JP2009011593A - Non-invasive biological information measuring device - Google Patents

Abstract

A noninvasive living body information measuring apparatus capable of stopping irradiation of light other than during measurement without increasing the size of the apparatus.
A control means for controlling a light source, a light source for irradiating a living body with light of a specific wavelength, a photoacoustic detection means for detecting a photoacoustic wave signal generated in the living body, and a photoacoustic detection. The apparatus includes a feature quantity estimating means 50 for estimating the feature quantity of the biological information from the output of the means 40 and a feature quantity display means 60 for displaying the estimation result of the feature quantity, and the apparatus uses the information extracted from the output of the photoacoustic detection means 40. By determining whether or not it is on the skin and controlling the light source 20, it is possible to stop the irradiation of light other than during measurement without increasing the size of the apparatus.
[Selection] Figure 2

Description

  The present invention relates to a non-invasive living body information measuring apparatus capable of measuring living body information without invading a living body, and more specifically, stops irradiation of light other than during measurement based on a photoacoustic wave signal from the living body. The present invention relates to a non-invasive living body information measuring apparatus capable of operating.

  The number of patients with diabetes, a typical lifestyle-related disease, is increasing worldwide. Diabetic patients require routine glycemic control to reduce complications from diabetes and improve the quality of life of patients. Therefore, patients must measure blood glucose regularly every day under the guidance of a doctor.

  As a typical method for measuring a blood glucose level, there is an invasive blood glucose measuring device that punctures a patient's finger to collect blood and measure the blood glucose level. In an invasive blood glucose measuring device, it is troublesome and painful when blood is collected by puncturing a finger, and there is also a risk of infection, etc. Measuring devices have already been proposed.

  As an example of this non-invasive blood glucose measurement device, a “biological measurement system” using a photoacoustic effect has been proposed (for example, Patent Document 1).

  A “biological measurement system” using a photoacoustic effect irradiates a part of a living body, such as a fingertip, from the biological measurement system with light having a wavelength absorbed by glucose. The light is focused on a relatively small focal area. In general, the collected light is absorbed by glucose and converted into kinetic energy in the tissue in the region adjacent to the focal region.

  The kinetic energy converted in the tissue increases the temperature and pressure of the region of the tissue where the irradiation light is absorbed by glucose (hereinafter referred to as the absorbing tissue region), and generates a sound wave. This sound wave is hereinafter referred to as “photoacoustic wave signal”. The photoacoustic wave signal is emitted from the absorbing tissue region and detected by an acoustic sensor included in the biological measurement system. The acoustic sensor is mounted in contact with the living body surface. The intensity of the photoacoustic wave signal is a function of the amount of glucose in the absorbent tissue region, and the intensity measured by the acoustic sensor is used to examine the blood glucose level.

  At this time, as long as light is irradiated from the skin surface toward the blood vessel in the living body, it does not affect the living body, but for example, when light is incident on the eyeball, in some cases, the light collected by the crystalline lens May affect the retina and may have adverse effects such as decreased vision and blindness.

On the other hand, a method of providing a contact degree sensor that senses the contact degree between the acoustic sensor and the living body separately from the acoustic sensor and controlling the light irradiation according to the sensed contact degree has already been proposed (for example, Patent Document 2).
Special table 2001-526557 gazette JP 2004-147940 A

  By the way, in order to improve the quality of life of a patient, it is desirable to downsize the apparatus to such an extent that it does not become a burden in daily life. However, the technique described in Patent Document 2 senses the degree of contact with a living body. Therefore, there is a problem that the non-invasive biological information measuring device becomes complicated and large in size because an extra sensor and device adjustment mechanism are required.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a noninvasive living body information measuring apparatus capable of stopping irradiation of light other than during measurement without increasing the size of the apparatus.

  In order to solve the conventional problem, the noninvasive living body information measuring apparatus according to the invention of claim 1 of the present application is a photoacoustic wave generated by a specific substance in the living body absorbing light energy by light irradiated on the living body surface. In a non-invasive living body information measuring device for estimating a feature amount of living body information by detecting a signal, a control means for outputting an irradiation control signal for controlling irradiation of pulse light repeated periodically, the irradiation control signal From the at least one light source for irradiating the surface of the living body with the pulsed light, the photoacoustic detection means for detecting the pulsed light or the photoacoustic wave signal, and the detection signal obtained by the photoacoustic detection means, A feature quantity estimating means for estimating the feature quantity; and a feature quantity display means for displaying the feature quantity of the biological information and the irradiation status of the light source, wherein the feature quantity estimation means is the detection signal. A first measurement position and a second measurement position are extracted, and the control means uses the information on the first measurement position and the information on the second measurement position to generate pulses after the next period of the pulsed light. It is characterized by controlling the irradiation of light and measuring biological information.

  The noninvasive living body information measuring apparatus according to claim 2 of the present application is the noninvasive living body information measuring apparatus according to claim 1, wherein the first measurement position is the pulse when the pulsed light is irradiated. A position of a waveform that appears in the detection signal due to light directly reaching the photoacoustic detection means, and the second measurement position is the position after a predetermined time from the first measurement position. The position of the waveform that appears in the detection signal due to the photoacoustic wave signal from the surface of the living body reaching the photoacoustic detection means, and the control means extracts the first measurement position. If the second measurement position is not extracted after a predetermined time has elapsed, the irradiation of the pulsed light after the next period of the pulsed light is stopped.

  The noninvasive living body information measuring apparatus according to claim 3 of the present application is the noninvasive living body information measuring apparatus according to claim 1, wherein the first measurement position is the pulse when the pulsed light is irradiated. A position of a waveform that appears in the detection signal due to light directly reaching the photoacoustic detection means, and the second measurement position is the position after a predetermined time from the first measurement position. The position of the waveform that appears in the detection signal due to the photoacoustic wave signal from the surface of the living body reaching the photoacoustic detection means, and the control means is predetermined after the irradiation control signal is output. When the second measurement position is not extracted after the elapse of time, the irradiation of the pulsed light after the next period of the pulsed light is stopped.

  The noninvasive living body information measuring device according to claim 4 of the present application is the noninvasive living body information measuring device according to claim 2 or 3, wherein the control means includes a writable register, The register can change the predetermined time from the outside.

  The noninvasive living body information measuring apparatus according to claim 5 of the present application is the noninvasive living body information measuring apparatus according to claim 1, wherein the feature amount estimating means is within one cycle in which the pulsed light is irradiated. The first and second time windows are periodically opened, and the first measurement position is determined by comparing the detection signal with the first threshold while the first time window is open. And the second measurement position is extracted by comparing the detection signal with a second threshold while the second time window is open. .

  A noninvasive living body information measuring device according to a sixth aspect of the present invention is the noninvasive living body information measuring device according to the fifth aspect, wherein the first threshold value and the second threshold value to be compared with the detection signal. Is determined based on the amplitude of the detection signal.

  The noninvasive living body information measuring device according to claim 7 of the present application is the noninvasive living body information measuring device according to claim 5, wherein the first threshold value and the second threshold value to be compared with the detection signal. Is determined based on the slope of the detection signal.

