JP6197926B2 - Biological information detection apparatus, biological information detection method, and biological information detection program - Google Patents

Description

  The present invention relates to a biological information detection device, a biological information detection method, and a biological information detection program, and in particular, a biological information detection device, a biological information detection method, and a biological information that are equipped with a pulse measurement function that is attached to a human body during exercise and measures a pulse. It relates to an information detection program.

  In recent years, with increasing health consciousness, an increasing number of people maintain and improve their health by performing daily exercises such as running, walking, and cycling. Among such people, various kinds of biological information are measured and recorded in order to grasp their own health state and exercise state. There are various physiological indexes as biological information for grasping the state of the human body. As one of them, for example, the heart rate which is the number of heart beats per minute is well known. As a heart rate measurement method, an electrocardiogram method is generally known. However, in this method, it is necessary to attach a plurality of electrodes to the chest, so that the activities during daily life and exercise are restricted or the electrodes are attached. May be complicated and give a lot of burden to the user (user) of the measuring device. Therefore, today, as a physiological index that can be measured more easily, a technique of measuring a pulse instead of a heartbeat is often used.

  As a pulse measurement method, for example, a photoelectric pulse wave method (or an optical pulse wave detection method) is known. The principle of the photoelectric pulse wave method is to detect an observation signal corresponding to a pulse wave by utilizing the light absorption characteristic of hemoglobin in blood. That is, the pulse wave is a pressure change in the artery caused by the heartbeat transmitted to the peripheral artery as a wave, and light such as infrared rays is transmitted through the skin to irradiate the blood in the peripheral artery, and is scattered by the blood. By measuring a temporal change in the intensity of reflected light due to the emitted light as an observation signal, a pulse wave indicating a wave-like flow change in the blood flow of the peripheral artery can be detected. According to such a photoelectric pulse wave method, a pulse wave can be obtained from a finger, an earlobe, a wrist or the like, and a pulse can be easily obtained based on the pulse wave.

  However, the blood flow changes with the movement (body movement) during daily life and exercise, so the photoelectric pulse wave method is greatly affected by this blood flow change (body movement noise). There is a problem that body motion noise is mixed. On the other hand, as one of methods for obtaining the pulse wave signal by removing the signal component of the body movement noise from the observation signal in which the pulse wave signal and the body movement noise are conventionally mixed, for example, as described in Patent Document 1 In addition, a method is known in which body motion noise is regarded as an acceleration signal acquired by an accelerometer, and a difference signal between an observation signal and an acceleration signal is used as a pulse wave signal.

JP 2003-102694 A

  In the method of acquiring a pulse wave signal as described above, since the acceleration signal is regarded as equal to body motion noise and signal processing is performed, the pulse wave signal can be acquired by relatively simple signal processing. However, according to the verification by the present inventor, the acceleration signal and the body motion noise acquired during the movement of the human body are not necessarily the same. For example, the acceleration signal and the body motion noise have different amplitudes or accelerations. It has been found that there is a time difference (time lag) from the time of occurrence to the time when the effect appears in the observation signal. However, the above-mentioned method did not consider such a point at all. For this reason, the above-described method cannot properly remove a noise component due to body movement included in the observation signal, and cannot accurately measure the pulse rate during the movement of the human body.

  Therefore, in view of the above-described problems, the present invention provides a biological information detection apparatus and biological information detection capable of appropriately estimating a body motion noise component accompanying a user's motion in an observation signal and detecting an accurate pulse wave. It is an object to provide a method and a biological information detection program.

The biological information detection apparatus according to the present invention is
A detection unit that outputs an observation signal detected based on a pulse wave of at least one observation part of the user;
An acceleration measuring unit that outputs at least one acceleration signal corresponding to at least one axial direction, which is measured in accordance with the user's movement;
Based on a comparison between the observed acceleration signal and a synthesized acceleration signal obtained by synthesizing the acceleration signal based on at least one parameter, a specific parameter of the parameter corresponding to an acceleration component corresponding to the user's action in the observation signal A parameter estimator for estimating the value;
A pulse rate calculation unit that calculates the pulse rate of the user as biological information from a difference signal obtained by removing a specific synthesized acceleration signal corresponding to the specific value of the parameter from the observation signal;
It is characterized by providing.

The biological information detection method according to the present invention includes:
Acquiring an observation signal based on a pulse wave of at least one observation part of the user, and acquiring at least one acceleration signal corresponding to at least one axial direction associated with the user's movement,
Based on a comparison between the observed acceleration signal and a synthesized acceleration signal obtained by synthesizing the acceleration signal based on at least one parameter, a specific parameter of the parameter corresponding to an acceleration component corresponding to the user's action in the observation signal Estimate the value,
The pulse rate of the user is calculated as biological information from a difference signal obtained by removing a specific synthetic acceleration signal corresponding to the specific value of the parameter from the observation signal.

The biological information detection program according to the present invention is
On the computer,
At least one acceleration signal corresponding to at least one axial direction associated with the user's movement is acquired from the detection unit that outputs an observation signal based on a pulse wave of at least one observation part of the user. The acceleration signal is acquired from the acceleration measuring unit that outputs
Based on a comparison between the observed acceleration signal and a combined acceleration signal obtained by synthesizing the acceleration signal based on at least one parameter, the acceleration signal corresponding to an acceleration component based on the user's action, Estimate a specific value of a parameter,
The pulse rate of the user is calculated as biological information from a difference signal obtained by removing a specific synthetic acceleration signal corresponding to the specific value of the parameter from the observation signal.

  According to the present invention, it is possible to appropriately estimate a body motion noise component accompanying a user's motion and detect an accurate pulse wave (particularly an instantaneous pulse wave).

It is the schematic which shows the example of mounting | wearing of the biological information detection apparatus which concerns on this invention, and the external appearance structural example. It is the schematic which shows the structural example of the measurement surface of the biological information detection apparatus which concerns on this invention. It is a block diagram which shows the example of 1 structure of the biometric information detection apparatus which concerns on 1st Embodiment. It is a flowchart which shows the stationary pulse wave measurement operation | movement performed in the biometric information detection method of the biometric information detection apparatus which concerns on 1st Embodiment. It is a conceptual diagram which shows an example of the multipoint observation of the pulse wave performed in the stationary pulse wave measurement operation | movement which concerns on 1st Embodiment. It is a wave form diagram which shows an example of the pulse wave signal acquired by the stationary pulse wave measurement operation | movement which concerns on 1st Embodiment. It is a flowchart which shows the operation time pulse wave measurement operation | movement performed in the biometric information detection method of the biometric information detection apparatus which concerns on 1st Embodiment. It is a conceptual diagram for demonstrating the extreme value interval calculated in the operation time pulse-wave measurement operation | movement which concerns on 1st Embodiment. It is a wave form chart showing an example of each signal acquired by operation time pulse wave measurement operation concerning a 1st embodiment. It is a flowchart which shows the time lag and rotation angle estimation process performed in the operation time pulse-wave measurement operation | movement which concerns on 1st Embodiment. It is a conceptual diagram for demonstrating the triaxial direction defined in the operation time pulse-wave measurement operation | movement which concerns on 1st Embodiment. It is a figure which shows an example of the normalized cross correlation coefficient computed by the time lag and rotation angle estimation process which concerns on 1st Embodiment. It is a figure which shows an example of transition of the rotation angle acquired by the time lag and rotation angle estimation process which concerns on 1st Embodiment, and a maximum value. It is a flowchart which shows the amplitude estimation process performed in the operation time pulse-wave measurement operation | movement which concerns on 1st Embodiment. It is the schematic which shows the structural example of the measurement surface of the biological information detection apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the operation time pulse wave measurement operation | movement performed in the biometric information detection method which concerns on 2nd Embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, a biological information detection device, a biological information detection method, and a biological information detection program according to the present invention will be described in detail with reference to embodiments.
<First Embodiment>
(Biological information detection device)
FIG. 1 is a schematic diagram showing a mounting example and an external configuration example of a biological information detection apparatus according to the present invention. Here, FIG. 1A is a schematic view showing a state where the biological information detecting device according to the present invention is mounted on a human body, and FIG. 1B is a front view and a side view of the biological information detecting device according to the present invention. It is a schematic block diagram which shows. FIG. 2 is a schematic diagram showing a configuration example of a measurement surface of the biological information detection apparatus according to the present invention.

