JP2013183845A - Pulsation detector, electronic device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulsation detector, an electronic device and a program, capable of executing an appropriate body movement noise reducing process even if a pulsation component is included in a body movement detection signal.SOLUTION: A pulse detector 100 includes: a body movement noise reducing part 115 for executing a body movement noise reducing process to reduce body movement noise components included in a pulse wave detection signal from a pulse wave detection part 10 including a pulse wave sensor 11; and a determining part 114 for executing a determining process for a body movement detection signal used in the body movement noise reducing process. The determining part 114 decides whether or not a pulsation component is included in a contact pressure detection signal from a body movement detection part 20 having a contact pressure sensor 22, and executes a determining process for determining whether or not the contact pressure detection signal should be used as the body movement detection signal based on the result of decision. The body movement noise reducing part 115 executes a body movement noise reducing process based on the pulse wave detection signal and the contact pressure detection signal if it is determined that the contact pressure detection signal should be used as the body movement detection signal.

Description

  The present invention relates to a pulsation detection device, an electronic device, a program, and the like.

  Conventionally, electronic devices including a pulsation detecting device such as a pulse meter have been widely used. The pulsation detection device is a device for detecting pulsation derived from the heartbeat of the human body, for example, based on a signal from a pulse wave sensor attached to an arm, palm, finger, etc. It is an apparatus for detecting a signal to be detected.

  For example, a photoelectric sensor is used as the pulse wave sensor. In this case, a method of detecting reflected light or transmitted light of the light irradiated on the living body with the photoelectric sensor can be considered. Depending on the blood flow in the blood vessel, the amount of light absorbed and reflected by the living body differs, so the sensor information (pulse wave sensor signal) detected by the photoelectric sensor is a signal corresponding to the blood flow, etc. By analyzing the signal, it is possible to obtain information on the beat.

  However, various noises may be mixed in the pulse wave sensor signal. For example, outside light such as sunlight or indoor lighting may enter in addition to reflected light, and noise (body movement noise component) generated by the influence of body movement of the human body may be mixed. Therefore, when detecting a pulsation signal, the pulse wave sensor signal (pulse wave detection signal) is not used as it is, but body motion noise components included in the pulse wave sensor signal before the pulsation signal detection process, etc. In many cases, noise reduction processing is performed to reduce noise. For example, Patent Literature 1 and Patent Literature 2 disclose a technique for removing such body motion noise.

JP 2004-283228 A JP 2010-17602 A

  As described above, in the pulsation detecting device, it is assumed that various noises are mixed in the pulse wave sensor signal acquired from the pulse wave sensor (or the pulse wave detection signal acquired therefrom). Therefore, if noise reduction processing that reduces body movement noise components included in the pulse wave sensor signal is not performed, the detected pulsation information will be affected by noise, so the value of the pulsation information is attached May not accurately represent the person's actual beat. In this case, if the pulsation information is simply output, the user's judgment based on the pulsation information may be mistaken.

  In addition, when removing body motion noise, a body motion detection signal is obtained from a signal obtained from a pressure sensor, an acceleration sensor, etc., and this is treated as a body motion noise component. In some cases, noise may be mixed. When the body motion noise component is removed from the pulse wave sensor signal using the body motion detection signal including such noise, the detected pulsation information is also affected by the noise, and the pulsation information Similarly to the case where the body motion noise component is not removed, the value of may not accurately represent the actual beat of the wearer.

  Furthermore, when a body motion detection signal is obtained using a contact pressure sensor as disclosed in Patent Document 1, depending on the magnitude of the contact pressure between the contact pressure sensor and the living body (measurement site), body motion detection is performed. A pulsation component may be included in the signal (contact pressure detection signal). When performing body motion noise reduction processing using a body motion detection signal containing such a pulsation component as a body motion noise component, not only the actual body motion noise component but also the pulsation component that should be detected originally May be attenuated.

  According to some aspects of the present invention, there is provided a pulsation detection device, an electronic device, a program, and the like that can perform appropriate body motion noise reduction processing even when a pulsation component is included in the body motion detection signal. Can be provided.

  One aspect of the present invention is a body motion noise reduction unit that performs a body motion noise reduction process for reducing a body motion noise component included in a pulse wave detection signal from a pulse wave detection unit having a pulse wave sensor, and the body motion noise A determination unit for determining a body motion detection signal used for the reduction process, and the determination unit includes a pulsation component in the contact pressure detection signal from the body motion detection unit having a contact pressure sensor And determining whether to use the contact pressure detection signal as the body motion detection signal based on the determination result, and the body motion noise reduction unit When it is determined to be used as the body motion detection signal, the pulse detection device performs the body motion noise reduction processing based on the pulse wave detection signal and the contact pressure detection signal.

  In one aspect of the present invention, it is determined whether or not a pulsation component is included in the contact pressure detection signal, and based on the determination result, the contact pressure detection signal is actually used as a body motion detection signal for body motion noise reduction processing. Decide whether to use. Therefore, it is possible to use the contact pressure detection signal only when it is effective to use the contact pressure detection signal in the body motion noise reduction processing, and even when the body motion detection signal includes a pulsation component, Appropriate body motion noise reduction processing can be performed.

  In one aspect of the present invention, the determination unit uses the contact pressure detection signal as the body movement detection signal when the determination unit determines that the pulsation component is not included in the contact pressure detection signal. Processing may be performed.

  As a result, when the pulsation component is included in the contact pressure detection signal, it is possible not to use the contact pressure detection signal in the body motion noise reduction processing.

  In the aspect of the invention, the body motion detection unit includes a motion sensor, and the determination unit determines that the body motion is detected when the contact pressure detection signal determines that the pulsation component is included. The determination process using the motion detection signal from the detection unit as the body motion detection signal may be performed.

  Thereby, even when a pulsation component is included in the contact pressure detection signal, it is possible to perform body motion noise reduction processing using the motion detection signal to obtain pulsation information and the like.

  Moreover, in one aspect of the present invention, a body motion signal processing unit that performs a detection process of a fundamental frequency of the contact pressure detection signal is included, and the determination unit is based on a detection process result of the fundamental frequency of the contact pressure detection signal. Then, the determination process may be performed.

  Thereby, by calculating the basic frequency of the contact pressure detection signal, it is possible to determine whether or not a pulsating component is included in the contact pressure detection signal.

  In the aspect of the invention, the determination unit may include the pulsation component in the contact pressure detection signal when the body motion signal processing unit detects a plurality of fundamental frequencies for the contact pressure detection signal. If the body motion signal processing unit does not detect the plurality of fundamental frequencies for the contact pressure detection signal, the pulsation component is included in the contact pressure detection signal. You may decide not to.

  Thereby, depending on whether or not a plurality of fundamental frequencies are included in the contact pressure detection signal, it is determined whether to continue the determination process more strictly or to determine that the pulsation component is not included in the contact pressure detection signal. Etc. becomes possible.

  Moreover, in one aspect of the present invention, the body motion signal processing unit performs a time frequency analysis process for analyzing the plurality of fundamental frequencies when the plurality of fundamental frequencies are detected for the contact pressure detection signal, The determination unit may determine whether or not the pulsating component is included in the contact pressure detection signal based on the result of the time frequency analysis process.

  Thereby, for example, it is possible to select a contact pressure detection signal that does not include a pulsating component from contact pressure detection signals acquired from a plurality of contact pressure sensors.

  Moreover, in one aspect of the present invention, the pulse wave signal processing unit includes a pulse wave signal processing unit that acquires a pulse wave detection signal from the pulse wave detection unit, and the body motion signal processing unit includes the contact pressure detection signal. When the plurality of fundamental frequencies is detected, the fundamental frequency detection processing of the pulse wave detection signal is performed, and the determination unit is configured to perform the contact based on the detection processing result of the fundamental frequency of the pulse wave detection signal. It may be determined whether or not the pulsation component is included in the pressure detection signal.

  Thus, for example, when the body motion signal processing unit detects a plurality of fundamental frequencies for the contact pressure detection signal, the contact pressure detection signal is compared with the fundamental frequency of the contact pressure detection signal and the fundamental frequency of the pulse wave detection signal. It becomes possible to more accurately determine whether or not the signal includes a pulsating component.

  Moreover, in one aspect of the present invention, a pulsation information calculation unit that calculates pulsation information based on the pulse wave detection detection signal after the body movement noise reduction processing may be included.

