JP5104842B2 - Pulse meter, control program and recording medium - Google Patents

Description

  The present invention relates to a pulsometer, a pulsometer control method, a wristwatch type information device, a control program, and a recording medium, and in particular, a pulsometer suitable for measuring a pulse while walking or running while worn on a human arm. The present invention relates to a pulse meter control method, a wristwatch type information device, a control program, and a recording medium.

For example, Patent Document 1 discloses a wristwatch type pulse meter.
The pulsometer disclosed in the above-mentioned Patent Document 1 is based on the frequency analysis result of the pulse wave signal based on the frequency analysis result of the body motion signal detected by the acceleration sensor. The frequency component having the maximum power is extracted from the frequency analysis result of the pulse wave signal from which the harmonic component of the body motion signal is removed, and the pulse rate is calculated based on the extracted frequency component. The composition was taken.

Japanese Patent No. 2816944

In the above-described conventional pulse meter, since the body motion component is detected by the acceleration sensor, not all the body motion components generated inside the living body included in the pulse sensor signal can be grasped, and the body motion component is removed. There was a fear that would be incomplete.
Conventionally, the body motion component cannot be completely grasped. Therefore, in order to remove the body motion component included in the pulse sensor signal, the body motion signal is identified using the characteristics of the harmonic component of the frequency analysis result, and the identified body motion component is detected. Since the pulse wave signal is extracted by removing the signal, if the body motion does not have a periodic characteristic, the body motion component cannot be removed, and thus the pulse can be obtained correctly. There was a problem that it was not possible.
Therefore, an object of the present invention is to more accurately grasp the body motion component included in the pulse sensor signal, so that even if the body motion component does not have periodic characteristics, An object of the present invention is to provide a pulse meter , a control program, and a recording medium capable of accurately removing a body motion component generated inside and accurately calculating a pulse rate.

In order to solve the above-described problem, the plethysmograph is an arm-mounted type pulsometer , which detects a pulse wave at the wearing site and outputs a pulse wave detection signal, and body movement caused by the influence of venous blood at the wearing site A body motion component removing unit that removes a component from the pulse wave detection signal; and a pulse rate calculating unit that calculates a pulse rate based on the pulse wave detection signal after the body motion component removal, and the body motion component The removal unit includes an angle sensor that detects the movement of the wearing part, detects the amount of change in the relative difference in the height direction between the position of the wearer's heart and the wearing part, and the angle sensor The body motion component corresponding to the change amount of the difference is removed from the pulse wave detection signal.
According to the above configuration, the pulse wave detector has the pulse wave sensor and outputs a pulse wave detection signal.
The body motion component removing unit removes the body motion component included in the pulse wave detection signal according to the relative difference in the height direction between the position of the wearer's heart and the mounting position of the pulse meter.
Thereby, a pulse rate calculation part calculates a pulse rate based on the pulse wave detection signal after a body motion component removal.
The body motion component removing unit detects a body motion component expressed as a function of a relative difference in the height direction between the position of the wearer's heart and the position of the pulsometer. You may make it provide the body movement detection part which outputs a signal.

Furthermore, the body motion component removing unit includes a difference detecting unit that detects a relative difference in a height direction between a position of the wearer's heart and a wearing position of the pulse meter, and the difference and the pulse wave detection. A body motion component generation unit configured to generate the body motion component from the signal.
In addition, the difference detection unit may include an angle sensor that detects an angle difference in an actual arrangement state with respect to a reference angle of the pulse meter as a relative difference in the height direction.
Furthermore, the angle sensor may be arranged in the vicinity of the pulse wave sensor.
The angle sensor may be arranged in a substantially stacked state on the pulse wave sensor.
Furthermore, the angle sensor may detect the angle difference based on stationary acceleration.
Further, the angle sensor may have a rotating weight and detect the angle difference based on a rotating state of the rotating weight.

Further, the difference detection unit attenuates the predetermined body motion component when the angle difference is assumed to be higher than the position of the wearer's heart. You may make it provide the angle difference correction | amendment part which correct | amends the said angle difference according to a curve.
Furthermore, the body motion component removing unit outputs a body motion component detection signal corresponding to the body motion component based on a relative difference in height between the position of the wearer's heart and the mounting position of the pulse meter. You may make it provide the removal process part which subtracts from the said pulse-wave detection signal.
The body motion component removing unit may be configured to correct the body motion component detected to be small when the wearing site is higher than the heart and remove the body motion component from the pulse wave detection signal .
In addition, the body motion component removing unit is configured to generate a body motion component detection signal corresponding to the body motion component based on a relative difference in a height direction between the position of the wearer's heart and the mounting position of the pulse meter. A first frequency analysis unit for analyzing and generating first frequency analysis data; a second frequency analysis unit for analyzing the frequency of the pulse wave detection signal to generate second frequency analysis data; and the second frequency analysis data for the second frequency analysis data. You may make it provide the removal process part which performs the subtraction process of 1 frequency analysis data.
Further, the body motion component removing unit is configured to correspond to the body motion component based on the pulse wave detection signal and a relative difference in a height direction between a position of the wearer's heart and a position where the pulse meter is worn. A filter coefficient generation unit that generates an adaptive filter coefficient based on a motion component detection signal; and a removal processing unit that subtracts the body motion component detection signal to which the adaptive filter coefficient is applied from the pulse wave detection signal. May be.

