JP6783091B2 - Vibration frequency measuring device - Google Patents

Description

The present invention relates to a vibration frequency measuring device.

In order to measure the vibration frequency from the signal detected by the vibration sensor, it was common to perform Fourier transform processing or autocorrelation function calculation processing. For example, in Patent Documents 1 and 2, the autocorrelation function of a biological signal obtained from a living body is obtained, the peak (maximum value) is detected from the autocorrelation function, and the frequency of biological information such as heartbeat and respiration is measured. Is described.

Special Publication No. 62-4971 JP 2015-188603

However, the Fourier transform process requires a large amount of calculation such as performing a butterfly calculation. The same applies to the arithmetic processing of the autocorrelation function. Therefore, a high-speed arithmetic processing unit is required to perform Fourier transform processing and autocorrelation function arithmetic processing.

An object of the present invention is to provide a vibration frequency measuring device capable of measuring a vibration frequency with high accuracy by a simple method.

The vibration frequency measuring device according to the present invention is a vibration frequency measuring device that measures the frequency of vibration included in the detection signal of the vibration sensor, and is a filter processing unit that generates a processing signal obtained by extracting a predetermined frequency range from the detection signal. If, for each target frequency of multiple unit calculates a unit related value based the first output value and the reference time of the processed signal at the reference time to the second output value of the processed signal prior half cycle-related The value calculation unit, the total related value calculation unit that calculates the total related value based on the plurality of unit related values having the reference time as a predetermined time for each of the plurality of target frequencies , and the plurality of targets. It includes a frequency specifying unit that specifies the vibration frequency of the detection signal based on the total related value of the frequency.

According to the vibration frequency measuring device, the unit-related value is calculated based on the first data of the reference time and the second data half a cycle before the reference time. Here, the relationship between the first data and the second data will be described. In a sine wave of a specific frequency, the amplitude in phase (π / 4) shows the maximum value, and the amplitude in phase (3π / 4) shows the minimum value. Therefore, the difference between the amplitude in the phase (π / 4) and the amplitude in the phase (3π / 4) is maximized. Further, the absolute value of the amplitude in the phase (π / 4) and the absolute value of the amplitude in the phase (3π / 4) show the maximum value. The phase (π / 4) and the phase (3π / 4) are out of phase by half a period (π / 2).

Therefore, at the frequency f1 corresponding to the specific frequency of the sine wave, one of the unit-related values becomes a large value by using the first data and the second data shifted by half a period (π / 2). On the other hand, at the frequency f2 that does not match the specific frequency of the sine wave, when the first data and the second data shifted by half a period (π / 2) are used, one of the unit-related values is compared with the above case. Is a small value.

However, even if the phases are deviated by half a period (π / 2), the amplitudes at 0 ° and π / 2 are zero, so the difference between the two and the absolute value of the two are minimized. Therefore, a total related value based on a plurality of unit related values whose reference time is a predetermined time is calculated. The total related value has the same relationship with respect to the frequencies f1 and f2 as well as the unit related value. That is, at the frequency f1 corresponding to the specific frequency of the sine wave, the total related value becomes a large value. On the other hand, at the frequency f2 that does not match the specific frequency of the sine wave, the total related value is a small value. Therefore, the frequency specifying unit can specify the vibration frequency based on the total related value.

That is, the vibration frequency is specified by using the relationship between the first data and the second data, which are deviated from each other by half a cycle. Therefore, the calculation of the unit-related value and the calculation of the total-related value are much simpler than the Fourier transform process and the autocorrelation function calculation process. Therefore, the vibration frequency can be measured without using a high-speed arithmetic processing unit.

Further, as described above, the vibration frequency measuring device can specify the vibration frequency with high accuracy by utilizing the relationship between the first data and the second data which are deviated from each other by half a cycle. However, in order for the first data and the second data at the frequency f2 that does not match the specific frequency to have the above relationship, it is necessary to use a signal from which noise has been removed to some extent. Therefore, the unit-related value calculation unit does not use the detection signal itself of the vibration sensor, but uses the processing signal processed by the filter processing unit. In this way, the vibration frequency measuring device can reliably identify the vibration frequency by filtering the detection signal.

It is an overall block diagram of the biological information measurement system of 1st Embodiment. It is an exploded perspective view of the sensor unit of FIG. It is explanatory drawing of the mounting position of the sensor unit of FIG. It is a figure which shows the structure of the vibration frequency measuring apparatus. It is a figure which shows the measurement order and measurement cycle of a pressure sensor unit. It is a figure which shows the calculation cycle of the secondary signal calculated by the 37-cycle addition part. It is a graph of the primary signal D calculated by the 1-cycle addition unit. It is a graph of the secondary signal Sum (n) calculated by the 37-cycle addition unit. It is a graph of the 3rd order signal Sigma3_1 calculated by the 1st difference calculation unit. It is a graph of the 3rd order signal Sigma3_2 calculated by the 2nd difference calculation unit. It is a figure which shows the basic explanation of the unit relation value Q1 (a) and the total relation value R1 (a), and the relationship between these and a vibration frequency. When the period T _f of the target frequency f is equal to the period T _f0 of the sine wave is a diagram illustrating the position of the sixth data from the first data. When the period T _f of the target frequency f does not coincide with the period T _f0 of the sine wave is a diagram illustrating the position of the sixth data from the first data. It is a flowchart which shows the 1st frequency measurement processing by a respiratory rate measurement unit and a heart rate measurement unit. The calculation target and the calculation result of each time when the first frequency measurement process is executed are shown. It is a flowchart which shows the 2nd frequency measurement processing by a respiratory rate measurement unit and a heart rate measurement unit. The calculation target and the calculation result of each time when the second frequency measurement process is executed are shown. It is a flowchart which shows the 3rd frequency measurement processing by a respiratory rate measurement unit and a heart rate measurement unit. The calculation target and the calculation result of each time when the third frequency measurement process is executed are shown. It is a flowchart which shows the 4th frequency measurement processing by a respiratory rate measurement unit and a heart rate measurement unit. The calculation target and the calculation result of each time when the fourth frequency measurement process is executed are shown.

<1. First Embodiment>
(1-1. Configuration of biological information measurement system 1)
The configuration of the biological information measurement system 1 (hereinafter referred to as a measurement system) will be described with reference to FIGS. 1 to 3. The measurement system 1 measures the biological information of the body given to the sensor unit 10 formed in a planar shape. The measurement system 1 in the first embodiment measures the respiratory rate and the heart rate as biological information. The measurement system 1 includes a sensor unit 10, a power supply device 20, a switch circuit 40, a switching control device 50, and a vibration frequency measurement device 60.

The sensor unit 10 has flexibility and is formed in a planar shape. The sensor unit 10 can be compressed and deformed in the surface normal direction. For example, as shown in FIG. 2, the sensor unit 10 includes a first row of first electrodes 11, four rows of second electrodes 12, and a dielectric layer 13. The number of rows of the first electrode 11 and the second electrode 12 can be changed as appropriate.

The second electrode 12 is arranged in the plane normal direction of the sensor unit 10 at a distance from the first electrode 11. The second electrode 12 is formed in a band shape and is arranged parallel to each other. The extending direction of the second electrode 12 is a direction (vertical direction of FIG. 1) orthogonal to the extending direction of the first electrode 11 (horizontal direction of FIGS. 1 and 2). The dielectric layer 13 is formed in an elastically deformable planar shape and is arranged between the first electrode 11 and the second electrode 12.

The first electrode 11 and the second electrode 12 are formed by blending a conductive filler in the elastomer. The first electrode 11 and the second electrode 12 have a flexible property and have a stretchable property. Examples of the elastomer constituting the first electrode 11 and the second electrode 12 include silicone rubber, ethylene-propylene copolymer rubber, natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, and epichloro. Hydrin rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, etc. are applied. Further, the conductive filler blended in the first electrode 11 and the second electrode 12 may be any particles having conductivity, and for example, fine particles such as carbon material and metal are applied.

The dielectric layer 13 is molded from an elastomer and has a flexible and stretchable property. For example, silicone rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichlorohydrin rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber and the like are applied to the elastomer constituting the dielectric layer 13.

Therefore, the opposing positions A, B, C, and D of the first electrode 11 and the respective second electrodes 12 are located in a row. The sensor unit 10 includes a pressure sensor cell 10a (vibration sensor) that functions as a capacitance type sensor at a plurality of arranged facing positions A, B, C, and D. As described above, in the first embodiment, the sensor unit 10 includes four pressure sensor cells 10a arranged in four horizontal rows. The four pressure sensor cells 10a are arranged in a plane. When the first electrodes 11 are arranged in a plurality of rows, the positions where the first electrodes 11 and the second electrodes 12 face each other are in a matrix shape.

Then, when the sensor unit 10 receives a force of compression in the plane normal direction, the dielectric layer 13 is compressed and deformed, so that the separation distance between the first electrode 11 and the second electrode 12 becomes shorter. That is, the capacitance between the first electrode 11 and the second electrode 12 becomes large.

Here, as shown in FIG. 3, the sensor unit 10 is arranged inside, for example, in front of the seat surface 71 of the seat 70. Specifically, the sensor unit 10 is arranged on the back surface side of the skin in front of the seat surface 71. In the first embodiment, the sensor unit 10 is arranged on the seat surface 71 so that the extending direction of the second electrode 12 coincides with the front-rear direction of the seat 70. Further, the sensor unit 10 is arranged in a range corresponding to the left and right thighs. That is, the sensor unit 10 receives body pressure by the left and right thighs of the seated person. Then, the extending direction of the second electrode 12 coincides with the extending direction of the thigh portion and further, the extending direction of the femoral artery. That is, the sensor unit 10 is affected by the pulse wave of the femoral artery and the respiratory component.

The sensor unit 10 may be arranged in front of the seat surface 71 of the seat 70, behind the seat surface 71, on the back surface 72, or on the headrest 73. When the sensor unit 10 is arranged behind the seat surface, the sensor unit 10 receives body pressure from the human buttocks and is affected by arterial pulse waves and respiratory components in the human buttocks. Further, when arranged on the back surface 72, the sensor unit 10 receives body pressure from the back of the person and is affected by the pulse wave of the artery and the respiratory component in the back of the person. When the sensor unit 10 is arranged on the headrest 73, the sensor unit 10 receives body pressure from the human head and is affected by, for example, arterial pulse waves and respiratory components in the neck.

The power supply device 20 generates a predetermined voltage and applies a predetermined voltage to the first electrode 11 of the sensor unit 10. The switch circuit 40 is composed of a plurality of switches. One end of each switch is connected to the corresponding second electrode 12, and the other end of each switch is connected to a vibration frequency measuring device 60 described later. In FIG. 1, the switch corresponding to the second electrode 12 in the first row from the left side is turned on, and the others are turned off. The switching control device 50 switches ON / OFF of each switch of the switch circuit 40. Then, the switching control device 50 connects the pressure sensor cell 10a to be measured to the power supply device 20 and the vibration frequency measuring device 60.

The vibration frequency measuring device 60 acquires the detected value by the pressure sensor cell 10a to be measured, extracts the pulse wave and the respiratory component of the body facing the pressure sensor cell 10a based on the detected value, and extracts the heart rate and the respiratory rate. Is calculated. Specifically, the vibration frequency measuring device 60 acquires the change in the capacitance of the pressure sensor cell 10a for measuring the pulse wave and the respiratory component, extracts the change in the force affected by the pulse wave, and extracts the heart rate. Is calculated. Further, the vibration frequency measuring device 60 acquires the change in the capacitance of the pressure sensor cell 10a, extracts the change in the force affected by the influence of respiration, and calculates the respiratory rate.

