JPH10234684A - Measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly complete the gain setting of detection signals before the instruction of timing start and to reduce the setting change of a gain after the instruction of the timing start. SOLUTION: A pulse wave detection part 110 outputs pulse wave signals so as to detect a pulse rate, an amplifier circuit 313 amplifies the pulse wave signals and an A/D conversion circuit 315 converts the amplified pulse wave signals to digital signals. An FFT arithmetic circuit 317 FFT-processes the converted pulse wave signals and a CPU 301 obtains the pulse rate from an FFT processing result. In this case, the CPU 301 sets the gain of the amplifier circuit 313 at every 4 seconds based on the converted pulse wave signals before the instruction of the timing start by an input part 205 and sets it at every 20 seconds after the instruction of the timing start.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus for amplifying a detection signal such as a pulse wave signal or a body motion signal and then processing the amplified signal to obtain a pulse rate, a body motion pitch and the like.

[0002]

2. Description of the Related Art Conventionally, in a measuring device for measuring a pulse rate, a body movement pitch, and the like, signals such as a pulse wave signal indicating a subject's pulse wave waveform and a body movement signal indicating a body movement pitch are obtained.
After being detected by a sensor and amplified by a predetermined gain,
The arithmetic processing such as the FT processing is executed, the frequency component is analyzed, and information such as a pulse rate and a body movement pitch is measured. These pieces of information have a significant meaning when associated with the elapsed time from the start of timekeeping. For example, by relating the pulse rate, the body movement pitch, and the like to the elapsed time from the start of the running, the exercise intensity and the pace in the running can be determined. For this reason, the measurement result is stored in association with the elapsed time from the timing start instruction. This makes it possible to perform various processes based on the stored measurement results, for example, a process of displaying a temporal transition of the measurement results during or after the measurement, and is expected to be utilized in training and the like. .

[0003] The level of a signal detected by a sensor is
Since it fluctuates due to the surrounding environment, the sensor mounting state, and the like, it does not become constant but changes every measurement. This means
This causes an error in the arithmetic processing. Therefore, this type of measuring device has a configuration in which the gain is reset so that the level of the detection signal falls within a level range sufficient for arithmetic processing, that is, a configuration in which the gain is automatically controlled. . Further, before the instruction to start timing is issued, the current measurement result is displayed, and the user is made to confirm whether the measurement is being performed correctly.

[0004]

The above-mentioned automatic gain control is usually performed at regular intervals, so that it is performed at the same cycle before and after the start of timing. Here, if the setting cycle of the gain is lengthened, it takes time to set an appropriate gain before the start of timing, so that there is a problem that the measurement with the elapsed time cannot be started immediately. On the other hand, if the gain setting cycle is shortened,
After the timing starts, the gain changes frequently,
There has been a problem that errors in the arithmetic processing are likely to occur. The present invention has been made in view of the above-described problem, and its purpose is to quickly complete the gain setting of the detection signal before instructing the start of timekeeping, and to set the gain after instructing the start of timekeeping. Another object of the present invention is to provide a measuring device capable of reducing the change in gain setting.

[0005]

In order to achieve the above object, a first aspect of the present invention comprises a detecting means for detecting a displacement of an object to be measured as a signal, and an amplifying means for amplifying a signal detected by the detecting means. In a measuring device that performs arithmetic processing on the signal amplified by the amplifying means to obtain a desired measurement result, instructing means for instructing start of timekeeping, and after the instruction is issued by the instructing means, the instruction is issued. First cycle designating means for designating a cycle longer than before performing;
For the signal amplified by the amplifying means, the first
And a gain setting means for setting a gain for the amplifying means based on the monitoring result.

In order to achieve the same object, a second invention comprises a detecting means for detecting a displacement of an object to be measured as a signal,
Amplifying means for amplifying the signal detected by the detecting means, and in a measuring apparatus for processing the signal amplified by the amplifying means to obtain a desired measurement result, the signal amplified by the amplifying means Sampling means for sampling, instructing means for instructing the start of timekeeping, and a first number-of-samples designation for designating a larger number of samples after the instruction is given by the instructing means than before the instruction is given Means,
For the signal amplified by the amplifying means, the first
Monitor only the number of samples specified by the sample number specifying means of
Gain setting means for setting a gain for the amplifying means based on the monitoring result.