  Thereby, for example, it becomes possible to present pulsation information such as the pulse rate that is easier for the user to understand intuitively than the pulse wave detection signal to the user.

  Another aspect of the invention relates to an electronic device including the pulsation detecting device, the pulse wave detecting unit, and the body motion detecting unit.

  Another aspect of the present invention relates to a program that causes a computer to function as each of the above-described units.

The basic structural example of the electronic device containing the pulsation detection apparatus of this embodiment. The structural example of the body movement noise reduction part using an adaptive filter. 3A to 3C show examples of a pulse wave detection signal, a body motion detection signal, and a waveform and frequency spectrum of a signal after body motion noise reduction processing based on the pulse wave detection signal and the body motion detection signal. 4A and 4B are examples of electronic devices including a pulsation detection device. FIGS. 5A to 5C are explanatory diagrams in a case where the pulsation component is attenuated in the body motion noise reduction processing. The detailed structural example of the electronic device containing the pulsation detection apparatus of this embodiment. The flowchart explaining the whole flow of the process of this embodiment. 8A to 8C are explanatory diagrams in the case of using an acceleration detection signal in the body movement noise reduction processing. The flowchart explaining the flow of the calculation process of a fundamental frequency. FIG. 10A to FIG. 10C are diagrams illustrating examples of detection results of fundamental frequencies. The flowchart explaining the flow of the determination process which performs a time frequency analysis process. The flowchart explaining the flow in the case of using a pulse wave detection signal also for a determination process.

  Hereinafter, this embodiment will be described. First, a basic configuration example of a pulsation detection device and an electronic device (pulse meter in a narrow sense) including the pulsation detection device will be described, and then an outline of the technique and a system configuration example of this embodiment will be described. The processing performed in this embodiment will be described in detail using a flowchart and the like.

  In addition, this embodiment demonstrated below does not unduly limit the content of this invention described in the claim. In addition, all the configurations described in the present embodiment are not necessarily essential configuration requirements of the present invention.

1. First, an example of a basic configuration of an electronic device including a pulsation detecting device will be described with reference to FIG. 1. FIG. 1 shows an example of a pulsation detection device and an electronic device, and the configuration included in the pulsation detection device and the like of this embodiment may be simplified or omitted. In some cases, the pulsation detection device or the like includes an indispensable component.

  As shown in FIG. 1, the pulsometer that is an example of the electronic apparatus of the present embodiment includes a pulse wave detection unit 10, a body motion detection unit 20, a pulsation detection device 100, and a display unit 70. However, the electronic apparatus is not limited to the configuration shown in FIG. 1, and various modifications such as omission / change of some of these components or addition of other components are possible.

  The pulse wave detection unit 10 outputs a pulse wave detection signal based on sensor information (pulse wave sensor signal) obtained from the pulse wave sensor 11. The pulse wave detection unit 10 can include, for example, a pulse wave sensor 11, a filter processing unit 15, and an A / D conversion unit 16. However, the pulse wave detection unit 10 is not limited to the configuration of FIG. 1, and various components such as omitting some of these components or adding other components (for example, an amplification unit that amplifies a signal, etc.) are included. Variations are possible.

  The pulse wave sensor 11 is a sensor for detecting a pulse wave sensor signal. For example, a photoelectric sensor can be considered. In addition, when using a photoelectric sensor as the pulse wave sensor 11, you may use the sensor comprised so that the signal component of external lights, such as sunlight, may be cut. This can be realized by, for example, a configuration in which a plurality of photodiodes are provided and difference information is obtained by feedback processing using these signals.

  The pulse wave sensor 11 is not limited to a photoelectric sensor, and may be a sensor using ultrasonic waves. In this case, the pulse wave sensor 11 has two piezoelectric elements. One of the piezoelectric elements is excited to transmit an ultrasonic wave into the living body, and the ultrasonic wave reflected by the blood flow of the living body is transmitted to the other. Received by the piezoelectric element. Since the frequency change occurs in the transmitted ultrasound and the received ultrasound due to the Doppler effect of blood flow, a signal corresponding to the blood flow can be obtained in this case as well, and pulsation information can be estimated. . Other sensors may be used as the pulse wave sensor 11.

  The filter processing unit 15 performs high-pass filter processing on the pulse wave sensor signal from the pulse wave sensor 11. Note that the cutoff frequency of the high-pass filter may be obtained from a typical pulse rate. For example, there are very few cases where the pulse rate of a normal person falls below 30 times per minute. That is, since the frequency of the signal derived from the heartbeat is rarely 0.5 Hz or less, even if the information of the frequency band in this range is cut, the adverse effect on the signal to be acquired should be small. Therefore, about 0.5 Hz may be set as the cutoff frequency. Further, depending on the situation, a different cutoff frequency such as 1 Hz may be set. Furthermore, since it is possible to assume a typical upper limit value for the human pulse rate, the filter processing unit 15 may perform bandpass filter processing instead of high-pass filter processing. The cutoff frequency on the high frequency side can be set freely to some extent, but a value such as 4 Hz may be used.

  The A / D converter 16 performs A / D conversion processing and outputs a digital signal. The process in the filter processing unit 15 described above may be an analog filter process performed before the A / D conversion process, or a digital filter process performed after the A / D conversion process. .

  The body motion detection unit 20 outputs a signal (body motion detection signal) corresponding to the body motion based on sensor information (body motion sensor signal) of various sensors. The body motion detection unit 20 can include, for example, a motion sensor (acceleration sensor) 21, a pressure sensor (contact pressure sensor) 22, a filter processing unit 24, and an A / D conversion unit 26. However, the body motion detection unit 20 may include other sensors (for example, a gyro sensor), an amplification unit that amplifies a signal, and the like. Further, it is not necessary to provide a plurality of types of sensors, and a configuration including one type of sensor may be used.

  The motion sensor 21 is, for example, the acceleration sensor 21. The acceleration sensor 21 is composed of an element whose resistance value is increased or decreased by an external force, for example, and detects triaxial acceleration information.

  The pressure sensor 22 is, for example, a contact pressure sensor 22. The contact pressure sensor 22 may be one that directly contacts a subject and measures the contact pressure, or may indirectly measure the contact pressure using a cuff structure or the like. That is, a piezoelectric element may be used, or an atmospheric pressure sensor or the like may be used.

  The filter processing unit 24 performs various filter processes on the body motion sensor signal. For example, the filter processing unit 24 performs high-pass filter processing, band-pass filter processing, or the like. However, the filtering process is not necessarily performed. The filter processing unit 24 may not be included.

  The pulsation detection device 100 includes a signal processing unit 110 and a pulsation information calculation unit 120. However, the pulsation detecting device 100 is not limited to the configuration in FIG. 1, and various modifications such as omitting some of these components or adding other components are possible.

  The signal processing unit 110 performs signal processing on an output signal (pulse wave detection signal) from the pulse wave detection unit and an output signal (body movement detection signal) from the body motion detection unit. The signal processing unit 110 can include a pulse wave signal processing unit 111, a body motion signal processing unit 113, and a body motion noise reduction unit 115.

  The pulse wave signal processing unit 111 performs various signal processes on the signal from the pulse wave detection unit 10. Note that various signals based on the pulse wave sensor signal can be considered as the output from the pulse wave detector 10 indicated by D1 in FIG. For example, since calculation of pulsation information described later is often performed based on a pulse wave sensor signal (pulse wave detection signal) after the DC component cut, D1 includes a pulse wave sensor signal after high-pass filter processing. It is assumed that However, a signal that has not been subjected to filter processing may be output, or a pulse wave sensor signal after low-pass filter processing may be output depending on circumstances. When D1 includes a plurality of signals (for example, both the pulse wave sensor signal before the high-pass filter processing and the pulse wave sensor signal after the processing), the processing in the pulse wave signal processing unit 111 is included in D1. It may be performed for all of the signals, or may be performed for some of the signals. Various processing contents are also conceivable. For example, an equalizer process for the pulse wave detection signal may be performed, or another process may be performed.

