JP6921889B2 - Biological information measuring device - Google Patents

Description

The present invention relates to a biological information measuring device.

In recent years, the use of wearable electronic devices that can be worn has increased. Since it is possible to continuously measure biological information by wearing an electronic device, an environment is being created in which continuous measurement of heartbeat intervals can be easily performed.

In recent years, applied research on heartbeat intervals, in which heartbeat intervals continuously measured using such wearable electronic devices are used for depression detection, drowsiness detection, and the like, has been actively conducted. Examples of such applied research include those disclosed in Patent Documents 1 to 3.

In these applied studies of heart rate intervals, the difference between continuous heart rate intervals, LF (low frequency component of the power spectrum, which appears when the sympathetic nerve is activated), and HF (high frequency component of the power spectrum, parasympathetic nerve are activated). Since it is used by calculating (occasionally appearing), etc., if there is an error of several tens of ms in the heartbeat interval, it may cause a misjudgment.

Therefore, the error of the heartbeat interval needs to be as small as possible.

Japanese Unexamined Patent Publication No. 2018-33795 Japanese Unexamined Patent Publication No. 2014-168541 Japanese Unexamined Patent Publication No. 2016-150102

The present invention has been made in view of the above-mentioned current situation, and provides a practical biometric information measuring device capable of measuring a heartbeat interval with as little error as possible.

The gist of the present invention will be described with reference to the accompanying drawings.
A living body capable of measuring the heartbeat interval of a living body having a signal processing means 1 for digitizing an analog electrocardiogram signal including a QRS wave to create a digital electrocardiogram signal and a heartbeat interval measuring means 3 for measuring the heartbeat interval from the digital electrocardiogram signal. It is an information measuring device
The heartbeat interval measuring means 3 sets one peak in the QRS complex for one beat as a reference peak, measures the heartbeat interval from the interval between the reference peaks of the QRS complex for each beat, and measures the heartbeat interval. It is configured to acquire the protrusion direction information indicating whether each of the reference peaks protrudes upward or downward.
A priority direction determining means 4 for determining whether to preferentially set a peak projecting upward or downward in the QRS complex as the reference peak based on the past one or a plurality of the projecting direction information. The priority direction determining means 4 determines a direction having a large number of appearances in a predetermined number of past protruding direction information as a priority direction.
The living body is characterized in that the heart rate interval measuring means 3 is configured to give priority to a peak in the priority direction determined by the priority direction determining means 4 and set it as the reference peak in each QRS complex. It relates to an information measuring device.

Further, in the biological information measuring device according to claim 1, the heartbeat interval measuring means 3 compares the height difference of each peak in the QRS complex for one beat and sets the peak having the largest height difference as a reference peak. The present invention relates to a biological information measuring device characterized in that it is configured to perform the above.

Further, in the biometric information measuring device according to claim 2, when comparing the height difference of each peak in the QRS complex, the peak in the priority direction determined by the priority direction determining means 4 is likely to be set as the reference peak. The present invention relates to a biological information measuring device, which is provided with a height difference correction means for correcting and comparing the height difference of the peaks.

Further, in the biometric information measuring apparatus according to any one of claims 1 to 3, the signal processing means 1 relates to a biometric information measuring apparatus having a filter means for performing filtering processing.

Further, in the biometric information measuring device according to any one of claims 1 to 4, the priority direction determining means 4 is in a neutral state in which the priority direction is not determined at the time of non-measurement. It is related to.

Further, in the biometric information measuring device according to any one of claims 1 to 5, the priority direction determining means 4 gives priority to the upward direction when the number of appearances is the same in a predetermined number of past protrusion direction information. It relates to a biological information measuring device characterized in that it is determined as a direction.

Further, in the biometric information measuring device according to any one of claims 1 to 6 , when a peak in a non-priority direction determined by the priority direction determining means 4 is continuously set to the reference peak a predetermined number of times, The present invention relates to a biological information measuring device, which is configured such that the priority direction determining means 4 is in a neutral state in which a priority direction is not determined.

Since the present invention is configured as described above, it is a practical biological information measuring device capable of measuring a heartbeat interval with as little error as possible.

