating amino acid sequence of natural spider silk protein. Examples of substances "derived from natural spider silk protein" include recombinant spider silk protein, mutants of natural spider silk protein, analogs of natural spider silk protein, and derivatives of natural spider silk protein.

[0114] As for spider silk proteins, those produced in the large bottle glands of spiders, such as the bookmark silk protein or spider silk proteins derived from the bookmark silk protein, are preferred from the viewpoint of having excellent toughness. Examples of large spindle bookmark proteins include MaSp1 or MaSp2, which are large bottle-shaped glandular spidoins derived from the golden orb-weaver spider (Nephila clavipes), and ADF3 or ADF4, which are derived from the garden spider (Araneus diadematus).

[0115] The spider silk protein may be a microspinal bookmark protein produced in the small vial-shaped glands of spiders, or a spider silk protein derived from a microspinal bookmark protein. Examples of microspinoid silk proteins include MiSp1 and MiSp2, which are small vial-shaped glandular spidoins derived from the golden orb-weaver spider (Nephila clavipes).

[0116] In addition, spider silk protein may also be transverse silk protein produced in the flagelliform gland of spiders, or spider silk protein derived from this transverse silk protein. Examples of transverse silk proteins include flagelliform silk protein derived from the orb-weaver spider (Nephila clavipes).

[0117] Examples of spider silk proteins derived from the large spindle bookmark protein mentioned above include recombinant spider silk proteins containing units of the amino acid sequence shown in formula (2) below. Recombinant spider silk protein may contain two or more units (preferably four or more, more preferably six or more) of the amino acid sequence shown in the following formula (2). If recombinant spider silk protein contains two or more units of the amino acid sequence shown in formula (2) below, the two or more units of the amino acid sequence may be the same or different.

[0118] REP1-REP2 … Formula (2) [In formula (2), REP1 is a polyalanine region mainly composed of alanine and represented by (X1)p, and REP2 is an amino acid sequence consisting of 10 to 200 amino acid residues.]

[0119] In formula (2), REP1 is a polyalanine region mainly composed of alanine and represented by (X1)p. REP1 is preferably polyalanine. In (X1)p, p is not particularly limited, but preferably an integer between 2 and 20, more preferably an integer between 4 and 12. In (X1)p, X1 represents alanine (Ala), serine (Ser), or glycine (Gly). In the polyalanine region represented by (X1)p, it is preferable that the total number of alanine residues is 80% or more (more preferably 85% or more) of the total number of amino acid residues in the polyalanine region. In formula (2), REP1 preferably has two or more consecutive alanine residues, more preferably three or more, even more preferably four or more, and particularly preferably five or more. Furthermore, in REP1 of formula (2), the number of consecutive alanine residues is preferably 20 residues or less, more preferably 16 residues or less, even more preferably 12 residues or less, and particularly preferably 10 residues or less.

[0120] In formula (2), REP2 is an amino acid sequence consisting of 10 to 200 amino acid residues. The total number of glycine, serine, glutamine, proline, and alanine residues contained in this amino acid sequence is preferably 40% or more, more preferably 50% or more, and particularly preferably 60% or more, of the total number of amino acid residues.

[0121] Examples of spider silk proteins derived from the above-mentioned small spindle bookmark silk protein include recombinant spider silk proteins containing the amino acid sequence shown in formula (3) below.

[0122] REP3-REP4-REP5 … Formula (3) [In formula (3), REP3 is an amino acid sequence represented by (Gly-Gly-Z)m, REP4 is an amino acid sequence represented by (Gly-Ala)l, and REP5 is an amino acid sequence represented by (Ala)r. In REP3, Z represents any single amino acid. In REP3, m is between 1 and 4; in REP4, l is between 0 and 4; and in REP5, r is between 1 and 6.

[0123] In REP3, Z represents any single amino acid, but it is particularly preferable that it be a single amino acid selected from the group consisting of Ala, Tyr, and Gln.

[0124] The recombinant spider silk proteins described above (for example, recombinant spider silk proteins containing units of the amino acid sequence shown in formula (2), recombinant spider silk proteins containing the amino acid sequence shown in formula (3), etc.) can be produced using a host transformed with an expression vector containing a gene encoding the native spider silk protein to be recombinant.

[0125] From the viewpoint of piezoelectricity, the elongated organic piezoelectric material 121 preferably contains fibers made of optically active polypeptide (A2). Fibers made from optically active polypeptides (A2) include fibers made from optically active animal proteins. Examples of optically active animal proteins include silk, wool, mohair, cashmere, camel, llama, alpaca, vicuña, angora, spider silk, and the like. From the viewpoint of piezoelectricity, the fiber made of optically active polypeptide (A2) preferably contains at least one of silk and spider silk, and more preferably consists of at least one of silk and spider silk.

[0126] Examples of silk include raw silk, refined silk, recycled silk, and fluorescent silk. As for the silk, raw silk or refined silk is preferred, and polished silk is particularly preferred. Refined silk refers to silk from which sericin has been removed from raw silk, which has a double structure of sericin and fibroin. Refining is the process of removing sericin from raw silk. Raw silk is a dull white color, but by removing sericin from it (i.e., refining), it changes from a dull white to a lustrous silvery-white color. Refining also increases the softness of the silk.

[0127] From the viewpoint of piezoelectricity, the elongated organic piezoelectric material 121 preferably contains long fibers made of optically active polypeptide (A2). This is because, compared to short fibers, the stress applied to the first pressure sensor 10 is more easily transmitted to the piezoelectric material 12 when using long fibers. "Long fiber" refers to a fiber that has a length that allows it to be continuously wound around the first pressure sensor 10 from one end to the other in the longitudinal direction. Silk, wool, mohair, cashmere, camel, llama, alpaca, vicuña, angora, and spider silk are all considered long fibers. Among long fibers, silk and spider silk are preferred from the viewpoint of piezoelectricity.