  The body motion signal processing unit 113 performs various signal processes on the body motion detection signal from the body motion detection unit 20. Similar to D1, various signals can be considered as the output from the body motion detection unit 20 indicated by D2. For example, since the motion sensor 21 and the pressure sensor 22 are included in the example of FIG. 1, the body motion detection signal of D2 includes an acceleration detection signal and a pressure detection signal (contact pressure detection signal). Since the body motion detection sensor may be another sensor such as a gyro sensor, D2 includes an output signal of a type corresponding to the type of sensor. The processing in the body motion signal processing unit 113 may be performed on all or part of the signals included in D2. For example, the signal included in D2 may be compared to perform a process of determining a signal used in the noise reduction process in the body motion noise reduction unit 115.

  In the processing in the pulse wave signal processing unit 111, a body motion detection signal may be used in accordance with the signal from the pulse wave detection unit. Similarly, in the processing in the body motion signal processing unit 113, a signal from the pulse wave detection unit 10 may be used in accordance with the body motion detection signal. In addition, a signal after a given process is performed in the pulse wave signal processing unit 111 on the output signal from the pulse wave detection unit 10 may be used for processing in the body motion signal processing unit 113. Or vice versa.

  In the pulsation detecting device 100, it is assumed that various noises are mixed in the pulse wave sensor signal acquired from the pulse wave sensor (or the pulse wave detection signal acquired therefrom). Therefore, if noise reduction processing that reduces body movement noise components included in the pulse wave sensor signal is not performed, the detected pulsation information will be affected by noise, so the value of the pulsation information is attached May not accurately represent the person's actual beat. In this case, if the pulsation information is simply output, the user's judgment based on the pulsation information may be mistaken.

  Therefore, the body motion noise reduction unit 115 performs a process of reducing noise (body motion noise component) caused by body motion from the pulse wave detection signal using the body motion detection signal. A specific example of noise reduction processing using an adaptive filter is shown in FIG. The pulse wave sensor signal acquired from the pulse wave sensor 11 includes a component caused by body movement in addition to a component caused by heartbeat. The same applies to the pulse wave detection signal (pulse wave sensor signal after the DC component cut) used for the calculation of pulsation information. Of these, components useful for the calculation of pulsation information are components caused by heartbeats, and components caused by body movements obstruct the calculation. Therefore, a signal (body motion detection signal) resulting from body motion is acquired using a body motion sensor, and a signal component correlated with the body motion detection signal (referred to as an estimated body motion noise component) is removed from the pulse wave detection signal. By doing so, the body movement noise component contained in the pulse wave detection signal is reduced. However, even if the body motion noise component in the pulse wave detection signal and the body motion detection signal from the body motion sensor are signals resulting from the same body motion, the signal level is not necessarily the same. . Therefore, an estimated body motion noise component is calculated by performing filter processing in which a filter coefficient is adaptively determined for the body motion detection signal, and a signal consisting only of the pulse wave detection signal and the calculated estimated body motion noise component The difference is taken. For example, in FIG. 2, the signal represented by h · k (n) corresponds to a signal composed only of the estimated body motion noise component.

  FIGS. 3A to 3C illustrate the above processing in terms of a frequency spectrum. FIG. 3A and the like show the time-varying waveform of the signal at the top and the frequency spectrum at the bottom. FIG. 3A shows a pulse wave detection signal before body motion noise reduction, and as shown in A1 and A2, two frequencies having large values appear in the spectrum. These A1 and A2 are called fundamental frequencies. One of the fundamental frequencies is due to heartbeat, and the other is due to body movement. Note that although there are some frequencies that are higher than A1, the high frequency components corresponding to integer multiples of A1 and A2 are not considered here. Hereinafter, high-frequency components are also seen in FIGS. 3B and 3C, but are not considered here as well.

  On the other hand, FIG. 3B shows a body motion detection signal. If there is only one type of body motion that has caused the body motion detection signal, a frequency having a large value as shown in B1 is obtained. One appears. Here, the frequency of B1 corresponds to A2 in FIG. In such a case, the signal shown in FIG. 3C is obtained by taking the difference between the pulse wave detection signal and the estimated body motion noise component by the method shown in FIG. As apparent from the figure, pulse wave detection is performed by subtracting an estimated body motion noise component having a peak B1 due to body motion from a pulse wave detection signal having two peaks A1 and A2 due to heartbeat and body motion. The body motion noise component (corresponding to A2) in the signal is removed, and as a result, the peak C1 (frequency corresponds to A1) due to the heartbeat remains.

  It should be noted that the body motion noise component included in the pulse wave detection signal corresponds to the body motion detection signal, and that the signal component that adversely affects the noise reduction processing is not included in the body motion detection signal. In the guaranteed situation, it is not necessary to perform frequency analysis in the body motion noise reduction unit 115, and therefore the frequency spectrum shown in the lower part of FIGS. 3A and 3B may not be considered. However, depending on the type of sensor used to acquire the body motion detection signal, there may be a case where the above condition is not satisfied. In that case, for example, the body motion signal processing unit 113 may process the body motion detection signal so as to satisfy the above condition, or a body motion detection signal that does not satisfy the above condition may be processed to the body motion noise reducing unit 115 or the like. May be excluded from the output. Various methods for determining whether or not the above conditions are satisfied are conceivable. For example, a frequency spectrum obtained by frequency analysis as shown in the lower part of FIGS. 3A and 3B is used. May be.

  The pulsation information calculation unit 120 calculates pulsation information based on the input signal. The pulsation information may be a pulse rate value, for example. For example, the pulsation information calculation unit 120 obtains a spectrum by performing frequency analysis such as FFT (Fast Fourier Transform) on the pulse wave detection signal after the noise reduction processing in the body motion noise reduction unit 115. Alternatively, a process may be performed in which the representative frequency in the obtained spectrum is a heartbeat frequency. In that case, a value obtained by multiplying the obtained frequency by 60 is a commonly used pulse rate (heart rate).

  The pulsation information is not limited to the pulse rate, and may be, for example, other information indicating the pulse rate (heartbeat frequency, period, etc.). Moreover, the information which represents the state of pulsation may be sufficient, for example, the value showing blood flow itself (or its fluctuation | variation) is good also as pulsation information. However, since the relationship between the blood flow rate and the signal value of the pulse wave sensor signal has individual differences for each user, when the blood flow rate or the like is used as pulsation information, correction processing is performed to deal with the individual differences. It is desirable.

  In addition, on the time-change waveform of the pulse wave detection signal input to the pulsation detection device 100, a timing at which a given value (upper peak, lower peak, or a value equal to or greater than a given threshold value) appears is detected, From the time corresponding to the timing interval, the heartbeat period may be obtained to calculate the beat information. Alternatively, the pulsation information can be calculated by transforming the waveform of the pulse wave detection signal into a rectangular wave and using the rising edge of the rectangular wave. In this case, it is not necessary to perform frequency analysis, which is advantageous in terms of calculation amount and power consumption. However, in this method, since the signal value is used as it is without being converted to the frequency axis, it is necessary to prepare the waveform to some extent. Therefore, it is desirable to perform frequency analysis in a noisy situation or the like.

  The display unit 70 (output unit in a broad sense) is for displaying various display screens used for presenting the calculated pulsation information, and can be realized by, for example, a liquid crystal display or an organic EL display.

  Specific examples in the case where the above-described electronic device is a pulse meter are shown in FIGS. 4 (A) and 4 (B). FIG. 4A shows an example of a wristwatch-type pulse meter. The base unit 400 including the pulse wave sensor 11 and the display unit 70 is attached to the left wrist 200 of the subject (user) by a holding mechanism 300 (for example, a band). FIG. 4B shows an example of a finger wearing type. A pulse wave sensor 11 is provided at the bottom of a ring-shaped guide 302 for insertion into the fingertip of the subject. However, in the case of FIG. 4B, since there is no space to provide the display unit 70, the display unit 70 (and a device corresponding to the pulsation detecting device 100 if necessary) may be provided elsewhere. is assumed.

  Although the method of the present embodiment to be described later can be applied to any type of electronic device, it is more preferable to apply the method to a wristwatch-type pulsometer (example in FIG. 4A). However, in the example of FIG. 4A, the pulse wave sensor 11 is attached to a portion where it is difficult to acquire a pulse wave sensor signal, such as the outside of the wrist (a portion in contact with the back cover surface of the wristwatch). For this reason, the amplitude of the pulse wave sensor signal output from the pulse wave sensor 11 tends to decrease as a whole. In this case, it is difficult to distinguish between a noise component and a pulsation component. Therefore, it is desirable to perform processing related to accuracy of pulsation information by various methods as in the present embodiment described later.