It is the schematic explanatory drawing of this Example. It is explanatory drawing explaining the kind of a heartbeat waveform. It is explanatory drawing explaining the error by the difference in the vertical direction of a reference peak. It is explanatory drawing explaining the error of a heartbeat interval. It is explanatory drawing which shows the example of the electrocardiogram waveform which has a peak only in one direction. It is explanatory drawing which shows the difference between the prior art example (a) and this Example (b). It is explanatory drawing which shows the difference between the prior art example (a) and this Example (b). It is the schematic explanatory drawing which shows the alternative example 1. FIG. It is the schematic explanatory drawing which shows the alternative example 2.

Embodiments of the present invention which are considered to be suitable will be briefly described by showing the operation of the present invention based on the drawings.

With the reference peak of the QRS complex (R wave, S wave or Q wave peak) of one beat of the digital electrocardiogram signal and the reference peak of other QRS waves (R wave, S wave or Q wave peak) adjacent to it. The heartbeat interval is measured from the interval of.

At this time, the heartbeat interval measuring means 3 measures the heartbeat interval and also acquires the protruding direction information of each reference peak.

The priority direction is determined by the priority direction determining means 4 based on the protruding direction information, and when the priority direction is determined, the heart rate interval measuring means 3 has a peak in this priority direction (for example, the upward direction is the priority direction). In the case of the case, the R wave) is prioritized and the reference peak is set.

The amplitude and width of each of the Q wave, R wave, and S wave changes depending on the state of the heart, individual differences, and the like (see FIG. 2). Further, even when the same person continuously measures the electrocardiogram signal, the relative height of the peak may change as shown in FIG.

For example, when a large number of heartbeat waveforms as shown in FIG. 3 (a) are mixed with waveforms as shown in FIG. 3 (b), if a reference peak is set with reference to the peak height (amplitude), FIG. 3 (a) shows. The upward peak α and the downward peak α'in FIG. 3B are used as the reference peaks, but an error occurs compared to the case where the upward peaks are continuously measured as the reference peaks, and the heartbeat interval Also causes an error.

Specifically, as shown in FIG. 4, when the heartbeat interval is measured with the downward peak α'as the reference peak immediately after the upward peak α is used as the reference peak (T1, T2), the upward direction Compared with the case where the peak α of is continuously set as the reference peak (TC1, TC2), an error (ERR) occurs in the position (reference position) of the reference peak, and an error also occurs in the heartbeat interval.

Here, assuming that TC1 and TC2, which are the correct heartbeat intervals, are TC1 = TC2, the heartbeat intervals including the error are T1 and T2, and the error of the reference peak position (reference position) is ERR, the result is as follows.
T1 = TC1 + ERR
T2 = TC2-ERR

Here, the difference between T1 and T2, which are continuous heartbeat intervals, is as follows.
T1-T2 = (TC1 + ERR)-(TC2-ERR) = (TC1 + ERR)-(TC1-ERR) = 2ERR

Therefore, when the reference peak changes (when the peak whose protrusion direction is different from the immediately preceding reference peak becomes the reference peak), the difference in the heartbeat interval before and after the change becomes twice the error of the reference position.

In this respect, the present invention makes it easy to continuously set the peak in the priority direction as the reference peak even if the amplitude of the peak fluctuates, so that the change of the reference peak is suppressed and the fluctuation of the heartbeat interval is also suppressed. Therefore, it becomes possible to measure the heartbeat interval with a smaller error.

Specific examples of the present invention will be described with reference to the drawings.

In this embodiment, the heartbeat interval of a living body having a signal processing means 1 for digitizing an analog electrocardiogram signal including a QRS complex to create a digital electrocardiogram signal and a heartbeat interval measuring means 3 for measuring the heartbeat interval from the digital electrocardiogram signal. The heartbeat interval measuring means 3 sets one peak in the QRS complex for one beat as a reference peak, and the reference peak for each one beat of the QRS complex. It is configured to measure the heartbeat interval from the interval between the peaks and to acquire the protrusion direction information indicating whether each reference peak protrudes upward or downward, respectively, and one or more of the past It has a priority direction determining means 4 for determining whether to preferentially set a peak protruding upward or downward in the QRS complex as the reference peak based on the protruding direction information, and measures the heartbeat interval. The means 3 is configured to give priority to the peak in the priority direction determined by the priority direction determining means 4 and set it as the reference peak in each QRS complex.

