JP2019171012A - Biological information measuring device, biological information measuring method, and biological information measuring system - Google Patents

Abstract

To select a wavelength suitable for measuring biological information.SOLUTION: A biological information measuring device includes a light source for irradiating a light onto a measurement object, and a light reception unit for receiving light volume of a reflection light of the light from the measurement object, and selects a wavelength used for measuring biological information from a plurality of wavelengths on the basis of the light volume received by the light reception unit for each of the plurality of wavelengths of the reflection light.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a biological information measuring device, a biological information measuring method, and a biological information measuring system.

  In recent years, a part of the human body is irradiated with light having a specific wavelength, and the amount of light reflected or transmitted from the blood moving through the blood vessels in the living body is detected using a light receiving sensor, thereby accompanying the movement of blood. A pulse wave measuring device that detects a blood pulse wave (hereinafter referred to as a pulse wave) is commercially available. The pulse wave is used to measure the pulse rate. Also, using the acceleration pulse wave obtained by second-order differentiation of the pulse wave, obtain the degree of vascular hardening due to aging of the inner wall of the blood vessel or accumulation, and present this as the degree of blood vessel aging or blood vessel age Has been proposed.

  In general, this type of pulse wave measuring device includes a light emitting unit (for example, an LED) that irradiates light on a fingertip of a subject and a light receiving unit (for example, a photodiode) that receives light transmitted or reflected in a living body. Have The pulse wave measuring device detects a pulse wave based on fluctuations in the amount of light received by the light receiving unit. For the pulse wave measurement, the light absorption characteristic of hemoglobin in blood is generally used. Therefore, the light emitting unit and the light receiving unit of the pulse wave measuring device have characteristics suitable for measurement in a wavelength region where the light absorption characteristic of hemoglobin is high. Patent Document 1 describes a pulse wave sensor that uses a white LED as a light source and detects the amount of reflected light using a G (green) sensor and an R (red) sensor. The pulse wave sensor of Patent Document 1 detects green light of light reflected in a living body with a G sensor, a red light and an R sensor, and detects information related to a pulse wave based on a level difference between them. .

Japanese Patent Laid-Open No. 2006-083030

  In general, the characteristics of the light emitting unit and the light receiving unit used in the pulse wave measuring apparatus are adjusted so that the light quantity in the wavelength region where the light absorption characteristic of hemoglobin is high can be detected. Also in Patent Document 1, the fluctuation (pulse wave) of the molar absorption coefficient of oxyhemoglobin is detected by detecting the amount of green light (wavelength = 550 nm) with a green sensor. As described above, in the pulse wave measuring device, the characteristics of the light emitting unit and the light receiving unit are determined so that the light amount of the wavelength set in advance as the wavelength at which the light amount can be detected with high sensitivity can be detected. However, when a plurality of variation elements such as the characteristics of the light emitting / receiving elements of the pulse wave measuring device and the light absorption characteristics of the hemoglobin itself are stacked together, the optimum wavelength for detection (the wavelength at which the pulse wave fluctuation increases) changes. . As a result, there may be a deviation between the wavelength that can be detected with high sensitivity by the pulse wave measurement device and the wavelength that is optimal for actual light quantity detection, and the fluctuation amount of the pulse wave detected by the pulse wave measurement device may be small. If the detected fluctuation amount of the pulse wave is small, it is likely to be affected by noise, so that there is a problem that measurement accuracy deteriorates.

  The present invention has been made in view of the above problems, and an object thereof is to enable selection of a wavelength suitable for measurement of biological information.

The biological information measuring device according to one aspect of the present invention has the following configuration. That is,
A light source that irradiates the object to be measured;
A light receiving unit that receives the amount of reflected light of the light from the measurement target;
Selection means for selecting a wavelength to be used for measurement of biological information from the plurality of wavelengths based on the amount of light received by the light receiving unit for each of the plurality of wavelengths of the reflected light.

  According to the present invention, since a wavelength suitable for measurement of biological information is selected, stable measurement that is not affected by conditions such as a measuring instrument and a subject can be performed.

The figure which shows the external appearance of the pulse-wave measuring apparatus which concerns on 1st Embodiment. The figure explaining the structure of the spectrometer which concerns on 1st Embodiment. The block diagram which shows the example of a control structure in the pulse-wave measuring apparatus of 1st Embodiment. The figure which shows the waveform of a pulse wave and an acceleration pulse wave. The figure explaining the example of the wavelength selection which concerns on 1st Embodiment. The flowchart explaining the wavelength selection process which concerns on 1st Embodiment. The figure which shows the light reception amount change at the time of light quantity adjustment which concerns on 1st Embodiment. The block diagram which shows the functional structure by the pulse-wave measuring apparatus by 1st Embodiment, and PC. The figure explaining the example of the wavelength selection which concerns on 2nd Embodiment. The figure explaining the control in the pulse wave measuring device of a 3rd embodiment. The flowchart which shows the selection process of the light emission part which concerns on 3rd Embodiment. The block diagram which shows the functional structure by the pulse-wave measuring apparatus by 3rd Embodiment, and PC. The flowchart explaining the flow of the measurement which concerns on 4th Embodiment.