2. Outline of the method of this embodiment When performing body motion noise removal (reduction), a body motion detection signal is obtained from a signal acquired from a pressure sensor, a motion sensor, etc., and this is treated as a body motion noise component. Noise may also be mixed in the body motion detection signal obtained at this time. When a body motion noise component is removed (reduced) from a pulse wave sensor signal using a body motion detection signal including such noise, the detected pulsation information is also affected by the noise, The value of the pulsation information may not accurately represent the actual pulsation of the wearer as in the case where the body motion noise component is not removed (reduced).

  Furthermore, when a body movement detection signal is obtained using a contact pressure sensor as shown in Patent Document 1 described above, depending on the magnitude of the contact pressure between the contact pressure sensor and the living body (measurement site), the body The motion detection signal (contact pressure detection signal) may include a pulsation component. This is also apparent from the measurement principle of the oscillometric method, which is one of indirect methods for measuring blood pressure.

  When performing body motion noise reduction processing using a body motion detection signal containing such a pulsation component as a body motion noise component, not only the actual body motion noise component but also the pulsation component that should be detected originally May also be attenuated.

  Specifically, this is the case as shown in FIGS. The pulse wave detection signal shown in FIG. 5 (A) includes two fundamental frequencies A1 and A2, one of which uses pulsation as a signal source and the other uses body movement as a signal source. To do. Also, the contact pressure detection signal shown in FIG. 5B includes two basic frequencies B1 and B2, one of which uses pulsation as the signal source and the other uses body movement as the signal source. It is what. Then, as shown in FIG. 5C, if the body motion noise reduction processing is performed on the pulse wave detection signal in FIG. 5A using the contact pressure detection signal in FIG. Not only the noise component but also the pulsation component that should originally be detected is attenuated, and an output pulse signal having an effective amplitude for obtaining accurate pulsation information cannot be obtained.

  For this reason, there is no problem if the pressure is adjusted so that the contact pressure sensor does not detect pulsation, and the contact pressure sensor is attached, but in reality it is difficult for the user to adjust the pressure when wearing it. Is greatly impaired. Originally, for example, even when the contact pressure sensor is mounted with a pressure that detects pulsation, it is desirable to obtain pulsation information without re-mounting the sensors.

  Therefore, the pulsation detection device and the like of the present embodiment performs appropriate body movement noise reduction processing even when a pulsation component is included in the body movement detection signal. Specifically, the pulsation detection device or the like according to the present embodiment reduces the body motion noise component included in the pulse wave detection signal using the body motion detection signal determined not to include the pulsation component. Hereinafter, an example of the system configuration and details of the processing will be described in order.

3. System Configuration Example First, FIG. 6 shows a configuration example of the pulsation detection device 100 of the present embodiment and an electronic apparatus including the same.

  The pulsation detection device 100 includes a signal processing unit 110 and a pulsation information calculation unit 120. Examples of the electronic device including the pulsation detection device 100 include a pulsometer and a pedometer including the pulsation detection device 100, the pulse wave detection unit 10, the body motion detection unit 20, the display unit 70, and the like. Can be mentioned. The pulsation detection device 100 and the electronic device including the pulsation detection device 100 are not limited to the configuration shown in FIG. 6, and various modifications such as omitting some of these components or adding other components. Implementation is possible. Moreover, an electronic device may realize part or all of the functions of the pulsation detection device 100. Furthermore, some or all of the functions of the pulsation detecting device 100 of the present embodiment may be realized by a server connected by communication.

  Next, processing performed in each part of the pulsation detection device 100 will be described.

  First, the signal processing unit 110 performs various types of signal processing described below on the pulse wave detection signal from the pulse wave detection unit 10 and the body motion detection signal from the body motion detection unit 20. The signal processing unit 110 includes a pulse wave signal processing unit 111, a body motion signal processing unit 113, a determination unit 114, and a body motion noise reduction unit 115.

  Here, the pulse wave signal processing unit 111 performs signal processing on the pulse wave detection signal from the pulse wave detection unit 10. Specifically, the pulse wave signal processing unit 111 can include a frequency analysis unit 1111 and a fundamental frequency detection unit 1112.

  The frequency analysis unit 1111 performs frequency spectrum analysis processing (frequency decomposition processing) on the pulse wave detection signal. The frequency spectrum analysis process is a process for quantitatively obtaining the strength for each frequency, and is performed for a short-time region of the signal, a long-term region, or various functions. Specifically, it refers to processing such as FFT.

  The fundamental frequency detector 1112 performs a fundamental frequency detection process on the pulse wave detection signal based on the result of the frequency spectrum analysis process of the frequency analyzer 1111.

  The body motion signal processing unit 113 performs signal processing on the body motion detection signal from the body motion detection unit 20. Specifically, the body motion signal processing unit 113 can include an acceleration signal processing unit 1131 and a contact pressure signal processing unit 1132.

  Here, the acceleration signal processing unit 1131 performs various signal processing using the acceleration detection signal as the body motion detection signal. Specifically, the acceleration signal processing unit 1131 can include a frequency analysis unit 11311 and a fundamental frequency detection unit 11312.

  On the other hand, the contact pressure signal processing unit 1132 performs various signal processes using the contact pressure detection signal as a body motion detection signal. Specifically, the contact pressure signal processing unit 1132 can include a frequency analysis unit 11321 and a fundamental frequency detection unit 11322.

  The functions of the frequency analysis unit 11311 and the frequency analysis unit 11321 are the same as the functions of the frequency analysis unit 1111, and the functions of the fundamental frequency detection unit 11312 and the fundamental frequency detection unit 11322 are the same as the functions of the fundamental frequency detection unit 1112. Therefore, the description is omitted.

  The determination unit 114 performs a process of determining a body motion detection signal used for the body motion noise reduction process. For example, as described later, it is determined whether an acceleration detection signal or a contact pressure detection signal is used as the body motion detection signal.

  The body motion noise reduction unit 115 performs body motion noise reduction processing on the pulse wave detection signal from the pulse wave signal processing unit 111 based on the body motion detection signal from the body motion signal processing unit 113. The processing content of the body motion noise reduction unit 115 and the configuration of the pulsation information calculation unit 120, the pulse wave detection unit 10, the body motion detection unit 20, and the display unit 70 are the same as those in FIG. To do.

  Note that the functions of the signal processing unit 110 and each unit included in the signal processing unit 110 and the pulsation information calculation unit 120 are realized by hardware such as various processors (CPU, etc.), ASIC (gate array, etc.), programs, and the like. it can. Furthermore, the signal processing unit 110, the pulse wave signal processing unit 111, the body motion signal processing unit 113, the acceleration signal processing unit 1131, and the contact pressure signal processing unit 1132 are not limited to the configuration in FIG. Various modifications can be made such as omitting some of the components or adding other components.

4). Details of Processing of the Present Embodiment First, the overall flow of processing performed by the pulsation detecting device of the present embodiment will be described with reference to the flowchart of FIG.

  First, loop processing is started (S101), and various sensor signal data are acquired (S102). Since the signal data acquired from various sensors has different contents before and after each signal processing, they are distinguished by different names here. Therefore, we will explain various terms here.

  First, pulsation refers to a movement in which peripheral blood vessels expand or contract. Further, the pulse wave is a signal that captures a change in volume caused by the inflow of blood into the body tissue as a signal. For example, the pulse wave is obtained by irradiating a body surface with an LED from a pulse wave sensor, capturing the scattered light / reflected light with a photodiode and capturing it as a signal waveform. The pulse wave captures vasomotor reaction, not the heart motion itself, and includes noise factors other than the heart motion, for example, changes in the volume of blood vessels caused by human motion and movement. In order to correctly capture the heart motion itself and the pulse rate, it is necessary to remove this noise factor.

  In addition, pulsation refers to a movement that occurs when the periodical contraction and relaxation of the internal organs are repeated not only in the heart, but in particular here the heart periodically sends blood. The movement as a pump is called pulsation.

  Body movement, on the other hand, means moving the body in a broad sense, and in a narrow sense, it refers to steady, periodic movement of the arm (near the site where the pulse meter is worn) associated with walking, jogging, etc. .

