JP2019170540A - Biometric measurement device and program - Google Patents

Abstract

To provide a technology to switch a measurement condition during measurement.SOLUTION: A measurement device includes: a spectral sensor including spectral means for dispersing a reflection light from a living body at a measurement position or a transmission light that has transmitted the living body at the measurement position according to the wavelength, and light reception means that includes a plurality of pixels, each of the plurality of pixels receiving a light including a predetermined wavelength dispersed by the spectral means; generation means for generating a biological signal from a light reception result of a predetermined pixel of the light reception means; first determination means for determining a cycle of the biological signal; detection means for detecting a feature amount of the biological signal; setting means for setting a living body measurement condition to the spectral sensor; second determination means for determining whether or not the measurement condition needs to be changed on the basis of the biological signal; and third determination means for, when it is determined that a change in the measurement condition is needed in a first cycle of the biological signal, determining whether or not a change in the measurement condition is possible in a period from the detection of the feature amount by the detection means in the first cycle to a time point when the first cycle ends.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a biological measurement apparatus and program.

  2. Description of the Related Art There are known measuring apparatuses that detect biological information by irradiating a part of a living body with light and detecting the amount of reflected light or transmitted light from the living body. The biological information is, for example, various physiological / anatomical information emitted by the living body, such as the pulse rate and the degree of vascular hardening. For example, the pulse rate can be detected based on a pulse wave signal indicating fluctuations in the amount of reflected or transmitted light accompanying blood movement in the blood vessel. For example, the degree of hardening of the blood vessel can be detected based on a feature point of an acceleration pulse wave signal (hereinafter simply referred to as an acceleration signal) obtained by differentiating the pulse wave signal twice.

  Patent Document 1 discloses a pulse wave measurement device that is an example of a biological information measurement device. According to Patent Document 1, the pulse wave measuring device irradiates a fingertip with a light beam, and detects a pulse wave from a temporal variation in the amount of reflected light. In the detection of biological information, if the measurement state of the living body changes after the start of measurement, the measurement accuracy may decrease. Therefore, Patent Document 2 discloses a configuration in which measurement conditions such as a light emission time and a light emission interval are switched when a measurement state of a living body changes during measurement. Patent Document 3 discloses a configuration that reduces the power consumption of the measuring device by switching the operation mode of the light receiving unit based on the timing of the feature point of the detection signal detected by the light receiving unit.

Japanese Patent Laid-Open No. 2004-046767 JP 2010-004972 A JP 2017-108905 A

  When the measurement condition is switched during the detection of the biological information, the detection signal detected by the light receiving unit changes, and it becomes difficult to detect the biological information from the detection signal due to the change in the detection signal. On the other hand, if measurement is interrupted to switch measurement conditions, detection of continuous biological information is interrupted, and the detection time of biological information becomes longer. Patent Document 2 discloses switching measurement conditions, but does not disclose a configuration that avoids the influence of detection signal fluctuations associated therewith. Patent Document 3 discloses a configuration that aims to reduce power consumption, does not switch measurement conditions according to changes in the measurement state of a living body, and avoids the influence of fluctuations in detection signals caused by this switching. Not.

  The present invention provides a technique for switching measurement conditions during measurement.

  According to one aspect of the present invention, the measuring device uses a light source that emits light toward the measurement position, reflected light from the living body at the measurement position, or transmitted light that has passed through the living body at the measurement position. A spectroscopic sensor including a spectroscopic means for performing spectroscopic analysis according to the above, and a plurality of pixels, and each pixel of the plurality of pixels includes a light receiving means for receiving light including a predetermined wavelength spectrally separated by the spectroscopic means, A generation unit that generates a biological signal from a light reception result of a predetermined pixel of the light receiving unit, a first determination unit that determines a cycle of the biological signal, a detection unit that detects a feature amount of the biological signal, and a measurement of the biological body A setting means for setting a condition in the spectroscopic sensor, a second determination means for determining whether or not the measurement condition needs to be changed based on the biological signal, and a change in the measurement condition in the first period of the biological signal. Said second if necessary When the determination means determines, a third determination is made as to whether or not the measurement condition can be changed within a period from when the detection means detects the feature amount in the first cycle to an end time of the first cycle. And a determination unit.

  According to the present invention, measurement conditions can be switched during measurement.