[0128] If the elongated organic piezoelectric material 121 contains the above-mentioned fibers, it is preferable that the elongated organic piezoelectric material 121 contains at least one thread made of at least one of the above-mentioned fibers. Examples of embodiments in which the elongated organic piezoelectric material 121 includes the above-mentioned thread include an embodiment in which the elongated organic piezoelectric material 121 consists of a single thread, an embodiment in which the elongated organic piezoelectric material 121 is an aggregate of multiple threads, and so on. The above yarn may be twisted or untwisted, but from the viewpoint of piezoelectricity, it is preferable that the yarn has a twist count of 500 T / m or less (i.e., twisted yarn or untwisted yarn (twist count 0 T / m) with a twist count of 500 T / m or less). Examples of untwisted yarn include a single strand of yarn and a collection of multiple strands of yarn.

[0129] (Long organic piezoelectric material) Next, we will provide further explanation regarding the elongated organic piezoelectric material 121.

[0130] <Stabilizer> Preferably, the elongated organic piezoelectric material 121 further contains a stabilizer (B) having a weight-average molecular weight of 200 to 60,000, which has one or more functional groups selected from the group consisting of carbodiimide groups, epoxy groups, and isocyanate groups in one molecule. This can further improve resistance to humidity and heat.

[0131] As stabilizer (B), you may use "stabilizer (B)" as described in paragraphs 0039-0055 of International Publication No. 2013 / 054918.

[0132] Examples of compounds containing a carbodiimide group in one molecule (carbodiimide compounds) that can be used as stabilizers (B) include monocarbodiimide compounds, polycarbodiimide compounds, and cyclic carbodiimide compounds. Suitable monocarbodiimide compounds include dicyclohexylcarbodiimide and bis-2,6-diisopropylphenylcarbodiimide. Furthermore, polycarbodiimide compounds produced by various methods can be used. Those produced by conventional polycarbodiimide production methods (e.g., U.S. Patent No. 2941956, Japanese Patent Publication No. 47-33279, J.Org.Chem. 28, 2069-2075 (1963), Chemical Review 1981, Vol. 81 No. 4, pp. 619-621) can be used. Specifically, the carbodiimide compounds described in Japanese Patent Publication No. 4084953 can also be used. Examples of polycarbodiimide compounds include poly(4,4'-dicyclohexylmethanecarbodiimide), poly(N,N'-di-2,6-diisopropylphenylcarbodiimide), and poly(1,3,5-triisopropylphenylene-2,4-carbodiimide). Cyclic carbodiimide compounds can be synthesized based on methods such as those described in Japanese Patent Publication No. 2011-256337. Commercially available carbodiimide compounds may be used, such as B2756 (trade name) from Tokyo Chemical Industry Co., Ltd., Carbodilite® LA-1 (trade name) from Nisshinbo Chemical Co., Ltd., and Stabaxol P, Stabaxol P400, and Stabaxol I (all trade names) from Rhein Chemie Corporation.

[0133] Compounds containing an isocyanate group in one molecule (isocyanate compounds) that can be used as a stabilizer (B) include 3-(triethoxysilyl)propyl isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylenediisocyanate, p-phenylenediisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and the like.

[0134] Examples of compounds containing an epoxy group in one molecule (epoxy compounds) that can be used as a stabilizer (B) include phenyl glycidyl ether, diethylene glycol diglycidyl ether, bisphenol A-diglycidyl ether, hydrogenated bisphenol A-diglycidyl ether, phenol novolac type epoxy resin, cresol novolac type epoxy resin, and epoxidized polybutadiene.

[0135] As mentioned above, the weight-average molecular weight of stabilizer (B) is between 200 and 60,000, but is more preferably between 200 and 30,000, and even more preferably between 300 and 18,000. If the molecular weight is within the above range, the stabilizer (B) becomes more mobile, and the effect of improving moisture and heat resistance is more effectively achieved. The weight-average molecular weight of stabilizer (B) is particularly preferably between 200 and 900. Note that a weight-average molecular weight of 200 to 900 is approximately equivalent to a number-average molecular weight of 200 to 900. Furthermore, in the case of a weight-average molecular weight of 200 to 900, the molecular weight distribution may be 1.0; in this case, "weight-average molecular weight of 200 to 900" can simply be rephrased as "molecular weight of 200 to 900".

[0136] If the elongated organic piezoelectric material 121 contains a stabilizer (B), the elongated organic piezoelectric material 121 may contain only one type of stabilizer or two or more types. When the elongated organic piezoelectric material 121 contains a stabilizer (B), the content of the stabilizer (B) is preferably 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.01 parts by mass or more and 5 parts by mass or less, even more preferably 0.1 parts by mass or more and 3 parts by mass or less, and particularly preferably 0.5 parts by mass or more and 2 parts by mass or less, per 100 parts by mass of the helical chiral polymer (A1). If the content of stabilizer (B) is 0.01 parts by mass or more, the resistance to humidity and heat is further improved. Furthermore, if the above content is 10 parts by mass or less, the decrease in transparency is further suppressed.