<First Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view of a pulse wave measuring device 100 as a biological information measuring device according to the first embodiment. The pulse wave measuring apparatus 100 includes a housing 10 that houses a spectrometer. The upper surface of the housing 10 is a surface on which a measurement target is placed. On the upper surface of the housing 10, an opening 15 that allows light to travel between the measurement object placed on the upper surface and the spectrometer 200 (detailed in FIG. 2) inside the housing 10, and the opening 15 A transparent cover 4 made of a transparent material is provided. A shutter member 2 and a guide member 3 for guiding a measurement target are provided on the opening 15 and the upper portion of the transparent cover 4. 1A shows a state in which the shutter member 2 covers the opening 15, and FIG. 1B shows a state in which the shutter member 2 is retracted, the opening 15 is opened, and the finger 6 to be measured is opened. FIG. 1C is a diagram in which the finger is not shown in the state of FIG.

  In the present embodiment, the shutter member 2 and the guide member 3 are connected or integrally configured. The guide member 3 has a guide shape portion 31 and a finger rest shape portion 32. The guide member 3 and the shutter member 2 are slidable in the X direction shown in FIG. 1 by the guide-shaped portion 31 and the guide rail portion 16 provided in the housing 10. Both end portions of the guide rail portion 16 function as a stopper portion 18a and a stopper portion 18b, and define two positions, a position where the guide-shaped portion 31 abuts against the stopper portion 18a and a position abuts against the stopper portion 18b. When the guide member 3 is moved by the finger 6, the shutter member 2 is moved to the first position (FIG. 1A) that covers the opening 15 at the position facing the opening 15 of the housing 10 and the position facing the opening 15. The pulse wave of the finger 6 is detected by the spectrometer 200 provided inside the main body in the state shown in FIG. The

  2A to 2C are diagrams illustrating the structure of the spectrometer 200. FIG. FIG. 2A is an external view of the spectrometer 200 housed and arranged in the housing 10 of the pulse wave measuring apparatus 100, and FIG. 2B is a spectrum obtained by removing the electric board 201 and the cover member 202a of the spectrometer. It is a figure which shows the internal structure of a total of 200. FIG. In the spectrometer 200, an outer shell is formed by the cover member 202a and the case member 202b. The electric board 201 includes a circuit for amplifying and A / D converting a signal from the line sensor 206 to obtain an output signal (digital signal) for each wavelength. Further, the white LED 203 and the line sensor 206 (a plurality of light receiving elements) are mounted on the electric board 201 (that is, on the same board).

  The optical system of the spectrometer 200 includes a white LED 203, a light guide 204, a diffraction grating 205, and a line sensor 206 as a light source that generates light for irradiating a measurement target. The light guide 204 is a light guide member in which a lighting unit that guides the light flux from the white LED 203 toward the measurement target and a light collection unit that collects and guides reflected light from the measurement target are integrated. The light from the white LED 203 is guided to the opening 15 by the illuminating unit of the light guide 204 and is irradiated to the measurement target (the finger 6 in this example) through the opening 15. The reflected light from the measurement target is condensed and guided by the light guide unit of the light guide 204 and guided to the diffraction grating 205 which is a spectroscopic unit that performs spectroscopy with a predetermined resolution in a predetermined wavelength range. The reflected light is split into a plurality of wavelengths by the diffraction grating 205 as a spectroscopic unit, and the line sensor 206 as a light receiving unit receives the split light. In the line sensor 206, light receiving elements that receive light decomposed into a plurality of wavelengths are arranged in series. The spectrometer 200 includes a white LED 203, a light guide 204, a diffraction grating 205, and a line sensor 206, and realizes miniaturization.

  FIG. 2C shows the order of travel of light rays emitted from the white LED 203 (in the order of arrows R1 to R5) in the spectrometer 200. The light beam R1 emitted from the white LED 203 installed on the electric substrate 201 of the spectrometer 200 is reflected by the curved surface portion of the resin-molded light guide 204, and emitted to the upper surface as irradiation light R2. The irradiation light R <b> 2 passes through the opening 15 and the transparent cover 4 and irradiates the abdomen of the living body measurement target (in this embodiment, the finger 6) placed on the transparent cover 4. The reflected light R3 from the irradiated portion is incident on the incident portion 204a of the resin-molded light guide 204.

  The reflected light incident on the incident portion 204a is condensed and guided by the light guide 204, and is irradiated onto the diffraction grating 205 as a light beam R4. The diffraction grating 205 is a concave reflection type diffraction grating (concave diffraction grating) made of resin and having a diffraction grating formed on the concave surface. The diffraction grating 205 is formed, for example, by vapor-depositing a reflective film such as aluminum and an enhanced reflective film such as SiO 2 on the surface of the diffraction grating. The light beam R5 split by the diffraction grating 205 is applied to the line sensor 206 installed on the electric substrate 201.