The functional block diagram of the measuring device by one Embodiment. The block diagram of the measuring device by one Embodiment. The figure which shows the spectrum of the white light source by one Embodiment, and the structure of a line sensor. The flowchart of the detection process of the biometric information by one Embodiment. The figure which shows the biomedical signal and acceleration signal by one Embodiment, and a feature point. The flowchart of the change process of the measurement conditions by one Embodiment. Explanatory drawing of the change process of the measurement conditions by one Embodiment. The flowchart of the change process of the measurement conditions by one Embodiment. Explanatory drawing of the change process of the measurement conditions by one Embodiment. The figure which shows the external appearance of the measuring apparatus by one Embodiment.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In addition, the following embodiment is an illustration and does not limit this invention to the content of embodiment. In the following drawings, components that are not necessary for the description of the embodiments are omitted from the drawings.

<First embodiment>
FIG. 10 is a perspective view of the measuring apparatus 1 according to the present embodiment. 10A shows a state where the shutter member 102 covers the opening 500, and FIG. 10B shows a state where the shutter 500 is moved to the retracted position and the opening 500 is exposed. Yes. The opening 500 is covered with a transparent cover 400 that prevents foreign matter from falling into the housing 110. The housing 110 is provided with a groove-shaped guide rail 116 along the X direction in FIG. Further, the guide portion 131 of the guide member 103 is fitted into the guide rail 116. As a result, the guide member 103 and the shutter member 102 can move within the range in which the guide rail 116 is provided in the X direction. A spring is attached to the guide portion 131 of the guide member 103 in the housing 110. The guide member 103 stops at the position shown in FIG. 10A in a state in which no force is applied to the guide member 103 from the outside by the spring force. When the user measures biometric information, the user pushes the finger receiving portion 320 of the guide member 103 in the X direction with a finger, and slides the guide member 103 and the shutter member 102 in the X direction. The measuring apparatus 1 is configured such that when the guide member 103 and the shutter member 102 are pushed by a finger to a position limited by the guide rail 116, the tip portion of the finger covers the opening 500. In this state, the white light source 21 (FIG. 2) irradiates the finger with light from the inside of the housing 110 through the opening 500, and the line sensor 24 (FIG. 2) inside the housing 110 transmits the reflected light. Receive light.

  The housing 110 is provided with a pressing member 105 and a pressing spring 151 that are rotatably held by the bearing portion 119. The pressing spring 151 applies a force toward the opening 500 to the pressing member 105. The pressing member 105 is provided with a pressing rib 152, and the shutter member 102 is provided with a pressed rib 123. In the state of FIG. 10A, the pressing rib 152 contacts the pressed rib 123, and thereby the shutter member 102 is urged against the upper surface of the housing 110. A white reference plate is provided on the surface of the shutter member 102 on the opening 500 side. The white reference plate is used for calibration of the white light source 21 and the line sensor 24 inside the housing 110. The shutter member 102 prevents light from leaking from the housing 110 through the opening 500 during calibration. The pressing member 105 also has a role of stabilizing the measurement target fingertip at the position of the opening 500 at the time of measurement.

  FIG. 2 is a configuration diagram of hardware arranged in the housing 110 of the measuring apparatus 1. The CPU 50 is a control unit that controls the entire measurement apparatus 1. The CPU 50 executes various controls described later based on the program stored in the ROM 51. The CPU 50 stores in the RAM 52 data used when executing various controls and data that needs to be temporarily stored. The CPU 50 can communicate with the ROM 51, the RAM 52, the I / O port 54, the AD conversion circuit 55, and the external communication circuit 56 via the bus 53. The light source drive circuit 60 controls the light emission of the white light source 21. Further, the CPU 50 can control the light emission intensity of the white light source 21 by controlling the light source driving circuit 60 via the I / O port 54. Further, the CPU 50 can set the charge accumulation time of the line sensor 24 via the I / O port 54. As will be described later, the line sensor 24 receives the reflected light of the light emitted from the white light source 21 via the condenser lens 22 and the diffraction grating 23, and outputs a voltage corresponding to the amount of received light to the AD conversion circuit 55. Then, the CPU 50 acquires a voltage corresponding to the amount of received light output from the line sensor 24 via the AD conversion circuit 55. Further, the CPU 50 is configured to be able to communicate with the external device 30 via the external communication circuit 56. The condenser lens 22, the diffraction grating 23, and the line sensor 24 constitute a spectrocolorimeter (spectral sensor). Alternatively, the white light source 21, the condensing lens 22, the diffraction grating 23, and the line sensor 24 constitute a spectroscopic sensor.

