JP2020174690A - Biological signal processing device - Google Patents

Abstract

To provide a biological signal processing device capable of acquiring stable vital information in a life and exercise or even in a situation in which there is movement of a body and a change of an environment.SOLUTION: A biological signal processing device includes: an ECG measuring unit 110 for acquiring an electrocardiographic signal from a body surface of a living body; an R wave extraction unit 120 for extracting an R wave included in the electrocardiographic signal from characteristics, and specifying a position of an R wave peak; an SNR calculation unit 130 for calculating an SNR (signal to noise ratio) in an R wave section specified by the R wave extraction unit; and an RRI output unit 140 for obtaining an R wave interval from the position of the R wave peak and the SNR in the R wave section, and outputting it. Data in a period when the determination at the SNR calculation unit is NG is not used.SELECTED DRAWING: Figure 1

Description

The present invention relates to a biological signal processing device, and more specifically, to a biological signal processing device capable of acquiring a stable vital signal even during exercise or changes in the environment.

Many techniques for measuring biological signals have been proposed so far, and as an example, Patent Document 1 includes a biological information detection unit that detects the biological information of the user and a user who determines the motor ability of the user. A judgment unit, an information setting unit that sets analysis information according to the user's motor ability when it is determined that the user's motor ability satisfies a predetermined condition, and an information setting unit that analyzes biological information based on the set analysis information. A biometric information analysis device has been proposed, which is provided with an analysis unit that can appropriately measure biometric information even for a user having a sports heart.

Patent Document 2 includes a biological information detection unit that detects biological information about a subject and a body movement information detection unit that detects body movement information related to the movement of the subject in order to improve the accuracy of the pulse rate estimated from exercise intensity. , Update the reliability determination unit that determines the reliability of the biological information based on a predetermined standard, the storage unit that stores the correlation between the body movement information and the biological information, and the correlation stored by the storage unit. When the reliability determination unit determines that the biological information satisfies the predetermined criteria, the updating unit updates the correlation based on the biological information and the body movement information. The information processing device is described.

In Patent Document 3, the first step of estimating the respiratory rate of a subject from each of the time-series signal of the first data regarding the cardiac function of the subject and the time-series signal of the second data regarding the acceleration due to the respiratory movement of the subject. And, in the second step of estimating the respiratory rate estimated from the first data and the respiratory rate estimated from the second data by the Kalmanf filter, respectively, and in this second step. A respiratory rate estimation method is described that includes a third step of performing a weighted averaging process for the obtained plurality of respiratory rate estimates.

Further, Patent Document 4 describes an electrocardiogram measurement electrode for measuring an electrocardiogram, a noise measurement electrode for measuring noise, an electrocardiogram signal measured by the electrocardiogram measurement electrode, and a noise signal measured by the noise measurement electrode. An electrocardiogram that is equipped with a measuring unit for measurement and a thoracic compression noise removal processing unit that extracts a noise-removed electrocardiogram that removes noise by analyzing the measured electrocardiogram signal and noise signal, and reduces the influence of noise due to thoracic compression. An analyzer and electrode set are described.

International Publication No. 2016/08A307 International Publication 2014/196119 International Publication No. 2017/090732 Japanese Unexamined Patent Publication No. 2014-076117

The measurement (detection) of biological information is performed not only in the resting state but also during work and exercise, but the objects of the prior art mentioned above are mainly pulse waves and respiratory rates, and also by electrocardiography. Even if there is, it is the influence of body movement in AED, and the large changes in the environment associated with strenuous exercise, exercise, and work are not taken into consideration.

Therefore, an object of the present invention is to enable stable vital information to be acquired in daily life and exercise, and also in the presence of changes in body movements and environment.

In order to solve the above problems, the present invention has some characteristic configurations. First, the first invention specifies an ECG measuring unit that acquires an electrocardiographic signal from the body surface of a living body, extracts an R wave contained in the electrocardiographic signal from its characteristics, and specifies the position of an R wave peak. The R wave extraction unit, the SNR calculation unit that calculates the SNR (signal-to-noise ratio) of the R wave section specified by the R wave extraction unit, the position of the R wave peak, and the SNR to R of the R wave section. It is characterized by having an output unit that obtains and outputs a wave interval.

In the first invention, the signal amount for calculating the SNR in the SNR calculation unit is calculated by aligning and averaging the positions of each R wave using the R wave time extracted by the R wave extraction unit. To calculate the SNR by the signal calculation unit, the wave removal unit that removes the original electrocardiographic signal such as PQRST from the noisy electrocardiographic signal measured by the ECG measurement unit, and the SNR calculation unit. A noise calculation unit that obtains the amount of noise from the noise waveform extracted by the wave removal unit, an SNR comparison unit that compares the SNR calculated by the SNR calculation unit with a predetermined threshold value in each section of the R wave, and a frequency. The output unit further includes an analysis unit, and the output unit calculates the RRI by taking the difference between the times of two consecutive R wave peaks in the section excluding the section where SNR <threshold in the SNR comparison unit. The mode of outputting the result and calculating and outputting the fluctuation of RRI is included in the frequency analysis unit.

In the first invention, the frequency analysis unit is characterized in that it uses RRI with an indefinite interval to perform frequency analysis based on the least squares method of a sine wave.

In the second invention, the ECG measuring unit processes signals from a plurality of ECG electrodes, compares the SNR calculated by the SNR calculating unit between the ECG electrodes, and selects the best SNR. The SNR / inter-electrode comparison section is compared with the best SNR / threshold value selected by the SNR / inter-electrode comparison section, and the comparison result is given to the output section. Further equipped with a part.

Preferably, each section of the raw waveform of each ECG electrode measured by the ECG measuring unit is multiplied by the SNR of the section calculated by the SNR calculating unit, and the polarity of each ECG electrode is determined. A weight synthesizing unit to be added and an R wave re-extracting unit that re-extracts the R wave from the synthesized wave synthesized by the weight synthesizing unit and gives it to the output unit are further provided.

The third invention further includes a case as a storage container having a signal processing circuit including the ECG measurement unit, the R wave extraction unit, the SNR calculation unit, and the output unit inside, and the plurality of ECG electrodes. A part of the ECG electrode is electrically connected to the ECG measurement unit via a terminal provided on the upper part of the case, and the rest of the plurality of ECG electrodes are arranged on the bottom surface of the case and via a routing wire in the case. It is characterized in that it is connected to the ECG measuring unit.

In the third invention, preferably, a heat flow measuring unit having a plurality of thermometers for measuring the heat flow flowing between the inside of the living body and the environment is provided in the case.

Further, in the third invention, the bottom surface of the case is closed by an insulating sheet, and ECG electrodes divided into two are arranged on the outer surface side of the insulating sheet at predetermined intervals, and the above is described. The thermometer is arranged at a portion located between the two ECG electrodes on the inner surface side of the insulating sheet, and the electrode surface of each ECG electrode and the sheet surface of the insulating sheet between them are on the same plane. It is characterized by being present in.

Further, according to the preferred embodiment of the third invention, the portion where the ECG electrode is arranged on the outer surface side of the insulating sheet is formed as thin as the thickness of the ECG electrode.

The fourth invention is characterized in that it has a garment to be worn on the upper body of a living body, and a predetermined portion of the garment is provided with an ECG electrode and a heat flow pad for measuring a heat flow flowing between the living body and the environment. It is said.

In the fourth invention, the heat flow pad includes a heat flow measuring means including a heat insulating material and two thermometers arranged on an upper surface and a lower surface thereof.

Further, in the fourth invention, the ECG electrodes are provided at a portion of the clothing corresponding to a region where the positive electrocardiographic potential is prominent and a portion corresponding to a region where the negative electrocardiographic potential is prominent. Has been done.

The fourth invention includes an embodiment in which a spring material for maintaining contact between the ECG electrode and the skin is arranged between the fabric of the clothing and the ECG electrode.

Further, it is preferable that a spring material for maintaining contact between the thermometer on the lower surface side and the skin is also arranged between the fabric of the clothing and the heat insulating material.

As the heat insulating material, a gas mat containing a plurality of bubbles arranged on a flat surface is preferably used.

Further, in the fourth invention, the heat flow pad is provided with two heat flow measuring means, and the gas mat is for the first gas mat for one of the heat flow measuring means and the other heat flow measuring means. The first gas mat and the second gas mat are divided into the second gas mat, and the second gas mat includes a mode in which gases having different thermal conductivitys are sealed.

A fifth invention includes a heat flow measuring unit that measures the heat flow flowing between the inside of the living body and the environment, a deep temperature calculating unit that calculates the deep temperature of the living body based on the temperature information from the heat flow measuring unit, and the deep portion. A noise calculation unit that calculates the noise contained in the temperature, and an output unit that calculates and outputs a new deep temperature from the noise calculated by the noise calculation unit and the deep temperature calculated by the deep temperature calculation unit. It is characterized by having.

Further, the fifth invention is characterized in that the noise is obtained from the output of a high-pass filter having a deep temperature input.

In another aspect, the fifth invention is measured by a heat flow measuring unit that measures the heat flow flowing between the inside of the living body and the environment, an environmental temperature measuring unit that measures the environmental temperature, and the environmental temperature measuring unit. A false signal generation unit that creates a false signal from the ambient temperature, a deep temperature calculation unit that calculates the deep temperature of the living body from the heat flow measured by the heat flow measurement unit, a false signal generated by the false signal generation unit, and the above. It is characterized by having an output unit that calculates and outputs a new deep temperature from the deep temperature calculated by the deep temperature calculation unit.

Further, the sixth invention is an ECG measuring unit that acquires an electrocardiographic signal from the body surface of a living body, a heat flow measuring unit that measures a heat flow flowing between the inside of the living body and the environment, and an acceleration measurement unit that measures the acceleration of the living body. The unit, the environment measurement unit that measures the environmental condition surrounding the living body, the ECG-SNR comparison unit that calculates the signal-to-noise ratio of the electrocardiographic signal and compares it with a predetermined first threshold value, and the heat flow measurement unit. A deep temperature-noise comparison unit that calculates the noise contained in the measured heat flow and compares it with a predetermined second threshold value, an acceleration measured by the acceleration measurement unit, and an environment measurement unit that measures the acceleration. The comparison result from the threshold generation unit that changes the first threshold value and / or the second threshold value from the environmental condition, the ECG-SNR comparison unit, and the deep temperature-noise comparison unit is also obtained. It is characterized by having an output unit that outputs a notification signal.

According to the present invention, it is possible to acquire stable vital information in daily life and exercise, and also in the presence of changes in body movements and environment.

