Detection device and detection system

Abstract

This detection device comprises: an optical sensor; a detection circuit for measuring a photocurrent output from the optical sensor; and a storage circuit for storing pulse wave data of a subject acquired by the detection circuit. The detection device calculates a pulse wave interval on the basis of pulse wave data corresponding to a specific period of time out of the stored pulse wave data, stores the pulse wave interval in the storage circuit, and outputs the stored pulse wave interval. This detection system comprises: the detection device; and a server device on a cloud to which pulse wave interval data, which is information on the pulse wave interval, is transmitted from the detection device via a host. The server device on the cloud executes fast Fourier transform (FFT) calculation using the pulse wave interval data, integrates values over a predetermined frequency range, and stores the integration result as vital signs data.

Description

Detection device and detection system

[0001] The present invention relates to a detection device and a detection system.

[0002] Optical sensors capable of detecting fingerprint patterns and vein patterns are known (see, for example, Patent Literature 1). Such optical sensors are incorporated into wearable devices such as smartwatches, wristwatches, and wristbands, and are used to acquire biometric information such as pulse waves.

[0003] Non-Patent Documents 1 to 3 disclose that evaluation, analysis, etc. of autonomic nervous function is performed by using the pulse wave interval (RRI) obtained through a pulse wave acquired as biological information.

[0004] Japanese Patent Application Laid-Open No. 2009-32005

[0005] Koichi Fujiwara, "Heart Rate Variability Analysis for Health Monitoring," Systems, Control, and Information, Vol. 61, No. 9; Yoshiaki Matsumoto, Nobuaki Mori, Ryo Mitajiri, and Zhongwei Jiang, "Research on Mental Stress Assessment Methods Using Heart Rate Variability," Life Support, Vol. 22, No. 3, 2010; Yuka Maeda, Masaki Sekine, Toshiyo Tamura, and Koichi Mizutani, "Verification of Pulse Wave Propagation Time Variability for Autonomic Nervous System Estimation Using Pulse Waves," Biomedical Engineering, 54(6): 261-266, 2016

[0006] In such a detection device using an optical sensor, no consideration is given to obtaining pulse wave interval (RRI) as biological information.

[0007] An object of the present invention is to provide a detection device and a detection system capable of acquiring pulse wave interval (RRI) as biological information.

[0008] A detection device of one aspect of the present disclosure includes an optical sensor, a detection circuit that measures the photocurrent output from the optical sensor, and a memory circuit that stores pulse wave data of a detected body acquired by the detection circuit, calculates a pulse wave interval based on pulse wave data corresponding to a predetermined period of time from the pulse wave data, stores the pulse wave interval in the memory circuit, and outputs the stored pulse wave interval.

[0009] A detection system according to one aspect of the present disclosure includes the detection device described above and a cloud-based server device to which pulse interval data, which is information relating to the pulse interval, is transmitted from the detection device via a host, and the cloud-based server device performs a fast Fourier transform (FFT) calculation using the pulse interval data, integrates a predetermined frequency range, and stores the result as vital data.

[0010] FIG. 1 is a schematic diagram illustrating an example of the appearance of a detection device according to an embodiment, when a finger is placed inside the detection device, as viewed from the side of the housing. FIG. 2 is a cross-sectional view taken along II-II' in FIG. 1. FIG. 3 is a cross-sectional view taken along III-III' in FIG. 2. FIG. 4 is a development view illustrating an example of a development of a flexible substrate of the detection device according to an embodiment. FIG. 5 is a schematic top view illustrating an example of the configuration of the substrate shown in FIG. 4. FIG. 6 is a cross-sectional view taken along VI-VI' in FIG. 5. FIG. 7 is a block diagram illustrating an example of the configuration of a detection device according to an embodiment. FIG. 8 is a circuit diagram illustrating an example of the configuration of a detection device according to an embodiment. FIG. 9 is a block diagram illustrating an example of the configuration of a detection system including a detection device according to an embodiment. FIG. 10 is a flowchart illustrating a method for measuring the RRI, the average value of the RRI, and the standard deviation of the RRI in the detection device according to an embodiment. FIG. 11 is a flowchart illustrating a method for analyzing the frequency of the RRI in the detection device and detection system according to an embodiment. FIG. 12 is an explanatory diagram illustrating the pulse wave and RRI measured in the detection device. FIG. 13 is a graph schematically illustrating the relationship between the RRI and time. FIG. 14 is an explanatory diagram for explaining another example of a method for measuring RRI and a method for calculating the average value and standard deviation of RRI.

[0011] Modes (embodiments) for carrying out the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Note that the disclosure is merely an example, and any appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the present disclosure are naturally included within the scope of the present disclosure. Furthermore, for clarity of explanation, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present disclosure. Furthermore, in this disclosure and each figure, elements similar to those described above with reference to the previous figures may be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0012] In the present disclosure, when expressing an aspect of placing another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both a case in which another structure is placed directly on top of a certain structure so as to be in contact with the certain structure, and a case in which another structure is placed above a certain structure via yet another structure.

[0013] (Embodiment) Fig. 1 is a schematic diagram showing an example of the appearance of a detection device according to an embodiment when a finger is placed inside the detection device as viewed from the side of the housing. Fig. 2 is a cross-sectional view taken along line II-II' in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III' in Fig. 2.