  FIG. 3 is a block diagram showing a control configuration of the pulse wave measuring apparatus 100. In FIG. 3, a pulse wave measuring device 100 as a detecting device including a light source that generates light for irradiating the measuring object and a light receiving unit that detects the amount of reflected light from the measuring object, and the pulse wave measuring device 100 connected thereto. A biological information measurement system having an information processing apparatus is shown. The electric board 201 is equipped with a white LED 203, a line sensor 206, and a spectrometer control unit 207. The spectrometer control unit 207 performs drive control of the white LED 203 and arithmetic processing of the signal detected by the line sensor 206. The spectrometer control unit 207 is connected to a main body control unit 208 that controls the pulse wave measuring device 100, and transmits a detection result by the spectrometer 200 to the main body control unit 208. The main body control unit 208 can communicate with an information processing apparatus that is an external apparatus using a known communication technique. In the present embodiment, a personal computer (hereinafter, PC 209) is used as the information processing apparatus. The main body control unit 208 continuously transmits the measurement results obtained by the spectrometer 200 to the PC 209. The PC 209 is installed with an application for pulse wave measurement, which is calculated from the pulse wave (see FIG. 4 (a)) and the acceleration pulse wave (see FIG. 4 (b)) obtained by differentiating the pulse wave twice. Health care information such as blood vessel age is displayed on the screen of the PC 209. Note that the relationship between the acceleration pulse wave waveform and the blood vessel age is known information, and thus the description thereof is omitted.

  Next, the measurement content of the spectrometer 200 when the finger 6 is actually placed at the measurement position on the upper surface of the pulse wave measurement device 100 will be described. In the present embodiment, the diffraction grating 205 is set to have a shortest wavelength of 400 [nm] and a wavelength resolution of 10 [nm], and the line sensor 206 has 31 light receiving elements. Therefore, the spectrometer 200 of the present embodiment can measure the amount of received light every 10 [nm] in the wavelength region of 400 to 700 [nm].

  FIG. 5A shows the received light amount of each wavelength by the line sensor 206 when the white LED 203 emits light with a predetermined light amount. The vertical axis in FIG. 5A is a value obtained by A / D converting (10-bit resolution) the received light amount waveform converted into an electric signal (analog) by the line sensor 206 by the spectrometer control unit 207. When the data in FIG. 5A is continuously monitored for a predetermined time, the amount of received light varies with the pulsation of the blood vessel (change in the amount of movement of hemoglobin). The fluctuation range of the received light amount at each wavelength within a predetermined time (for example, 5 seconds) is as shown in FIG. Here, the fluctuation range is a difference between the maximum value and the minimum value of the amount of received light measured within a predetermined time. In FIG. 5B, the light amount fluctuation is largest at a wavelength near 580 [nm], and 580 [nm] can be said to be a wavelength suitable for pulse wave measurement from the viewpoint of the S / N ratio. On the other hand, when the pulse wave measuring device or the person to be measured (finger) is different, the light amount fluctuation for each wavelength is shown in FIG. In FIG. 5C, the wavelength at which the light amount fluctuation is maximum is 560 [nm], and the wavelength suitable for pulse wave measurement is different from that in FIG. 5B (580 [nm]). That is, the wavelength suitable for pulse wave measurement with a large fluctuation amount varies depending on the measurement object and the measurement conditions at that time. Therefore, when pulse waves are measured at a fixed wavelength, fluctuations in pulse waves are small (susceptible to noise), and stable measurement may be difficult.

  FIG. 6A is a flowchart for explaining wavelength selection processing in the first embodiment. The spectrometer control unit 207 executes a wavelength selection process described below before starting light amount detection for pulse wave measurement, selects an appropriate wavelength for pulse wave measurement, and the selected wavelength is sufficient. In order to obtain a sufficient amount of received light, the amount of light of the white LED 203 is adjusted.

  First, the spectrometer control unit 207 turns on the white LED 203 with a predetermined light amount (S601), and measures the amount of light received at each wavelength (for example, a wavelength in increments of 50 nm) of all wavelengths (wavelength range of 400 to 700 [nm]). (S602). Thereby, the received light amount data of FIG. 5A described above is obtained. When the spectrometer control unit 207 repeatedly performs the measurement of S602 over a predetermined period (or a predetermined number of times), the spectrometer control unit 207 ends the measurement of the received light amount of all wavelengths (YES in S603). The spectrometer control unit 207 acquires the light amount fluctuation at each wavelength from the plurality of measurement results of the received light amount at S602, and generates the measurement data of the light amount fluctuation at each wavelength as described in FIGS. (S604). The spectrometer control unit 207 determines, from the generated measurement data, the wavelength λmax that maximizes the variation in the amount of received light as the pulse wave measurement wavelength (S605). Then, the spectrometer control unit 207 performs light amount adjustment of the white LED at the determined wavelength (S606).

  FIG. 7 is a diagram illustrating light amount adjustment according to the first embodiment. The solid line in FIG. 7 indicates the light reception amount when the light amount of the white LED 203 is increased by about 1.5 times as a result of the light amount adjustment with respect to the light reception amount shown in FIG. 5A (dotted line in FIG. 7). It is. As a result, for example, the amount of light received at a wavelength of 580 [nm] can be increased to near the maximum value (1023 [dec]) of 10-bit resolution. As a result, the S / N ratio is further improved with respect to the fluctuation range of the amount of received light during pulse wave measurement. The light amount adjustment is performed based on the light amount value output by the line sensor 206 for the wavelength determined in S605. For example, among the received light amount data acquired in S602, the maximum value of the received light amount of the wavelength determined in S605 is set so as not to exceed the maximum resolution value. For example, it is possible to select one of 1.25 times, 1.5 times, and 1.75 times as the light amount adjustment, so that the maximum value of the received light amount of the determined wavelength does not exceed the maximum value of the resolution. The maximum magnification is selected. The above-mentioned 1.5 times is the adjustment amount selected in this way, for example. Or you may make it determine the adjustment amount of a light source based on ratio of the maximum value of the light reception amount of the determined wavelength, and the maximum value of resolution.

