JP2014057719A - Organism action measuring apparatus and organism action measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organism action measuring apparatus and an organism action measuring method which are capable of accurately obtaining an organism action by improving measurement accuracy and analysis accuracy.SOLUTION: An organism action measuring apparatus 101 measures an organism action on the basis of a change of light transmitted in an optical fiber 3 due to pressure applied to the optical fiber 3. The organism action measuring apparatus 101 includes: an emitter 21 for outputting light to the optical fiber 3; and a setting part 23 for setting light emission intensity of the emitter 21. A setting value of the light emission intensity set by the setting part 23 is changeable.

Description

  The present invention relates to a living body motion measuring apparatus and a living body motion measuring method, and more particularly to a living body motion measuring apparatus and a living body motion measuring method for measuring a movement of a living body based on a change in transmitted light due to pressure applied to an optical fiber.

  Sensors have been developed that detect changes in pressure on the bedding due to breathing during sleep using an optical fiber laid between the top of the bedding and the human body, and measure apnea sleep conditions and the like.

  As an example of such a sensor, for example, Japanese Unexamined Patent Application Publication No. 2007-144070 (Patent Document 1) discloses the following technique. That is, a change in the transmission optical signal or a change in the reflected light due to excess loss caused by the side pressure applied to the optical fiber is measured. Furthermore, a plastic optical fiber is used as an optical fiber in which the change in the transmission optical signal or the change in the reflected light due to the excess loss caused by the lateral pressure becomes larger.

Japanese Patent Laid-Open No. 2010-131340 (Patent Document 2) discloses the following technique. That is, optical fiber meanders between those using a breathable sponge structure or mesh structure insole mat, or both, and changes in the transmitted optical signal due to excess loss caused by side pressure applied to the optical fiber Enable measurement.

JP 2007-144070 A JP 2010-131340 A

  In such a sensor using an optical fiber, if the quality of the transmitted light of the optical fiber deteriorates, the measurement accuracy decreases and it becomes difficult to accurately measure the movement of the living body. Is done. In particular, higher measurement accuracy is required when attempting to measure not only breathing but also heartbeats that have a shorter cycle than breathing.

  In addition, in a sensor for detecting the movement of a living body, such as a sensor using an optical fiber as described above, as a movement of the living body, for example, not only respiration but also a heartbeat with a shorter cycle than respiration is measured. Therefore, a technique for appropriately analyzing the output signal of the sensor is desired.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a biological motion measuring device capable of accurately obtaining a movement of a biological body by improving measurement accuracy or analysis accuracy. And a biological motion measurement method.

  (1) A living body motion measuring apparatus according to an aspect of the present invention is a living body motion measuring apparatus for measuring movement of a living body based on a change in light transmitted through an optical fiber due to pressure applied to the optical fiber. A light emitter for outputting light to the optical fiber and a setting unit for setting the light emission intensity of the light emitter, and the setting value of the light emission intensity in the setting unit can be changed.

  As described above, the configuration in which the light emission intensity of the light emitter can be set and changed makes it possible to adjust the light emission signal according to variations in the light emitter, the light receiver, the optical fiber, and the like. That is, since the intensity of the received light signal in each living body motion measurement device can be maximized and uniform, the quality of the transmitted light can be improved and the measurement accuracy can be improved. Therefore, the movement of the living body can be accurately obtained by improving the measurement accuracy.

  (2) Preferably, the biological movement measuring device further includes a drive unit for driving the light emitter according to the set value, and the drive unit supplies a direct current as a drive current to the light emitter.

  Such a configuration makes it easy to perform filter processing on the intensity of light transmitted through the optical fiber, that is, the received light signal indicating the amount of received light. For example, from the received light signal to the light emitter, light receiver, optical fiber, etc. It is possible to remove low-frequency components such as drift associated with long- and medium-term characteristic fluctuations, and it is possible to obtain more accurate results in the analysis of biological motion.

  (3) Preferably, the living body motion measurement apparatus further includes a drive unit for driving the light emitter according to the set value, and the drive unit supplies a pulsed current as a drive current to the light emitter. To do.

  As described above, the configuration using the pulsed current allows the maximum instantaneous value of the light emission amount of the light emitter to be allowed to be larger than that in the case where light is continuously output, thereby improving the quality of the transmitted light. The measurement accuracy can be improved.

  (4) More preferably, the biological movement measuring device further includes a limiting unit for limiting the magnitude of the driving current.

  With such a configuration, it is possible to prevent an excessive current from flowing through the light emitter, so that the reliability of the biological motion measuring device can be improved.

  (5) A biological motion measuring apparatus according to another aspect of the present invention is a biological motion measuring apparatus for measuring movement of a living body based on a change in light transmitted through an optical fiber due to pressure applied to the optical fiber. A light receiving body for outputting a current or voltage corresponding to the intensity of light received from the optical fiber, and a predetermined frequency among frequency components of a light receiving signal based on the output current or output voltage of the light receiving body. In addition to attenuating the following components, an amplification unit for amplifying the light reception signal and a first analog / digital converter for converting the light reception signal that has passed through the amplification unit into a digital signal are provided.

  In this way, the light reception signal is amplified not by the digital signal processing unit but by the analog signal circuit in the preceding stage, so that the light reception signal at a minute level can be amplified and a more accurate result can be obtained in the analysis of the biological operation. it can. Also, by filtering the received light signal indicating the received light intensity, for example, low-frequency components such as drifts associated with long- and medium-term characteristic fluctuations of the light emitter, light receiver, and optical fiber are removed from the received light signal. Therefore, a more accurate result can be obtained in the analysis of the living body motion. Therefore, the movement of the living body can be accurately obtained by improving the measurement accuracy.

  (6) Preferably, the biological movement measuring device further includes a second analog / digital converter for converting the received light signal into a digital signal.

  With such a configuration, for example, in addition to respiration and heartbeat of the living body, it is possible to measure the movement of the living body that is removed by the filter, so that the function of the living body operation measuring apparatus can be improved.