[0014] As shown in FIG. 1 , the detection device 1 according to the embodiment is a ring-shaped device that can be attached to and detached from the human body. The detection device 1 is worn on a finger Fg of the human body. The finger Fg includes the thumb, index finger, middle finger, ring finger, little finger, etc. The human body is an individual to be authenticated, whose identity is verified by the detection device 1. The detection device 1 can detect biometric information about a living organism from the finger Fg on which it is worn. The finger Fg is an example of a measurement target. The measurement target is a living organism or a part of a living organism, and is a measurement target. The detection device 1 is made into a ring or wristband, making it easy for the user to carry. In the following description, it is assumed that the detection device 1 is used as a ring.

[0015] Although the detection device 1 is a ring-shaped device, the invention is not limited to this, and the detection device 1 may be built into a wristwatch or a wristband to be configured as a wearable device.

[0016] 2, the detection device 1 includes a housing 200, a protective member 210, a light source 60, a plurality of optical sensors PD1, PD2, PD3, and PD4, and a flexible printed circuit board 70. The detection device 1 further includes a battery 80, a battery-powered circuit 81, a coil 82, a light source drive circuit 101, a temperature sensor 83, a motion sensor 84, an antenna-integrated communication device 103, and a control circuit 50, which are provided inside the housing 200. A detailed configuration example of the battery 80, the battery-powered circuit 81, the coil 82, the light source drive circuit 101, the temperature sensor 83, the motion sensor 84, the antenna-integrated communication device 103, and the control circuit 50 will be described later with reference to FIG.

[0017] In the following description, when it is not necessary to distinguish between the multiple optical sensors PD1, PD2, PD3, and PD4, they will simply be referred to as optical sensors PD.

[0018] The housing 200 is formed in a ring shape (annular shape) that can be worn on a finger Fg, and is a wearable member that is worn on a living body. As shown in FIG. 3 , the cross-sectional shape of the housing 200 is concave, and the light source 60, multiple optical sensors PD, a flexible printed circuit board 70, and the like are housed inside the housing 200. The flexible printed circuit board 70 is housed inside the housing 200, for example, by forming the housing 200 in a ring shape using a mold and filling the surrounding area with a filler material. The housing 200 is formed in a ring shape using a material such as metal or non-transparent synthetic resin. However, the housing 200 may also be constructed by combining multiple materials, such as a transparent resin material and a metal material.

[0019] The protective member 210 covers the light source 60, the multiple optical sensors PD, the flexible printed circuit board 70, etc., and is disposed in an opening on the inner peripheral surface side of the housing 200. The protective member 210 is formed in a ring shape from a housing material such as a transparent synthetic resin or silicone.

[0020] FIG. 4 is a development view showing an example of a development of a flexible substrate of a detection device according to an embodiment. As shown in FIG. 4 , the flexible printed circuit board 70 is formed in a deformable band shape, and is formed into a ring shape by connecting one end 71 and the other end 72. The flexible printed circuit board 70 has a first mounting area 73 and a second mounting area 74. The first mounting area 73 is an area where the light source 60 and the like are mounted. The second mounting area 74 is an area where the control circuit 50, the battery 80, and the like are mounted. Note that in FIG. 4 , various drive circuits, sensors, and the like mounted on the flexible printed circuit board 70 shown in FIG. 2 are omitted from the illustration.

[0021] The substrate 21 is mounted on the flexible printed circuit board 70 so as to straddle the vicinity of the light source 60 in the first mounting region 73. The substrate 21 is a sensor substrate on which a plurality of optical sensors PD and the like are mounted. The substrate 21 is an insulating substrate, and is formed, for example, in a strip shape using a film-like resin or the like, making it a deformable substrate. The flexible printed circuit board 70 electrically connects the light source 60 and the plurality of optical sensors PD on the substrate 21 to the control circuit 50.

[0022] In the following description, the first direction Dx is a direction in a plane parallel to the substrate 21. The second direction Dy is a direction in a plane parallel to the substrate 21, and is a direction perpendicular to the first direction Dx. The second direction Dy may intersect the first direction Dx without being perpendicular to it. The third direction Dz is a direction perpendicular to the first direction Dx and the second direction Dy. The third direction Dz is the normal direction of the substrate 21. Furthermore, "planar view" refers to the positional relationship when viewed from a direction perpendicular to the substrate 21.

[0023] In this embodiment, the multiple optical sensors PD1, PD2 and the multiple optical sensors PD3, PD4 are arranged to sandwich the light source 60 in the circumferential direction 200C. That is, the detection device 1 is arranged in the following order in the circumferential direction 200C: the multiple optical sensors PD1, PD2, the light source 60, and the multiple optical sensors PD3, PD4. By arranging the multiple optical sensors PD to sandwich the light source 60 in the circumferential direction 200C, the light emitted by the light source 60 can be detected over a wide range of the housing 200.

[0024] The substrate 21 has a cutout portion 22 between both ends in the circumferential direction 200C of the housing 200, i.e., in the longitudinal direction of the substrate 21. The substrate 21 has a plurality of optical sensors PD3 and PD4 mounted on one end 21A of the substrate 21 across the cutout portion 22, and a plurality of optical sensors PD1 and PD2 mounted on the other end 21B. The terminal portion 40 is provided at one end 21A of the substrate 21 in the longitudinal direction. The terminal portion 40 supplies power from the battery 80 to the plurality of optical sensors PD.

[0025] 2 and 3 , the flexible printed circuit board 70 is housed inside the housing 200 so that the surface on which the plurality of optical sensors PD and the light source 60 are mounted is located on the inner periphery of the housing 200. If the flexible printed circuit board 70 is light-transmitting, the plurality of optical sensors PD and the light source 60 may be mounted on the back surface opposite to the front surface. In this case, the light source 60 may be disposed so that it emits light toward the flexible printed circuit board 70 and the light that has passed through the flexible printed circuit board 70 is emitted toward the outside of the housing 200.