  Further, the noninvasive living body information measuring apparatus according to claim 8 of the present application is the noninvasive living body information measuring apparatus according to claim 5, wherein the feature amount estimating means is configured to start the period when the pulsed light is irradiated. The counter is reset to the first set time, the first time window is opened, and when the value indicated by the counter that counts up with the passage of time thereafter coincides with the second set time, the first 1 time window is closed, the second time window is opened when the value indicated by the counter matches the third set time, and the second time window is set when the value indicated by the counter matches the fourth set time. The second time window is closed.

  The noninvasive living body information measuring apparatus according to claim 9 of the present application is the noninvasive living body information measuring apparatus according to claim 8, wherein the second set time is immediately after the pulsed light is irradiated. A value up to a time point before the third set time is set.

  The noninvasive living body information measuring apparatus according to the invention of claim 10 of the present application is the noninvasive living body information measuring apparatus according to claim 8, wherein the third set time is later than the second set time. In addition, a value up to a time point before the photoacoustic wave signal reaches the photoacoustic detection means is set.

  The noninvasive living body information measuring apparatus according to claim 11 of the present application is the noninvasive living body information measuring apparatus according to claim 8, wherein the photoacoustic wave signal is the photoacoustic signal during the fourth set time. It is characterized in that it is set to a value up to a time point that is later than the time until the detection means is reached and before the period start time of the next pulse light irradiation.

  The noninvasive living body information measuring device according to the invention of claim 12 of the present application is the noninvasive living body information measuring device according to any one of claims 5 to 7, wherein the feature amount estimating means is writable. A plurality of registers, and the first threshold value and the second threshold value can be changed from the outside by each register.

  Further, the noninvasive living body information measuring apparatus according to the invention of claim 13 of the present application is the noninvasive living body information measuring apparatus according to any one of claims 8 to 10, wherein the feature amount estimating means is writable. A plurality of registers, and the second set time and the third set time can be changed from the outside by each register.

  The noninvasive living body information measuring apparatus according to claim 14 of the present application is the noninvasive living body information measuring apparatus according to claim 8 or 11, wherein the feature amount estimating means includes a writable register. And the register can change the fourth set time from the outside.

  Further, the noninvasive living body information measuring apparatus according to claim 15 of the present application is the noninvasive living body information measuring apparatus according to claim 1, wherein the feature amount estimating means attenuates a high frequency component from the detection signal. A filter for outputting a high-frequency attenuation detection signal, and extracting the first measurement position by comparing the high-frequency attenuation detection signal with a first threshold, The second measurement position is extracted by comparing with a threshold value.

  Further, the noninvasive living body information measuring apparatus according to the invention of claim 16 of the present application is the noninvasive living body information measuring apparatus according to claim 1, wherein the control means is configured so that the noninvasive living body information measuring apparatus is correctly attached to a living body. A device mounting detection mode for detecting whether or not the body information is detected, and a biological information measurement mode for measuring a feature amount of the biological information. In the device mounting detection mode, the laser power is set to a first light intensity After irradiating pulsed light and extracting the first measurement position, when the second measurement position can be extracted after the lapse of the predetermined time, the biological information measurement mode is entered. The biometric information is measured by setting the laser power after the next period to the second light intensity.

  Further, the noninvasive living body information measuring device according to the invention of claim 17 of the present application is the noninvasive living body information measuring device according to claim 16, wherein the control means is the first light in the device wearing detection mode. When the second measurement position cannot be extracted after elapse of the predetermined time after the first measurement position is extracted after performing irradiation with the pulsed light with the laser power indicated by the intensity, the irradiation period of the pulsed light It is predetermined that the second measurement position can be extracted after elapse of a predetermined time after extracting the first measurement position while increasing the laser power step by step with the third light intensity as a limit. When the first light intensity is updated with the laser power at that time, the biological information measurement mode is entered. The Pawa is set to the second light intensity is characterized in that the measurement of biological information.

  Further, the noninvasive living body information measuring apparatus according to the invention of claim 18 of the present application is the noninvasive living body information measuring apparatus according to claim 16, wherein the control means has a first light intensity in the apparatus wearing detection mode. When the second measurement position can be extracted after elapse of the predetermined time after irradiating the pulsed light with the laser power indicated by and extracting the first measurement position, the pulsed light irradiation period If the second measurement position cannot be extracted after a lapse of a predetermined time after extracting the first measurement position while gradually decreasing the laser power, the first light intensity is set a predetermined number of times before. After updating with the laser power irradiated to the biological information measurement mode, the biological information measurement mode is set, and in the biological information measurement mode, the laser power after the next period is set to the second light intensity and the biological information is set. It is characterized in making measurements.

  The noninvasive living body information measuring device according to claim 19 of the present application is the noninvasive living body information measuring device according to claim 1, wherein the control means is configured so that the noninvasive living body information measuring device is correctly attached to a living body. A device mounting detection mode for detecting whether or not the body information is detected, and a biological information measurement mode for measuring a feature amount of the biological information. In the device mounting detection mode, the laser power is set to a first light intensity After irradiating pulsed light, after performing irradiation of the pulsed light, when the second measurement position can be extracted after elapse of the predetermined time, the biological information measuring mode is entered, and in the biological information measuring mode, Biometric information is measured by setting the laser power after the next cycle to the second light intensity.

  The noninvasive living body information measuring apparatus according to the invention of claim 20 of the present application is the noninvasive living body information measuring apparatus according to claim 19, wherein the control means has a first light intensity in the apparatus wearing detection mode. If the second measurement position is not extracted after elapse of the predetermined time after irradiating the pulsed light with the laser power indicated by After irradiating the pulsed light while increasing the laser power step by step up to the third light intensity, the second measurement position could be extracted a predetermined number of times after a predetermined time elapsed. In this case, after the first light intensity is updated with the laser power at the time point, the biological information measurement mode is entered, and in the biological information measurement mode, the laser power after the next period is changed. Is set to 2 in the light intensity is characterized in that the measurement of biological information.

  The noninvasive living body information measuring device according to claim 21 of the present application is the noninvasive living body information measuring device according to claim 19, wherein the control means is the noninvasive living body information measuring device according to claim 19. In the apparatus mounting detection mode, the second measurement position is irradiated after the predetermined time has elapsed after the pulse light is irradiated with the laser power indicated by the first light intensity. When the second measurement position cannot be extracted after a predetermined time has elapsed after performing pulsed light irradiation while gradually decreasing the laser power for each pulsed light irradiation period. The first light intensity is updated with the laser power irradiated a predetermined number of times before, and then the biological information measurement mode is entered. In the biological information measurement mode, after the next cycle The Zapawa is set to the second light intensity is characterized in that the measurement of biological information.

  Further, the noninvasive living body information measuring device according to the invention of claim 22 of the present application is the noninvasive living body information measuring device according to any one of claims 16 to 21, wherein the device mounting detection mode is set when the power is turned on. Alternatively, when the non-invasive living body information measuring device is attached to a living body, a device attachment detection mode is set.