  (7) Preferably, the living body motion measurement apparatus further includes a shift unit connected between the light receiver and the first analog / digital converter for shifting the direct current level of the light reception signal. .

  With such a configuration, it is possible to secure a dynamic range of the analog / digital converter and obtain a digital signal that accurately represents the output current or output voltage of the photoreceptor.

  (8) Preferably, the living body motion measuring device further extracts a high frequency component of the digital signal as a heartbeat component of the living body by performing digital filter processing and discrete Fourier transform processing on the digital signal, And the analysis part for extracting the low frequency component of the said digital signal as a respiration component of a biological body is provided.

  With such a configuration, it is possible to accurately measure the respiration and heartbeat of a living body using an appropriate analysis method.

  (9) Preferably, the living body motion measurement apparatus further includes an analysis unit for extracting a respiratory component and a heart rate component of the living body from the digital signal by performing analysis by wavelet transform using the digital signal. .

  With such a configuration, it is possible to accurately measure the respiration and heartbeat of a living body using an appropriate analysis method.

  (10) Preferably, the living body motion measurement apparatus further includes an abnormality detection unit for outputting an alarm signal when a state where the fluctuation range of the digital signal is less than a predetermined threshold continues for a predetermined time or more.

  With such a configuration, it is possible to detect an abnormality of the living body, notify the occurrence of the abnormality, or use the occurrence of the abnormality for signal processing, so that the function of the living body motion measuring apparatus can be improved.

  (11) A living body motion measuring apparatus according to another aspect of the present invention is a living body motion measuring apparatus for measuring a movement of a living body based on a change in pressure applied to a sensing unit to be brought into contact with the living body. And a plurality of signal generation units for generating digital signals indicating changes in pressure applied to the corresponding sensing units, and independent using the digital signals generated by the signal generation units. An analysis unit for extracting a respiratory component and a heartbeat component of the living body from the digital signal by performing component analysis;

  With such a configuration, it is possible to accurately obtain the respiration and heartbeat of the living body using an appropriate analysis method. Therefore, the movement of the living body can be accurately measured by improving the analysis accuracy.

  (12) Preferably, the biological motion measurement device includes three or more signal generation units, and the analysis unit performs independent component analysis using the digital signals generated by the signal generation units. Then, the respiratory component, heart rate component and other body motion components of the living body are extracted from the digital signal.

  With such a configuration, in addition to respiration and heartbeat of the living body, other actions of the living body can be accurately measured using an appropriate analysis method.

  (13) Preferably, the living body motion measuring device measures the movement of the living body based on a change in light transmitted through the optical fiber due to pressure applied to the optical fiber, and the signal generation unit is connected to the optical fiber. A light receiving body for outputting a current or voltage corresponding to the intensity of received light, and an analog / digital converter for converting a light receiving signal based on the output current or output voltage of the light receiving body into a digital signal.

  With such a configuration, in particular, in a contact-type pressure sensor using an optical fiber, it is possible to accurately measure the respiration and heartbeat of a living body using an appropriate analysis method.

  (14) A biological motion measurement method according to a certain aspect of the present invention is a biological motion measurement in a biological motion measurement device that measures movement of a biological body based on a change in light transmitted through an optical fiber due to pressure applied to the optical fiber. A method comprising: receiving a setting of light emission intensity of a light emitter for outputting light to the optical fiber; and driving the light emitter according to the received set value.

  As described above, the configuration in which the light emission intensity of the light emitter can be set and changed makes it possible to adjust the light emission signal according to variations in the light emitter, the light receiver, the optical fiber, and the like. That is, since the intensity of the received light signal in each living body motion measurement device can be maximized and uniform, the quality of the transmitted light can be improved and the measurement accuracy can be improved. Therefore, the movement of the living body can be accurately obtained by improving the measurement accuracy.

  (15) According to another aspect of the present invention, there is provided a biological motion measurement method in which a biological motion is measured in a biological motion measurement apparatus that measures movement of a biological body based on a change in light transmitted through an optical fiber due to pressure applied to the optical fiber. An operation measurement method comprising: outputting a current or voltage corresponding to the intensity of light received from the optical fiber; and a component having a frequency equal to or lower than a predetermined frequency among frequency components of a received light signal based on the output current or voltage. Attenuating and amplifying the received light signal; and attenuating components below the predetermined frequency and converting the amplified received light signal into a digital signal.

  In this way, the light reception signal is amplified not by the digital signal processing unit but by the analog signal circuit in the preceding stage, so that the light reception signal at a minute level can be amplified and a more accurate result can be obtained in the analysis of the biological operation. it can. Also, by filtering the received light signal indicating the received light intensity, for example, low-frequency components such as drifts associated with long- and medium-term characteristic fluctuations of the light emitter, light receiver, and optical fiber are removed from the received light signal. Therefore, a more accurate result can be obtained in the analysis of the living body motion. Therefore, the movement of the living body can be accurately obtained by improving the measurement accuracy.

  (16) A living body motion measuring method according to another aspect of the present invention is a living body motion measuring method in a living body motion measuring device for measuring a motion of a living body based on a change in pressure applied to a sensing unit to be brought into contact with the living body. Each of generating a digital signal indicating a change in pressure applied to the plurality of sensing units, and performing an independent component analysis using each of the generated digital signals, thereby generating a respiratory component of the living body and Extracting a heart rate component.

  With such a configuration, it is possible to accurately obtain the respiration and heartbeat of the living body using an appropriate analysis method. Therefore, the movement of the living body can be accurately measured by improving the analysis accuracy.

  According to the present invention, the movement of a living body can be accurately obtained by improving the measurement accuracy or the analysis accuracy.