[0026] 2, the light source 60 is provided inside the housing 200 and is configured to be able to irradiate light toward the finger Fg wearing the housing 200. The light source 60 is provided, for example, in a region overlapping the cutout portion 22 of the substrate 21. For example, an inorganic LED (Light Emitting Diode) or an organic EL (OLED) is used as the light source 60. The light source 60 irradiates light of a predetermined wavelength.

[0027] In this embodiment, the light source 60 includes a light source 60IR, a light source 60R, and a light source 60G. The light source 60IR emits near-infrared light. The light source 60R emits red light. The light source 60G emits green light. The green light has a wavelength of, for example, 490 nm or more and 550 nm or less. The red light has a wavelength of, for example, 640 nm or more and 770 nm or less. The infrared light has a wavelength of, for example, approximately 2500 nm or more and approximately 25 μm or less. The near-infrared light has a wavelength of, for example, approximately 770 nm or more and approximately 2500 nm or less.

[0028] The light sources 60IR, 60R, and 60G are arranged along the circumferential direction 200C of the housing 200. However, the arrangement of the light sources 60IR, 60R, and 60G is merely an example, and different arrangements may be used. In the following description, when there is no need to distinguish between the light sources 60IR, 60R, and 60G, they will be simply referred to as light sources 60. The light source 60 includes three light sources: the light source 60IR, the light source 60R, and the light source 60G, but may include four or more light sources.

[0029] Light emitted from the light source 60 is reflected by the surface of the object to be detected, such as a finger Fg, and enters the multiple optical sensors PD. This allows the detection device 1 to detect a fingerprint by detecting the uneven shape of the surface of the finger or the like. Alternatively, the light emitted from the light source 60 may be reflected inside the finger Fg or the like or may pass through the finger or the like and enter the multiple optical sensors PD. This allows the detection device 1 to detect information about a living body inside the finger or the like. The information about a living body includes, for example, the pulse wave, pulse rate, and blood vessel image of the finger or palm. In other words, the detection device 1 may be configured as a fingerprint detection device that detects fingerprints, or a vein detection device that detects blood vessel patterns such as veins.

[0030] The detection device 1 of this embodiment detects information about a living body based on light emitted from a light source 60, such as a pulse wave, pulse rate, and blood vessel image, as well as blood oxygen saturation (SpO ２ ) can be detected. In this way, the detection device 1 has light source 60IR, light source 60R, and light source 60G as light sources 60, and performs detection based on light of different wavelengths emitted from each of them, thereby being able to detect information about various living organisms. Note that the above-mentioned emission colors of light source 60IR, light source 60R, and light source 60G are merely examples, and the present disclosure is not limited to the emission colors of light source 60IR, light source 60R, and light source 60G.

[0031] Fig. 5 is a schematic top view showing an example of the configuration of the substrate shown in Fig. 4. Fig. 6 is a cross-sectional view taken along line VI-VI' in Fig. 5. The detection device 1 has a plurality of optical sensors PD as optical sensor elements. Each optical sensor PD outputs an electrical signal corresponding to the light irradiated thereon. More specifically, the optical sensors PD are organic photodiodes (OPDs).

[0032] The optical sensors PD1 and PD2 are provided on the housing 200 so as to be adjacent to one end of the light source 60 in the circumferential direction 200C of the housing 200. The optical sensors PD3 and PD4 are provided on the housing 200 so as to be adjacent to the other end of the light source 60 in the circumferential direction 200C of the housing 200.

[0033] As shown in Figure 5, the optical sensors PD1 and PD2 are configured such that two lower electrodes 11 aligned in the first direction Dx are stacked together with one upper electrode 15A covering the two lower electrodes 11. The optical sensors PD3 and PD4 are configured such that two lower electrodes 11 aligned in the first direction Dx are stacked together with one upper electrode 15B covering the two lower electrodes 11. The upper electrode 15 includes an upper electrode 15A and an upper electrode 15B. Each of the upper electrode 15A and the upper electrode 15B covers two lower electrodes 11 in a plan view. The upper electrode 15A and the upper electrode 15B have rectangular surfaces and are independent electrodes that are not electrically connected.

[0034] The substrate 21 has a first power supply electrode 25A and a second power supply electrode 25B extending along the second direction Dy. The first power supply electrode 25A is provided between one end 21A of the substrate 21 in the first direction Dx and the optical sensors PD1 and PD2. The second power supply electrode 25B is provided between the other end 21B of the substrate 21 in the first direction Dx and the optical sensors PD3 and PD4. The first power supply electrode 25A is electrically connected to a terminal portion 40 of the substrate 21 via a first wiring 26A, and a power signal is supplied from a power supply circuit 54 (see FIG. 7 ) via the terminal portion 40. The second power supply electrode 25B is electrically connected to a terminal portion 40 of the substrate 21 via a second wiring 26B, and a power signal is supplied from the power supply circuit 54 via the terminal portion 40.