[0137] A preferred embodiment of stabilizer (B) is a combination of stabilizer (B1), which has one or more functional groups selected from the group consisting of carbodiimide groups, epoxy groups, and isocyanate groups, and has a number-average molecular weight of 200 to 900, and stabilizer (B2), which has two or more functional groups selected from the group consisting of carbodiimide groups, epoxy groups, and isocyanate groups in one molecule, and has a weight-average molecular weight of 1000 to 60000. The weight-average molecular weight of stabilizer (B1), which has a number-average molecular weight of 200 to 900, is approximately 200 to 900, and the number-average molecular weight and weight-average molecular weight of stabilizer (B1) are approximately the same. When using stabilizers (B1) and (B2) in combination as stabilizers, it is preferable to include a higher proportion of stabilizer (B1) from the viewpoint of improving transparency. Specifically, from the viewpoint of achieving both transparency and resistance to humidity and heat, it is preferable that the amount of stabilizer (B2) is in the range of 10 parts by mass or more and 150 parts by mass or less per 100 parts by mass of stabilizer (B1), and it is more preferable that it is in the range of 50 parts by mass or more and 100 parts by mass or less.

[0138] The following are specific examples of stabilizer (B) (stabilizers (B-1) to (B-3)).

[0139] [ka]

[0140] The following lists the compound names and commercially available products for the stabilizers (B-1) to (B-3). • Stabilizer (B-1): The compound name is bis-2,6-diisopropylphenylcarbodiimide. Its weight-average molecular weight (equal to "molecular weight" in this example) is 363. Commercially available products include "Stabaxol I" from Rhein Chemie and "B2756" from Tokyo Chemical Industry Co., Ltd. • Stabilizer (B-2)... The compound name is poly(4,4'-dicyclohexylmethanecarbodiimide). A commercially available example with a weight-average molecular weight of approximately 2000 is "Carbodilite (registered trademark) LA-1" manufactured by Nisshinbo Chemical Co., Ltd. • Stabilizer (B-3)... The compound name is poly(1,3,5-triisopropylphenylene-2,4-carbodiimide). A commercially available product is "Stabaxol P" manufactured by Rhein Chemie, with a weight-average molecular weight of approximately 3000. Another example is "Stabaxol P400" manufactured by Rhein Chemie, with a weight-average molecular weight of 20000.

[0141] <Other ingredients> The elongated organic piezoelectric material 121 may contain other components as needed. Other components include known resins such as polyvinylidene fluoride, polyethylene resin, and polystyrene resin; known inorganic fillers such as silica, hydroxyapatite, and montmorillonite; known nucleating agents such as phthalocyanine; and stabilizers other than stabilizer (B). Examples of inorganic fillers and nucleating agents include those listed in paragraphs 0057-0058 of International Publication No. 2013 / 054918.

[0142] (Orientation degree F) As described above, the degree of orientation F of the elongated organic piezoelectric material 121 is 0.5 or more and less than 1.0, but is preferably 0.7 or more and less than 1.0, and more preferably 0.8 or more and less than 1.0. If the orientation degree F of the elongated organic piezoelectric material 121 is 0.5 or higher, there are many helical chiral polymer (A1) molecular chains (e.g., polylactic acid molecular chains) aligned in the stretching direction, resulting in a higher rate of oriented crystal formation and enabling the expression of higher piezoelectric properties. If the orientation degree F of the elongated organic piezoelectric material 121 is less than 1.0, the longitudinal crack strength will be further improved.

[0143] (Degree of crystallinity) The degree of crystallinity of the elongated organic piezoelectric material 121 is a value measured by the X-ray diffraction measurement (wide-angle X-ray diffraction measurement) described above. The degree of crystallinity of the elongated organic piezoelectric material 121 is preferably 20% to 80%, more preferably 25% to 70%, and even more preferably 30% to 60%. A crystallinity of 20% or higher maintains high piezoelectric properties. A crystallinity of 80% or lower maintains high transparency of the elongated organic piezoelectric material 121. Because the degree of crystallinity is 80% or less, for example, when manufacturing the organic piezoelectric film that will be used as the raw material for the long organic piezoelectric material 121 by stretching, whitening and breakage are less likely to occur, making it easier to manufacture the long organic piezoelectric material 121. Also, because the degree of crystallinity is 80% or less, for example, when manufacturing the raw material for the long organic piezoelectric material 121 (e.g., polylactic acid) by melt spinning and then stretching, the resulting fiber has high flexibility and supple properties, making it easier to manufacture the long organic piezoelectric material 121.

[0144] The following describes an example of the operation of the biological information detection device 50. In this embodiment, the bio-information detection device 50 is installed, for example, on a bed 200. A person lies, sits, or gets up on this bio-information detection device 50. In this state, when tension is applied to the bio-information detection device 50 by bio-signals emitted from the person (body movement, periodic vibrations (pulse, respiration, etc.)), polarization occurs in the helical chiral polymer (A1) contained in the pressure sensor, and a potential proportional to the tension is generated. This potential changes over time in accordance with the bio-signals emitted from the person. For example, if the bio-signals emitted from the person are periodic vibrations such as pulse and respiration, the potential generated in the bio-information detection device 50 also changes periodically. The time-dependent change in potential generated by applying tension to the biological information detection device 50 is acquired as a voltage signal by the measurement module. The acquired time-dependent change in potential (voltage signal) is a composite wave of multiple biological signals (pulse wave signal (heart rate signal), respiratory signal, body movement signal). This composite wave is separated by frequency using a Fourier transform to generate separated signals. By performing an inverse Fourier transform on each of the generated separated signals, the biological signals corresponding to each separated signal are obtained.

[0145] For example, if the biosignal emitted from the subject is a composite wave of heart rate signals and respiratory signals, the potential generated when tension is applied to the biosignal detection device 50 changes periodically over time. Generally, a person's pulse is between 50 and 100 beats per minute, with a period of between 0.83 Hz and 1.67 Hz. Also, generally, a person's respiration is between 12 and 20 breaths per minute, with a period of between 0.20 Hz and 0.33 Hz. Furthermore, generally, a person's body movement is above 10 Hz. Based on these guidelines, it is possible to separate the composite wave of multiple biological signals into their individual components. Furthermore, it is possible to obtain a velocity pulse wave signal from the heart rate signal. The separation of a composite wave of multiple biological signals into their respective biological signals is performed, for example, using a biological signal notification program, through Fourier transforms and inverse Fourier transforms.