It is a figure which shows the usage example of the biological movement measuring device which concerns on embodiment of this invention. It is a figure which shows the structure of the biological movement measuring device which concerns on embodiment of this invention. It is a figure which shows an example of the decomposition | disassembly structure of the optical fiber sheet which concerns on embodiment of this invention. It is a figure which shows an example of the cross-section of the optical fiber sheet which concerns on embodiment of this invention. It is a figure which shows the structure of the biological movement measuring device which concerns on embodiment of this invention in detail. It is a figure which shows the input waveform of the light reception voltage Vpd1 in the amplification part of the light reception part which concerns on embodiment of this invention. It is a figure which shows the output waveform of the light reception voltage Vpd2 in the amplification part of the light reception part which concerns on embodiment of this invention. It is a figure which shows the input waveform in the analysis using ICA by the biological motion measuring device which concerns on embodiment of this invention. It is a figure which shows the output waveform in the analysis using ICA by the biological motion measuring device which concerns on embodiment of this invention. It is a figure which shows the analysis result of the respiration of the biological body using the digital filter process and discrete Fourier transform process by the biological body motion measuring device which concerns on embodiment of this invention. It is a figure which shows the analysis result of the heartbeat of the biological body using the digital filter process and discrete Fourier transform process by the biological body motion measuring device which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the biological body operation | movement measuring method which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the biological body operation | movement measuring method which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the biological body operation | movement measuring method which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Configuration and basic operation]
FIG. 1 is a diagram illustrating a usage example of the biological motion measurement device according to the embodiment of the present invention.

  With reference to FIG. 1, the living body motion measuring apparatus 101 measures the movement of a living body such as a human based on a change in light transmitted through the optical fiber 3 due to pressure applied to the optical fiber 3.

  More specifically, the optical fibers 3 meander in the optical fiber sheet 2, and an optical transmission path that reciprocates between the living body motion measuring device 101 and the optical fiber sheet 2 is formed via the optical fiber sheet 2.

  The optical fiber sheet 2 is disposed on the bed 1, for example. The biological movement measuring device 101 outputs light to the optical fiber 3 and measures the transmitted light of the optical fiber 3 via the optical fiber sheet 2. Based on the measurement result, the biological motion measurement apparatus 101 measures the movement of the subject in a state where the subject is lying on the bed 1 and displays the measurement result on the display 112, for example.

  The living body motion measuring device 101 and the optical fiber sheet 2 constitute a living body motion measuring system 201.

  FIG. 2 is a diagram showing a configuration of the biological motion measuring apparatus according to the embodiment of the present invention.

  With reference to FIG. 2, the biological movement measuring device 101 includes a light emitting unit 11, a light receiving unit 13, and an analyzing unit 14.

  The light emitting unit 11 outputs light to the optical fiber 3. The light receiving unit 13 receives light via the optical fiber 3 and the optical fiber sheet 2, generates a digital signal indicating the amount of received light, for example, and outputs the digital signal to the analyzing unit 14.

  The analysis unit 14 analyzes the digital signal received from the light receiving unit 13, for example, measures the respiration, heartbeat and other actions of the subject on the optical fiber sheet 2, and outputs the measurement result to the presentation unit 15. .

  The presentation unit 15 is, for example, a display, and presents the measurement result received from the analysis unit 14 to the user.

  The analysis unit 14 may be configured to output an alarm signal when a state where the fluctuation range of the digital signal of the light reception signal is less than a predetermined threshold continues for a predetermined time or longer. In this case, for example, the presentation unit 15 receives a warning signal from the analysis unit 14 and displays a warning.

  FIG. 3 is a diagram showing an example of an exploded structure of the optical fiber sheet according to the embodiment of the present invention. FIG. 4 is a diagram showing an example of a cross-sectional structure of the optical fiber sheet according to the embodiment of the present invention.

  With reference to FIG. 3 and FIG. 4, the optical fiber sheet 2 includes an optical fiber 3 and a planar state 80. The optical fiber 3 is, for example, a quartz optical fiber or a plastic optical fiber. The planar state 80 supports the optical fiber 3. The optical fiber sheet 2 includes a sponge sheet 81, a cloth cover 83, and a mesh structure 84 including the optical fiber 3.

  The sponge sheet 81 is a breathable sheet having a large number of holes. In the mesh structure 84, the optical fiber 3 is knitted into the net cloth 82. The cloth cover 83 is a black cover and has a light shielding property. A mesh structure 84 is sandwiched between the sponge sheet 81 and the cloth cover 83. The optical fiber sheet 2 is produced by sewing the sponge sheet 81 and the peripheral edge of the cloth cover 83 together. The optical fibers 3 are arranged in a single stroke with six rows of arrangement portions parallel to the short sides of the optical fiber sheet 2.

  FIG. 5 is a diagram showing in detail the configuration of the biological movement measuring apparatus according to the embodiment of the present invention.

  Referring to FIG. 5, in living body motion measuring apparatus 101, light emitting unit 11 includes a light emitter 21, a drive unit 22, a setting unit 23, and a limiting unit 36. The light receiver 13 includes a light receiver 24, operational amplifiers 25, 28, and 32, a resistor 26, digital / analog converters (DACs) 30, 31, and 34, analog / digital converters (ADCs) 29 and 33, And an amplification unit 27. The amplifying unit 27 includes a filter 41 and an operational amplifier 42.

  In the light emitting unit 11, the light emitter 21 is, for example, an LED or an incandescent body, and outputs light to the optical fiber 3.

  The drive unit 22 drives the light emitter 21 by supplying, for example, a current to the light emitter 21. For example, the drive unit 22 supplies a direct current as a drive current to the light emitter 21.

  The setting unit 23 sets the light emission intensity of the light emitter 21. The drive unit 22 drives the light emitter 21 according to the setting value set by the setting unit 23. Here, the setting value of the light emission intensity of the light emitter 21 in the setting unit 23 can be changed. Specifically, for example, the setting unit 23 includes a digital / analog converter, and the user can set an input digital value of the digital / analog converter. Further, this set value is a value slightly smaller than the maximum allowable light emission amount of the light emitter 21, for example.

  The limiting unit 36 limits the magnitude of the driving current supplied from the driving unit 22 to the light emitter 21. Limiting unit 36 is a limiter circuit including a diode, for example. The limiting unit 36 may be a digital circuit that limits the setting value of the setting unit 23.