[0035] The upper electrodes 15A of the optical sensors PD1 and PD2 are connected to the first power supply electrode 25A via the conductive material 24 and are electrically connected to the terminal unit 40 via the first wiring 26A connected to the first power supply electrode 25A. The upper electrodes 15B of the optical sensors PD3 and PD4 are connected to the second power supply electrode 25B via the conductive material 24 and are electrically connected to the terminal unit 40 via the second wiring 26B connected to the second power supply electrode 25B. As a result, the upper electrodes 15A and 15B are supplied with power from the independent power systems of the first power supply electrode 25A and the second power supply electrode 25B. The conductive material 24 is made of a conductive material and covers the entire surface of the first power supply electrode 25A or the second power supply electrode 25B, electrically connecting the first power supply electrode 25A to the upper electrode 15A and the second power supply electrode 25B to the upper electrode 15B. The upper electrode 15A may be directly connected to the first and second power supply electrodes 25A and 25B without the conductive material 24 therebetween.

[0036] Each of the lower electrodes 11 of the plurality of optical sensors PD is connected to the terminal portion 40 via the third wiring 26C. The plurality of third wirings 26C of the substrate 21 are connected to the detection circuit 51 of the control circuit 50 via the terminal portion 40 and the signal lines of the flexible printed circuit board 70. In other words, the detection circuit 51 is electrically connected to the lower electrodes 11 of the plurality of optical sensors PD via the signal lines. Note that the detection circuit 51 may be formed as a circuit separate from the control circuit 50.

[0037] The first power supply electrode 25A and the second power supply electrode 25B receive a power supply signal from the power supply circuit 54 via the terminal portion 40, and supply the power supply signal to the upper electrode 15A and the upper electrode 15B. In the example shown in Fig. 5, the first power supply electrode 25A and the second power supply electrode 25B are formed in a substantially rectangular shape extending in the second direction Dy in a plan view, and have the same area (size).

[0038] 5, the substrate 21 has an area for the optical sensors PD1 and PD2 and an area for the optical sensors PD3 and PD4, and is formed as a single, integrally formed common substrate. The substrate 21 has a cutout portion 22 formed in the first direction Dx between the area for the optical sensors PD1 and PD2 and the area for the optical sensors PD3 and PD4. The substrate 21 has a connecting portion 23 that contacts the cutout portion 22 and is located between the optical sensors PD1 and PD2 and the optical sensors PD3 and PD4.

[0039] The cutout portion 22 is formed over a distance in the first direction Dx that is longer than the length of the light source 60. The cutout portion 22 is formed over a distance in the second direction Dy that is longer than the length of the light source 60 but shorter than the length (width) of the substrate 21. The substrate 21 is integrally formed by connecting the areas of the optical sensors PD1 and PD2 and the optical sensors PD3 and PD4 via a connecting portion 23 of the cutout portion 22. The cutout portion 22 is formed in a shape that allows the light source 60 to be disposed therein. In this embodiment, the cutout portion 22 is formed in a substantially rectangular shape in a plan view, but may be shaped, for example, semicircular, triangular, polygonal, or the like. The connecting portion 23 is provided with a second wiring 26B and a third wiring 26C.

[0040] As shown in FIG. 6 , the third wiring 26C is provided on the upper surface of the substrate 21. The third wiring 26C is formed, for example, of a metal wiring, and is formed of a material having better conductivity than the lower electrode 11 of the photosensor PD. The third wiring 26C is provided in a layer between the substrate 21 and the photosensor PD in the third direction Dz. The third wiring 26C is electrically connected to the terminal portion 40 on the substrate 21 (see FIG. 5 ). Note that the third wiring 26C may be formed, for example, in the same layer as the lower electrode 11, or may be formed of metal. The insulating layer 27 is provided on the substrate 21, covering the third wiring 26C. The insulating layer 27 may be an inorganic insulating film or an organic insulating film.

[0041] The optical sensor PD is provided as a sensor element on the insulating layer 27. The optical sensor PD has a lower electrode 11, a lower buffer layer 12, an active layer 13, an upper buffer layer 14, and an upper electrode 15 (upper electrode 15A). In the optical sensor PD, the lower electrode 11, the lower buffer layer 12, the active layer 13, the upper buffer layer 14, and the upper electrode 15 are stacked in this order in a third direction Dz perpendicular to the substrate 21.

[0042] The lower electrode 11 is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide).

[0043] The characteristics (for example, voltage-current characteristics and resistance value) of the active layer 13 change depending on the light irradiated thereto. An organic material is used as the material of the active layer 13. Specifically, the active layer 13 has a bulk heterostructure in which a p-type organic semiconductor and an n-type organic semiconductor, an n-type fullerene derivative (PCBM), are mixed. For example, a low-molecular organic material, C ６０ (fullerene), PCBM (phenyl C ６１ Phenyl C61-butyric acid methyl ester), CuPc (Copper Phthalocyanine), F １６ CuPc (fluorinated copper phthalocyanine), rubrene (5,6,11,12-tetraphenyltetracene), PDI (a derivative of perylene), or the like can be used.

[0044] The active layer 13 can be formed by a vapor deposition (dry process) using these low molecular weight organic materials. In this case, the active layer 13 is formed by, for example, CuPc and F １６ CuPc laminated film or rubrene and C ６０The active layer 13 may be a laminated film of the above-mentioned low molecular weight organic material and high molecular weight organic material. The active layer 13 may also be formed by a coating process (wet process). In this case, the active layer 13 is made of a material that combines the above-mentioned low molecular weight organic material and high molecular weight organic material. Examples of high molecular weight organic materials that can be used include P3HT (poly(3-hexylthiophene)) and F8BT (F8-alt-benzothiadiazole). The active layer 13 may be a film in which P3HT and PCBM are mixed, or a film in which F8BT and PDI are mixed.