  Further, in S605 of FIG. 6A, only the wavelength λmax that maximizes the light amount variation is selected as the pulse wave measurement wavelength, but the present invention is not limited to this. As shown in S605a of FIG. 6B, a wavelength included in a wavelength region having a predetermined width (for example, ± 10 [nm]) including λmax may be selected. In this case, since a plurality of light amounts corresponding to a plurality of wavelengths included in the wavelength region are obtained, the obtained light amount values are used after statistical processing. For example, by adopting a value obtained by averaging the amount of received light, the S / N ratio and the robustness against sudden noise can be improved.

  As described above, when the selection of the wavelength used for the measurement and the light amount adjustment of the white LED 203 are completed, the light amount measurement for the pulse wave measurement is started. That is, the spectrometer control unit 207 drives the white LED 203 so that the light amount adjusted in S606 is obtained, sequentially acquires the light amount of the wavelength determined in S605 from the line sensor 206, and sends it to the main body control unit 208. The main body control unit 208 transmits the light amount data received from the spectrometer control unit 207 to the PC 209. Thus, the PC 209 can obtain a pulse wave as shown in FIG. 4A from the pulse wave measurement device 100. The PC 209 acquires and displays the pulse rate based on this pulse wave. Further, for example, the PC 209 estimates the blood vessel age based on a waveform (FIG. 4B) obtained by differentiating the pulse wave twice, and displays the estimation result.

  FIG. 8 is a block diagram illustrating a functional configuration example related to pulse wave measurement according to the first embodiment. The all-wavelength light quantity acquisition unit 701 acquires the light quantity of each wavelength over all wavelengths from the line sensor 206 over a predetermined period (or a predetermined number of times) (S601 to S603). The light amount variation acquisition unit 702 acquires the light amount variation at each wavelength from the light amount of a predetermined period (or a predetermined number of times) acquired by the all wavelength light amount acquisition unit (S604). The wavelength selection unit 703 selects and determines a wavelength to be used for biological information measurement such as pulse wave measurement from the above-described all wavelengths based on the light amount variation acquired by the light amount variation acquisition unit 702 (S605). The light emission amount adjustment unit 704 adjusts the light emission amount of the white LED 203 so that the light amount of the wavelength selected by the wavelength selection unit 703 is increased (S606).

  When the selection of the wavelength suitable for measurement and the adjustment of the light emission amount of the light source are completed as described above, the light amount measurement for pulse wave measurement is started. That is, the light amount acquisition unit 705 turns on the white LED 203 with the light emission amount adjusted by the light emission amount adjustment unit 704, and sequentially acquires the light amount of the wavelength selected by the wavelength selection unit 703 from the line sensor 206. The pulse wave detection unit 706 acquires a light amount arranged in time series from the light amount acquisition unit 705, generates a pulse wave, and measures the pulse rate based on the pulse wave. Further, the pulse wave detection unit 706 estimates the blood vessel age based on a waveform obtained by differentiating the pulse wave twice. The measurement result and the estimation result are displayed on a display provided in the PC 209.

  In the present embodiment, the full-wavelength light amount acquisition unit 701 to the light amount acquisition unit 705 are realized in the pulse wave measurement device 100, that is, by the spectrometer control unit 207 and the main body control unit 208. The light amount acquisition unit 705 transmits the acquired light amount to the PC 209, and the PC 209 on which the pulse wave measurement application operates functions as the pulse wave detection unit 706. However, the division of roles between the pulse wave measurement device 100 and the PC 209 is not limited to this, and for example, the light quantity fluctuation acquisition unit 702 to the wavelength selection unit 703 may be realized on the PC 209 side. In this case, the all-wavelength light amount acquisition unit 701 notifies the PC 209 of the acquired light amount, and the wavelength selection unit 703 included in the PC 209 notifies the light emission amount adjustment unit 704 of the pulse wave measurement device 100 of the wavelength selection result.

  In the first embodiment, the configuration including the PC 209 is described, but the configuration is not limited thereto. For example, a series of operations from measurement to analysis / result display, in which a display unit is provided in the pulse wave measuring device 100 and the main body control unit 208 counts the pulse wave number and estimates the blood vessel age and displays it on the display unit. May be implemented by the pulse wave measuring apparatus 100. In this case, the functions of the full-wavelength light quantity acquisition unit 701 to the pulse wave detection unit 706 are realized by the spectrometer control unit 207 and the main body control unit 208.

  As described above, according to the first embodiment, it is possible to select an optimum wavelength for pulse wave measurement from all wavelengths, and thus stable pulse wave measurement is possible.

<Second Embodiment>
In the first embodiment, an appropriate wavelength for pulse wave measurement is selected by specifying a wavelength that maximizes the amount of fluctuation in light quantity. In the second embodiment, a wavelength region in which the amount of light amount fluctuation exceeds a predetermined value is selected as a wavelength region used for pulse wave measurement. The configuration of the pulse wave measurement device according to the second embodiment is the same as that of the first embodiment (FIGS. 1 to 3).