  In the light receiving unit 13, the light receiver 24 is a photodiode, for example, and outputs a current corresponding to the intensity of light received from the optical fiber 3. Note that the light receiver 24 may output a voltage corresponding to the intensity of light received from the optical fiber 3.

  The operational amplifier 25 has a resistor 26 connected between the input and output, converts the output current of the photoreceptor 24 into a received light voltage Vpd1, and outputs it as a received light signal. When the resistance value of the resistor 26 is R and the output current of the light receiver 24 is i, the light reception voltage Vpd1 is expressed by i × R.

  The digital / analog converter 34 outputs an analog voltage based on the input digital value to the operational amplifier 32. The operational amplifier 32 shifts the direct current level of the received light voltage Vpd 1 received from the operational amplifier 25 based on the analog voltage received from the digital / analog converter 34 and outputs it to the analog / digital converter 33. By changing the digital value applied to the digital / analog converter 34, the offset of the light reception voltage Vpd1 can be adjusted and the dynamic range of the analog / digital converter 33 can be ensured.

  The analog / digital converter 33 converts the received light voltage Vpd1 received from the operational amplifier 32 into a digital signal and outputs the digital signal to the CPU 35, which is an example of the analysis unit 14.

  The amplifying unit 27 is, for example, an AC amplifier, and converts the light reception voltage Vpd1 into a light reception voltage Vpd2 in which the direct current component is attenuated and the signal component indicating the movement of the living body is amplified. In the amplifying unit 27, the filter 41 attenuates a component of the received light voltage Vpd <b> 1 received from the operational amplifier 25 that is equal to or lower than a predetermined frequency including a direct current component. The filter 41 may be configured to attenuate a low frequency component including a direct current component, and is, for example, a band pass filter or a high pass filter.

  The digital / analog converter 30 outputs an analog voltage based on the input digital value to the operational amplifier 42. The operational amplifier 42 shifts the direct current level of the received light voltage Vpd 1 that has passed through the filter 41 based on the analog voltage received from the digital / analog converter 30. The operational amplifier 42 amplifies the received light voltage Vpd1 that has passed through the filter 41. Note that the arrangement order of the filter 41 and the operational amplifier 42 may be reversed.

  FIG. 6 is a diagram illustrating an input waveform of the light reception voltage Vpd1 in the amplification unit of the light reception unit according to the embodiment of the present invention.

  Referring to FIG. 6, light reception voltage Vpd <b> 1 has a substantially constant DC level in a state where no subject exists on optical fiber sheet 2. Then, when the subject lies on the optical fiber sheet 2, excessive loss occurs in the optical transmission in the optical fiber sheet 2 due to the pressure on the optical fiber sheet 2 by the subject, and the level of the light reception voltage Vpd1 is lowered. Thereafter, the light reception voltage Vpd1 varies at a minute level due to the body movement of the subject. And if a subject leaves | separates from the optical fiber sheet 2, the light reception voltage Vpd1 will return to the said direct current | flow level.

  FIG. 7 is a diagram showing an output waveform of the light reception voltage Vpd2 in the amplification section of the light reception section according to the embodiment of the present invention.

  Referring to FIG. 7, in the amplifying unit 27, the low frequency component of the light reception voltage Vpd1 is attenuated by the filter 41 and amplified by the operational amplifier 42 to be converted into the light reception voltage Vpd2. The first peak portion and the last peak portion in the waveform shown in FIG. 7 are undershoot and overshoot, respectively.

  By obtaining the light reception voltage Vpd2 having such a waveform by the amplifying unit 27, even when the light reception signal fluctuates at a minute level, a more accurate result can be obtained in the analysis of the biological operation.

  Referring to FIG. 5 again, the digital / analog converter 31 outputs an analog voltage based on the input digital value to the operational amplifier 28. Based on the analog voltage received from the digital / analog converter 31, the operational amplifier 28 shifts the direct current level of the received light voltage Vpd 2 received from the amplification unit 27 and outputs it to the analog / digital converter 29.

  By changing the digital value applied to the digital / analog converters 30 and 31, offset adjustment of the light reception voltages Vpd1 and Vpd2 can be performed, and the dynamic range of the analog / digital converter 29 can be ensured. When the offset adjustment is sufficient for either one of the operational amplifiers 42 and 28, the other offset adjustment function may not be installed.

  The analog / digital converter 29 converts the received light voltage Vpd2 received from the operational amplifier 28 into a digital signal and outputs the digital signal to the CPU 35, which is an example of the analysis unit 14.

  The CPU 35 measures, for example, the respiration and heartbeat of the subject on the optical fiber sheet 2 by analyzing the digital signal received from the analog / digital converter 29.

  Further, the CPU 35 measures body movements other than breathing and heartbeat of the subject on the optical fiber sheet 2 based on the digital signal received from the analog / digital converter 33, for example.

  Note that some or all of the drive unit 22, the setting unit 23, and the limiting unit 36 in the light emitting unit 11 may be realized by the CPU 35.

  The amplification factors of the operational amplifiers 32 and 28 may be 1 or may be larger than 1. For example, when the amplification factor of the operational amplifier 25 is sufficient, the amplification factors of the operational amplifiers 32 and 28 are set to 1.

  Further, the light emitting unit 11 is not limited to a configuration that outputs light to the optical fiber 3 continuously, but may be a configuration that outputs light to the optical fiber 3 intermittently. In this case, the drive unit 22 supplies the light emitter 21 with a pulsed current as a drive current.

  In this case, the light receiving unit 13 includes, for example, a sample / hold circuit for holding the peak value of the output current of the light receiving body 24, generates a digital signal indicating a waveform connecting the peak values at each timing, and analyzes the analyzing unit 14. Output to.

  As described above, the configuration using the pulsed current allows the instantaneous maximum value of the light emission amount of the light emitter 21 to be larger than that when light is continuously output.

  Next, a method for analyzing a received light signal by the biological motion measuring apparatus according to the embodiment of the present invention will be described.

[Analysis method using ICA]
The analysis unit 14 performs independent component analysis using the digital signals generated by the plurality of light receiving units 13, thereby extracting a respiratory component and a heart rate component of the living body from the digital signal.