The schematic diagram which shows the basic structure of 1st Embodiment of this invention. The schematic diagram which shows the specific structure of the said 1st Embodiment. A waveform diagram showing an example of an electrocardiographic waveform measured by an ECG measuring unit. The waveform diagram for demonstrating the signal processing example in the R wave extraction part. The waveform diagram for demonstrating the example of signal processing in a signal calculation part. (A)-(d) Waveform diagram for explaining an example of signal processing in a wave removing section. The waveform diagram for demonstrating the example of signal processing in a noise calculation part. The waveform diagram for demonstrating the signal processing example in the SNR calculation part. The schematic diagram for demonstrating the signal processing example in the SNR comparison part, the output part and the frequency analysis part. The schematic diagram which shows the 1st aspect of the 2nd Embodiment of this invention. The schematic diagram for demonstrating the operation of the 1st aspect. The wave system diagram for demonstrating the details of the SNR comparison means in the 1st aspect. The schematic diagram which shows the 2nd aspect of the 2nd Embodiment of this invention. The schematic diagram for demonstrating the operation of the 2nd aspect. A schematic perspective view (a) and an arrow view A (bottom view) of (b) and (a) showing a first aspect of a sensor structure having a plurality of ECG electrodes according to a third embodiment of the present invention. A schematic perspective view (a) and a B arrow view (bottom view) of (b) and (a) showing a second aspect of the sensor structure. The schematic perspective view which shows the 3rd aspect of the said sensor structure. (A) Schematic perspective view, (b) (a) C arrow view (side view), (c) (a) showing a fourth aspect having a core body temperature measurement function of the above sensor structure. D arrow view (bottom view). A schematic exploded perspective view showing a first example of a case applied to the fourth aspect. The schematic exploded perspective view which shows the 2nd example of the case applied to the said 4th aspect. FIG. 6 is a schematic exploded perspective view showing a third example of the case applied to the fourth aspect. A schematic view showing (a) a front surface and (b) a schematic view showing a back surface of a garment having an ECG electrode and a heat flow pad for heat flow detection according to a fourth embodiment of the present invention. (A) A schematic plan view, (b) a perspective view, and (c) (b) a schematic cross-sectional view taken along the line EE showing the wiring on the garment. (A) plan view and (b) (a) schematic cross-sectional view along the FF line showing the ECG electrode pad provided on the wear. A plan view similar to (a) FIG. 16 (a) and a schematic cross-sectional view taken along the line GG of (b) and (a) showing an ECG electrode pad provided on the wear. (A) plan view and (b) (a) schematic cross-sectional view along the HH line showing the SHF type heat flow pad provided on the wear. A plan view similar to (a) FIG. 18 (a) and a schematic cross-sectional view taken along line I-I of (b) and (a) showing an SHF type heat flow pad provided on the wear. A plan view (a) and a schematic cross-sectional view taken along the line JJ of (b) and (a) showing a DHF type heat flow pad provided on the wear. A plan view similar to (a) FIG. 20 (a) and a schematic cross-sectional view taken along the line KK of (b) and (a) showing a DHF type heat flow pad provided on the wear. A schematic perspective view showing (a) a first example, (b) a schematic perspective view showing a second example, and (c) a schematic perspective view showing a third example of the heat insulating material applied to the heat flow pad. Figure. The schematic diagram which shows the 1st aspect which concerns on 5th Embodiment of this invention. The schematic diagram which shows the 2nd aspect of the said 5th Embodiment. The schematic diagram for demonstrating the operation of the 2nd aspect. The schematic diagram which shows the 3rd aspect of the said 5th Embodiment. The schematic diagram for explaining the operation of the said 3rd aspect. The schematic diagram which shows the 4th aspect of the said 5th Embodiment. The schematic diagram for demonstrating the operation of the 4th aspect. The schematic diagram which shows the 5th aspect of the said 5th Embodiment. The schematic diagram which shows the 6th aspect of the said 5th Embodiment. The schematic diagram for demonstrating the operation of the 6th aspect. The schematic diagram which shows the basic structure of 6th Embodiment of this invention. The schematic diagram which shows the specific structure of the said 6th Embodiment.

Next, some embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

[First Embodiment] Calculation of SNR of ECG wave and its use As shown in FIG. 1, the biological signal processing apparatus according to the first embodiment has, as a basic configuration, an ECG measurement unit 110 and an R wave extraction unit. It includes 120, an SNR calculation unit 130, and an output unit (RRI output unit) 140.

Briefly explaining the role of each part, the ECG (Electrocardiography) measuring unit 110 measures (acquires) an electrocardiographic signal from the body surface. The R wave extraction unit 120 extracts the R wave included in the electrocardiographic signal from its characteristics and identifies the position of the R wave peak.

The SNR calculation unit 130 calculates the signal-to-noise ratio (SNR) of the electrocardiographic signal. As the signal, the amplitude from the minimum to the maximum of the electrocardiographic signal can be used, or the effective value can be used. Noise is a component other than thermal power caused by the beating of the heart in the acquired electrocardiographic signal, and is caused by movement or movement, such as electrode-skin displacement or contact change, contact potential change, static electricity, sweat, etc. This is due to changes in conductance due to the above, myoelectricity, induction from AC power supply, etc.

The output unit (RRI output unit) 140 outputs a signal process based on the SNR obtained by the SNR calculation unit 130 to the R wave and the surrounding section obtained by the R wave extraction unit 120. As the signal processing, for example, heart rate, heart rate fluctuation (HRV, Heart Rate Variability), shape of PQRST wave, biological information (vital information) required from them can be displayed or notified, and other programs can be used. To.

Next, as shown in FIG. 2, this biometric signal processing device has, as a specific configuration, in addition to the ECG measurement unit 110, the R wave extraction unit 120, the SNR calculation unit 130, and the output unit (RRI output unit) 140. , A signal calculation unit 121, a wave removal unit 122, a noise calculation unit 123, an SNR comparison unit 131, and a frequency analysis unit 150 are provided.

Explaining the operation of each unit in more detail, the ECG measuring unit 110 amplifies the signal from the electrocardiographic detection electrode (ECG electrode) attached to the body surface, filters it appropriately, and outputs the signal (see FIG. 3a). The filter includes a high-pass filter (HPF) and a low-pass filter (LPF).

The high-pass filter removes the fluctuation of the baseline of the electrocardiographic signal. The low-pass filter removes inductive noise from the AC power line and myoelectric noise due to the movement of the chest muscles. The pass band determined by the high-pass filter or low-pass filter is usually set to pass from several Hz to 40 Hz, and in a noisy environment, to pass from about 10 Hz to 20 Hz.

Narrowing the passband enhances the noise suppression effect, but deteriorates the reproducibility of the original electrocardiographic signal emitted when the heart beats. In addition, due to exercise or movement in daily life, noise may enter the narrowed band and cannot be completely removed.

One of the factors that generate noise due to exercise is the contact potential generated between the ECG electrode and the skin. By using silver / silver chloride (Ag / Agcl) as the electrode material, the contact potential can be lowered, but it is difficult to make it zero.

If the contact between the ECG electrode and the skin is displaced or the contact area is changed due to the movement, this finite potential changes and becomes noise. Impulse-like potential changes have a wide spectrum and enter the passband.

Since the belt or wear for fixing the ECG electrode to the body usually uses fibers, it is difficult to eliminate the generation of static electricity. Static electricity also generates impulse-like potentials, causing similar problems.

When a living body sweats due to exercise, a layer of sweat may be formed on the skin surface, or it may be absorbed by a belt or clothing and have a conductivity of about 0.1 mS (resistivity of about 10 kΩ). Changes in this conductivity due to movement also cause similar problems.

These phenomena are random processes that change depending on the motion vector, the position where the ECG electrode is attached, the degree of adhesion to the skin, etc., and as shown in FIG. 3a, as noise (artifact) in a specific section. appear.

Here, as the definition of the section, the time domain for each R wave is defined as a division between the peak time of one R wave and the peak time of the next R wave. As shown in FIG. 3a, there are sections with less noise and sections with more noise.

Next, referring to FIG. 3b, the R wave extraction unit 120 extracts the R wave. As a method of extracting the R wave, for example, there is a method of setting a threshold value for the amplitude of the QRS wave and identifying the value above the threshold value as the QRS wave. Alternatively, thresholds can be set for features such as the slope and length of the waveform.

Further, since the electrocardiographic signal is a repetition of waveforms having substantially the same shape, the position of the R wave can be specified by using an autocorrelation function, template matching, a wavelet, or the like.

Many methods are known for these R wave extractions, but there is a limit in noise having a shape similar to the original electrocardiographic signal or when the original electrocardiographic signal is buried in the noise. Further, by applying the features of the present invention such as selecting the R wave section by SNR and selecting and synthesizing a good signal from a plurality of electrodes while using these conventional R wave detection methods. You can also get more effective output.

With reference to FIG. 3c, the signal calculation unit 121 calculates the signal amount for SNR calculation. As described above, the amplitude of the electrocardiographic signal from the minimum to the maximum can be used as the signal, or the effective value can be used.

For example, by using the R wave time extracted by the R wave extraction unit 120 and averaging the positions of each R wave, it is possible to calculate the signal amount with less noise. A moving average can also be used as the averaging method. Since the QRS complex is usually the maximum amplitude of the original electrocardiographic signal, the peak-to-peak of the QRS complex can also be used as the signal amplitude.

In some cases, the signal quality can be determined using only noise without performing signal calculation by the signal calculation unit 121, but in the case of ECG, there are individual differences in amplitude or differences in the mounting position of the ECG electrode. Since there may be a difference in amplitude and the gain of the amplifier may be automatically adjusted by AGC (Auto Gain Control), it is preferable that the signal calculation unit 121 calculates the signal.

With reference to FIG. 3d, the wave removing unit 122 removes waves such as PQRST included in the original electrocardiographic signal (electrocardiographic waveform). In this example, as shown in FIG. 3d (a), the period of the QRS complex and the period of the T wave are removed. The period of other waves such as P wave and U wave can be removed, but these P wave and U wave often do not have a great influence on the calculation of the amount of noise, so leave them as they are. May be good.

The upper part of FIG. 3d (b) shows the actual electrocardiographic waveform before removing the PQRST wave, and the lower part shows the waveform after removing the PQRST wave. The peak positions of the R waves are aligned and the sections of about 100 are overlapped. Since the acquisition is in a stationary state, the amount of noise is small, and the amplitude is about -8 to +6 LSB, and the effective value is about 3 LS Brms. By the way, the amplitude of the QRS wave is about 350 LSB in this example, and the signal-to-noise ratio (SNR) is 100 or more (signal amplitude-to-noise effective value).