  The biological information detecting apparatus 100 according to the present invention has a wristwatch type (or wristband type) external shape to be worn on a wrist or the like of a user (user) US as shown in FIG. Yes. For example, as shown in FIG. 1B, the biological information detection apparatus 100 is roughly divided into a device main body 101 having a function of measuring the pulse of the user US and providing predetermined information to the user US, and the user US. And a belt portion 102 for attaching the apparatus main body 101 to the wrist USh and bringing it into close contact with the wrist USh.

  A measurement surface is provided on the side of the device main body 101 that contacts the wrist USh (the right side in FIG. 1B). For example, as shown in FIGS. One to a plurality of light emitting elements E1 to E9 and one to a plurality of light receiving elements R1 to R4 are two-dimensionally arranged in a predetermined pattern in a predetermined area (hereinafter referred to as “measurement area” for convenience). It is arranged.

  Here, in the measurement region MS, for example, as shown in FIG. 2A, a plurality of (four) light receiving elements R1 to R4 are arranged around one light emitting element E1. . That is, the light emitting elements and the light receiving elements are arranged in a one-to-many relationship. In the measurement region MS, for example, as shown in FIG. 2B, a plurality of (four) light emitting elements E1 to E4 are disposed around one light receiving element R1. It may be. That is, the light emitting elements and the light receiving elements are arranged in a plural-to-one relationship. Further, in the measurement region MS, as shown in FIG. 2C, a plurality of light emitting elements E1 to E9 are arranged around each of a plurality (four) of the light receiving elements R1 to R4. It may be. That is, the light emitting elements and the light receiving elements are arranged in a plural-to-multiple relationship. Thus, in the present embodiment, at least one of one to a plurality of light emitting elements and one to a plurality of light receiving elements is arranged.

  The number and arrangement of the light emitting elements and the light receiving elements arranged in the measurement region MS are not limited to the patterns shown in FIGS. 2A to 2C, and an arbitrary number of light emitting elements and light receiving elements. May be alternately arranged in an arbitrary pattern such as a staggered pattern, a grid pattern, or an arc pattern.

FIG. 3 is a block diagram illustrating a configuration example of the biological information detection apparatus according to the present embodiment.
Specifically, for example, as shown in FIG. 3, the biological information detection apparatus 100 is roughly divided into a light emitting unit (detecting unit) 10, a light emitting control unit 15, a light receiving unit (detecting unit) 20, and an acceleration measuring unit. 30, a signal amplification unit 40, a filter unit 50, a memory unit 60, a stationary pulse wave amplitude recording unit (storage unit) 65, and a signal processing unit (observation signal selection unit, parameter estimation unit, pulse rate calculation unit) ) 70, a display unit 80, and an operation unit 90.

  The light emitting unit 10 includes the above-described one or more light emitting elements E1 to E9, and as shown in FIGS. 2A to 2C, the measurement region on the surface side in contact with the wrist USh of the device main body 101. The MS is arranged in a predetermined pattern. For example, light emitting diodes (LEDs) can be applied to the light emitting elements E1 to E9, and visible light is emitted with a predetermined light emission intensity (or light emission amount) according to drive control by a light emission control unit 15 described later. Emits light and irradiates the skin surface (body surface) SF of the wrist USh. Here, in the reflection type pulse wave detection method using visible light, since the permeability of visible light in the body is low, it is difficult to be affected by the reflected light from the blood flow of veins and arteries existing deep in the body, It has the feature that it is not easily affected by the propagation time lag of pulsation due to the blood flow path length generated in the blood vessel. As visible light emitted from the light emitting element, for example, green visible light having a wavelength of about 525 nm can be favorably applied.

  In accordance with control from the signal processing unit 70 to be described later, the light emission control unit 15 divides one or more light emitting elements E1 to E9 constituting the light emitting unit 10 into a predetermined lighting pattern (that is, in a predetermined order and a predetermined order). Luminescence intensity).

  The light receiving unit 20 includes one or more light receiving elements R1 to R4 described above, and is arranged in a predetermined pattern in the measurement region MS of the device main body 101 as shown in FIGS. 2 (a) to 2 (c). Has been. For example, phototransistors or illuminance sensors can be applied to the light receiving elements R1 to R4, and the light receiving elements R1 to E9 emit light individually and observe the pulse wave of the skin surface SF. By receiving the light irradiated to the part Pm and scattered by the blood in the blood vessels in the vicinity of the observation part Pm as reflected light, an output signal (observation signal) corresponding to the amount of received light is output.

  The acceleration measuring unit 30 includes a three-axis acceleration sensor, and outputs a change rate (acceleration) of a moving speed applied to the biological information detecting device 100 during the operation of the user US as an acceleration signal. The acceleration signals output from the acceleration measuring unit 30 are output as three acceleration signals corresponding to each of three axial directions orthogonal to each other, consisting of an x axis, a y axis, and a z axis, as will be described later.

  The signal amplifying unit 40 amplifies the observation signal acquired by the light receiving unit 20 and the acceleration signal measured by the acceleration measuring unit 30 to a predetermined signal level suitable for signal processing in the signal processing unit 70 described later. The filter unit 50 passes a signal component in a predetermined frequency band out of the observation signal and the acceleration signal amplified by the signal amplification unit 40 and supplies the signal component to the signal processing unit 70.

  The memory unit 60 includes, for example, a data storage memory (hereinafter referred to as “data memory”), a program storage memory (hereinafter referred to as “program memory”), a work data storage memory (hereinafter referred to as “work memory”). Have the following)

  The data memory has a nonvolatile memory such as a flash memory, and the observation signal acquired by the light receiving unit 20 and the acceleration signal measured by the acceleration measuring unit 30 are time data when the user US operates or exercises. And stored (recorded) in a predetermined storage area. The program memory includes a ROM (read-only memory), and a predetermined memory in each component (light emitting unit 10, light receiving unit 20, acceleration measuring unit 30, display unit 80, operation unit 90, etc., which will be described later) of the biological information detecting apparatus 100. A control program for realizing the function and an algorithm program for realizing the function of calculating the pulse rate based on the above-described observation signal and acceleration signal are stored. The working memory has a RAM (Random Access Memory), and temporarily stores various data used or generated when the above control program and algorithm program are executed. Note that a part or all of the data memory has a form as a removable storage medium such as a memory card, and is configured to be detachable from the device main body 101 of the biological information detecting apparatus 100. May be.

  The stationary pulse wave amplitude recording unit 65 associates the amplitude of the signal wave (pulse wave) of the observation signal acquired by the light receiving unit 20 described above with the time data when the user US is not operating or at rest. And stored (recorded) in a predetermined storage area.

  The signal processing unit 70 is a CPU (central processing unit) or MPU (microprocessor unit), and stores and reads various data in the memory unit 60 by performing processing according to the control program stored in the memory unit 60. It controls the operation, the display operation of various information on the display unit 80, the detection operation of the input operation in the operation unit 90, and the like. In addition, the signal processing unit 70 performs processing according to the algorithm program stored in the memory unit 60, so that an observation signal acquired by the light receiving unit 20 and acceleration measurement are performed as shown in a biological information detection method described later. Based on the acceleration signal measured by the unit 30, an operation for calculating the pulse rate is executed. The control program and algorithm program executed in the signal processing unit 70 may be incorporated in the signal processing unit 70 in advance.

  The display unit 80 includes a display device such as a liquid crystal display panel or an organic EL display panel capable of color or monochrome display, for example, and displays at least the pulse rate calculated by the signal processing unit 70. The display unit 80 displays the pulse wave (pulse waveform data), the moving speed, the number of steps, the current time, etc. in addition to the pulse rate, in characters, numerical information, image information, etc. It may be. Here, for example, pulse waveform data (pulse wave data) includes various information related to blood flow. That is, the pulse data is applied as an important parameter for determining, for example, health, physical condition (blood vessel clogging, blood vessel age, tension state, etc.), exercise state, etc., and the determination results for these are specified characters. Alternatively, the information may be displayed on the display unit 80 using numerical information, image information, a light emission pattern, or the like. In the present embodiment, only the display unit 80 is shown as the output interface for providing or notifying the user US of various types of information. However, the present invention is not limited to this. Other interfaces such as an acoustic unit such as a buzzer or a speaker that generates a timbre or a voice message, or a vibration unit that vibrates with a specific vibration pattern may be provided.

  The operation unit 90 includes a button switch, a slide switch, a keyboard, a touch panel disposed on or integrally formed with the front surface of the display unit 80, and the like. It is used for input operations such as selection and execution of various operations such as an acceleration measurement operation and a display operation on the display unit 80, and a set value.