  FIG. 8 is a diagram showing an input waveform in an analysis using ICA by the biological motion measurement apparatus according to the embodiment of the present invention. In FIG. 8, the horizontal axis represents time, specifically, the number of samples under a constant sampling interval, and the vertical axis represents the level of the light reception voltage Vpd2, that is, the amount of light received by the light receiving unit 13.

  Referring to FIG. 8, in the analysis method using ICA, for example, two sets of optical fiber sheet 2 and light receiving unit 13 are prepared, two optical fiber sheets 2 are overlapped, and these optical fiber sheets 2 are overlaid. Measure the movement of the subject. In addition, it is possible to arrange separate small optical fiber sheets 2 on the chest and abdomen of the subject and to measure the movement of the subject. The component derived from the heartbeat and the respiratory origin of the measurement signal obtained from each optical fiber sheet 2 This is useful because the ratio of the components is greatly different. Specifically, it is estimated that the ratio of the respiratory-derived component is high in the sensing unit arranged in the abdomen, and the ratio of the heartbeat-derived component is high in the sensing unit arranged in the chest.

  Here, it is assumed that measurement waveforms 1 and 2 as shown in FIG.

  FIG. 9 is a diagram showing an output waveform in the analysis using the ICA by the biological motion measurement device according to the embodiment of the present invention.

  Referring to FIG. 9, analysis unit 14 performs ICA using measurement waveforms 1 and 2 to generate post-ICA waveforms 1 and 2 as shown in FIG. 9. The post-ICA waveform 1 is a high-frequency component of the light reception voltage Vpd2 and is derived from the heartbeat of the subject. The post-ICA waveform 2 is a low-frequency component of the light reception voltage Vpd2 and is derived from the subject's breathing.

  In addition to the respiration and heartbeat of the living body, when measuring other body movements of the living body, three or more sets may be prepared.

  That is, the analysis unit 14 performs independent component analysis using the digital signals generated by the three or more light receiving units 13, thereby extracting a respiratory component, a heart rate component, and other body motion components of the living body from the digital signal. To do.

  In addition, the analysis method using ICA is not limited to the biological motion measurement device using the optical fiber as described above, and other contact pressure sensors, that is, the movement of the subject in a state where the sensing unit is in contact with the subject. It can be effectively applied to a sensor to be measured. As this contact-type pressure sensor, for example, a sensor using a piezoelectric film as a sensing unit, a sensor using a tube filled with liquid as a sensing unit, and the like can be considered.

  In this case, in the biological motion measurement device, the plurality of signal generation units are provided corresponding to the sensing units, and generate digital signals indicating changes in pressure applied to the corresponding sensing units.

  And the analysis part 14 extracts a respiratory component, a heart rate component, etc. of a biological body from the said digital signal by performing an independent component analysis using the digital signal produced | generated by each signal production | generation part.

[Analysis method using digital filter processing and discrete Fourier transform processing]
The analysis unit 14 performs a filtering process and a discrete Fourier transform process on the digital signal of the received light signal, thereby extracting a high frequency component of the digital signal as a heartbeat component of the living body, and a low frequency component of the digital signal. Extracted as a respiratory component of the living body.

  In the analysis method using the digital filter process and the discrete Fourier transform process, one set of the optical fiber sheet 2 and the light receiving unit 13 may be prepared.

  FIG. 10 is a diagram showing a result of analysis of respiration of a living body using digital filter processing and discrete Fourier transform processing by the living body motion measuring apparatus according to the embodiment of the present invention. In FIG. 10, the upper waveform is a waveform obtained by the analysis processing of the biological motion measurement device 101, and the lower waveform is a waveform obtained by a normal respiratory measurement device.

  Referring to FIG. 10, the analysis unit 14 obtains a waveform c1 representing the respiration of the subject on the optical fiber sheet 2 by extracting a low frequency component of the waveform a1 indicated by the digital signal received from the light receiving unit 13. . The waveform b1 and the waveform d1 are waveforms obtained by performing discrete Fourier transform processing on the waveform a1 and the waveform c1. For example, the analysis unit 14 obtains the number of beats, that is, the frequency of the peak portion in the waveform d1.

  Moreover, the waveform c2 is obtained by extracting the low frequency component of the waveform a2 obtained by the normal respiratory measurement apparatus. The waveform b2 and the waveform d2 are waveforms obtained by performing a discrete Fourier transform process on the waveform a2 and the waveform c2.

  As a result of measuring the subject using both the biological motion measurement device 101 and the normal respiration measurement device, the number of beats (frequency) of the peak portion in the waveform d1 shown in FIG. 10 is 15.68 bpm (about 0.8. 261 Hz), and the number of pulsations (frequency) of the peak portion in the waveform d2 was 15.82 bpm (about 0.264 Hz). From this result, it can be seen that the living body respiration can be accurately measured using the living body motion measuring apparatus 101. Here, “bpm” is the number of beats per minute.

  FIG. 11 is a diagram showing the analysis result of the heartbeat of the living body using the digital filter processing and the discrete Fourier transform processing by the living body motion measuring apparatus according to the embodiment of the present invention. In FIG. 11, the upper waveform is a waveform obtained by the analysis processing of the biological motion measuring device 101, and the lower waveform is a waveform obtained by a normal heartbeat measuring device.

  With reference to FIG. 11, the analysis unit 14 obtains a waveform c3 representing the heartbeat of the subject on the optical fiber sheet 2 by extracting a high-frequency component of the waveform a3 indicated by the digital signal received from the light receiving unit 13. The waveform b3 and the waveform d3 are waveforms obtained by performing discrete Fourier transform processing on the waveform a3 and the waveform c3. For example, the analysis unit 14 obtains the number of beats, that is, the frequency of the peak portion in the waveform d3.

  Moreover, the waveform c4 is obtained by extracting the low frequency component of the waveform a4 obtained by the normal heartbeat measuring device. The waveform b4 and the waveform d4 are waveforms obtained by performing a discrete Fourier transform process on the waveform a4 and the waveform c4.