  Further, the pulse wave sensor signal (pulse wave sensor original signal, pulse wave signal) refers to a signal itself detected by the pulse wave sensor 11. The pulse wave sensor signal includes a pulsation component signal, a body motion noise component signal, a disturbance noise component signal, and the like. Although it is considered that the arrhythmia is strictly included in the pulsation component signal, it is assumed that the arrhythmia is included in the disturbance noise component signal as an electrical signal. When it is called a pulse wave sensor original signal, it is a signal output from the pulse wave sensor, and there is an intention to emphasize that no filter processing is applied.

  Here, the pulsation component (pulsation component signal) refers to a component signal indicating a change in the volume of the blood vessel caused by the pulsation of the heart among the component signals included in the pulse wave sensor signal. . The pulsating component is often a periodic signal.

  The body motion noise component (body motion noise component signal) is the volume of blood vessels generated due to steady human movement / motion (body motion) among the component signals included in the pulse wave sensor signal. A component signal indicating a change. For example, in the case of a pulse meter attached to an arm or a finger, the volume of the blood vessel changes in accordance with the rhythm of the arm swing due to the effect of the arm swing while walking or jogging. When a human performs a steady motion in this way, the body motion noise component becomes a periodic signal, and becomes a component signal having the frequency of the motion. In addition, the body motion noise component has a feature that it has a high correlation with the waveform of a signal output from the acceleration sensor mounted in the vicinity of the site where the pulse wave sensor is mounted.

  Furthermore, disturbance noise component (disturbance noise component signal) is caused by moving or bumping around the pulse wave sensor wearing part (for example, finger, hand, arm, etc.) separately from body movement noise component. The component signal indicating the change in volume of the blood vessel. Therefore, the disturbance noise component is often an aperiodic signal.

  On the other hand, the pulse wave detection signal refers to a signal output from the pulse wave detection unit 10. Specifically, the pulse wave detection signal is filtered by the filter processing unit 15 with respect to the pulse wave sensor signal, and the A / D conversion unit 16-1 with respect to the pulse wave sensor signal after the filter processing. A signal that has undergone A / D conversion processing. However, as described above, the order of the filtering process and the A / D conversion process may be reversed.

  Next, the body motion sensor signal (body motion sensor original signal, body motion signal) refers to a signal itself detected by the body motion sensor. Specifically, the body motion sensor signal indicates a motion sensor signal indicating a signal itself detected by the motion sensor 21, a contact pressure sensor signal indicating a signal itself detected by the contact pressure sensor 22, or the like.

  Further, as shown in FIGS. 5A to 5C, the pulsation component may be included in the contact pressure sensor signal as well as the pulse wave sensor signal, and the body motion noise at this time Reduction processing is the subject of this embodiment. On the other hand, the possibility that a pulsating component is included in a motion sensor signal such as an acceleration sensor signal is extremely small, and even if included, it is so small that it can be ignored. However, while the contact pressure sensor can detect body movements such as grasping a hand, the motion sensor 21 cannot detect body movements that do not change the position of each part of the subject. Therefore, as will be described later, in this embodiment, the body pressure noise reduction process is performed using the contact pressure sensor preferentially.

  On the other hand, the body motion detection signal refers to a signal output from the body motion detection unit 20. Specifically, the body motion detection signal refers to a signal after filtering processing or A / D conversion processing is performed on the body motion sensor signal. For example, the body motion detection signal is a motion detection signal that is a signal after the above signal processing is performed on the motion sensor signal, or a pressure detection signal that is a signal after the above signal processing is performed on the pressure sensor signal. Etc. However, as described above, the order of the filtering process and the A / D conversion process may be reversed.

  As described above, in step S102, the pulse wave signal processing unit 111 acquires a pulse wave detection signal, and the body motion signal processing unit 113 acquires a body motion detection signal.

  Next, the pulse wave signal processing unit 111 performs FFT on the pulse wave detection signal for a predetermined period (for example, 16 seconds), and the body motion signal processing unit 113 performs the body motion detection signal for a predetermined period (for example, 16 seconds). FFT is performed on the image (S103). Then, the pulse wave signal processing unit 111 and the body motion signal processing unit 113 calculate the fundamental frequency included in each signal based on the result of each FFT (S104).

  Then, the determination unit 114 performs an adaptive filter input signal determination process based on the calculated fundamental frequency and the like (S105). The process of step S105 will be described in detail below.

  Next, the body motion noise reduction unit 115 performs adaptive filter processing as body motion noise reduction processing based on the input signal selected by the determination unit 114, acquires an output pulse signal, and sends it to the pulse information calculation unit 120. Output (S106).

  Thereafter, the pulsation information calculation unit 120 performs FFT on the output pulse signal (S107), and analyzes the pulse frequency based on the FFT result (S108). Then, the pulse frequency is converted into a pulse rate (S109), and the pulse rate is displayed on the display unit 70 (S110).

  Finally, it is determined whether or not to continue the measurement (S111). If it is determined that the measurement is to be continued, the processing from step S101 to step S112 is repeated. On the other hand, when it is determined that the measurement is finished, all the processes are finished.

  As shown in FIG. 6, the pulsation detection device 100 of the present embodiment described above is a body motion noise that reduces the body motion noise component included in the pulse wave detection signal from the pulse wave detection unit 10 having the pulse wave sensor 11. It includes a body motion noise reduction unit 115 that performs a reduction process, and a determination unit 114 that performs a process of determining a body motion detection signal used for the body motion noise reduction process. Then, the determination unit 114 determines whether or not a pulsation component is included in the contact pressure detection signal from the body motion detection unit 20 having the contact pressure sensor 22, and based on the determination result, determines the contact pressure detection signal. A process for determining whether to use as a body motion detection signal is performed. Furthermore, when it is determined that the contact pressure detection signal is used as the body motion detection signal, the body motion noise reduction unit 115 performs body motion noise reduction processing based on the pulse wave detection signal and the contact pressure detection signal. .

  As described above, the pulsation detection device 100 according to the present embodiment determines whether or not the pulsation component is included in the contact pressure detection signal, and actually detects the contact pressure detection signal based on the determination result. It can be determined whether or not the signal is used for the body motion noise reduction process as a signal.

  Therefore, it is possible to use the contact pressure detection signal only when it is effective to use the contact pressure detection signal in the body motion noise reduction processing, and even when the body motion detection signal includes a pulsation component, Appropriate body motion noise reduction processing can be performed.

  Thereby, for example, when the user wears a sensor or the like on the body, it is not necessary to wear the sensor while adjusting the pressure, and it is possible to provide a pulsation detecting device that is more convenient for the user.

  The body motion detection signal used for the body motion noise reduction processing is described below in addition to the above-described processing for determining whether or not to use the contact pressure detection signal as the body motion detection signal. Such processing may be performed. The body movement noise reduction processing is as described above with reference to FIGS. 2 and 3A to 3C.

  When determining that the pulsation component is not included in the contact pressure detection signal, the determination unit 114 may perform a determination process using the contact pressure detection signal as the body motion detection signal. Or the determination part 114 may perform the determination process which does not use a contact pressure detection signal as a body movement detection signal, when it is judged that a pulsation component is contained in a contact pressure detection signal.

  As a result, when the contact pressure detection signal includes a pulsation component, the contact pressure detection signal can be prevented from being used in the body motion noise reduction processing. Therefore, the pulsation component included in the pulse wave detection signal is attenuated. There is no fear. Therefore, the contact pressure detection signal can be positively used in the body motion noise reduction process. As described above, the contact pressure sensor can detect body movement such as grasping a hand, whereas the motion sensor cannot detect body movement that does not change the position of each part of the subject. . Therefore, according to the present embodiment, even when a body motion noise component that cannot be detected by a motion sensor such as grasping a hand is included in the pulse wave detection signal, it can be reduced or eliminated. Therefore, it becomes possible to obtain pulsation information more accurately than when performing body motion noise reduction processing using a motion detection signal.

  However, even if a pulsating component is included in the contact pressure detection signal, it is necessary to obtain pulsation information. In this case, it is better not to use the contact pressure detection signal. On the other hand, as described above, the possibility that a pulsating component is included in a motion sensor signal such as an acceleration sensor signal is extremely small, and even if included, it is so small that it can be ignored. In addition, as described above, there are some body movements that cannot be detected by the motion sensor, but it is better to obtain the pulsation information even if the accuracy is somewhat lower than to obtain no pulsation information at all.