  The noninvasive living body information measuring device according to the invention of claim 23 of the present application is the noninvasive living body information measuring device according to any one of claims 16 to 21, wherein the device mounting detection mode is a biological information measuring device. At the start of measurement, the apparatus mounting detection mode is set.

  The noninvasive living body information measuring device according to claim 24 of the present application is the noninvasive living body information measuring device according to any one of claims 16 to 21, wherein the first light intensity is the first light intensity. The light intensity is smaller than the light intensity of 2.

  The noninvasive living body information measuring device according to claim 25 of the present application is the noninvasive living body information measuring device according to claim 17 or 20, wherein the third light intensity is the first light. The intensity is higher than the intensity and lower than the second light intensity.

  Further, the noninvasive living body information measuring apparatus according to the invention of claim 26 of the present application is the noninvasive living body information measuring apparatus according to any one of claims 16 to 21, wherein the control means is a plurality of writable units. The first light intensity, the second light intensity, the third light intensity, and the predetermined number of times can be changed from the outside by each register. It is a feature.

  According to the noninvasive living body information measuring device of the present invention, since irradiation of light other than during measurement can be stopped without increasing the size of the device, living body information can be measured safely and comfortably.

Embodiments of the noninvasive living body information measuring apparatus of the present invention will be described below in detail with reference to the drawings.
The non-invasive living body information measuring device of the present invention is a sensor that detects contact between a living body and a photoacoustic sensor by determining whether irradiation is possible using a photoacoustic wave in order to prevent a crisis such as eyeball damage caused by pulsed light. Is unnecessary.

(Embodiment 1)
In Embodiment 1 of the present invention, the noninvasive biological information measuring device is assumed to be a noninvasive blood sugar measuring device 1 that measures blood sugar levels.

  FIG. 1 is a diagram showing a system configuration according to Embodiment 1 of the present invention.

  In FIG. 1, 1 is a non-invasive blood glucose measurement device, 20 is a light source, 201 is pulsed light, 30 is the surface of a living body, 31 is a blood vessel, 301 is a photoacoustic wave signal, and 40 is a photoacoustic detection means.

  Other components other than the light source 20 and the photoacoustic detection means 40 constituting the noninvasive blood glucose measurement device 1 will be described later.

  FIG. 1A is a diagram showing a system configuration of the noninvasive blood glucose measurement device 1 when the light source 20 and the photoacoustic detection means 40 are installed adjacent to each other on the surface 30 of the living body, that is, the skin. FIG. 3 is a diagram showing a system configuration of the noninvasive blood sugar measurement device 1 when a photoacoustic detection means 40 is installed between the skin and the light source 20.

  The noninvasive blood glucose measurement device 1 is attached so as to be in contact with the surface 30 of the living body, and makes the pulsed light 201 that is the irradiation light of the light source 20 enter the living body. The pulsed light 201 propagates through the living body and is absorbed by glucose in the blood vessel 31 to generate a photoacoustic wave signal 301. The photoacoustic wave signal 301 generated by the glucose in the blood vessel 31 is detected by the photoacoustic detection means 40 in the non-invasive blood glucose measurement device 1 to estimate the blood glucose level as a feature quantity of the biological information.

  In the system configuration of FIG. 1A, a part of the pulsed light 201 emitted from the light source 20 toward the living body (the surface 30) is reflected on the skin surface. The reflected light and the light leaking depending on the degree of contact of the light source 20 with the skin surface reach the photoacoustic detection means 40.

  In the system configuration of FIG. 1B, the pulsed light 201 emitted from the light source 20 passes through the photoacoustic detection means 40 and is applied to the living body (the surface 30 thereof).

  In both the system configurations of FIG. 1A and FIG. 1B, part of the pulsed light 201 is transmitted to the photoacoustic detection means 40 immediately after the pulsed light 201 is irradiated.

  FIG. 2 is a diagram showing a block configuration of the noninvasive blood glucose measurement device 1 according to Embodiment 1 of the present invention.

  In FIG. 2, 10 is a control means, 50 is a feature quantity estimation means, and 60 is a feature quantity display means. These control means 10, light source 20, photoacoustic detection means 40, feature quantity estimation means 50, and feature quantity display means 60. The non-invasive blood sugar measuring device 1 is configured from the above.

  Further, 101 is an irradiation control signal, 401 is a detection signal, 503 is a feature amount estimation signal, 501 is a first measurement position signal, 502 is a second measurement position signal, 102 is an irradiation period signal, and 103 is an error display signal. is there.

  The control means 10 outputs an irradiation control signal 101 for controlling the light irradiation based on the first measurement position signal 501 and the second measurement position signal 502 to the light source 20, and also features an error display signal 103. It outputs to the quantity display means 60. The light source 20 irradiates the living body 300 with the pulsed light 201 in accordance with the irradiation control signal 101.

  The photoacoustic detection means 40 converts the photoacoustic wave signal 301 from the living body 300 into a detection signal 401. The feature quantity estimation means 50 estimates the blood glucose level from the detection signal 401 and sends a feature quantity estimation signal 503 as an estimation result to the feature quantity display means 60. The feature amount display means 60 displays the blood glucose level indicated by the feature amount estimation signal 503 to the user, and when there is an attachment error of the non-invasive blood glucose measurement device 1, the non-invasive blood glucose measurement device using the error display signal 103. 1 mounting error is displayed.

  Here, the photoacoustic detection means 40 detects a pressure based on the photoacoustic wave signal 301 and outputs a detection result as a voltage, a preamplifier that amplifies the signal detected by the piezoelectric sensor, and a signal amplified by the preamplifier. An A / D converter that samples and outputs a detection signal 401 is configured.

  In the system configuration of the first embodiment of the present invention, the following change appears in the detection signal 401 of the photoacoustic detection means 40.

  That is, immediately after the light source 20 irradiates the pulsed light 201, the piezoelectric sensor in the photoacoustic detection means 40 absorbs the energy of a part of the pulsed light 201 that has come directly from the light source 20 or the pulsed light 201 reflected by the surface of the living body. Thus, distortion occurs, and the distortion appears in the detection signal 401 as a change in voltage (hereinafter referred to as a first peak (first measurement position)).

  Next, the photoacoustic wave signal 301 generated by the component contained in the skin surface absorbing the energy of the pulsed light 201 reaches the piezoelectric sensor, and a voltage change occurs in the detection signal 401 (hereinafter, the second peak ( 2nd measuring position)). The second peak appears when time elapses after the first peak occurs until the photoacoustic wave signal 301 propagates from the skin surface to the piezoelectric sensor.

  In the noninvasive blood glucose measurement device 1 of the present invention, the photoacoustic wave signal 301 generated by the glucose in the blood vessel 31 absorbing the energy of the pulsed light 201 is detected by the piezoelectric sensor in the photoacoustic detection means 40, amplified by the preamplifier, and The detection signal 401 is converted by sampling in the A / D converter, and the blood sugar level is estimated from the detection signal 401 in the feature amount estimation means 50.