(Biological information detection method)
Next, a biological information detection method in the above-described biological information detection apparatus will be described.
The biological information detection method in the biological information detection apparatus having the above-described configuration generally includes a stationary pulse wave measurement operation for acquiring a stationary pulse wave observation signal, and a pulse wave observation signal acquired during operation. And an operation pulse wave measurement operation for calculating the pulse rate based on the acceleration signal.

(Pulse wave measurement operation at rest)
FIG. 4 is a flowchart showing a stationary pulse wave measurement operation executed in the biological information detection method of the biological information detection apparatus according to the present embodiment. FIG. 5 is a conceptual diagram showing an example of pulse wave multipoint observation executed in the stationary pulse wave measurement operation according to the present embodiment. FIG. 6 is a waveform diagram showing an example of a pulse wave signal acquired by the stationary pulse wave measurement operation according to the present embodiment.

  In the stationary pulse wave measurement operation, as shown in FIG. 4, first, a pulse wave observation signal and an acceleration signal in a stationary state or a resting state in which the user US is not performing an operation such as exercise are acquired for a certain period of time ( Step S101). Specifically, the signal processing unit 70 displays text information, image information, or the like indicating that the pulse wave at rest is measured on the display unit 80, and prompts the user US to hold the rest state or the rest state. . Next, the signal processing unit 70 designates a combination of a specific light emitting element of the light emitting unit 10 and a specific light receiving element of the light receiving unit 20 and emits the light emitting element designated by the light emission control unit 15 with a predetermined light emission intensity. Then, the region (observation site Pm) where the pulse wave of the skin surface SF of the user US is observed is irradiated with light. A part of the irradiated light is scattered by blood in the blood vessels in the vicinity of the observation site Pm, and is emitted as reflected light from the skin surface SF. The reflected light is received by the designated light receiving element, and an output signal corresponding to the received light amount is output as an observation signal to the signal processing unit 70 via the signal amplification unit 40 and the filter unit 50.

  Here, the observation signal acquisition operation by the combination of the specific light emitting element and the specific light receiving element will be described in detail with reference to the arrangement pattern of the light emitting elements E1 to E9 and the light receiving elements R1 to R4 shown in FIG. explain. First, for example, as shown in FIG. 5A, the signal processing unit 70 includes a light emitting element E1 and a light receiving element R1, a light emitting element E3 and a light receiving element R2, a light emitting element E7 and a light receiving element R3, and a light emitting element E9 and a light receiving element R4. Specify each combination of. Next, the light emission control unit 15 causes each light emitting element E1, E3, E7, E9 to emit light with a predetermined light emission intensity, irradiates each observation site Pm11, Pm32, Pm73, Pm94 of the skin surface SF, and the reflected light thereof Is received by each light receiving element R1, R2, R3, R4. Thereby, the observation signal of the pulse wave at rest in each observation part Pm11, Pm32, Pm73, Pm94 of the skin surface SF is acquired. Here, the operation of acquiring observation signals at each of the observation sites Pm11, Pm32, Pm73, and Pm94 is executed in time series, for example, in the order of the observation sites Pm11, Pm32, Pm73, and Pm94. Note that the observation signal acquisition operation may be executed in parallel at the respective observation sites Pm11, Pm32, Pm73, and Pm94.

  Next, the signal processing unit 70 specifies a combination of the light emitting element E5 and the light receiving elements R1 to R4, for example, as illustrated in FIG. Next, the light emission control unit 15 causes the light emitting element E5 to emit light with a predetermined light emission intensity, irradiates each observation site Pm51, Pm52, Pm53, and Pm54 of the skin surface SF, and the reflected light is applied to each of the light receiving elements R1 to R4. Receives light. Thereby, the observation signal of the stationary pulse wave in each observation part Pm51-Pm54 of skin surface SF is acquired. Here, the observation signal acquisition operation in each of the observation parts Pm51 to Pm54 is executed in time series for each of the observation parts Pm51 to Pm54, as in the case shown in FIG. It may be executed in parallel at each of the observation sites Pm51 to Pm54.

  Hereinafter, similarly, as shown in FIGS. 5C and 5D, for example, as shown in FIGS. 5C and 5D, a combination of the light emitting element E2 and the light receiving elements R1 and R2, and the light emitting element E8 and the light receiving elements R3 and R4. , A combination of the light emitting element E4 and each of the light receiving elements R1 and R3, and a combination of the light emitting element E6 and each of the light receiving elements R2 and R4, respectively, and each observation region Pm21, Pm22, Pm83, Pm84, And the observation signal of the pulse wave at rest in Pm41, Pm62, Pm43, and Pm64 is acquired.

  Through such a series of operations (multi-point observation), pulse wave observation signals are acquired at each observation site between adjacent light emitting elements and light receiving elements arranged in the measurement region MS. Further, such an operation of acquiring the observation signal of the pulse wave is continuously executed for an arbitrary time in which about several to dozens of waveforms indicating the pulse wave are included, for example, a time of about several seconds to 10 seconds.

  On the other hand, in parallel with the operation of acquiring the pulse wave observation signal, the signal processing unit 70 controls the acceleration measurement unit 30 to measure the acceleration of the user US in the three-axis directions. Here, the measurement operation of the three-axis acceleration is continuously executed during the period of the operation of acquiring the pulse wave observation signal described above. The triaxial acceleration measured by the acceleration measuring unit 30 is output as an acceleration signal to the signal processing unit 70 via the signal amplifying unit 40 and the filter unit 50. The pulse wave observation signal and the acceleration signal acquired in this way are associated with each other based on the time data and stored in a predetermined storage area of the memory unit 60.

  Next, it is determined whether or not the amplitude of each acceleration signal in the three-axis directions acquired in step S101 is equal to or less than a predetermined threshold (step S102). Specifically, the signal processing unit 70 reads out the acceleration signal acquired during the operation of acquiring the pulse wave observation signal from the memory unit 60, and for each acceleration signal in the three axis directions, the maximum value and the minimum value of the signal waveform. It is determined whether or not the maximum value (maximum amplitude) of the amplitude that is the difference between the two is equal to or less than a predetermined threshold value for determining a stationary state in which the user US is not performing an action such as exercise. Here, the threshold value for determining the stationary state of the user US can be set to, for example, 5% of the amplitude during an operation such as running. This threshold value may be set based on, for example, a past acceleration signal during operation of the user US, or set based on a general acceleration signal during operation acquired from an unspecified number of samples. It may be set, or may be arbitrarily set when the user US is in a stationary state or a resting state. As will be described later, since the inventor of the present application has found that the acceleration signal in the z-axis direction has little influence on the pulse wave signal, the amplitude of each acceleration signal is not more than a predetermined threshold value. In determining whether or not the amplitude of the acceleration signal in the z-axis direction may not be determined.

  If it is determined in step S102 that the amplitudes of the acquired acceleration signals in the three-axis directions are equal to or less than the threshold value, the average value of the amplitudes of the observation signals of the pulse wave at each observation site at that time is stationary Is recorded as the amplitude of the observed signal (step S103). Specifically, when the signal processing unit 70 determines that the amplitudes of the acquired acceleration signals in the three-axis directions are all equal to or less than the threshold value, the signal processing unit 70 associates the acceleration signal with the acceleration signal based on the time data. Then, the pulse wave observation signals at the respective observation sites stored in the memory unit 60 are read out, and the average value of the amplitude, which is the difference between the maximum value and the minimum value of these signal waveforms, is calculated. Then, the signal processing unit 70 stores (records) the calculated average value in the stationary pulse wave amplitude recording unit 65 as the amplitude of the stationary observation signal, and ends the stationary pulse wave measurement operation.

  On the other hand, if the amplitude of each acquired acceleration signal in the three-axis direction is larger than the threshold value in step S102, an error display for prompting the user US to stop is performed (step S104). Specifically, when the signal processing unit 70 determines that any of the acquired amplitudes of the respective acceleration signals in the three-axis directions is larger than the threshold value, the user US enters the stationary state or the resting state. It is determined that it is not, and the motion such as exercise is stopped on the display unit 80, and text information, image information, etc. for requesting stillness are displayed, and the user US is encouraged to hold the resting state or the resting state. . Next, a reset operation is performed to delete or discard the pulse wave observation signal and acceleration signal acquired in step S101 and stored in the memory unit 60 (step S105), and the process returns to step S101 to return to the above-described series of processing (steps). S101 to S105) are executed again.