  Also in the second embodiment, as in the first embodiment, the spectrometer control unit 207 measures the received light amount of each wavelength within a predetermined time (S601 to S603), and obtains the light amount fluctuation of each wavelength (S604). FIG. 9A shows an example of the light amount fluctuation of each wavelength according to the second embodiment. The spectrometer control unit 207 of the present embodiment determines a wavelength region in which the light amount fluctuation exceeds a predetermined threshold as a wavelength region used for pulse wave measurement. In the example of FIG. 9A, a wavelength region (580 to 590 [nm]) in which the light amount fluctuation exceeds a predetermined threshold (90 [dec]) is determined as a pulse wave measurement wavelength region.

  FIG. 9B is a diagram showing a fluctuation range of the received light amount of each wavelength within a predetermined time while the white LED 203 is turned off. The fluctuation amount shown in FIG. 9B is caused by the influence of various variation factors such as fluctuations in the power supply voltage (not shown) of the pulse wave measuring apparatus 100 and AD conversion errors of the spectrometer control unit 207. In this example, it is understood that it is about 10 [dec]. In performing the pulse wave measurement, the above-described variation amount threshold value needs to be larger than the variation amount variation amount (about 10 [dec]) of FIG. 9B. In the present embodiment, 90 [dec] is set as the threshold value, and as a result, the variation amount of about the variation element is about 9 times (threshold value (90 [dec]) / the variation amount of the variation element (about 10 [dec]). ) Margin is obtained.

  Note that, when there is no wavelength whose light amount fluctuation exceeds the threshold = 90 [dec], the spectrometer control unit 207 may appropriately reduce the threshold and acquire a wavelength region exceeding the threshold. Further, before the spectrometer control unit 207 turns on the white LED 203, that is, while the white LED 203 is turned off, the light amount fluctuation (FIG. 9B) is measured, and the threshold value is set based on the measurement result. Good. For example, an average value of the light amount fluctuations of the respective wavelengths obtained during turn-off or a value obtained by multiplying the maximum value of the obtained light quantity fluctuations by a predetermined value (for example, 9 times) may be used as the threshold value.

  As described above, according to the second embodiment, the wavelength to be selected for pulse wave measurement can be determined from the value of the fluctuation amount, so that stable pulse wave measurement is possible.

<Third Embodiment>
In the first embodiment and the second embodiment, in the pulse wave measurement device 100 using a spectrometer, an appropriate wavelength to be used for pulse wave measurement is determined based on light amount fluctuations of a plurality of wavelengths. In the third embodiment, an LED having a plurality of LEDs having different wavelengths and having a wavelength used for pulse wave measurement is selected.

  FIG. 10A is a block diagram of the pulse wave measuring device 100 according to the third embodiment. In the third embodiment, instead of the spectrometer 200 of the first and second embodiments, an LED 211 and an LED 212 as two light sources having different wavelengths, a photodiode 213 as a light receiving element, and a main body control unit 208 are mounted. 201 is provided. As shown in FIG. 10B, the electric board 201 is horizontal to the measurement target (finger), that is, the surface of the electric board 201 on which the LED 211, LED 212, and photodiode 213 are mounted is the housing 10. Arranged to be parallel to the top surface. The relationship between the main body control unit 208 and the PC 209 is the same as that in the first embodiment.

  Next, a wavelength selection method in the third embodiment will be described using the flowchart of FIG. Before starting the pulse wave measurement, the main body control unit 208 turns on the LED 211 with a predetermined light amount (S1001). The main body control unit 208 measures the amount of light received by the photodiode 213 at that time over a predetermined period (S1002), and obtains the light amount fluctuation in the light emission of the LED 211. Thereafter, the main body control unit 208 turns off the LED 211 (S1003). Subsequently, the main body control unit 208 turns on the LED 212 with a predetermined light amount (S1004). The main body control unit 208 measures the amount of light received by the photodiode 213 at that time over a predetermined period (S1005), and obtains a light amount variation in light emission of the LED 212. Thereafter, the main body control unit 208 turns off the LED 212 (S1006). The light amount variation is the difference between the maximum value and the minimum value of the received light amount measured a plurality of times in a predetermined period, as in the first embodiment.

  The main body control unit 208 determines which of the light amount fluctuations is greater when the LED 211 is lit or when the LED 212 is lit (S1007). If the variation in the amount of light when the LED 211 is lit is larger (YES in S1007), the LED 211 is selected for pulse wave measurement (S1008). On the other hand, when the light amount fluctuation at the time of lighting of the LED 211 is larger (NO in S1007), the LED 212 is selected for pulse wave measurement (S1009). Thereafter, the main body control unit 208 performs light amount adjustment on the selected LED (S1010). The operation for adjusting the light amount is the same as that in the first embodiment.

  In the third embodiment, for example, when the LED 211 emits light at 560 [nm] and the LED 212 emits light at 580 [nm], the wavelength suitable for the light amount fluctuation as shown in FIGS. 5B and 5C. LEDs can be selected. Furthermore, by increasing the number of LEDs having different wavelengths (using three or more LEDs having different wavelengths), it is possible to select the LEDs having wavelengths suitable for the environment more finely.