(Operation) According to the first invention, the first cycle designating means designates a longer cycle after the instruction to start timekeeping than the time before the instruction to start timekeeping to the gain setting means. The gain setting means monitors the amplified signal of the detection signal for a designated period, and sets the gain of the detection signal based on the monitoring result. For this reason, the gain setting is frequently performed before the instruction to start the timekeeping, but not so frequently after the instruction to start the timekeeping. Further, according to the second invention, the first sample number designating means designates, to the gain setting means, a larger number of samples after the instruction to start timing than before the instruction to start timing. The gain setting means monitors the sample of the amplified signal of the detection signal by the designated number of samples,
The gain of the detection signal is set based on the monitoring result. Therefore, as in the first aspect, the gain setting is frequently performed before the instruction to start the timekeeping, but not so frequently after the instruction to start the timekeeping. here,
In some cases, it is desirable to make the cycle or the number of samples for determining the setting of the gain different depending on the presence or absence of the body movement of the subject, not before and after the instruction to start timing. The gain should be set in consideration of the maximum value. However, since the maximum value may have been affected by sudden noise, it is desirable to exclude the maximum value from the determination.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

<1: First Embodiment> First, a first embodiment of the present invention will be described. The measuring device according to the present embodiment sets the determination period for setting the gain to be longer after the instruction than before the instruction to start timing (start).

<1-1: External Configuration> First, the external configuration of the present embodiment will be described. As shown in FIG. 1A, the measuring device according to the present embodiment has, as shown in FIG. 1A, a device body 100 having a wristwatch structure, a cable 101 connected to the device body, and a distal end side of the cable. It comprises a pulse wave detector 110 provided. The wristband 102 is attached to the apparatus main body 100, one end of which is wound around the left arm of the user from the 12:00 direction of the apparatus main body 100, and the other end is fixed at the 6 o'clock direction of the apparatus main body 100. A connector 103 is provided on the front side of the apparatus main body 100 in the 6 o'clock direction. This connector section 103 includes a cable 101
Is detachably attached to the connector piece 104 provided at the end of the connector piece.

On the other hand, on the surface of the
(A liquid crystal display panel) is provided,
The button switches 131, 1
32 are provided. Button switches 133 to 137 are provided on the outer periphery of the apparatus main body 100.
, 5 o'clock, 7 o'clock, 9 o'clock and 11 o'clock respectively. Of these, button switch 1
Reference numeral 34 is used for selecting a function, and button switches 131 and 132 are used for giving various instructions. For example, the selection of the function of measuring the biological information with the elapsed time is performed by operating the button switch 134, the instruction to start the time measurement is performed by turning on the button switch 131, and the instruction to end the time measurement is performed during the time measurement. Then, the operation is performed by turning on the button switch 131 again. Also, the lap instruction is given by the button switch 1
32. The details will be described later.

On the other hand, as shown in FIG. 1B, the pulse wave detecting section 110 is a sensor section 1 comprising a blue LED and a light receiving section.
11 and is shielded from light by the sensor fixing band 112 and is worn between the base of the index finger of the user's left hand and the second finger joint. Then, the sensor unit 111 emits light from the blue LED, and of the light, the light reflected by the hemoglobin in the capillary blood vessel is received by the light receiving unit, and the output signal from the received light is used as a pulse wave signal, and the cable 101 Is output to the apparatus main body 100 via the.

<1-2: Functional Configuration> Next, the functional configuration of the present embodiment will be described. FIG. 2 is a block diagram illustrating a functional configuration of the measurement device according to the present embodiment. In this figure, a biological information detecting unit 201 includes a pulse wave detecting unit 110 shown in FIG. 1 and a body motion detecting unit (not shown here) including an acceleration sensor, and a pulse wave of a subject wearing this apparatus. And a body motion signal indicating a body motion state are output as analog signals. Amplifying unit 20
2 represents each analog signal by the biological information detection unit 201,
Each is amplified with a predetermined gain. Biological information conversion unit 20
Reference numeral 3 denotes a unit for converting each analog signal amplified by the amplifier 202 into a digital signal. The biological information calculation unit 204 performs arithmetic processing on these digital signals, and based on the result, a pulse rate, a body movement pitch, and the like. Is output as biological information. Therefore, although not shown in FIG. 2, the biological information
Up to 04, there are systems for processing pulse wave signals and systems for processing body motion signals.