  Therefore, the body motion detection unit 20 may have a motion sensor. And when the determination part 114 judges that a pulsation component is contained in a contact pressure detection signal, you may perform the determination process which uses the motion detection signal from the body movement detection part 20 as a body movement detection signal. .

  Thereby, even when a pulsation component is included in the contact pressure detection signal, it is possible to perform body motion noise reduction processing using the motion detection signal to obtain pulsation information and the like.

  As a specific example, FIGS. 8A to 8C show results when body motion noise reduction processing is performed using an acceleration detection signal. The pulse wave detection signal includes two types of basic frequencies (A1 and A2) representing pulsation and body movement, while the acceleration detection signal includes only one type of basic frequency B1 representing body movement. Absent. Therefore, even when the body movement noise reduction processing is performed using the contact pressure detection signal, even if the case is as shown in FIGS. 5A to 5C, as shown in FIG. It is possible to obtain an output pulse signal having an effective amplitude for obtaining pulsation information.

  Next, a specific method for determining whether or not a pulsation component is included in the contact pressure detection signal will be described. As described above, the pulsation is a periodic motion, and the body motion handled in this embodiment is also a periodic motion. In other words, since signals representing these are also periodic signals, in order to determine whether or not a pulsating component is included in the contact pressure detection signal, several periodic signals are included in the contact pressure detection signal. If you know if it is.

  Therefore, the pulsation detection device 100 according to the present embodiment may include a body motion signal processing unit 113 that performs detection processing of the fundamental frequency of the contact pressure detection signal. And the determination part 114 may perform a determination process based on the detection process result of the fundamental frequency of a contact pressure detection signal. That is, the determination unit 114 determines whether or not a pulsation component is included in the contact pressure detection signal based on the detection processing result of the fundamental frequency, and based on the determination result, the determination unit 114 performs contact in the body motion noise reduction processing. It may be determined whether to use the pressure detection signal.

  Here, the fundamental frequency refers to the frequency of the lowest frequency component when the signal is expressed by synthesis of sine waves (for example, Fourier series). In other words, the fundamental frequency means the repetition frequency of the minimum periodic section of the periodic signal, and is associated one-to-one with the signal source of the periodic signal. That is, if it is known how many basic frequencies are included in a signal such as a contact pressure detection signal, it is possible to specify how many signal sources of periodic signals are present. On the other hand, a frequency component that is an integral multiple of the fundamental frequency is called a harmonic. Specifically, in FIG. 5B, B1 and B2 are fundamental frequencies for different signal sources, B3 is a harmonic of B1, and B4 is a harmonic of B2. Further, since the signal source of the periodic signal that can be observed during periodic movement such as running is considered to be pulsation other than body movement, one of B1 and B2 is a body movement component and the other is a beat. It is considered to be a dynamic component.

  As a specific example, the flow of the fundamental frequency calculation process will be described using the flowchart of FIG. This process is a process performed in step S104 in FIG.

  The process shown in FIG. 9 selects 10 power spectra of the contact pressure detection signal in ascending order, compares the selected 10 brute force, and sets the frequency of one power spectrum to an integral multiple of the frequency of the other power spectrum. If it is, the power spectrum is determined to be a harmonic spectrum. If the frequency of a certain power spectrum is not an integral multiple of the frequency of any power spectrum, the power spectrum is assumed to be a fundamental frequency spectrum. Judgment.

  Hereinafter, the description will be given in order. First, the power spectra of the contact pressure detection signals are rearranged in descending order (S201), and the top 10 are set as candidates for the fundamental frequency spectrum in ascending order (S202). It should be noted that the number of power spectra to be candidates is not necessarily ten. For example, a predetermined threshold value of power spectrum is provided, and ten power spectra in ascending order and having a magnitude equal to or larger than the threshold value are candidates. You may do it. In this case, if there is no power spectrum exceeding the threshold value, “no candidate” may be set. In this case, body motion noise reduction processing may be performed using a motion detection signal.

  Next, i is changed in the range of i = 0 to 9, and the first loop processing from step S203 to step S208 is repeated.

  Further, in the first loop, j is changed in the range of j = 0 to 9, and the second loop processing from step S204 to step S206 is repeated.

  In the second loop process, it is determined whether i and j are equal (S205). If i and j are different, the result of dividing the frequency of the i-th candidate by the frequency of the j-th candidate is: It is determined whether or not it becomes an integer (S209).

  If it is determined that the result of dividing the frequency of the i-th candidate by the frequency of the j-th candidate is an integer, the second loop processing is stopped (S210), and the i-th candidate is a harmonic spectrum. Judgment is made (S211).

  On the other hand, when it is determined that the result of dividing the frequency of the i-th candidate by the frequency of the j-th candidate is not an integer, and when i and j are equal in step S205, the value of j is incremented by one, The second loop process is continued.

  If it is determined in step S206 that j is outside the range of 0 to 9, the second loop processing is terminated, and it is determined that the i th candidate is the fundamental frequency spectrum (S207).

  Further, if it is determined in step S208 that i is outside the range of 0 to 9, a list of fundamental frequencies is output (S212), and the fundamental frequency calculation process is terminated.

  Note that the calculation method of the fundamental frequency is not limited to the method described here, and can be modified.

  Thereby, by calculating the basic frequency of the contact pressure detection signal, it is possible to determine whether or not a pulsating component is included in the contact pressure detection signal.

  In addition, when the body motion signal processing unit 113 detects a plurality of fundamental frequencies for the contact pressure detection signal, the determination unit 114 determines whether or not a pulsating component is included in the contact pressure detection signal. Also good. Then, when the body motion signal processing unit 113 does not detect a plurality of fundamental frequencies for the contact pressure detection signal, it may be determined that the pulsation component is not included in the contact pressure detection signal.

  That is, when the user is performing periodic exercise such as running or walking, the body motion detection signal always includes a fundamental frequency corresponding to the body motion. Therefore, as in the example of FIG. 10A, when the body motion signal processing unit 113 does not detect a plurality of fundamental frequencies for the contact pressure detection signal, that is, does not detect fundamental frequencies other than the body motion component, When only one fundamental frequency is detected, it can be specified that the detected fundamental frequency represents a body motion component. Therefore, in this case, it may be determined that the pulsation component is not included in the contact pressure detection signal.

  However, strictly speaking, such a determination can be made only when a periodic motion is performed. This is because it may be possible that only the pulsation component is included in the contact pressure detection signal when the person is not exercising. However, since the scene in which the pulsation detection device 100 is actually used to acquire pulsation information is often in motion, even if it is determined in the same way even when the periodic motion is not performed, it is practically used. It doesn't matter.

  Thereby, depending on whether or not a plurality of fundamental frequencies are included in the contact pressure detection signal, it is determined whether to continue the determination process more strictly or to determine that the pulsation component is not included in the contact pressure detection signal. Etc. becomes possible.

  Further, when a plurality of fundamental frequencies are detected, for example, even when two fundamental frequencies are detected, they do not necessarily represent the body motion component and the pulsation component. For example, in the case of FIG. 10B, it is considered that the fundamental frequency of body movement and pulsation is detected. However, on the other hand, there are cases where the user's movement changes from running to skip while detecting the contact pressure. In this case, the fundamental frequency caused by running and the fundamental frequency caused by skipping Two fundamental frequencies are detected. This is the case as shown in FIG. Since both of these fundamental frequencies represent body motion components, this contact pressure sensor signal (contact pressure detection signal) does not include a pulsation component and may be used for body motion noise reduction processing.

  It is difficult to determine on the frequency axis that the vehicle has changed from running to skip as in this example, but if the time axis is as shown in FIG. 10C, the movement changes at a certain point. It should be easy to distinguish.

  Therefore, the body motion signal processing unit 113 may perform time frequency analysis processing for analyzing a plurality of fundamental frequencies for the contact pressure detection signal when detecting a plurality of fundamental frequencies for the contact pressure detection signal. And the determination part 114 may judge whether a pulsation component is contained in the contact pressure detection signal based on the result of a time frequency analysis process.

  Specifically, the flow of the determination process for performing the time frequency analysis process will be described using the flowchart of FIG. In the present embodiment, this process is performed in step S105 of FIG. However, it is not limited to this. Further, the present embodiment includes a case where a plurality of contact pressure sensors 22 are provided. For example, a contact pressure sensor based on a cuff structure and a contact pressure sensor using a piezoelectric element may be arranged separately.