[0045] The lower buffer layer 12 and the upper buffer layer 14 are provided to facilitate the holes and electrons generated in the active layer 13 reaching the lower electrode 11 or the upper electrode 15. One of the lower buffer layer 12 and the upper buffer layer 14 is a hole transport layer. The other of the lower buffer layer 12 and the upper buffer layer 14 is an electron transport layer. The material of the hole transport layer is a metal oxide layer. As the metal oxide layer, tungsten oxide (WO ３ ), molybdenum oxide, etc. The material of the electron transport layer is ethoxylated polyethyleneimine (PEIE).

[0046] The materials and manufacturing methods of the lower buffer layer 12, the active layer 13, and the upper buffer layer 14 are merely examples, and other materials and manufacturing methods may be used. For example, the lower buffer layer 12 and the upper buffer layer 14 are not limited to single-layer films, and may be formed as multilayer films including an electron blocking layer and a hole blocking layer.

[0047] The upper electrode 15 is provided on the upper buffer layer 14. The upper electrode 15 is formed continuously over the entire photosensor PD. In other words, the upper electrode 15 is provided continuously over the multiple photosensors PD. The upper electrode 15 faces the multiple lower electrodes 11, with the lower buffer layer 12, the active layer 13, and the upper buffer layer 14 sandwiched between them. The upper electrode 15 is formed of a light-transmitting conductive material such as ITO or IZO. A portion of the end of the upper surface 150 of the upper electrode 15 is electrically connected to the conductive material 24. The conductive material 24 is electrically connected to the first power supply electrode 25A and supplies a power signal from the first power supply electrode 25A to the upper electrode 15.

[0048] The sealing film 90 is provided on the upper electrode 15. The sealing film 90 is made of an inorganic film such as a silicon nitride film or an aluminum oxide film, or a resin film such as acrylic. The sealing film 90 is not limited to a single layer, but may be a laminated film of two or more layers combining the inorganic film and the resin film. The sealing film 90 effectively seals the photosensor PD and can prevent moisture from entering from the upper surface side. In this embodiment, the photosensor PD is configured to protect the terminal portion 40, the substrate 21, etc. by covering the sealing film 90 to a portion of the terminal portion 40 with a resin 91.

[0049] 7 is a block diagram showing an example of the configuration of a detection device according to an embodiment. As shown in Fig. 7, a control circuit 50 outputs control signals to the optical sensor PD, battery 80, battery-driven circuit 81, coil 82, light source drive circuit 101, temperature sensor 83, motion sensor 84, and antenna-integrated communication device 103, respectively, to control the operation of each component. The control circuit 50 includes, for example, a detection circuit 51, a communication circuit 52, a memory circuit 53, a power supply circuit 54, an arithmetic circuit 55, a timing control circuit 56, a temperature measurement circuit 57, and a motion measurement circuit 58.

[0050] The detection circuit 51 is a current detection circuit that measures the photocurrent Id output from the optical sensor PD. The detection circuit 51 includes, for example, an integration circuit 46 and an A / D conversion circuit 47 (see FIG. 8). The detection circuit 51 measures the photocurrent Id output from the optical sensor PD, performs signal processing such as A / D conversion, and outputs a sensor value (pulse wave) corresponding to the photocurrent Id to the host 220 (see FIG. 9).

[0051] The light source drive circuit 101 outputs a light source drive signal ILED to the light source 60 based on a control signal from the control circuit 50, and controls the turning on and off of the light source 60.

[0052] The temperature sensor 83 and the temperature measurement circuit 57 measure the temperature (body temperature) of the object to be detected. The motion sensor 84 and the motion measurement circuit 58 detect the posture and movement of the object to be detected. The motion sensor 84 may have any configuration depending on the usage mode of the detection device 1 and the required detection accuracy, but may be configured, for example, to include a three-axis acceleration sensor, a three-axis gyro sensor, and a three-axis geomagnetic sensor.

[0053] The communication circuit 52 and the communication device with built-in antenna 103 wirelessly transmit and receive various information to and from an external host 220 (see FIG. 9 ). The communication circuit 52 and the communication device with built-in antenna 103 support wireless communication standards. The communication standards include, for example, cellular phone communication standards such as 3G, 4G, and 5G, and short-range wireless communication standards. The communication circuit 52 and the communication device with built-in antenna 103 supply the received information to each component of the control circuit 50. The communication circuit 52 and the communication device with built-in antenna 103 transmit various information acquired by the light sensor PD, the temperature sensor 83, and the motion sensor 84 to the external host 220 (see FIG. 9 ).

[0054] The battery drive circuit 81 is a circuit that controls charging of the battery 80. The coil 82 is a coil for charging the battery 80. The battery 80 of the detection device 1 is configured to be contactlessly chargeable by the coil 82. The power supply circuit 54 of the control circuit 50 supplies reference potentials Vorg and Vref to the optical sensor PD based on power Pw from the battery 80, and also supplies a light source drive signal ILED to the light source 60. The power supply circuit 54 supplies power to the communication circuit 52, the temperature measurement circuit 57, the motion measurement circuit 58, etc. as necessary.

[0055] The memory circuit 53 of the control circuit 50 temporarily stores information such as the pulse wave measured by the detection circuit 51. The calculation circuit 55 calculates the pulse wave interval (hereinafter referred to as RRI (R-R Interval)), the average value of the RRI, the standard deviation, etc., based on the information such as the pulse wave measured by the detection circuit 51. The pulse wave interval (RRI), the average value of the RRI, and the standard deviation will be described later with reference to FIG. 10 and subsequent figures.