On the other hand, the input unit 205 detects the operation state of the button switches 131 to 137 in FIG.
This is for notifying the switching of the mode and various instructions.
The mode control unit 206 controls each unit according to the notification from the input unit 205. The gain setting unit 207 monitors the digital signal (sampling data) converted by the biological information conversion unit 203 and performs an operation of setting a gain in the amplifier 202 at different periods before and after the start of time measurement. Here, the gain setting unit 207 sets the gain for each system, and sets the gain setting determination cycle to, for example, 4 seconds before the instruction to start the timekeeping, and sets the determination cycle after the instruction to start the timekeeping. For example, the gain is set to 20 seconds at a longer cycle than before the instruction to start timing.

The biological information storage unit 208 stores the pulse rate and body movement pitch, which are the biological information obtained by the biological information calculation unit 204, in a time-series manner. Display unit 120
Are the same as those in FIG. 1 and mainly display the following. That is, the display unit 120 performs display of the pulse wave number or the body movement pitch obtained at the present time and display according to the storage content of the biological information storage unit 208. At this time, whether to display either the pulse rate or the body movement pitch is selected in advance by operating the button switch 136, but originally, both may be displayed at the same time.

<1-3: Electrical Configuration> Next, a configuration for actually implementing the above-described functional configuration will be described.
FIG. 3 is a block diagram illustrating an electrical configuration of the measurement device according to the present embodiment. In this figure, a CPU 301
Performs control of each unit and data transfer according to a control program stored in the ROM 302.
Mode control section 206 and gain setting section 2 in FIG.
07. The RAM 303 stores biological information,
Various data generated during the execution of the control program by the CPU 301 is temporarily stored, and corresponds to the biological information storage unit 208 in FIG. Oscillation circuit 304
Supplies a clock signal serving as a basis for control to the CPU 301, and the timer circuit 305 measures time under the control of the CPU 301.

On the other hand, the amplification circuit 313
The amplifying circuit 314 amplifies the pulse wave signal by the zero sensor unit 111, and the amplifying circuit 314 amplifies the body motion signal by the body motion detecting unit 312 including the acceleration sensor. That is, the pulse wave detecting unit 110 and the body motion detecting unit 312 correspond to the biological information detecting unit 201 in FIG.
And 314 correspond to the amplifier 202. here,
The gains of the amplifier circuits 313 and 314 are set according to an instruction from the CPU 301. Note that the body motion detection unit 312 is
What is not shown in FIG. 2 and FIG.
This is because it is built in 0.

The A / D conversion circuits 315 and 316 convert the amplified pulse wave signal and body movement signal into digital signals, respectively.
03. Here, the A / D conversion circuits 315 and 31
6 is 8H in the present embodiment.
z, which is a sufficiently high frequency for the pulse wave waveform and the body motion signal. Therefore, the sampling data of the pulse wave signal and the body motion signal are obtained in 32 points in 4 seconds,
In 20 seconds, 160 points will be obtained. A /
The quantization of the D conversion circuits 315 and 316 is performed by 8 bits in this embodiment. Also, the sampling data from the A / D conversion circuits 315 and 316 are supplied to the CPU 301, respectively, and are amplified by the amplification circuits 313 and 31.
4 for determining the gain setting.

The FFT operation circuit 317 performs FFT (Fast Fourier Transform) processing on the sampled pulse wave signal every 4 seconds, analyzes the frequency, and, for example, of the pulse wave spectrum obtained as the analysis result, The frequency component is extracted as a pulse component indicating a pulse, and the pulse rate is obtained by converting the frequency indicating the pulse component into one minute. On the other hand, the FFT operation circuit 31
Reference numeral 8 denotes an FFT processing of the sampled body motion signal every 4 seconds, frequency analysis, and, for example, extracts a frequency component having a maximum level as a basic component of the body motion from a body motion spectrum as a result of the analysis. In addition, the body motion pitch is obtained by converting the frequency indicating the basic component into one minute. That is, the FFT operation circuits 317 and 318 correspond to the biological information operation unit 204 in FIG.