  FIG. 1 is a block diagram for explaining the operation of the measuring apparatus 1 in the present embodiment. The CPU 50 executes the program stored in the ROM 51 to cooperate with the I / O port 54, the light source driving circuit 60, the AD conversion circuit 55, the external communication circuit 56, the ROM 51, and the RAM 52, and the control unit 10 in FIG. Function as. The light emission control unit 11 corresponds to the CPU 50 and the light source drive circuit 60, adjusts the light emission intensity of the white light source 21, and controls the light emission of the white light source 21. The white light source 21 has a light emission wavelength distribution over the entire visible light. As the white light source 21, for example, tungsten light, white LED, RGB (red, green, blue) three-color LED, or the like can be used. In the present embodiment, the white light source 21 is a white LED obtained by packaging an LED element that emits blue light with a resin mixed with a yellow fluorescent material. FIG. 3A shows the relative intensity (luminance) for each wavelength of the white light source 21 used in the present embodiment. The peak near the wavelength of 450 nm is the emission spectrum of the blue LED, and the peak near 600 nm is the spectrum of the yellow phosphor. This spectrum is due to the light generated when the fluorescent material receives light from the LED element and fluoresces.

  As shown in FIG. 1, the light 70 emitted from the white light source 21 passes through the opening 500 of the housing 110 at an angle of about 45 degrees with respect to the normal direction, and is the measurement object 90 at the measurement position. Irradiate the fingertip. This irradiation light becomes scattered light 71 corresponding to the light absorption characteristics of the measurement object 90. A part of the scattered light 71 is converted into parallel light 72 by the condenser lens 22 and enters the diffraction grating 23 at an incident angle of 90 degrees. The diffraction grating 23 separates incident light according to the wavelength. The dispersed light 73 dispersed is incident on each pixel of the line sensor 24. Each pixel of the line sensor 24 outputs a voltage corresponding to the received light amount of the incident dispersed light 73 to the received light amount detection unit 12. FIG. 3B is a schematic diagram of the line sensor 24. The line sensor 24 according to the present embodiment has 60 pixels necessary for detecting visible light having a wavelength of about 400 nm to about 700 nm in units of 5 nm. In the present embodiment, the measuring device 1 is adjusted and assembled so that the first pixel of the line sensor 24 detects light including a wavelength of about 400 nm and the # 60 pixel of about 700 nm. The received light amount detection unit 12 corresponds to the CPU 50, the AD conversion circuit 55, and the I / O port 54. In practice, the AD conversion circuit 55 converts the voltage of each pixel output from the line sensor 24 into, for example, a 12-bit digital value, and the CPU 50 performs AD conversion on the digital value indicating the amount of light received by each pixel. Obtained from the circuit 55. The line sensor 24 of the present embodiment is a charge storage type, and outputs a voltage signal for each pixel according to the amount of dispersed light incident during a predetermined storage time. The accumulation time in the line sensor 24 is set in the line sensor 24 via the I / O port 54 by the received light amount detection unit 12, more specifically, the CPU 50.

  The biological signal generation unit 13 generates a biological signal based on a light reception result of a predetermined pixel, that is, a value indicating the amount of received light. In the present embodiment, a living body fingertip is used as a measurement target 90, and a living body signal is generated based on the amount of light received by a 38th pixel that detects light including a wavelength of about 590 nm. This biological signal is also referred to as a fingertip volume pulse wave signal. The wavelength of about 590 nm used for the generation of the biological signal is a wavelength at which the amount of light absorbed by hemoglobin in blood is relatively large.

  The external communication unit 17 corresponds to the external communication circuit 56 and communicates with the external device 30. The external device 30 instructs the measurement apparatus 1 to start measurement and end measurement. In addition, the measuring apparatus 1 transmits a biological signal, a signal obtained by differentiating the biological signal multiple times, a period C of the biological signal, a feature point of the biological signal, and the like to the external device 30. The external device 30 can calculate the pulse value from the cycle C of the biological signal. Furthermore, the external device 30 can determine the degree of hardening of the blood vessel based on each feature point and its value. The external device 30 is, for example, a personal computer or a tablet terminal. The communication with the external device 30 may be wired or wireless. The condition changing unit 14 will be described later.