FIG. 3d (c) shows an example acquired during exercise, the upper row shows the actual electrocardiographic waveform before the PQRST wave is removed, and the lower row shows the waveform after the PQRST wave is removed. The peak positions of the R waves are aligned and the sections of about 100 are overlapped. The amount of noise is an amplitude of about −600 to +600 LSB, and an effective value is about 100 LS Brms. Since the signal is about 300 LSB, the SNR is about 3.

As another example of wave removal, as shown in FIG. 3d (d), a moving average is obtained by aligning the positions of the R waves in each section, and the moving average is subtracted from the electrocardiographic signal containing noise. Often, such aspects are also included in the present invention.

Next, with reference to FIG. 3e, the noise calculation unit 123 obtains, for example, an effective value of the noise waveform extracted as described above as a noise amount. The amplitude of noise can also be used as the amount of noise. When the noise amount in each section is, for example, the noise amount Ni in the latest section, the noise amount in the previous section is Ni-1, and the noise amount in the previous section is Ni-2, ... The amount of noise Ni in the section of is sequentially obtained, and is added after the previous section Ni-1.

The SNR calculation unit 130 calculates the SNR from the signal amount and the noise amount. As the signal amount, the moving average or the instantaneous value of each section can be used, and as the noise amount, the effective value of each section can be used. An example of the SNR obtained in this way is shown in FIG. 3f. The heart rate is also included for reference. The part with low heart rate in the first half is sitting (when sitting), and the part with high heart rate in the second half is exercising on an exercise bike (registered trademark) (during exercise). ..

When the SNR decreases to about 20 or less, the frequency of erroneous (false detection) extraction of the R wave itself increases, such as the extraction time of the R wave shifting or noise being extracted as the R wave. There is a possibility that a detection omission that cannot extract the original R wave may occur.

In the first half of the sitting position, although the SNR fluctuates, it is about 30 or more, and the frequency of false detections and omissions is low. During the latter half of the exercise, the SNR becomes 20 or less at a high frequency, and false detection or detection omission occurs at a high frequency. False detections and omissions not only deteriorate the accuracy of heart rate calculation, but also deteriorate the accuracy of HRV obtained by using the R wave interval (RRI: RR Interval). In some cases, it may not be possible to output heart rate or HRV.

The SNR for each section fluctuates greatly. Even in the sitting position in the first half, there are sections in which the body is completely stationary and sections in which the body is not completely stationary, so the SNR varies from 200 or more to several tens of SNRs. Even during the latter half of the exercise, while constantly rowing an exercise bike (registered trademark), there are sections where the SNR is very bad and sections where the SNR is good to some extent.

The length of the section (RR interval) varies depending on the heart rate, but is about 0.3 to 1 second. The exercise bike (registered trademark) exercise becomes a one-second cycle exercise when the pedal is turned at 60 rpm, for example. If there is a time during which the ECG electrode does not generate an artifact, for example, about 0.5 seconds in the motion vector change with a cycle of 1 second, there is a section having a high SNR.

With reference to FIG. 3g, the SNR comparison unit 131 compares the SNR with the threshold value in each section. As the threshold value, for example, a value of 20 or less, which is the SNR at which the above-mentioned false detection occurs, can be used.

Due to the decrease in the interval SNR, the electrocardiographic features cannot be extracted and detection omissions occur, but the original detection omissions are a problem of feature extraction and are not related to the threshold value. Setting a higher threshold to reduce false positives increases the risk of causing the problem of deleting normally detected sections (missing detection due to threshold).

The probability of occurrence of detection omission due to the threshold value increases from about 10 SNRs that can detect R waves to some extent. In the sense that normal detection is not discarded, the threshold value is preferably about 10 or less.

When the comparison result of SNR is the latest section Ri and the previous one is Ri-1, the latest section Ri is obtained and added to the results before Ri-1 in sequence. Then, if it is above the threshold value, it is judged as OK, and if it is below the threshold value, it is judged as NG.

The RRI output unit 140 outputs the calculation result of RRI. RRI is calculated by taking the time difference between two consecutive R wave peaks. At this time, the period during which the determination by the SNR comparison unit 131 is NG is not used.

For example, when the section Ri-2 is NG, the R wave extraction result in the section i-2 is not used. That is, it means that the RRI is not calculated between the interval i-1 and the interval i-2, and further between the interval i-2 and the interval i-3.

The section that became NG often includes the detection omission of the R wave, and it is also an error to jump over the section i-2 and calculate the RRI between the section i-1 and the section i-3. In many cases, this calculation is not performed either.

The frequency analysis unit 150 calculates and outputs the fluctuation of RRI, that is, HRV. There is a conventional example in which RRI is subjected to spline interpolation and resampled at regular time intervals, but if spline interpolation is applied to RRI including omissions, false vibration may occur, which is not preferable.

It is preferable to perform frequency analysis based on the least squares method of sine waves using RRI at indefinite intervals without performing spline interpolation or resampling. As such a frequency analysis, there is, for example, a Lomb-Scargle periodogram.

In addition, by aligning the peak positions of the R waves and averaging the raw ECG waveforms in the sections with high SNR, it is possible to obtain a waveform that is faithful to the original ECG waveform with little error due to noise. .. Averaging with ECG waves disturbed by moving artifacts causes large errors in the wave information.

The peak value and slope of the PQRSTU wave and the like reflect the characteristics of the living body, autonomic nerves and hormones, blood oxygen concentration, potassium concentration, and other substance concentrations. For example, in an experiment simulating high-altitude mountain climbing, it has been reported that the ST wave changes due to a decrease in blood oxygen concentration. By accurately obtaining the wave information of ECG, it is possible to grasp the state of such a living body.

[Second Embodiment] Synthesis of a plurality of electrode signals using the SNR of ECG The second embodiment includes a first aspect shown in FIG. 4 and a second aspect shown in FIG. 7, both of which are plural. It has ECG electrodes 1, 2, ...

-First aspect-
First, the first aspect will be described. In addition to the ECG measurement unit 210, the R wave extraction unit 220, and the SNR calculation unit 230, the SNR / electrode-to-electrode comparison unit 231, the SNR / threshold value comparison unit 232, and the RRI output unit 240 And a frequency analysis unit 250 is provided.

Of these, the ECG measurement unit 210, the R wave extraction unit 220, the SNR calculation unit 230, the RRI output unit 240, and the frequency analysis unit 250 are the ECG measurement unit 110 and the R wave extraction unit described in the first embodiment, respectively. It may have the same configuration as the 120, the SNR calculation unit 130, the RRI output unit 140, and the frequency analysis unit 150.

The ECG electrodes 1, 2, ... Are attached to the skin of a living body in order to detect an electrocardiogram. As the electrode material, Ag / AgCl, Ag, and a conductive plastic having a small contact potential are preferably adopted.

Artifacts are superimposed on the original electrocardiographic signal according to the motion vector, the place where the ECG electrode is attached, the movement of the muscle, the degree of adhesion to the skin, and the like. Multiple ECGs are used because the muscles and vectors used differ depending on the content of the exercise (for example, from basic training such as abdominal muscles, push-ups, running, training using machines, competitive sports, stretching with free movement, yoga, dance, etc.) The way in which artifacts enter differs between the electrodes.

The ECG measurement unit 210 may be provided for each ECG electrode, but can be integrated into one by switching the high-resolution ADC (analog-digital converter) by time division (interleave).

By synthesizing the signals from the plurality of ECG electrodes 1, 2, ... According to the SNR, the influence of the artifact can be suppressed. The electrocardiographic signal can be increased by synchronously adding (adding by aligning the positions) the original electrocardiographic signals.

Since the ECG signal is unknown, it is difficult to completely separate the ECG from the artifact. However, since the artifact is generated by the mechanism described above, it has a waveform and spectrum different from the original electrocardiographic signal (PQRST wave).

Most of them are band-limited waves in which the impulse-like and step-function-like changes in the contact potential due to the impact of motion are band-limited, and are different from the original electrocardiographic signal. The SNR calculation unit 230 quantifies the wave energy of the artifact spreading in each section.

The R wave extraction unit 220 and the block following the R wave extraction unit 220 may have the same configuration as that of the first embodiment, but can be integrated into one system by switching the processing electrodes at regular intervals.

The SNR calculation unit 230 calculates the SNR at each ECG electrode 1, 2, ... At each time, and obtains a time series of the interval SNR as shown in FIG. 5 for each ECG electrode 1, 2, .... In FIG. 5, SNR1, i-2: SNR1, i-1: SNR1, i are the time series of the section SNR of the ECG electrode 1, and SNR2, i-2: SNR2, i-1: SNR2, i are the ECG electrodes. It is a time series of the interval SNR of 2.

The SNR-electrode comparison unit 231 compares the SNR of each ECG electrode at each time and selects the best SNR.

The SNR / threshold value comparison unit 232 compares the selected SNR with the threshold value, and outputs the R wave time extracted by the ECG electrode having the best SNR at each time if it is equal to or higher than the threshold value. If it is less than the threshold value, a blank is output. In FIG. 5, Ri, Ri-1, Ri-2 ... Are the above outputs stored in a memory or the like.

The RRI output unit 240 calculates and outputs the R wave interval (RR Interval) based on the stored R wave time. Similar to the first embodiment, the blank means less than the threshold value, so the RRI before and after the blank is not calculated.

The frequency analysis unit 250 uses the RRI to perform frequency analysis at irregular intervals based on the least squares approximation of the sine wave, similar to the first embodiment.

The details of the SNR / threshold value comparison unit 232 will be described with reference to FIG.

FIG. 6A is an example of a relatively simple case, and it is assumed that the ECG electrode 1 and the ECG electrode 2 have the same section switching timing, and that the section i-2 of the ECG electrode 1 contains an artifact.

The SNR-electrode comparison unit 31a determines that the SNR is ECG electrode 1 <ECG electrode 2. Further, if the ECG electrode 2 is equal to or higher than the threshold value, the ECG electrode 2 is selected by the SNR / threshold value comparison unit 31b, and the R wave time is adopted (if it is equal to or lower than the threshold value, both are adopted. Not adopted). That is, as follows.

(1) When the threshold value <SNR1, i-2 <SNR2, i-2, the R wave time extracted by the ECG electrode 2 is adopted.
(2) When SNR1, i-2 <threshold value <SNR2, i-2, the R wave time extracted by the ECG electrode 2 is adopted.
(3) When SNR1, i-2 <SNR2, i-2 <threshold value, neither is adopted.