<1-3-1: Detailed Configuration of Amplification Circuit> Next, the configuration of the amplification circuits 313 and 314 will be described with reference to FIG. Since the configurations of the two are the same, the description will be made by taking the amplifier circuit 313 as an example. As shown in the figure, the amplification circuit 313 amplifies the pulse wave signal output by the phototransistor in the pulse wave detection unit 110 with a constant gain, and removes a frequency component below a predetermined frequency. Low-pass filter 4
20 and a cascade connection of a variable gain amplifying unit 430 that sets a gain in accordance with an instruction from the CPU 301 (see FIG. 3). The variable gain amplifying section 430 includes data lines d1 to d4 supplied from the CPU 301.
Has analog switches 431 to 434 which are turned on / off in accordance with the signal levels of the signals. Here, the analog switches 431 to 434 are turned on when the signal level of the corresponding data line becomes the “H” level, and the CPU 301 sets one of the data lines d1 to d4 for one. Only the signal level is set to “H” level. Therefore, the analog switches 431 to 434 are
Only one of them is turned on.

Here, the resistance values of the feedback resistors R1 to R5 are, for example, R1 = 40 kΩ, R2 = 40 kΩ, R
Assuming that 3 = 80 kΩ, R4 = 160 kΩ, and R5 = 320 kΩ, the gain of the variable gain amplifying section 430 becomes “H” level on the data line d 1 and the analog switch 4
When the switch 31 is turned on, the value is doubled, and the data line d2 becomes “H”.
When the analog switch 432 is turned on, the signal becomes quadruple, and the data line d3 becomes “H” level.
When the analog switch 433 is turned on, it becomes 8 times,
In addition, when the data line d4 goes to the “H” level and the analog switch 434 is turned on, the value becomes 16 times. Since each operational amplifier operates on a single power supply, the input signal is pulled up to a voltage V _DD / 2 which is half of the power supply voltage V _DD .

<2: Operation> Next, the operation of the measuring apparatus according to the present embodiment will be described. As described above, since the apparatus main body has a wristwatch-type structure, it is possible to execute various functions such as display of the current time, but the biological information, that is, the pulse rate and body movement pitch are measured. Since the functions other than the function of displaying the information are not directly related to the present invention, the description thereof is omitted.

<2-1: Until Instruction to Start Timekeeping> When the user operates the button switch 134 in FIG. 1 to instruct the measuring device to execute the function of measuring the biological information along with the elapsed time, FIG. Then, the input unit 205 that has input the operation notifies the CPU 301 of the fact. Upon receiving this notification, the CPU 301 clears the area for storing the biological information in the RAM 303 and then performs the processing of setting the gain in the amplifier circuits 313 and 314 until there is an instruction to start timekeeping. The operation is performed every 4 seconds in accordance with the above operation.

First, the gain setting operation performed before the instruction to start the time measurement will be described by taking a pulse wave signal system as an example. First, the CPU 301 inputs the sampling data of the pulse wave signal by the A / D conversion circuit 315 for 4 seconds, that is, 32 points, and inputs 2 bits of the 8-bit data as shown in FIG. 4 bits of up to 5 SB are selected and stored in the RAM 303. Second, the CPU 301 compares the values of the stored 32-bit 4-bit data with each other and extracts the one having the second largest value. Third, the CPU 301 is configured as shown in FIG.
Referring to the table shown in (b), the rank of the gain corresponding to the value of the extracted 4-bit data is determined. For example, the CPU 301 determines that the extracted 4-bit data is “00”.
If it is "10"("2" in decimal notation), the gain is 1
Judge that you should rank up. Fourth, the CPU 301
Sets the signal levels of the data lines d1 to d4 in consideration of both the currently set gain and the determined gain rank. For example, CP
When the signal level of only the data line d2 is set to the “H” level at the present time, when determining that the gain should be increased by one rank, the U301 sets the signal level of only the data line d3 to the “H” level. As a result, the newly set gain is twice the gain at the present time.

The above-described first to fourth operations are performed by the CPU 301.
Is repeated every four seconds before the instruction to start timing is performed, as shown in FIG. Also, the CPU 301
Performs the same gain setting for the body motion signal system. In this manner, the user operates the button switch 134
Is operated to instruct the measuring device to execute the function of measuring the biological information together with the elapsed time.
Since the gain of 3, 314 is reset every 4 seconds,
Immediately after the pulse wave detector is mounted, it is possible to quickly set an appropriate gain for the pulse wave signal. In addition, when the temperature is low, the capillaries contract, so that it is difficult to obtain the reflected light by the hemoglobin, and the level of the pulse wave signal is also reduced. Before the start instruction, an appropriate gain can be quickly set for the pulse wave signal.