  FIG. 4 is a flowchart of the biometric information detection process. When the measurement apparatus 1 receives a measurement start instruction from the external device 30, the measurement apparatus 1 determines measurement conditions in S100. The measurement conditions are, for example, the light emission intensity of the white light source 21 and the charge accumulation time (light reception time) of the line sensor 24. For example, the light emission control unit 11 causes the white light source 21 to emit light with a predetermined light emission intensity, and the light reception amount detection unit 12 detects the light reception amount of the 38th pixel used for generating a biological signal for a predetermined period. Then, the control unit 10 determines the light emission intensity of the white light source 21 and / or the line sensor 24 so that the maximum value of the received light amount detected in the predetermined period is near the maximum value of the voltage range detectable by the AD conversion circuit 55. The charge accumulation time is determined and used as a measurement condition. The predetermined period may be one period or more of the fingertip volume pulse wave signal, which is a biological signal to be generated, and may be, for example, 2 seconds. Note that the emission intensity of the white light source 21 for determining the measurement conditions in S100 is determined in advance. The control unit 10 calculates the light emission intensity of the white light source 21 and / or the charge accumulation time of the line sensor 24 based on the light emission intensity and the maximum value of the amount of light received by the 38th pixel. It should be noted that while changing the light emission intensity of the white light source 21 and / or the charge accumulation time of the line sensor 24 for each predetermined period, the light emission intensity of the white light source 21 and / or the charge of the line sensor 24 at which the maximum value of the amount of received light is appropriate. The structure which calculates | requires accumulation | storage time may be sufficient. The control unit 10 sets the determined measurement conditions in the light emission control unit 11 and the received light amount detection unit 12 in S101. Thereby, the light emission control part 11 makes the white light source 21 light-emit with the light emission intensity determined by S100. The received light amount detection unit 12 sets the charge accumulation time determined in S100 in the line sensor 24.

  The biological signal generation unit 13 generates a biological signal based on the amount of light received at each timing of the 38th pixel, and outputs the biological signal to the period calculation unit 15 and the feature calculation unit 16. The biological signal generation unit 13 can generate a biological signal by directly indicating the received light amount at each timing of the 38th pixel in time series. Further, the biological signal generation unit 13 generates a biological signal by dividing the amount of light received at each timing of the 38th pixel into a predetermined number, obtaining an average value of the predetermined number, and indicating the average value in time series. Can do. In addition, the biological signal generation unit 13 can generate a biological signal based on a moving average of the amount of received light at a predetermined number of times of the 38th pixel. In addition, it is possible to perform a filter process on a signal indicating the amount of light received at each timing or an average value thereof in time series, and use the signal after the filter process as a biological signal. The period calculation unit 15 and the feature calculation unit 16 detect a biological signal in S102. In step S103, the cycle calculation unit 15 determines the cycle C of the biological signal based on the extreme value of the biological signal. For example, the period calculation unit 15 determines the period C of the biological signal based on the time interval of the local minimum value of the biological signal. FIG. 5A shows a detection example of a biological signal and a period C (four times of C1 to C4) of the biological signal. Moreover, the period calculation part 15 can also determine the period of a biological signal based on the time interval of the local maximum value of the acceleration signal which differentiated the biological signal twice. FIG. 5B shows a detection example of the period C (four times of C′1 to C′4) of the biological signal determined from the time interval between the acceleration signal and the local maximum value of the acceleration signal.

  In step S104, the feature calculation unit 16 calculates feature points and values of the biological signal. In the present embodiment, the first five of the local maximum value and the local minimum value of the acceleration signal obtained by differentiating the biological signal twice with the start timing of the period C of the biological signal as a base point are feature points. Note that the start timing of the cycle C of the biological signal is the timing of the local minimum value of the biological signal. FIG. 5C shows an example of five feature points a, b, c, d, and e. The feature calculation unit 16 can also use the local maximum value and the local minimum value of the signal obtained by differentiating the biological signal four times as the feature points. More generally, the feature calculation unit 16 can use, as the feature amount, information on a change point of the differential signal obtained by differentiating the biological signal once or more. Further, the number of feature points is not limited to 4, and may be other numbers. In step S <b> 105, the external communication unit 17 outputs the biological signal, the acceleration signal, the period C of the biological signal, the feature point, and its value to the external device 30. In S106, the control unit 10 determines whether a measurement end instruction is received from the external device 30, and repeats the process from S102 until the measurement end instruction is received.

