JP2002143108A - Measuring instrument capable of detecting information on pulse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain information on the pulse of a living body by a measuring instrument consisting of simple constitution. SOLUTION: By using a weight detector, time series data on a load value are obtained by a sampling period faster than beat sufficiently and stored in a storage device. A pulse component included in body motion are extracted from time series data on a measured body weight. The DC component of the load value is the body weight and an AC component is an acceleration pulse wave. The double integral of the load value is equivalent to a pulse wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting information on a pulse from a temporal variation of a measured load value.

[0002]

2. Description of the Related Art In general, a digital weighing scale has a configuration as shown in a block diagram of FIG. 9, and an output electric signal of a load detecting device 51 such as a strain body with a strain gauge attached thereto is amplified by an amplifying section 52. And a high-frequency component is removed through a filter circuit 53 composed of a low-pass filter. The signal from which the high-frequency component has been removed is converted from an analog signal to a digital signal by the A / D converter 54, and the microcomputer 55 calculates the weight value. The calculated weight value is displayed on the display device 56. At this time, if the measured weight value is displayed as it is over time during measurement, it is difficult to read the value. Are averaged and displayed.

[0003] It is considered that the output of the load detection sensor fluctuates because the human body vibrates minutely due to the minute vibration of the human body, that is, the body movement. Therefore, in order to stabilize the weight value to be displayed, a filter circuit is provided on the circuit side, and various averaging processes are performed on the software side. I was trying to get it. Therefore, the conventional weight scale simply measures and displays the weight of the subject.

[0004] On the other hand, an index relating to a pulse is considered to be useful because various information of the body can be obtained. This index can not only know the heartbeat function and condition of the heart, but especially the acceleration pulse wave is said to have a correlation with arteriosclerosis, and the pulse wave propagation speed is an index to know mental and physical tension. It is also said to be. Techniques for obtaining information on the pulse include a photoelectric volume pulse wave method, a measurement method using an electrocardiograph, a capacity compensation method using a cuff, a measurement method using a laser speckle, and the like.

[0005]

However, each of the above-described conventional methods for measuring a pulse has a problem. In the photoplethysmography, when external light is incident on the light receiving sensor, the measured value is affected.

[0006] In the electrocardiograph, the electrodes are attached to the skin of the chest or the limbs, so that the operation is troublesome, and since the measurer is also connected to the machine by a cable, the movement is restricted and troublesome.

[0007] In the measurement with the cuff, the arm is tightened.
It is somewhat painful for the subject during the measurement,
In addition, the device is complicated and expensive.

[0008] Measurement using laser speckle requires an optical fiber for laser light irradiation, which is also expensive.

Japanese Patent Application Laid-Open No. 60-97219 discloses that pulse information is added to the weight value, but the basis is not shown, and the determination of the pulse simply uses a certain threshold value. It is described that if it exceeds, it will be one beat.

SUMMARY OF THE INVENTION The present invention has been made in view of these problems, and it is an object of the present invention to obtain information on a pulse of a living body using a measuring device having a simple configuration, and to provide a measuring method therefor. .

[0011]

According to the present invention, there is provided a measuring device capable of detecting information on a pulse, comprising: load detecting means for detecting a load; storage means for storing time-series data of measured load values; Mean value calculating means for calculating an average value from the stored load value time-series data, and subtracting the calculated average value from the stored load value data to obtain a waveform corresponding to an acceleration pulse wave. An acceleration pulse wave calculating means for calculating the series data, and a notifying means for notifying parameters related to the pulse from the time series data of the calculated acceleration pulse wave are provided.

Further, the measuring device of the present invention capable of detecting information on a pulse calculates a time series data of a pulse wave by performing a double integration operation on a time series data of a waveform corresponding to the calculated acceleration pulse wave. Pulse wave calculating means, and the calculated pulse wave is notified to the notifying means.

Further, the measuring device of the present invention capable of detecting information relating to a pulse also notifies the notifying means of the average value of the load value time series data calculated by the average value calculating means.