  A stationary observation signal obtained by such a stationary pulse wave measurement operation, that is, a signal waveform consisting of an average value of the amplitudes of the observation signals of the pulse wave at each observation part is substantially caused by the operation of the user US. It can be defined that the body motion noise is not included, or the pulse wave signal is in a state where the body motion noise can be substantially ignored. For example, the waveform is as shown in FIG. FIG. 6 shows an example of the signal waveform when the pulse wave at rest is observed for 10 seconds. In FIG. 6, the vertical axis represents a digital value obtained by A / D converting the observation signal acquired by the light receiving unit 20 (light receiving element).

(Pulse wave measurement during operation)
FIG. 7 is a flowchart showing an operation pulse wave measurement operation executed in the biological information detection method of the biological information detection apparatus according to the present embodiment. FIG. 8 is a conceptual diagram for explaining the extreme value interval calculated in the operation pulse wave measurement operation according to the present embodiment. FIG. 9 is acquired by the operation pulse wave measurement operation according to the embodiment. It is a wave form diagram which shows an example of each signal.

  In the operation pulse wave measurement operation, as shown in FIG. 7, first, a pulse wave observation signal and an acceleration signal in an operation state in which the user US is performing an operation such as exercise are acquired for a certain time (step S201). . Specifically, in the same manner as the above-described stationary pulse wave measurement operation, during the operation in which the user US performs an operation such as exercise, the signal processing unit 70 arranges adjacent light emission arranged in the measurement region MS. An observation signal of a pulse wave at each observation site between the element and the light receiving element is acquired for a certain time. Here, the acquisition operation of the pulse wave observation signal is executed for an arbitrary time period in which about several to dozens of waveforms indicating pulse waves are included, as in step S101 of the stationary pulse wave measurement operation described above. The time may be set to the same time as the stationary pulse wave measurement operation (for example, about several seconds to 10 seconds), or may be set to a different time. . On the other hand, during the period of the operation for acquiring the observation signal of the pulse wave, the signal processing unit 70 continuously acquires the acceleration signal in the three-axis direction due to the operation of the user US. The acquired pulse wave observation signal and acceleration signal are associated with each other based on the time data and stored in a predetermined storage area of the memory unit 60.

  Next, similarly to the stationary pulse wave measurement operation described above, the maximum value (maximum amplitude) of the acceleration signals in the three-axis directions acquired in step S201 is equal to or less than a predetermined threshold for determining the stationary state. It is determined whether or not (step S202). When the signal processing unit 70 determines that the amplitude of the acceleration signal is equal to or less than the threshold value, the observation signal having the largest amplitude among the pulse wave observation signals obtained at the respective observation sites obtained in step S201. Is determined as a pulse wave signal that can measure the pulse wave best, and the observation signal is selected (step S203). Here, it is determined that the observation signal selected in step S203 is hardly affected by body motion noise (acceleration component), and the stationary pulse wave amplitude recording unit 65 performs the above-described stationary pulse wave measurement operation. It can be considered that it has a signal waveform equivalent or approximate to the stored observation signal (see FIG. 6). Next, the signal processing unit 70 searches for extreme values for each waveform from the selected observation signal, and calculates the extreme value interval (step S204). Specifically, when the observation signal selected in step S203 has a signal waveform as shown in FIG. 8, for example, the signal processing unit 70 sets each extreme value interval as included in the observation signal. For example, the time when the amplitude in the waveform is the difference between the times Ta and Tb at which the minimum value Pmin is obtained is calculated. In addition, the calculation operation of the extreme value interval in step S204 may be performed on a waveform at an arbitrary time (that is, a representative waveform) among the waveforms included in the selected observation signal, The average value is obtained by averaging multiple extreme value intervals calculated for multiple waveforms included in a certain period of the observed signal, or the median value is extracted from the distribution of multiple extreme value intervals. May be.

  Next, the pulse rate per unit time (for example, 1 minute) is calculated based on the extreme value interval calculated in step S204 (step S205). Specifically, when the time unit of the extreme value interval calculated from the selected observation signal is second, the signal processing unit 70 divides (divides) 60 by the extreme value interval to obtain a pulse rate per minute. Convert to. Next, the signal processing unit 70 displays or displays the calculated pulse rate on the display unit 80 with numerical information, image information, or the like (step S206). Next, when the pulse rate measurement is continued, the process returns to step S201. On the other hand, when the measurement is not continued (when terminated), the operation pulse wave measurement operation is terminated (step S207).

  In step S203, the method of selecting one observation signal with the largest amplitude from the plurality of pulse wave observation signals acquired at each observation site has been described. However, the present invention is not limited to this. It is not something. In the biological information detection method according to the present invention, for example, an extreme value interval is calculated for each of a plurality of observation signals and converted to a pulse rate, and finally an average value, a median value, etc. are obtained for the plurality of pulse rates. Alternatively, it may be provided to the user US.

  On the other hand, if it is determined in step S202 that the amplitude of each acquired acceleration signal in the three-axis direction is larger than the threshold value, it is determined that this observation signal is affected by body motion noise (acceleration). Then, the following process for reducing the influence of body movement noise is executed. Specifically, first, the signal processing unit 70 selects an observation signal that most closely approximates the amplitude of the stationary observation signal from among the plurality of pulse wave observation signals acquired in step S201. Considering that the pulse wave signal has the least influence (determination), the observation signal is selected (step S208). By such observation signal selection processing, it is possible to reduce the risk that the pulse wave signal has almost disappeared due to body motion noise. In other words, it is possible to avoid a state in which the pulse wave signal is drowned out by body motion noise and cannot be discriminated. Here, the observation signal selected in step S208 is indicated by a solid line in FIG. 9A, for example, and has a signal waveform in which a pulse wave component and a body motion noise component are mixed. In FIG. 9A, a dotted line indicates a pulse wave signal that does not include body motion noise or can substantially ignore body motion noise (for example, an observation acquired by the above-described stationary pulse wave measurement operation). Signal; hereinafter referred to as “reference pulse wave signal”). Here, in the case of the observation signal (solid line) shown in FIG. 9A, the phase is shifted from the phase of the reference pulse wave signal due to the influence of body motion noise.

  Next, in step S208, the signal processing unit 70 determines the time difference until the influence of the acceleration due to the motion appears in the synthesized waveform of the acceleration signal and the pulse wave observation signal selected from the time when the motion of the user US occurs. A time lag / rotation angle estimation process for estimating (time lag) and a rotation angle corresponding to an angle difference between the main blood flow direction of the observation site and the axial direction of the acceleration signal is executed (step S300).

FIG. 10 is a flowchart showing a time lag / rotation angle estimation process executed in the operation pulse wave measurement operation according to the present embodiment. FIG. 11 is a conceptual diagram for explaining the three-axis directions defined in the operation pulse wave measurement operation according to the present embodiment, and FIG. 12 is calculated by the time lag / rotation angle estimation processing according to the present embodiment. FIG. 13 is a diagram illustrating an example of the transition of the rotation angle and the maximum value acquired by the time lag / rotation angle estimation process according to the present embodiment.
First, acceleration signal synthesis will be described. The combined acceleration signal in consideration of the above time lag can be calculated using the following formula (1).

  Here, A (t) is a composite acceleration signal, Ax, Ay, and Az are acceleration signals in the x-axis direction, y-axis direction, and z-axis direction, respectively, and t represents time. Further, c1, c2, and c3 are proportional coefficients applied to the acceleration signals Ax, Ay, and Az, respectively, and are coefficients that set the amplitude of the combined acceleration signal A (t). D1, d2, and d3 represent time differences (time lags) until the influence of the acceleration signals Ax, Ay, and Az appear in the pulse wave observation signal, respectively. Here, for example, as shown in FIG. 11, the x-axis, y-axis, and z-axis are orthogonal to the x-axis direction, with the major axis direction of the wrist USh (arm extension direction; left-right direction in the drawing) as the x-axis direction. The minor axis direction of the wrist USh (arm width direction; upper left and lower right direction in the drawing) is defined as the y-axis direction, and the front and back directions (vertical direction in the drawing) perpendicular to the x and y axis directions are defined as the z-axis direction. That is, the x axis and the y axis are defined in a direction along the skin surface SF of the wrist USh.