  FIG. 12 is a block diagram illustrating a functional configuration example of the pulse wave measurement device 100 and the PC 209 according to the third embodiment. The light quantity fluctuation measuring unit 1201 individually turns on a plurality of light sources having different wavelengths, and acquires fluctuations in the reflected light quantity (light quantity fluctuation) using the photodiode 213. That is, the light quantity variation measuring unit 1201 executes S1001 to S1006. The light source selection unit 1202 selects a light source used for pulse wave measurement (that is, the wavelength of light used for pulse wave measurement) based on the light amount fluctuation acquired by the light quantity fluctuation measuring unit 1201 (S1007 to S1009). The light emission amount adjustment unit 1203 adjusts the light amount of the LED selected by the light source selection unit 1202 (S1010).

  The light amount acquisition unit 1204 sequentially acquires the light amount detected by the photodiode 213 using the light source (LED) selected by the light source selection unit 1202 and the light amount adjusted by the light emission amount adjustment unit 1203, and the pulse wave detection unit To 1205. The pulse wave detection unit 1205 acquires the light amount arranged in time series from the light amount acquisition unit 1204, generates a pulse wave (FIG. 4A), and measures the pulse rate based on the pulse wave. Further, the pulse wave detection unit 706 estimates the blood vessel age based on a waveform obtained by differentiating the pulse wave twice. The measurement result and the estimation result are displayed on a display provided in the PC 209. In the present embodiment, the light amount variation measuring unit 1201 to the light amount acquiring unit 1204 are realized by the main body control unit 208, and the pulse wave detecting unit 1205 is realized by the PC 209. However, the light source selection unit 1202 may be realized by the PC 209.

  In the above embodiment, a plurality of LEDs having different wavelengths are provided, but a plurality of photodiodes (light receiving portions) having sensitivity to different wavelengths may be provided. In this case, the light source can have one white LED. From the measurement result of the light amount fluctuation for each wavelength, a photodiode corresponding to the wavelength having the largest light amount fluctuation is selected and used for pulse wave measurement.

  As described above, according to the third embodiment, stable pulse wave measurement can be performed with a cheaper configuration that does not use a spectrometer.

<Fourth embodiment>
In 1st Embodiment and 2nd Embodiment, the selection method of the wavelength utilized for a measurement was demonstrated in the pulse-wave measuring apparatus 100 using a spectrometer. In both the first and second embodiments, processing for selecting a wavelength used for measurement is executed prior to pulse wave measurement. In the fourth embodiment, wavelength selection is performed in the flow of biological information measurement (for example, pulse wave measurement) using the pulse wave measurement device 100. More specifically, in the fourth embodiment, the light amount fluctuation at a preset wavelength (predetermined wavelength) is measured, and if the light amount fluctuation amount is equal to or greater than a predetermined value, the biological information (pulse wave) is obtained from the light amount fluctuation. get. Therefore, if the amount of light fluctuation at a predetermined wavelength is equal to or greater than a predetermined value, the time required for measuring biological information is shortened compared to the first and second embodiments.

  The configuration of the pulse wave measurement device according to the fourth embodiment is the same as that of the first embodiment (FIGS. 1 to 3). The wavelength selection process in the fourth embodiment will be described below with reference to the flowchart of FIG.

  First, the spectrometer control unit 207 turns on the white LED 203 with a predetermined light amount P1 (S1301), and measures the amount of received light at a predetermined wavelength (predetermined wavelength A) (S1302). When the spectrometer control unit 207 repeatedly executes the measurement of S1302 over a predetermined period (or a predetermined number of times), the spectrometer control unit 207 ends the measurement of the amount of received light at the predetermined wavelength A (S1303). The spectrometer control unit 207 acquires the light amount fluctuation amount at the predetermined wavelength A from the measurement result of the received light amount in S1302 (S1304).

  The spectrometer control unit 207 compares whether or not the calculated light amount fluctuation amount of the wavelength A is equal to or greater than a predetermined value (S1305), and if it is equal to or greater than the predetermined value (YES in S1305), Biological information is acquired based on the variation in the amount of light (S1315). At this time, the amount of received light measured in S1302 may be used as part of data used for acquiring biometric information in S1315. On the other hand, when the light amount fluctuation amount of the wavelength A calculated in S1304 is equal to or smaller than the predetermined value (NO in S1305), the spectrometer control unit 207 executes the wavelength selection process shown in FIG. 6 (S601 to S605). (S1306). Here, the wavelength selected by the wavelength selection processing in S1306 is assumed to be wavelength B. The spectrometer control unit 207 continues to turn on the white LED 203 with the predetermined light amount P1, and measures the received light amount at the selected wavelength B (S1307). When the measurement of S1307 is repeatedly performed over a predetermined period (or a predetermined number of times), the spectrometer control unit 207 ends the measurement of the received light amount at the wavelength B (S1308).