[0056] The timing control circuit 56 of the control circuit 50 controls the various parts of the control circuit 50 to operate synchronously or asynchronously.

[0057] 8 is a circuit diagram showing an example configuration of a detection device according to an embodiment. As shown in FIG. 8, a plurality of optical sensors PD1, PD2, PD3, and PD4 are connected to an integrating circuit 46 included in a detection circuit 51 via connection switches SSW1, SSW2, SSW3, and SSW4. The detection device 1 also includes a constant current source 48. The constant current source 48 is connected to a connection node N1 between the plurality of optical sensors PD1, PD2, PD3, and PD4 and the integrating circuit 46 via an offset switch ofs.

[0058] In the following description, when it is not necessary to distinguish between the connection switches SSW1, SSW2, SSW3, and SSW4, they will be simply referred to as connection switches SSW.

[0059] The anode of the optical sensor PD is supplied with a reference potential Vorg from the power supply circuit 54. The cathode of the optical sensor PD is connected to the detection circuit 51 via a connection switch SSW.

[0060] The sensor capacitance Cd is connected in parallel to the optical sensor PD and is formed between the upper electrode 15 and the lower electrode 11 of the optical sensor PD.

[0061] The detection circuit 51 includes an integration circuit 46 and an A / D conversion circuit 47. The integration circuit 46 converts fluctuations in the photocurrent Id output from the optical sensor PD into fluctuations in voltage. The A / D conversion circuit 47 converts the analog signal output from the integration circuit 46 into a digital signal.

[0062] The integrator circuit 46 includes an operational amplifier 45, a feedback capacitor Cfb, and a reset switch rsw. The inverting input (-) of the operational amplifier 45 is connected to the optical sensor PD via a connection switch SSW. The optical sensors PD1, PD2, PD3, and PD4 are connected in parallel to the inverting input (-) of the integrator circuit 46 via a plurality of connection switches SSW1, SSW2, SSW3, and SSW4.

[0063] A reference potential Vref is supplied to the non-inverting input (+) of the operational amplifier 45 from the power supply circuit 54. The output of the operational amplifier 45 is connected to the A / D conversion circuit 47. The output voltage Vout of the integrating circuit 46 is the voltage value at a connection node N2 between the operational amplifier 45 and the A / D conversion circuit 47.

[0064] In this embodiment, when light is irradiated onto the optical sensor PD during the exposure period, a current corresponding to the amount of light flows through the optical sensor PD, and thereby, charge is accumulated in the sensor capacitance Cd.

[0065] The reset switch rsw is turned on for a predetermined period including the exposure period, and the integration circuit 46 is in a reset state. The reset switch rsw is turned off at a timing before the readout period, and the integration circuit 46 is released from the reset state.

[0066] When the connection switch SSW is turned on, a readout period begins, and a current flows through the integrating circuit 46 of the detection circuit 51 in accordance with the charge accumulated in the sensor capacitance Cd. As a result, the photocurrent Id is calculated. In addition, the offset current Idac adjusts the current flowing through the integrating circuit 46.

[0067] The A / D conversion circuit 47 processes the output voltage Vout output from the integration circuit 46 and outputs a sensor value corresponding to the photocurrent Id to the host 220 .

[0068] 9 is a block diagram showing an example configuration of a detection system including a detection device according to an embodiment. As shown in FIG. 9, a detection system 110 including the detection device 1 includes a host 220 and a server device 300 on a cloud that is connectable to the host 220. The host 220 is, for example, a mobile terminal such as a smartphone, a mobile phone, or a tablet terminal. A communication circuit 221 of the host 220 can wirelessly transmit and receive data to and from the detection device 1 and the server device 300. Note that the server device 300 is not limited to being configured on a cloud.

[0069] The server device 300 includes, for example, a data storage circuit 301 and a data calculation circuit 302. Information about the subject measured by the detection device 1, such as data related to the RRI, the average value of the RRI, and the standard deviation, is transmitted to the server device 300 via the host 220. The various data transmitted to the server device 300 is stored in the data storage circuit 301. The data storage circuit 301 stores various biological information about the subject as vital data, not limited to the RRI. Furthermore, the data calculation circuit 302 performs calculation processing of the RRI, and the calculation results are stored in the data storage circuit 301.

[0070] Next, a method for measuring the pulse wave interval (RRI) and a method for acquiring various data using the detection device 1 and the detection system 110 will be described. FIG. 10 is a flowchart for explaining a method for measuring the RRI, the average value and standard deviation of the RRI using the detection device according to the embodiment. FIG. 11 is a flowchart for explaining a method for analyzing the frequency of the RRI using the detection device and the detection system according to the embodiment. FIG. 12 is an explanatory diagram for explaining the pulse wave and RRI measured by the detection device. FIG. 13 is a graph schematically showing the relationship between the RRI and time. FIG. 14 is an explanatory diagram for explaining another example of a method for measuring the RRI and a method for calculating the average value and standard deviation of the RRI.

[0071] 10 , the detection device 1 drives the optical sensor PD and the light source 60 to measure pulse wave data of the subject (pulse wave measurement flow). First, the light source drive circuit 101 turns on the light source 60 based on a control signal from the control circuit 50 (step ST1). The light source drive circuit 101 turns on, for example, the light source 60G, which emits green light.

[0072] A photocurrent Id flows through the optical sensor PD in response to light irradiated from the light source 60. The detection circuit 51 measures the photocurrent Id output from the optical sensor PD (step ST2). The detection circuit 51 performs the above-described signal processing on the measured photocurrent Id (step ST3).