  For example, when the non-invasive blood sugar measuring device 1 of the present invention is not mounted on the skin, the second peak does not appear or the appearance timing is different from that when it is mounted on the skin. Conversely, when the non-invasive blood glucose measuring device 1 is mounted on the skin, the distance between the piezoelectric sensor and the skin does not change, and therefore the first peak and the second peak are generated at regular time intervals.

  Therefore, the timing at which the first peak and the second peak appear is measured, and the time difference is checked to determine whether or not the noninvasive blood glucose measurement device according to the first embodiment is correctly installed on the skin surface. can do.

  Below, the noninvasive blood glucose measuring apparatus 1 which implement | achieves this judgment is demonstrated.

  FIG. 3 is a block diagram showing the configuration of the feature quantity estimating means 50. As shown in FIG. In FIG. 3, 510 is a sample number counter, 520 is change position detection means, 530 is time window generation means, 540 is measurement position signal generation means, 550 is estimation means, and 560 is a register.

  511 is a sample number count signal, 531 is a time window signal, 521 is a change position pulse, 561 is a first threshold value, 562 is a second threshold value, 563 is a second set time, and 564 is a third set time. 565 is a fourth set time.

  The sample number counter 510 is a counter that is reset by the irradiation period signal 102 input to the feature amount estimation unit 50, counts the number of samplings in the A / D converter in the photoacoustic detection unit 40, and uses the count result as a count result. A certain sample number count signal 511 is output to the measurement position signal generation means 540. The estimation unit 550 estimates the glucose concentration using the detection signal 401 input from the photoacoustic detection unit 40 to the feature amount estimation unit 50 and the irradiation period signal 102 input from the control unit 10, and is an estimation result thereof. The feature amount estimation signal 503 is output to the feature amount display means 60.

  The change position detection unit 520 includes a detection signal 401 input from the photoacoustic detection unit 40, a first threshold value 561 and a second threshold value 562 input from the register 560, and a time input from the time window generation unit 530. A specific change position is detected from the window signal 531 and a change position pulse 521 is output to the measurement position signal generation means 540.

  In the time window generation means 530, the second set time 563, the third set time 564 and the fourth set time 565 output from the register 560, and the sample number count signal 511 output from the sample number counter 510 are used as time. A window signal 531 is created and output to the change position detection means 520.

  In the measurement position signal generation means 540, the first measurement position is obtained from the sample number count signal 511 from the sample number counter 510, the change position pulse 521 from the change position detection means 520, and the fourth set time 565 from the register 560. A signal 501 and a second measurement position signal 502 are generated and output to the control means 10.

  Next, the operation of the feature quantity estimating means 50 will be described with reference to FIG. FIG. 4 is a timing chart showing the operation in the feature quantity estimating means 50.

  4, (a) is an irradiation period signal 102, (b) is a detection signal 401, (c) is a sample number count signal 511, (d) is a time window signal 531 and (e) is a change position pulse 521. . The pulsed light 201 is emitted every pulse generation period of the irradiation period signal 102, and the sample number count signal 511 is reset to “0” (TA, TG). The sample number counter 510 counts up according to the sampling timing of the detection signal 401.

  The time window signal 531 opens at the start of the pulse generation cycle (TA, TG), and closes when the sample count signal 511 reaches the second set time 563 (TC). After that, when the sample number count signal 511 reaches the third set time 564, it opens again (TD), and when it reaches the fourth set time 565, it closes (TF).

  The opening / closing timing of the time window is set as follows.

  First, the first peak (corresponding to TB in the figure) of the detection signal 401 is generated when the pulsed light 201 irradiated by the light source 20 is reflected by the surface of the living body and enters the photoacoustic detection means 40. Since it occurs immediately after the light 201 is irradiated, the second set time 563 is after the irradiation time of the pulsed light (first set time) and the photoacoustic wave signal 301 reaches the piezoelectric sensor from the skin. Set before the time until.

  The second peak (corresponding to TE in the figure) of the detection signal 401 is generated when a photoacoustic wave generated on the living body surface by the pulsed light 201 irradiated by the light source 20 enters the photoacoustic detection means 40. Since the photoacoustic wave signal 301 is generated after the pulse light 201 is irradiated and reaches the piezoelectric sensor, the third set time 564 is after the second set time 563 and is photoacoustic. The time is set before the wave signal 301 propagates from the skin to the piezoelectric sensor.

  The fourth set time 565 is after the time when the photoacoustic wave signal 301 propagates between the skin and the piezoelectric sensor and before the next irradiation period signal 102 is generated. Set to.

  The change position detecting means 520 compares the detection signal 401 while the first time window is open with the first threshold value 561, and the absolute value of the amplitude at the first peak is the maximum when the first threshold value 561 is exceeded. The change position pulse 521 is generated at the timing (TB). Similarly, the detection signal 401 while the second time window is open is compared with the second threshold value 562, and changes at the timing when the absolute value of the amplitude at the second peak becomes the maximum at the second threshold value 562 or more. A position pulse 521 is generated (TE).

  In the measurement position signal generation means 540, the sample number count signal 511 at the timing when the change position pulse 521 is generated is held by a flip-flop circuit (not shown), and the second time window signal 531 is closed (TF). The first measurement position signal 501 and the second measurement position signal 502 are output to the control means 10. Here, the first measurement position signal 501 is a signal obtained from the first peak, and the second measurement position signal 502 is a signal obtained from the second peak.

  If the detection signal 401 during the second time window is not opened does not exceed the second threshold value 562, the second measurement position signal 502 is a measurement NG, that is, a signal indicating that the measurement has failed. Become. The measurement NG can be expressed by assigning the maximum number of the countable range of the sample number count signal 511, for example.

  The above operations are summarized as follows with reference to FIG.

  FIG. 5 is a flowchart showing an operation of irradiating or stopping the pulsed light depending on whether or not the non-invasive living body information measuring apparatus 1 is in a correct wearing state.

  In FIG. 5, S1 is a step for setting the generation timing of the time window, S2 and S3 are steps for detecting the peak of the detection signal, S4 is a step for determining whether or not the peak detection is successful, and S5 is a time difference between the peaks. Detecting step, S6 determining whether or not the time difference matches a predetermined value, S7 allowing pulsed light irradiation, S8 generating a measurement NG signal, and S9 stopping pulsed light irradiation It is a step to do.

  First, in step S1, timings for generating the first and second time windows are set. Next, in step S2, the peak of the detection signal is detected within the first time window, and then in step S3, the peak of the detection signal is detected within the second time window.

  Next, in step S4, it is determined whether or not the peak detection within the second time window has succeeded. If successful, in step S5, the time difference between the peak detected within the first time window and the peak detected within the second time window is measured.

  In step S6, it is determined whether or not the time difference matches a predetermined value. If they match, pulsed light irradiation is permitted in step S7. If not coincident, the irradiation of the pulsed light is stopped in step S9.

  If the peak detection within the second time window fails in step S4, a measurement NG signal is generated in step S8. Also in this case, the irradiation of the pulsed light is stopped in step S9.

  Next, control of the light source 20 using the first measurement position signal 501 and the second measurement position signal 502 will be described with reference to FIG.