Furthermore, body motion information for detecting the pitch or the number of steps from the body motion component included in the pulse wave detection signal based on the relative height difference between the position of the wearer's heart and the position of the pulse meter. You may make it provide a detection part.
In addition, the control method of a pulsometer having a pulse wave sensor and including a pulse wave detection unit that outputs a pulse wave signal is a relative method in the height direction between the position of the wearer's heart and the mounting position of the pulsometer. A body motion component removing process for removing a body motion component included in the pulse wave detection signal based on a difference, and a pulse rate calculating process for calculating a pulse rate based on the pulse wave detection signal after the body motion component removal And may be provided .

In addition, the back surface side is covered with transparent glass and includes a case body that is held by the wearer's arm, and the pulse wave detection unit detects the pulse wave by irradiating the wearing site with light through the transparent glass. It is good also as a structure.
The case body may be constituted by a watch case having a back cover on the back surface, and the transparent glass may be fixed to an opening provided in the back cover.
Moreover, the display part which displays the pulse rate calculated by the said pulse rate calculation part on the surface side of the said case body may be provided, and the present time may be displayed on the said display part .
A wristwatch type information device equipped with a pulse wave detection unit that is mounted at a pulse wave detection position of the body, has a pulse wave sensor, and outputs a pulse wave signal, and a device main body unit that is mounted on an arm, The apparatus main body removes a body motion component that removes a body motion component included in the pulse wave detection signal based on a relative difference in the height direction between the position of the wearer's heart and the mounting position of the pulse meter. parts and, with the body movement pulse rate calculating portion to which the following components removed on the basis of the pulse wave detection signal to calculate a pulse rate, and a display unit for displaying the pulse rate, may be provided.
According to the above configuration, the body motion component removing unit of the apparatus main body is included in the pulse wave detection signal based on the relative difference in the height direction between the position of the wearer's heart and the mounting position of the pulse meter. Remove body movement components. Thereby, a pulse calculation part calculates a pulse rate based on the pulse wave detection signal after body motion component removal, and a display part displays a pulse rate.

The present invention also includes a computer for calculating a pulse rate based on a pulse wave detection signal indicating a pulse wave at the wearing site, and the computer of the pulse meter having an angle sensor for detecting the movement of the wearing site. The amount of change in the relative difference in the height direction between the position of the heart and the wearing site is detected by the angle sensor, and the body motion component due to the influence of venous blood on the wearing site corresponding to the change in the difference Is provided as a means for removing the pulse wave detection signal from the pulse wave detection signal and a means for calculating the pulse rate based on the pulse wave detection signal after the removal of the body motion component.
A pulse wave detection unit that has a pulse wave sensor and outputs a pulse wave signal; and a difference detection unit that detects a relative difference in the height direction between the position of the wearer's heart and the mounting position of the pulse meter. A control program for controlling a pulsometer with a computer based on the pulse wave component data corresponding to the pulse wave detection signal and the body motion component corresponding to the difference data The pulse rate may be calculated based on the pulse wave component after the removal of the body motion component.
Further, the control program may be recorded on a computer-readable recording medium.

  According to the present invention, the body motion component included in the pulse wave detection signal is reliably detected, and the pulse rate is calculated based on the pulse wave detection signal after the body motion component is removed. Particularly, it is possible to reliably remove a body motion component caused by venous blood, easily specify a spectrum corresponding to a pulse wave component, and improve pulse detection accuracy.

It is an explanatory view of the relationship between the pressure change amount and the body motion component amount (stroke component amount) included in the output of the pulse wave sensor. 1 is a schematic configuration diagram of a pulse measurement system according to a first embodiment. It is explanatory drawing of the example of arrangement | positioning of each sensor in a sensor module. It is a general | schematic block diagram of a pulse measuring device. An example of pulse wave detection data is arranged in a time-series order and graphed. FIG. 6 is a graph in which pressure detection data corresponding to the pulse wave detection data of FIG. 5 is arranged in time series on the same time axis. FIG. 7 is a graph in which difference data calculated from the pulse wave detection data of FIG. 5 and the pressure detection data of FIG. 6 are arranged in time series. 8 is a frequency analysis result obtained by performing FFT on the difference data in FIG. 7. It is explanatory drawing of the frequency analysis result of pulse wave detection data. It is explanatory drawing of the frequency analysis result of pressure detection data. It is explanatory drawing of the difference data which is a difference of the pulse wave detection data after frequency analysis, and the pressure detection data after frequency analysis. 1 is a schematic configuration block diagram of an example of an adaptive filter according to a first embodiment. An example of pulse wave detection data is arranged in a time-series order and graphed. FIG. 14 is a graph in which pressure detection data corresponding to the pulse wave detection data of FIG. 13 are arranged in time series on the same time axis. FIG. 14 is a graph in which residual data obtained by applying an adaptive filter to the pulse wave detection data of FIG. 13 and the pressure detection data of FIG. 14 are arranged in chronological order. 16 is a frequency analysis result obtained by performing FFT on the residual data in FIG. 15. It is a schematic block diagram of the pulse measurement system of the 3rd modification of 1st Embodiment. It is explanatory drawing of the example of arrangement | positioning of the sensor in 111 A of sensor modules. It is explanatory drawing of the example of arrangement | positioning of the sensor in the sensor module 111B. It is explanatory drawing of the relationship between the variation | change_quantity of an arm height, and the body motion component amount (stroke component amount) contained in the output of a pulse wave sensor. It is explanatory drawing of the relationship between the angle of an arm and a direction. FIG. 5 is an explanatory diagram of a relationship between an arm position height change amount and a body motion component amount (stroke component amount) as an output of an angle sensor at an arm position (arm direction) in an initial state. It is explanatory drawing of the change of the body motion component amount (stroke component amount) as an output of the angle sensor by the position of an arm when height change amount is fixed. FIG. 6 is an explanatory diagram of a relationship between an arm position height change amount at an arm position (arm direction) in an initial state and a body motion component amount (stroke component amount) included in the corrected angle sensor output. It is sectional drawing at the time of incorporating the pulse meter of 2nd Embodiment in the watch case. It is a sensor structure schematic diagram of a differential capacitor type sensor which is an angle sensor. It is a partial enlarged view of a differential capacitor type sensor. It is operation | movement explanatory drawing of a differential capacitor type sensor. It is a front view of the rotary spindle type angle sensor used as an angle sensor. FIG. 30 is a side view of the rotary spindle type angle sensor of FIG. 29. An example of pulse wave detection data is arranged in a time-series order and graphed. FIG. 32 is a frequency analysis result obtained by performing FFT on the pulse wave detection data of FIG. 31. FIG. An example of angle detection data is arranged in a graph in time series. It is a frequency analysis result obtained by performing FFT on the angle detection data of FIG. FIG. 34 is a graph in which residual data obtained by applying an adaptive filter to the pulse wave detection data of FIG. 31 and the angle detection data of FIG. 33 are arranged in chronological order. It is a frequency analysis result obtained by performing FFT on the residual data of FIG. An example of the corrected angle detection data is arranged in a time-series order and graphed. It is the frequency analysis result obtained by giving FFT to the angle detection data after correction | amendment. FIG. 37 is a graph in which residual data obtained by applying an adaptive filter to the pulse wave detection data of FIG. 31 and the corrected angle detection data of FIG. 37 are arranged in time series. It is the frequency analysis result obtained by performing FFT on the residual data of FIG.