[0146] In this way, the combined wave of multiple biological signals can be separated into each of the multiple biological signals.

[0147] Furthermore, biosignal data may be generated based on at least one of the biosignals separated as described above. The biosignal data is not particularly limited, as long as it is calculated based on biosignals. Examples of biosignal data include the number of biosignals per unit time and the average value of past biosignal counts.

[0148] (Detection result) Next, an example of the detection results when using the biological information detection device 50 of this embodiment will be described using Figure 7. A bed device 100 with the thread member 38 installed as a modified example of the sensor unit 32 shown in Figure 2C was used as the embodiment, and a bed device without the thread member 38 was used as the comparative example, and the detection state when a person is lying on the bed 200 was compared.

[0149] As shown in Figure 7, the detection results are represented by a line graph with voltage on the vertical axis and time on the horizontal axis. Line graph G1 shows the detection results of an embodiment where the thread member 38 is installed. Line graph G2 shows the detection results of a comparative example where the thread member 38 is not installed. Each line graph contains voltage changes of two different periods (i.e., up and down movements of the line graph). Here, the voltage changes with relatively long periods (for example, about one up and down movement from 5 seconds to 9 seconds in line graph G1) are the detection results due to the breathing of a person lying in bed 200.

[0150] In the embodiment, the maximum detected voltage was "0.11647" and the minimum was "-0.10785". Therefore, the squared error between the maximum and minimum voltage values ​​in the embodiment is calculated to be "0.045590". In the comparative example, the maximum detected voltage was "0.065988" and the minimum was "-0.051214". Therefore, the squared error between the maximum and minimum voltage values ​​in the comparative example is calculated to be "0.018070". In other words, comparing the squared voltage error in the embodiment with that of the comparative example, there is a difference of approximately 2.5 times, indicating that the detection accuracy is improved when the thread member 38 is installed.

[0151] (Summary of the first embodiment) The first embodiment of the bio-information detection device 50 comprises a first pressure sensor 10 and a thread member 38 that supports the first pressure sensor 10. Therefore, according to the bio-information detection device 50 of this embodiment, the sensor sensitivity can be improved by providing a location that makes it easier for stress strain to occur in the first pressure sensor 10, which acts as a piezoelectric sensor.

[0152] In the first embodiment of the bio-information detection device 50, the first pressure sensor 10 is supported by a thread member 38 separate from the protective sheet 37A. Therefore, according to the bio-information detection device 50 of this embodiment, the signal strength detected by the bio-information detection device 50 can be adjusted by adjusting the number of thread members 38. For example, by increasing the number of thread members 38, the number of points where space S is formed can be increased. As the number of points where space S is formed increases, the amount of strain due to deformation of the first pressure sensor 10 increases, and thus the signal strength detected by the bio-information detection device 50 can be amplified.

[0153] The biometric information detection device 50 of the first embodiment is positioned in the upper body area of ​​the bed 200 on which a person lies, along the width direction of the bed 200. Therefore, according to the biometric information detection device 50 of this embodiment, biometric information such as heart rate and respiratory rate of the person can be detected on the bed 200.

[0154] [Second Embodiment] In the second embodiment, a case in which the sensor unit 32 is provided with a second pressure sensor 20 will be described. The differences from the first embodiment will be described below. Note that the other configurations are the same as in the embodiments described above, and a detailed explanation will be omitted.

[0155] (Sensor unit configuration) Figure 8A is a plan view of the sensor unit 32 according to the second embodiment, as seen from above. Figure 8B is a diagram showing the layer configuration of the sensor unit 32, based on the cross-sectional view along line AA shown in Figure 8A. Note that Figure 8A shows the sensor unit with the protective sheet 37C, which will be described later, removed.

[0156] As shown in Figure 8A, the sensor unit 32 comprises a protective sheet 37A, a protective sheet 37C (see Figure 8B), a support plate 36B, a plurality of thread members 38, a first pressure sensor 10, a cushioning material 22, a second pressure sensor 20, and a plurality of coaxial cables 110. The protective sheet 37A is the part that is placed directly on the floor plate 220. As shown in Figure 8B, the support plate 36B is installed on top of the protective sheet 37A. The plurality of thread members 38 and the cushioning material 22 are installed on top of the support plate 36B. The first pressure sensor 10 is installed on top of the support plate 36B and on top of each thread member 38 on the upper surface of the support plate 36B. The second pressure sensor 20 is installed along the top of the cushioning material 22. The protective sheet 37C is installed on top of the support plate 36B and on top of the first pressure sensor 10 and the second pressure sensor 20 on the upper surface of the support plate 36B. Furthermore, multiple coaxial cables 110 are electrically connected to the first pressure sensor 10 and the second pressure sensor, respectively. Each component is bonded to the others using double-sided tape and adhesive. In addition, as shown in Figure 8A, in the area where the first pressure sensor 10 protrudes without following the thread member 38, a space S is formed on both sides of the thread member 38. The support plate 36B is an example of a "base material". Note that the protective sheet 37A, protective sheet 37C, support plate 36B, first pressure sensor 10 and thread member 38 are the same as those shown in Figure 2C, so a detailed explanation is omitted.