FIG. 6B is an example in which the length of the section differs between the ECG electrode 1 and the ECG electrode 2 in a slightly complicated case. In the ECG electrode 1, the artifacts are extracted as R waves in the intervals i-2 and i-1. The section i-2 of the ECG electrode 2 correctly detects the original R wave, but straddles the sections i-2 and i-1 of the ECG electrode 1.

In general, the QRS period is the most important period for feature extraction of ECG, and it is good to pay attention to this narrow period. By narrowing it, the number of comparison partners may be narrowed down to one, but as in this example, it may still be two. In this case, the following processing should be performed.

That is, when SNR1, i-2 <SNR1, i-1 <SNR2, i-2, SNR2, i-2 is adopted. The reason is that the SNR is lowered in both sections of the ECG electrode 1.

Other than the above, SNR2 and i-2 are not adopted. The reason is that the ECG electrode 1 has an extract with a high SNR, and the ECG electrode 2 may have an artifact.

-Second aspect-
As shown in FIG. 7, in order to perform weighted synthesis according to SNR, the weight synthesis section 233 and R are replaced with the SNR / electrode comparison section 231 and the SNR / threshold comparison section 232 in the first aspect. A wave re-extraction unit 234 is provided. The other configuration is the same as the first aspect. FIG. 8 shows a schematic diagram for explaining the operation of each part.

The weight synthesizing unit 233 multiplies the ECG raw waveforms of the ECG electrodes 1, 2, ... For each time by the SNR of the section. For example, it is assumed that the ECG raw waveform of the ECG electrode 1 is divided into the sections v1, i: v1, i-1: v1, i-2, ... By the R wave provisional detection.

The length of each section is determined by the RR interval as described above, and is, for example, about 0.3 to 1 second. For example, assuming that the sampling rate of the ADC is 128 sps, each section contains 38 to 128 time series data (x1, x2, ...).

That is, each section is a set of the above time series data, and for example, the sections v1, i = {x1, x2, ...}. Multiplying this by SNR gives SNR1, i × v1, i = {SNR1, i × x1, SNR1, i × x2, ...}.

Further, the weight synthesizing unit 233 adds the polarities of the ECG electrodes 1, 2, ... For example, if the signals synthesized in the latest section are v and i,
v, i = p1 × SNR1, i × v1, i + p2 × SNR2, i × v2, i + ...
Will be. p1, p2, ... Are the polarities of each ECG electrode and take a value of +1 or -1.

Normally, once the mounting location of the ECG electrode is determined, the polarity of the PQRST wave does not change, so it is not necessary to change the polarity for each section. That is, the same values can be used for p1, p2, ... Even if the interval changes.

On the other hand, there is a phenomenon that the shape of the PQRST wave changes depending on the mounting location in a plurality of ECG electrodes. For example, in a 12-lead electrocardiograph, the S wave of the V1 electrode is larger than the R wave. In this case, for example, the polarity of the composition may be determined so that the QRS amplitude is maximized.

The R wave re-extraction unit 234 re-extracts the R wave for the combined signals v, 1: v, i-1: v, i-2 ... The SNR of the composite wave is approximately the sum of the SNRs of the ECG electrodes 1, 2, ... Before synthesis, and the SNR can be improved to extract the R wave.

As described above, during exercise, there are sections where the SNR is very bad and sections where the SNR is good to some extent, and since it depends on the motion vector and the mounting location, weight synthesis is performed by a plurality of ECG electrodes 1, 2, ... It is possible to reduce the section where the SNR is very bad. This leads to reduction of false detection and omission of RRI.

[Third Embodiment]
Here, a sensor structure having a plurality of ECG electrodes for electrocardiographic detection will be described. Normally, increasing the number of ECG electrodes increases the number of terminals for connecting a case (containment vessel) for accommodating a signal processing circuit or the like, and also inevitably increases the electrode area. , We are trying to suppress these points as much as possible.

-First aspect-
FIG. 9 shows an example in which the ECG electrode 3 is also provided on the bottom surface of the case 310 to minimize the increase in the number of terminals and the area occupied. In this example, the case 310 is fixed to the skin surface via the belt 301. Adhesive tape may be used instead of the belt 301. Although not shown, the case 310 has a built-in signal processing circuit and the like.

As shown in FIGS. 9A and 9B, in this example, the ECG electrodes 1 and 2 arranged on both sides of the case 310 as ECG electrodes and the bottom surface of the case 310 (the surface on the side in contact with the skin surface). It is provided with three ECG electrodes of the provided ECG electrodes 3.

As described above, the ECG electrodes 1 and 2 are preferably electrodes made of Ag / AgCl or conductive plastic, and these ECG electrodes 1 and 2 have terminals 321a and 321b provided on the upper surface of the case 310. It is connected to a signal processing circuit or the like in the case 310 via.

Like the ECG electrodes 1 and 2, the ECG electrode 3 is preferably an electrode made of Ag / AgCl or conductive plastic and is provided on the bottom surface of the case 310, but a conductive gel may be used for the ECG electrode 3.

The ECG electrodes 1, 2 and 3 are attached so as to be in contact with the skin, and the insulating cover 302 is arranged so as to cover the terminal portions of the ECG electrodes 1 and 2. The insulating cover 302 is preferably arranged so as to project 10 mm or more from the end of the case 310. This is to minimize the decrease in insulation resistance between the ECG electrodes 1 and 2 due to sweat.

10 (a) and 10 (b) show an example in which the ECG electrode 3 arranged on the bottom surface of the case 310 is divided into two to form the ECG electrodes 3a and 3b, whereby the number of electrodes is increased.

FIG. 11 shows an example in which four ECG electrodes 4 to 7 are further provided in addition to the above-mentioned ECG electrodes 1, 2 and 3. Of these, the ECG electrodes 4 and 5 are arranged on the belt 301 so as to be in contact with the side surface of the body, and the ECG electrodes 6 and 7 are arranged on the belt 110 so as to be in contact with the back surface of the body.

The side surface of the body serves as a fulcrum that supports the fabric of the belt and clothing, and is a part where there is relatively little deviation during exercise. The combination of the back, front, and sides of the body increases the probability of producing a low-artifact state at some ECG electrode at a given moment during a movement that stretches the body back and forth and left and right.

-Second aspect-
In this second aspect, as shown in FIGS. 12A to 12C, a plurality of (for example, three) ECG electrodes 1 to 3 for electrocardiographic detection and a thermometer 11a for measuring core body temperature, It is equipped with 11b. When it is not necessary to distinguish between the thermometers 11a and 11b, they are collectively referred to as the thermometer 11.

A substrate 330 and two thermometers 11a and 11b are provided in the case 310 to measure the heat flow between the skin and the environment. One thermometer 11a is arranged on the bottom surface of the case 310, and the other thermometer 11b is provided on the substrate 330 away from the thermometer 11a.

As shown, one set of thermometer pairs (thermometers 11a, 11b) can measure one heat flow (SHF: Single Heat Lux). It is also possible to measure two heat flows by using two sets of thermometer pairs (DHF: Dual Heat Flux). In this case, the ECG electrode 3 is provided on the bottom surface of the case 310 so as to come into contact with the skin.

-Third aspect-
In this third aspect, an example of connecting the substrate 330 to the thermometer 11 and the ECG electrodes 1 to 3 will be described. FIG. 13a shows the case where the ECG electrode 3 is located on the entire bottom surface of the case 310, and FIG. 13b shows the case where the ECG electrode 3 which is the bottom surface electrode is divided into the ECG electrode 3a and the ECG electrode 3b.

In either case, the upper lid 311 of the case 310 is provided with terminals 321a and 321b that are electrically connected to the ECG electrodes 1 and 2 attached to the belt 301 (or wear). When it is not necessary to distinguish between terminals 321a and 321b, the terminals are collectively referred to as terminal 321.

The terminals 321a and 321b are connected to the substrate 330 in the case 310 by wirings L1 and L2, respectively. On the bottom surface of the case 310, an insulating sheet 312 is placed inside and the ECG electrode 3 is placed outside.

A first thermometer 11a is arranged on the insulating sheet 312. A second thermometer 11b is arranged on the substrate 330. The thermometers 11a and 11b are preferably arranged in the central portion of the case 310. The second thermometer 11b may be arranged on the lower surface side of the substrate 330.

If the function of the radiation thermometer is added to the second thermometer 11b so that the substrate temperature and the bottom surface temperature can be measured at the same time, the first thermometer 11a can be omitted.

A through hole 313 is provided in the insulating sheet 312, and the ECG electrode 3 (bottom electrode) and the substrate 330 are connected by wiring L3 via the through hole 313. Further, the first thermometer 11a and the substrate 330 are appropriately connected by wiring. Flexible printed wiring can also be used as the wiring.

Plastic can be used as the insulating sheet 312. It is preferable to reduce the thickness of the insulating sheet 312 so that the temperature of the first thermometer 11a is as close to the skin temperature as possible to increase the temperature difference from the second thermometer 11b in order to increase the sensitivity.

Further, in order to reduce the thickness of the case 310, it is preferable that the thickness of the insulating sheet 312 is thin. If a high-strength plastic material is used, the thickness can be about 1 mm. Since the insulating sheet 312 bears the strength of the bottom surface of the case 310, the thickness of the ECG electrode 3 on the bottom surface using expensive silver can be reduced. As the ECG electrode 3 on the bottom surface, a sheet-shaped Ag / AgCl can be used.

Further, as the ECG electrode 3 on the bottom surface, one obtained by plating Ag / AgCl on a metal such as iron having a high Young's modulus can also be used. Since the ECG electrode 3 bears the strength of the bottom surface of the case 310, the thickness of the insulating sheet 312 can be reduced and the temperature of the first thermometer 11a can be brought close to the skin temperature.

In the example of FIG. 13b, when the ECG electrode 3 on the bottom surface is divided into two ECG electrodes 3a and ECG electrodes 3b, both side portions 312a and 312b of the insulating sheet 312 on which the divided electrodes 3a and 3b are arranged are the electrodes 3a, By thinning by the thickness of 3b, the surface in contact with the skin can be flattened.

Immediately below and around the first thermometer 11a is an important surface for measuring heat flow, and if a gap is formed between this surface and the skin, an error will occur in heat flow measurement. Since contact with the skin is naturally important for the ECG electrodes 3a and 3b as well, it is important that no step is formed on the bottom surface of the case 310.

As a relative matter, in the insulating sheet 312, the thickness of the central portion 312c between the ECG electrodes 3a and the ECG electrodes 3b is increased by the thicknesses of the electrodes 3a and 3b, and a step is formed on the bottom surface of the case 310. May not occur.

-Fourth aspect-
In the fourth aspect, as shown in FIG. 13c, the ECG electrode 3 on the bottom surface is divided into four parts, and the insulating sheet 312 is used as the first insulating sheet, and separately on the bottom surface of the case 310. An insulating sheet 317 is provided.