Next, preferred embodiments of the present invention will be described with reference to the drawings.
[1] First Embodiment [1.1] Principle First, prior to specific description of the first embodiment, the operation principle of the first embodiment will be described.
The output of the pulse wave sensor for detecting the pulse wave includes various body motion components in addition to the pulse wave component. It is known that this body motion component is generated by a change in the living body due to a motion (walking / running motion, arm swing, etc.) of a user who is a pulse measurement person.
Therefore, when an acceleration sensor is used as a sensor for detecting a body motion component, the user's motion can be detected. However, the body motion component included in the output of the pulse wave sensor It is difficult to accurately detect the true body motion component contained in the output of the pulse wave sensor.
On the other hand, as the body motion component generated inside the living body, the influence of venous blood cannot be ignored as the one that most affects the optical sensor used as the pulse wave sensor.

By the way, since the vein wall is highly extensible, when the blood pressure rises, the vein wall is stretched, and a large amount of blood is stored in the portion, which increases the pressure on the body surface accompanying the expansion of the vein. I understand that.
Along with this, the inventors examined the relationship between the pressure change amount on the body surface and the body motion component amount (stroke component amount) included in the output of the pulse wave sensor when the same body motion component was generated.
FIG. 1 is an explanatory diagram of the relationship between the pressure change amount and the body motion component amount (stroke component amount) included in the output of the pulse wave sensor.
As shown in FIG. 1, it was found that the pressure change amount and the body motion component amount (stroke component amount) included in the output of the pulse wave sensor have a substantially proportional relationship.
In other words, if the amount of change in pressure on the body surface can be detected, the amount of influence of venous blood contained in the output of the pulse wave sensor can be estimated.
Therefore, in the first embodiment, the expansion of the vein, that is, the body motion component caused by the vein is detected by an external pressure sensor, and this is subtracted at a predetermined rate from the output of the pulse wave sensor, thereby The pulse rate is accurately detected based on the signal from which the influence is removed.

[1.2] Detailed Description Next, the first embodiment will be described in detail.
FIG. 2 is a schematic configuration diagram of the pulse measurement system according to the first embodiment.
The pulse measuring device 80 roughly includes a sensor module 81 attached to the user's finger, and a device main body 82 connected to the sensor module 81 via the wiring L and attached to the user's arm. .
FIG. 3 is an explanatory diagram of an arrangement example of each sensor in the sensor module.
The sensor module is roughly configured to include a pulse wave sensor 83 that mainly detects a pulse wave component and a body motion sensor 84 that is mainly configured as a pressure sensor that detects a body motion component.
Here, the pulse wave sensor 83 includes an LED 83A that emits detection light and a PD (Photo Detector) 83B that receives the detection light reflected by the human body.
FIG. 4 is a schematic configuration block diagram of the pulse measuring device.
The pulse measuring device 80 can be broadly divided into a pulse wave signal amplifying circuit 91, a body motion signal amplifying circuit 92, an A / D conversion circuit 93, and an MPU 94 in addition to the pulse wave sensor 83 and the body motion sensor 84 described above. A RAM 95, a ROM 96, and a display device 97 such as a liquid crystal display device.