  Subsequently, the spectrometer control unit 207 acquires the light amount fluctuation at the wavelength B from the measurement result of the received light amount in S1307 (S1309). The spectrometer control unit 207 compares whether or not the calculated light amount fluctuation amount of the wavelength B is equal to or greater than a predetermined value (S1310). Biometric information is acquired (S1314). At this time, the amount of received light measured in S1307 may be used as a part of data used for acquiring biological information in S1314. On the other hand, when the light amount fluctuation amount of the wavelength B calculated in S1310 is equal to or smaller than the predetermined value, the spectrometer control unit 207 changes (increases) the light amount of the white LED 203 to P2 (> P1) (S1311), and again, The amount of light received at wavelength B is measured (S1312). When the measurement of S1302 is repeatedly performed over a predetermined period (or a predetermined number of times), the spectrometer control unit 207 ends the measurement of the received light amount at the wavelength B (S1313). Thereafter, the spectrometer control unit 207 acquires biological information based on the change in the light amount of the wavelength B acquired in S1312 (S1314).

  In the above processing, when the amount of light received at the predetermined wavelength A is measured, a single wavelength is measured. However, the present invention is not limited to this. For example, in the configuration using the spectrometer 200, when the amount of light received at the predetermined wavelength A is measured, the amount of light received can be detected for each of a plurality of other wavelengths. Therefore, for example, if there is a margin in the sampling cycle, the received light amount may be measured for a plurality of wavelengths in S1302, and the received light amount measured in S1302 may be used when performing the wavelength selection process in S1306. Further, although the received light amount is measured for the wavelength B in S1307 to S1308, the result of the measurement performed in S1306 (the result of S602 and S603) may be used. Furthermore, when the wavelength B is selected in S1309, the predetermined wavelength A used in S1302 to S1304 and S1315 may be updated with the wavelength B. That is, the selected wavelength may be set as the measurement wavelength for the next measurement.

  As described above, according to the fourth embodiment, it is possible to reduce the measurement time and the power consumption because the wavelength selection process and the LED light amount can be suppressed.

  In the fourth embodiment, the biological information measuring apparatus using a spectrometer has been described as an example, but the present invention is not limited to this. For example, the present invention can be applied to a measuring apparatus including a plurality of light sources having different wavelengths or a plurality of light receiving units having different wavelength sensitivities as described in the third embodiment. For example, in a measurement apparatus having a plurality of light sources, if the amount of light fluctuation measured using a predetermined light source is greater than or equal to a predetermined value, the biological information is measured using the light source, and the amount of light fluctuation is less than the predetermined value. If it is smaller, the biological information is measured again using the selected light source. Here, the selection of the light source is as described in the third embodiment. The selected light source may be set to a predetermined light source at the next measurement. Similarly, in the case of a measuring apparatus having a plurality of light receiving units, if the amount of light fluctuation measured using a predetermined light receiving unit is greater than or equal to a predetermined value, the biological information is measured using the light receiving unit, and the light quantity fluctuation When the amount is smaller than the predetermined value, the biological information is measured again using the selected light receiving unit. Here, the selection of the light receiving unit is as described in the third embodiment. The selected light receiving unit may be set to a predetermined light receiving unit at the next measurement. By selecting the light source or the light receiving unit as described above, the same effect as described above can be obtained.

<Fifth Embodiment>
In the fourth embodiment, first, the amount of received light is measured using a predetermined wavelength (predetermined wavelength A), and when the light amount fluctuation at that time is equal to or smaller than a predetermined value (when it is determined that the predetermined wavelength A is not adopted) (Ii) A wavelength selection process was performed.

  In the fifth embodiment, first, after measuring the amount of received light at each of a plurality of wavelengths (for example, five predetermined wavelengths A to E), at a predetermined wavelength (for example, wavelength A) among them. Wavelength selection processing is performed when the amount of light fluctuation is equal to or less than a predetermined value. Then, when the predetermined wavelength (A) is not adopted, the light reception obtained at the wavelength presenting the largest light reception fluctuation amount among the other wavelengths (B to E) in which the light reception amount has been measured. Biological information is acquired using the quantity variation. Therefore, in the fifth embodiment, since the light reception amounts of a plurality of wavelengths are measured in advance, there is no need to measure the light reception amounts at each of the plurality of wavelengths in the wavelength selection process when the predetermined wavelength A is not adopted. The time required for the wavelength selection process is shortened.

  In the fifth embodiment, the process of S1302 in the flowchart of FIG. 13 is a process of “measuring the amount of received light of a plurality of wavelengths”. Further, in the wavelength selection process of S1306, S601 to 603 in the flowchart of FIG. Among the remaining wavelengths other than the predetermined wavelength A, the wavelength at which the largest received light fluctuation amount is obtained is selected.

  As described above, according to the fifth embodiment, even if a predetermined wavelength A is not adopted and a wavelength selection process is necessary by measuring the amounts of received light of a plurality of wavelengths in advance, the processing is performed. Time can be shortened.

  Similarly to the fifth embodiment, when the wavelength B is selected in S1309, the predetermined wavelength A used in S1302 to S1304 and S1315 may be updated with the wavelength B. That is, the selected wavelength may be set as the measurement wavelength for the next measurement.