  As a result of measuring the subject using both the biological motion measuring device 101 and the normal heart rate measuring device, the number of beats (frequency) of the peak portion in the waveform d3 shown in FIG. 11 is 81.32 bpm (about 1.2. 355 Hz), and the frequency of the peak portion in the waveform d4 was 81.69 bpm (about 1.362 Hz). From this result, it can be seen that the living body heart rate of the living body can be accurately measured using the living body motion measuring apparatus 101.

  The living body motion measuring apparatus 101 is not limited to the analysis method as described above, and the analysis unit 14 performs analysis by wavelet transform using the digital signal of the light reception signal, so that the respiratory component of the living body and The structure which extracts a heartbeat component may be sufficient. As an example of the analysis method using the wavelet transform, for example, there is a calculation method described in paragraphs [0032] to [0051] of Japanese Patent No. 486047.

  In addition, the biological motion measuring apparatus 101 outputs the analog signal from the analog / digital converter 33 in place of or in addition to the digital signal output from the analog / digital converter 29 using each of the analysis methods as described above. The digital signal may be analyzed to measure the respiration and heartbeat of the living body.

  FIG. 12 is a flowchart showing a procedure of the biological motion measurement method according to the embodiment of the present invention.

  With reference to FIG. 12, first, the biological body motion measurement device 101 receives the setting of the light emission intensity of the light emitter 21 (step S1). For example, the CPU 35 controls the setting unit 23 immediately before the biological motion measurement to change the light emission intensity while measuring the light reception signal, obtain an appropriate light emission amount, and set this to set the light emission intensity of the light emitter 21. Value. For example, the CPU 35 sets the light emission intensity at which the light emission amount is slightly smaller than the upper limit of the normal measurement range of the received light amount as the set value of the light emitter 21.

  Next, the biological movement measuring device 101 supplies a drive current to the light emitter 21 according to the set value (step S2), and outputs light to the optical fiber 3 (step S3).

  FIG. 13 is a flowchart showing a procedure of the biological motion measurement method according to the embodiment of the present invention.

  With reference to FIG. 13, first, the biological motion measurement device 101 receives the transmission light of the optical fiber 3 (step S <b> 11).

  Next, the biological movement measuring device 101 generates a light reception signal indicating the amount of received light (step S12).

  Next, the biological movement measuring device 101 attenuates components having a frequency equal to or lower than a predetermined frequency including the direct current component of the received light signal (step S13).

  Next, the living body motion measuring apparatus 101 amplifies the received light signal having the attenuated DC component (step S14). Note that the order of the filtering process in step S13 and the amplification process in step S14 may be reversed.

  Next, the biological movement measuring device 101 converts the amplified received light signal into a digital signal (step S15).

  Next, the biological movement measuring device 101 analyzes the converted digital signal using various methods, and obtains the movement of the subject on the optical fiber sheet 2 (step S16).

  Next, the biological motion measuring device 101 displays the measurement result of the subject on the optical fiber sheet 2 on a display or the like (step S17).

  FIG. 14 is a flowchart showing the procedure of the biological motion measurement method according to the embodiment of the present invention.

  Referring to FIG. 14, first, two or more sensing units and signal generation units, for example, two or more sets of optical fiber 3, optical fiber sheet 2, and light receiving unit 13 are prepared. A digital signal indicating the pressure applied to the sensing unit is generated (step S21).

  Next, the living body motion measuring device 101 performs ICA using each generated digital signal, thereby obtaining respiration, heartbeat, and the like of the living body in contact with the sensing unit (step S22).

  The living body motion measuring apparatus 101 is small and quiet, and can measure, for example, by laying the optical fiber sheet 2 under a sheet covering a futon and laying the subject. That is, the movement of the living body can be measured with a simple operation without attaching anything to the subject's body. By using the living body motion measuring apparatus 101, it is possible to observe the respiration of the subject in a state close to a normal living environment.

  Here, in the optical fiber sheet measuring system described in Patent Document 1, the light source for the optical fiber sensor is composed of a He-Ne laser, an optical chopper, and a condenser lens, and the light receiving system is a photodiode, lock-in It consists of an amplifier, a data logger, and a PC. For this reason, the transmission-side device and the reception-side device are distributed and are not in a form that can be easily used in the home. In addition, when the transmission side device and the reception side device are housed in one housing, the device is considerably large.

  In addition, the measurement system described in Patent Document 2 is configured by using a USB type LED and a notebook PC as a light source, and the light receiving system is configured by using an optical power meter and a notebook PC that is also used as a light source. ing. For this reason, it has not arrived at the form simplified enough for using at home. Furthermore, in a small optical multimeter, the sampling interval of received light data is generally 0.1 seconds, that is, 10 Hz, and body movements that depend on a heart rate signal of 0.8 Hz to 3.3 Hz (50 bpm to 200 bpm) are detected. Insufficient performance.

  On the other hand, in the biological motion measuring device 101, not only a long-period body motion of about 0.2 Hz to 0.8 Hz (10 bpm to 50 bpm) due to respiration but also a short-cycle body motion due to a heartbeat or the like. It can measure with high accuracy. In addition, the biological motion measurement device 101 can be easily configured as a small and light device, has high measurement accuracy, and high adaptability to variations in the optical fiber sheet used. Moreover, since it is mainly composed of electronic components, cost reduction is easy.

  By the way, in the sensor using the optical fiber, if the quality of the light transmitted through the optical fiber is deteriorated, the measurement accuracy is lowered, and it is difficult to accurately measure the movement of the living body. Required. In particular, higher measurement accuracy is required when attempting to measure not only breathing but also heartbeats that have a shorter cycle than breathing.

  On the other hand, in the biological movement measuring device according to the embodiment of the present invention, the light emitter 21 outputs light to the optical fiber 3. The setting unit 23 sets the light emission intensity of the light emitter 21. And the setting value of the light emission intensity in the setting part 23 is changeable.