(1-2. Configuration of vibration frequency measuring device 60)
(1-2-1. Basic configuration of vibration frequency measuring device 60)
Next, the basic configuration of the vibration frequency measuring device 60 (hereinafter, referred to as a measuring device) will be described with reference to FIG. As shown in FIG. 4, the measuring device 60 includes a filter processing unit 61 that filters the detection signal by the pressure sensor cell 10a, a respiratory rate measuring unit 62 that measures the respiratory rate based on the processed signal, and a processed signal. A heart rate measuring unit 63 that measures a heart rate based on the above is provided.

(1-2-2. Configuration of filter processing unit 61)
The filter processing unit 61 will be described with reference to FIGS. 4-FIG. 6, FIG. 7A and FIG. 7B. The filter processing unit 61 extracts a predetermined frequency range from the detection signal by the pressure sensor cell 10a. The filter processing unit 61 includes a low-pass filter, a band-pass filter, and arithmetic processing corresponding to these filter functions. Here, the heart rate per minute that can be measured by the measuring device 60 is 48 to 180, and the respiratory rate per minute that can be measured by the measuring device 60 is 6 to 27. In this case, the heart rate of 48 to 180 is 0.8 to 3.0 Hz. The respiratory rate of 6 to 27 is 0.10 to 0.45 Hz. Therefore, the filter processing unit 61 extracts a frequency range including at least 0.10 to 3.00 Hz.

First, the cycle Ta and the measurement cycle Tb of one cycle will be described with reference to FIG. The sensor unit 10 performs measurement by each of the four pressure sensor cells 10a. Specifically, the switch circuit 40 is switched to switch the pressure sensor cell 10a to be measured in the order of A → B → C → D. Therefore, the measurement cycle Tb by the same pressure sensor cell 10a is 0.25 ms. That is, the measurement frequency by the same pressure sensor cell 10a is 4 kHz.

The period Ta of one cycle is 4 ms. That is, the frequency of one cycle is 250 Hz. Therefore, in one cycle, the measurement by the same pressure sensor cell 10a is performed 16 times each. The cycle of one cycle and the measurement cycle of the same pressure sensor cell 10a can be changed as appropriate.

The filter processing unit 61 includes a 1-cycle addition unit 611, a 37-cycle addition unit 612, a first difference calculation unit 613, and a second difference calculation unit 614. The 1-cycle addition unit 611 acquires and stores the detection signal by each pressure sensor cell 10a as the primary signal D in the measurement cycle Tb (0.25 ms). The behavior of the primary signal D is shown in FIG. 7A. That is, the primary signal D contains a large amount of noise. The horizontal axis of FIG. 7A is the number of acquisitions of the primary signal D, that is, the number of samplings of the primary signal D.

Further, the 1-cycle addition unit 611 adds and stores the primary signals D of "A" to "D" for one cycle. As described above, the measurement by each pressure sensor cell 10a is performed 16 times in one cycle. Therefore, the one-cycle addition unit 611 adds the primary signal D of "A" for 16 times, and processes "B" to "D" in the same manner.

The 37-cycle adding unit 612 adds the data for one cycle obtained by the one-cycle adding unit 611 for 37 consecutive cycles. The data added for 37 cycles is stored as a secondary signal Sum (n). That is, the 37-cycle addition unit 612 adds the detection values (primary signal D) for 592 times by the pressure sensor cell 10a of "A" included in the period of 148 ms (first time length N), and adds the secondary signal Sum (primary signal D). n) is generated.

Further, the 37-cycle addition unit 612 sequentially executes the generation of the secondary signal Sum (n) while shifting by the second time interval a (a ≦ N). In the first embodiment, the second time interval a is one cycle, that is, 4 ms, but it may be a time different from one cycle. Therefore, as shown in FIG. 6, the secondary signals Sum (1), Sum (2), Sum (3), ..., Sum (n) are generated while shifting by one cycle. Then, the 37-cycle addition unit 612 similarly generates a secondary signal Sum (n) for each of the pressure sensor cells 10a of "B" to "D". In this case, the data period of the secondary signal Sum (n) is one cycle, that is, 4 ms.

The second time interval a is set to the first time length N or less, which corresponds to 37 cycles. In particular, in order to measure the pulse wave and the respiratory component with high accuracy, the second time interval a may be sufficiently shorter than the time length N corresponding to 37 cycles.

As shown in FIG. 7B, the behavior of the secondary signal Sum (n) has significantly reduced noise as compared with the primary signal D. In particular, the noise component of less than half of the measurement cycle Tb by the pressure sensor cell 10a is removed by the addition process. In the secondary signal Sum (n), the component that changes in a short period represents the change due to the pulse wave, and the vibration in the long period represents the change due to respiration. That is, the secondary signal Sum (n) is a signal representing a pulse wave and a respiratory component. Specifically, in FIG. 7B, the part marked with a circle (the part dented downward) corresponds to the pulse wave, and the part indicated by the arrow (the part greatly protruding upward) corresponds to the respiratory component. Is. That is, in a predetermined time, the number of points marked with a circle is the pulse rate, and the number of points indicated by an arrow is the respiratory rate.

The first difference calculation unit 613 and the second difference calculation unit 614 are the tertiary signal Sig3_1, which is the difference between the two secondary signals Sum (n) shifted by the third time intervals M1 and M2 (M1, M2 ≧ a). Calculate Sig3_2.

The first difference calculation unit 613 calculates the tertiary signal Sig3_1 which is the difference between the immediately preceding two secondary signals Sum (m) and Sum (m-1). That is, the tertiary signal Sig3_1 has a time interval of one cycle (equal to the second time interval a) as the third time interval M1, that is, two secondary signals Sum (m) and Sum (m-) shifted by 4 ms. It is the difference of 1).

As shown in FIG. 7C, the behavior of the tertiary signal Sig3_1 calculated by the first difference calculation unit 613 is not so different from the behavior of the secondary signal Sum (n). That is, the tertiary signal Sig3_1 is a signal representing a pulse wave and a respiratory component. Specifically, in FIG. 7C, the part marked with a circle (the part dented downward) corresponds to the pulse wave, and the part indicated by the arrow (the part greatly protruding upward) corresponds to the respiratory component. Is. Here, the absolute value of the tertiary signal Sig3_1 is smaller than that of the secondary signal Sum (n). Therefore, the tertiary signal Sig3_1 has a smaller data capacity than the secondary signal Sum (n) and can perform high-speed processing. The data cycle of the tertiary signal Sig3_1 is one cycle, that is, 4 ms.

The second difference calculation unit 614 calculates the tertiary signal Sig3_2, which is the difference between the two secondary signals Sum (m) and Sum (1) that are offset by a relatively long time. Here, the third time interval M2 is sufficiently longer than the third time interval M1 used by the first difference calculation unit 613. In the first embodiment, the third time interval M2 is 250 ms. 250 ms is one-fourth of the pulse wave, assuming that the general pulse wave is about 1 Hz. That is, the third time interval M2 is equal to a period corresponding to about half of the maximum amplitude of the pulse wave. Therefore, the difference between the two secondary signals Sum (m) and Sum (1) shifted by the third time interval M2 has a relatively large extraction effect on the influence of the pulse wave.

The behavior of the tertiary signal Sigma3_2 calculated by the second difference calculation unit 614 is as shown in FIG. 7D. In FIG. 7D, the portion marked with a circle (the portion recessed downward) corresponds to the pulse wave, and the portion indicated by the arrow (the portion largely protruding upward) corresponds to the respiratory component. Compared with the secondary signal Sum (n), the tertiary signal Sig3_2 has a remarkable change due to the pulse wave with respect to the change in respiration. Further, the tertiary signal Sig3_2 has a smaller absolute value than the secondary signal Sum (n). Therefore, the tertiary signal Sig3_1 has a smaller data capacity than the secondary signal Sum (n) and can perform high-speed processing. The data period of the tertiary signal Sig3_2 is one cycle, that is, 4 ms.

(1-2-3. Basic configuration of respiratory rate measurement unit 62 and heart rate measurement unit 63)
Next, the basic configurations of the respiratory rate measuring unit 62 and the heart rate measuring unit 63 will be described with reference to FIGS. 4, 7C and 7D. The respiratory rate measurement unit 62 acquires the tertiary signal Sig3_1 calculated by the first difference calculation unit 613 as data representing the respiratory component (FIG. 7C). Further, the respiratory rate measuring unit 62 calculates the vibration frequency caused by the respiration based on the tertiary signal Sig3_1, and obtains the respiration rate per minute.

The heart rate measurement unit 63 acquires the tertiary signal Sig3_2 calculated by the second difference calculation unit 614 as data representing the pulse wave component (FIG. 7D). Further, the heart rate measurement unit 63 calculates the vibration frequency caused by the heart rate based on the tertiary signal Sigma3_2, and obtains the heart rate per minute.

The respiratory rate measuring unit 62 and the heart rate measuring unit 63 perform substantially the same processing except that the target frequencies are different. The respiratory rate measurement unit 62 and the heart rate measurement unit 63 include a unit-related value calculation unit 621, 631, a total-related value calculation unit 622,632, and a frequency identification unit 623,633.

(1-2-4. Basic concept of unit-related values and total-related values)
Next, a basic description of the unit-related value Q1 (a) and the total-related value R1 (a), and the relationship between these and the vibration frequency will be described with reference to FIG. However, for the sake of clarity, the explanation will be made using a sine wave signal. The horizontal axis of FIG. 8 is time, and the vertical axis is amplitude.

The unit-related value Q1 (a) is calculated based on the first data at the reference time θ0 and the second data half a period (π) before the reference time θ0. In the first embodiment, the unit-related value Q1 (a) is represented by the formula (1). That is, the unit-related value Q1 (a) is the absolute value of the difference between the amplitude sin (θ0) at the reference time θ0 and the amplitude sin (θ0-π) at the time (θ0-π) half a cycle before the reference time θ0. Is. In a sine wave, the difference between the value having a phase of π / 4 and the value having a phase of 3π / 4 is the largest among the two values shifted by half a period. On the other hand, the difference between the value having a phase of 0 and the value having a phase of π / 2 is 0.

Then, the total related value R1 (a) is calculated based on a plurality of unit related values Q1 (a) having the reference time θ0 as a predetermined time. In the first embodiment, the total related value R1 (a) is represented by the formula (2). That is, the total related value R1 (a) is a value obtained by adding a plurality of unit related values Q1 (a) in which the reference time θ0 is one cycle of the frequency. Here, the total related value R1 (a) is set to the reference time θ0 for one cycle of the frequency, but may be set to half cycle, 1.5 cycle, two cycle, or the like.

Here, the unit-related value Q1 (a) was calculated based on the amplitude (first data) at the reference time θ0 and the amplitude (second data) half a period (π) before the reference time θ0. Assuming that the unit-related value Q1 is calculated based on the amplitude of the reference time θ0 and the amplitude of the reference time θ0 before a time different from the half cycle (π), the magnitude of the total related value R1 is compared and examined. To do.

The unit-related value Q1 (b) as the first comparative example is represented by the equation (3). That is, the unit-related value Q1 (b) as the first comparative example is the difference between the amplitude sin (θ0) at the reference time θ0 and the amplitude sin (θ0-π + α) before the reference time θ0 by (π−α). Is the absolute value of.

Then, the comprehensive related value R1 (b) as the first comparative example is represented by the equation (4). That is, the total related value R1 (b) as the first comparative example is a value obtained by adding a plurality of unit related values Q1 (b) in which the reference time θ0 is for one cycle of the frequency.