  FIG. 6 is a flowchart of measurement condition change processing performed while the processing from S102 to S105 in FIG. 4 is repeated. In S200, the condition changing unit 14 waits until the cycle calculating unit 15 calculates the cycle C of the biological signal. FIG. 7A shows a state in which the cycle calculation unit 15 detects the end of the cycle C1 of the biological signal at the timing Ta. In the present embodiment, the period calculation unit 15 detects the local minimum value of the biological signal by detecting that the amplitude of the biological signal continuously increases for a predetermined time or more. That is, the period calculation unit 15 detects the end time (the time when the local minimum value is reached) of the period C1 of the biological signal afterwards.

  When detecting the end of the previous cycle of the biological signal at the timing Ta, the condition changing unit 14 calculates the feature point by the feature calculating unit 16 in the current cycle C (cycle C2 in FIG. 7A) in S201. Wait until the end of. In FIG. 7A, the timing when the calculation of the feature points is completed is shown as timing Tb. When the calculation of the feature points is completed, the condition changing unit 14 calculates the time from the start timing of the current period C2 to the end of the calculation of the feature points of the biological signal as the feature point calculation period P in S202. The feature point calculation period P is a period from the end timing of the cycle C1 (start timing of the cycle C2) to the timing Tb. The condition changing unit 14 determines the necessity of changing the measurement conditions in S203. For example, the condition changing unit 14 obtains the peak value M of the biological signal in the feature point calculation period P of the current cycle, and determines that the measurement condition needs to be changed when the peak value M is not within a predetermined range. For example, if the AD conversion circuit 55 has a 12-bit resolution, the predetermined range can be 3800 to 4000, which is near the maximum value that can be detected by the AD conversion circuit 55.

  If the condition changing unit 14 determines that the measurement condition does not need to be changed, the condition changing unit 14 determines in step S207 whether the measurement of the biometric information is completed. If not completed, the process is repeated from step S200. On the other hand, if it is determined that the measurement condition needs to be changed, the condition changing unit 14 determines whether the measurement condition can be changed in S204. In the present embodiment, the condition changing unit 14 estimates the end time of the current cycle C2 as the predicted time CX, and determines that the measurement condition can be changed when the change of the measurement condition is completed by the predicted time CX. On the other hand, when the change of the measurement condition is not completed by the predicted time CX, the condition changing unit 14 determines that the change of the measurement condition is impossible. In the present embodiment, the predicted time CX is set to a time after a period corresponding to the cycle C1 immediately before the start timing of the cycle C2. In addition, it can also be set as the structure which calculates the estimated time CX using the average value of several past periods C instead of the last period C. FIG. Since the cycle of the biological signal varies, the condition changing unit 14 can use the variation margin Z, which is the variation amount of the biological signal, for calculating the predicted time CX. In this case, the condition changing unit 14 sets the time earlier by the variation margin Z as the predicted time CX than the time one cycle before the start timing of the cycle C2 or the time after the average value of the past plural cycles. Note that the value of the fluctuation margin Z is stored in the ROM 51 in advance. In this example, the fluctuation margin Z is set to 100 milliseconds.

  The condition changing unit 14 obtains the total value S1 of the feature point calculation period P and the change time D necessary for changing the measurement condition, and sets the time after the total value S1 as the completion time CP from the start timing of the period C2. To do. Then, the condition changing unit 14 determines that the measurement condition cannot be changed if the completion time CP is later than the predicted time CX, and otherwise determines that the measurement condition can be changed. In other words, the condition changing unit 14 determines whether the change of the measurement condition is completed within the period from the timing Tb when the calculation of the feature amount is completed to the predicted time CX by comparing the period and the change time D. To do. That is, the condition changing unit 14 determines that the measurement condition cannot be changed if the period is shorter than the change time D, and otherwise determines that the measurement condition can be changed. Here, the change time D is the time from when the measurement condition is changed until the biological signal is stabilized, and thus the period and feature point can be determined based on the biological signal. For example, when changing the light emission intensity of the white light source 21, the light emission intensity stabilization wait time is included in the change time D. When the received light amount detection unit 12 has a filter circuit such as a low-pass filter, the time based on the time constant of the filter is included in the change time D. Further, when the biological signal generation unit 13 generates a biological signal by moving average processing of time-series digital values, the time required for the average processing is included in the change time D. In the present embodiment, it is assumed that only the light emission intensity of the white light source 21 is changed during measurement, and the biological signal generation unit 13 generates a biological signal by moving and averaging time-series digital values. In this case, the stabilization wait time of the light emission intensity can be set to 20 milliseconds, the time required for the moving average process can be set to 80 milliseconds, and the change time D can be set to 100 milliseconds, which is the sum of them.