In this embodiment, the reason why the 8-bit sampling data selected by the A / D conversion circuits 315 and 316 is selected as 4 bits and processed is that the processing capacity of the CPU 301 is 4 bits. Therefore, if a CPU having a high processing capability is adopted for the CPU 301, a configuration may be adopted in which all 8 bits are input and processed. Further, in the present embodiment, the reason why the value whose value is the second largest among the 32 points is extracted is as follows. That is, the gain should originally be set based on the maximum value, but the maximum value is excluded because it may have been affected by sudden noise.

When setting the gain, the CPU 301 converts the pulse wave signal sampled by the A / D conversion circuit 315 in order to confirm to the user that the pulse wave detector 110 is correctly worn on the finger. The FFT operation circuit 317 causes the display unit 120 to display the pulse rate at that time. Here, since the FFT operation circuit 317 performs the processing every four seconds, the display of the pulse rate is also updated every four seconds.

<2-2: From After Instruction to Start Timekeeping to Instruction to End Timekeeping> After that, when the user operates the button switch 131 to instruct the start of timekeeping of biological information corresponding to the elapsed time, the CPU 301 The measurement of biological information corresponding to the elapsed time is started, and the amplification circuits 313 and 314 are started.
Is performed every 20 seconds.

First, the gain setting operation performed after the instruction to start the time measurement will be described by taking a pulse wave signal system as an example. First, the CPU 301 inputs the sampling data of the pulse wave signal by the A / D conversion circuit 315 for 4 seconds, that is, 32 points, and inputs 2 bits of the 8-bit data as shown in FIG. 4 bits of up to 5 SB are selected and stored in the RAM 303. Second, the CPU 301 compares the values of the stored 32-bit 4-bit data with each other, extracts the value having the second largest value, and stores the extracted value in the RAM 303. This first
And the second operation is repeated for 20 seconds, that is, five times. Therefore, five 4-bit data having the second largest value are stored in the RAM corresponding to five periods that are separated by 20 seconds.
303.

When five pieces of 4-bit data are stored in the RAM 303, thirdly, the CPU 301 compares the values of the stored five pieces of 4-bit data with each other, sorts the magnitudes of the values in order, and sorts the values. The average value is determined for three of the samples. That is, two large values are excluded from the calculation of the average value. Fourth, the CPU 301
The rank of the gain corresponding to the obtained average value is determined with reference to the table shown in FIG. For example, the CPU 301
Determines that the gain should be reduced by one rank if the calculated average value is "13". Fifth, the CPU 301
The signal levels of the data lines d1 to d4 are determined and the gain is set in consideration of both the currently set gain and the determined gain rank. For example, the CPU 30
When the signal level of only the data line d2 is set to the "H" level at the present time and the gain is determined to be lowered by one rank, the signal level of the data line d1 alone is set to the "H" level. As a result, the newly set gain is 倍 of the gain at the present time. The CPU 301 repeats the above-described first to fifth operations every 20 seconds after the instruction to start the time measurement, as shown in FIG. 6B. The CPU 301 also performs such a gain setting for the body motion signal system in the same manner.

As described above, the user operates the button switch 13
When the user operates 1 to instruct the start of timing of the biological information corresponding to the elapsed time, the gain of the amplification circuits 313 and 314 becomes 2
It is reset every 0 seconds. For this reason, since the gain is not changed so frequently, an error hardly occurs in the FFT calculation processing. In the present embodiment, the reason why two data having a large value are excluded in the calculation of the average value is as follows. That is, data having a large value is likely to be caused by an arbitrary factor, and also to reduce the computational load on the CPU 301 having a low processing capacity.

The CPU 301 performs such a gain setting and also performs the following measuring operation. That is, when an instruction to start timing is issued, the CPU 301
The timer circuit 305 is caused to measure the elapsed time from the start of the clock, and the result is displayed on the segment display unit 123.
The pulse wave signal and the body motion signal that have passed through the conversion circuits 315 and 316 are respectively processed. And the CPU 301
Represents the obtained biological information such as the pulse rate and the body movement pitch by R
In addition to sequentially storing the information in the AM 303, the selected one of the pulse rate and the body movement pitch is displayed on the segment display unit 122. here,
Since the FFT operation circuits 317 and 318 obtain biological information every four seconds, the biological information is stored in the RAM 303 every four seconds and the display on the segment display unit 122 is updated every four seconds. Become.