Further, the unit-related value Q1 (c) as the second comparative example is represented by the equation (5). That is, the unit-related value Q1 (c) as the second comparative example is the difference between the amplitude sin (θ0) at the reference time θ0 and the amplitude sin (θ0-π-β) before the reference time θ0 by (π + β). Is the absolute value of.

Then, the total related value R1 (c) as the second comparative example is represented by the formula (6). That is, the total related value R1 (c) as the second comparative example is a value obtained by adding a plurality of unit related values Q1 (c) in which the reference time θ0 is one cycle of the frequency.

The comprehensive related value R1 (a) in the first embodiment and the comprehensive related values R1 (b) and R1 (c) as comparative examples have the relationship of the formula (7). That is, the unit-related value Q1 (a) is the absolute value of the difference between the amplitude sin (θ0) at the reference time θ0 and the amplitude sin (θ0-π) at the time (θ0-π) half a cycle before the reference time θ0. Therefore, the total related value R1 (a) becomes the maximum value.

(1-2-5. Unit-related value calculation unit 621, 631)
Next, the unit-related value calculation units 621 and 631 will be described with reference to FIGS. 4, 9 and 10. The unit-related value calculation unit 621 of the respiratory rate measurement unit 62 calculates the unit-related value Q1 (n, T _f ) using the tertiary signal Sig3_1. The unit-related value calculation unit 631 of the heart rate measurement unit 63 calculates the unit-related value Q1 (n, T _f ) using the tertiary signal Sig3_2.

Then, the unit-related value calculation unit 621, 631 calculates the unit-related value Q1 (n, T _f ) for each of the plurality of target frequencies f. The unit-related value calculation unit 621 in the respiratory rate measurement unit 62 sets 0.10 to 0.45 Hz as the target frequency f. The unit-related value calculation unit 631 in the heart rate measurement unit 63 sets 0.8 to 3.0 Hz as the target frequency f.

Here, the unit-related value calculation unit 621, 631 calculates the unit-related value Q1 (n, T _f ) each time the tertiary signals Sigma3_1 and Sigma3_2 are calculated. That is, regardless of the target frequency f, the calculated frequency of the unit-related value Q1 (n, T _f ) is constant (250 Hz, period 4 ms in the first embodiment). However, the calculated frequency of the unit-related value Q1 (n, T _f ) may be changed according to the target frequency f. For example, as the target frequency f is a frequency, to increase the operation frequency of the unit associated value Q1 (n, T _f), as the target frequency f is in a low frequency, the arithmetic unit associated value Q1 (n, T _f) Reduce the frequency.

Then, the unit-related value Q1 (n, T _f ) is expressed by the equation (8). Unit related value Q1 (n, _{T f),} the first data P _(T0 n) of the reference time T0 _n, from the reference time T0 _n before a half cycle secondary data _P (T0 n -0.5T _f), reference time T0 _n from 1 cycle before the third data _P (T0 n _-T f), reference time T0 _n from 1.5 cycle before the fourth data _P (T0 n -1.5T _f), from the reference time T0 _n of 2 periods before the fifth data _P (T0 n _-2T f), is calculated on the basis of the sixth data _P of 2.5 cycle before the reference time _{T0 n (T0 n -2.5T f)} .

In other words, for the unit-related value Q1 (n, T _f ), the second data P (T0 _n −0.5 T _f ) is subtracted from the first data P (T0 _n ), and the third data P (T0 _n −) is subtracted. T _f ) is added, the fourth data P (T0 _n −1.5T _f ) is subtracted, the fifth data P (T0 _n -2T _f ) is added, and the sixth data P (T0 _n −2.5T) is added. Subtract _f ) and take the absolute value of the result. That is, the unit-related value Q1 (n, T _f ) is obtained by alternately repeating subtraction and addition every half cycle of the data.

Then, in the first embodiment, the reference time T0 _n changes in the cycle in which the tertiary signals Sig3_1 and Sig3_2 are calculated. In the first embodiment, the count value n increases by 1 every 4 ms. That is, the reference time T0 _n becomes the next calculation time each time 4 ms elapses.

Regarding the formula (8), in detail, the unit-related value Q1 (n, T _f ) is the difference between the first data and the second data, the difference between the third data and the fourth data, and the fifth data and the sixth data. It is the absolute value of the value obtained by adding the data difference. The unit-related value Q1 (n, T _f ) may be the absolute value of the difference between the first data and the second data, or the difference between the first data and the second data and the difference between the third data and the fourth data. It may be the absolute value of the value obtained by adding and.

When the period T _f of the target frequency f is equal to the period T _f0 of the sine wave, the sixth data from the first data becomes the position P shown in FIG. In this case, the first data, the third data and the fifth data, and the second data, the fourth data and the sixth data have opposite values.

On the other hand, the period T _f of the target frequency f fails to match the period T _f0 of the sine wave, the sixth data from the first data becomes the position P shown in FIG. 10. In this case, the first data, the third data and the fifth data, and the second data, the fourth data and the sixth data do not always have positive and negative values.

(1-2-6. Comprehensive related value calculation unit 622,632)
Next, the comprehensive related value calculation unit 622,632 will be described. The total related value calculation unit 622,632 uses the unit related value Q1 (n, T _f ) calculated by the unit related value calculation unit 621, 631 for each of the plurality of target frequencies f, and the total related value R1 ( Calculate T _f ). The total related value R1 (T _f ) is represented by the equation (9).

The total related value R1 (T _f ) is calculated based on a plurality of unit related values Q1 (n, T _f ) in which the reference time T0 _n is set to a predetermined time (for one cycle in the first embodiment). A total related value R1 (T _f ) will be described with reference to a specific example. In the first embodiment, the count value n increases by 1 every 4 ms. Therefore, for example, when the target frequency f is 1.0 Hz, the count value n for one cycle is 250. When the count value n _{(Tx) at} the start time Tx is 250, the time (Tx-T _f ) one cycle before is 1000 ms, and the count value n _(Tx- T _f ) one cycle before is 0. Become. Then, the value obtained by adding the unit-related value Q1 ( _250, 1.0) at the reference time T0 _{250 at} the start time Tx to the unit-related value Q1 ( ₀ , 1.0) at the reference time T00 is the total related value. It becomes R1 (1.0). The above calculation is also performed for the other target frequencies f, and the total related value R1 (T _f ) for all of the plurality of target frequencies f is obtained.

In this way, the total related value calculation unit 622 of the respiratory rate measurement unit 62 acquires the total related value R1 (T _f ) in the frequency range of 0.10 to 0.45 Hz, for example, at 0.01 Hz intervals. .. Further, the total related value calculation unit 632 of the heart rate measurement unit 63 acquires the total related value R1 (T _f ) in the frequency range of 0.8 to 3.0 Hz, for example, at 0.1 Hz intervals.

Here, as shown in FIG. 9, the total related value R1 (T _f0 ) when the period T _f of the target frequency f matches the period T _{f0 of the} sine wave, and as shown in FIG. 10, the target frequency f period _{T f} is compared with the overall associated value R1 _{(T f1)} in the case that does not match the period _{T f0} of the sine wave. In this case, as can be seen from the above equation (7), the total relation value R1 (T _f0 ) when they match and the total relation value R1 (T _f1 ) when they do not match have the relationship of the formula (10). Have.

Therefore, total related value R1 _{(T f0)} when the period _{T f} of the target frequency f is equal to the period _{T f0} of the sine wave is always a value greater than all of the total related value R1 when they do not match _{(T f1)} It becomes.

(1-2-7. Frequency identification process by frequency identification unit 623, 633)
Next, the frequency specifying process by the frequency specifying units 623 and 633 will be described. The frequency specifying units 623 and 633 determine the vibration frequency of the detection signal, specifically, the respiration frequency and the heartbeat frequency included in the detection signal, based on the total related value R1 (T _f ) of the plurality of target frequencies f. Calculate.

Multiplying the respiration frequency by 60 gives the respiration rate per minute. Also, by multiplying the heart rate frequency by 60, the heart rate per minute is obtained. That is, the frequency specifying unit 623 of the respiratory rate measuring unit 62 obtains the respiratory rate per minute by calculating the respiratory frequency. The frequency specifying unit 633 of the heart rate measuring unit 63 obtains the heart rate per minute by calculating the frequency of the heart rate.

Here, the processing by the frequency specifying units 623 and 633 is executed while being interrelated with the processing of the unit-related value calculation unit 621, 631 and the total related value calculation unit 622,632. The frequency measurement process by the unit-related value calculation unit 621, 631, the total-related value calculation unit 622, 632, and the frequency identification unit 623, 633 employs any one of the first frequency measurement process and the fourth frequency measurement process. Each frequency measurement process will be described in detail below.

(1-2-8-1. First frequency measurement processing)
The first frequency measurement process will be described with reference to FIGS. 11 and 12. However, FIGS. 11 and 12 show an example of the first frequency measurement process by the heart rate measurement unit 63. In this case, the heartbeat frequency shall be included in the range of 0.8 to 3.0 Hz. The first frequency measurement process by the respiratory rate measurement unit 62 is substantially the same.

The first frequency measurement process identifies the frequency of the heartbeat by comparing the total related values R1 (T _f ) for a part of a predetermined number of target frequencies f. Then, the first frequency measurement process calculates the total related value R1 (T _f ) for the preset start frequency, and sequentially sets the target frequency f based on the tendency of the calculated total related value R1 (T _f ). I will change it. In particular, the first frequency measurement process specifies the heartbeat frequency by starting the highest frequency among the target frequencies f and gradually lowering the target frequency f.

Further, in the first frequency measurement process, after the heartbeat frequency is once specified, the heartbeat frequency changes based on the total related value R1 (T _f ) for a predetermined number of target frequencies f including the specified frequency. Determine the tendency to do. Then, a first frequency measurement process, the latest total related value for a predetermined number of the target frequency f for continuously based on the tendency R1 (T _f) calculates the latest Overall computed related value R1 (T _f) By comparing, the frequency of the heartbeat after the change is specified.

First, the first frequency measurement process will be described with reference to FIG. As shown in FIG. 11, the unit-related value calculation unit 631 first determines the reference target frequency fc (S1 in FIG. 11). Here, the reference target frequency fc is (3.0-0.1) Hz, that is, 2.9 Hz.

Subsequently, the unit-related value calculation unit 631 sets the target frequencies f as (fc-0.1), fc, (fc + 0.1), and the unit-related values Q1 (n, T _(fc-0.1) ), Q1. (N, T _fc ) and Q1 (n, T _{(fc + 0.1)} ) are calculated (S2 in FIG. 11). Subsequently, the total related value calculation unit 632 has three total related values R1 (T _(fc-0.1) ) and R1 having target frequencies f of (fc-0.1), fc, and (fc + 0.1). (T _fc ) and R1 (T _{(fc + 0.1)} ) are calculated (S3 in FIG. 11).

Subsequently, the frequency specifying unit 633 compares the three total related values R1 (T _(fc-0.1) ), R1 (T _fc ), and R1 (T _{(fc + 0.1)} ), and acquires the magnitude relationship. (S4 in FIG. 11). When the total related value R1 (T _fc ) is the largest (S5: Y in FIG. 11), the frequency fmax of the maximum value R1 (T _fmax ) among the obtained total related values R1 (T _f ) is set. It is the vibration frequency included in the detection signal, that is, the heartbeat frequency (S9 in FIG. 11).