Specifically, this embodiment has a plurality of electrodes 2 that come into contact with a living body to acquire an electrocardiogram, and is wearable to the living body, and this wearable biological information measuring device (measuring device). The heartbeat interval and the like measured in () are transmitted (output) to an analyzer separate from the measuring device, and detailed analysis is performed by this analyzer, which is as compact and lightweight as possible.

Each part will be specifically described with reference to FIG.

The signal processing means 1 processes an analog electrocardiogram signal extracted from a potential difference between electrodes 2 in contact with a living body with an AD converter or the like to obtain a digital electrocardiogram signal.

Further, the signal processing means 1 has a filtering means that removes only signals unnecessary for detecting the heartbeat interval (performs filtering processing). As the filter means, for example, a low-pass filter, a high-pass filter, a band-pass filter, a band-stop filter and the like can be appropriately used. The electrocardiogram signal that has passed through the filtering means is sampled at equal time intervals and converted into a digital signal.

Examples of signals to be removed by the filter means include signals having high frequency components exceeding the Nyquist frequency of the AD converter, hum noise, myoelectric noise, external noise, and the like. Since the heartbeat interval changes when the waveform is distorted, a filter means having a low distortion rate and a high linearity is desired. The electrocardiogram signal after removing unnecessary signals such as noise is used for detecting the heartbeat interval. Signals having high frequency components exceeding the Nyquist frequency of the AD converter may be removed after sampling. The sampling interval for digitization shall be 250 Hz or higher. Therefore, it is possible to measure the heartbeat interval of 4 ms or less.

The heartbeat interval measuring means 3 in which the digital electrocardiogram signal digitized as described above is input in the signal processing means 1 sets one peak in the QRS complex for one beat as a reference peak, and sets each one beat as the reference peak. The heartbeat interval is measured from the interval between the reference peaks of the QRS complex of the minute, and the protrusion direction information indicating whether each reference peak protrudes upward or downward is acquired. The heartbeat interval is sent to the heartbeat interval output means 5, and the protruding direction information is sent to the priority direction determining means 4.

In this embodiment, the heartbeat interval measuring means 3 compares the height difference of each peak in the QRS complex for one beat, sets the peak with the largest height difference as the reference peak, and sets the QRS wave for each beat as the reference peak. It is configured to measure the heartbeat interval from the interval between the reference peaks.

Further, in this embodiment, it is determined whether to preferentially set the peak protruding upward or downward in the QRS complex as the reference peak based on the past one or a plurality of the protruding direction information. The priority direction determining means 4 is provided, and the heartbeat interval measuring means 3 preferentially sets a peak in the priority direction determined by the priority direction determining means 4 to the reference peak in each QRS complex. ..

That is, the protruding direction information of each reference peak acquired by the heartbeat interval measuring means 3 is sequentially accumulated in the priority direction determining means 4, and the priority direction is determined based on the past protruding direction information, and the heartbeat interval measuring means 3 is used. Sent.

Further, when the heart rate interval measuring means 3 compares the height difference of each peak in the QRS complex, the peak in the priority direction determined by the priority direction determining means 4 can be easily set as the reference peak. It is provided with a height difference correction means for correcting and comparing the height difference of the peak.

Further, the priority direction determining means 4 is in a neutral state (a state in which the priority direction is not specified) in which the priority direction is not determined at the time of non-measurement, and the projecting direction information (upward direction) of each reference peak sequentially accumulated after the start of measurement. Or downward) to determine the priority direction.

Further, in the present embodiment, the priority direction determining means 4 determines a direction having a large number of appearances in a predetermined number of past protruding direction information as a priority direction. At this time, if the number of appearances is the same in the predetermined number of past protrusion direction information, the upward direction is determined as the priority direction.