Similar to the third aspect, the first thermometer 11a and the first insulating sheet 312 are arranged on the bottom surface of the case 310. On the skin side (bottom side) of the first insulating sheet 312, four ECG electrodes 3a to 3d obtained by dividing the ECG electrode 3 into four are arranged.

A dummy electrode D is arranged in and around the first thermometer 11a so that there is no gap under the first thermometer 11a. An electrically insulating dummy sheet having the same thickness may be used instead of the dummy electrode D. Further below that, a second insulating sheet 317 is arranged.

The second insulating sheet 317 has a larger area than the bottom surface of the case 310, and the peripheral portion thereof protrudes from the bottom surface of the case 310. An insulator such as plastic is used for the second insulating sheet 317.

Conductive gels 315a to 315d and non-conductive gels 316 are arranged on the bottom surface of the second insulating sheet 317. An opening 318 is provided in the central portion of the second insulating sheet 317, and the divided ECG electrodes 3a to 3d on the case side are electrically connected to the conductive gels 315a to 315d, respectively. Further, the dummy electrode D and the non-conductive gel 316 are brought into thermal contact with each other. The second insulating sheet 317 can be disposable.

By making the conductive gels 315a to 315d and the non-conductive gels 316 sticky, they can be adsorbed on the skin including the case 310. There is a merit that you can put on and take off your clothes without taking them off.

[Fourth Embodiment]
In the embodiment of the wear worn on the upper body of the human body having a plurality of ECG electrode pads and heat flow pads, ECG electrode pads E, heat flow pads Th, and signal processing circuit P are provided on the wear W in FIGS. An example is shown. FIG. 14A is the front side of the wear W, and FIG. 14B is the back side of the wear W.

As shown in FIG. 14A, in the case of the human body, there are prominent (high) positive electrocardiographic potentials on the left and right slightly below the ribs on the front surface of the body. Furthermore, there is a portion where the negative potential of the electrocardiogram is remarkable (high as an absolute value) in the epigastrium and above and below it. By providing the ECG electrode pad E in this region, the signal strength can be increased.

The ECG electrode pad provided in the portion where the positive potential of the electrocardiogram is prominent is E (+), and the ECG electrode pad provided in the portion where the negative potential of the electrocardiogram is prominent is E (-). When it is not necessary to distinguish them, the ECG electrode pad E is simply used.

If the ECG electrode pad E is too large, the portion having a high potential and the portion having a relatively low potential in the vicinity thereof may be short-circuited, which is not preferable. On the other hand, arranging a large number of small ECG electrode pads E imposes a burden on signal processing and wiring routing.

Since the area of the high positive potential is rather small, as an example, one ECG electrode pad (E +) is placed on each side, and three ECG electrode pads (E-) are placed in the central part with high negative potential. Is preferable. As a result, a large signal can be obtained, the above-mentioned problems are alleviated, and the SNR improvement effect of the plurality of electrodes is achieved.

With reference to FIG. 14B, the back surface of the body also has a potential distribution similar to that of the front surface, although it is smaller than the front surface. The number of electrodes, the number of wirings, and signal processing will be increased, but the above effect can be further improved by appropriately using this part (the back surface of the body).

The heat flow pad Th is composed of a thermometer 11 for measuring the heat flow and a heat insulating material 432, which will be described later, and allows the heat flow to flow in the vertical direction with respect to the body surface. The reason for arranging a plurality of heat flow pads Th is that there is a temperature difference in the deep part of the body (for example, the upper part and the lower part of the abdomen) and that there is an artifact (factor of error) in the heat flow measurement and it is reduced. ..

If a gap is created between the skin and the heat flow pad Th, it becomes an artifact, so it is preferable to wear it on a flat surface as much as possible. Pectoral muscles and chest fat, gynecomastia, and the area around the shoulder blades on the back impair flatness, so these areas should be avoided.

From the above viewpoint, it is preferable to arrange the heat flow pad Th around the sternum, which is relatively flat at the upper part, and under the ribs, which is relatively flat at the lower part. In the example of FIG. 14A, the locations of the ECG electrode pad E and the heat flow pad Th do not overlap, but the ECG electrode pad E and the heat flow pad Th are housed in one package to provide both functions. It is also possible to combine them.

Subcutaneous fat reduces the heat flow and increases the heat time constant. It also reduces the sensitivity of the heat flow meter and slows down the response speed. Furthermore, from the line of force analogy of the electric parallel plate capacitor, the phenomenon that the surrounding flux bends as the distance between the parallel plates increases (three-dimensional effect) occurs, and the environmental temperature increases as the distance from the deep part to the heat flow meter increases. Being susceptible to.

On the front of the body, the area around the sternum is relatively low in subcutaneous fat, so it is recommended to select the area around the sternum for people with thick subcutaneous fat. In addition, since the back surface of the body often has less subcutaneous fat than the front surface, the above-mentioned back location can be selected.

Since artifacts also occur in the ground electrode G, it is preferable to secure a large area. It is preferable to secure a large area on the back side where the electric potential is relatively small, particularly under the neck where the electric potential is small, and further around the waist so as not to disturb the electric potential distribution of the electrocardiogram described above.

The signal processing circuit P includes a wireless circuit for communicating with the outside. In order to extend the communication distance, it is preferable to raise the ground clearance of the antenna. Further, depending on the content of the exercise, the back may be put on the ground, and it is preferable that the user has a choice so that the signal processing circuit does not interfere with the exercise.

From these viewpoints, it is preferable that the signal processing circuit P can be appropriately arranged around the neck on the back and further around the neck on the front side. The signal processing circuit P can be made thinner and smaller by technologies such as SiP (System in Package) and COP (Chip on Board), and the signal processing and the battery can be placed in different places and connected by wiring. Can be done.

A thin laminated battery can be detachably placed, for example, at the position shown in FIG. 14aB. As a result, the thickness and area of the signal processing circuit P can be reduced. You can reduce the weight and thickness around the neck.

Next, according to FIGS. 15 (a) to 15 (c), the GND (which is wired on the wear W in order to connect the ECG electrode pads E (+) and E (-) and each heat flow pad Th to the signal processing circuit P A method for reducing the effects of static electricity, electromagnetic induction, electrostatic coupling, and sweat, which are factors of artifacts, will be described for the ground) wiring 410.

FIG. 15C shows the details of the GND wiring 410. According to this, the GND wiring 410 is formed by sequentially laminating a coated conductor 411 serving as a signal line, a first insulating sheet 412a, a GND conductor 413 serving as a GND electrode, and a second insulating sheet 412b on the wear cloth 401.

It is preferable that the wear fabric 401 has a property of being less likely to be charged with static electricity while maintaining comfort, breathability, and holdability with compression. Even so, it is difficult to eliminate static electricity, and countermeasures against static electricity are required. Further, it is necessary to reduce inductive noise from an AC power source such as an AC100V power source and electrostatic noise due to capacitive coupling between the human body and surrounding objects.

By using the coated conductor 411 as the signal line, when the wear cloth 401 absorbs sweat, it prevents a short circuit with other wiring due to the salt content of the sweat. In the heat flow pad Th, it is preferable to use two coated conductors as stranded wires (twisted pair). By using a twisted pair of signal lines from a thermometer (for example, a thermistor), common mode noise can be removed more effectively when the signal processing circuit P processes it as a difference signal.

The (sandwich) structure in which the GND conductor 413 is arranged between the first insulating sheet 412a and the second insulating sheet 412b prevents the GND conductor 413 from short-circuiting with other GND wiring through the wear cloth 401 due to sweat. The GND conductor 413 is preferably grounded at one point in the signal processing circuit P.

The GND conductor 413 has a width so as to sufficiently cover the coated conductor 411 which is a signal line. For example, it is preferable to have a width of about 10 mm in order to suppress inductive noise and electrostatic noise.

Placing the coated conductor 411, the GND conductor 413, and the insulating sheets 412a and 412b on the environment side (opposite to the skin) with respect to the wear cloth 401 in order to suppress external induction noise and electrostatic noise. Although it is preferable, it can be arranged on the skin side of the wear fabric 401 depending on the required SNR, the design of the wear, and the like.

Next, the structure of the ECG electrode pad E will be described with reference to FIGS. 16A and 16B. The ECG electrode pad E has a laminate of the ECG electrodes 421, the first insulating sheet 422a and the spring material 423 on the side of the wear cloth 401 facing the skin, and is on the environment side of the wear cloth 401 (the side opposite to the skin). ) Contains a laminate of a second insulating sheet 422b, a GND conductor 424, and a third insulating sheet 422c.

The ECG electrode 421 is arranged so as to be in contact with the skin surface. As described above, the ECG electrode 421 can be made of a metal containing Ag / AgCl or Ag as a main component or a conductive plastic. The electrode area has the above-mentioned trade-off, and is preferably about 100 to 500 mm2.

The first insulating sheet 422a is arranged on the ECG electrode 421 so as to project from the ECG electrode. This is to prevent the ECG electrode 421 from short-circuiting with the other ECG electrodes 421 via the wear W when the wear cloth 401 absorbs sweat. When sweating, it is preferable to secure a resistance value of 100 kΩ or more with other ECG electrodes, and the overhang length is preferably about 5 to 10 mm.

The spring material 423 acts as a spring that keeps the skin in contact with the ECG electrode 421. The surface of the skin is uneven, and the height of the peaks and valleys changes with breathing and exercise. A part of the skin surface becomes a concave part, and a convex part around it forms a structure that supports the wear fabric.

The ECG electrode 421 hanging from the garment fabric 401 may be separated from the skin or the contact pressure may change as it is. Along with this, the above-mentioned changes in chemical potential occur, which is a major factor in artifacts.

The spring material 423 plays a role of pressing the ECG electrode 421 against the skin with a constant pressure even when the skin surface is recessed. Functionally, it has a structure in which a large number of small springs are arranged in a plane. As such a material, a sponge, a cushion, a foaming material, a bubble wrap material, or the like can be used. Plastics such as cotton and polyurethane can also be used. The thickness is preferably about several mm to 10 mm without applying pressure. The vertical relationship between the spring material 423 and the insulating sheet 422a may be reversed.

In order to minimize the mixing of electrostatic noise and inductive noise into the ECG electrode 421, a GND region is provided on the opposite side of the ECG electrode 421 with the wear cloth 401 interposed therebetween. Similar to the GND wiring 410, the structure in which the conductor 424 serving as the GND is sandwiched between the second and third insulating sheets 422b and 422c is arranged so as to project from the ECG electrode 421.