  The synthesized acceleration signal A (t) obtained by synthesizing the acceleration signals in the x, y, and z directions defined in FIG. 11 can be calculated in principle using the above equation (1). However, as a result of various verifications, the inventor of the present application has found that the acceleration signal Az in the z-axis direction has little influence on the pulse wave signal, and the time lags d1, d2, and d3 have substantially the same values with little dependence on the axial direction. In addition, the composite acceleration signal A (t) is calculated by rotating the acceleration signal Ax in the x-axis direction and the acceleration signal Ay in the y-axis direction. We found that a value was obtained. Here, the reason that the ratio of the coefficient of the acceleration signal in the x-axis direction and the y-axis direction can be defined by the rotation of the axis is that among a plurality of arteries and capillaries existing under the observation site (under the skin surface SF) The main blood flow direction (that is, the extending direction of the blood vessel VS shown in FIG. 11) is considered to be different for each observation site. That is, the rotation angle θ shown in FIG. 11 corresponds to the angle difference between the main blood flow direction of the observation site and the axial direction of the acceleration signal (x-axis direction in FIG. 11). Based on the result of such verification, the combined acceleration signal A (t) in the triaxial direction shown in the above formula (1) can be calculated using the following formula (2).

  Then, the time lag / rotation angle estimation process executed in step S300 is the value of the time lag d with the proportional coefficient c applied to the acceleration signals Ax, Ay fixed to c = 1 in the above equation (2). And the value of the rotation angle θ of the acceleration signals Ax and Ay is estimated.

  In the time lag / rotation angle estimation process, as shown in FIG. 10, first, the signal processing unit 70 sets the rotation angle θ of the acceleration signal with respect to the x-axis direction (x-axis) and the y-axis direction (y-axis) ( Step S301). The rotation angle θ is sequentially updated by a predetermined angle within a range of −90 ° (= −π / 2) to + 90 ° (= π / 2) every time a series of processes (steps S301 to S305) described later is repeated. (Increase or decrease) and the optimum rotation angle θ is searched. Here, in order to simplify the description, as an example of an initial value, a case where the rotation angle θ is set to 0 ° and the angle is sequentially increased from 0 ° to + 90 ° at predetermined intervals is shown. Further, the signal processing unit 70 sets a state in which no time lag occurs (that is, time lag d = 0) as an initial state.

  Next, the signal processing unit 70 uses the above equation (2) based on the rotation angle θ (= 0 °), the proportional coefficient c = 1, and the time lag d = 0 set as initial values to accelerate in the x-axis direction. The signal Ax (t) and the acceleration signal Ay (t) in the y-axis direction are synthesized (step S302). Here, the resultant acceleration signal A (t) generated in step S302 has a signal waveform as shown by a solid line in FIG. 9B, for example. In FIG. 9B, the dotted line is the reference pulse wave signal.

  Next, the signal processing unit 70 calculates a normalized cross-correlation coefficient with respect to the time lag d based on the observation signal selected in Step S208 and the combined acceleration signal A (t) generated in Step S302 (Step S208). S303). The normalized cross-correlation coefficient calculated in step S303 is shown, for example, in FIG. Here, based on the causal relationship that, as a result of the occurrence of an acceleration during the operation of the user US, it affects the pulse wave observation signal, the signal processing unit 70 performs the normalized mutual phase relationship shown in FIG. In the number, the time lag is sequentially updated at predetermined intervals in the direction in which the causal relationship is established (in the case of FIG. 12, the time lag is a positive direction from 0), and the position where the correlation coefficient first reaches the maximum value Dmax is searched. Then, the time lag d at that position is extracted and stored in a predetermined storage area of the memory unit 60 (step S304). In FIG. 12, the position where the maximum value Dmax is obtained is indicated by a bold line. Here, in the normalized cross-correlation coefficient shown in FIG. 12, the range in which the time lag d is extracted is, for example, when the value of the time lag d is sequentially increased and the correlation coefficient reaches the maximum value Dmax. The process may be terminated, or the value of the time lag d is specified to be a specific time, for example, 1 second or more, and the normalized cross-correlation coefficient is calculated until that time, The maximum value Dmax of the correlation coefficient may be obtained.

  Next, it is determined whether or not the maximum value of the current correlation coefficient calculated in step S304 is smaller than the previously calculated maximum value (step S305). Specifically, the signal processing unit 70 reads the local maximum value of the current and previous correlation coefficients from the memory unit 60, and the current local maximum value is smaller than the previous local maximum value (or the previous local maximum value is the current local maximum value). If it is determined that the time lag is greater than the value, the time lag d at the position of the previous maximum value and the previous rotation angle θ are stored (recorded) in a predetermined storage area of the memory unit 60 (step S306), and the time lag is determined.・ End the rotation angle estimation process.

  On the other hand, in step S305, when the signal processing unit 70 determines that the maximum value of the current correlation coefficient is greater than or equal to the previous maximum value, the time lag d at the position of the current maximum value and the current rotation angle are determined. After saving θ in a predetermined storage area of the memory unit 60, the process returns to step S301 to reset the rotation angle θ, and the above-described series of search processing (steps S301 to S305) is executed again. In step S305, in the case of the first determination process, there is no previous maximum value. In this case, after returning to step S301 unconditionally and resetting the rotation angle θ, the series described above is performed. The search process (steps S301 to S305) is executed again.

  In addition, as a result of verification by the inventor of the present application, it was found that the maximum value of the correlation coefficient was unimodal with respect to the change in the rotation angle θ. However, the present invention is not limited to this. For example, the normalized cross-correlation coefficient is calculated for all rotation angles θ within the range of −90 ° to + 90 °, and the position where the maximum value of the correlation coefficient is the maximum (Pmax in the figure). The time lag d and the rotation angle θ at that time may be selected and stored in the memory unit 60. When such a method is applied, the relationship (transition) between the rotation angle θ and the maximum value of the correlation coefficient is, for example, as shown in FIG.

  Further, in the present embodiment, the case where the rotation angle θ is updated within the range of 180 ° from −90 ° to + 90 ° has been described, but the present invention is not limited to this, and at least What is necessary is just to have the range of 180 degrees, for example, you may make 360 degrees (entire circumference) into a setting range.

  Next, the signal processing unit 70 estimates a proportional coefficient for setting the amplitude of the composite acceleration signal based on the time lag d and the rotation angle θ estimated in the time lag / rotation angle estimation process described above, and performs the operation of the user US. An amplitude estimation process for generating a differential signal approximating a true pulse wave signal from which the influence of the resulting body motion noise has been removed is executed (step S400). That is, in the amplitude estimation process, the proportional coefficient c applied to the acceleration signals Ax and Ay in the x and y directions is estimated as a coefficient for setting the amplitude of the combined acceleration signal A (t) in the above equation (2). Execute the process.

FIG. 14 is a flowchart showing an amplitude estimation process executed in the operation pulse wave measurement operation according to the present embodiment.
In the amplitude estimation process, as shown in FIG. 14, first, the signal processing unit 70 sets the proportional coefficient c applied to the acceleration signals Ax and Ay in the x and y directions in the above equation (2) (step). S401). Here, first, in the above formula (2), the time lag d estimated in the above-described time lag / rotation angle estimation processing and the value of the rotation angle θ of the acceleration signal are applied, and the composition when the proportional coefficient c is set to 1 The amplitude of the acceleration signal A (t) is calculated. Then, the amplitude of the resultant acceleration signal A (t) is compared with the amplitude of the pulse wave observation signal selected in step S208, and the amplitude of the resultant acceleration signal A (t) becomes equal to the amplitude of the observation signal. The value of the proportional coefficient c is calculated as the initial value of the proportional coefficient c, and the proportional coefficient c is set to this initial value.

  Next, the signal processing unit 70 uses the mathematical expression (2) based on the set proportionality coefficient c, the time lag d estimated in the time lag / rotation angle estimation process described above, and the value of the rotation angle θ of the acceleration signal. A composite acceleration signal A (t) is generated (step S402). Next, the signal processing unit 70 takes the difference between the pulse wave observation signal selected in step S208 and the combined acceleration signal A (t) generated in step S402, and generates a difference signal (step S403). .

  Next, the signal processing unit 70 calculates the amplitude of the generated differential signal (step S404), and the amplitude of the stationary pulse wave observation signal acquired in the above-described stationary pulse wave measurement operation and the amplitude of the differential signal. It is determined whether or not the absolute value of the difference is smaller than a predetermined threshold value (step S405). When the signal processing unit 70 determines that the absolute value is smaller than the threshold value, the signal processing unit 70 stores (records) the value of the proportional coefficient c at this time in a predetermined storage area of the memory unit 60 (step S406). The amplitude estimation process is terminated.

  On the other hand, in step S405, when the signal processing unit 70 determines that the absolute value is equal to or greater than the threshold value, the signal processing unit 70 resets the value of the proportional coefficient c to another value and updates it (step S407). Returning to step S402, the above-described series of processing (steps S402 to S405) is executed again. Here, the value of the proportional coefficient c to be reset is sequentially increased or decreased at a predetermined interval.