In the first embodiment, a pressure sensor is used as the body motion sensor 84.
The pulse wave signal amplification circuit 91 amplifies the pulse wave detection signal output from the pulse wave sensor 83 with a predetermined amplification factor and outputs the amplified pulse wave detection signal to the A / D conversion circuit 93 as an amplified pulse wave detection signal.
The body motion signal amplification circuit 92 amplifies the pressure detection signal output from the body motion sensor 84 with a predetermined amplification factor and outputs the amplified pressure detection signal to the A / D conversion circuit 93.
The A / D conversion circuit 93 separately performs analog / digital conversion on the input amplified pulse wave detection signal and amplified pressure detection signal, and outputs them to the MPU 94 as pulse wave detection data and pressure detection data.
The MPU 94 stores the pulse wave detection data and the pressure detection data (body motion detection data) in the RAM 95, calculates the pulse rate based on the control program stored in the ROM 96, and displays it on the display device 97.
More specifically, the MPU 24 arranges the pulse wave detection data and pressure detection data (body motion detection data) stored in the RAM 25 in chronological order, and sets both the pulse wave detection data and the pressure detection data for each corresponding sampling timing. Find difference data, which is the difference.
Then, frequency analysis (FFT: Fast Fourier Transformation) of the residual data is performed to extract the harmonic component of the pulse wave, and the pulse rate is calculated from the frequency.

Next, a specific pulse rate calculation process will be described.
FIG. 5 is a graph showing an example of pulse wave detection data arranged in chronological order.
FIG. 6 is a graph in which pressure detection data corresponding to the pulse wave detection data of FIG. 5 is arranged in time series on the same time axis.
First, the MPU 94 sequentially reads out pulse wave detection data and pressure detection data stored in the RAM 95, and calculates difference data by subtracting pressure detection data at the same sampling timing from pulse wave detection data at a certain sampling timing.
FIG. 7 is a graph in which the difference data calculated from the pulse wave detection data of FIG. 5 and the pressure detection data of FIG. 6 are arranged in chronological order.
Next, the MPU 94 performs FFT on the difference data.
FIG. 8 shows frequency analysis results obtained by performing FFT on the difference data of FIG.
As a result, the obtained frequency analysis result substantially corresponds to the output signal (pulse wave component + body motion component) of the pulse wave sensor from which the body motion component due to veins is removed, that is, mainly corresponds to the pulse wave component. It becomes the pulse wave data.
Further, the MPU 94 uses the maximum frequency component from the obtained pulse wave data as a pulse spectrum, and calculates the pulse rate from the frequency.
Then, the MPU 94 displays the pulse rate on the display device 27.
As described above, according to the first embodiment, it is possible to reliably detect and grasp the fluctuation of the vein, which is the main factor of the body motion component generated inside the living body, using the pressure sensor. For this reason, a body motion component can be removed reliably, and an accurate pulse wave component detection and an accurate pulse rate measurement can be performed.

[1.3] First Modification Next, a first modification of the first embodiment will be described.
In the above description, the difference data is calculated by subtracting the pressure detection data from the pulse wave detection data before performing the frequency analysis (FFT). However, in the first modification, the pulse wave detection data and the pressure detection are calculated. It is a modification in the case of calculating difference data after performing frequency analysis of data. Hereinafter, the first modification will be described.
In the first modification, the MPU 94 performs frequency analysis (FFT) on each of the pulse wave detection data and pressure detection data (body motion detection data) stored in the RAM 95.
Next, the MPU 94 obtains difference data that is the difference between the pulse wave detection data after frequency analysis and the pressure detection data after frequency analysis.
Then, the harmonic component of the pulse wave is extracted from the obtained difference data, and the pulse rate is calculated from the frequency.

Next, a specific pulse rate calculation process will be described.
FIG. 9 is an explanatory diagram of the frequency analysis result of the pulse wave detection data.
FIG. 10 is an explanatory diagram of the frequency analysis result of the pressure detection data.
First, the MPU 94 sequentially reads out the pulse wave detection data and the pressure detection data stored in the RAM 95, performs FFT and performs frequency analysis.
FIG. 11 is an explanatory diagram of difference data which is a difference between pulse wave detection data after frequency analysis and pressure detection data after frequency analysis.
Next, the MPU 94 compares the pulse wave detection data after the frequency analysis with the pressure detection data after the frequency analysis, obtains a difference between the same frequency components, and generates difference data.
As a result, the frequency analysis result obtained as the difference data is substantially the pulse signal output signal (pulse wave component + body motion component) obtained by removing the vein-derived body motion component, that is, mainly the pulse signal. It becomes pulse wave data corresponding to the wave component.
Further, the MPU 94 uses the maximum frequency component from the obtained pulse wave data as a pulse spectrum, and calculates the pulse rate from the frequency.
Then, the MPU 94 displays the pulse rate on the display device 97.
As described above, according to the first modification of the first embodiment, it is possible to reliably detect and grasp the fluctuation of the vein, which is the main factor of the body motion component generated inside the living body. For this reason, a body motion component can be removed reliably, and an accurate pulse wave component detection and an accurate pulse rate measurement can be performed.

[1.4] Second Modification Next, a second modification of the first embodiment will be described.
In the above description, the differential data is calculated by subtracting the pressure detection data from the pulse wave detection data before or after performing the frequency analysis (FFT). However, the second modification uses an adaptive filter. It is a modification in the case of removing a body motion component from pulse wave detection data.
FIG. 12 shows a schematic configuration block diagram of an example of the adaptive filter.
The adaptive filter 100 includes a filter coefficient generation unit 101 and a synthesis unit 102 when roughly classified.
The filter coefficient generation unit 101 functions as a body motion component removal unit, and generates an adaptive filter coefficient h based on the data after the filter application output last time by the synthesis unit 102. Then, the adaptive filter coefficient h is applied to the pressure detection data (= k (n)) that functions as the input body motion component detection signal to generate body motion removal data (= h · k (n)), and a synthesis unit To 102.
The synthesis unit 102 functions as a removal processing unit, synthesizes the previously extracted pulse wave detection data (= pulse wave component + body motion component) and body motion removal data, and includes the body included in the current pulse wave detection data. The pulse component is extracted by substantially removing (subtracting) the dynamic component.