It is preferable that the GND conductor 424 is about 5 to 10 mm and is arranged so as to project from the periphery (4 sides) of the ECG electrode 421. A GND laminate in which the GND conductor 424 is sandwiched between the insulating sheets 422b and 422c can also be arranged on the spring material 423 and under the wear cloth 401.

With reference to FIGS. 17 (a) and 17 (b), the coated conductor 411 in the GND wiring 410 is connected to the ECG electrode 421, and the ECG electrode 421 is connected to the signal processing circuit P via the coated conductor 411.

The coated conductor 411 is pulled out from the environment side of the wear cloth 401 through the wear cloth 401, the spring material 423 and the insulating sheet 422a, and is connected to the ECG electrode 421 via the contact 425.

For the contact 425, a caulking metal fitting that mechanically sandwiches the ECG electrode 421 from above and below can be used. Since the covering conductor 411 penetrates the insulating sheet 422a, a gasket 426 may be provided at the penetration point of the covering conductor 411 of the insulating sheet 422a so that moisture such as sweat that has permeated the wear fabric 401 does not reach the ECG electrode 421. preferable. As the gasket 426, an adhesive or a ring-shaped plastic can be used.

Next, the heat flow pad Th will be described with reference to FIGS. 18A and 18B. The first insulating sheet 431a is arranged so as to be in contact with the skin surface, and the heat insulating material 432 provided with the thermometers 11a and 11b is arranged on the first insulating sheet 431a.

One thermometer 11a is arranged on the lower surface side (skin surface side) of the heat insulating material 432, and the other thermometer 11b is arranged on the environmental surface side (anti-skin surface side) of the heat insulating material 432. Both the thermometers 11a and 11b are preferably arranged at overlapping positions in the central portion of the heat insulating material 432. The insulating sheet 431a prevents sweat from the skin from reaching the thermometer 11a on the lower surface side.

The thermometers 11a and 11b measure the heat flow flowing from the skin to the environment. The temperature difference generated by multiplying the thermal resistance of the heat insulating material 432 and the heat flow can be detected by the thermometers 11a and 11b, and the heat flow can be obtained (heat flow meter by SHF).

Normally, the skin temperature has a temperature of about 30 ° C., but when a gap is created, heat exchange with the environmental temperature is performed instantly, and even if contact is restored, it takes tens to hundreds of seconds to return to thermal equilibrium. Needs. The deep temperature measurement during that period will be accompanied by a large error.

A spring material 433 is arranged between the wear fabric 401 and the heat insulating material 432. The spring material 433 has an effect of preventing the contact between the skin and the heat flow measurement structure (insulation material + thermometer) from being lost, similarly to the spring material 423 in the ECG electrode pad E.

Further, by arranging a GND laminate having the GND conductor 434 sandwiched between the second and third insulating sheets 431b and 431c on the environmental surface side of the wear cloth 401, a thermometer signal (resistor change in the case of a thermistor). It is possible to suppress the mixing of noise superimposed on the.

Next, the wiring connection to the thermometers 11a and 11b will be described with reference to FIGS. 19A and 19B. In FIG. 19B, the first insulating sheet 431a, the heat insulating material 432 having the thermometers 11a and 11b, and the spring material 433 are not shown.

The coated conductor 411 of the GND wiring 410 that has passed from the signal processing circuit P to the environment side of the wear cloth 401 is passed to the skin side in order to connect to the thermometers 11a and 11b. The wiring is a twisted pair wiring 411a for the thermometer 11a and a twisted pair wiring 411b for the thermometer 11b, which are connected to the thermometer 11a on the lower surface side of the heat insulating material 432 and the thermometer 11b on the upper surface side of the heat insulating material 432, respectively. Will be done. It is also possible to connect one terminal of the thermometer 11a and one terminal of the thermometer 11b to make three wires. It is also possible to make a stranded line structure with three lines.

Next, a configuration example of the heat flow pad Th by the DHF method having two sets of heat flow meters will be described with reference to FIGS. 20 (a) and 20 (b). In this case, four thermometers 11a to 11d and two heat insulating materials 432a and 432b are used. Other configurations may be the same as the heat flow pad described with reference to FIG.

Of these, the thermometers 11a and 11b are arranged on the lower surface side and the upper surface side of one heat insulating material 432a as the thermometer vs. TP1, and the thermometers 11c and 11d are arranged on the lower surface side and the upper surface side of the other heat insulating material 432b as the thermometer vs. TP2. Placed on the side.

In this way, by providing two sets of thermometer pairs TP1 and TP2, two heat flows can be measured. By changing the thermal resistance of the heat insulating materials 432a and 432b, heat flows of different sizes can be created, and the unknown subcutaneous thermal resistance can be calculated to calculate the core body temperature.

Wiring connections to the thermometers 11a to 11d will be described with reference to FIGS. 21 (a) and 21 (b). In FIG. 21B, the first insulating sheet 431a, the heat insulating material 432a having the thermometers 11a and 11b, the heat insulating material 432b having the thermometers 11c and 11d, and the spring material 433 are not shown.

The thermometers 11a to 11d are connected to the signal processing circuit P via two sets of wiring 410A by the covering conductor 411 toward the thermometer vs. TP1 and two sets of wiring 410B by the covering conductor 411 toward the thermometer vs. TP2, respectively. Will be done.

If one terminal of each thermometer is combined into one wiring, a total of five wirings can be made. Further, the number of wirings can be reduced by providing, for example, a semiconductor switch for selectively switching the thermometer on each heat flow pad.

Next, the heat insulating material suitable for the heat flow pad for DHF described with reference to FIGS. 20 and 21 will be described with reference to FIGS. 22 (a) to 22 (c).

First, in the example of FIG. 22A, a large number of bubbles as a bubble wrap (hollow in this example) are placed on the lower surface film 441 having a size (area) corresponding to the combined size of the heat insulating materials 432a and 432b. A plurality of columnar air sacs) B are arranged, and the gas to be sealed by the bubble wrap Ba in the portion of one heat insulating material 432a and the bubble wrap Bb in the portion of the other heat insulating material 432b is changed.

Further, the top film 442 and the side film 443 are laminated to form an airtight gas mat, and the inside of the gas mat is divided into a gas chamber Ra on the heat insulating material 432a side and a gas chamber Rb on the heat insulating material 432b side by a partition film 444. Each of them is filled with a different gas.

The bubble body Ba on the heat insulating material 432a side and the gas sealed in the gas chamber Ra may be the same gas, and the bubble body Bb on the heat insulating material 432b side and the gas sealed in the gas chamber Rb may be the same gas.

It has two types of thermal resistance by changing the thermal conductivity of the gas sealed in the bubble body Ba and the gas chamber Ra on the heat insulating material 432a side and the gas sealed in the bubble body Bb and the gas chamber Rb on the heat insulating material 432b side. The heat insulating materials 432a and 432b can be formed.

Hydrogen 0.3, helium 0.14, etc. can be used as a gas having a high thermal conductivity (unit of each numerical value is W / mK). On the other hand, air 0.026, argon 0.016, and carbon dioxide gas 0.015 can be used as a gas having a low thermal conductivity (unit of each numerical value is W / mK).

The area of the entire heat insulating material 432 including the heat insulating materials 432a and 432b is determined so as to reduce the three-dimensional effect due to the subcutaneous thickness described above. The shape of the heat insulating material 432 may be cylindrical. For example, in a plan view, the vertical and horizontal lengths may be about several tens of mm (several tens of mm in diameter), preferably 30 mm or more. The subcutaneous thickness is usually 5 mm or more, and has the effect of suppressing the influence of changes in the environmental temperature.

The thickness of the heat insulating material 432 is preferably several mm, preferably 2 mm or more. By increasing the thickness, the sensitivity of heat flow measurement increases, but the thickness of the garment increases, so that comfort and heat dissipation decrease. On the other hand, if the thickness is too thin, the bottom surface and the top surface of the bubble body may come into contact with each other when the body surface is displaced, and the thickness variation tends to appear as an error, which is not preferable.

As described above, if there is a gap between the heat flow pad Th and the skin, a large error will occur. The bubble body B is deformed to fit the unevenness of the body. It is pressed against the body surface by the compression of the spring material and wear, and it is possible to prevent the formation of gaps even during exercise. Even if the shape of the cell B changes microscopically, the change in thermal resistance of the heat insulating material 432 as a whole may be within the permissible error. Since gas has a lower thermal conductivity than liquid or solid, the sensitivity of the heat flow meter can be increased.

As a similar configuration, as shown in FIG. 22B, the adjacent cell B may have a structure separated by a partition. It is also possible to enclose an aggregate of small beads instead of a gas in the cell B or the film.

Further, as shown in FIG. 22C, synthetic resin sheets 451 and 452 having different thermal resistances may be used as the heat insulating material 432. The synthetic resin is preferably a material that can change its shape, such as a rubber material or a foam material. Two types of thermal resistance can be provided by changing the composition, additives, and foaming ratio of these materials.

[Fifth Embodiment]
-First aspect-
The fifth embodiment is an embodiment for quantifying and correcting temperature artifacts, and the first embodiment has, as its basic configuration, a heat flow measuring unit 500 and a deep temperature calculation unit 510 as shown in FIG. 23. The noise calculation unit 520 and the deep temperature output unit 540 are provided.

The heat flow measuring unit 500 measures one or a plurality of heat flows flowing from the living body toward the surrounding environment by the SHF method, the DHF method, or the like. The deep temperature calculation unit 510 calculates the deep temperature using the heat flow, the thermal resistance under the skin, and the temperature of the epidermis (body surface). The noise calculation unit 520 calculates the noise superimposed on the deep temperature. The deep temperature output unit 540 applies processing to the deep temperature according to the calculated noise, and outputs the result.

-Second aspect-
Preferably, as a second aspect, as shown in FIG. 24, a noise comparison unit 530 is further provided after the noise calculation unit 520, and the noise period data calculated by the noise calculation unit 520 is removed.

In this example, the heat flow measuring unit 500 adopts the DHF method, includes two sets of thermometer pairs TP1 and TP2 as described in FIG. 20 (b) above, and as shown in FIG. 25, the temperature. The two heat flows Is1 and Is2 are measured with the meter pairs TP1 and TP2, and the skin temperatures Tsk1 and Tsk2 are measured with the thermometer on the skin surface side included in the thermometer pair TP1 and TP2.

The core temperature calculation unit 510 calculates the Rthbody from (Tsk2-Tsk1) / (Ith1-Its2) with the internal thermal resistance from the deep tissue of the living body to the body surface as the Rthbody, and then (Ith1 × Rthbody + Tsk1) or (Ith2 ×). The time series of the core body temperature Tc of the living body is obtained from Rthbody + Tsk2).