[0157] The cushioning material 22 shown in Figure 8A is a sponge sheet installed in the center of the sensor unit 32 and has a convex structure to effectively transmit the pressure applied to the second pressure sensor. The cushioning material 22 in this embodiment has a density of 0.05 to 0.5 kg / m³. 3Furthermore, the hardness of the Asker C type as specified in JIS K7312 is in the range of 5 to 60. Suitable materials for the cushioning material 22 include foamed rubber and foamed resin materials. Examples of foamed resin materials include soft polyurethane foam, rigid polyurethane foam, polystyrene foam, polyethylene foam, polypropylene foam, EVA cross-linked foam, PET resin foam, phenolic foam, silicone foam, polyvinyl chloride foam, urea foam, acrylic foam, polyimide foam, and EPDM foam. As an example, the cushioning material 22 can be set to a length of 500 mm, a width of 10 mm, and a thickness of 2 mm.

[0158] The second pressure sensor 20 is a sheet-shaped sensor that detects the pressure exerted by a person lying on the mattress 230. The second pressure sensor 20 can be any pressure sensor that detects pressure exerted by a person, and it is sufficient if it can detect air pressure or resistance pressure. Specifically, the second pressure sensor 20 is a so-called resistive pressure sensor in which the resistance value changes when pressure is applied to the second pressure sensor 20, and the output voltage changes in accordance with the change in resistance value. For example, the SF15-600 manufactured by LEANSTAR and the FSR (Force Sensing Resistor)-408 manufactured by Interlink Electronics, Inc. are suitably used. Furthermore, the second pressure sensor 20 is a sensor capable of detecting steady-state pressure. The second pressure sensor 20 is electrically connected to the information processing unit 40 via a coaxial cable 110 as wiring. Here, the second pressure sensor 20 is an example of a "second sensor".

[0159] In the second embodiment, each of the two linear sensors of the first pressure sensor 10 and the second pressure sensor 20 extends in the direction D1. That is, the two linear sensors of the first pressure sensor 10 and the second pressure sensor 20 are arranged parallel to each other. Here, parallel includes a nearly parallel state in which the two linear sensors of the first pressure sensor 10 and the second pressure sensor 20 appear to be parallel at first glance. Specifically, nearly parallel means that the angle between the two linear sensors of the first pressure sensor 10 and the second pressure sensor 20 is less than 10 degrees.

[0160] (Information Processing Unit) As shown in Figure 9, the information processing unit 40 of the second embodiment (see Figure 1) includes an AD converter 42 that converts the voltage output, which is an analog signal output from the second pressure sensor 20 through a voltage conversion circuit 44 and an amplifier circuit 43, into a digital signal, and a processing PC 50 that detects the digital signal from the second pressure sensor 20. The AD converter 42 is provided with multiple input terminals for inputting analog signals, and the second pressure sensor 20 is electrically connected to one of these input terminals.

[0161] (Functional Configuration) The detection unit 55 (see Figure 4) of the second embodiment has the function of detecting digital signals related to the first pressure sensor 10 and the second pressure sensor 20 output from the AD converter 42 via the communication I / F 41E.

[0162] The determination unit 56 (see Figure 4) has the function of determining whether a person is lying down on the bed 200 or sitting up, based on the detection results of the first pressure sensor 10 and the second pressure sensor 20 detected by the detection unit 55. For example, if the voltage output of the first pressure sensor 10 fluctuates beyond a predetermined threshold, the determination unit 56 determines whether the person has transitioned from lying down to sitting up, or from sitting up to lying down.

[0163] In this embodiment, the determination unit 56 can first determine whether the person is out of bed or sitting up based on the detection result of the first pressure sensor 10. That is, the determination unit 56 can determine the transition from a sleeping state to a sitting state by detecting a change in the voltage output of the first pressure sensor 10 that exceeds a threshold. Then, the determination unit 56 can determine that the person has transitioned from a sleeping state to a sitting state by detecting an increase in the voltage output of the second pressure sensor 20 that exceeds a threshold, and that the person is maintaining a sitting state by continuing to detect the increased voltage output. In this example, the determination unit 56 can determine that the person has transitioned from a sleeping state to a sitting state based on the detection result of the first pressure sensor 10 and the detection result of the second pressure sensor 20.

[0164] In other words, whether the human body is in an upright or sleeping state is ultimately determined after waiting for the detection result of the second pressure sensor 20, but since the detection by the first pressure sensor 10 is earlier than that of the second pressure sensor, the initial determination is made based on the detection result of the first pressure sensor 10.

[0165] (Summary of the second embodiment) This embodiment has the same effects as the first embodiment. Furthermore, this embodiment has the following additional effects due to the inclusion of the second pressure sensor 20. Specifically, by performing bed exit determination based on the detection results of both the first pressure sensor 10 and the second pressure sensor 20, as in this embodiment, reliable bed exit determination becomes possible. For example, the second pressure sensor 20, which is a resistance-type pressure sensor, cannot distinguish whether the pressure is being applied to a human body or an object. That is, the second pressure sensor 20 cannot distinguish between placing luggage on the bed 200 and a human body lying down. Also, the second pressure sensor 20 cannot distinguish between removing luggage from the bed 200 and a human body getting out of bed. Therefore, by combining the detection results of the second pressure sensor 20 with the pulse wave signal and respiratory signal detection results obtained from the first pressure sensor 10, which is a biosensor, reliable bed exit detection for a human body becomes possible.

[0166] <Other Embodiments> Next, several embodiments in which the thread member 38 supporting the first pressure sensor 10 is formed integrally with the support plate 36B will be described using Figures 10A to 15B. Figures 10A, 11A, 12A, 13A, 14A, and 15A show schematic plan views of the first pressure sensor 10 and support plate 36B of each embodiment as seen from above. Figures 10B, 11B, 12B, 13B, 14B, and 15B show schematic side cross-sectional views of the first pressure sensor 10 and support plate 36B of each embodiment as seen from the side. Each figure shows only a part of the sensor unit 32 in order to explain the configuration in which the first pressure sensor 10 of each embodiment is installed on the upper part of the support plate 36B.