When peaks in the non-priority direction determined by the priority direction determining means 4 are continuously set to the reference peak a predetermined number of times, the priority direction determining means 4 resets all the accumulated reference peak protrusion direction information and is neutral. It is configured to be in a state.

The heart rate interval output means 5 uses the heart rate interval by wirelessly or wiredly transmitting the obtained heart rate interval, storing it in the biometric information measuring device, displaying it by the display means provided in the biometric information measuring device, or using the heartbeat interval. It is an output or the like to pass the heartbeat interval to the means.

Hereinafter, the reason why the heart rate interval measuring means 3 and the priority direction determining means 4 are configured as described above will be described in detail.

The heartbeat interval measuring means 3 uses the peak having the largest height difference (the apex of the Q wave, R wave, or S wave) as a reference peak, and sets the time interval between the reference peaks as the heartbeat interval. The reference peak of the heartbeat interval may be an upward peak or a downward peak of the waveform. This is because the waveform shape of the electrocardiogram signal does not change significantly except for abnormal cardiac conditions such as premature ventricular contraction and sudden bundle branch block. Therefore, regardless of which peak is used as the reference position for the heartbeat interval, the heartbeat interval This is because the difference between them is small.

The QRS complex of the heartbeat waveform (a signal in the same frequency band as the electrocardiogram in the definition of the electrocardiogram signal and representing the contraction of the ventricle of the heart) is generally a downward peak Q wave and an upward peak Q wave. It is represented by a peak R wave and a downward peak S wave (FIG. 2 (a)). For the sake of simplicity, P wave, T wave, U wave, δ wave, ε wave, J wave and the like other than Q wave, R wave and S wave will be omitted.

The amplitude and width of the Q wave, R wave, and S wave change depending on the state of the heart and individual differences. In an extreme case, one of the Q wave, the R wave, and the S wave does not exist as shown in FIGS. 2 (b) and 2 (c), or a plurality of Q waves, R waves, and S waves exist as shown in FIGS. There are R'waves and S'waves).

Here, the reason why the reference peak is not set only for the peak in only one direction (only in the upward direction or only in the downward direction) will be described. FIG. 5 shows a waveform in which a peak occurs in only one of the upper and lower sides. If the reference peak is set only for the peak in only one direction, the reference peak position of the heartbeat interval is not set when the heartbeat waveform of the electrocardiogram signal is input only for the peak in the direction opposite to the limited direction. The interval cannot be detected and is not detected. Therefore, it is not possible to take measures to set a peak in only one direction as a reference peak.

As a countermeasure for this problem, in this embodiment, when there are many upward reference peaks in the past (the number of upwards is large in the protruding direction information for the past n beats accumulated in the priority direction determining means 4). In the next detection by the heartbeat interval measuring means 3, the upward peak is preferentially set as the reference peak, and when there are many downward reference peaks, the downward peak is preferentially set as the reference peak in the next detection. Set to. When the upward peak is prioritized, the height difference correction means is configured so that the upward peak raises the amplitude between the peaks and the downward peak raises the amplitude between the peaks. On the contrary, when the downward peak is prioritized, the upward peak increases the amplitude between peaks, and the downward peak increases the amplitude between peaks. The details of the height difference correction means will be described later.

Here, the amplitude between the peak in the upward direction and the peak in the downward direction will be described. The amplitude of the upward peak is the height difference from the downward peak to the upward peak when there is a downward peak immediately before the upward peak, and there is no downward peak immediately before the upward peak. In the case, the height difference from the steady state to the upward peak is used. The amplitude of the downward peak is the height difference from the upward peak to the downward peak when there is an upward peak immediately before the downward peak, and there is no upward peak immediately before the downward peak. In the case, the height difference from the steady state to the downward peak is used.