The noise calculation unit 520 has a high-pass filter (HPF) and outputs a component having a specific frequency or higher with the deep temperature Tc as an input. As a high-pass filter, for example, a first-order filter and a frequency of about 0.001 Hz can be set as a specific frequency (cutoff frequency).

As a result, the temperature fluctuation component having a period of 160 seconds or less passes through as calculated noise with almost no attenuation. As the amount of noise, the square moving average, that is, the effective value can be output.

In addition to this, temperature noise may appear in a specific body posture. For example, in a left-facing lie with the heat flow pad Th as a heat flow meter attached to the left side of the abdomen, when the tension of the belt fixing the heat flow pad Th is loosened or the body surface is displaced, the skin and the heat flow pad Th The present inventor has observed a phenomenon in which a gap is formed between the gaps, which causes a large temperature noise.

Changes in body posture can be detected by an acceleration sensor. Since the temperature noise is generated later than the change in posture, it is possible to generate pseudo temperature noise that is easy to remove after detecting a specific posture and output it as calculated noise.

The noise comparison unit 530 compares the temperature noise calculated by the noise calculation unit 520 with a predetermined threshold value. The threshold value can be determined by the required temperature error, but can be set to a value of, for example, several tens to several hundreds of m ° C.

The deep temperature output unit 540 outputs the deep temperature Tc, for example, if the effective noise value is less than the threshold value. That is, the output of the deep temperature Tc is stopped during the period when the noise equal to or higher than the threshold value is calculated. The output stop part is blank, but for example, as a user interface (UI), by connecting the points immediately before and after the blank, it is possible to prevent the user, other programs, and the system from making a false judgment due to noise. it can.

Since an error occurs in the line connected by the threshold value, the influence of the error can be reduced by extending the noise generation period back and forth and masking.

-Third aspect-
In the third aspect, as shown in FIG. 26, a plurality of heat flow measuring units 500a, 500b, ... As the heat flow measuring unit 500, a deep temperature calculation unit 510, a noise calculation unit 520, and a noise / measurement unit comparison unit. It includes a 531 unit, a noise / threshold value comparison unit 532, and a deep temperature output unit 540.

The deep temperature calculation unit 510, the noise calculation unit 520, and the deep temperature output unit 540 may be the same as those in the first and second aspects. Further, the heat flow measuring units 500a, 500b, ... Adopt the DHF method.

With reference to the operation explanatory diagram of FIG. 27, there may be a plurality of deep temperature calculation units 510, but here, the heat flow measurement units 500a, 500b, ... Are sequentially switched and connected to one arithmetic circuit, as described above. In addition, the deep temperature Tca, Tcb, ... Of each part is calculated based on the data such as the heat flow and the skin temperature from the heat flow measuring units 500a, 500b, ....

The noise calculation unit 520 calculates the effective temperature noise values Nca, Ncb, ... In each deep temperature, as in the second aspect.

The noise / measurement unit comparison unit 531 compares the temperature noise effective values between the heat flow measurement units and selects the minimum temperature noise effective value.

The noise threshold comparison unit 532 compares the minimum temperature noise effective value with a predetermined threshold value.

If the minimum effective temperature noise value is less than the threshold value, the deep temperature output unit 540 outputs the deep temperature Tc extracted by the measuring unit. If the minimum temperature noise effective value is equal to or greater than the threshold value, a blank is output.

Similar to the case of ECG signal synthesis, the influence of the artifact can be reduced by synthesizing the signals from the plurality of heat flow measuring units according to the SNR. There may be an offset in the deep temperature between multiple heat flow pads. In that case, the offset can be recorded when there is little noise and corrected when synthesizing.

-Fourth aspect-
With reference to FIGS. 28 and 29, in the fourth aspect, a plurality of calculated deep temperature values are weighted according to noise and combined. Therefore, the weight synthesis unit 533 is used instead of the noise / measurement unit comparison unit 531 and the noise / threshold value comparison unit 532 in the third aspect. The heat flow measuring units 500a, 500b, ..., The deep temperature calculation unit 510, and the noise calculation unit 530 perform the same processing as in the third aspect.

The weight synthesis unit 533 multiplies the deep temperature Tca, Tcb, ... Measured by each heat flow measurement unit 500a, 500b, ... By the reciprocal of the calculated noise, and adds the multiplication results of each heat flow measurement unit. , Divide by the sum of the reciprocals of each heat flow measuring unit. The deep temperature output unit 540 outputs the above calculation result as a synthesized Tc. Tc is expressed by the following formula.
Tc = (1 / Nca x Tca + 1 / Ncb x Tcb) / (1 / Nca + 1 / Ncb)

As a result, the measured values of each heat flow measuring unit 500 (500a, 500b, ...) Are greatly evaluated and synthesized if the noise is small, and the results of each heat flow measuring unit can be effectively used. .. The synthetic SNR is approximately the sum of the SNRs of each heat flow measuring section.

-Fifth aspect-
As shown in FIG. 30, the fifth aspect has, as a basic configuration, a heat flow measuring unit 500, an environmental temperature measuring unit 501, a false signal generating unit 502, a deep temperature calculating unit 503, and a deep temperature output unit 540. , Correct the temperature false signal.

The heat flow measuring unit 500 measures one or more heat flows flowing from the living body toward the surrounding environment by the SHF method or the DHF method. The environmental temperature measuring unit 501 measures the environmental temperature. The false signal generator 502 creates a false signal from the ambient temperature. The deep temperature calculation unit 503 calculates the deep temperature using the heat flow, the thermal resistance under the skin, and the temperature of the epidermis. The deep temperature output unit 540 calculates and outputs a new deep temperature by processing the deep temperature according to the generated false signal.

-Sixth aspect-
As shown in FIG. 31, the sixth aspect further includes a false signal removing unit 504 in addition to the fifth aspect, and its operation will be described with reference to the schematic diagram of FIG. 32.

In the heat flow measurement of the heat flow measuring unit 500, since the heat flow Is that flows from the living body toward the environment is measured, it is affected by the change in the environmental temperature. The three-dimensional effect due to the subcutaneous thickness described above is one example. This may generate a large false signal at the deep temperature Tc.

The environmental temperature measuring unit 501 is a thermometer that measures the environmental temperature, and can be installed, for example, on the uppermost portion of the case 310 described in the above aspect, or on the surface of the belt 301 or the wear W. Although it is possible to use the temperature acquired at a location close to the environment side of the heat flow measuring unit 500, it is preferable to acquire the temperature at a location where the thermal time constant is small because a delay occurs if there is a thermal time constant.

The false signal generation unit 502 acquires the relationship between the environmental temperature and the false signal in advance, and creates a false signal from the current environmental temperature according to the acquisition result. The false signal has a time response with the ambient temperature as the input. This relational expression is obtained in advance by experiments or the like.

For example, the hot plate is regarded as a deep part and the silicone rubber is regarded as a subcutaneous tissue, and an experiment is conducted in which the environmental temperature is changed while keeping the temperature of the hot plate constant. Since a larger false signal is generated as the silicone rubber becomes thicker, the time response transmission coefficient of the false signal is acquired while changing the thickness of the silicone rubber.

A false signal is generated in the raw deep temperature calculation result due to the change in the environmental temperature, and the false signal removing unit 504 subtracts and removes the false signal from the raw deep temperature calculation result. The deep temperature output unit 540 outputs the above processing result to the user, the administrator, or another program or system.

[Sixth Embodiment]
In the sixth embodiment, the measurement function is diagnosed from the noise measurement of each part. As a basic configuration for that purpose, as shown in FIG. 33, a biological signal measurement unit 610, an environment measurement unit 620, a noise diagnosis unit 630, and an output unit 640 are provided.

The biological signal measuring unit 610 measures signals obtained according to the state of the living body by attaching the biological signal to the living body, including an electric signal generated by the living body. The environment measurement unit 620 measures the state of the environment surrounding the living body. The noise diagnosis unit 630 acquires the noise contained in each measurement unit and diagnoses the state of the measurement function. The output unit 640 outputs the diagnosis result.

Next, a specific configuration will be described with reference to FIG. 34. The biological signal measuring unit 610 includes an ECG measuring unit 611, a heat flow measuring unit 612, and an acceleration measuring unit 613, which measure ECG, heat flow, and acceleration generated by the living body, respectively. On the other hand, the environment measurement unit 620 measures the temperature, humidity, atmospheric pressure, wind speed, atmospheric composition, latitude / longitude, etc. surrounding the living body.

The ECG measurement unit 611 and the heat flow measurement unit 612 are not unique to the sixth embodiment, and the ECG measurement unit 611 may have the same configuration as the ECG measurement unit 110 described above, and the heat flow measurement unit 612 also has the same configuration. It may have the same configuration as the heat flow measuring unit 500 described above.

The noise diagnosis unit 630 includes an ECG / SNR comparison unit 631, a deep temperature / noise comparison unit 632, a motion determination unit 633, an environment determination unit 634, and a threshold value generation unit 635.

The ECG / SNR comparison unit 631 compares the SNR of the ECG electrode with the threshold value generated by the threshold value generation unit 635. As described above, the ECG electrode is preferably composed of Ag / AgCl or a conductive plastic, but as the measurement is repeated, the ECG electrode reacts with a precipitated substance from a living body, is oxidized, or is physically damaged. Or something. Further, the belt 301 and the wear W that support the ECG electrodes absorb sweat, the insulating sheet is deteriorated, and the wear W is damaged.

As a result, noise may increase or the signal may decrease and the SNR may deteriorate even at rest. In addition, operational artifacts may be larger than normal and occur frequently.

Precipitated substances from the living body can be removed to some extent by washing the ECG electrodes, belts, and clothing, and the initial function may be restored. Even in heat flow measurement, the heat insulating material may be deformed or physically damaged during use.

In addition, if the calibration conditions are changed from the factory-calibrated state, an error may occur with the same calibration parameters. Further, if sweat gets into the signal wiring from the thermometer to the signal processing circuit, an error may occur in the reading of the thermometer. If the GND pattern is broken, the desired shielding effect may not be obtained and noise may increase.

Noise and SNR deterioration may also be due to improper mounting methods. If the size of the body and the size of the belt or garment are different, the ECG electrode or heat flow pad may not be able to contact the skin or may be incompletely contacted.

In particular, when the wearing place is away from the heart like a belt, the ECG signal may become extremely small. In addition, since the area around the scapula is greatly undulated by the movement of the arm, the contact between the ECG electrode or the heat flow pad and the skin may be lost with the movement. The chest is affected by electromyography from the pectoral muscles and unevenness caused by fat and breast. Even if the belt or wear is twisted or wrinkled, it causes noise and SNR deterioration.