[0167] [Third Embodiment] As shown in Figures 10A and 10B, the support plate 36B of the third embodiment has protrusions T that correspond to a plurality of thread members 38 that are repeatedly arranged along the longitudinal direction of the first pressure sensor 10. In Figures 10A and 10B, only the leftmost protrusion T (i.e., the left edge of the paper) of the plurality of protrusions T is referenced. As shown in the plan view of Figure 10A and the side cross-sectional view of Figure 10B, the first pressure sensor 10 is supported by the plurality of protrusions T of the support plate 36B. Also, as shown in the side cross-sectional view of Figure 10B, the first pressure sensor 10 is installed so as to pass over the space formed between the plurality of protrusions T. In other words, there are no support parts that directly support the first pressure sensor 10 between adjacent protrusions T. Therefore, when pressure from a person lying on the bed 200 is applied to the first pressure sensor 10, greater strain occurs in the first pressure sensor 10 between adjacent protrusions T compared to the portion supported by the protrusions T of the support plate 36B of the first pressure sensor 10. In other words, the bio-information detection device 50 can detect the pressure from a person lying on the bed 200 from the voltage output caused by the strain of the first pressure sensor 10 between adjacent protrusions T.

[0168] [Fourth Embodiment] As shown in Figures 11A and 11B, the fourth embodiment includes an elastic member 39 that supports the first pressure sensor 10. In Figures 11A and 11B, only the leftmost elastic member 39 (i.e., the leftmost elastic member 39 on the page) is reference numerald. The support plate 36B has the same shape as in the third embodiment, so a detailed description is omitted. As shown in the plan view of Figure 11A and the side cross-sectional view of Figure 11B, the first pressure sensor 10 is supported by a plurality of protrusions T and a plurality of elastic members 39 on the support plate 36B. As shown in the side cross-sectional view of Figure 11B, the elastic member 39 is formed between the plurality of protrusions T. A gap may be provided between the protrusions T and the elastic member 39. Here, the elastic member 39 is made of a material having a lower modulus of elasticity compared to the support plate 36B. As specific materials for the elastic member 39, foamed rubber and foamed resin materials are preferably used. As foam resin materials, materials such as flexible polyurethane foam, rigid polyurethane foam, polystyrene foam, polyethylene foam, polypropylene foam, EVA crosslinked foam, PET resin foam, phenol foam, silicone foam, polyvinyl chloride foam, urea foam, acrylic foam, polyimide foam, and EPDM foam can be used. In other words, in the part supported by the elastic member 39, the first pressure sensor 10 deforms according to the pressure applied to the first pressure sensor 10 and the elastic modulus of the elastic member 39. Therefore, when pressure from a person lying on the bed 200 is applied to the first pressure sensor 10, greater strain occurs in the part supported by the elastic member 39 compared to the part supported by the support plate 36B of the first pressure sensor 10. That is, the bio-information detection device 50 can detect the pressure from a person lying on the bed 200 from the voltage output caused by the strain of the first pressure sensor 10 that occurs in the part supported by the elastic member 39. Furthermore, since there is no space between the multiple protrusions T, the degree of strain on the portion of the first pressure sensor 10 supported by the elastic member 39 is reduced compared to the third embodiment. As a result, the durability of the portion of the first pressure sensor 10 supported by the elastic member 39 is improved, and it can withstand larger loads.Furthermore, it can suppress extraneous vibrations that would otherwise cause noise during the detection of biological information.

[0169] [Fifth Embodiment] As shown in Figures 12A and 12B, the fifth embodiment is provided with a sheet-like elastic member 39 that supports the first pressure sensor 10. Since the support plate 36B has the same shape as in the third embodiment and the elastic member 39 has the same properties as in the fourth embodiment, a detailed explanation is omitted. As shown in the plan view of Figure 12A and the side cross-sectional view of Figure 12B, the first pressure sensor 10 is supported by a plurality of protrusions T on the support plate 36B via the sheet-like elastic member 39. Furthermore, as shown in the side cross-sectional view of Figure 12B, the sheet-like elastic member 39 is installed between the first pressure sensor 10 and the plurality of protrusions T. In other words, the entire first pressure sensor 10 is supported by the sheet-like elastic member 39. Therefore, when pressure from a person lying on the bed 200 is applied to the first pressure sensor 10, the degree of distortion of the first pressure sensor 10 between adjacent protrusions T can be mitigated compared to the third embodiment. In other words, the durability of the first pressure sensor 10 between adjacent protrusions T is improved, allowing it to withstand larger loads. Furthermore, since the entire first pressure sensor 10 is supported by the elastic member 39, extraneous vibrations that cause noise during the detection of biological information can be suppressed more effectively compared to the fourth embodiment.

[0170] [Sixth Embodiment] As shown in Figures 13A and 13B, the support plate 36B of the sixth embodiment is provided with a plurality of circular holes repeatedly arranged along the longitudinal direction of the first pressure sensor 10. As shown in the plan view of Figure 13A and the side cross-sectional view of Figure 13B, the first pressure sensor 10 is supported by the support plate 36B. Furthermore, the first pressure sensor 10 is installed so as to pass over the plurality of holes provided in the support plate 36B. In other words, there is no support part that directly supports the first pressure sensor 10 in the part that passes over the circular holes. Therefore, when pressure from a person lying on the bed 200 is applied to the first pressure sensor 10, a larger strain occurs in the part that passes over the circular holes compared to the part of the first pressure sensor 10 that is supported by the support plate 36B. That is, the bio-information detection device 50 can detect the pressure from a person lying on the bed 200 from the voltage output caused by the strain of the first pressure sensor 10 that occurs in the part that passes over the circular holes. Note that the circular hole is just one example of a hole provided in the support plate 36B; the hole may be of any shape, such as a triangle or square, and may not be a through hole. Furthermore, in the sixth to eighth embodiments, the support plate 36B itself constitutes the support portion.