In the priority direction determining means 4, the priority direction is determined in the direction in which the number of occurrences is large in the protruding direction information of the peak set as the reference peak in the heartbeat waveform of the electrocardiogram signal for the past n beats as described above. If the number of appearances is the same, the upward direction is determined as the priority direction. The reason for giving priority to the upward direction is that it is desired to give priority to the peak corresponding to the upward R wave, which is the original target of the heartbeat interval. If n is small, the priority direction is likely to change, and it does not make sense to take measures. If there is a large amount of n, the state will not change even in a situation where the priority direction must be changed, which will have an adverse effect. Therefore, n needs to be an appropriate value. The optimum value of n differs depending on the signal processing means 1 and the heart rate interval measuring means 3, but it is desirable to set it to a value of 4 or more and 64 or less in consideration of adverse effects. Further, considering the efficiency of calculation, it is desirable to limit it to a power of 2 (4,8,16,32,64). If n is less than 4, the meaning of specifying the priority peak is diminished, and n is 65 or more (since it is necessary to take a power of 2 to increase processing efficiency, the next n when considering processing efficiency is 128. When the waveform shape changes, it means that the priority direction changes after the heartbeat interval is 1 second and n is 128 for 2 minutes or more, and the priority direction is fixed too much. May have an adverse effect.

Next, the height difference correction means will be described in detail. The degree of priority (degree of correction by the height difference correction means. Priority Φ) is set as follows.

When the position of the current waveform is x and the amplitude of the heartbeat waveform of the immediately preceding electrocardiogram signal (amplitude of the detected peak) is Amp (x-1), the priority Φ is as follows.
Φ = Amp (x-1) φ

Here, φ is a parameter for setting the priority. If φ is not set to an appropriate value, the same adverse effects as n will occur. Considering the harmful effects as in n, it is desirable that the value of φ is in the range of 0.1 or more and 0.9 or less. If it is less than 0.1, there is almost no effect of giving priority to the peak, and if it exceeds 0.9, it is given too much priority, so that it does not change when the priority direction of the peak should be changed.

When comparing the amplitude (Peak to Peak) of the previous waveform using this Φ, if the current peak is in the priority direction, "Amp (x)" and "Amp (x-1) -Φ" By comparing with, it is easy to determine that the amplitude is larger than the immediately preceding amplitude (it is easy to set the reference peak).

In the case where the current peak does not have priority, it is easy to determine that the amplitude is smaller than the immediately preceding amplitude by comparing "Amp (x)" and "Amp (x-1) + Φ".

When the same person continuously measures the heartbeat waveform of the electrocardiogram signal, the waveform shape of the electrocardiogram signal rarely changes significantly except for the abnormal state of the heart, so it is not necessary to actively follow the shape change of the waveform. As a countermeasure when the waveform shape changes during measurement, if the detection direction (reference peak direction) differs from the priority direction m times in a row without changing the latest priority direction, the priority direction changes. It is considered to be. Possible causes of the change in the corrugated shape include changes in breathing, posture, exercise state, sweating state, contact position with the living body due to misalignment of the electrode 2, contact state between the electrode 2 and the living body, and the like.

If the number of times of m described above is not set appropriately, an error may occur in the heartbeat interval. Therefore, considering that n is 4 or more and 64 or less, m is set to 4 or more and n / 2 or less. If m is small, the effect of the priority direction determining means 4 cannot be obtained, and if m is large, the protruding direction information (upward peak (R wave) or downward peak) as ancillary information of the stored heartbeat interval is obtained. The meaning of resetting (information indicating whether it is (S wave)) is lost. When n is 7 or less, the priority direction is changed by the normal judgment of the priority direction and it does not make sense, so this measure is not included.

When the number of occurrences of the protruding direction information acquired together with the heartbeat interval is the same in the vertical direction, the peak in the upward direction (R wave) is prioritized. It may occur when the history of the protruding direction information of the heartbeat interval to be saved is an even number, or when "neutral" information remains after sufficient time has not passed since the initialization. The neutral state in the priority direction determining means 4 of the present embodiment means a state in which all the protruding direction information for the past n beats is filled with "neutral" information that is neither upward nor downward.

When all the information on the protruding direction of the past heartbeat interval is "neutral" in the initial state or the like, Amp (x-1) does not exist and the priority Φ cannot be determined. Therefore, the neutral state is set in which the priority direction is not determined. From the second time onward, the priority direction is determined based on the past protrusion direction information (new protrusion direction information is saved and the oldest protrusion direction information is deleted).