  FIG. 6 is a block diagram showing the configuration of the control means 10. In FIG. 6, 110 is a subtracting means, 120 is an irradiation determining means, 130 is an irradiation signal generating means, 140 is an irradiation period counter, and 150 is a register. 111 is a measurement position subtraction signal, 151 is a predetermined time signal, and 121 is an irradiation determination signal.

  The subtracting unit 110 subtracts the second measurement position signal 502 from the first measurement position signal 501 input from the feature amount estimation unit 50 (the reverse may be the case), and converts it to the measurement position subtraction signal 111. And output to the irradiation determination means 120. The irradiation determination unit 120 compares the measurement position subtraction signal 111 with the predetermined time signal 151 input from the register 150 to determine whether or not to perform irradiation in the next irradiation cycle, and generates an irradiation determination signal 121 as an irradiation signal. It outputs to the means 130.

  The irradiation period counter 140 generates an irradiation period signal 102 for each irradiation period of the pulsed light 201 and outputs it to the irradiation signal generation unit 130 and the feature amount estimation unit 50. The irradiation signal generation unit 130 creates an irradiation control signal 101 from the irradiation cycle signal 102 and the irradiation determination signal 121 and outputs the irradiation control signal 101 to the light source 20.

  The predetermined time signal 151 corresponds to a time during which the photoacoustic wave signal 301 propagates from the skin to the piezoelectric sensor, and is set in the register 150 in advance. This set value is a value determined by the propagation speed inherent to the medium through which the ultrasonic wave propagates in the medium that fills between the skin and the piezoelectric sensor, and the thickness of the medium.

  Next, the operation of the control means 10 will be described. The subtracting unit 110 obtains a difference between the first measurement position signal 501 and the second measurement position signal 502. However, when the second measurement position signal 502 represents measurement NG, the measurement position subtraction signal 111 is a signal representing measurement NG.

  If the non-invasive blood glucose measurement device is correctly placed on the skin, the interval between the first peak and the second peak of the detection signal 401 is constant, and the measurement position subtraction signal 111 is a value indicated by the predetermined time signal 151. Is equal to Therefore, the irradiation determining means 120 determines that the photoacoustic wave signal 301 obtained from the skin surface has been normally obtained if the measurement position subtraction signal 111 is equal to the value indicated by the predetermined time signal 151, and in the next irradiation cycle. An irradiation determination signal 121 that permits irradiation of the pulsed light 201 is output.

  At this time, when the measurement position subtraction signal 111 indicates measurement NG or when the measurement position subtraction signal 111 is outside the range indicated by the signal 151 for a predetermined time, it is determined that the photoacoustic wave signal 301 is not obtained from the skin surface. Then, an irradiation determination signal 121 for stopping the irradiation of the pulsed light 201 in the next irradiation cycle is output. Further, when the irradiation of the pulsed light 201 in the next irradiation cycle is stopped, the error display signal 103 is output to the feature amount display means 60.

  When comparing the measurement position subtraction signal 111 and the predetermined time signal 151, the non-invasive blood glucose measurement device 1 may compare with a margin corresponding to the amount of deviation within an allowable range with respect to the skin.

  The irradiation signal generation unit 130 issues an instruction for irradiation of the pulsed light 201 to the light source 20 only when the irradiation determination signal 121 permits irradiation at the pulse generation timing of the irradiation period signal 102 described above.

  Here, the change position detection unit 520 generates the change position pulse 521 using the maximum absolute value of the amplitude of the first peak and the second peak of the detection signal 401. The change position pulse 521 may be generated using the gradient of the amplitude absolute value. In this case, it is only necessary to detect a position where the rising slope is the maximum at each peak.

  Further, the feature amount estimating means 50 can also create the first measurement position signal 501 from the irradiation control signal 101. The operation of the feature quantity estimation means 50 in this case will be described using the timing chart of FIG.

  7, (a) is an irradiation period signal 102, (b) is an irradiation control signal 101, (c) is a detection signal 401, (d) is a sample count signal 511, (e) is a time window signal 531, ( f) is a change position pulse 521.

  After the pulse generation (TA) of the irradiation period signal 102, a pulse of the irradiation control signal 101 is generated (TH), and the pulsed light 201 is emitted from the light source 20. Since the first peak occurs immediately after irradiation of the pulsed light 201, the first peak is detected even if the first measurement position signal 501 is generated from the sample count signal 511 at the timing when the pulse of the irradiation control signal 101 is generated. Compared to the case, the timing does not change greatly.

  The second measurement position signal 502 uses a time window that opens only between the third set time 564 and the fourth set time 565, as described above, and the detection signal 401 while the time window is open. And the second threshold value 562 are compared to generate a change position pulse 521 (TE), and the sample count signal 511 at the timing when the change position pulse 521 is generated is used.

  In this case, since the first peak is not used to create the first measurement position signal 501, the time window signal 531 only needs to satisfy the condition for opening only with respect to the second peak.

  The above operations are summarized as follows with reference to FIG.

  FIG. 8 is a flowchart showing another operation of irradiating or stopping the pulsed light depending on whether or not the non-invasive living body information measuring apparatus 1 is in a correct wearing state.

  In FIG. 8, S11 is a step of setting the generation timing of the time window, S12 is a step of detecting the generation timing of the irradiation control signal, S13 is a step of detecting the peak of the detection signal, and S14 is whether or not the peak detection is successful. A step of determining, S15 is a step of detecting a time difference from the generation timing of the irradiation control signal to the detected peak, S16 is a step of determining whether or not the time difference matches a predetermined value, and S17 permits irradiation of pulsed light. Step S18 is a step of generating a measurement NG signal, and S19 is a step of stopping the irradiation of pulsed light.

  First, in step S19, the generation timing of a time window corresponding to the second detection signal peak is set. Next, in step S12, the generation timing of the irradiation control signal is detected. Thereafter, in step S3, the peak of the detection signal within the time window is detected.

  Next, in step S14, it is determined whether or not the peak detection within the time window has succeeded. If successful, in step S15, the time difference from the generation timing of the irradiation control signal to the peak detected in the time window is measured.

  In step S16, it is determined whether or not the time difference matches a predetermined value. If they match, pulsed light irradiation is permitted in step S17. If not coincident, the irradiation of the pulsed light is stopped in step S19.

  If the peak detection within the time window fails in step S14, a measurement NG signal is generated in step S18. Also in this case, the irradiation of the pulsed light is stopped in step S19.

  In this case, for example, in FIG. 2A, it is effective in compensating for the difficulty in detecting the first measurement position due to the reduction of leakage light accompanying the optimization of the irradiation efficiency of the light source 20.

  As described above, according to the first embodiment, by providing the control means 10 and the feature amount estimation means 50, it can be determined from the detection signal 401 whether or not the non-invasive blood glucose measurement device is normally installed. Therefore, the function of stopping the irradiation of the pulsed light 201 when the apparatus is not properly mounted can be realized without requiring a separate detector.

(Embodiment 2)
FIG. 9 is a block diagram showing the configuration of the control means 11 of the non-invasive blood sugar measurement device according to Embodiment 2 of the present invention. The control means 11 replaces the control means 10 in FIG.