[0073] In the graph shown in Fig. 12, the vertical axis represents the output voltage Vout of the detection circuit 51 (integration circuit 46), and the horizontal axis represents time (s). As shown in Fig. 12, the detection circuit 51 measures pulse wave data of the subject based on the photocurrent Id from the optical sensor PD. The pulse wave data has a waveform in which the maximum and minimum values ​​of the output voltage Vout are periodically repeated. The memory circuit 53 (see Fig. 7) stores the pulse wave data acquired by the detection circuit 51 (step ST4).

[0074] Next, the connection switch SSW (see FIG. 8) is turned off to end the readout period, and the detection circuit 51 stops signal processing of the photocurrent Id (step ST5) and stops measuring the photocurrent Id from the photosensor PD (step ST6). The light source drive circuit 101 turns off the light source 60 based on the control signal from the control circuit 50 (step ST7).

[0075] As described above, the detection device 1 stops driving the optical sensor PD and the light source 60, and ends measurement of the pulse wave data of the subject (step ST8).

[0076] Next, the arithmetic circuit 55 (see FIG. 7) calculates the RRI and various data using the pulse wave data acquired in steps ST1 to ST8 (RRI calculation flow).

[0077] First, the arithmetic circuit 55 calculates the times at which the output voltage Vout reaches its minimum value in the acquired pulse wave data (see FIG. 12) (step ST9). In the example shown in FIG. 12, the arithmetic circuit 55 calculates the times t1, t2, t3, t4, t5, ... at which the output voltage Vout reaches its minimum value.

[0078] The arithmetic circuit 55 calculates the period Δt(RRI) between adjacent minimum values ​​of the output voltage Vout (step ST10). In the present disclosure, the pulse wave interval (RRI) is the period Δt between adjacent minimum values ​​of the output voltage Vout in the pulse wave data. In the example shown in FIG. 12, the periods Δt(RRI) are calculated as Δt(RRI)=t2-t1, t3-t2, t4-t3, and t5-t4, respectively. FIG. 12 illustrates Δt(RRI)=t4-t3 as an example of RRI. In addition, in step ST10, the arithmetic circuit 55 may calculate various other data, such as the amplitude PA of the pulse wave, as necessary.

[0079] As shown in FIG. 13 , the arithmetic circuit 55 may calculate the RRI for each beat during a continuous predetermined period (a period from 0 to 250 seconds). Alternatively, as shown in FIG. 14 , the arithmetic circuit 55 may calculate the RRI based on pulse wave data corresponding to a predetermined measurement period HRT. The measurement period HRT is, for example, 30 seconds or longer. That is, the arithmetic circuit 55 includes a measurement period HRT during which the RRI is calculated and a stop period (for example, 60 seconds or longer) during which the RRI calculation is stopped, and alternates between calculating the RRI during the measurement period HRT and a predetermined stop interval. In this case, the detection device 1 can reduce power consumption while acquiring data necessary for RRI analysis.

[0080] The memory circuitry 53 stores the RRIs acquired in steps ST9 and ST10 (step ST11). The memory circuitry 53 stores the RRIs in association with the respective measurement times, as shown in Fig. 13. Alternatively, the memory circuitry 53 stores the RRIs in association with the respective measurement periods HRT, as shown in Fig. 14.

[0081] The arithmetic circuit 55 calculates the average value and standard deviation of the RRI based on the stored RRI (step ST12). FIG. 14 shows an example of calculating the average value (μ) and standard deviation (σ) of the RRI for each measurement period HRT. The detection device 1 can calculate, for example, heart rate variability (HRV) based on the average value (μ) and standard deviation (σ) of the RRI. Heart rate variability (HRV) is expressed as μ±σ and is used to analyze autonomic nervous activity.

[0082] The memory circuitry 53 stores the mean value (μ) and standard deviation (σ) of the RRI obtained in step ST12 (step ST13).

[0083] The control circuit 50 transmits the RRI, the average value of the RRI, and the standard deviation acquired in steps ST9 to ST13 to the host 220 (see FIG. 9) via the communication circuit 52 (see FIG. 7) (step ST14). In the following description, various data related to the RRI, including the RRI, the average value of the RRI, and the standard deviation, may be referred to as "pulse interval data."

[0084] The host 220 transmits the pulse interval data (RRI, average value of RRI, and standard deviation) acquired from the detection device 1 to the server device 300 on the cloud (step ST15).

[0085] 11 , the cloud-based server device 300 analyzes the pulse interval data acquired in step ST15 (frequency analysis flow). The data calculation circuit 302 included in the cloud-based server device 300 uses the RRI acquired in step ST15 to perform a fast Fourier transform (FFT) calculation (step ST16). As a result, the data calculation circuit 302 calculates the frequency dispersion of the RRI.

[0086] The data calculation circuit 302 of the server device 300 integrates a predetermined frequency range (0.04 Hz to 0.15 Hz) based on the frequency dispersion of the RRI (step ST17) and stores the result as vital data in the data storage circuit 301 (step ST19). The data calculation circuit 302 of the server device 300 also integrates a predetermined frequency range (0.15 Hz to 0.4 Hz) based on the frequency dispersion of the RRI (step ST18) and stores the result as vital data in the data storage circuit 301. Note that by setting the RRI measurement period HRT shown in FIG. 14 to, for example, 30 seconds or more, the integration in the frequency range shown in step ST17 can be performed satisfactorily.