  In addition, in order to detect the local minimum value of the biological signal, when it is necessary to detect a decrease in the amplitude of the biological signal before the local minimum value is reached for a predetermined period, the condition changing unit 14 detects the predetermined period. The time Y can be taken into account in calculating the total value S1. In this case, the condition changing unit 14 determines the completion time CP by obtaining a total value S1 of the feature point calculation period P, the change time D, and the detection time Y. That is, the condition changing unit 14 determines that the measurement condition cannot be changed if the period from the timing Tb at which the calculation of the feature amount is completed to the predicted time CX is shorter than the sum of the change time D and the detection time Y, Otherwise, it is determined that the measurement conditions can be changed.

  Returning to FIG. 6, if it is determined in S204 that the measurement condition can be changed, the condition changing unit 14 calculates a new measurement condition based on the value of the maximum value M of the biological signal in the feature point calculation period P in S205. During measurement in this example, the emission intensity of the white light source 21 is changed, and the charge accumulation time of the line sensor 24 is constant. The method for determining the measurement conditions is the same as that described in S100 of FIG. 4 and will not be described again. The condition changing unit 14 changes the measurement conditions determined in S206. FIG. 7B shows an example of a biological signal when the measurement condition is changed at the timing Tb. FIG. 7C shows an example of the acceleration signal when the measurement condition is changed at the timing Tb. The condition changing unit 14 repeats the processing from S200 until receiving a measurement end instruction from the external device 30.

  For example, the force of pressing the finger that is the measurement target 90 against the transparent cover 400 of the opening 500 and the contact state between the transparent cover 400 and the measurement target 90 can change during the measurement. In this case, the measurement conditions determined at the start of measurement may not be appropriate for the measurement object 90 after the state change. For this reason, in this embodiment, measurement conditions are changed as needed during measurement. Here, in the present embodiment, it is determined whether the measurement condition can be changed after the feature point is calculated in a certain cycle of the biological signal and before the start of the next cycle. If the measurement condition can be changed by the start of the next cycle, the measurement condition is changed. That is, the measurement condition is changed when the measurement condition can be changed in a signal period that is not used for detection of biological information in the biological signal. With this configuration, even when the state of the measurement target 90 changes, the measurement conditions can be changed without interrupting the calculation of the feature points and period of the biological signal.

  For example, No in S204 in FIG. 6 corresponds to the fact that the measurement condition cannot be changed even though it is determined that the measurement condition needs to be changed. Therefore, if the process of S204 in FIG. 6 is No for a predetermined number of times, the measurement condition can be forcibly changed. In this case, calculation of feature points in one cycle is interrupted, but deterioration in detection accuracy of a biological signal due to inappropriate measurement conditions can be suppressed.

<Second embodiment>
Next, the second embodiment will be described focusing on the differences from the first embodiment. In the first embodiment, the changed measurement condition is determined in S205 of FIG. 6, and changed to the determined measurement condition in S206. In the present embodiment, there is a limit on the amount of change in measurement conditions. FIG. 8 is a flowchart of the measurement condition changing process according to the present embodiment. The processing from S300 to S303 is the same as the processing from S200 to S203 in FIG.

  If it is determined that the measurement condition needs to be changed in S303, the condition changing unit 14 determines whether the change of the measurement condition is completed by the end of the current cycle in S304. Also in the present embodiment, as in the first embodiment, the condition changing unit 14 obtains the predicted time CX, and sets the time after the change time D from the current time as the completion time CP. The condition changing unit 14 determines that the measurement condition cannot be changed if the completion time CP is later than the predicted time CX, and otherwise determines that the measurement condition can be changed. If it is determined that the measurement condition can be changed in S304, the condition changing unit 14 determines a new measurement condition in S305. The method for determining new measurement conditions is the same as in the first embodiment. Subsequently, the condition changing unit 14 determines the change amount of the measurement condition in S306. For example, when changing the light emission intensity of the white light source 21, the condition changing unit 14 obtains the upper limit of the change amount as a ratio with respect to the intensity before the change. For example, the ratio can be 0.5%. Then, if the change amount for changing to the measurement condition determined in S305 exceeds the upper limit, the condition changing unit 14 sets the upper limit as the change amount. On the other hand, if the change amount for changing to the measurement condition determined in S305 does not exceed the upper limit, the change amount determined in S306 becomes the change amount for changing to the measurement condition determined in S305. It should be noted that the upper limit of the change amount can be defined not by the ratio but by its absolute value. Note that the upper limit value of the change amount or a parameter for determining the upper limit value is stored in the ROM 51 in advance.