  First, contact pressure detection signals are respectively acquired from n + 1 contact pressure sensors 22, i is changed in a range of i = 0 to n, and loop processing from step S301 to step S307 is performed (S301). Note that n is a positive integer, and here, for example, n = 2. That is, three contact pressure sensors 22 are provided.

  Next, the fundamental frequency included in the i-th contact pressure detection signal is calculated (S302). The calculation method of the fundamental frequency is as shown in FIG. Then, it is determined whether or not the i-th contact pressure detection signal includes a plurality of fundamental frequencies (S303). If it is determined that the i-th contact pressure detection signal includes a plurality of fundamental frequencies, the FFT is performed. The contact pressure detection signal for a predetermined period of time is divided into several, and a time frequency analysis is performed (S304). As the time-frequency analysis, for example, short-time Fourier analysis, wavelet transform, or the like is performed to detect a change in motion such as a change in walking pitch.

  Then, in the graph as shown in FIG. 10C created as a result of the time frequency analysis, it is determined whether there is a break in the fundamental frequency (S305). That is, it is determined whether there is a change in motion by determining whether there is a point where the fundamental frequency is suddenly changing.

  If it is determined that there is no point where the fundamental frequency is suddenly changed, the i-th contact pressure detection signal has a plurality of signal sources, that is, the i-th contact pressure detection signal includes a pulsating component. (S306), and loop processing is repeated until i = n (S307). Then, when i is outside the range of 0 to n, the process is terminated.

  On the other hand, when it is determined in step S303 that the i-th contact pressure detection signal does not include a plurality of fundamental frequencies, it can be determined that only the fundamental frequency corresponding to body movement is included. The loop process in step S307 is stopped (S308), and it is determined that the i-th contact pressure detection signal has a single signal source, that is, the i-th contact pressure detection signal does not include a pulsation component ( S309).

  Similarly, when it is determined in step S305 that there is a point where the fundamental frequency is suddenly changed, a plurality of fundamental frequencies are included, but all of them are fundamental frequencies caused by body movement. Since it can be determined, the loop processing is stopped (S308), and it is determined that the signal source of the i-th contact pressure detection signal is single (S309).

  Thereby, the contact pressure detection signal with a single signal source can be discriminated from the 0 to nth contact pressure detection signals. That is, it is possible to select a contact pressure detection signal that does not include a pulsating component from contact pressure detection signals acquired from a plurality of contact pressure sensors 22. Accordingly, it is possible to perform an appropriate body motion noise reduction process using a contact pressure detection signal that does not include a pulsating component. Even when the contact pressure detection signal cannot be used, it is possible to perform body motion noise reduction processing using the motion detection signal.

  Further, when the body motion signal processing unit 113 detects a plurality of basic frequencies for the contact pressure detection signal, the contact pressure detection signal is obtained by comparing the basic frequency of the contact pressure detection signal with the basic frequency of the pulse wave detection signal. It is possible to more accurately determine whether or not a pulsation component is included.

  Therefore, the pulsation detection device 100 of the present embodiment may include a pulse wave signal processing unit 111 that acquires a pulse wave detection signal from the pulse wave detection unit 10. And the pulse wave signal processing part 111 may perform the detection process of the fundamental frequency of a pulse wave detection signal, when the body motion signal processing part 113 detects a some fundamental frequency about a contact pressure detection signal. Furthermore, the determination unit 114 may determine whether or not a pulsation component is included in the contact pressure detection signal based on the detection processing result of the fundamental frequency of the pulse wave detection signal.

  Specifically, the flow in the case where the pulse wave detection signal is used in addition to the body movement detection signal in the determination process described above will be described with reference to the flowchart of FIG. In the present embodiment, this process is performed in step S105 of FIG. However, it is not limited to this.

  First, the fundamental frequency included in the pulse wave detection signal is calculated (S401).

  Here, when the body motion noise component is not included in the pulse wave detection signal, sufficiently accurate pulsation information can be obtained without performing the body motion noise reduction process. Therefore, in this example, it is determined whether or not the pulse wave detection signal includes a plurality of fundamental frequencies (S402), and when it is determined that the pulse wave detection signal includes only one fundamental frequency, It is determined that the body motion noise component is not included in the detection signal and only the pulsation component is included, and it is determined that the body motion noise reduction processing is not performed (S416), and the processing is terminated.

  In this case, it is possible to perform a modification such as performing body motion noise reduction processing using the motion detection signal, but it is better not to perform body motion noise reduction processing using the contact pressure detection signal. . As described above, when the user is not exercising, only the pulsation component may be included in the contact pressure detection signal. When such a contact pressure detection signal is used, body motion noise reduction processing is performed. This is because only the pulsating component of the pulse wave detection signal may be reduced.

  On the other hand, when it is determined that a plurality of fundamental frequencies are included in the pulse wave detection signal, there is a high possibility that body motion noise is included in the pulse wave detection signal. Therefore, since it is necessary to perform body motion noise reduction processing, in the following, processing for determining which body motion detection signal is used is performed.

  Here, the contact pressure detection signals are acquired from the n + 1 contact pressure sensors 22, respectively, i is changed in the range of i = 0 to n, and the first loop processing from step S403 to step S406 is performed (S403). . Note that n is a positive integer, and here, for example, n = 2. That is, three contact pressure sensors 22 are provided.

  Next, the fundamental frequency included in the i-th contact pressure detection signal is calculated (S404). The calculation method of the fundamental frequency is as shown in FIG. Then, it is determined whether or not all the fundamental frequencies in the pulse wave detection signal are included in the fundamental frequencies in the i-th contact pressure detection signal (S405).

  If there is a fundamental frequency in the pulse wave detection signal that is not included in the fundamental frequency of the i-th contact pressure detection signal, it is determined in the present embodiment that it is a pulsating component. That is, it is determined that the contact pressure detection signal includes only the body motion component and does not include the pulsation component.

  Therefore, when it is determined that there is a fundamental frequency in the pulse wave detection signal that is not included in the fundamental frequency of the i-th contact pressure detection signal, the first loop process is stopped (S407), It is determined that body motion noise reduction processing is to be performed using the i-th contact pressure detection signal that does not include a pulsation component (S408), and the processing ends.

  On the other hand, when it is determined that all the fundamental frequencies in the pulse wave detection signal are included in the fundamental frequency of the i-th contact pressure detection signal, the contact pressure detection signal includes the pulsation component in addition to the body motion component. In order to search for a contact pressure detection signal that does not include a pulsating component, the first loop processing is repeated (S406), and when i is out of the range of 0 to n, It is determined that there is no contact pressure detection signal that does not include a dynamic component, and the process ends.

  Subsequently, after the first loop process is completed, i is changed in the range of i = 0 to n, and the second loop process from step S409 to step S412 is performed (S409). In the second loop processing, the time frequency analysis is performed on the i-th contact pressure detection signal (S410), and in the graph as a result of the time frequency analysis shown in FIG. It is determined whether there is a break (S411). That is, it is determined whether or not there is a point where the fundamental frequency is suddenly changing.

  If it is determined that there is no point where the fundamental frequency is suddenly changed, the i-th contact pressure detection signal has a plurality of signal sources. It is determined that other pulsation components are included, and the second loop process is repeated until i = n in order to search for a contact pressure detection signal having a section not including the pulsation components (S412). Then, when i is outside the range of 0 to n, the second loop processing is terminated. Finally, the body motion noise reduction process is abandoned using the contact pressure detection signal, and it is determined that the body motion noise reduction process is performed using the acceleration detection signal (S413), and the entire process is terminated.

  On the other hand, if it is determined in step S411 that there is a point where the fundamental frequency is suddenly changed, a plurality of fundamental frequencies are included, but depending on the section, all may be fundamental frequencies caused by body movement. Therefore, the loop process is stopped (S414). Then, the section that does not include the fundamental frequency of the pulse wave detection signal is determined to perform body motion noise reduction processing using the i-th contact pressure detection signal, and the section that includes the fundamental frequency of the pulse wave detection signal is acceleration detection. Using the signal, it is determined that the body motion noise reduction process is to be performed, and the process ends (S415).