When the user operates the button switch 132 to give a lap instruction after the start of the timing, the CPU 301
Performs the following first to sixth controls. That is, the first
In addition, the CPU 301 obtains the elapsed time (split time) when the lap instruction is issued from the time counting circuit 305, and gives this to the segment display for a certain period (for example, only 10 seconds) with priority over the elapsed time at the present time. It is displayed on the unit 123. Secondly, the CPU 301 calculates the difference between the elapsed time in the lap instruction immediately before the lap instruction and the elapsed time in the lap instruction measured by the timing circuit 305 to obtain the lap time of the lap section. Is displayed on the segment display section 124 together with the number of laps. Third, the CPU 301
Reads all the pulse rate and body movement pitch stored in the RAM 303 in the lap section, and obtains, for example, an average value thereof as a processing result. Fourth,
The CPU 301 displays the selected one of the pulse rate and the body movement pitch on the segment display unit 122 for a certain period of time (for example, only 10 seconds) out of the biological information as the processing result at every 4 seconds at the present time. Display priority. Fifth, the CPU 301 causes the RAM 303 to store the biological information as the processing result in association with the lap time and the lap number. Sixth, CPU3
01 reads out all the biological information associated with the lap time and the number of laps from the RAM 303, and selects either the pulse rate or the body motion pitch from the biological information as the processing result with the lap number as the x-axis. One value is set on the y-axis, and the bar graph is displayed on the dot matrix display unit 121. Thereby, how the average value of the biological information in the lap section changes for each lap is displayed. The CPU 301 performs such first to sixth controls each time a lap instruction is issued.

When the user again operates the button switch 131 during the time measurement to instruct the time stop, C
The PU 301 obtains the elapsed time from the start of the timing to the stop of the timing by the timing circuit 305, and displays this in the segment display unit 1.
23 is displayed. In this state, the biological information as the processing result is stored in the RAM 303 in association with the lap time and the lap number, and only for the lap instruction. When the user operates the button switch 131 again after instructing to stop timing, the CPU 301 restarts timing. When resuming, the control unit 201 stores the biological information in the RA
It is stored in M303.

<2-3: After Measurement> As described above, various displays are performed on the display unit 120 during the timing (especially immediately after the lap instruction is performed).
Further, in the present embodiment, the stored biological information can be called even after the measurement. This function will be briefly described below. When the user operates the button switch 134 in FIG. 1 to instruct the measuring device to execute the function of reading the stored biological information, FIG.
, The input unit 205 that has input the operation notifies the CPU 301 of the fact. CPU 30 receiving this notification
1 is to read all the biological information, which is the processing result associated with the lap time and the number of laps, stored in the RAM 303, and select either the pulse rate or the body movement pitch from the biological information with the lap number as the x-axis. One of the obtained values is set on the y-axis, and the bar graph is displayed on the dot matrix display unit 121. Thereby, how the average value of the biological information in the lap section changes for each lap is displayed.

Further, the user operates the button switch 131,
When the user operates 132 to instruct the biometric information to be called in a specific lap section, the CPU 301 reads the biometric information in the lap section together with the lap time, and displays the lap time and the number of laps on the segment display unit 124. One of the selected values of the pulse rate and the body movement pitch according to the biological information is displayed on the segment display unit 122.

As described above, according to the present embodiment, in addition to the fact that biological information can be measured and various displays can be made, the gain setting interval is set to every four seconds before the instruction to start timing is made. Since the setting is performed, the gain setting can be completed quickly, but since the setting is performed every 20 seconds after the instruction to start the time measurement, the influence of the error in the arithmetic processing can be reduced.

In this embodiment, the sampling data by the A / D conversion circuit is used for setting the gain. However, the present invention is not limited to this, and the analog signal before conversion may be used by itself. good. In this case, the gain may be set based on the maximum value held by the peak hold circuit, the signal smoothed by the low-pass filter, or the like.

<3: Second Embodiment> In the above-described first embodiment, the gain setting is determined by changing the cycle before and after the start of time measurement. However, in the second embodiment, the number of samples is determined. Is determined differently. Since the configuration according to the second embodiment is the same as that of the first embodiment shown in FIGS. 1 to 4, description thereof will be omitted, and the following description will focus on differences in operation.