  Note that various components (such as various signals, various blocks, and various circuits) of the noninvasive blood glucose measurement device according to the second embodiment of the present invention are the same as those components unless otherwise described in the second embodiment. It shall have a function equivalent to the component of Embodiment 1 which has a name, and detailed description is abbreviate | omitted.

  In FIG. 9, reference numeral 160 denotes mode management means. Also, 161 is a light intensity control signal, 152 is a signal a predetermined number of times, 153 is a first light intensity signal, 154 is a second light intensity signal, and 155 is a third light intensity signal.

  The mode management unit 160 includes an irradiation period signal 102 input from the irradiation period counter 140, an irradiation determination signal 121 input from the irradiation determination unit 120, a first light intensity signal 153 input from the register 150, The light intensity control signal 161 is generated from the second light intensity signal 154, the third light intensity signal 155, and the predetermined number of times of the signal 152, and is output to the irradiation signal generating means 130.

  FIG. 10 is a timing chart showing the operation of the control means 11.

  10, (a) is an irradiation period signal 102, (b) is an irradiation control signal 101, (c) is a detection signal 401, (d) is a change position pulse 521, and (e) is a device mounting detection mode or biological information. It is a figure which shows a measurement mode, and a laser power becomes large and the variation | change_quantity of the detection signal 401 becomes large, so that the amplitude of the irradiation control signal 101 is large.

  FIG. 11 is a flowchart showing the transition of the operation mode of the non-invasive blood sugar measurement device.

  In FIG. 11, S21 is a step for determining whether or not the apparatus is correctly mounted, S22 is a step for branching the next operation according to the determination result, S23 is a step for shifting to the biological information measurement mode, and S24 is a pulsed light. This is a step of stopping the irradiation.

  Hereinafter, the operation of the control means 11 will be described with reference to FIGS.

  First, the mode at the time of power-on or the start of measurement is set to the device attachment detection mode (MODEA). The device attachment detection mode is a mode (step S21 in FIG. 11) for detecting whether or not the device is correctly attached to a living body, and the laser power is suppressed to be small in order to prevent damage to the eyeball and the like. . In the apparatus mounting detection mode, the laser power of the pulsed light 201 controlled by the irradiation control signal 101 is set by the first light intensity signal 153.

  Then, after the pulse generation (TA) of the irradiation cycle signal 102, the pulse of the irradiation control signal 101 is generated and the pulsed light 201 is irradiated (TH). Next, a first peak is detected from the detection signal 401 and a change position pulse 521 is generated (TB).

  Thereafter, the second peak is detected from the detection signal 401 (TE), and the first measurement position signal 501 and the second measurement position signal 502 are compared with the signal 151 for a predetermined time so that the apparatus is correctly placed on the skin surface. It is determined whether or not there is (step S22 in FIG. 11).

  In the second embodiment, thereafter, the first measurement position signal 501, the second measurement position signal 502, and the predetermined time signal 151 are used to determine whether or not the apparatus is correctly installed on the skin surface. The result (irradiation determination signal 121) is expressed as next irradiation OK and next irradiation NG.

  If the next irradiation is OK, the mode is switched to the biological information measurement mode (MODEB) (step S23 in FIG. 11). This mode switching is performed from the detection of the second peak until the next irradiation cycle signal 102 is generated (TE to TG).

  When the biological information measurement mode is entered, the laser power of the pulsed light 201 irradiated thereafter is set by the second light intensity signal 154 and irradiated (TI). Then, the next irradiation OK or the next irradiation NG is determined every measurement, and when the next irradiation NG is reached, the irradiation of the pulsed light 201 is stopped as described in the first embodiment (step S24 in FIG. 11). At the same time, the user is notified of the error.

  Since the first light intensity signal 153 may be set to a level at which the first peak and the second peak can be detected at a minimum, the first light intensity signal 153 is set to a level smaller than the second light intensity signal 154. The second light intensity signal 154 is set to a level at which the change amount of the detection signal 401 corresponding to the change in the glucose amount in the blood can be detected.

  Switching from the device attachment detection mode to the biological information measurement mode may be performed as follows. FIG. 12 is a timing chart showing another operation for controlling the laser power of the pulsed light 201.

  In FIG. 12, (a) is an irradiation cycle signal 102, (b) is an irradiation control signal 101, (c) is a change position pulse 521, (d) is an irradiation determination signal 121, and (e) is a device wearing detection mode or a living body. It is a figure which shows information measurement mode.

  FIG. 13 is a flowchart showing the transition of the operation mode of the noninvasive blood glucose measurement device.

  In FIG. 13, S31 is a step for determining whether or not the next irradiation is possible, S32 is a step for branching the next operation according to the determination result, S33 is a step for irradiating a laser, and S34 is for increasing the next laser power. It is a step to do.

  First, the mode when the power is turned on or the measurement is started is set to the apparatus mounting detection mode (MODEA), and the laser power of the pulsed light 201 is set to the first light intensity signal 153. TA, TG, TJ, TK, and TL are irradiation period signals 102 indicating the respective irradiation periods.

  Then, after the pulse generation (TA) of the irradiation period signal 102, the pulse of the irradiation control signal 101 is generated and the pulsed light 201 is irradiated (TM). At this time, the laser power of the pulsed light 201 has a magnitude indicated by POWA in the drawing.

  Next, the next irradiation OK or NG is determined based on the change position pulse 521 extracted from the detection signal 401 (step S31 in FIG. 13). As shown in FIG. 12, when the next irradiation NG is determined for the pulsed light 201 emitted during the pulsed light 201 generation period TA-TG (step S32 in FIG. 13), the laser power of the next pulsed light 201 is set to POWB. Irradiation is increased (TN) (step S34 in FIG. 13).

  In the irradiation of the pulsed light 201 whose laser power is POWB, if it is determined that the next irradiation is NG, the laser power is increased so that it becomes POWC at the next irradiation (TO), and the laser power to be irradiated next is determined. To do.

  At this time, if it is determined that the next irradiation is OK (TP) (step S32 in FIG. 13), the counter provided in the mode management means 160 is reset and count-up is started. Then, the laser power of the pulsed light 201 to be irradiated next is increased to POWD (TQ) (step S33 in FIG. 13).

  Here, the mode is switched to the biological information measurement mode when irradiation OK is determined continuously for the number of times indicated by the predetermined number of times signal 152 set in advance. In this case, the predetermined number of times set is two.

  In the biological information measurement mode, the laser light of the irradiated pulsed light 201 is set to the second light intensity signal 154 for irradiation (TQ, TR). Then, the next irradiation OK or the next irradiation NG is determined every measurement, and when the next irradiation NG is reached, the irradiation of the pulsed light 201 is stopped as in the case described above, and an error is notified to the user.

  Here, when the value of the first light intensity signal 153 is updated by using the laser power (POWC) of the pulsed light 201 irradiated immediately before at the timing of shifting to the biological information measurement mode, the apparatus mounting detection mode is entered again. In this case, the step of increasing the laser power of the pulsed light 201 step by step eliminates the trouble of searching for the optimal laser power that will be used for the next irradiation. It is possible to adaptively set the laser power of the pulsed light 201 for confirming the above. In this case, it is desirable to set the first light intensity signal 153 as close to “0” as possible.