Next, a more specific pulse rate calculation process in the second modification will be described.
FIG. 13 is a graph showing an example of pulse wave detection data arranged in chronological order.
FIG. 14 is a graph in which pressure detection data corresponding to the pulse wave detection data of FIG. 13 is arranged in time series on the same time axis.
First, the MPU 94 sequentially reads out the pulse wave detection data and pressure detection data stored in the RAM 95 and outputs the pulse wave detection data at one sampling timing to the synthesis unit 102.
Further, the MPU 94 outputs pressure detection data corresponding to the pulse wave detection data output to the synthesis unit 102 to the filter coefficient generation unit 101.
As a result, the filter coefficient generation unit 101 generates the adaptive filter coefficient h based on the data after the filter application output by the synthesis unit 102 last time. The adaptive filter coefficient h is applied to the pressure detection data (= k (n)) that functions as the input body motion component detection signal, and the body motion removal data (= h · k (n)) is output to the synthesizer 102. To do.
As a result, the synthesis unit 102 synthesizes the current pulse wave data and the body motion removal data, substantially removes (subtracts) the body motion component included in the current pulse wave detection data, and obtains the pulse wave component. Extract and output residual data (= data after applying filter).
FIG. 15 is a graph in which residual data obtained by applying an adaptive filter to the pulse wave detection data of FIG. 13 and the pressure detection data of FIG. 14 are arranged in chronological order.

Next, the MPU 94 performs FFT on the residual data.
FIG. 16 shows frequency analysis results obtained by performing FFT on the residual data of FIG.
As a result, the obtained frequency analysis result substantially corresponds to the output signal (pulse wave component + body motion component) of the pulse wave sensor from which the body motion component due to veins is removed, that is, mainly corresponds to the pulse wave component. It becomes the pulse wave data.
Further, the MPU 94 calculates the pulse rate from the frequency by using the maximum frequency component from the obtained pulse wave data mainly including the pulse wave component as a pulse spectrum.
Then, the MPU 94 displays the pulse rate on the display device 97.
As described above, according to the second modification of the first embodiment, it is possible to reliably detect and grasp the fluctuation of the vein, which is the main factor of the body motion component generated inside the living body. For this reason, a body motion component can be removed reliably, and an accurate pulse wave component detection and an accurate pulse rate measurement can be performed.

[1.5] Third Modification Next, a third modification of the first embodiment will be described.
In the above description, the sensor module is provided with both the pulse wave sensor and the pressure sensor. However, in the third modified example, the sensor module is divided into two and the pulse wave sensor and the pressure sensor are separated. It is a modification in the case of mounting | wearing with a separate finger | toe.
FIG. 17 is a schematic configuration diagram of a pulse measurement system according to a third modification of the first embodiment.
The pulse measuring device 110 is roughly divided into a sensor module 111A attached to the user's first finger, a sensor module 111B attached to the user's second finger, and the sensor module 111A connected to the sensor module 111A via the wiring L1. And an apparatus main body 112 connected to the sensor module 111B via the wiring L2 and mounted on the user's arm.

FIG. 18 is an explanatory diagram of a sensor arrangement example in the sensor module 111A.
The sensor module 11A includes a pressure sensor 84 that mainly detects body motion components.
FIG. 19 is an explanatory diagram of a sensor arrangement example in the sensor module 111B.
The sensor module 111B mainly includes a pulse wave sensor 13 that detects a pulse wave component. The pulse wave sensor 83 emits a detection light and an LED 83A that receives the detection light reflected by the human body. Detector) 83B.
Since the actual detection operation is the same as that in the first embodiment described above, a detailed description thereof will be omitted.
According to the third modification, the pressure sensor 84 that mainly detects the body motion component and the pulse wave sensor 83 that mainly detects the pulse wave component are mounted on separate fingers for measurement. It is possible to reduce the influence of noise on the output signal due to the influence of the mechanical arrangement and the output signal of the other sensor.

[2] Second Embodiment [2.1] Principle First, prior to specific description of the second embodiment, the operation principle of the second embodiment will be described.
In the first embodiment, the pressure of venous blood is detected by a pressure sensor in order to detect a body movement component caused by venous blood. However, the second embodiment is an embodiment that focuses on the fact that the relative difference in the height direction between the position of the user's heart and the wearing position of the pulse meter is proportional to the pressure of the venometer. That is, in the second embodiment, the relative difference in the height direction between the position of the user's heart and the wearing position of the pulsometer is determined by using the angle around the shoulder joint of the arm wearing the pulsometer (for example, This is an embodiment in the case of detecting as 0 ° when lowered downward and 90 ° when the arm is horizontal).
Along with this, the inventors investigated the relationship between the amount of change in height (of the arm) and the amount of body motion component (stroke component amount) included in the output of the pulse wave sensor when the same body motion component was generated. It was.