[0087] The server device 300 also stores the pulse interval data (average RRI value and standard deviation) acquired in step ST15 as vital data. The server device 300 also acquires other vital data, not limited to the pulse interval data, from the detection device 1 or the host 220, and executes data processing of the other vital data using the data calculation circuit 302 (step ST20). The other vital data is also stored in the data storage circuit 301.

[0088] Other vital data include, for example, blood oxygen saturation (SpO ２ ) data acquired by the motion sensor 84, and data acquired by the temperature sensor 83. These data are transmitted from the detection device 1 to the server device 300 on the cloud via the host 220.

[0089] Other vital data may include sleep time, METs (physical activity intensity), number of steps, distance traveled, calories, etc. These vital data are detected by at least one of the light sensor PD, the temperature sensor 83, and the motion sensor 84.

[0090] As described above, the detection device 1 and the detection system 110 measure the pulse wave data of the subject using the optical sensor PD and calculate the pulse wave interval (RRI) based on the pulse wave data corresponding to a predetermined period of time. The pulse wave interval data (RRI, average RRI value, and standard deviation) is transmitted to the server device 300 on the cloud via the host 220. The detection device 1 and the detection system 110 can monitor the mental and physical state of the subject by acquiring the pulse wave interval data (RRI, average RRI value, and standard deviation). Furthermore, the detection device 1 and the detection system 110 can use the pulse wave interval data (RRI, average RRI value, and standard deviation) to analyze autonomic nervous activity and predict various mental and physical disorders, for example.

[0091] The methods for measuring the RRI and for acquiring various data shown in Figures 10 to 14 are merely examples and can be modified as appropriate. The RRI is defined as the period Δt between adjacent minimum values ​​in the pulse wave data, but this is not limiting. For example, the RRI may be defined as the period Δt between adjacent maximum values ​​in the pulse wave data. Steps ST14 and ST15 shown in Figure 10 illustrate an example in which the RRI, the average value of the RRI, and the standard deviation are transmitted as pulse wave interval data, but this is not limiting. The detection device 1 may transmit at least the RRI and at least one of the average value and standard deviation of the RRI.

[0092] Although the detection device 1 has been described as containing the substrate 21 and the like inside the ring-shaped housing 200, the present invention is not limited to this. The detection device 1 may be, for example, contained in a rectangular housing, or may be attached to the object to be measured without being contained in a housing.

[0093] Although preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible within the scope of the present disclosure. Appropriate modifications made within the scope of the present disclosure naturally fall within the technical scope of the present disclosure. At least one of various omissions, substitutions, and modifications of components can be made within the scope of the gist of each of the above-described embodiments and modifications.

[0094] REFERENCE SIGNS LIST 1 Detection device 21 Substrate 45 Operational amplifier 46 Integration circuit 47 A / D conversion circuit 48 Constant current source 50 Control circuit 51 Detection circuit 52 Communication circuit 53 Memory circuit 54 Power supply circuit 55 Arithmetic circuit 60, 60IR, 60R, 60G Light source 83 Temperature sensor 84 Motion sensor 110 Detection system 200 Housing 220 Host 300 Server device PD, PD1, PD2, PD3, PD4 Optical sensor

Claims

1. A detection device comprising: an optical sensor; a detection circuit that measures a photocurrent output from the optical sensor; and a memory circuit that stores pulse wave data of a detected body obtained by the detection circuit, wherein the detection circuit calculates a pulse wave interval based on pulse wave data corresponding to a predetermined period of time from the pulse wave data, stores the pulse wave interval in the memory circuit, and outputs the stored pulse wave interval.

2. The detection device according to claim 1, wherein the pulse wave interval is the period between adjacent minimum values ​​in the pulse wave data.

3. The detection device according to claim 1, wherein the predetermined period is 30 seconds or more.

4. The detection device according to claim 1, wherein a period during which the pulse wave interval is calculated during the predetermined period and a stop period during which the calculation of the pulse wave interval is stopped are alternated.

5. The detection device according to claim 1, further comprising: a detecting device which calculates at least one of an average value and a standard deviation of the pulse wave interval during the specified period based on the pulse wave interval; and outputs at least one of the average value and the standard deviation of the pulse wave interval.

6. A detection system comprising: a detection device according to any one of claims 1 to 5; and a server device on a cloud to which the pulse wave interval is transmitted from the detection device via a host, wherein the server device on the cloud uses the pulse wave interval to perform a fast Fourier transform (FFT) calculation, integrates a predetermined frequency range, and stores the result as vital data.

7. The detection system of claim 6, wherein the detection device calculates at least one of an average value and a standard deviation of the pulse wave interval during the specified period based on the pulse wave interval, and at least one of the average value and the standard deviation of the pulse wave interval is transmitted from the detection device via the host to a server device on the cloud.

8. The detection system according to claim 6, wherein the predetermined frequency range is from 0.04 Hz to 0.15 Hz.

9. The detection system according to claim 6, wherein the predetermined frequency range is from 0.15 Hz to 0.4 Hz.

10. The detection system of claim 6, wherein the detection apparatus is a ring-shaped device.

11. The detection system of claim 6, wherein the detection device is incorporated into a watch or wristband.

12. The detection system according to claim 6, wherein the optical sensor is an OPD (Organic Photodiode).

13. The device further includes at least one of a motion sensor and a temperature sensor, and the data acquired by the motion sensor, the data acquired by the temperature sensor, and the SpO2 acquired by the optical sensor are stored in the storage medium. ２ The detection system according to claim 6 , wherein at least one of the data is transmitted to a server device on the cloud.

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