[0171] [Seventh Embodiment] As shown in Figures 14A and 14B, the seventh embodiment includes an elastic member 39 that supports the first pressure sensor 10. In Figures 14A and 14B, only one of the multiple elastic members 39 (i.e., the second elastic member 39 from the left edge of the page) is labeled with a reference numeral. The support plate 36B has the same shape as in the sixth embodiment, and the elastic member 39 has the same properties as in the fourth embodiment, so a detailed explanation is omitted. As shown in the plan view of Figure 14A and the side cross-sectional view of Figure 14B, the first pressure sensor 10 is supported by the support plate 36B and the multiple elastic members 39. As shown in the side cross-sectional view of Figure 14B, the elastic member 39 is formed in a circular hole provided in the support plate 36B. A gap may be provided between the support plate 36B and the elastic member 39. In other words, in the portion supported by the elastic member 39, the first pressure sensor 10 deforms according to the pressure applied to the first pressure sensor 10 and the elastic modulus of the elastic member 39. Therefore, when pressure from a person lying on the bed 200 is applied to the first pressure sensor 10, greater strain occurs in the portion supported by the elastic member 39 compared to the portion supported by the support plate 36B of the first pressure sensor 10. That is, the bio-information detection device 50 can detect the pressure from a person lying on the bed 200 as a voltage output due to the strain of the first pressure sensor 10 that occurs in the portion supported by the elastic member 39. Furthermore, since there is no space in the circular hole, the degree of strain in the portion of the first pressure sensor 10 supported by the elastic member 39 is mitigated compared to the sixth embodiment. Therefore, the durability of the first pressure sensor 10 in the portion supported by the elastic member 39 is improved, and it can withstand larger loads. In addition, extraneous vibrations that become noise during bio-information detection can be suppressed.

[0172] [Eighth Embodiment] As shown in Figures 15A and 15B, in the eighth embodiment, a sheet-like elastic member 39 is provided to support the first pressure sensor 10. Since the support plate 36B has the same shape as in the sixth embodiment and the elastic member 39 has the same properties as in the fourth embodiment, a detailed explanation is omitted. As shown in the plan view of Figure 15A and the side cross-sectional view of Figure 15B, the first pressure sensor 10 is supported by the support plate 36B via the sheet-like elastic member 39. Furthermore, as shown in the side cross-sectional view of Figure 15B, the sheet-like elastic member 39 is installed between the first pressure sensor 10 and the support plate 36B. In other words, the entire first pressure sensor 10 is supported by the sheet-like elastic member 39. Therefore, when pressure from a person lying on the bed 200 is applied to the first pressure sensor 10, the degree of distortion of the first pressure sensor 10 that occurs in the portion passing over the circular hole in the support plate 36B can be mitigated compared to the sixth embodiment. In other words, the durability of the first pressure sensor 10 in the portion passing over the circular hole is improved, allowing it to withstand larger loads. Furthermore, since the entire first pressure sensor 10 is supported by the elastic member 39, extraneous vibrations that cause noise during the detection of biological information can be suppressed more effectively compared to the seventh embodiment.

[0173] (others) The bed device 100 may be a so-called electric bed that uses electricity as a power source and whose main function is to change the angle of the bed base 220 in the upper body area. The bed device 100 may also be equipped with a sensor that can detect the angle of the bed base 220, more specifically, the angle of the bed base 220 in the upper body area, such as an acceleration sensor. In other words, if the angle of the upper body area is different, the pressure applied to the pressure sensor may also fluctuate, making it possible to reliably detect when the patient leaves the bed even if the angle changes. Furthermore, by combining the biological information obtained from the first pressure sensor 10, which is a biosensor, with the angle information obtained from the acceleration sensor, it becomes possible to detect changes in load and biological information due to the bed angle. As a result, it becomes possible to calculate the optimal sleep onset angle and breathing angle, and to propose these optimal sleep onset angles and breathing angles to the user of the bed device 100.

[0174] Furthermore, in the second embodiment described above, the first pressure sensor 10 and the second pressure sensor 20 were configured as an integrated sensor unit 32, but the system is not limited to this. For example, the first pressure sensor 10 and the second pressure sensor 20 may be configured as separate sensor units, arranged parallel to each other on the upper surface of the floor plate 220, to detect pressure at other parts of the human body.

[0175] The biometric information detection device 50 of this embodiment may be incorporated into an existing bed 200 to form a bed device 100, or it may be installed and used on a carpet, flooring, tatami mat, etc. The biometric information detection device 50 installed on a carpet, flooring, tatami mat, etc. will have the same effects as the bed device 100 described above. With the biometric information detection device 50 of this embodiment, since it can be combined with existing bedding, the existing bedding can be used as is, and deterioration of sleeping comfort can be suppressed.

[0176] In the bed device 100 of this embodiment, as the foaming ratio of the elastic member 39, which is foamed rubber or resin, increases, the variation in density and rubber hardness increases, and the variation in the sensor sensitivity of the first pressure sensor 10 increases. Furthermore, materials such as natural rubber have a large change in rubber hardness over time, resulting in a large variation in sensor sensitivity. Materials such as EPDM foam, which have little change over time, are preferable.