How the reference peak (reference position) detected between the present embodiment and the conventional example changes will be described below with reference to FIGS. 6 and 7.

The broken line circles (upward peak α, downward peak α') shown in FIGS. 6 and 7 are peaks set as reference peaks (reference positions).

FIG. 6 shows a method of always detecting the upward peak α and detecting the downward peak α'only when the upward peak α cannot be detected (FIG. 6 (a). Conventional example) and the present embodiment (FIG. 6). This is a comparison with 6 (b)).

In the conventional example, when the upward peak α can be detected in the waveforms A11 and A13 and the upward peak α cannot be detected in the waveforms A12 and A14, the positions of the detected peaks (reference peaks) change alternately up and down.

On the other hand, in this embodiment, assuming that the downward direction is prioritized when detecting the waveform A21, the height difference between the peaks of the waveforms A21, A22, A23 and A24 is the amplitude of the upward peak (from the steady position). The amplitude of the downward peak (the height difference from the upward peak to the downward peak, which is the reference position) is larger than the upward peak (height difference to the upward peak), and the priority direction is the same, so the downward peak α'can always be the reference position.

FIG. 7 is a comparison between a method of detecting a peak having a large height difference (FIG. 7 (a), a conventional example) and this embodiment (FIG. 7 (b)).

In the waveforms B11 and B13 of the conventional example, the downward peak is lower on the right side than on the left side, so the amplitude of the upward peak (the upward peak immediately before the reference position of B11 and B13 and the upward peak thereof). It is judged that the amplitude of the downward peak (the height difference between the reference positions of B11 and B13 and the upward peak immediately before it) is larger than the amplitude of the downward peak (the height difference between the downward peaks immediately before). The peak α'in the direction is set as the reference peak. In waveforms B12 and B14, the amplitude of the peak above the amplitude of the downward peak (the height difference between the reference position of B12 and B14 and the downward peak immediately after the reference position) (at the reference position of B12 and B14). It is judged that the height difference between the immediately preceding downward peak and the reference position) is larger, and the upward peak α is set as the reference peak. Therefore, the reference position is detected alternately in the upward direction and the downward direction.

On the other hand, in this embodiment, the peak in one direction is preferentially detected, and in FIG. 7B, assuming that the upward direction is preferentially detected when B21 is detected, the waveforms B21, B22, and B23 In and B24, since the height difference is corrected at the time of comparison so as to make it easier to detect the upward direction, all the peaks α in the upward direction can be set as the reference peak (reference position).

As described above, in the cases of FIGS. 6 and 7, by using this embodiment, the protruding direction of the reference peak can be made constant even if the waveform shape of the electrocardiogram signal changes. As long as the protruding direction of the reference peak is kept constant, an error of several tens of ms, which is mixed when the protruding direction of the reference peak changes, is not mixed, so that the error of the heartbeat interval due to this cause can be eliminated.

Therefore, in the applied research of the heartbeat interval as mentioned in the background technique of the present invention, while the reference peak in the priority direction is continuously detected by using this embodiment (while the protrusion direction of the reference peak is constant). Can eliminate the misjudgment caused by the change in the waveform shape.

Although this embodiment is configured as described above, it may be configured as shown in FIGS. 8 and 9.

That is, when the heartbeat interval is measured after wireless transmission, the data to be wirelessly transmitted increases. When the amount of data to be transmitted wirelessly increases, a large amount of power is required for transmission, and power saving cannot be achieved. If power saving cannot be achieved, it is necessary to increase the size of the battery, which makes it difficult to miniaturize the biometric information measuring device. However, when a communication means capable of saving power even if a large amount of data is wirelessly transmitted appears, the electrode 2, the signal processing means 1, and the heartbeat interval measuring means 3 are shown as in another example 1 shown in FIG. Etc. may be provided in a separate device, and the wireless transmitting means 6 and the wireless receiving means 7 for transmitting and receiving digital electrocardiogram signals may be provided in each device to measure the heartbeat interval after wireless transmission. In this case, since it is not necessary to wear the wireless receiving means or later, there are advantages such as easy maintenance of the measuring instrument to be worn and easy change of the means after the wireless receiving means.