Subsequently, the unit-related value calculation unit 631 determines whether or not the next data P has been acquired 4 ms after the previous data P was acquired (S10 in FIG. 11). If there is no next acquired data P (S10: N in FIG. 11), it means that the time for acquiring the next data P has not been reached, that is, 4 ms has not elapsed, so that the unit-related value calculation unit 631 , Waits until the next data P is acquired. On the other hand, when there is the next acquired data P (S10: Y in FIG. 11), the unit-related value calculation unit 631 returns to S2 again and repeats the process.

In S5 of FIG. 11, when the total related value R1 (T _fc ) is not the maximum among the three acquired (S5: N in FIG. 11), the frequency specifying unit 633 compares the three total related values R1. The tendency of the vibration frequency is determined based on the result, and three consecutive target frequencies are sequentially changed based on the determined tendency.

That is, in S5 of FIG. 11, when the total related value R1 (T _fc ) is not the maximum among the three acquired (S5: N in FIG. 11), the frequency specifying unit 633 is the total related value on the high frequency side. It is determined whether or not R1 (T _{(fc + 0.1)} ) is larger than the total related value R1 (T _(fc-0.1) ) on the low frequency side (S6 in FIG. 11). When the total related value R1 (T _{(fc + 0.1)} ) on the high frequency side is larger than the total related value R1 (T _(fc-0.1) ) on the low frequency side (S6: Y in FIG. 11), the frequency is specified. The unit 633 changes the frequency (fc + 0.1) to the reference target frequency fc (S6 in FIG. 11). That is, the frequency specifying unit 633 determines that the heartbeat frequency tends to be a higher frequency based on the three total related values R1, and increases the reference target frequency fc by 0.1 Hz from the previous time. change.

After the reference target frequency fc is changed, the unit-related value calculation unit 631 continues processing from S10. That is, for the three target frequencies (fc-0.1), fc, and (fc + 0.1) including the changed reference target frequency fc, the unit-related value Q1 (n, T _f ) and the total related value R1 ( T _f ) is calculated (S2, S3).

On the other hand, in S6 of FIG. 11, when the total related value R1 (T _(fc-0.1) ) on the low frequency side is larger than the total related value R1 (T _{(fc + 0.1)} ) on the high frequency side (FIG. 11). S6: N), the frequency specifying unit 633 changes the reference target frequency (fc-0.1) to the reference target frequency fc (S8 in FIG. 11). That is, the frequency specifying unit 633 determines that the heartbeat frequency tends to be a lower frequency based on the three total related values R1, and sets the reference target frequency fc to a value 0.1 Hz smaller than the previous time. change.

After the reference target frequency fc is changed, the unit-related value calculation unit 631 continues processing from S10. That is, for the three target frequencies (fc-0.1), fc, and (fc + 0.1) including the changed reference target frequency fc, the unit-related value Q1 (n, T _f ) and the total related value R1 ( T _f ) is calculated (S2, S3).

The first frequency measurement process will be described with reference to FIG. 12 with a specific example. The heartbeat frequency of the subject shall be about 1.2 to 1.4 Hz. Here, the highest frequency of the target frequencies f, 3.0 Hz, is preset as the start frequency (S1 and S2 in FIG. 11). Then, for three consecutive (partially predetermined numbers) target frequencies f including the highest frequency of 3.0 Hz, that is, for frequencies of 2.8 Hz, 2.9 Hz, and 3.0 Hz, the unit-related value Q1 (n, T _2.8 ), Q1 (n, T _2.9 ), Q1 (n, T _3.0 ) and total related values R1 (T _2.8 ), R1 (T _2.9 ), R1 (T _{3. 0} ) is calculated (S2, S3 in FIG. 11).

Here, since the heartbeat frequency of the subject is smaller than _{2.8 to} 3.0 Hz, the total related value R1 (T _2.8 ) of the minimum target frequency of _2.8 Hz is the maximum. Become. That is, the frequency specifying unit 633 acquires the tendency that the heartbeat frequency exists in a lower frequency band. Therefore, S5: N → S6: N in FIG. 11 is obtained, and the reference target frequency fc is subtracted by 0.1 to become 2.8 Hz (S8 in FIG. 11).

When the next data P is acquired after 4 ms (S10 in FIG. 11), the unit-related value Q1 (n, for the frequency of 2.7 Hz, 2.8 Hz, 2.9 Hz) for three consecutive target frequencies f. T _2.7 ), Q1 (n, T _2.8 ), Q1 (n, T _2.9 ) and total related values R1 (T _2.7 ), R1 (T _2.8 ), R1 (T _{2. 9} ) is calculated (S2, S3 in FIG. 11). Since the heartbeat frequency of the subject is smaller than _{2.7 to 2.9} Hz, the minimum overall related value R1 (T _2.7 ) of the target frequency of _2.7 Hz is the maximum. Therefore, S5: N → S6: N in FIG. 11 is obtained again, and the reference target frequency fc is subtracted by 0.1 to become 2.7 Hz (S8 in FIG. 11).

This process is repeated several times, and after 64 ms has elapsed from the start, the unit-related value Q1 (n, T _1.2) is used for three consecutive target frequencies f, that is, for frequencies of _1.2 Hz, 1.3 Hz, and 1.4 Hz. ), Q1 (n, T _1.3 ), Q1 (n, T _1.4 ) and the total related values R1 (T _1.2 ), R1 (T _1.3 ), R1 (T _1.4 ) are calculated. (S2 and S3 in FIG. 11). Among these, the minimum target frequency _1.2 Hz, the total related value R1 (T _1.2 ) is the maximum. Therefore, again, S5: N → S6: N in FIG. 11 is obtained, and the reference target frequency fc is subtracted by 0.1 to become 1.2 Hz (S8 in FIG. 11).

Then, 68 ms after the start of processing, the unit-related values Q1 (n, T _1.1 ) and Q1 (n) are used for three consecutive target frequencies f, that is, for frequencies of _1.1 Hz, 1.2 Hz, and 1.3 Hz. , T _1.2 ), Q1 (n, T _1.3 ) and the total related values R1 (T _1.1 ), R1 (T _1.2 ), R1 (T _1.3 ) are calculated (Fig. 11). S2, S3). Among these, the total related value R1 (T _1.2 ) of the central target frequency of _1.2 Hz is the largest. Then, S5: Y in FIG. 11 is obtained, and the frequency specifying unit 633 specifies the frequency fmax of the total related value R1 (T _1.2 ), which is the maximum value, as the heartbeat frequency. Since the heartbeat frequency is 1.2 Hz, the heart rate per minute is 72 times. In addition, in FIG. 12, what is marked with a frame in the number of time on the horizontal axis means the timing when the frequency of the heartbeat is specified.

Even after the heart rate frequency is once specified, the heart rate measuring unit 63 continues to measure the heart rate frequency and continues to measure the change in the heart rate frequency. That is, when the next data P is acquired, that is, 72 ms after the start of processing, the unit-related value Q1 (n, T ₁₎ is obtained for the same target frequencies of 1.1 Hz, 1.2 Hz, and 1.3 Hz as the previous time. _.1 ), Q1 (n, T _1.2 ), and Q1 (n, T _1.3 ) are calculated (S2 in FIG. 11). Here, the first data P (T0 _{n (Tx)} ) at the present time (start time Tx) is newly acquired. Therefore, in each of the unit-related values Q1 (n, T _1.1 ), Q1 (n, T _1.2 ), and Q1 (n, T _1.3 ), the count value n is the current count (start time Tx). The calculation is performed only for the value n _(Tx) . That is, when the count value n is a count value other than the current time (start time Tx), the calculation has already been performed. Therefore, the amount of calculation is very small.

Subsequently, the total related values R1 (T _1.1 ), R1 (T _1.2 ), and R1 (T _1.3 ) are calculated (S3 in FIG. 11). Among these, the total related value R1 (T _1.3 ) having the maximum target frequency of _1.3 Hz is the maximum. That is, the frequency specifying unit 633 acquires the tendency that the heartbeat frequency exists in a higher frequency band. Therefore, S5: N → S6: Y in FIG. 11 is obtained again, and the reference target frequency fc is added by 0.1 to become 1.3 Hz (S7 in FIG. 11).

Then, after 76 ms have elapsed from the start of processing, the unit-related values Q1 (n, T _1.2 ) and Q1 (n) are used for three consecutive target frequencies f, that is, for frequencies of _1.2 Hz, 1.3 Hz, and 1.4 Hz. , T _1.3 ), Q1 (n, T _1.4 ) and the total related values R1 (T _1.2 ), R1 (T _1.3 ), R1 (T _1.4 ) are calculated (Fig. 11). S2, S3). Among these, the total related value R1 (T _1.3 ) of the central target frequency of _1.3 Hz is the largest. Then, S5: Y in FIG. 11 is obtained, and the frequency specifying unit 633 specifies the frequency fmax of the total related value R1 (T _1.3 ), which is the maximum value, as the heartbeat frequency. In this case, since the heartbeat frequency is 1.3 Hz, the heart rate per minute is 78 times. In this way, each time the data P is acquired, the above process is repeated, and when the heartbeat frequency changes, the current heartbeat frequency can be specified.

In the above process, once the heartbeat frequency is specified, the heartbeat frequency is specified when the total related value R1 (T _fc ) of the central target frequency fc is maximized among the three. I decided. Not limited to this, once the heartbeat frequency is specified, even if the total related value R1 (T _fc ) of the central target frequency fc does not become the maximum among the three, among the three It may be specified that the target frequency f corresponding to the maximum total related value R1 is the frequency of the heartbeat.

(1-2-8-2. Second frequency measurement processing)
The second frequency measurement process will be described with reference to FIGS. 13 and 14. However, FIGS. 13 and 14 take the second frequency measurement process by the heart rate measurement unit 63 as an example. The second frequency measurement process by the respiratory rate measurement unit 62 is substantially the same.

The second frequency measurement process identifies the frequency of the heartbeat by comparing the total related values R1 (T _f ) for a part of a predetermined number of target frequencies f. Then, the second frequency measurement process calculates the total related value R1 (T _f ) for the preset start frequency, and sequentially sets the target frequency f based on the tendency of the calculated total related value R1 (T _f ). I will change it. In particular, the second frequency measurement process specifies the heartbeat frequency by starting the lowest frequency among the target frequencies f and gradually increasing the target frequency f.

Further, the second frequency measurement process determines the tendency of the heartbeat frequency to change based on the total related value R1 for a predetermined number of target frequencies including the specified frequency after the heartbeat frequency is once specified. .. Then, in the second frequency measurement process, the latest total related value R1 (T _f ) for a predetermined number of continuous target frequencies f is calculated based on the tendency, and the calculated latest total related value R1 is compared. So, I try to specify the frequency of the heartbeat after the change.

First, the second frequency measurement process will be described with reference to FIG. As shown in FIG. 13, the unit-related value calculation unit 631 first determines the reference target frequency fc (S11 in FIG. 13). Here, the reference target frequency fc is (0.8 + 0.1) Hz, that is, 0.9 Hz.

Subsequently, the unit-related value calculation unit 631 sets the target frequencies f as (fc-0.1), fc, (fc + 0.1), and the unit-related values Q1 (n, T _(fc-0.1) ), Q1. (N, T _fc ) and Q1 (n, T _{(fc + 0.1)} ) are calculated (S12 in FIG. 11). Subsequently, the total related value calculation unit 632 has three total related values R1 (T _(fc-0.1) ) and R1 having target frequencies f of (fc-0.1), fc, and (fc + 0.1). (T _fc ) and R1 (T _{(fc + 0.1)} ) are calculated (S13 in FIG. 13).