  Here, the differential signal generated in the process of generating the differential signal (step S403) has a signal waveform as indicated by a solid line in FIG. 9C, for example. In FIG. 9C, the dotted line is the reference pulse wave signal. Here, FIG. 9C shows a signal waveform that substantially matches the phase of the reference pulse wave signal as the differential signal by executing a series of processing of the time lag / rotation angle estimation processing and amplitude estimation processing described above. The obtained case is shown.

  In the amplitude estimation process described above, a method for determining whether or not to repeat a series of processes based on the amplitude of the observation signal at rest is applied, but the present invention is not limited to this. For example, when it is considered that the amplitude of body motion noise is sufficiently larger than the amplitude of the pulse wave signal, the value of the proportional coefficient c is sequentially updated to search for the minimum value of the amplitude of the difference signal, Based on this, a method for determining whether or not to repeat a series of processes may be applied.

  Next, after the time lag / rotation angle estimation process (step S300) and the amplitude estimation process (step S400) are completed, the signal processing unit 70 regards the generated differential signal as a pulse wave signal, as shown in FIG. The extreme value interval is calculated (step S209). Note that the extreme value interval calculation operation in step S209 may be performed on a waveform at an arbitrary time among the waveforms included in the generated difference signal, as in step S204 described above. Then, the average value may be extracted from a plurality of extreme value intervals calculated for a plurality of waveforms (average value) or a distribution of a plurality of extreme value intervals. Next, based on the extreme value interval calculated in step S209, the pulse rate for one minute is calculated (step S205) and displayed on the display unit 80, thereby providing or notifying the user US (step). S206).

  As described above, in the present embodiment, the pulse rate is calculated by removing the body motion noise component caused by the motion from the pulse wave observation signal acquired during the motion of the user US by the photoelectric pulse wave method. When the amplitude of the acceleration signal in the three-axis direction acquired during exercise exceeds a predetermined threshold value, a specific direction along the body surface from the pulse wave observation signal (the xy plane including the x-axis and the y-axis) The pulse rate is calculated using a signal (difference signal) from which the acceleration component of the rotation angle θ) is removed. Here, in the present embodiment, when obtaining an acceleration component to be removed from the pulse wave observation signal, a time difference (time lag d) from the pulse wave observation signal, a coefficient (proportional coefficient c) for determining the amplitude, A method of estimating three parameters of the rotation angle θ of the direction acceleration is applied.

  In the present embodiment, the measurement region has a configuration in which a plurality of light emitting elements and light receiving elements are arranged, and multipoint observation is performed to measure pulse waves at a plurality of different observation sites in the measurement region. When the amplitude of the acceleration signal in the three-axis direction acquired sometimes exceeds a predetermined threshold value, the pulse wave observation signal at the observation site with less influence of body motion noise is selected again to calculate the pulse rate. Here, for the selection of the observation signal, a method of selecting an observation signal having the smallest influence of body motion noise is applied based on the amplitude of the observation signal acquired at each observation part at rest.

  As described above, in this embodiment, by removing the acceleration signal calculated based on the newly estimated parameter from the observation signal of the pulse wave during movement, the same phase as that of the true (original) pulse wave signal is obtained. Since a signal (difference signal) can be acquired, an instantaneous pulse during exercise can be accurately measured.

<Second Embodiment>
Next, a second embodiment of the biological information detection apparatus according to the present invention will be described. Here, configurations and operations equivalent to those of the first embodiment will be described with reference to the above-described drawings as appropriate.

  In the first embodiment described above, as shown in FIG. 2, at least one of the light emitting elements and the light receiving elements arranged in the measurement region MS of the biological information detecting apparatus 100 is arranged in plural. A case has been described in which an optimal observation signal is selected from a plurality of pulse wave observation signals obtained by multipoint observation. In the second embodiment, there is a configuration in which only one light emitting element and one light receiving element are disposed in the measurement region MS, and only one pulse wave observation signal is acquired from one observation site (one point). Observation).

  FIG. 15 is a schematic diagram illustrating a configuration example of a measurement surface of the biological information detection apparatus according to the second embodiment. FIG. 15A is a schematic diagram illustrating an arrangement example of light emitting elements and light receiving elements, and FIG. 15B is a conceptual diagram illustrating an observation site of a pulse wave.

  The biological information detection apparatus according to the second embodiment has a configuration shown in FIG. 15A in the configuration shown in the first embodiment described above (see FIG. 1). Each has a configuration in which one light emitting element E1 and light receiving element R1 are arranged. That is, in this embodiment, the light emitting elements and the light receiving elements are arranged in a one-to-one relationship. In the configuration of the living body information detection apparatus shown in FIG. 3, the light emission control unit 15 causes the light emitting element E1 to emit light with a predetermined light emission intensity as shown in FIG. Pm11 is irradiated with light, and the light scattered by the blood in the blood vessel near the skin surface SF is received by the light receiving element R1 as reflected light. Thereby, the observation signal of the pulse wave in the observation part Pm11 of the skin surface SF is acquired.

Next, the biological information detection method according to the present embodiment will be described. Here, operations and processes equivalent to those of the first embodiment will be described with reference to the above-described drawings as appropriate.
In the biological information detection method according to the present embodiment, the stationary pulse wave measurement operation and the operational pulse wave measurement operation are executed as in the first embodiment described above.

  First, in the stationary pulse wave measurement operation according to the present embodiment, in the flowchart of FIG. 4 shown in the first embodiment, after prompting the user US to stop, the light emitting element E1 is caused to emit light and the reflected light is emitted. Is received by the light receiving element R1, and a pulse wave observation signal and an acceleration signal in a stationary state are acquired for a predetermined time (step S101). Here, in the present embodiment, since the light emitting elements and the light receiving elements are arranged in a one-to-one relationship, an observation signal of one pulse wave from one observation part Pm11 is obtained in this step S101. Only acquired (single point observation). Then, when it is determined that the amplitude of the acceleration signal measured at the time of acquisition of the observation signal is equal to or less than a predetermined threshold and the user US is in a stationary state or a resting state (step S102), the acquisition is performed in step S101. The average value of the amplitudes of the observed pulse wave signals is stored in the stationary pulse wave amplitude recording unit 65 as the amplitude of the stationary observation signal (step S103). In addition, when the amplitude of the acceleration signal measured at the time of acquisition of the observation signal is larger than a predetermined threshold, it is determined that the user US is not in a stationary state or a resting state, and the same as in the first embodiment described above. After performing the operations of steps S104 and S105, the series of processes (steps S101 to S105) described above are executed again.

FIG. 16 is a flowchart showing an operation pulse wave measurement operation executed in the biological information detection method according to the present embodiment.
In the operation pulse wave measurement operation according to the present embodiment, the observation signal selection processing in steps S203 and S208 is omitted in the flowchart of FIG. 7 shown in the first embodiment. That is, in the operation pulse wave measurement operation according to the present embodiment, as shown in the flowchart of FIG. 16, the pulse wave observation signal and the acceleration signal in the motion state of the user US are acquired for a certain time (step S211). Also in this step S211, only the observation signal of one pulse wave is acquired by one point observation. Then, when it is determined that the amplitude of the acceleration signal measured at the time of acquisition of the observation signal is equal to or smaller than a predetermined threshold (step S212), the pulse wave observation signal acquired in step S211 is favorably converted to a pulse wave. Is measured as a pulse wave signal, and the extreme value interval of the observed signal is calculated (step S213). Next, based on the extreme value interval calculated in step S213, the pulse rate for one minute is calculated (step S214), and displayed or displayed on the display unit 80 to be provided or notified to the user US (step S215).

  On the other hand, when it is determined in step S212 that the amplitude of the acquired acceleration signal is larger than the threshold value, the synthesized acceleration signal A (t) and the pulse wave are observed as in the first embodiment described above. Time lag / rotation angle estimation processing for estimating a time lag until the influence of acceleration appears in the signal and a rotation angle corresponding to an angle difference between the main blood flow direction of the observation region and the axial direction of the acceleration signal (step S300) ) And amplitude estimation processing (step S400) for generating a differential signal approximating a true pulse wave signal from which the influence of body motion noise has been removed. Then, the difference signal generated by the series of processes of steps S300 and S400 is regarded as a pulse wave signal, and the extreme value interval is calculated (step S217). Next, based on the extreme value interval calculated in step S217, the pulse rate for 1 minute is calculated (step S214), and displayed or displayed on the display unit 80 to be provided or notified to the user US (step S215). Then, when continuing to measure the pulse rate, the above-described series of processing (steps S211 to S217) is executed again.