In addition, when measuring the heartbeat interval after data storage, the power for storing the data and the capacity for storing the data increase, so that power saving cannot be achieved and the size is reduced as in the case after wireless transmission. Is difficult. However, if a storage means capable of saving power even if a large amount of data is stored appears, the electrode 2, the signal processing means 1, the heartbeat interval measuring means 3, etc., as shown in another example 2 shown in FIG. And are provided in a separate device, and the data storage means 8 and the data reading means 9 for storing and reading the digital electrocardiogram signal are provided in each device, and the heartbeat interval is measured after the data is stored. good. In this case as well, as in the case of FIG. 8, since it is not necessary to wear it after the data reading means, there are advantages such as easy maintenance of the measuring instrument to be worn and easy change of the means after the data reading means. There is.

Since this embodiment is configured as described above, the reference peak of the QRS wave (the peak of the R wave, the S wave, or the Q wave) of one beat of the digital electrocardiogram signal and the reference peak of another QRS wave (the peak of the Q wave) adjacent to the reference peak (R wave, S wave, or Q wave peak). When measuring the heartbeat interval from the distance from the R wave, S wave, or Q wave apex), the heartbeat interval measuring means 3 measures the heartbeat interval and also acquires the protruding direction information of each reference peak, and this protruding direction information. By determining the priority direction based on the above and making it easier to continuously set the peak in the priority direction as the reference peak even if the peak amplitude fluctuates, the change in the reference peak is suppressed and the fluctuation in the heartbeat interval also It will be suppressed, and it will be possible to measure the heartbeat interval with a smaller error.

Therefore, this embodiment is a practical biometric information measuring device capable of measuring a heartbeat interval with as little error as possible.

1 Signal processing means 3 Heart rate interval measuring means 4 Priority direction determining means

Claims (7)

Biological information measurement capable of measuring the heartbeat interval of a living body having a signal processing means for digitizing an analog electrocardiogram signal including a QRS wave to create a digital electrocardiogram signal and a heartbeat interval measuring means for measuring the heartbeat interval from the digital electrocardiogram signal. It ’s a device,
The heartbeat interval measuring means sets one peak in the QRS complex for one beat as a reference peak, measures the heartbeat interval from the interval between the reference peaks of the QRS complex for each beat, and measures the heartbeat interval. It is configured to acquire protrusion direction information indicating whether each reference peak protrudes upward or downward.
There is a priority direction determining means for determining whether to preferentially set a peak projecting upward or downward in the QRS complex as the reference peak based on the past one or a plurality of the projecting direction information. However, this priority direction determining means determines the direction in which the number of occurrences is large in the predetermined number of past protrusion direction information as the priority direction.
The biological information measurement means is configured to preferentially set a peak in a priority direction determined by the priority direction determining means to the reference peak in each QRS complex. Device. In the biometric information measuring device according to claim 1, the heartbeat interval measuring means compares the height difference of each peak in the QRS complex for one beat and sets the peak having the largest height difference as a reference peak. A biological information measuring device characterized by being configured. In the biometric information measuring device according to claim 2, when comparing the height difference of each peak in the QRS complex, the peak in the priority direction determined by the priority direction determining means can be easily set as the reference peak. , A biological information measuring device comprising a height difference correction means for correcting and comparing the height difference of the peak. The biometric information measuring device according to any one of claims 1 to 3, wherein the signal processing means includes a filter means for performing filtering processing. The biometric information measuring device according to any one of claims 1 to 4, wherein the priority direction determining means is in a neutral state in which the priority direction is not determined at the time of non-measurement. In the biometric information measuring device according to any one of claims 1 to 5, the priority direction determining means determines the upward direction as the priority direction when the number of appearances is the same in a predetermined number of past protruding direction information. A biological information measuring device characterized by In the biometric information measuring apparatus according to any one of claims 1 to 6 , when a peak that is not the priority direction determined by the priority direction determining means is continuously set to the reference peak a predetermined number of times, the priority direction A biological information measuring device characterized in that the determining means is configured to be in a neutral state in which the priority direction is not determined.

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