(Other examples)
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 It is also possible to implement this process. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100: Pulse wave measuring device, 203, 211, 212: LED, 206: Line sensor, 207: Spectrometer control unit, 208: Main body control unit, 209: Personal computer

Claims (28)

A light source that irradiates the object to be measured;
A light receiving unit that receives the amount of reflected light of the light from the measurement target;
Biological information measurement comprising: selection means for selecting a wavelength to be used for measuring biological information from the plurality of wavelengths based on the amount of light received by the light receiving unit for each of the plurality of wavelengths of the reflected light. apparatus.   The biological information measuring apparatus according to claim 1, further comprising: a transmitting unit that transmits a light amount detected by the light receiving unit with respect to light having a wavelength selected by the selecting unit to an external device.   The biological information measuring apparatus according to claim 1, further comprising a measuring unit that measures biological information based on the amount of reflected light having a wavelength selected by the selecting unit, which is detected by the light receiving unit. A spectrometer that divides the reflected light into light beams of the plurality of wavelengths;
2. The light receiving unit includes a plurality of light receiving elements provided corresponding to the light beams of the plurality of wavelengths, and detects light amounts of a plurality of wavelengths using the plurality of light receiving elements. 4. The biological information measuring device according to any one of items 1 to 3. The selection means includes
Including acquisition means for acquiring a light amount variation that is a variation amount of the light amount detected by the light receiving unit for each of the plurality of wavelengths of the reflected light;
The biological information measuring apparatus according to claim 1, wherein a wavelength used for measuring biological information is selected based on the light amount fluctuation.   The biological information measuring apparatus according to claim 5, wherein the selection unit selects a wavelength having the largest light amount fluctuation.   The biological information measuring apparatus according to claim 5, wherein the selection unit selects a wavelength included in a wavelength region having a predetermined width including a wavelength having the largest light amount fluctuation.   The biological information measuring apparatus according to claim 5, wherein the selection unit selects a wavelength at which the light amount fluctuation exceeds a predetermined threshold value.   The biological information measuring apparatus according to claim 8, wherein the predetermined threshold is a value larger than a light amount fluctuation while the light source is turned off.   9. The biological information measuring apparatus according to claim 8, further comprising setting means for setting the predetermined threshold based on a light amount variation measured while the light source is turned off.   The biological information measuring apparatus according to claim 7, further comprising a unit that statistically processes the light amount of the selected wavelength.   The biological information measuring apparatus according to claim 1, wherein the light source is a white LED.   The biological information is measured again using the wavelength selected by the selection means when the amount of light fluctuation measured using a predetermined wavelength is smaller than a predetermined value. The biological information measuring device according to any one of the above.   When the light amount fluctuation amount at a predetermined wavelength is smaller than a predetermined value among the light amounts at each of the plurality of wavelengths received by the light receiving unit, the biological information is again obtained using the wavelength selected by the selection unit. The biological information measuring device according to claim 1, wherein the biological information measuring device is measured.   The biological information measuring device according to claim 13 or 14, wherein the wavelength selected by the selecting means is set as a wavelength for measurement at the next measurement. The light source has a plurality of light sources having different wavelengths of output light,
The said selection means selects the light source used for measurement of biological information from these several light sources based on the light quantity of the said reflected light obtained by lighting each of these several light sources. Biological information measuring device.   The biological information measuring apparatus according to claim 16, further comprising a measuring unit that measures biological information by turning on a light source selected by the selecting unit.   18. The biological information is measured again using the light source selected by the selection means when the light amount fluctuation amount measured using a predetermined light source is smaller than a predetermined value. Biological information measuring device.   19. The biological information measuring apparatus according to claim 18, wherein the light source selected by the selecting means is set as a light source for the next measurement. The light receiving unit has a plurality of light receiving units having sensitivity to different wavelengths,
2. The living body according to claim 1, wherein the selection unit selects a light receiving unit to be used for measuring biological information from the plurality of light receiving units based on a light amount of the reflected light obtained from the plurality of light receiving units. Information measuring device.   21. The biological information measuring apparatus according to claim 20, further comprising a measuring unit that measures biological information using the light receiving unit selected by the selecting unit.   The biological information is measured again using the light receiving unit selected by the selection means when the light amount fluctuation amount measured using a predetermined light receiving unit is smaller than a predetermined value. The biological information measuring device according to 1.   23. The biological information measuring apparatus according to claim 22, wherein the light receiving unit selected by the selection unit is set as a light receiving unit for the next measurement.   The biological information measuring device according to any one of claims 3, 17, and 21, further comprising display means for displaying biological information measured by the measuring means.   25. The adjusting device according to claim 1, further comprising an adjusting unit that adjusts a light amount of the light source based on a light amount value output by the light receiving unit with respect to the wavelength selected by the selecting unit. Biological information measuring device. Biological information measurement having a detection device including a light source that irradiates light to the measurement target, a light receiving unit that receives the amount of reflected light of the light from the measurement target, and an information processing device connected to the detection device A system,
Selection means for selecting a wavelength to be used for measuring biological information from the plurality of wavelengths based on the amount of light received by the light receiving unit for each of the plurality of wavelengths of the reflected light;
A biological information measuring system comprising: measuring means for measuring biological information based on the amount of reflected light having a wavelength selected by the selecting means. A biological information measuring method,
An acquisition step of irradiating the measurement target with light from the light source and acquiring the amount of light received by the light receiving unit for each of the plurality of wavelengths of the reflected light of the light from the measurement target;
A selection step of selecting a wavelength to be used for measurement of biological information from the plurality of wavelengths based on the amount of light acquired in the acquisition step;
A biological information measurement method, comprising: measuring biological information based on the amount of reflected light having a wavelength selected in the selection step.   The program for making a computer perform each process of the biometric information measuring method described in Claim 27.

Images