FIG. 20 is an explanatory diagram of the relationship between the amount of change in arm height and the amount of body motion component (stroke component amount) included in the output of the pulse wave sensor.
As shown in FIG. 20, it was found that the height change amount and the body motion component amount (stroke component amount) included in the output of the pulse wave sensor have a substantially proportional relationship.
In other words, if the amount of change in arm height can be detected, the amount of influence of venous blood contained in the output of the pulse wave sensor can be estimated.
FIG. 21 is an explanatory diagram of the relationship between the angle and direction of the arm.
In the first embodiment, the arm angle = 0 ° when the arm is lowered directly, the direction = down, the arm angle = 90 ° when the arm is horizontal, the direction = medium, and the arm directly above. The case where the arm is raised is defined as arm angle = 180 ° and direction = up.

Also, the direction when the arm is pointed in the middle between the case where the arm is lowered directly and the case where the arm is leveled is diagonally downward, and the middle between the case where the arm is leveled and the arm is raised directly above The direction when the arm is pointed at is diagonally upward.
FIG. 22 is an explanatory diagram of the relationship between the height change amount of the arm position and the body motion component amount (stroke component amount) as the output of the angle sensor at the arm position (arm direction) in the initial state.
As shown in FIG. 22, when the position in the height direction of the arm in the initial state is equal to or less than the position of the user's heart, that is, when the direction of the arm is from the bottom, the height of the arm position is changed. Even if it did, it turned out that the change of the body motion component amount (stroke component amount) which is an output of an angle sensor shows the same tendency irrespective of the direction of any arm.
On the other hand, when the position in the height direction of the arm in the initial state is higher than the position of the user's heart, that is, when the direction of the arm is obliquely upward from above, the angle sensor is accompanied by a decrease in venous blood pressure. It can be seen that the body motion component amount (stroke component amount) as the output of the above tends to decrease overall.

FIG. 23 is an explanatory diagram of changes in the body motion component amount (stroke component amount) as the output of the angle sensor according to the arm position when the height change amount is fixed.
As shown in FIG. 23, when the arm angle is higher than 90 °, the body motion component amount as the output of the angle sensor is detected to be small.
From these results, when the arm angle is higher than 90 °, the output of the angle sensor is corrected.
FIG. 24 is an explanatory diagram of the relationship between the amount of change in the height of the arm position at the position of the arm in the initial state (arm direction) and the amount of body motion component (stroke component amount) included in the corrected angle sensor output. is there.
In this case, in the example of FIG. 22, when the arm angle is larger than 90 °, the body motion component amount (stroke component amount) Y corresponding to the output of the angle sensor is corrected by the arm angle X by the following equation. did.

Y = y · (X−90) /22.2
Where y: height change (mV)
X: Angle (degrees)
Y: Height change after correction (mV)
It is.

As a result, as shown in FIG. 24, it is possible to detect the body motion component amount (stroke component amount) included in the output of the pulse wave sensor without being affected by the arm position.
Therefore, in the second embodiment, the relative difference in the height direction between the position of the user's heart and the wearing position of the pulse meter is detected by an external angle sensor, and the body motion component caused by the vein is detected by the pulse wave sensor. The pulse rate is accurately detected based on the signal from which the influence of venous blood has been removed by subtracting it from the output at a predetermined rate.

[2.2] Detailed Description Next, the second embodiment will be described in detail.
FIG. 25 is a cross-sectional view when the pulse meter according to the second embodiment is incorporated in a watch case.
This is an example in which a pulse wave sensor 83 and an angle sensor 122 are provided on the back surface of the watch case 121 of the pulse measuring device 120.
As shown in FIG. 25, the above-described pulse wave sensor 83 is formed integrally with the main body on the back side of the watch case 121. The wristwatch case 121 is provided with a wristband 123 for attaching it to the wrist. When the wristband 123 is wrapped around the wrist, the back side of the wristwatch case 121 comes into close contact with the back of the wrist.
A transparent glass 83 </ b> C constituting the pulse wave sensor 83 is provided on the back surface side of the watch case 121. The transparent glass 83C is fixed to the watch case 121 with a back cover 124. The transparent glass 83C protects the LEDs 83A and PD83B constituting the pulse wave sensor 83 and transmits the irradiation light of the LED 13A and the reflected light obtained through the living body to enter the PD 83B.

On the surface side of the watch case 121, a display device 97 such as a liquid crystal display device that displays biological information such as the pulse rate HR based on the detection result of the pulse wave sensor 83 in addition to the current time and date is provided.
In the watch case 121, various IC circuits such as a CPU are provided on the upper side of the main substrate 126, and thereby a data processing circuit 127 is configured.
Further, a battery 128 is provided on the back side of the main board 126, and power is supplied from the battery 128 to the display device 97, the main board 126, and the pulse wave sensor 83.
The main board 126 and the pulse wave sensor 83 are connected by a heat seal 129, and power is supplied from the main board 126 to the pulse wave sensor 83 and the angle sensor 122 by wiring formed by the heat seal 129. A pulse wave detection signal is supplied from the pulse wave sensor 83 to 126, and an angle detection signal is supplied from the angle sensor 122.
The data processing circuit 127 calculates the pulse rate HR by performing FFT processing on the pulse wave signal and analyzing the processing result. Note that a button switch (not shown) is provided on the outer surface of the watch case 121 for performing time adjustment, display mode switching, and the like.
When the wristband 123 is wrapped around the wrist and attached, the back side of the watch case 121 is directed to the back of the wrist. For this reason, the light from the LED 83A is applied to the back of the wrist through the transparent glass 83C5, and the reflected light enters the PD 83B and is received.