[0177] In addition, the processing related to the detection unit 55, determination unit 56, and notification unit 57, which the CPU 41A reads and executes in the above embodiment, may be executed by various processors other than the CPU. Examples of such processors include PLDs (Programmable Logic Devices) such as FPGAs (Field-Programmable Gate Arrays) whose circuit configuration can be changed after manufacturing, and dedicated electrical circuits that are processors with circuit configurations specifically designed to execute specific processing, such as ASICs (Application Specific Integrated Circuits). Furthermore, the various processing may be executed by one of these various processors, or by a combination of two or more processors of the same or different types (for example, multiple FPGAs, and a combination of a CPU and an FPGA). More specifically, the hardware structure of these various processors is an electrical circuit that combines circuit elements such as semiconductor elements.

[0178] Furthermore, although the above embodiment describes a configuration in which the executable program is pre-stored (installed) in storage 41D, the invention is not limited to this configuration. Each program may be provided in a form recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory), or USB (Universal Serial Bus) memory. Alternatively, the program may be provided in a form that is downloaded from an external device via a network. The technology disclosed herein is also applicable to programs and program products.

[0179] Furthermore, the following additional information is disclosed regarding one embodiment of the technology disclosed in this application as described above.

[0180] (Note 1) A linear first sensor that detects radial pressure applied from a living organism, Supports are repeatedly arranged along the longitudinal direction of the first sensor and support the first sensor, A biological information detection device equipped with the following features.

[0181] (Note 2) The support portion is integrally formed with the substrate that supports the first sensor. The biological information detection device described in Appendix 1.

[0182] (Note 3) The support portion is configured separately from the substrate that supports the first sensor. A biological information detection device as described in Appendix 1 or Appendix 2.

[0183] (Note 4) The system includes elastic members that alternately support the first sensor with the support portion. A biological information detection device as described in any one of the appendices 1 to 3.

[0184] (Note 5) The support portion supports the first sensor via an elastic member. A biological information detection device as described in any one of the appendices 1 through 4.

[0185] (Note 6) The above first recovery is, It comprises a long conductor and a long, flat piezoelectric material made of an optically active helical chiral polymer, wound around the outer circumference of the conductor. Polarization occurs in the radial direction in response to axial stress. A biological information detection device as described in any one of the appendices 1 through 5.

[0186] (Note 7) The aforementioned helical chiral polymer is polylactic acid. The biological information detection device described in Appendix 6.

[0187] (Note 8) The above first recovery is, Piezoelectric constant d 14This is a long organic piezoelectric material containing an organic piezoelectric material having the following properties: A biological information detection device as described in any one of the appendices 1 through 7.

[0188] (Note 9) The first sensor is provided on the support that supports the living organism, A biological information detection device as described in any one of the appendices 1 through 8.

[0189] (Note 10) The support is a bed on which the living organism sleeps, The first sensor is positioned at least in the upper body area when the living body is lying on the bed. The biological information detection device described in Appendix 9.

[0190] (Note 11) The support is a bed on which the living organism sleeps, The first sensor is arranged along the width direction of the bed, A biological information detection device as described in Appendix 9 or Appendix 10.

[0191] (Note 12) The support is equipped with a second resistive sensor that detects pressure received from the living body, which is supported by the support. A biological information detection device as described in any one of the appendices 9 through 11.

[0192] (Note 13) The first sensor and the second sensor are arranged parallel to each other. A biological information detection device as described in Appendix 12.

[0193] (Note 14) The first sensor and the second sensor are provided in the support along the pressure-receiving surface that receives pressure from the living body, The second sensor is mounted on a substrate supporting the first sensor. A biological information detection device as described in Appendix 12 or Appendix 13. [Explanation of Symbols]

[0194] 10 First pressure sensor 20 Second pressure sensor 32 Sensor unit 36B Support plate 37A Protective sheet 38 Thread member T Projection 39 Elastic member 11 Internal conductor 12 Piezoelectric body 121 Long organic piezoelectric body 13 External conductor 50 Biosignal detection device 200 Bed

Claims

1. A linear first sensor that detects radial pressure applied from a living organism, Supports are repeatedly arranged along the longitudinal direction of the first sensor and support the first sensor, A biological information detection device equipped with the following features.

2. The support portion is integrally formed with the substrate that supports the first sensor. A biological information detection device according to claim 1.

3. The support portion is configured separately from the substrate that supports the first retrieval. A biological information detection device according to claim 1.

4. The system includes elastic members that alternately support the first sensor with the support portion. A biological information detection device according to claim 1.

5. The support portion supports the first sensor via an elastic member. A biological information detection device according to claim 1.

6. The first recovery described above is It comprises a long conductor and a long, flat piezoelectric material made of an optically active helical chiral polymer, wound around the outer circumference of the conductor. Polarization occurs in the radial direction in response to axial stress. A biological information detection device according to claim 1.

7. The aforementioned helical chiral polymer is polylactic acid. The biological information detection device according to claim 6.

8. The first recovery described above is Piezoelectric constant d １４ This is a long organic piezoelectric material containing an organic piezoelectric material having the following properties: The biological information detection device according to claim 6.

9. The first sensor is provided on the support that supports the living organism, A biological information detection device according to any one of claims 1 to 8.

10. The support is a bed on which the living organism sleeps, The first sensor is positioned at least in the upper body area when the living body is lying on the bed. A biological information detection device according to claim 9.

11. The support is a bed on which the living organism sleeps, The first sensor is arranged along the width direction of the bed, A biological information detection device according to claim 9.

12. The support is equipped with a second resistive sensor that detects pressure received from the living body, which is supported by the support. A biological information detection device according to claim 9.

13. The first sensor and the second sensor are arranged parallel to each other. The biological information detection device according to claim 12.

14. The first sensor and the second sensor are provided in the support along the pressure-receiving surface that receives pressure from the living body, The second sensor is installed on a substrate supporting the first sensor. The biological information detection device according to claim 12.

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