  In S307, the condition changing unit 14 changes the measurement condition by the change amount determined in S306. In step S308, the condition changing unit 14 determines whether the changed measurement condition is the measurement condition determined in step S305. If the measurement condition after the change is the measurement condition determined in S305, the condition changing unit 14 determines in S309 whether the measurement of the biological information is completed. On the other hand, if the changed measurement condition does not reach the measurement condition determined in S305, the condition changing unit 14 repeats the process from S304. When the process is repeated from S304, the condition changing unit 14 determines that the current time, which is a reference for calculating the completion time CP in the determination in the next S304, is a predetermined time W after the timing at which the measurement condition is changed in S307. The timing of The predetermined time W can be the same as the change time D. That is, when changing the measurement condition a plurality of times within one cycle of the biological signal, the condition changing unit 14 secures the predetermined time W as the timing interval for changing the measurement condition. This is to change the next measurement condition after the biological signal is stabilized after the previous change of the measurement condition.

  FIG. 9A shows a state in which the measurement condition is changed a plurality of times after the calculation of the feature point at the timing Tb and before the timing Tc. The interval between the change timings of the measurement conditions adjacent in time is the predetermined time W as described above. FIG. 9B shows an example of the biological signal when the measurement conditions are changed in the period from the timing Tb to Tc in each of the two cycles of the biological signal. FIG. 9C shows an example of an acceleration signal when the measurement condition is changed a plurality of times between timing Tb and Tc in each of the two periods of the biological signal.

  As described above, in this embodiment, by providing an upper limit for the change amount of the measurement condition, it is possible to suppress changes in the biological signal and the acceleration signal with respect to the change in the measurement condition. For example, when a volume pulse wave signal is detected as a biological signal and measurement is performed while displaying an acceleration signal on the external device 30, an unnecessary signal change at a location that is not a feature point of the acceleration signal can be reduced. Further, when the pulse rate is calculated from the interval between the local maximum values of the acceleration signal, it is possible to reduce the possibility that the pulse rate is erroneously detected due to a change in the acceleration signal resulting from the change of the measurement condition.

  In each of the above embodiments, the measurement condition to be changed during measurement is only the emission intensity of the white light source 21. However, in addition to or instead of the light emission intensity of the white light source 21, the charge accumulation time of the line sensor 24 can be changed. Furthermore, when the light receiving sensitivity (gain) of the line sensor 24 can be switched, the light receiving sensitivity (gain) of the line sensor 24 can be changed as a measurement condition.

[Other Embodiments]
In the above embodiment, the line sensor 24 of the measuring apparatus 1 receives reflected light from the measurement object 90, but may be configured to receive transmitted light. Moreover, the external appearance and mechanical structure of the measuring apparatus 1 of this invention are not limited to what is shown in FIG.

  The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  21: white light source, 22: diffraction grating, 24: line sensor, 13: biological signal generation unit, 15: period determination unit, 16: feature amount calculation unit, 14: condition change unit,

Claims (17)