  Further, there are the following methods as specific determination methods for determining whether or not a pulsation component is included in each time section of the contact pressure detection signal represented on the time axis. First, on the time axis as shown in FIG. 10 (C), a signal corresponding to a part before each point at which the fundamental frequency of the contact pressure detection signal is switched is set as a first contact pressure detection signal, and after the switching point. A signal corresponding to the portion is set as a second contact pressure detection signal. Then, it is determined whether all the basic frequencies in the pulse wave detection signal are included in the basic frequency of the first contact pressure detection signal. If all the basic frequencies are included, the first contact pressure detection signal is beaten. If it is determined that the motion component is included, and there is not even one component, it is determined that the first contact pressure detection signal does not include the pulsation component. The same applies to the second contact pressure detection signal.

  Note that the processing shown in FIG. 12 can be naturally modified. For example, it may be determined that the body motion noise reduction process is performed using the acceleration detection signal after step S406 without performing the second loop process.

  Thereby, when the body motion signal processing unit 113 detects a plurality of basic frequencies for the contact pressure detection signal, the contact pressure detection signal is compared with the basic frequency of the contact pressure detection signal and the basic frequency of the pulse wave detection signal. It is possible to more accurately determine whether or not includes a pulsating component. In addition, it is possible to perform body motion noise reduction processing using a contact pressure detection signal that does not include a pulsating component among a plurality of contact pressure detection signals. Furthermore, even when the contact pressure detection signal cannot be used, it is possible to perform body motion noise reduction processing using the motion detection signal.

  Moreover, the pulsation detection device 100 of the present embodiment may include a pulsation information calculation unit 120 that calculates pulsation information based on the pulse wave detection signal after the body movement noise reduction processing. The pulsation information is as described above.

  Thereby, for example, it becomes possible to present pulsation information such as the pulse rate that is easier for the user to understand intuitively than the pulse wave detection signal to the user. In addition, when performing the above-described body motion noise reduction processing, it is possible to improve the calculation accuracy of the pulse rate.

  The above-described embodiment can also be applied to an electronic device including the pulsation detection device 100, the pulse wave detection unit 10, and the body motion detection unit 20.

  Thereby, the technique of this embodiment is applicable also to the electronic device containing the pulsation detection apparatus 100. FIG. The electronic device is specifically a pulse meter, and the configuration thereof may be the one shown in FIG. 4A or 4B, or another configuration.

  In addition, the pulsation detection device 100, the electronic device, the program, and the like according to the present embodiment may realize part or most of the processing by a program.

  As a result, the processing of this embodiment can be realized by a program. For example, the program may be a program that is read and executed by a processing unit (for example, a DSP) or the like of a device as shown in FIG.

  Further, the pulse wave detection device worn by the user may include a pulse wave sensor 11 and a communication unit that communicates a pulse wave sensor signal from the pulse wave sensor 11 wirelessly or by wire. In that case, the program of this embodiment is provided separately from the pulse wave detection device, and is read out and executed by the processing unit (for example, CPU) of the information processing system that receives the pulse wave sensor signal from the communication unit described above. Is done. This information processing system may not be assumed to be worn by a user such as a PC, or may be assumed to be worn (mobile) by a user such as a smartphone. Further, a server system or the like connected via a network such as the Internet may be used as the information processing system.

  When the pulse wave detection device and the information processing system on which the program is executed are separate, a display unit used for presenting pulsation information to the user is provided at an arbitrary location. For example, the information may be displayed on a display unit of the information processing system, or a pulse wave detection device may be provided with a display unit to display pulsation information output from the information processing system. Moreover, you may display on the display part of different apparatuses (for example, arbitrary client apparatuses, etc. when a server system is used as an information processing system).

  The above program is recorded on an information storage medium. Here, as the information recording medium, various recording media that can be read by an information processing system such as an optical disk such as a DVD or a CD, a magneto-optical disk, a hard disk (HDD), a memory such as a nonvolatile memory or a RAM can be assumed. .

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. Further, the configurations and operations of the pulsation detection device, the electronic device, and the program are not limited to those described in the present embodiment, and various modifications can be made.

10 pulse wave detection unit, 11 pulse wave sensor, 15 filter processing unit,
16 A / D converter, 20 body motion detector,
21 Motion sensor (acceleration sensor),
22 pressure sensor (contact pressure sensor), 24 filter processing unit,
26 A / D conversion unit, 70 display unit, 100 pulsation detection device, 110 signal processing unit,
111 pulse wave signal processing unit, 113 body motion signal processing unit, 114 determination unit,
115 body motion noise reduction unit, 120 pulsation information calculation unit, 300 holding mechanism,
302 guide, 400 base section, 1111 frequency analysis section,
1112 fundamental frequency detection unit, 1113 acceleration signal processing unit,
1132 contact pressure signal processing unit, 11311 frequency analysis unit,
11312 fundamental frequency detector, 11321 frequency analyzer,
11322 Fundamental frequency detector

Claims (10)

A body motion noise reduction unit that performs body motion noise reduction processing to reduce a body motion noise component included in a pulse wave detection signal from a pulse wave detection unit having a pulse wave sensor;
A determination unit that performs determination processing of a body motion detection signal used for the body motion noise reduction processing;
Including
The determination unit
It is determined whether or not a pulsation component is included in a contact pressure detection signal from a body motion detection unit having a contact pressure sensor, and the contact pressure detection signal is used as the body motion detection signal based on the determination result. Whether to determine whether or not
The body movement noise reduction unit is
When it is determined that the contact pressure detection signal is used as the body motion detection signal, the body motion noise reduction processing is performed based on the pulse wave detection signal and the contact pressure detection signal. Beat detector. In claim 1,
The determination unit
The pulsation detecting apparatus, wherein when the contact pressure detection signal is determined not to include the pulsation component, the determination process using the contact pressure detection signal as the body movement detection signal is performed. In claim 2,
The body motion detector is
Have a motion sensor,
The determination unit
When it is determined that the pulsation component is included in the contact pressure detection signal, the determination process using the motion detection signal from the body motion detection unit as the body motion detection signal is performed. Motion detection device. In any one of Claims 1 thru | or 3,
Including a body motion signal processing unit for performing processing for detecting a fundamental frequency of the contact pressure detection signal;
The determination unit
The pulsation detecting device, wherein the determination processing is performed based on a detection processing result of the fundamental frequency of the contact pressure detection signal. In claim 4,
The determination unit
When the body motion signal processing unit detects a plurality of fundamental frequencies for the contact pressure detection signal, it determines whether or not the pulsation component is included in the contact pressure detection signal,
When the body motion signal processing unit does not detect the plurality of fundamental frequencies for the contact pressure detection signal, it is determined that the pulsation component is not included in the contact pressure detection signal. Beat detector. In claim 5,
The body motion signal processor is
When the plurality of fundamental frequencies are detected for the contact pressure detection signal, a time frequency analysis process for analyzing the plurality of fundamental frequencies is performed,
The determination unit
A pulsation detection device that determines whether or not the pulsation component is included in the contact pressure detection signal based on a result of the time-frequency analysis processing. In claim 5 or 6,
Including a pulse wave signal processing unit for acquiring a pulse wave detection signal from the pulse wave detection unit;
The pulse wave signal processor is
When the body motion signal processing unit detects the plurality of fundamental frequencies for the contact pressure detection signal, performs a detection process of the fundamental frequency of the pulse wave detection signal,
The determination unit
A pulsation detection device that determines whether or not the pulsation component is included in the contact pressure detection signal based on a detection processing result of the fundamental frequency of the pulse wave detection signal. In any one of Claims 1 thru | or 7,
A pulsation detection device comprising a pulsation information calculation unit that calculates pulsation information based on the pulse wave detection detection signal after the body motion noise reduction processing. The pulsation detecting device according to any one of claims 1 to 8,
The pulse wave detector;
The body motion detector;
An electronic device comprising: A body motion noise reduction unit that performs body motion noise reduction processing to reduce a body motion noise component included in a pulse wave detection signal from a pulse wave detection unit having a pulse wave sensor;
As a determination unit that performs determination processing of a body motion detection signal used for the body motion noise reduction processing,
Make the computer work,
The determination unit
It is determined whether or not a pulsation component is included in a contact pressure detection signal from a body motion detection unit having a contact pressure sensor, and the contact pressure detection signal is used as the body motion detection signal based on the determination result. Whether to determine whether or not
The body movement noise reduction unit is
When it is determined that the contact pressure detection signal is used as the body motion detection signal, the body motion noise reduction processing is performed based on the pulse wave detection signal and the contact pressure detection signal. program.

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