Further, the measuring device of the present invention capable of detecting pulse information includes an acceleration pulse wave calculating means for calculating an acceleration pulse wave index from time-series data of a waveform corresponding to the acceleration pulse wave.

Further, the measuring device of the present invention capable of detecting information on a pulse further includes an input means for inputting an age, and a judging means for judging an arteriosclerosis level at the age from the input age and the acceleration pulse wave index. Is provided.

Further, the measuring apparatus of the present invention capable of detecting information on a pulse detects the number of peaks in a predetermined time in the time series data of the pulse wave calculated by the pulse wave calculating means, and determines the number of detected peaks. A pulse rate calculating means for calculating a pulse rate based on the pulse rate.

Further, the measuring device capable of detecting information on a pulse according to the present invention comprises: a pulse wave shape calculating means for calculating a change in the shape of the pulse wave from the time series data of the pulse wave calculated by the pulse wave calculating means; A respiratory rate calculating means for calculating a respiratory rate based on the calculated cycle of the change in the shape of the pulse wave is provided.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor considers that a minute change in body weight over time is mainly caused by a pulse, and measures a pulse wave with an electrocardiograph simultaneously with the measurement of body weight. . FIG. 1 is time series data of the weight value of a certain subject. It can be seen that the weight value does not converge to a constant value but changes periodically. In addition, a. u (Arbitrary
(Unit) is an arbitrary unit.

FIG. 2 shows an FFT for determining what frequency components are included in the time series data of the weight value.
It is the figure which performed (fast Fourier transform) processing. The X axis represents the frequency f (Hz), and the Y axis represents the power spectrum of the load (Pow).
erSpectrum). As shown in this figure, there is a portion where the spectrum is concentrated near 1 Hz. The other spectra are harmonics of 1 Hz. In other words, it can be said that the weight value changes periodically about every one second.

FIG. 3 is a diagram in which the subject's electrocardiogram is measured together with the time series data measurement of the weight value shown in FIG. 1, and only one second is extracted after the R wave is detected. Referring to this figure, the RR interval of the electrocardiogram is about 1 second, and the time when the R wave is detected is set to time t = 0 (s), and after about 0.25 seconds, a large fluctuation (point A) occurs. Has occurred. FIG. 3 is a diagram in which only a certain one second is extracted.
About 0.25 seconds after the detection of the R wave, the same fluctuation was confirmed.

Therefore, the fluctuation per second considered from the weight spectrum shown in FIG. 2 coincides with the one-second cycle of the electrocardiogram obtained from the electrocardiogram, and after the detection of the R wave in FIG. It is clear that heart movement is involved, since a large change in the load value occurs each time with approximately the same delay time.

It is considered that the vibration when blood is pumped from the heart is transmitted to the whole body using bones, muscles, and the like as a medium, and therefore, the detection value of the load sensor also fluctuates. That is, it can be said that the fluctuation is similar to that of the pulse.

That is, the time series data of the load value shown in FIG. 1 includes the acceleration pulse wave. The measured load value F is represented by F = mg + △ (m′a ′). Here, m is mass and g is gravitational acceleration.
Here, △ (m′a ′) is a vibration component, and converges to 0 when taking an integral value over a long time. If only the DC component of the load value, that is, mg is obtained, the weight value can be calculated as in the related art.

Therefore, according to the present invention, the time series data of the load value is obtained at a sampling cycle sufficiently earlier than the pulsation using the weight detection device, and is stored in the storage device.

The stored time-series data of body weight is averaged over a sufficiently long time that is equal to or longer than a beat cycle. Since the gravitational acceleration g at the measurement location is constant, the weight w = m can be calculated.

In the remainder (AC component) obtained by subtracting the DC component from the time-series data, a vibration component mainly derived from pulsation can be observed as acceleration. Although m 'is different from the body weight, it is a constant substantially determined by the individual, so that the acceleration a' is proportional to the AC component of the load value. From the above, the time series data of the load value can be rewritten as F (t) = wg + m′a ′ (t).

The pulsation component included in the body motion is extracted from the time series data of the measured weight. The DC component of the load value is the body weight, the AC component is the acceleration pulse wave, and the double integration of the load value corresponds to the pulse.