  In addition, when the laser power of the pulsed light 201 is increased stepwise in the apparatus attachment detection mode, it is possible to prevent the level from reaching the level greater than the second light intensity signal 154 by providing an upper limit value. In the second embodiment, the irradiation with the pulsed light 201 in the device attachment detection mode does not estimate the blood glucose level, but simply determines whether or not the device is normally installed. It is not necessary to make it larger than the laser power of the pulsed light 201 in the biological information measurement mode. Therefore, the upper limit value of the laser power in the apparatus mounting detection mode is set in advance as the third light intensity signal 155. Specifically, it may be set to a level smaller than the second light intensity signal 154.

  So far, in the apparatus mounting detection mode, the case where the laser power is optimally set by increasing the laser power of the pulsed light 201 stepwise has been described. However, the laser power of the pulsed light 201 is stepwise for each irradiation period. You may make it reduce to.

  Specifically, the first light intensity signal 153 is set to a level close to the second light intensity signal 154 in advance, and the next irradiation is performed while gradually decreasing the laser power each time the pulse light 201 is irradiated. The determination of OK or NG is performed each time, and when the next irradiation NG is determined, the first light intensity signal 153 is updated using the laser power irradiated before the number of times indicated by the signal 152, and the biological information measurement is performed. Move to mode.

  As described above, in the second embodiment, the control unit 11 and the feature amount estimation unit 50 are provided, and the laser power in the device attachment detection mode is changed by switching between the device attachment detection mode and the biological information measurement mode. Since it can be set to the minimum, it is possible to minimize the danger due to the irradiation of the pulsed light 201 other than during measurement of the feature amount of the biological information.

  In the second embodiment, the first measurement position signal 501 may be generated from the first peak portion of the detection signal 401 or generated using the irradiation control signal 101.

  In the second embodiment, the non-invasive blood glucose measurement device is mounted on the living body using only the photoacoustic detection means 40, but can be used in combination with other mounting detection.

  Note that the change position detection means 520 in the first or second embodiment detects the second peak from the input detection signal 401, but a low-pass filter (not shown) provided in the change position detection means 520. You may make it detect a 2nd peak from the detection signal 401 which performed the filtering process which attenuates a high frequency region. In this case, even if noise having a high frequency component (for example, pulse noise) is included in the detection signal 401, the second measurement position signal 502 can be detected correctly.

  Note that the target to be measured by the noninvasive blood glucose measurement device according to the first or second embodiment is not limited to the amount of glucose in the blood vessel. That is, any substance that absorbs energy in the wavelength region of the irradiated pulsed light 201 and generates a photoacoustic wave may be used. For example, glucose contained in tissue fluid from the skin surface to the blood vessel, hemoglobin in the blood vessel, and the like. It can also be applied to.

  As described above, the noninvasive living body information measuring device according to the present invention can stop the irradiation of light other than during measurement without increasing the size of the device by utilizing the characteristics included in the photoacoustic signal. Therefore, the biological information can be measured safely and comfortably.

The block diagram which shows the structure of the noninvasive biological information measuring device 1 in Embodiment 1 of this invention. The figure which shows the usage example of the noninvasive biological information measuring device 1 in Embodiment 1 of this invention. The block diagram which shows the structure of the feature-value estimation means 50 in Embodiment 1 of this invention. The figure which shows the timing chart which shows the operation | movement of the feature-value estimation means 50 in Embodiment 1 of this invention. The flowchart figure which shows the operation | movement which performs irradiation or a stop of pulsed light according to whether the noninvasive biological information measuring device 1 in Embodiment 1 of this invention is a correct mounting state. The block diagram which shows the structure of the control means 10 in Embodiment 1 of this invention. The figure which shows the timing chart which shows another operation | movement of the feature-value estimation means 50 in Embodiment 1 of this invention. The flowchart figure which shows the other operation | movement which performs irradiation or a stop of pulsed light according to whether the non-invasive biological information measuring device 1 in Embodiment 1 of this invention is a correct mounting state. The block diagram which shows the structure of the control means 11 in Embodiment 2 of this invention. The figure which shows the timing chart which shows the operation | movement of the control means 11 in Embodiment 2 of this invention. The flowchart figure which shows the operation | movement which the non-invasive biological information measuring device 1 in Embodiment 2 of this invention transfers from apparatus mounting | wearing detection mode to biological information measurement mode. The figure which shows the timing chart which shows another operation | movement of the control means 11 in Embodiment 2 of this invention. The flowchart figure which shows the other operation | movement from which the noninvasive biological information measuring device 1 in Embodiment 2 of this invention transfers to apparatus information detection mode from apparatus mounting | wearing detection mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Control means 11 Control means 20 Light source 30 Living body surface 31 Blood vessel 40 Photoacoustic detection means 50 Feature quantity estimation means 60 Feature quantity display means 101 Irradiation control signal 102 Irradiation period signal 103 Error display signal 110 Subtraction means 111 Measurement position subtraction signal 120 Irradiation determination means 121 Irradiation determination signal 130 Irradiation signal generation means 140 Irradiation cycle counter 150 Register 151 Predetermined time signal 152 Predetermined number of times signal 153 First light intensity signal 154 Second light intensity signal 155 Third light intensity signal 160 Mode management Means 161 Light intensity control signal 201 Pulse light 300 Living body 301 Photoacoustic wave signal 401 Detection signal 501 First measurement position signal 502 Second measurement position signal 503 Feature amount estimation signal 510 Sample number counter 511 Sample number count signal 520 Variable Position detection means 521 Change position pulse 530 Time window generation means 531 Time window signal 540 Measurement position signal generation means 550 Estimation means 560 Register 561 First threshold 562 Second threshold 563 Second set time 564 Third set time 565 4th set time S1-S9 step S11-S19 step S21-S24 step S31-S34 step

Claims (26)