FIG. 26 is a schematic diagram of a sensor structure of a differential capacitor type sensor used as an angle sensor. FIG. 27 is a partially enlarged view of the differential capacitor type sensor in a state where no acceleration is applied.
The differential capacitor sensor 122A is a biaxial angle sensor, and has a first sensitivity axis LX1 and a second sensitivity axis LX2.
In the differential capacitor type sensor 122A, each tether 132 having flexibility is supported by a pair of fixed shafts 131. The pair of tethers 132 support the beam 133 from both sides.
Each beam 133 is provided with an electrode 133A projecting laterally, and each fixed outer electrode is positioned at a position where the pair of fixed outer electrodes 134A and 134B have substantially the same distance from each fixed outer electrode 134A and 134B. 134 is held so as to face 134.

Thereby, the electrode 133A and the fixed outer electrodes 134A and 134B each function as a capacitor having substantially the same capacitance.
FIG. 28 is a partially enlarged view of the differential capacitor type sensor in a state where acceleration is applied.
In the state shown in FIG. 27, when the differential capacitor type sensor 122A is tilted, the tether 132 bends due to gravitational acceleration, resulting in the state shown in FIG.
As a result, for example, as shown in FIG. 28, the distance G1 between the electrode 133A and the fixed outer electrode 134A is larger than the distance G2 between the electrode 133A and the fixed outer electrode 134B. That is, the capacitance of the capacitor formed by the electrode 133A and the fixed outer electrode 134B is larger.
Therefore, this capacity difference is proportional to the magnitude of the gravitational acceleration, that is, the tilted angle. Therefore, the angle can be detected by measuring the capacity difference.

FIG. 29 is a front view of a rotary spindle type angle sensor used as an angle sensor.
FIG. 30 is a side view of the rotary spindle type angle sensor of FIG.
The rotary weight type angle sensor 122B is roughly classified into a support shaft 141, a rotary weight 142 rotatably supported by the support shaft 141, and two types of slit groups that rotate together with the rotary weight 142 and have different phases. Are formed, a fixed plate 144 that holds the support shaft 141, and an optical sensor unit 145 that is disposed at a position facing the slit plate 143 on the fixed plate 144.
With the above configuration, when the rotary weight 142 rotates due to an angle change, the optical sensor unit 145 outputs an angle detection signal having a pulse number corresponding to the rotation amount of the slit plate 143 for each slit group. At this time, since the phase relationship of the angle detection signal differs for each slit group depending on the rotation direction of the rotary weight, the change direction of the angle can also be detected.

Next, specific pulse rate calculation processing in the second embodiment will be described.
FIG. 31 is a graph showing an example of pulse wave detection data arranged in chronological order. FIG. 32 shows frequency analysis results obtained by applying FFT to the pulse wave detection data of FIG. FIG. 33 is a graph showing an example of angle detection data arranged in chronological order. FIG. 34 shows frequency analysis results obtained by performing FFT on the angle detection data of FIG.
Since the configuration of the pulse measuring device is the same as that of the first embodiment, it will be described with reference to the schematic configuration block diagram of FIG. In this case, the body motion sensor 84 is an angle sensor. The MPU 94 realizes the function of the adaptive filter shown in FIG.
First, the MPU 94 sequentially reads out the pulse wave detection data and the angle detection data stored in the RAM 95 and outputs the pulse wave detection data at a certain sampling timing to the synthesis unit 102.

In addition, the MPU 94 outputs angle detection data corresponding to each pulse wave detection data to the filter coefficient generation unit 101.
As a result, the filter coefficient generation unit 101 generates the adaptive filter coefficient h based on the data after the filter application output by the synthesis unit 102 last time. The adaptive filter coefficient h is applied to the angle detection data (= k (n)) that functions as the input body motion component detection signal, and the body motion removal data (= h · k (n)) is output to the synthesis unit 102. To do.
As a result, the synthesis unit 102 synthesizes the current pulse wave data and the body motion removal data, substantially removes (subtracts) the body motion component included in the current pulse wave detection data, and obtains the pulse wave component. Extract and output residual data (= data after applying filter).
FIG. 35 is a graph in which residual data obtained by applying an adaptive filter to the pulse wave detection data of FIG. 31 and the angle detection data of FIG. 33 are arranged in chronological order.
Next, the MPU 94 performs FFT on the residual data in FIG.

FIG. 36 shows frequency analysis results obtained by performing FFT on the residual data of FIG.
As a result, the obtained frequency analysis result substantially corresponds to the output signal (pulse wave component + body motion component) of the pulse wave sensor from which the body motion component due to veins is removed, that is, mainly corresponds to the pulse wave component. It becomes the pulse wave data.
Further, the MPU 94 calculates the pulse rate from the frequency using the maximum frequency component from the obtained pulse wave data including the pulse wave component as the pulse spectrum SP1.
Then, the MPU 94 displays the pulse rate on the display device 97.
By the way, the above explanation is for the case where the output of the angle sensor is not corrected. However, as described above, when the arm angle is higher than 90 °, the amount of body motion component as the output of the angle sensor is small. Detected small. Therefore, when the arm angle is higher than 90 °, the output of the pulse wave sensor is corrected. FIG. 37 is a graph showing an example of corrected angle detection data arranged in chronological order. FIG. 38 shows frequency analysis results obtained by performing FFT on the angle detection data after correction in FIG.
Similarly, the MPU 94 sequentially reads out the pulse wave detection data and the angle detection data stored in the RAM 95, outputs the pulse wave detection data at a certain sampling timing to the synthesis unit 102, and detects the corrected angle corresponding to each pulse wave detection data. Data is output to the filter coefficient generation unit 101.