First, before instructing the start of timing, the CPU
Reference numeral 301 denotes a process of setting a gain for the amplifier circuits 313 and 314 in accordance with the operation of the FFT processing operation circuits 317 and 318 each time the sampling data by the A / D conversion circuits 315 and 316 reaches 32 points. Here, the CPU 301 converts the 32 points of sampling data into
Processing is performed in the same manner as in the first embodiment. For this reason, as shown in FIG. 7A, the CPU 301 according to the second embodiment repeatedly sets the gain every 32 points, that is, every 4 seconds before the instruction to start the time measurement. The operation is substantially the same as in the first embodiment.

Next, when the user operates the button switch 131 to instruct the start of measuring the biological information corresponding to the elapsed time, the CPU 301 starts measuring the biological information corresponding to the elapsed time. At this time, the CPU 301 repeatedly performs the following operation every four seconds. That is, first, the CPU
Reference numeral 301 denotes 32 points (ie, for 4 seconds) of sampling data of the pulse wave signal by the A / D conversion circuit 315,
As shown in FIG. 5A, four bits of 2SB to 5SB are selected from these 8-bit data, and
It is stored in the AM 303. Second, the CPU 301 compares the stored values of the 32-point 4-bit data with each other, extracts the one with the second largest value, and stores it in the RAM 303. That is, the sample data having the second value in the period is stored every four seconds. Third, CP
U301 compares the values of the five sample data extracted in the past 20 seconds from the present time with each other, sorts the values in order, and calculates the average value of the three small ones. Therefore, two large values are excluded from the calculation of the average value, but substantially take into account the past 160 sample data. Fourth, the CPU 301, as in the first embodiment,
Referring to the table shown in FIG. 5B, the rank of the gain corresponding to the obtained average value is determined. Fifth, CP
U301 determines the signal level of the data lines d1 to d4 and sets the gain in consideration of both the currently set gain and the determined gain rank, as in the first embodiment.

The above first to fifth operations are performed by the CPU 301
Is repeated every four seconds after the instruction to start timing is issued, as shown in FIG. 7B. Also, the CPU 301
Performs similar gain setting for the body motion signal system. After all, in the second embodiment, the setting of the gain after the instruction to start the timing is performed every 4 seconds, which is the same as before the instruction to start the timing, but the sample data serving as the basis for the determination is not changed before the instruction to start the timing. 32 points (ie 4
Second), but 16 seconds after the instruction to start timing.
0 point (ie, 20 seconds). Further, as shown in FIG. 7B, the sample data serving as the basis for the determination of the gain setting after the instruction to start the clocking is sequentially shifted so as to overlap with the sample data based on the previous time. Therefore, the interval at which the gain is set is the same before and after the instruction to start timing, but it can be said that the frequency at which the gain is actually changed is lower after the instruction than before the instruction to start timing. In other words, after the instruction to start the timing, even if the gain is set, it is likely that the gain is set to keep the current gain. In the second embodiment,
The display and storage processing of the pulse rate and body movement pitch as the biological information are the same as in the first embodiment.

<4: Third Embodiment> In the above-described first and second embodiments, the gain setting conditions are changed before and after the instruction to start timing. However, the present invention is not limited to this. Not limited. For example, if the relationship between the pulse rate and the body movement pitch is regarded as more important, it may be desirable to make the gain setting condition different depending on whether or not the user is exercising, rather than the instruction to start timing. Therefore, in the third embodiment, if the user actually starts exercising, the measurement conditions are changed. Since the configuration according to the third embodiment is the same as that of the first embodiment shown in FIGS. 1 to 4, description thereof will be omitted, and the following description will focus on differences in operation.

First, the CPU 301 executes the FFT operation circuit 3
From the processing result of 18, it is determined whether or not the user has started exercise. More specifically, the CPU 301 determines that the user is in a resting state if the level of any of the frequency components is equal to or less than a certain threshold value in the body motion spectrum as the analysis result, while determining that the user is in the resting state. For example, it is determined that the user is in an exercise state. Here, the CPU 301
When it is determined that the vehicle is in a resting state, the gain is set every four seconds in the same manner as before the instruction to start timing in the first embodiment. In the same manner as after the start instruction, the gain is set every 20 seconds. That is, in the third embodiment, the determination cycle of the gain setting is made different depending on the presence or absence of the body movement, not the instruction of the start of the time measurement.