In a non-invasive living body information measuring apparatus that estimates a feature amount of living body information by detecting a photoacoustic wave signal emitted by a specific substance in the living body absorbing light energy by light irradiated on the living body surface,
Control means for outputting an irradiation control signal for controlling irradiation of pulsed light that is repeated periodically;
At least one light source for irradiating the surface of the living body with the pulsed light by the irradiation control signal;
Photoacoustic detection means for detecting the pulsed light or the photoacoustic wave signal;
Feature quantity estimation means for estimating the feature quantity of the biological information from the detection signal obtained by the photoacoustic detection means;
A feature amount display means for displaying a feature amount of the biological information and an irradiation state of the light source;
The feature amount estimation means extracts a first measurement position and a second measurement position from the detection signal,
The control means controls the irradiation of the pulsed light after the next period of the pulsed light using the information on the first measuring position and the information on the second measuring position, and measures biological information.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The first measurement position is a position of a waveform that appears in the detection signal due to the pulse light reaching the photoacoustic detection means directly when the pulse light is irradiated,
The second measurement position appears in the detection signal due to a photoacoustic wave signal from the living body surface reaching the photoacoustic detection means after a predetermined time has elapsed from the first measurement position. The position of the waveform,
If the second measurement position is not extracted after a lapse of a predetermined time from the extraction of the first measurement position, the control means irradiates pulse light after the next period of the pulse light. Stop,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The first measurement position is a position of a waveform that appears in the detection signal due to the pulse light reaching the photoacoustic detection means directly when the pulse light is irradiated,
The second measurement position appears in the detection signal due to a photoacoustic wave signal from the living body surface reaching the photoacoustic detection means after a predetermined time has elapsed from the first measurement position. The position of the waveform,
The control means stops the irradiation of the pulsed light after the next period of the pulsed light when the second measurement position is not extracted after a predetermined time has elapsed after the irradiation control signal is output. ,
A noninvasive living body information measuring device characterized by the above. In the noninvasive living body information measuring device according to claim 2 or 3,
The control means includes
It has a writable register,
The predetermined time can be changed from the outside by the register.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The feature amount estimating means includes:
The first and second time windows are periodically opened within one period in which the pulsed light is irradiated,
The first measurement position is extracted by comparing the detection signal with a first threshold while the first time window is open,
The second measurement position is extracted by comparing the detection signal with a second threshold while the second time window is open.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 5,
The first threshold value and the second threshold value to be compared with the detection signal are:
Determined based on the amplitude of the detection signal,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 5,
The first threshold value and the second threshold value to be compared with the detection signal are:
Determined based on the slope of the detection signal,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 5,
The feature amount estimating means includes:
Reset the counter to a first set time, which is the start of the period during which the pulsed light is emitted, to open the first time window;
When the value indicated by the counter that counts up with respect to the passage of time thereafter coincides with the second set time, the first time window is closed,
When the value indicated by the counter matches a third set time, the second time window is opened;
Closing the second time window when the value indicated by the counter matches a fourth set time;
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 8,
The second set time is
Set to a value from immediately after the pulsed light is irradiated to a time point before the third set time,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 8,
The third set time is set to a value up to a time point after the second set time and before the photoacoustic wave signal reaches the photoacoustic detection means.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 8,
The fourth set time is later than the time until the photoacoustic wave signal reaches the photoacoustic detection means, and until the time point before the period start time when the next pulsed light is irradiated. Set to the value of
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to any one of claims 5 to 7,
The feature amount estimating means includes:
It has multiple registers that can be written,
It is possible to change the first threshold value and the second threshold value from the outside by respective registers.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to any one of claims 8 to 10,
The feature amount estimation means includes:
It has multiple registers that can be written,
The second set time and the third set time can be changed from the outside by respective registers.
A noninvasive living body information measuring device characterized by the above. In the noninvasive living body information measuring device according to claim 8 or 11,
The feature amount estimating means includes:
It is possible to change the fourth set time from the outside by using a register capable of writing.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The feature amount estimating means includes:
A filter that outputs a high-frequency attenuation detection signal obtained by attenuating a high-frequency component from the detection signal;
Extracting the first measurement position by comparing the high-frequency attenuation detection signal with a first threshold;
Extracting the second measurement position by comparing the high-frequency attenuation detection signal with a second threshold;
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The control means includes
A device attachment detection mode for detecting whether or not the non-invasive biological information measurement device is correctly attached to a living body, and a biological information measurement mode for measuring a feature amount of biological information,
In the device wearing detection mode, the laser power is set to the first light intensity and the pulsed light is irradiated,
After extracting the first measurement position, if the second measurement position can be extracted after elapse of the predetermined time, the process proceeds to the biological information measurement mode,
In the biological information measurement mode, the biological information is measured by setting the laser power after the next cycle to the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 16,
The control means includes
In the apparatus mounting detection mode, the pulsed light is irradiated with the laser power indicated by the first light intensity, and after extracting the first measurement position, the second measurement position is determined after the predetermined time has elapsed. If extraction has failed, the first measurement position is extracted while the laser power is increased step by step for each irradiation period of the pulsed light, with the third light intensity as a limit. When it is possible to extract the second measurement position for a predetermined number of times, the first light intensity is updated with the laser power at the time, and then the biological information measurement mode is entered.
In the biological information measurement mode, the biological information is measured by setting the laser power after the next cycle to the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 16,
The control means includes
In the apparatus mounting detection mode, the pulsed light is irradiated with the laser power indicated by the first light intensity, and after extracting the first measurement position, the second measurement position is extracted after the predetermined time has elapsed. In the case where the second measurement position cannot be extracted after a predetermined time elapses after the first measurement position is extracted while gradually reducing the laser power for each irradiation period of the pulsed light , After updating the first light intensity with the laser power irradiated a predetermined number of times before moving to the biological information measurement mode,
In the biological information measurement mode, the biological information is measured by setting the laser power after the next cycle to the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The control means includes
A device attachment detection mode for detecting whether or not the non-invasive biological information measurement device is correctly attached to a living body, and a biological information measurement mode for measuring a feature amount of biological information,
In the device wearing detection mode, the laser power is set to the first light intensity and the pulsed light is irradiated,
After performing the irradiation of the pulsed light, if the second measurement position can be extracted after the predetermined time has elapsed, the process proceeds to the biological information measurement mode,
In the biological information measurement mode, the biological information is measured by setting the laser power after the next cycle to the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 19,
The control means includes
In the apparatus mounting detection mode, the second measurement position is extracted after the predetermined time elapses after the pulsed light is irradiated with the laser power indicated by the first light intensity. If not, the second measurement is performed after a predetermined time has elapsed after irradiating the pulsed light while increasing the laser power stepwise for each irradiation period of the pulsed light up to the third light intensity. When it has been possible to extract the position for a predetermined number of times, the first light intensity is updated with the laser power at the time point, and then the biological information measurement mode is entered.
In the biological information measurement mode, the biological information is measured by setting the laser power after the next cycle to the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 19,
The control means includes
In the apparatus mounting detection mode, the second measurement position is extracted after the predetermined time elapses after the pulsed light is irradiated with the laser power indicated by the first light intensity. If the second measurement position can no longer be extracted after elapse of a predetermined time after irradiating the pulsed light while reducing the laser power step by step for each irradiation period of the pulsed light, After updating the first light intensity with the laser power irradiated a predetermined number of times before, the biological information measurement mode,
In the biological information measurement mode, the biological information is measured by setting the laser power after the next cycle to the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to any one of claims 16 to 21,
When the power is turned on or when the noninvasive biological information measuring device is attached to a living body, the device attachment detection mode is set.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to any one of claims 16 to 21,
The device wearing detection mode is
When the measurement of biological information is started, the device attachment detection mode is set.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to any one of claims 16 to 21,
The first light intensity is a value smaller than the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 17 or 20,
The third light intensity is higher than the first light intensity and lower than the second light intensity.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to any one of claims 16 to 21,
The control means includes
A plurality of writable registers are provided, and the first light intensity, the second light intensity, the third light intensity, and the predetermined number of times can be changed from the outside by each register. Is possible,
A noninvasive living body information measuring device characterized by the above.

Images