This makes it possible to calculate parameters related to the pulse, such as the pulse group, the pulse rate, and the acceleration pulse group.

[0029]

An embodiment of the present invention will be described with reference to the drawings. FIG. 4 is an external view of a measuring apparatus capable of detecting a pulse wave according to an embodiment of the present invention, and FIG. 5 is a block diagram thereof.

FIG. 4 is a perspective view showing the appearance of a measuring apparatus according to an embodiment of the present invention. As shown in FIG.
This measuring device comprises a control unit 1 for performing display and key input and a measuring unit 2 for measuring weight, which are connected by a cable 3. On the outer surface of the housing 1a of the control unit 1, a display device 5 as a notifying means, a key switch 6 as an input means, and an external input / output interface 7 are arranged.

FIG. 5 is a block diagram showing the internal configuration of the measuring device shown in FIG. The measuring apparatus is roughly divided into a control unit 1 and a measuring unit 2 as described above. As shown in FIG. 5, the control unit 1 includes a CPU for performing control and arithmetic processing related to measurement, a control and arithmetic program, ROM for storing constants and the like, RAM for temporarily storing calculation results, parameters, and the like, as well as a mean value calculating means, an acceleration pulse wave calculating means, a pulse wave calculating means, and a pulse rate calculating means having a timer, an IO port, and the like. And a microcomputer 11 which is a pulse wave shape calculating means and a respiratory rate calculating means. Also,
The control unit 1 further includes a display device 5 which is a liquid crystal display for displaying a measurement result, a measurement state, and the like, a key switch 6 for turning on / off the power of the measurement device, and inputting personal parameters, and input / output with the outside. An external input / output interface 7 for performing, a storage device 12 as a non-volatile storage means capable of storing, reading, and updating a large number of time-series data of parameters related to measurement, digital load signals, and the like.
Is provided.

On the other hand, the measuring section 2 measures the weight value of the user and outputs the measured value to the control section 1 via the cable 3. The load detecting device 21, which has a bridge structure using a strain gauge, An amplifier (AMP) 22 for amplifying a voltage signal output from the load detection device 21, an A / D converter (ADC) 23 for converting an analog signal output from the amplifier 22 to a digital signal, and outputting the digital signal to the microcomputer 4. Is provided.

Next, the operation of the measuring apparatus of this embodiment will be described. FIG. 6 is a flowchart showing the operation of the present measuring device. When the power ON / OFF button in the key switch 6 is pressed, the power of the measuring device is turned on and initialized,
It becomes possible to set personal parameters (step S
1). The user inputs his / her age using the key switch 6. The input age is temporarily stored in the storage device 12 (step S2).

Here, when the user is put on the measuring section 2, the load detecting device 21 starts measuring the load (step S3).
The sampling cycle of the load measurement needs to be sufficiently earlier than the pulsation. Generally, the pulse cycle is 3
It is said to be 00 (ms) to 1.2 (s), and in this measuring apparatus, the sampling period of the load measurement is set to 20 (ms). The measured load signals are sequentially taken into the amplifier 22 and amplified. The amplified analog load signal is supplied to the A / D converter 2
At step 3, the signal is converted into a digital load signal and stored in the storage device 12 via the microcomputer 4 (step S4). Here, it is determined whether a predetermined time has elapsed since the start of the load measurement (step S5). Here, the fixed time is set to 60 (s), and the process returns to step S3 until 60 (s) elapses, and the measurement of the load is continued. Therefore, in this measuring apparatus, 60 (s) is used at a sampling cycle of 20 (ms)
During that time, the weight is measured and the time series data of the load value is stored.

If the measurement time of 60 (s) has elapsed in step S5, the average value of all the load value data stored in the storage device 12 is calculated. The calculation of the average value is a simple average, and is calculated by dividing the value obtained by adding all the load value data by the number of data (step S6).
This calculated value is the DC component of the load value, and is the weight value of the user.