  As described above, also in the present embodiment, as in the first embodiment described above, the time difference (time lag d) and amplitude from the pulse wave observation signal newly estimated from the pulse wave observation signal during exercise are newly estimated. The same phase as the true (original) pulse wave signal is obtained by removing the acceleration signal calculated based on the three parameters of the coefficient (proportional coefficient c) that determines the magnitude of the axis and the rotation angle θ of the acceleration signal in each axial direction. Signal (difference signal) can be acquired, and based on this, the instantaneous pulse during exercise can be measured relatively accurately. Here, in the present embodiment, one light-emitting element and one light-receiving element are arranged in the measurement region, and single-point observation that measures pulse waves at one observation site is applied. Based on the observation signal of one pulse wave, it is possible to measure an instantaneous pulse during exercise with simple processing.

  In each of the above-described embodiments, the biological information detection device 100 has a wristwatch shape, and the device main body 101 including the measurement region MS is mounted so as to be in close contact with the back side of the user US wrist USh. However, it may be attached so as to be in close contact with the palm side. Here, as shown in the above-described embodiment, when worn on the back side of the wrist, compared to when worn on the palm side, the worn state (skin surface of the measurement region) due to the lifting of the muscles of the wrist, etc. The pulse wave observation signal can be obtained well without being affected by the change in the close contact state.

  Further, in each of the above-described embodiments, the case where the biological information detection device 100 has a wristwatch shape and is worn on the wrist USh of the user US has been described, but the present invention is not limited to this. . That is, according to the present invention, a biological information detection device in which light emitting elements and light receiving elements are arranged in a predetermined pattern in a measurement region MS is attached in close contact with a part where a pulse wave during operation of a human body can be observed. For example, it may have a shape to be attached by wrapping or sandwiching the observation part such as the wrist part or the upper arm part such as the wrist or the upper arm, the finger part excluding the fingertip, the earlobe, or the ankle, for example. Good.

As mentioned above, although some embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It includes the invention described in the claim, and its equivalent range.
Hereinafter, the invention described in the scope of claims of the present application will be appended.

(Appendix)
[1]
A detection unit that outputs an observation signal detected based on a pulse wave of a user's observation site;
An acceleration measuring unit that outputs a plurality of acceleration signals corresponding to each of a plurality of preset axial directions that are measured in accordance with the user's operation;
The plurality of acceleration signals are synthesized based on a plurality of parameters, and the observation is performed based on the user's operation from a plurality of different synthesized acceleration signals when the values of the parameters are set to a plurality of different values. A parameter estimator for estimating a specific composite acceleration signal corresponding to the acceleration component included in the signal;
A pulse rate calculation unit that calculates the pulse rate of the user from a difference signal obtained by removing the specific synthesized acceleration signal from the observation signal;
The parameter estimation unit estimates a specific value of each parameter corresponding to the specific synthetic acceleration signal based on a value of a cross-correlation coefficient between the plurality of synthetic acceleration signals and the observation signal. Thus, the biological information detection apparatus is characterized in that the specific synthesized acceleration signal is estimated.

[2]
The parameter estimation unit obtains a value of the cross-correlation coefficient for each of the plurality of combined acceleration signals, and sets the value of each parameter when the value of the cross-correlation coefficient is a maximum as the specific value. The biological information detecting device according to [1], wherein the biological information detecting device is estimated.

[3]
The plurality of parameters include a first parameter corresponding to a time difference from the time when the user's motion occurs until an influence of the motion occurs on the observation signal, the axial direction of each acceleration signal, and the observation site. A second parameter corresponding to the angular difference from the main blood flow direction,
[1] or [2], wherein the parameter estimation unit estimates a specific value of the first parameter and a specific value of the second parameter as the specific value. It is a biometric information detection apparatus of description.

[4]
In a stationary state in which the user is not operating, the storage unit stores the amplitude value of the observation signal detected by the detection unit as a stationary amplitude,
The plurality of parameters include a third parameter as a proportional coefficient that sets an amplitude of the combined acceleration signal,
The parameter estimation unit determines a specific value of the third parameter as the specific value based on a comparison between the stationary amplitude and an amplitude of a difference signal between the observation signal and the combined acceleration signal. The biological information detecting device according to [3], wherein the biological information detecting device is estimated.

[5]
The acceleration measuring unit has three axes, an x-axis and a y-axis in a direction orthogonal to each other along a body surface of the observation site of the user, and a z-axis in a direction orthogonal to the x-axis and the y-axis. Are the plurality of axial directions, and the first acceleration signal in the x-axis direction, the second acceleration signal in the y-axis direction, and the third acceleration signal in the z-axis direction are acquired as the plurality of acceleration signals. And
The said parameter estimation part is a biological information detection apparatus as described in [4] characterized by estimating the specific value of each said parameter at least with respect to said 1st acceleration signal and said 2nd acceleration signal.

[6]
The detector includes a light emitting unit that emits light to the observation site of the user, and a light receiving unit that receives the light emitted from the light emitting unit and reflected by the observation site, and outputs the observation signal The biological information detection apparatus according to any one of [1] to [5], wherein the observation signal is detected for at least one observation part of the user.

[7]
The light emitting unit includes one or more light emitting elements that emit light, the light receiving unit includes one or more light receiving elements that receive light, and the light emitting unit and the light receiving unit include at least the light emitting element or the light emitting element. A plurality of any one of the light receiving elements,
The detection unit receives light reflected from a plurality of different observation sites of the user and is received from the light emitting unit by the light receiving unit, and a plurality of the observation signals corresponding to each of the plurality of observation sites An observation signal selection unit that selects a specific observation signal having an amplitude that most closely approximates the stationary amplitude from the plurality of observation signals,
The said parameter estimation part is a biological information detection apparatus as described in [6] characterized by estimating the specific value of these parameters based on the said specific observation signal.

[8]
The observation signal selection unit compares the amplitude of each acceleration signal with a predetermined threshold, and selects the specific observation signal from the plurality of observation signals when the amplitude of each acceleration signal is greater than the threshold. The biological information detecting device according to [7], which is characterized in that

[9]
The biological information detection apparatus according to any one of [1] to [8], further comprising a display unit that displays the pulse rate calculated by the pulse rate calculation unit.

[10]
Acquiring an observation signal based on the pulse wave of the user's observation site, and acquiring a plurality of acceleration signals corresponding to each of a plurality of preset axial directions accompanying the operation of the user,
The plurality of acceleration signals are synthesized based on a plurality of parameters, and the observation is performed based on the user's operation from a plurality of different synthesized acceleration signals when the values of the parameters are set to a plurality of different values. Estimate a specific composite acceleration signal corresponding to the acceleration component contained in the signal,
Calculate the pulse rate of the user from the difference signal obtained by removing the specific synthesized acceleration signal from the observation signal,
The specific synthetic acceleration signal is estimated based on a value of a cross-correlation coefficient between the plurality of synthetic acceleration signals and the observation signal, and a specific value of each parameter corresponding to the specific synthetic acceleration signal is estimated. It is the biological information detection method characterized by performing by this.

[11]
The plurality of parameters include a first parameter corresponding to a time difference from the time when the user's motion occurs until an influence of the motion occurs on the observation signal, the axial direction of each acceleration signal, and the observation site. A second parameter corresponding to the angular difference from the main blood flow direction,
The biological information detection method according to [10], wherein a specific value of the first parameter and a specific value of the second parameter are estimated as specific values of the plurality of parameters. It is.

[12]
The plurality of parameters include a third parameter as a proportional coefficient that sets an amplitude of the combined acceleration signal,
Storing the value of the amplitude of the observed signal detected in a stationary state where the user is not operating as a stationary amplitude,
As the specific values of the plurality of parameters, the specific value of the third parameter is estimated based on a comparison between the stationary amplitude and the amplitude of the difference signal between the observation signal and the combined acceleration signal. The biological information detection method according to [11], which is characterized in that

[13]
On the computer,
Acquiring an observation signal based on the pulse wave of the user's observation site, and acquiring a plurality of acceleration signals corresponding to each of a plurality of preset axial directions accompanying the operation of the user,
The plurality of acceleration signals are synthesized based on a plurality of parameters, and the observation is performed based on the user's operation from a plurality of different synthesized acceleration signals when the values of the parameters are set to a plurality of different values. Let us estimate a specific composite acceleration signal corresponding to the acceleration component contained in the signal,
The pulse rate of the user is calculated from the difference signal obtained by removing the specific synthesized acceleration signal from the observation signal,
The specific synthetic acceleration signal is estimated based on a value of a cross-correlation coefficient between the plurality of synthetic acceleration signals and the observation signal, and a specific value of each parameter corresponding to the specific synthetic acceleration signal is estimated. It is a biological information detection program characterized by being performed by this.