Subsequently, the frequency specifying unit 633 compares the three total related values R1 (T _(fc-0.1) ), R1 (T _fc ), and R1 (T _{(fc + 0.1)} ), and acquires the magnitude relationship. (S14 in FIG. 13). Then, when the total related value R1 (T _fc ) is the largest (S15: Y in FIG. 13), the frequency fmax of the maximum value R1 (T _fmax ) among the obtained total related values R1 (T _f ) is obtained. Is the vibration frequency included in the detection signal, that is, the heartbeat frequency (S19 in FIG. 13).

Subsequently, the unit-related value calculation unit 631 determines whether or not the next data P has been acquired 4 ms after the previous data P was acquired (S20 in FIG. 13). If there is no next acquired data P (S20: N in FIG. 13), it means that the time for acquiring the next data P has not been reached, that is, 4 ms has not elapsed, so that the unit-related value calculation unit 631 , Waits until the next data P is acquired. On the other hand, when there is the next acquired data P (S20: Y in FIG. 13), the unit-related value calculation unit 631 returns to S12 again and repeats the process.

In S14 of FIG. 13, when the total related value R1 (T _fc ) is not the maximum among the three acquired (S14: N in FIG. 13), the vibration frequency is based on the comparison result of the three total related values R1. Is acquired, and three consecutive target frequencies are sequentially changed based on the tendency.

That is, in S15 of FIG. 13, when the total related value R1 (T _fc ) is not the maximum among the three acquired (S15: N in FIG. 13), the frequency specifying unit 633 is the total related value on the high frequency side. It is determined whether or not R1 (T _{(fc + 0.1)} ) is larger than the total related value R1 (T _(fc-0.1) ) on the low frequency side (S16 in FIG. 13). When the total related value R1 (T _{(fc + 0.1)} ) on the high frequency side is larger than the total related value R1 (T _(fc-0.1) ) on the low frequency side (S16: Y in FIG. 13), the frequency is specified. The unit 633 changes the frequency (fc + 0.1) to the reference target frequency fc (S17 in FIG. 13). That is, the frequency specifying unit 633 determines that the heartbeat frequency tends to be a higher frequency based on the three total related values R1 (n, T _f ), and sets the reference target frequency fc from the previous time. Change to a value that is 0.1 Hz larger.

After the reference target frequency fc is changed, the unit-related value calculation unit 631 continues processing from S20. That is, for the three target frequencies (fc-0.1), fc, and (fc + 0.1) including the changed reference target frequency fc, the unit related value Q1 (n, T _f ) and the total related value R1 ( T _f ) is calculated (S12, S13).

On the other hand, in S16 of FIG. 13, when the total related value R1 (T _(fc-0.1) ) on the low frequency side is larger than the total related value R1 (T _{(fc + 0.1)} ) on the high frequency side (FIG. 13). S16: N), the frequency specifying unit 633 changes the frequency (fc-0.1) to the reference target frequency fc (S18 in FIG. 11). That is, the frequency specifying unit 633 determines that the heartbeat frequency tends to be a lower frequency based on the three total related values R1, and sets the reference target frequency fc to a value 0.1 Hz smaller than the previous time. change.

After the reference target frequency fc is changed, the unit-related value calculation unit 631 continues processing from S20. That is, for the three target frequencies (fc-0.1), fc, and (fc + 0.1) including the changed reference target frequency fc, the unit related value Q1 (n, T _f ) and the total related value R1 ( T _f ) is calculated (S12, S13).

The second frequency measurement process will be described with reference to FIG. 14 with a specific example. The heartbeat frequency of the subject shall be about 1.2 to 1.4 Hz. Here, the lowest frequency 0.8 Hz of the target frequencies f is preset as the start frequency (S11 and S12 in FIG. 13). Then, for three consecutive (partially predetermined numbers) target frequencies f including the lowest frequency 0.8 Hz, that is, for frequencies of 0.8 Hz, 0.9 Hz, and 1.0 Hz, the unit-related value Q1 (n, T _0.8 ), Q1 (n, T _0.9 ), Q1 (n, T _1.0 ) and overall related values R1 (T _0.8 ), R1 (T _0.9 ), R1 (T _{1. 0} ) is calculated (S12, S13 in FIG. 13).

Here, since the heartbeat frequency of the subject is higher than 0.8 to 1.0 Hz, the total related value R1 (T _1.0 ) of the maximum target frequency of 1.0 Hz is the maximum. Become. That is, the frequency specifying unit 633 acquires the tendency that the heartbeat frequency exists in a higher frequency band. Therefore, S15: N → S16: Y in FIG. 13 is obtained, and the reference target frequency fc is added by 0.1 to become 1.0 Hz (S17 in FIG. 13).

The process is repeated, and 12 ms after the start of the process, the unit-related value Q1 (n, T _1.1 ), for three consecutive target frequencies f, that is, for frequencies of _1.1 Hz, 1.2 Hz, and 1.3 Hz. Q1 (n, T _1.2 ), Q1 (n, T _1.3 ) and the total related values R1 (T _1.1 ), R1 (T _1.2 ), R1 (T _1.3 ) are calculated. (S12, S13 in FIG. 13). Among these, the total related value R1 (T _1.2 ) of the central target frequency of _1.2 Hz is the largest.

Then, S15: Y in FIG. 13 is obtained, and the frequency _1.2 Hz of the total related value R1 (T _1.2 ), which is the maximum value, is specified as the heartbeat frequency. Since the heartbeat frequency is 1.2 Hz, the heart rate per minute is 72 times. In addition, in FIG. 14, what is marked with a frame in the number of time on the horizontal axis means the timing when the frequency of the heartbeat is specified.

Even after the heart rate frequency is once specified, the heart rate measuring unit 63 continues to measure the heart rate frequency and continues to measure the change in the heart rate frequency. That is, every time the data P is acquired, the above process is repeated, and when the heartbeat frequency changes, the current heartbeat frequency can be specified.

In the above process, once the heartbeat frequency is specified, the heartbeat frequency is specified when the total related value R1 (T _fc ) of the central target frequency fc is maximized among the three. I decided. Not limited to this, once the heartbeat frequency is specified, even if the total related value R1 (T _fc ) of the central target frequency fc does not become the maximum among the three, among the three It may be specified that the target frequency f corresponding to the maximum total related value R1 is the frequency of the heartbeat.

(1-2-8-3. Third frequency measurement processing)
The third frequency measurement process will be described with reference to FIGS. 15 and 16. However, FIGS. 15 and 16 take as an example the third frequency measurement process by the heart rate measurement unit 63. The third frequency measurement process by the respiratory rate measurement unit 62 is substantially the same.

Third frequency measurement process, first, all units associated value Q1 (n, _{T f)} of the target frequency f and overall associated value R1 _{(T f)} computes, computed total related value R1 to _{(T f)} The frequency of the heartbeat is identified by comparison. Further, in the third frequency measurement process, after the heartbeat frequency is once specified, the total related value R1 for a part of a predetermined number of frequencies including the specified frequency is calculated, and the calculated total related value R1 ( By comparing T _f ), the frequency of the heartbeat after the change is specified.

First, the third frequency measurement process will be described with reference to FIG. As shown in FIG. 15, the unit-related value calculation unit 631 calculates the unit-related value Q1 (n, T _f ) for all the target frequencies f of 0.8 to 3.0 Hz (S21 in FIG. 15). Subsequently, the total related value calculation unit 632 calculates the total related value R1 (T _f ) for all the target frequencies f of 0.8 to 3.0 Hz (S22 in FIG. 15).

Subsequently, the frequency specifying unit 633 compares all the acquired total related values R1 (T _f ) and acquires the magnitude relationship (S23 in FIG. 15). Then, the frequency specifying unit 633 sets the frequency fmax of the maximum value R1 (T _fmax ) among the obtained total related values R1 (T _f ) as the heartbeat frequency (S24 in FIG. 15). In this way, the heartbeat frequency is once specified. Subsequently, the frequency specifying unit 633 sets the frequency fmax, which is the frequency of the heartbeat, to the reference target frequency fc (S25 in FIG. 15).

Subsequently, the unit-related value calculation unit 631 determines whether or not the next data P has been acquired 4 ms after the previous data P was acquired (S26 in FIG. 15). If there is no next acquired data P (S26: N in FIG. 15), it means that the time for acquiring the next data P has not been reached, that is, 4 ms has not elapsed, so that the unit-related value calculation unit 631 , Waits until the next data P is acquired.

On the other hand, when there is the next acquired data P (S26: Y in FIG. 15), the unit-related value calculation unit 631 sets the target frequencies f to (fc-0.1), fc, and (fc + 0.1). The unit-related values Q1 (n, T _(fc-0.1) ), Q1 (n, T _fc ), and Q1 (n, T _{(fc + 0.1)} ) are calculated (S27 in FIG. 15). That is, in the third frequency measurement process, the unit-related values Q1 (n, T _f ) were initially calculated for all the target frequencies f, but once the heartbeat frequency is specified, some target frequencies f. The unit-related value Q1 (n, T _f ) is calculated for.

Subsequently, the total related value calculation unit 632 has three total related values R1 (T _(fc-0.1) ) and R1 having target frequencies f of (fc-0.1), fc, and (fc + 0.1). (T _fc ) and R1 (T _{(fc + 0.1)} ) are calculated (S28 in FIG. 15). Subsequently, the process returns to S23 and the process is repeated. That is, the frequency specifying unit 633 compares the acquired three total related values R1 (T _(fc-0.1) ), R1 (T _fc ), and R1 (T _{(fc + 0.1)} ), and determines the magnitude relationship. Acquire (S23 in FIG. 15). Then, the frequency specifying unit 633 has a maximum value R1 (T _fmax ) among the three total related values R1 (T _(fc-0.1) ), R1 (T _fc ), and R1 (T _{(fc + 0.1)} ). The frequency fmax of is taken as the frequency of the heartbeat (S24 in FIG. 15).

The third frequency measurement process will be described with reference to FIG. 16 with a specific example. The unit-related value Q1 (n, T _f ) and the total related value R1 (T _f ) are calculated for all frequencies from 0.8 to 3.0 Hz (S21, S22 in FIG. 15). Among these, the total related value R1 (T _1.2 ) for the frequency of _1.2 Hz is the largest. Therefore, the frequency _1.2 Hz of the total related value R1 (T _1.2 ), which is the maximum value, is specified as the heartbeat frequency (S24 in FIG. 15).

At this time, the specified heartbeat frequency fmax is set to the reference target frequency fc. Therefore, next, for frequencies of _1.1 Hz, 1.2 Hz, and 1.3 Hz, the unit-related values Q1 (n, T _1.1 ), Q1 (n, T _1.2 ), and Q1 (n, T _{1. 3} ) and the total related values R1 (T _1.1 ), R1 (T _1.2 ), and R1 (T _1.3 ) are calculated (S27, S28 in FIG. 15). At this time, when the total related value R1 (T _1.3 ) reaches the maximum value, the heartbeat frequency is set to _1.3 Hz at this point (S24 in FIG. 15). The above process is sequentially repeated to obtain changes in the current heartbeat frequency and the past heartbeat frequencies.

(1-2-8-4. Fourth frequency measurement processing)
The fourth frequency measurement process will be described with reference to FIGS. 17 and 18. However, FIGS. 17 and 18 show an example of the fourth frequency measurement process by the heart rate measurement unit 63. The fourth frequency measurement process by the respiratory rate measurement unit 62 is substantially the same.