As a result, the filter coefficient generation unit 101 generates the adaptive filter coefficient h based on the data after the filter application output by the synthesis unit 102 last time. Then, the adaptive filter coefficient h is applied to the angle detection data that functions as the input body motion component detection signal, and body motion removal data (= h · k (n)) is output to the combining unit 32. This pulse wave data and body motion removal data are combined, the body motion component contained in the current pulse wave detection data is substantially removed (subtracted), the pulse wave component is extracted, and residual data ( = Data after filter application) is output.
FIG. 39 is a graph in which residual data obtained by applying an adaptive filter to the pulse wave detection data of FIG. 31 and the corrected angle detection data of FIG. Then, FFT is applied to the residual data.
FIG. 40 shows frequency analysis results obtained by performing FFT on the residual data in FIG.
As shown in FIG. 40, the obtained frequency analysis result is the same as the frequency analysis result shown in FIG. 36 but the peak height of the pulse spectrum SP1 is not changed, but the peak heights of other spectra are suppressed, and the MPU 94 It can be seen that the pulse rate can be calculated from the frequency with the maximum frequency component from the pulse wave data as the pulse spectrum SP1 more reliably.
As described above, according to the second embodiment, it is possible to more reliably detect and grasp the fluctuation of the vein, which is the main factor of the body motion component generated inside the living body, particularly when angle correction is performed. . For this reason, a body motion component can be removed reliably, and an accurate pulse wave component detection and an accurate pulse rate measurement can be performed.

[4] Modification of First Embodiment and Second Embodiment [4.1] First Modification In the above description, a body motion sensor (pressure sensor or angle sensor) is provided in the vicinity of or separately from the pulse wave sensor. However, it is also possible to configure the body motion sensor so as to be disposed in a substantially stacked state on the pulse wave sensor in a direction away from the human body.
[4.2] Second Modification In the above description, the case where the control program is stored in advance in the ROM 96 has been described. However, the control program is stored in a recording medium such as various magnetic disks, optical disks, and memory cards. It is also possible to record in advance, read from these recording media, and install. It is also possible to provide a communication interface and download the control program via a network such as the Internet or LAN, and install and execute the program.

  80, 110 ... Pulse measuring device, 81 ... Sensor module, 82, 112 ... Device main body (watch case), 83 ... Pulse wave sensor, 83A ... LED, 83B ... PD, 83C ... Transparent glass, 97 ... Liquid crystal display device, 91 DESCRIPTION OF SYMBOLS ... Pulse wave signal amplification circuit, 92 ... Body motion signal amplification circuit, 93 ... A / D conversion circuit, 94 ... MPU, 95 ... RAM, 96 ... ROM, 97 ... Display device, 100 ... Adaptive filter, 101 ... Adaptive filter coefficient Generating unit, 102 ... combining unit, 122 ... angle sensor, 122A ... differential capacitor sensor, 122B ... rotary spindle type angle sensor.

Claims (7)

An arm-mounted pulse meter ,
A pulse wave detection unit that detects a pulse wave of the wearing part and outputs a pulse wave detection signal;
A body motion component removing unit that removes a body motion component due to the influence of venous blood at the wearing site from the pulse wave detection signal;
A pulse rate calculation unit that calculates a pulse rate based on the pulse wave detection signal after the body motion component removal,
The body motion component removing unit is
An angle sensor for detecting the movement of the wearing part; a change amount of a relative difference in a height direction between the position of the wearer's heart and the wearing part is detected by the angle sensor; and the change amount of the difference pulsimeter and removing from said pulse wave detection signal said body motion component corresponding to the. The pulse meter according to claim 1, wherein
The body motion component removing unit is
Pulse monitor, characterized in that the mounting portion is removed from the body movement component corrected by the pulse wave detection signal detected small when higher than the heart position. In the pulse meter according to claim 1 or 2,
The back side is covered with transparent glass and has a case body that is held by the wearer's arm.
The pulse wave detection unit, pulse rate monitor, characterized in that irradiating light to the mounting portion through the transparent glass to detect the pulse wave. The pulse meter according to claim 3,
It said case body, formed of a watch case having a back cover on the back, a pulse rate monitor, characterized in that fixing the transparent glass in an opening provided in the back cover. In the pulse meter according to claim 3 or 4,
On the surface side of the case body, a display unit for displaying the pulse rate calculated by said pulse rate calculating unit, a pulse rate monitor, characterized in that displays the current time on the display unit. A computer for calculating a pulse rate based on a pulse wave detection signal indicating a pulse wave of a wearing site, and having the angle sensor for detecting the movement of the wearing site, the computer of the pulse meter ,
The amount of change in the relative difference between the position of the wearer's heart and the attachment site in the height direction is detected by the angle sensor, and the body due to the influence of venous blood at the attachment site corresponding to the change in the difference Means for removing a dynamic component from the pulse wave detection signal;
A control program that functions as means for calculating a pulse rate based on the pulse wave detection signal after removal of the body motion component.   A computer-readable recording medium on which the control program according to claim 6 is recorded.

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