Next, the average load value calculated in step S6 is subtracted from the total load value data stored in the storage device 12 (step S7). This value is a DC component of the load value, but corresponds to the acceleration pulse wave of the user as described above.

Next, noise is removed from the time series data of the acceleration pulse wave. Here, the data is smoothed by performing a moving average process (step S8). Further, if necessary, noise may be removed by subtracting the impulse response characteristic of the mechanical resonance of the measuring unit determined by the load.

Next, the APG is calculated from the acceleration pulse wave data.
-Index (acceleration pulse wave index) is calculated (step S9). APG-Index is ranked from A to G according to age. Therefore, the calculated APG-Inde
Based on the age of the user set as x, a rank of arteriosclerosis according to the age of the user is obtained. The method of calculating the APG-Index from the acceleration pulse wave has already been described in many documents, and the determination of the level of arteriosclerosis according to the age is also a known method, and will not be described here. .

Next, data of the acceleration pulse wave calculated in step S7 is double-integrated (step S10). This integration operation is performed by software in the microcomputer 11, but it may be configured such that an integration circuit is provided on the circuit side to perform double integration. The time series data obtained by doubly integrating the acceleration pulse wave becomes the time series data of the pulse wave corresponding to the pulse wave of the user.

Next, the number of peaks is detected from the stored pulse wave data. Here, from the pulse wave waveform obtained from the pulse wave data, the peak number of the pulse wave is detected by sequentially searching the point where the wave height becomes maximum on the software (step S).
11). This is defined as a pulse rate. Many other methods for obtaining a pulse rate from a pulse wave have been proposed, but the method is not limited to this method.

Further, the respiratory rate is calculated. Here, a pulse wave shape change detecting means for detecting a change in the shape of the pulse wave is provided, and the respiratory rate is calculated according to the detected period of the change in the shape of the pulse wave. Therefore, the respiratory rate is calculated from the data on the pulse wave shape stored in the storage device 12 calculated in step S10 (step S12). The method of calculating the respiratory rate of the living body from the change in the shape of the pulse wave is described in various publications other than Japanese Patent Application Laid-Open No. 6-142082, and is omitted here.

Next, the calculated values are displayed on the display device 5. FIG. 7 is a diagram showing a result display example. in this way,
The weight value, pulse rate, respiratory rate, and APG-Index are displayed (step S13).

After a lapse of a predetermined time from the display, the power is automatically turned off, and all operations are completed (step S14).

In the above, the measuring apparatus for displaying parameters relating to the pulse by performing various processes from the measured load value has been described.

The present invention is based on the data of the measured weight value.
A parameter relating to the pulse is calculated by separating the weight value and the pulse wave component.Here, as a method of extracting the pulse wave component from the weight value, time series data of the measured weight value is sequentially stored, and a microcomputer is used. In the above, various calculations such as calculation of an average value and subtraction have been described.

However, the present invention is not limited to this, and may be extracted on the circuit side. For example, as shown in FIG. 8A, a filter circuit having both a low-pass filter and a high-pass filter capable of separating a high-frequency component and a low-frequency component is provided. If the configuration is such that the acceleration pulse wave component is detected on the high-pass filter side, data on the pulse can be extracted only on the circuit side.

Alternatively, as shown in FIG. 8B, the weight value component is extracted by passing the amplified weight value data through a low-pass filter, and the differential amplifier subtracts the weight value component from the amplified weight value data. Thus, the configuration may be such that the acceleration pulse wave component is extracted. Also in this case, it is possible to calculate the components related to the load value and the pulse on the circuit side.

Also, when the microcomputer calculates a component related to the pulse, the measured load value data is sequentially stored to calculate an average value, and the time-series data of the load value storing the average value is calculated. Instead of subtracting the average value from the measured load value data, an average value may be calculated by integrating the measured values in several samplings, and a value obtained by subtracting the average value calculated from the measured load value data may be stored.

Also, the time series data of the calculated acceleration pulse wave and pulse wave may be displayed as they are, so as to show the waveforms of these. Alternatively, the external input / output interface 7 may be used to display an image on an external display device, or may be connected to a computer to perform various analyzes on the computer.