In the third embodiment, the gain may be set as in the second embodiment. That is, it is conceivable that the gain setting interval is the same depending on the presence or absence of body motion, and that the number of sample data serving as a basis for determining the gain setting when there is body motion is larger than when there is no body motion. Can be

[0046]

As described above, according to the present invention, the following effects can be obtained. Since the gain setting is performed frequently before the instruction to start timing, it is possible to complete the gain setting quickly.On the other hand, after the instruction to start timing, the gain setting is not performed so frequently. It is possible to reduce the cost (claims 1, 3, 5). If the subject is in a resting state, the gain setting can be completed quickly, while if the subject is in an exercising state, the change in the gain can be reduced (claims 2 and 4).
It is possible to set the gain by excluding the maximum value that may have been affected by the sudden noise from the determination target.

[Brief description of the drawings]

FIG. 1A is a diagram illustrating an external configuration of a measurement device according to a first embodiment of the present invention, and FIG. 1B is a diagram illustrating a configuration of a pulse wave detection unit in the measurement device.

FIG. 2 is a block diagram showing a functional configuration in the embodiment.

FIG. 3 is a block diagram showing an electrical configuration in the embodiment.

FIG. 4 is a circuit diagram illustrating a detailed configuration of an amplifier circuit according to the first embodiment.

FIGS. 5A and 5B are diagrams for explaining gain setting in the same embodiment. FIG.

FIG. 6A is a diagram for explaining a gain setting operation before an instruction to start timekeeping in the embodiment; FIG. 6B is a diagram for explaining a gain setting after an instruction to start timekeeping in the embodiment; It is a figure for explaining operation.

FIG. 7 (a) shows a second embodiment of the present invention.
It is a figure for explaining the gain setting operation | movement before the instruction | indication of a timekeeping start, and (b) is a figure for describing the gain setting operation | movement after the instruction | indication of a timekeeping start in the same embodiment.

[Explanation of symbols]

110 pulse wave detecting section, 312 body movement detecting section (all detecting means), 313, 314 amplifying circuits (amplifying means), 315, 316 A / D conversion circuit (sampling means), 205 input part (instruction means), 301 CP
U (first and second cycle specifying means, gain setting means, first and second sample number specifying means)

Claims (6)

[Claims] 1. A detecting means for detecting a displacement of a measurement target as a signal, and an amplifying means for amplifying a signal detected by the detecting means, wherein the signal amplified by the amplifying means is arithmetically processed to obtain a desired signal. In a measuring device for obtaining a measurement result, instructing means for instructing start of timekeeping, and first cycle designating means for designating a longer cycle after the instruction is given by the instructing means than before the instruction is given. The signal amplified by the amplifying means is the first signal
And a gain setting means for monitoring a period designated by the period designation means and setting a gain for the amplification means based on the monitoring result. 2. The measuring device according to claim 1, wherein a body movement detecting means for detecting a body movement of the subject, a determining means for determining the presence or absence of the body movement based on a detection result of the body movement detecting means, and the determining means A second cycle for specifying to the gain setting means a period longer than that for the case where it is determined that there is no body movement, as compared with the case where it is determined that there is no body movement, in place of the first cycle specifying means.
And a cycle designating means. 3. A detecting means for detecting a displacement of a measurement target as a signal, and an amplifying means for amplifying a signal detected by the detecting means, wherein the signal amplified by the amplifying means is arithmetically processed to obtain a desired signal. A measuring device for obtaining a measurement result of: a sampling unit for sampling the signal amplified by the amplifying unit; an instruction unit for instructing start of timing; and an instruction after the instruction by the instruction unit is performed. First sample number designating means for designating a larger number of samples than before the operation is performed; and
Monitor only the number of samples specified by the sample number specifying means of
A measuring apparatus comprising: gain setting means for setting a gain for the amplifying means based on the monitoring result. 4. The measuring device according to claim 3, wherein a body movement detecting means for detecting a body movement of the subject, a determining means for determining the presence or absence of the body movement based on a detection result of the body movement detecting means, and the determining means Is larger than the case where it is determined that there is no body movement, the second sample number designated to the gain setting means in place of the first sample number designating means. A measuring device comprising: a designation unit. 5. The gain setting unit according to claim 3, wherein the sample at the time of setting the gain this time overlaps with a part of the sample at the time of setting the gain last time, and monitors the sample. Measuring device. 6. The measuring apparatus according to claim 1, wherein the gain setting means sets the gain without considering a maximum value in a designated cycle or the number of samples.