A light source that emits light toward the measurement position, a spectroscopic unit that splits reflected light from the living body at the measurement position or transmitted light that has passed through the living body at the measurement position, and a plurality of pixels Each of the plurality of pixels includes a light receiving means for receiving light including a predetermined wavelength dispersed by the light separating means, and a spectral sensor including:
Generating means for generating a biological signal from a light reception result of a predetermined pixel of the light receiving means;
First determination means for determining a cycle of the biological signal;
Detecting means for detecting a feature amount of the biological signal;
Setting means for setting the measurement condition of the living body in the spectroscopic sensor;
Second determination means for determining whether the measurement condition needs to be changed based on the biological signal;
When the second determination unit determines that the measurement condition needs to be changed in the first cycle of the biological signal, the detection unit detects the feature amount in the first cycle, and then the first cycle ends. Third determination means for determining whether the measurement condition can be changed within a period until time;
A measuring apparatus comprising:   The measurement apparatus according to claim 1, wherein the third determination unit estimates an end time of the first period based on one or more second periods before the first period.   The measurement apparatus according to claim 2, wherein the third determination unit estimates an end time of the first period based further on a variation amount of the period of the biological signal.   The third determination unit compares the time required for changing the measurement condition with a period from when the detection unit detects the feature amount to the end time of the first cycle in the first cycle. 4. The measurement apparatus according to claim 1, wherein it is determined whether the measurement condition can be changed. The first determination means determines a cycle of the biological signal based on an extreme value of the biological signal,
The third determination means obtains a sum of a time required for changing the measurement condition and a predetermined time required for the first determination means to detect an extreme value of the biological signal, and the sum and the first It is determined whether the measurement condition can be changed by comparing a period from the detection of the feature amount by the detection period to a time until the end time of the first period. Item 4. The measuring device according to any one of Items 1 to 3.   The said 2nd determination means determines whether the change of the said measurement conditions is required in the said period based on the peak value of the period of the said biomedical signal, The any one of Claim 1 to 5 characterized by the above-mentioned. Measuring device.   The measurement apparatus according to claim 6, wherein the second determination unit determines that the measurement condition needs to be changed in the period when the peak value of the period of the biological signal is not within a predetermined range.   When the second determination unit determines that the measurement condition needs to be changed based on the peak value of the first period, the setting unit determines the measurement condition after the change based on the peak value. The measuring apparatus according to claim 7.   9. The measurement according to claim 8, wherein when the third determination unit determines that the measurement condition can be changed in the first period, the setting unit changes the measurement condition after the change. apparatus. The setting means has a parameter for obtaining an upper limit value of the change amount of the measurement condition,
When the third determination unit determines that the measurement condition can be changed in the first period, the setting unit determines whether the change amount for changing to the measurement condition after the change exceeds the upper limit value. The measurement apparatus according to claim 8, wherein when the change amount for changing to the changed measurement condition exceeds the upper limit value, the measurement condition is changed by the upper limit value. .   The third determination unit determines whether or not the measurement condition can be further changed in the first period when the setting unit changes the measurement condition by the upper limit value. 10. The measuring device according to 10.   The measurement apparatus according to claim 1, wherein the measurement condition includes at least one of light emission intensity of the light source, light reception time of the light receiving unit, and light reception sensitivity of the light receiving unit. .   The measurement apparatus according to claim 1, wherein the biological signal is a pulse wave signal.   14. The measuring apparatus according to claim 13, wherein the detection unit uses information of a change point of a signal obtained by differentiating the pulse wave signal at least once as the feature amount.   The detection means obtains a differential signal obtained by differentiating the pulse wave signal twice or four times, and uses a predetermined number of extreme values of the differential signal as the feature amount from the timing of the extreme value of the pulse wave signal. The measuring apparatus according to claim 13 or 14, characterized in that: A light source that emits light toward the measurement position, a spectroscopic unit that splits reflected light from the living body at the measurement position or transmitted light that has passed through the living body at the measurement position, and a plurality of pixels Each of the plurality of pixels includes a light receiving means for receiving light including a predetermined wavelength dispersed by the light separating means, and a spectral sensor including:
Generating means for generating a biological signal from a light reception result of a predetermined pixel of the light receiving means;
Detecting means for detecting a feature amount of the biological signal;
Setting means for setting the measurement condition of the living body in the spectroscopic sensor;
With
The measuring device is characterized in that the measuring condition of the living body is set within a period from when the detecting means detects the feature amount to the end time of the cycle in the cycle of the biological signal. A light source that emits light toward the measurement position, a spectroscopic unit that splits reflected light from the living body at the measurement position or transmitted light that has passed through the living body at the measurement position, and a plurality of pixels Each of the plurality of pixels includes a light receiving means for receiving light including a predetermined wavelength dispersed by the light separating means, and a spectral sensor including:
One or more processors;
When executed on the one or more processors of the measuring device having
In the measuring device,
Setting the measurement conditions of the living body in the spectroscopic sensor;
Generating a biological signal from the light reception result of the predetermined pixel of the light receiving means;
Determining the period of the biological signal;
Detecting a feature quantity of the biological signal;
It is determined whether or not the measurement condition needs to be changed, and if it is determined that the measurement condition needs to be changed in the first period of the biological signal, the feature amount is detected in the first period and then the first amount is detected. Determining whether the measurement condition can be changed within a period up to an end time of one cycle;
A program characterized by having executed.

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