Fourth frequency measurement process, first, all units associated value Q1 (n, _{T f)} of the target frequency f and overall associated value R1 _{(T f)} computes, computed total related value R1 to _{(T f)} The frequency of the heartbeat is identified by comparison. Further, in the third frequency measurement process, after the heartbeat frequency is once specified, the heartbeat frequency tends to change based on the total related value R1 for a part of a predetermined number of frequencies including the specified frequency. To determine. The fourth frequency measurement process, the latest total related value for a predetermined number of the target frequency f for continuously based on the tendency R1 (T _f) calculates the latest Overall computed related value R1 (T _f) By comparing, the frequency of the heartbeat after the change is specified.

First, the fourth frequency measurement process will be described with reference to FIG. As shown in FIG. 17, the unit-related value calculation unit 631 calculates the unit-related value Q1 (n, T _f ) for all the target frequencies f of 0.8 to 3.0 Hz (S31 in FIG. 17). Subsequently, the total related value calculation unit 632 calculates the total related value R1 (T _f ) for all the target frequencies f of 0.8 to 3.0 Hz (S32 in FIG. 17).

Subsequently, the frequency specifying unit 633 compares all the acquired total related values R1 (T _f ) and acquires the magnitude relationship (S33 in FIG. 17). Then, the frequency specifying unit 633 sets the frequency fmax of the maximum value R1 (T _fmax ) among the obtained total related values R1 (T _f ) as the heartbeat frequency (S34 in FIG. 17). In this way, the heartbeat frequency is once specified.

Subsequently, the frequency specifying unit 633 temporarily sets the frequency fmax, which is the frequency of the heartbeat, to the reference target frequency fc. Then, the tendency of the vibration frequency is acquired by using the three total related values R1 (T _fc ) for the reference target frequency fc and the frequencies fc-0.1 and fc + 0.1 before and after the reference frequency fc, and based on the tendency. Three consecutive target frequencies for calculation are sequentially changed.

That is, in S36 of FIG. 17, the frequency specifying unit 633 has a total related value R1 (T _{(fc + 0.1)} ) on the high frequency side of the reference target frequency fc, which is one low frequency side. It is determined whether or not it is larger than T _(fc-0.1) ) (S36 in FIG. 17). When the total related value R1 (T _{(fc + 0.1)} ) on the high frequency side is larger than the total related value R1 (T _(fc-0.1) ) on the low frequency side (S36: Y in FIG. 17), the frequency is specified. The unit 633 changes the frequency (fc + 0.1) to the reference target frequency fc (S37 in FIG. 17). That is, the frequency specifying unit 633 determines that the heartbeat frequency tends (possibly) to change to the high frequency side based on the three total related values R1 (n, T _f ), and determines that the target frequency fc as a reference. Is changed to a value 0.1 Hz larger than the previous time.

On the other hand, when the total related value R1 (T _(fc-0.1) ) on the low frequency side is larger than the total related value R1 (T _{(fc + 0.1)} ) on the high frequency side (S36: N in FIG. 17), The frequency specifying unit 633 changes the frequency (fc-0.1) to the reference target frequency fc (S38 in FIG. 17). That is, the frequency specifying unit 633 determines that the heartbeat frequency tends (possibly) to change to the low frequency side based on the three total related values R1 (n, T _f ), and determines that the target frequency becomes a reference. Change fc to a value 0.1Hz smaller than the previous time.

Subsequently, the unit-related value calculation unit 631 determines whether or not the next data P has been acquired 4 ms after the previous data P was acquired (S39 in FIG. 17). If there is no next acquired data P (S39: N in FIG. 17), it means that the time for acquiring the next data P has not been reached, that is, 4 ms has not elapsed, so that the unit-related value calculation unit 631 , Waits until the next data P is acquired.

On the other hand, when there is the next acquired data P (S39: Y in FIG. 17), the unit-related value calculation unit 631 sets the target frequencies f to (fc-0.1), fc, and (fc + 0.1). The unit-related values Q1 (n, T _(fc-0.1) ), Q1 (n, T _fc ), and Q1 (n, T _{(fc + 0.1)} ) are calculated (S40 in FIG. 17). That is, in the fourth frequency measurement process, the unit-related values Q1 (n, T _f ) were initially calculated for all the target frequencies f, but once the heartbeat frequency is specified, some target frequencies f. The unit-related value Q1 (n, T _f ) is calculated for.

At this time, the reference target frequency fc is not the frequency specified as the heartbeat frequency, but one of the frequencies before and after that. That is, in order to reliably follow the change in the heartbeat, the frequency specified as the frequency of the heartbeat is not set to the center frequency of the three to be calculated next, but one of the frequencies before and after the frequency is calculated next. The frequency is the center of the three.

Subsequently, the total related value calculation unit 632 has three total related values R1 (T _(fc-0.1) ) and R1 having target frequencies f of (fc-0.1), fc, and (fc + 0.1). (T _fc ) and R1 (T _{(fc + 0.1)} ) are calculated (S41 in FIG. 17).

Subsequently, the frequency specifying unit 633 compares the acquired three total related values R1 (T _(fc-0.1) ), R1 (T _fc ), and R1 (T _{(fc + 0.1)} ), and has a magnitude relationship. (S42 in FIG. 17). Then, the frequency specifying unit 633 has a maximum value R1 (T _fmax ) among the three total related values R1 (T _(fc-0.1) ), R1 (T _fc ), and R1 (T _{(fc + 0.1)} ). The frequency fmax of is taken as the frequency of the heartbeat (S43 in FIG. 17). Subsequently, the process returns to S36 and the process is repeated.

The fourth frequency measurement process will be described with reference to FIG. 18 with a specific example. The unit-related value Q1 (n, T _f ) and the total related value R1 (T _f ) are calculated for all frequencies from 0.8 to 3.0 Hz (S31, S32 in FIG. 17). Among these, the total related value R1 (T _1.2 ) for the frequency of _1.2 Hz is the largest. Therefore, the frequency _1.2 Hz of the total related value R1 (T _1.2 ), which is the maximum value, is specified as the heartbeat frequency (S34 in FIG. 17).

At this time, the specified heartbeat frequency fmax is set to the reference target frequency fc. Then, the comprehensive related values R1 (T _1.1 ) and R1 (T _1.3 ) for the frequencies before and after the reference target frequency fc (1.2 Hz) are compared (S36 in FIG. 17). Since the total related value R1 (T _1.3 ) of _1.3 Hz is larger, the frequency specifying unit 633 determines that the heartbeat frequency tends to change to a higher frequency side than 1.2 Hz.

Therefore, after 4 ms have elapsed from the start of processing, the unit-related values Q1 (n, T _1.2 ), for the three consecutive target frequencies 1.2 Hz, 1.3 Hz, and 1.4 Hz centered on 1.3 Hz, are set. Q1 (n, T _1.3 ), Q1 (n, T _1.4 ) and the total related values R1 (T _1.2 ), R1 (T _1.3 ), R1 (T _1.4 ) are calculated. (S40, S41 in FIG. 17). Among these, the total related value R1 (T _1.2 ) of _1.2 Hz is the largest. Then, even at the present time, the heartbeat frequency is set to 1.2 Hz.

At this time, among the three frequencies, the total related value R1 (T _1.4 ) of the high frequency side frequency 1.4 Hz and the total related value R1 (T _1.2 ) of the low frequency side frequency _1.2 Hz are set. By comparison, the _1.2 Hz overall related value R1 (T _1.2 ) is larger (S36 in FIG. 17).

Therefore, after 8 ms has elapsed from the start of processing, the unit-related value Q1 (n, T _1.1 ) is used for three consecutive target frequencies of 1.1 Hz, 1.2 Hz, and 1.3 Hz centered on 1.2 Hz. , Q1 (n, T _1.2 ), Q1 (n, T _1.3 ) and the total related values R1 (T _1.1 ), R1 (T _1.2 ), R1 (T _1.3 ) are calculated. (S40, S41 in FIG. 17). The above process is sequentially repeated to obtain changes in the current heartbeat frequency and the past heartbeat frequencies.

<2. Second Embodiment>
The biological information measurement system 1 of the second embodiment will be described. In the biometric information measurement system 1 of the second embodiment, the unit-related value Q2 (n, _Tf ) and the total related value R2 ( _Tf ) are different from those of the biometric information measurement system 1 of the first embodiment. The differences will be described below.

(2-1. Basic concept of unit-related values and total-related values)
A basic description of the unit-related value Q2 (a) and the total-related value R2 (a), and the relationship between these and the vibration frequency will be described with reference to FIG.

The unit-related value Q2 (a) is calculated based on the first data at the reference time θ0 and the second data half a cycle (π) before the reference time θ0. In the second embodiment, the unit-related value Q2 (a) is represented by the formula (11). That is, the unit-related value Q2 (a) is the absolute value of the amplitude sin (θ0) at the reference time θ0 and the absolute value of the amplitude sin (θ0-π) at the time (θ0-π) half a cycle before the reference time θ0. Is the added value of. In a sine wave, the absolute value having a phase of π / 4 and the absolute value having a phase of 3π / 4 are the largest of the two values that are offset by half a period. On the other hand, the absolute value having a phase of 0 and the absolute value having a phase of π / 2 are 0.

Then, the total related value R2 (a) is calculated based on a plurality of unit related values Q2 (a) having the reference time θ0 as a predetermined time. In the second embodiment, the total related value R2 (a) is represented by the formula (12). That is, the total related value R2 (a) is a value obtained by adding a plurality of unit related values Q2 (a) in which the reference time θ0 is one cycle of the frequency. Here, the total related value R2 (a) is set to the reference time θ0 for one cycle of the frequency, but may be set to half cycle, 1.5 cycle, two cycle, or the like.

Here, the unit-related value Q2 (a) was calculated based on the amplitude (first data) at the reference time θ0 and the amplitude (second data) half a period (π) before the reference time θ0. Assuming that the unit-related value Q2 is calculated based on the amplitude of the reference time θ0 and the amplitude of the reference time θ0 before a time different from the half cycle (π), the magnitude of the total related value R2 is compared and examined. To do.

The unit-related value Q2 (b) as the first comparative example is represented by the equation (13). That is, the unit-related value Q2 (b) as the first comparative example is the absolute value of the amplitude sin (θ0) at the reference time θ0 and the amplitude sin (θ0-π + α) before the reference time θ0 by (π−α). It is an addition value with the absolute value of.

Then, the total related value R2 (b) as the first comparative example is represented by the equation (14). That is, the total related value R2 (b) as the first comparative example is a value obtained by adding a plurality of unit related values Q2 (b) in which the reference time θ0 is one cycle of the frequency.

Further, the unit-related value Q2 (c) as the second comparative example is represented by the equation (15). That is, the unit-related value Q2 (c) as the second comparative example is the absolute value of the amplitude sin (θ0) at the reference time θ0 and the amplitude sin (θ0-π-β) before the reference time θ0 by (π + β). It is an addition value with the absolute value of.

Then, the total related value R2 (c) as the second comparative example is represented by the formula (16). That is, the total related value R2 (c) as the second comparative example is a value obtained by adding a plurality of unit related values Q2 (c) in which the reference time θ0 is one cycle of the frequency.

The comprehensive related value R2 (a) in the second embodiment and the comprehensive related values R2 (b) and R1 (c) as comparative examples have the relationship of the formula (17). That is, the unit-related value Q2 (a) is the absolute value of the amplitude sin (θ0) at the reference time θ0 and the absolute value of the amplitude sin (θ0-π) at the time (θ0-π) half a cycle before the reference time θ0. By adding the value to and, the total related value R2 (a) becomes the maximum value.

(2-2. Unit-related value calculation unit 621, 631)
Next, the unit-related value calculation units 621 and 631 will be described. The unit-related value calculation unit 621 of the respiratory rate measurement unit 62 calculates the unit-related value Q2 (n, T _f ) using the tertiary signal Sig3_1. The unit-related value calculation unit 631 of the heart rate measurement unit 63 calculates the unit-related value Q2 (n, T _f ) using the tertiary signal Sig3_2.