[14]
The plurality of parameters include a first parameter corresponding to a time difference from the time when the user's motion occurs until an influence of the motion occurs on the observation signal, the axial direction of each acceleration signal, and the observation site. A second parameter corresponding to the angular difference from the main blood flow direction,
In the computer,
The biological information detection program according to [13], wherein a specific value of the first parameter and a specific value of the second parameter are estimated as specific values of the plurality of parameters. It is.

[15]
The plurality of parameters include a third parameter as a proportional coefficient that sets an amplitude of the combined acceleration signal,
In the computer,
Storing the value of the amplitude of the observed signal detected in a stationary state where the user is not operating as a stationary amplitude,
As a specific value of the plurality of parameters, a specific value of the third parameter is estimated based on a comparison between the stationary amplitude and an amplitude of a difference signal between the observation signal and the synthesized acceleration signal. The biological information detection program according to [14], which is characterized in that

10 Light emitter (detector)
15 Light emission control unit 20 Light receiving unit (detection unit)
30 Acceleration measurement unit 40 Signal amplification unit 60 Memory unit 65 Stationary pulse wave amplitude recording unit (storage unit)
70 Signal processing unit (observation signal selection unit, parameter estimation unit, pulse rate calculation unit)
80 Display Unit 100 Biological Information Detection Device 101 Device Main Body US User USh Wrist SF Skin Surface MS Measurement Area E1-E9 Light-Emitting Element R1-R4 Light-Receiving Element Pm Observation Site

Claims (18)

A detection unit that outputs an observation signal detected based on a pulse wave of at least one observation part of the user;
An acceleration measuring unit that outputs at least one acceleration signal corresponding to at least one axial direction, which is measured in accordance with the user's movement;
Based on a comparison between the observed acceleration signal and a synthesized acceleration signal obtained by synthesizing the acceleration signal based on at least one parameter, a specific parameter of the parameter corresponding to an acceleration component corresponding to the user's action in the observation signal A parameter estimator for estimating the value;
A pulse rate calculation unit that calculates the pulse rate of the user as biological information from a difference signal obtained by removing a specific synthesized acceleration signal corresponding to the specific value of the parameter from the observation signal;
A biological information detection device comprising:   The parameter estimation unit, based on the values of the cross-correlation coefficients between the plurality of different synthetic acceleration signals and the observed signal when the parameter values are set to a plurality of different values, The biological information detection apparatus according to claim 1, wherein a specific value is estimated.   The parameter estimation unit acquires the value of the cross-correlation coefficient for each of the plurality of combined acceleration signals, and estimates the value of the parameter when the value of the cross-correlation coefficient is a maximum as the specific value The biological information detecting apparatus according to claim 2, wherein The parameter includes a first parameter corresponding to a time difference from the time when the user's movement occurs until the influence of the movement occurs on the observation signal, and the main axis direction of each acceleration signal and the main part of the observation portion. A second parameter corresponding to the angular difference with the blood flow direction,
The parameter estimation unit estimates a specific value of the first parameter and a specific value of the second parameter as the specific value, respectively. The biological information detection apparatus according to 1. In a stationary state in which the user is not operating, the storage unit stores the amplitude value of the observation signal detected by the detection unit as a stationary amplitude,
The parameter includes a third parameter as a proportional coefficient for setting the amplitude of the composite acceleration signal,
The parameter estimation unit is configured to use a specific value of the third parameter as the specific value based on a comparison between the stationary amplitude and the amplitude of the difference signal between the observation signal and the combined acceleration signal. The biological information detecting device according to claim 4, wherein the biological information detecting device is estimated. The detection unit outputs a plurality of the observation signals based on pulse waves of a plurality of the observation parts different from each other of the user,
The biological information detection device includes an observation signal selection unit that selects a specific observation signal having an amplitude that most closely approximates the stationary amplitude from the plurality of observation signals,
The biological information detection apparatus according to claim 5, wherein the parameter estimation unit estimates the specific value of the parameter based on the specific observation signal.   The observation signal selecting unit compares the amplitude of the acceleration signal with a predetermined threshold value, and selects the specific observation signal from the plurality of observation signals when the amplitude of the acceleration signal is larger than the threshold value. The living body information detecting device according to claim 6 characterized by things. The detection unit receives a light emitted from the light emitting unit and reflected from the observation part, and outputs the observation signal. A light receiving portion,
The light emitting unit includes one or more light emitting elements that emit light,
The light receiving unit includes one or more light receiving elements for receiving light,
The biological information detection apparatus according to claim 1, wherein the light emitting unit and the light receiving unit include at least one of the light emitting element and the light receiving element.   The biological information detection apparatus according to claim 1, further comprising a display unit that displays the pulse rate calculated by the pulse rate calculation unit. Acquiring an observation signal based on a pulse wave of at least one observation part of the user, and acquiring at least one acceleration signal corresponding to at least one axial direction associated with the user's movement,
Identification of each parameter corresponding to an acceleration component corresponding to the user's action in the observation signal based on a comparison between the observation signal and the synthesized acceleration signal obtained by synthesizing the acceleration signal based on at least one parameter Estimate the value of
A biological information detection method, wherein the pulse rate of the user is calculated as biological information from a difference signal obtained by removing a specific synthetic acceleration signal corresponding to the specific value of the parameter from the observation signal.   The estimation of the specific value of the parameter is based on a value of a cross-correlation coefficient between a plurality of different synthesized acceleration signals and the observed signal when the parameter value is set to a plurality of different values. The biological information detection method according to claim 10, wherein the biological information detection method is performed.   In the estimation of the specific value of the parameter, the value of the cross-correlation coefficient for each of the plurality of combined acceleration signals is obtained, and the value of the parameter when the value of the cross-correlation coefficient is maximized, The biological information detection method according to claim 11, wherein the specific value of the parameter is estimated. The parameter includes a first parameter corresponding to a time difference from the time when the user's movement occurs until the influence of the movement occurs on the observation signal, and the main axis direction of each acceleration signal and the main part of the observation portion. A second parameter corresponding to the angular difference with the blood flow direction,
The biological value according to any one of claims 10 to 12, wherein the specific value of the first parameter and the specific value of the second parameter are estimated as the specific value of the parameter. Information detection method. The parameter includes a third parameter as a proportional coefficient for setting the amplitude of the composite acceleration signal,
Storing the value of the amplitude of the observed signal detected in a stationary state where the user is not operating as a stationary amplitude,
As the specific value of the plurality of parameters, the specific value of the third parameter is estimated based on a comparison between the stationary amplitude and the amplitude of the difference signal between the observed signal and the synthesized acceleration signal The biological information detection method according to claim 13, wherein: On the computer,
The observation signal is acquired from a detection unit that outputs an observation signal based on a pulse wave of at least one observation region of the user, and at least one corresponding to each of at least one axial direction associated with the operation of the user The acceleration signal is acquired from the acceleration measurement unit that outputs the acceleration signal,
Based on a comparison between the observed acceleration signal and a combined acceleration signal obtained by synthesizing the acceleration signal based on at least one parameter, the acceleration signal corresponding to an acceleration component based on the user's action, Estimate a specific value of a parameter,
A biological information detection program for calculating the pulse rate of the user as biological information from a difference signal obtained by removing a specific synthetic acceleration signal corresponding to the specific value of the parameter from the observation signal.   The estimation of the specific value of the parameter is based on a value of a cross-correlation coefficient between a plurality of different synthesized acceleration signals and the observed signal when the parameter value is set to a plurality of different values. The biological information detection program according to claim 15, wherein the biological information detection program is executed. The parameter includes a first parameter corresponding to a time difference from the time when the user's movement occurs until the influence of the movement occurs on the observation signal, and the main axis direction of each acceleration signal and the main part of the observation portion. A second parameter corresponding to the angular difference with the blood flow direction,
In the computer,
The biological information detection program according to claim 15 or 16, wherein the specific value of the first parameter and the specific value of the second parameter are estimated as the specific value of the parameter. . The parameter includes a third parameter as a proportional coefficient for setting the amplitude of the composite acceleration signal,
In the computer,
Storing the value of the amplitude of the observed signal detected in a stationary state where the user is not operating as a stationary amplitude,
As the specific value of the parameter, the specific value of the third parameter is estimated based on a comparison between the amplitude at rest and the amplitude of the difference signal between the observed signal and the combined acceleration signal. The biological information detection program according to claim 17.

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