  As described above, the configuration in which the light emission intensity of the light emitter 21 can be set and changed makes it possible to adjust the light emission signal in accordance with variations of the light emitter 21 and the optical fiber sheet 2 and the like. That is, since the intensity of the received light signal in each living body motion measuring device 101 can be maximized and uniformized, the quality of the transmitted light can be improved and the measurement accuracy can be improved.

  Therefore, in the living body motion measuring apparatus according to the embodiment of the present invention, the movement of the living body can be accurately obtained by improving the measurement accuracy.

  In the living body motion measurement apparatus according to the embodiment of the present invention, the drive unit 22 supplies a direct current as a drive current to the light emitter 21.

  With such a configuration, it becomes easy to perform filter processing on the received light signal indicating the intensity of light transmitted through the optical fiber 3, that is, the amount of received light. For example, from the received light signal to the light emitter, the light receiver, and the optical fiber. Thus, it is possible to remove low-frequency components such as drift associated with long- and medium-term characteristic fluctuations such as, and more accurate results can be obtained in the analysis of biological movements.

  In the living body motion measurement apparatus according to the embodiment of the present invention, the drive unit 22 supplies a pulsed current to the light emitter 21 as a drive current.

  As described above, the configuration using the pulse-like current allows the instantaneous maximum value of the light emission amount of the light emitter 21 to be larger than that in the case of continuously outputting light, and the quality of the transmitted light. And the measurement accuracy can be improved.

  In the living body motion measurement apparatus according to the embodiment of the present invention, the limiting unit 36 limits the magnitude of the drive current.

  With such a configuration, it is possible to prevent an excessive current from flowing through the light emitter 21, so that the reliability of the biological motion measuring apparatus 101 can be improved.

  In the living body motion measurement apparatus according to the embodiment of the present invention, the light receiver 24 outputs a current or a voltage corresponding to the intensity of light received from the optical fiber 3. The amplifying unit 27 attenuates a component equal to or lower than a predetermined frequency among the frequency components of the received light signal based on the output current or output voltage of the photoreceptor 24 and amplifies the received light signal. The analog / digital converter 29 converts the received light signal that has passed through the amplifying unit 27 into a digital signal.

  In this way, the light reception signal is amplified not by the digital signal processing unit but by the analog signal circuit in the preceding stage, so that the light reception signal at a minute level can be amplified and a more accurate result can be obtained in the analysis of the biological operation. it can. Also, by filtering the received light signal indicating the received light intensity, for example, low-frequency components such as drifts associated with long- and medium-term characteristic fluctuations of the light emitter, light receiver, and optical fiber are removed from the received light signal. Therefore, a more accurate result can be obtained in the analysis of the living body motion.

  Therefore, in the living body motion measuring apparatus according to the embodiment of the present invention, the movement of the living body can be accurately obtained by improving the measurement accuracy.

  In the living body motion measurement apparatus according to the embodiment of the present invention, the analog / digital converter 33 converts the received light signal into a digital signal.

  With such a configuration, for example, in addition to the respiration and heartbeat of the living body, it is possible to measure the movement of the living body that is removed by the filter, so that the function of the living body movement measuring apparatus 101 can be improved.

  In the living body motion measurement apparatus according to the embodiment of the present invention, the operational amplifier 28 or 42 is connected between the light receiver 24 and the analog / digital converter 29 to shift the direct current level of the light reception signal.

  With such a configuration, the dynamic range of the analog / digital converter can be secured, and a digital signal that accurately represents the output current or output voltage of the photoreceptor 24 can be obtained.

  Further, in the biological motion measurement device according to the embodiment of the present invention, the analysis unit 14 performs digital filter processing and discrete Fourier transform processing on the digital signal of the received light signal, thereby obtaining a high-frequency component of the digital signal. It extracts as a heartbeat component of the living body and extracts a low frequency component of the digital signal as a respiratory component of the living body.

  With such a configuration, it is possible to accurately measure the respiration and heartbeat of a living body using an appropriate analysis method.

  Further, in the living body motion measuring apparatus according to the embodiment of the present invention, the analysis unit 14 performs analysis by wavelet transform using the digital signal of the received light signal, thereby obtaining the respiratory component and heart rate component of the living body from the digital signal. Extract.

  With such a configuration, it is possible to accurately measure the respiration and heartbeat of a living body using an appropriate analysis method.

  Moreover, in the biological motion measurement device according to the embodiment of the present invention, the analysis unit 14 outputs an alarm signal when a state where the fluctuation range of the digital signal of the light reception signal is less than a predetermined threshold continues for a predetermined time or longer. .

  With such a configuration, it is possible to detect an abnormality of the living body, notify the occurrence of the abnormality, or use the occurrence of the abnormality for signal processing. Therefore, it is possible to improve the function of the living body motion measuring apparatus 101.

  In addition, in a sensor for detecting the movement of a living body, such as a sensor using an optical fiber, as an example of a movement of a living body, when it is attempted to measure not only breathing but also a heartbeat with a shorter cycle than breathing, A technique for appropriately analyzing signals is desired.

  On the other hand, in the biological motion measurement device according to the embodiment of the present invention, the plurality of signal generation units are provided corresponding to the sensing units that are brought into contact with the living body, and show changes in pressure applied to the corresponding sensing units. Generate a digital signal. And the analysis part 14 extracts a respiratory component and a heart rate component of a biological body from the said digital signal by performing an independent component analysis using the digital signal produced | generated by each signal production | generation part.

  With such a configuration, it is possible to accurately obtain the respiration and heartbeat of the living body using an appropriate analysis method. Therefore, in the living body motion measuring apparatus according to the embodiment of the present invention, the movement of the living body can be accurately measured by improving the analysis accuracy.

  Moreover, in the biological motion measurement device according to the embodiment of the present invention, the biological motion measurement device includes three or more signal generation units. And the analysis part 14 extracts a respiratory component, a heart rate component, and another body motion component of a biological body from the said digital signal by performing an independent component analysis using the digital signal produced | generated by each signal production | generation part.

  With such a configuration, in addition to respiration and heartbeat of the living body, other actions of the living body can be accurately measured using an appropriate analysis method.