The unit-related value Q2 (n, T _f ) is represented by the equation (18). Unit related value Q2 (n, _{T f),} the first data P of the reference time _{T0 n} (T0 _n), from the reference time T0 _n before a half cycle secondary data _P (T0 n -0.5T _f), reference time T0 _n from 1 cycle before the third data _P (T0 n _-T f), reference time T0 _n from 1.5 cycle before the fourth data _P (T0 n -1.5T _f), from the reference time T0 _n of 2 periods before the fifth data _P (T0 n _-2T f), is calculated on the basis of the sixth data _P of 2.5 cycle before the reference time _{T0 n (T0 n -2.5T f)} .

In other words, the unit-related value Q2 (n, T _f ) is the absolute value of the first data P (T0 _n ), the absolute value of the second data P (T0 _n −0.5 T _f ), and the third data P (T0). The absolute value of _n −T _f ), the absolute value of the fourth data P (T0 _n −1.5T _f ), the absolute value of the fifth data P (T0 _{n −} 2T _f ), and the sixth data P (T0 _n). Take the value obtained by adding the absolute value of -2.5T _f ). That is, the unit-related value Q2 (n, T _f ) is obtained by adding the absolute value of the data for each half cycle of the data.

Then, in the second embodiment, the reference time T0 _n changes in the cycle in which the tertiary signals Sig3_1 and Sig3_2 are calculated. In the second embodiment, the count value n increases by 1 every 4 ms. That is, the reference time T0 _n becomes the next calculation time each time 4 ms elapses.

Regarding equation (18), in detail, the unit-related value Q2 (n, T _f ) is the absolute value of each of the first data, the second data, the third data, the fourth data, the fifth data, and the sixth data. Is the value obtained by adding. The unit-related value Q2 (n, T _f ) may be the sum of the absolute values of the first data and the second data, or the first data, the second data, the third data, and the fourth data. It may be a value obtained by adding the absolute values of each of.

(2-3. Comprehensive related value calculation unit 622,632)
Next, the comprehensive related value calculation unit 622,632 will be described. The total related value calculation unit 622,632 uses the unit related value Q2 (n, T _f ) calculated by the unit related value calculation unit 621, 631 for each of the plurality of target frequencies f, and the total related value R2 ( Calculate T _f ). The total related value R2 (T _f ) is represented by the equation (19).

The total related value R2 (T _f ) is calculated based on a plurality of unit related values Q2 (n, T _f ) in which the reference time T0 _n is set to a predetermined time (for one cycle in the second embodiment). The total related value R2 (T _f ) is basically the same as the total related value R1 (T _f ) of the first embodiment.

As shown in FIG. 9, the total related value R2 (T _f0 ) when the period T _f of the target frequency f matches the period T _{f0 of the} sine wave, and as shown in FIG. 10, the period T _f of the target frequency _f. Compares with the total relevance value R2 (T _f1 ) when does not match the period T _{f0 of the} sine wave. In this case, as can be seen from the above equation (17), the relationship between the total related value R2 (T _f0 ) when they match and the total related value R2 (T _f1 ) when they do not match is the relationship of the formula (20). Have.

Therefore, total related value R2 _{(T f0)} when the period _{T f} of the target frequency f is equal to the period _{T f0} of the sine wave is always a value greater than all of the total related values when they do not match R2 _{(T f1)} It becomes. From the relationship of the equation (20), as described in the first embodiment, the respiratory rate and the heart rate per minute are measured by similarly executing the first frequency measurement process to the fourth frequency measurement process. be able to.

(3. Others)
In the first embodiment and the second embodiment, the unit-related value calculation unit 621, 631 uses the unit-related values Q1 (n, T _f ), Q2 (, using each data P itself which is the tertiary signals Sigma3_1 and Sigma3_2 themselves. n, T _f ) was calculated. In addition to this, the unit-related value calculation unit 621, 631 may calculate the unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) using the correlation value of each data P. ..

For example, the correlation value of the first data P (T0 _n), a power value of the first data P (T0 _n), the integrated value of the predetermined value of the first data P (T0 _n), and the like. The correlation value of the second data _P (T0 n -0.5T _f), a power value of the second data _P (T0 n -0.5T _f), the second data _P (T0 n -0.5T _f) It is a value obtained by integrating predetermined values. The same applies to other data. Then, the unit-related value calculation unit 621, 631 replaces each data P with the correlation value of each data in the equations (8) and (18), and the unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) may be calculated.

(4. Effect of the embodiment)
The vibration frequency measuring device 60 of the first embodiment and the second embodiment measures the frequency of vibration included in the detection signal of the vibration sensor (10a). The measuring device 60 has a filter processing unit 61 that extracts a predetermined frequency range from the detection signal, and the first data P of the reference time T0 _n for a plurality of target frequencies f with respect to the processed signals processed by the filter processing unit 61. (T0 _n) and unit associated value _Q1 from the reference time T0 _n based on the previous half cycle secondary data _{P (T0 n -0.5T f) (} n, T f), calculates the Q2 (n, _{T f)} Unit-related value calculation unit 621, 631 and a plurality of unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) with a reference time T0 _n as a predetermined time for a plurality of target frequencies f. Te, total related value _R1 (T f), R2 and total related value calculating unit 622 and 632 for calculating the _{(T f),} total related values of the plurality of target frequency f _R1 (T f), the R2 _{(T f)} Based on this, a frequency specifying unit 623 and 633 for specifying the vibration frequency of the detection signal is provided.

According to the measurement device 60, the unit associated value _{Q1 (n, T f),} Q2 (n, T f) , the reference time T0 first data P _n (T0 _n) a half cycle before the reference time T0 _n It is calculated based on the second data P (T0 _n −0.5T _f ) of. Here, the relationship between the first data P (T0 _n ) and the second data P (T0 _n −0.5 T _f ) will be described.

As shown in FIG. 8, in a sine wave having a specific frequency, the amplitude in the phase (π / 4) shows the maximum value, and the amplitude in the phase (3π / 4) shows the minimum value. Therefore, the difference between the amplitude in the phase (π / 4) and the amplitude in the phase (3π / 4) is maximized. Further, the absolute value of the amplitude in the phase (π / 4) and the absolute value of the amplitude in the phase (3π / 4) show the maximum value. The phase (π / 4) and the phase (3π / 4) are out of phase by half a period (π / 2).

Therefore, at the frequency f1 corresponding to the specific frequency of the sine wave, the first data P (T0 _n ) and the second data P (T0 _n −0.5 T _f ) shifted by half a period (π / 2) are used. , One of the unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) is a large value. On the other hand, at the frequency f2 that does not match the specific frequency of the sine wave, when the first data P (T0 _n ) and the second data P (T0 _n −0.5 T _f ) shifted by half a period (π / 2) are used. In addition, one of the unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) is smaller than the above case.

However, even if the phases are deviated by half a period (π / 2), the amplitudes at 0 ° and π / 2 are zero, so the difference between the two and the absolute value of the two are minimized. Therefore, the total related value R1 (T _f ) based on a plurality of unit related values Q1 (n, T _f ) and Q2 (n, T _f ) in which the reference time T0 _n is set to a predetermined time (for example, one cycle). , R2 (T _f ) are calculated. The total related values R1 (T _f ) and R2 (T _f ) have the same relationship with respect to the frequencies f1 and f2 as well as the unit related values Q1 (n, T _f ) and Q2 (n, T _f ). .. That is, at the frequency f1 corresponding to the specific frequency of the sine wave, the total related values R1 (T _f ) and R2 (T _f ) are large values. On the other hand, at the frequency f2 that does not match the specific frequency of the sine wave, the total related values R1 (T _f ) and R2 (T _f ) are small values. Therefore, the frequency specifying units 623 and 633 can specify the vibration frequency based on the total related values R1 (T _f ) and R2 (T _f ).

That is, the vibration frequency is specified by using the relationship between the first data P (T0 _n ) and the second data P (T0 _n −0.5 T _f ) which are deviated from each other by half a cycle. Therefore, the operations of the unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) and the operations of the total related values R1 (T _f ) and R2 (T _f ) are Fourier transform processing and autocorrelation function operations. Compared to the process, the process is very simple. Therefore, the vibration frequency can be measured without using a high-speed arithmetic processing unit.

Further, as described above, the measuring device 60 is high by utilizing the relationship between the first data P (T0 _n ) and the second data P (T0 _n −0.5 T _f ) which are deviated from each other by half a cycle. The vibration frequency can be specified accurately. However, in order for the first data P (T0 _n ) and the second data P (T0 _n −0.5 T _f ) at the frequency f1 that does not match the specific frequency to have the above relationship, a signal from which noise has been removed to some extent is required. Need to use. Therefore, the unit-related value calculation unit 621, 631 does not use the detection signal itself of the vibration sensor (10a), but uses the processing signal processed by the filter processing unit 61. In this way, the measuring device 60 can reliably identify the vibration frequency by filtering the detection signal.

Further, in the first embodiment, the unit-related value calculation unit 621, 631 has, for example, as shown in the equation (8), the first data P (T0 _n ) and the second data P (T0 _n −0.5T). _The unit-related value Q1 (n, T _f ) is calculated based on the difference value from _f ). Alternatively, the unit-related value calculation unit 621, 631 describes the unit based on the difference value between the correlation value of the first data P (T0 _n ) and the correlation value of the second data P (T0 _n −0.5 T _f ). The related value Q1 (n, T _f ) may be calculated. That is, by using the unit-related value Q1 (n, T _f ) obtained from the difference value, it is clear that the total related value R1 (T _f ) has the relationship of the equation (7). As a result, the measuring device 60 can reliably specify the vibration frequency.

Further, in the first embodiment, as shown in the equation (8), the unit-related value calculation unit 621, 631 has the second data P (T0 _n −0.5 T) with respect to the first data P (T0 _n ). _f) subtracting the reference time T0 _n one cycle before the third data P _(T0 n -T _f) adding from reference time T0 _n from 1.5 cycle before the fourth data P _(T0 n -1 .5T _f) based on subtracting the, calculates the unit associated value Q1 (n, _{T f).} As a result, the unit-related value Q1 (n, T _f ) becomes a value in consideration of information for a plurality of cycles, and the vibration frequency can be specified with higher accuracy.

Further, the unit-related value calculation unit 621, 631 subtracts the correlation value of the second data P (T0 _n −0.5T _f ) from the correlation value of the first data P (T0 _n ), and subtracts the correlation value of the second data P (T0 _n −0.5T _f ) from the reference time T0. a correlation value of 1 cycle before the third data P _(T0 n -T _f) adding from _n, the correlation of the fourth data _P of 1.5 cycle before the reference time T0 _n (T0 _n -1.5T _f) The unit-related value Q1 (n, T _f ) may be calculated based on the value subtracted. In this case as well, the same effect is obtained.

Further, in the second embodiment, the unit-related value calculation unit 621, 631 has the absolute value of the first data P (T0 _n ) and the second data P (T0 _n −0.5 T) as shown in the equation (18). _The unit-related value Q1 (n, T _f ) is calculated based on the value added to the absolute value of _f ). Alternatively, the unit-related value calculation unit 621, 631 is an addition value of the correlation value of the absolute value of the first data P (T0 _n ) and the correlation value of the absolute value of the second data P (T0 _n −0.5T _f ). The unit-related value Q1 (n, T _f ) may be calculated based on. That is, by using the unit-related value Q2 (n, T _f ) obtained from the difference value, it is clear that the total related value R2 (T _f ) has the relationship of the equation (17). As a result, the measuring device 60 can reliably specify the vibration frequency.