In addition, it may become unstable at the start of measurement. Depending on the material of the ECG electrode, the precipitate from the skin may reduce the chemical potential between the skin and the ECG electrode, and the SNR may remain low until the precipitate accumulates. It may be improved by first adding water to the ECG electrode.

In heat flow measurement, large fluctuations such as overshoot and undershoot may occur during mounting depending on the environmental temperature.

Based on these, the threshold generation unit 635 has a "threshold at the start of mounting" as the first threshold, a "threshold at rest" as the second threshold, and a third. It is preferable to appropriately set a "threshold value during exercise" as a threshold value, a "threshold value due to high and low environmental temperature" as a fourth threshold value, and the like.

For example, in exercise, SNR deterioration and noise deterioration are likely to occur in ECG and heat flow in the first place. It is necessary to raise the threshold value from the time of rest, but it is necessary to detect SNR / noise deterioration due to deterioration of members such as ECG electrodes, heat flow pads, belts and wears that appear only during exercise. By detecting the amount of exercise while observing the heart rate, deep temperature, acceleration, environmental temperature, etc., and changing the threshold value as appropriate, it is possible to determine reattachment or cleaning / replacement.

When stationary, SNR and noise are relatively stable. By recording the SNR and noise at rest for each measurement and observing the changes during daily use, it is possible to determine the changes over time in the deterioration of the members described above. If cleaning is promoted at a certain frequency and deterioration progresses without recovery even after cleaning, it is possible to accurately determine deterioration that requires replacement by observing such changes over time.

Since SNR and noise deteriorate at the start and when the environmental temperature changes, it is preferable to determine the first to fourth threshold values by combining the values of the ECG, the heat flow pad, the acceleration sensor, and the environment sensor.

The output unit 640 notifies the user or the administrator of the reattachment instruction, cleaning or replacement, or the like. Regarding the replacement of parts, it is possible to notify the department that supports the customer and prompt the support department to take action.

Furthermore, if there is a problem such as frequent reattachment, it is possible to encourage support from customer support such as checking the size and watering the ECG electrode. These may be performed by the user's administrator on behalf of the user.

By looking at the operation history of each sensor unit such as the ECG measurement unit 611 and the heat flow measurement unit 612, especially the history at rest, it is possible to judge and predict the change over time as described above, and the user can use this information. It can be added to the notification to the administrator and customer support.

1, 2, ... ECG electrode 11 (11a, 11b) Thermometer 110, 210 ECG measurement unit 120, 220 R wave extraction unit 121 Signal calculation unit 122 Wave removal unit 130, 230 SNR calculation unit 131 SNR comparison unit 140, 240 RRI Output part 150, 250 Frequency analysis part 231 SNR / Electrode comparison part 232 SNR / Threshold comparison part 233 Weight synthesis part 234 R wave re-extraction part 301 Belt 310 Case 330 Board 401 Wear fabric 410 GND wiring 411 Covered conductor ( Signal line)
421 ECG electrode 423 Spring material 432 Insulation material 500 (500a, 500b, ...) Heat flow measurement unit 510 Deep temperature calculation unit 520 Noise calculation unit 530 Noise comparison unit 531 Noise / measurement unit comparison unit 532 Noise / threshold value comparison unit 533 Weight synthesis unit 540 Deep temperature output unit

Claims (21)

An ECG measuring unit that acquires an electrocardiographic signal from the body surface of a living body,
An R wave extraction unit that extracts the R wave contained in the above electrocardiographic signal from its characteristics and specifies the position of the R wave peak,
An SNR calculation unit that calculates the SNR (signal-to-noise ratio) of the R wave section specified by the R wave extraction unit, and
An output unit that obtains and outputs the R wave interval from the position of the R wave peak and the SNR of the R wave section, and
A biological signal processing device characterized by being equipped with. A signal calculation unit that calculates the signal amount for calculating the SNR in the SNR calculation unit by aligning and averaging the positions of each R wave using the R wave time extracted by the R wave extraction unit.
A wave removing unit that removes the original electrocardiographic signal such as PQRST from the noisy electrocardiographic signal measured by the ECG measuring unit, and a wave removing unit.
A noise calculation unit that obtains the amount of noise from the noise waveform extracted by the wave removal unit in order to calculate the SNR by the SNR calculation unit.
An SNR comparison unit that compares the calculated SNR and a predetermined threshold value in each section of the R wave, and an SNR comparison unit.
Further equipped with a frequency analysis unit
The output unit calculates the RRI by taking the difference between the times of two consecutive R wave peaks in the section excluding the section where SNR <threshold value in the SNR comparison unit, calculates the calculation result, and outputs the calculation result, and outputs the calculation result. The biometric signal processing device according to claim 1, wherein the analysis unit calculates and outputs the fluctuation of the RRI. The biometric signal processing apparatus according to claim 2, wherein the frequency analysis unit performs frequency analysis based on the least squares method of a sine wave by using RRI with an indefinite interval. The biological signal processing device according to claim 1, wherein the ECG measuring unit processes signals from a plurality of ECG electrodes. An SNR / electrode-to-electrode comparison unit that compares the SNR calculated by the SNR calculation unit between the ECG electrodes and selects the best SNR.
An SNR / threshold value comparison unit that compares the best SNR selected by the SNR / electrode-to-electrode comparison unit with a predetermined threshold value and gives the comparison result to the output unit.
The biometric signal processing apparatus according to claim 4, further comprising. A weight that multiplies each section of the raw waveform of each ECG electrode measured by the ECG measurement unit by the SNR of the section calculated by the SNR calculation unit and adds the polarity of each ECG electrode. Synthetic part and
The R wave re-extracting unit that re-extracts the R wave from the combined wave synthesized by the weight combining unit and gives it to the output unit,
The biometric signal processing apparatus according to claim 4, further comprising. A case as a storage container having a signal processing circuit including the ECG measurement unit, the R wave extraction unit, the SNR calculation unit, and the output unit is further provided, and some of the plurality of ECG electrodes are in the case. It is electrically connected to the ECG measurement unit via a terminal provided on the upper part, and the rest of the plurality of ECG electrodes are arranged on the bottom surface of the case and connected to the ECG measurement unit via a routing wire in the case. The biometric signal processing device according to claim 4, wherein the biometric signal processing device is connected. The biological signal processing apparatus according to claim 7, wherein a heat flow measuring unit having a plurality of thermometers for measuring the heat flow flowing between the inside of the living body and the environment is provided in the case. The bottom surface of the case is closed by an insulating sheet, and ECG electrodes divided into two are arranged on the outer surface side of the insulating sheet at predetermined intervals, and the two ECG electrodes are arranged on the inner surface side of the insulating sheet. The thermometer is arranged at a portion located between the ECG electrodes, and the electrode surface of each ECG electrode and the sheet surface of the insulating sheet between them are present on the same plane. 8. The biological signal processing apparatus according to claim 8. The biological signal processing apparatus according to claim 9, wherein the portion on the outer surface side of the insulating sheet on which the ECG electrode is arranged is formed as thin as the thickness of the ECG electrode. 4. The fourth aspect of the present invention is characterized in that the clothing is worn on the upper body of the living body, and the ECG electrode and the heat flow pad for measuring the heat flow flowing between the living body and the environment are provided in a predetermined portion of the clothing. The biometric signal processor according to the description. The biometric signal processing apparatus according to claim 11, wherein the heat flow pad includes a heat flow measuring means including a heat insulating material and two thermometers arranged on an upper surface and a lower surface thereof. 11. The ECG electrode is provided at a portion of the clothing corresponding to a region where the positive electrocardiographic potential is prominent and a portion corresponding to a region where the negative electrocardiographic potential is prominent. Or the biological signal processing apparatus according to 12. The biometric signal processing apparatus according to claim 11, wherein a spring material for maintaining contact between the ECG electrode and the skin is arranged between the cloth of the clothing and the ECG electrode. The biometric signal processing apparatus according to claim 11, wherein a spring material for maintaining contact between the thermometer on the lower surface side and the skin is arranged between the cloth of the clothing and the heat insulating material. The biological signal processing apparatus according to claim 12 or 15, wherein a gas mat containing a plurality of bubbles arranged on a flat surface is used as the heat insulating material. The heat flow pad is provided with two heat flow measuring means, and the gas mat is divided into a first gas mat for one of the heat flow measuring means and a second gas mat for the other heat flow measuring means. The biological signal processing apparatus according to claim 16, wherein a gas having a different thermal conductivity is sealed in the first gas mat and the second gas mat. A heat flow measuring unit that measures the heat flow flowing between the inside of the living body and the environment,
A deep temperature calculation unit that calculates the deep temperature of a living body based on the temperature information from the heat flow measurement unit,
A noise calculation unit that calculates the noise contained in the deep temperature,
An output unit that calculates and outputs a new deep temperature from the noise calculated by the noise calculation unit and the deep temperature calculated by the deep temperature calculation unit.
A biological signal processing device characterized by being equipped with. The biometric signal processing apparatus according to claim 18, wherein the noise is obtained from the output of a high-pass filter having a deep temperature input. A heat flow measuring unit that measures the heat flow flowing between the inside of the living body and the environment,
An environmental temperature measuring unit that measures the environmental temperature,
A false signal generator that creates a false signal from the environmental temperature measured by the environmental temperature measuring section,
A deep temperature calculation unit that calculates the deep temperature of a living body from the heat flow measured by the heat flow measurement unit, and a deep temperature calculation unit.
An output unit that calculates and outputs a new deep temperature from the false signal generated by the false signal generation unit and the deep temperature calculated by the deep temperature calculation unit.
A biological signal processing device characterized by being equipped with. An ECG measuring unit that acquires an electrocardiographic signal from the body surface of a living body,
A heat flow measuring unit that measures the heat flow flowing between the inside of the living body and the environment,
An acceleration measuring unit that measures the acceleration of a living body,
An environmental measurement unit that measures the environmental conditions surrounding the living body,
An ECG-SNR comparison unit that calculates the signal-to-noise ratio of the electrocardiographic signal and compares it with a predetermined first threshold value.
A deep temperature-noise comparison unit that calculates the noise contained in the heat flow measured by the heat flow measurement unit and compares it with a predetermined second threshold value.
A threshold value generating unit that changes the first threshold value and / or the second threshold value from the acceleration measured by the acceleration measuring unit and the environmental state measured by the environmental measuring unit.
An output unit that outputs a notification signal based on the comparison results from the ECG-SNR comparison unit and the deep temperature-noise comparison unit, and
A biological signal processing device characterized by being equipped with.

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