  Moreover, in the biological motion measuring device according to the embodiment of the present invention, the analysis unit 14 performs independent component analysis using the digital signals generated by the plurality of light receiving units 13, thereby respiration of the living body from the digital signals. Extract components and heart rate components.

  With such a configuration, in particular, in a contact-type pressure sensor using an optical fiber, it is possible to accurately measure the respiration and heartbeat of a living body using an appropriate analysis method.

  In addition, even if the living body motion measuring device 101 is configured to include any one of the light emitting unit 11, the light receiving unit 13, and the analyzing unit 14, by improving the measurement accuracy or the analysis accuracy, It is possible to achieve the object of the present invention of accurately obtaining movement.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Bed 2 Optical fiber sheet 3 Optical fiber 11 Light emission part 12 Display 13 Light reception part 14 Analysis part 15 Presentation part 21 Light emission body 22 Drive part 23 Setting part 24 Light reception body 25,28,32,42 Operational amplifier 26 Resistance 27 Amplification part 29, 33 Analog / Digital Converter 30, 31, 34 Digital / Analog Converter 36 Restriction Unit 41 Filter 80 Planar State 81 Sponge Sheet 82 Net Cloth 83 Cloth Cover 84 Mesh Structure 101 Biological Motion Measuring Device 201 Biological Motion Measuring System

Claims (16)

A biological motion measuring device for measuring movement of a living body based on a change in light transmitted through an optical fiber due to pressure applied to the optical fiber,
A light emitter for outputting light to the optical fiber;
A setting unit for setting the light emission intensity of the light emitter,
The biological movement measuring device, wherein the set value of the emission intensity in the setting unit is changeable. The biological movement measuring device further includes:
A drive unit for driving the light emitter according to the set value;
The living body motion measuring apparatus according to claim 1, wherein the driving unit supplies a direct current as a driving current to the light emitter. The biological movement measuring device further includes:
A drive unit for driving the light emitter according to the set value;
The biological movement measuring device according to claim 1, wherein the driving unit supplies a pulsed current as a driving current to the light emitter. The biological movement measuring device further includes:
The biological movement measuring device according to claim 2 or 3, further comprising a limiting unit for limiting the magnitude of the driving current. A biological motion measuring device for measuring movement of a living body based on a change in light transmitted through an optical fiber due to pressure applied to the optical fiber,
A photoreceptor for outputting a current or voltage according to the intensity of light received from the optical fiber;
Among the frequency components of the received light signal based on the output current or output voltage of the photoreceptor, an amplifying unit for amplifying the received light signal while attenuating a component below a predetermined frequency;
A biological movement measuring device comprising: a first analog / digital converter for converting the received light signal that has passed through the amplifying unit into a digital signal. The biological movement measuring device further includes:
The biological movement measuring device according to claim 5, further comprising a second analog / digital converter for converting the received light signal into a digital signal. The biological movement measuring device further includes:
The biological movement measuring device according to claim 5, further comprising a shift unit that is connected between the light receiver and the first analog / digital converter and shifts a direct current level of the light reception signal. . The biological movement measuring device further includes:
By performing digital filter processing and discrete Fourier transform processing on the digital signal, a high frequency component of the digital signal is extracted as a heartbeat component of the living body, and a low frequency component of the digital signal is extracted as a breathing component of the living body. The biological movement measuring device according to any one of claims 5 to 7, further comprising an analysis unit for performing the operation. The biological movement measuring device further includes:
8. The apparatus according to claim 5, further comprising an analysis unit configured to extract a respiratory component and a heartbeat component of a living body from the digital signal by performing analysis by wavelet transform using the digital signal. Biological movement measuring device. The biological movement measuring device further includes:
10. The abnormality detection unit according to claim 5, further comprising an abnormality detection unit configured to output an alarm signal when a state where the fluctuation range of the digital signal is less than a predetermined threshold continues for a predetermined time or more. Biological motion measurement device. A biological motion measuring device for measuring movement of a living body based on a change in pressure applied to a sensing unit to be brought into contact with the living body,
A plurality of signal generation units provided corresponding to the sensing units, for generating a digital signal indicating a change in pressure applied to the corresponding sensing unit;
A biological movement measurement device comprising: an analysis unit for extracting a respiratory component and a heartbeat component of a living body from the digital signal by performing independent component analysis using the digital signal generated by each of the signal generation units. The biological movement measurement device includes three or more signal generation units,
The analysis unit extracts a respiratory component, a heartbeat component, and other body motion components of a living body from the digital signal by performing independent component analysis using the digital signals generated by the signal generation units. Item 12. The biological motion measurement device according to Item 11. The biological movement measuring device measures the movement of the living body based on the change of the light transmitted through the optical fiber due to the pressure applied to the optical fiber,
The signal generator is
A photoreceptor for outputting a current or voltage according to the intensity of light received from the optical fiber;
The biological movement measuring device according to claim 11 or 12, comprising an analog / digital converter for converting a received light signal based on an output current or an output voltage of the photoreceptor into a digital signal. A biological motion measuring method in a biological motion measuring device that measures the movement of a living body based on a change caused by pressure applied to the optical fiber of light transmitted through an optical fiber,
Receiving a setting of the light emission intensity of the light emitter for outputting light to the optical fiber;
And a step of driving the light emitter according to the received set value. A biological motion measuring method in a biological motion measuring device that measures the movement of a living body based on a change caused by pressure applied to the optical fiber of light transmitted through an optical fiber,
Outputting a current or voltage according to the intensity of light received from the optical fiber;
Among the frequency components of the received light signal based on the output current or voltage, attenuating a component below a predetermined frequency and amplifying the received light signal;
And a step of attenuating the component below the predetermined frequency and converting the received light signal subjected to amplification into a digital signal. A biological motion measuring method in a biological motion measuring device for measuring a movement of a living body based on a change in pressure applied to a sensing unit to be brought into contact with the living body,
Generating digital signals each indicating a change in pressure applied to the plurality of sensing units;
Extracting the respiratory component and the heartbeat component of the living body from the digital signal by performing independent component analysis using each of the generated digital signals.

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