Further, in the first frequency measurement process (FIGS. 11 and 12) or the second frequency measurement process (FIGS. 13 and 14), the frequency identification units 623 and 633 have a total related value for a part of a predetermined number of target frequencies f. After comparing R1 (T _f ) and R2 (T _f ), compare the total related values R1 (T _f ) and R2 (T _f ) for a predetermined number of different target frequencies f at least once. By doing so, the vibration frequency is specified. As a result, the amount of calculation per operation can be significantly reduced.

Further, in the first frequency measurement process (FIGS. 11 and 12) or the second frequency measurement process (FIGS. 13 and 14), the frequency identification units 623 and 633 refer to a predetermined number (for example, three) of continuous target frequencies f. By comparing R1 (T _f ) and R2 (T _f ) of the total related values of, the tendency of the vibration frequency is acquired, and a predetermined number of continuous target frequencies are sequentially changed based on the tendency, and the obtained total related value is obtained. The vibration frequency is specified by comparing R1 (T _f ) and R2 (T _f ). As a result, the vibration frequency is reached early.

Further, in the first frequency measurement process (FIGS. 11 and 12) or the second frequency measurement process (FIGS. 13 and 14), the frequency specifying units 623 and 633 have a predetermined number including a preset start frequency. First, the comprehensive related values R1 (T _f ) and R2 (T _f ) for the target frequency f are compared. In particular, the starting frequency is the highest frequency or the lowest frequency among the target frequencies f. This facilitates processing until the vibration frequency is reached. The starting frequency is not limited to the highest frequency or the lowest frequency among the target frequencies f, but is the median value of the target frequency f, the upper limit value, the lower limit value, or the lower limit value of the general normal range of heartbeat and respiration. Any frequency can be set from the range of the target frequency f, such as the median value.

Further, in the third frequency measurement process (FIGS. 15 and 16) or the second frequency measurement process (FIGS. 17 and 18), the frequency identification units 623 and 633 have a total related value R1 (T _f ) for all the target frequencies _f. ), R2 (T _f ) may be compared to specify the vibration frequency. As a result, the vibration frequency can be acquired at an early stage. Even in this case, it is a very simple process as compared with the Fourier transform process and the operation process of the autocorrelation function.

Further, in the first frequency measurement process (FIGS. 11 and 12), the second frequency measurement process (FIGS. 13 and 14) or the third frequency measurement process (FIGS. 15 and 16), the unit-related value calculation unit 621 and 631 and the total The related value calculation unit 622,632 has a unit related value Q1 (n, T) for the frequency before and after the specified vibration frequency fmax and the vibration frequency fmax after the vibration frequency fmax is once specified by the frequency specifying unit 623 and 633. _{The operations of f} ), Q2 (n, T _f ) and the total related values R1 (T _f ) and R2 (T _f ) are repeated. Then, the frequency specifying units 623 and 633 repeatedly specify the latest vibration frequency fmax based on the latest calculated total related values R1 (T _f ) and R2 (T _f ).

As a result, the latest vibration frequency fmax can be specified even when the vibration frequency fmax changes. Further, it is possible to obtain the transition of the change of the vibration frequency fmax. This makes it possible to grasp how the vibration frequency fmax is changing.

Further, in the fourth frequency measurement process (FIGS. 17 and 18), the frequency specifying units 623 and 633 are comprehensively related to a predetermined number of target frequencies including the specified vibration frequency after the vibration frequency is once specified. The tendency of change is determined based on the values R1 (T _f ) and R2 (T _f ). Then, the unit-related value calculation unit 621, 631 and the total-related value calculation unit 622, 632 have unit-related values Q1 (n, T _f ), Q2 (n, T _f ), Q2 ( n, T _f ) and the total related values R1 (T _f ) and R2 (T _f ) are calculated, and the frequency specifying unit 623 and 633 calculate the latest calculated total related values R1 (T _f ) and R2 (T _f ). ), The latest vibration frequency is repeatedly specified.

As a result, it is possible to follow the change in the vibration frequency with a predetermined number of target frequencies to be calculated. Therefore, even when the vibration frequency changes quickly, the vibration frequency after the change can be specified at an early stage.

Further, in the first frequency measurement process to the fourth frequency measurement process, the comprehensive related value calculation unit 622, 632 has a plurality of unit related values Q1 (n, T _f ), Q2 (with reference time T0 _n as a predetermined time). When acquiring n, T _f ), a plurality of unit-related values Q1 (n, T _f ) and Q2 (n,) are set to the same frequency (250 Hz, 4 ms in one cycle) regardless of the target frequency f. The calculation of T _f ) is performed. This simplifies the calculation.

On the other hand, the total related value calculation unit 622,632 has a target frequency when acquiring a plurality of unit related values Q1 (n, T _f ) and Q2 (n, T _f ) with the reference time T0 _n as a predetermined time. A plurality of unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) may be calculated by setting the calculation frequency to a different frequency according to f. In this case, since the number of data can be set according to the target frequency, it is possible to suppress variations in the accuracy of the unit-related values Q1 (n, T _f ) and Q2 (n, T _f ) for each target frequency.

Further, in the first embodiment and the second embodiment, the vibration sensor (10a) is a pressure sensor cell 10a arranged on the surface of the body and formed in a planar shape, and the measuring device 60 is a detection signal by the pressure sensor cell 10a. Based on the above, the heartbeat or respiration as biological information of the body facing the pressure sensor cell 10a is measured. That is, by using the pressure sensor cell 10a and performing the above processing, it is possible to reliably measure the heartbeat or respiration, which is a very minute vibration.

1: Biological information measurement system, 10: Sensor unit, 10a: Pressure sensor cell (vibration sensor), 11: First electrode, 12: Second electrode, 13: Dielectric layer, 20: Power supply device, 40: Switch circuit, 50: Switching control device, 60: Vibration frequency measurement device, 61: Filter processing unit, 62: Respiration rate measurement unit, 63: Heart rate measurement unit, 621, 631: Unit-related value calculation unit, 622,632: Comprehensive related value calculation unit , 623, 633: Frequency identification part, Q1 (n, T _f ), Q2 (n, T _f ): Unit related value, R1 (T _f ), R1 (T _f ): Total related value, T0 _n : Reference time

Claims (12)

A vibration frequency measuring device that measures the frequency of vibration included in the detection signal of a vibration sensor.
A filter processing unit that generates a processing signal that extracts a predetermined frequency range from the detection signal, and
For each target frequency of the multiple, the absolute value of the difference between the first output value of the processed signal at the reference time from the reference time and the second output value of the processed signal prior half cycle, or, the first output A unit-related value calculation unit that calculates the absolute value of the difference between the value correlation value and the correlation value of the second output value as a unit-related value,
A total related value calculation unit that calculates a value obtained by adding a plurality of the unit related values having the reference time as a predetermined time for each of the plurality of target frequencies as a total related value.
A frequency specifying unit that compares a plurality of the total related values and specifies the target frequency for the total related value that is the maximum value as the vibration frequency of the detected signal.
A vibration frequency measuring device. A vibration frequency measuring device that measures the frequency of vibration included in the detection signal of a vibration sensor.
A filter processing unit that generates a processing signal that extracts a predetermined frequency range from the detection signal, and
For each of the multiple target frequencies
To the first output value of the processed signal at the reference time, at least, the second output value of the processed signal before half period from the reference time by subtracting, the processed signals in one cycle before the said reference time first The three output values are added, the fourth output value of the processed signal 1.5 cycles before is subtracted from the reference time, and the absolute value of the obtained value is calculated as a unit-related value.
Or, with respect to the correlation value of the first output value, at least, by subtracting the correlation value of the second output value, by adding the correlation value of the third output value, subtracting the correlation value of the fourth output value Then, the unit-related value calculation unit that calculates the absolute value of the obtained value as the unit-related value,
A total related value calculation unit that calculates a value obtained by adding a plurality of the unit related values having the reference time as a predetermined time for each of the plurality of target frequencies as a total related value.
A frequency specifying unit that compares a plurality of the total related values and specifies the target frequency for the total related value, which is the maximum value, as the vibration frequency of the detected signal.
A vibration frequency measuring device. A vibration frequency measuring device that measures the frequency of vibration included in the detection signal of a vibration sensor.
A filter processing unit that generates a processing signal that extracts a predetermined frequency range from the detection signal, and
For each target frequency of the multiple, the value obtained by adding the absolute value of the second output value of the processed signal prior half cycle from the absolute value and the reference time of the first output value of the processed signal at least a reference time, Alternatively, a unit-related value calculation unit that calculates at least a value obtained by adding the correlation value of the absolute value of the first output value and the correlation value of the absolute value of the second output value as a unit-related value.
A total related value calculation unit that calculates a value obtained by adding a plurality of the unit related values having the reference time as a predetermined time for each of the plurality of target frequencies as a total related value.
A frequency specifying unit that compares a plurality of the total related values and specifies the target frequency for the total related value that is the maximum value as the vibration frequency of the detected signal.
A vibration frequency measuring device. The frequency specifying unit compares the total related values for a certain predetermined number of target frequencies, and then compares the total related values for a different predetermined number of target frequencies at least once. The vibration frequency measuring device according to any one of claims 1 to 3 , which specifies the vibration frequency. The frequency specifying unit acquires the tendency of the vibration frequency by comparing the comprehensive related values for a predetermined number of continuous target frequencies, and sequentially changes the continuous predetermined number of target frequencies based on the tendency. The vibration frequency measuring device according to claim 4 , wherein the vibration frequency is specified by comparing the obtained comprehensive related values. The vibration frequency measuring device according to claim 4 or 5 , wherein the frequency specifying unit first compares the total related values with respect to a predetermined number of target frequencies including a preset start frequency. The vibration frequency measuring device according to claim 6 , wherein the starting frequency is the highest frequency or the lowest frequency among the target frequencies. The vibration frequency measuring device according to any one of claims 1 to 3 , wherein the frequency specifying unit specifies the vibration frequency by comparing the comprehensive related values for all the target frequencies. After the vibration frequency is once specified by the frequency specifying unit, the unit-related value calculation unit and the comprehensive-related value calculation unit have the unit-related value for the specified vibration frequency and frequencies before and after the vibration frequency. And the calculation of the total related value is repeated,
The vibration frequency measuring device according to any one of claims 1 to 8 , wherein the frequency specifying unit repeatedly specifies the latest vibration frequency based on the latest calculated total related value. After the vibration frequency is once specified, the frequency specifying unit determines a tendency to change based on the total related value for a predetermined number of target frequencies including the specified vibration frequency.
The unit-related value calculation unit and the total-related value calculation unit calculate the unit-related value and the total-related value for a predetermined number of consecutive target frequencies based on the determined tendency.
The vibration frequency measuring device according to any one of claims 1 to 8 , wherein the frequency specifying unit repeatedly specifies the latest vibration frequency based on the latest calculated total related value. When acquiring the plurality of unit-related values having the reference time as a predetermined time, the comprehensive related value calculation unit calculates the plurality of unit-related values by setting the calculation frequency to a different frequency according to the target frequency. The vibration frequency measuring device according to any one of claims 1 to 10 . The vibration sensor is a pressure sensor cell arranged on the surface of the body and formed in a planar shape.
The vibration according to any one of claims 1 to 11 , wherein the vibration frequency measuring device measures heartbeat or respiration as biological information of the body facing the pressure sensor cell based on a detection signal by the pressure sensor cell. Frequency measuring device.

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