Further, in this embodiment, the pulse rate is calculated by detecting the peak from the pulse wave data, but the average pulse interval (R-R in the electrocardiogram) is calculated by calculating each peak interval.
The remaining component obtained by calculating the interval) or excluding the pulse wave spectrum from the time series data of the pulse wave is a value derived from the body movement during the measurement of the user. Therefore, a mode may be provided in which a function of separating and measuring the pulse wave component from the measured load value data and performing and displaying the body motion is provided.

[0051]

According to the measuring device of the present invention, the load of the user is measured for a certain period of time, and parameters relating to the pulse are calculated by performing some arithmetic processing from the obtained time-series data of the load values. It is possible. With this, the measurement is not bothersome and the user does not have any pain during the measurement as in the related art, and the pulse is merely placed on the measuring device as in the case of the conventional body weight measurement. Information can be easily obtained.

Further, according to the measuring device of the present invention, various information on the pulse can be obtained by making a slight change in a program to a digital weighing scale having a simple configuration which has been conventionally used. Therefore, it becomes useful.

Therefore, according to the measuring device of the present invention, information on the pulse can be easily obtained simultaneously with the weight, which is very useful in health management.

[Brief description of the drawings]

FIG. 1 is a diagram showing time-series data of weight values.

FIG. 2 is a diagram in which weight values are subjected to FFT conversion.

FIG. 3 is a diagram showing time-series data of a weight value for one second after an R wave of an electrocardiogram is detected.

FIG. 4 is an external view of a measuring device according to an embodiment of the present invention.

FIG. 5 is a block diagram of a measuring apparatus according to the embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the measuring device according to the embodiment of the present invention.

FIG. 7 is a diagram showing a result screen of the measuring apparatus according to the embodiment of the present invention.

FIG. 8 is a block diagram according to another embodiment of the present invention.

FIG. 9 is a block diagram of a conventional scale.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control part 1a Housing 2 Measuring part 3 Cable 5, 56 Display device 6 Key switch 7 External input / output interface 11, 55 Microcomputer 12 Storage device 21, 51 Load detection device 22, 52 Amplifier 23, 54 A / D converter 53 Filter circuit

Claims (7)

[Claims] 1. Load detecting means for detecting a load, storage means for storing time-series data of measured load values,
Mean value calculating means for calculating an average value from the stored load value time-series data, and subtracting the calculated average value from the stored load value data to obtain a waveform corresponding to an acceleration pulse wave. A measuring device capable of detecting information on a pulse, comprising: acceleration pulse wave calculating means for calculating series data; and notifying means for notifying time series data of a waveform corresponding to the calculated acceleration pulse wave. 2. A pulse wave calculating means for calculating time series data of a pulse wave by performing a double integral calculation on time series data of a waveform corresponding to the calculated acceleration pulse wave, and calculating the calculated pulse wave. The measurement device capable of detecting information on a pulse according to claim 1, which notifies a notification unit. 3. The pulse-related information according to claim 1 or 2, wherein the average value of the load value time-series data calculated by the average value calculation unit is also notified to the notification unit. measuring device. 4. The apparatus according to claim 1, further comprising acceleration pulse wave index calculation means for calculating an acceleration pulse wave index from time-series data of a waveform corresponding to the acceleration pulse wave. Measuring device. 5. The apparatus according to claim 4, further comprising input means for inputting an age, and determining means for determining an arteriosclerosis level at the age from the input age and the acceleration pulse wave index. Possible measuring device. 6. A pulse rate calculating means for detecting the number of peaks in a predetermined time in the time series data of the pulse wave calculated by the pulse wave calculating means and calculating a pulse rate based on the detected peak number. A measuring device capable of detecting information on a pulse according to claim 2. 7. A pulse wave shape calculating means for calculating a shape change of a pulse wave from the time series data of the pulse wave calculated by said pulse wave calculating means, and breathing based on a period of the calculated shape change of the pulse wave. 3. A respiratory rate calculating means for calculating a number.
A measuring device capable of detecting the information on the pulse described in 1.