JPH0152015B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heart rate monitor that measures a person's pulse.
Especially regarding heart rate monitors mounted on cars. When driving a vehicle, if the driver's health is not good, there is a high possibility of causing an accident.
For example, if you continue to drive for a long time without taking a break, fatigue accumulates, your health condition worsens, and your ability to concentrate decreases. Heart rate is one barometer that can tell us about a person's health condition. Recently, small portable heart rate monitors have been sold as devices for measuring heart rate. Although this type of heart rate monitor can be carried anywhere, its measurement accuracy is low. For example, even if a driver of a car brings such a heart rate monitor into the vehicle in order to know his/her own health condition, the heart rate measurement must be carried out while the vehicle is stopped. Failure to do so is dangerous. However, for example, on a highway, it is not possible to stop the vehicle while driving, so heart rate measurement cannot be performed. The need for heart rate measurement in vehicles is higher on expressways than on general roads, so if heart rate measurement cannot be performed on expressways, there is little value as an on-vehicle heart rate monitor. Another barometer that can be used to determine a person's health condition is the heartbeat waveform. The heartbeat waveform changes sensitively depending on a person's health condition. However, heartbeat waveforms are complex, and machines cannot simply process them to determine a person's health status. Therefore, current portable heart rate monitors only measure heart rate. The present invention makes it possible to safely and reliably measure the driver's heart rate while the vehicle is in motion, and also records the heart rate measurement results as digital data, making it possible to manage the driver's heart rate information, including heart rate information during driving, after driving. The purpose is to In order to achieve the above object, in the present invention,
Distributed on the wheel or spokes of the steering wheel at least on the right and left sides,
a plurality of heartbeat waveform detecting means, including a light emitting means and a light receiving means arranged close to each other with their optical axes facing the outside of the wheel or spokes, detecting a heartbeat waveform and outputting an electrical signal according to the heartbeat waveform; a plurality of first switch means, each of which is associated with each of the heartbeat waveform detection means, and which is disposed at a predetermined position within the range of the palm including the pads of the fingers; means; analog-to-digital signal conversion means for converting an analog electrical signal from the heartbeat waveform detection means into a digital signal; and memory means for storing digital information; when at least one of the first switch means is turned on, the When the signal output by the heartbeat waveform detection means associated with the first switch means which instructs the detection operation of the heartbeat waveform detection means and is turned on becomes equal to or higher than a predetermined level, the signal is converted into the analog-to-digital signal converter. control means for storing information in the memory means at a predetermined period via a control means, and reading out the information stored in the memory means and outputting it to a predetermined terminal when the second switch means is turned on; . A driver who drives an automobile must always support the steering wheel with at least one of his right and left hands and operate the steering wheel. Furthermore, depending on the driving situation at the time, it is necessary to remove one of the right and left hands from the steering wheel in order to operate various switches such as turn signals, wipers, and lights. Therefore, in order to safely measure heart rate while the vehicle is running, it is necessary to measure the steering wheel while the driver is supporting the steering wheel with either the right or left hand, and whether the driver is supporting the steering wheel with either the right or left hand. It is necessary to enable heart rate measurement. According to the present invention, as the heartbeat waveform detection means, a light emitting means and a light receiving means are used, which are arranged close to each other with their optical axes directed toward the outside of the wheel or spokes.
That is, by arranging the optical axes of the light emitting means and the light receiving means to face a blood vessel such as a finger, the amount of blood passing through the blood vessel can be reduced.
Since the amount of reflected light reaching the light receiving means changes in accordance with changes in synchronization with the heartbeat, the heartbeat waveform can be measured accordingly. Therefore, as long as the driver's one hand is facing one heartbeat waveform detection means, heartbeat measurement can be performed. In addition, there are multiple heartbeat waveform detection means, and they are distributed at least on the right and left sides of the wheel or spokes, so when the driver grips the steering wheel with only his right hand, the heartbeat waveform detected on the right side When the driver grips the steering wheel with only his left hand, the heartbeat waveform detection means placed on the left side can be used, so heartbeat measurement can be performed regardless of whether the driver operates the steering wheel with his right or left hand. Moreover, in the vicinity of each heartbeat waveform detection means,
Since a first switch means is provided for selecting it, if you place your right hand on the right heartbeat waveform detection means, the right heartbeat waveform detection means is selected, and if you place your left hand on the left heartbeat waveform detection means. For example, the heartbeat waveform detection means on the left side is selected, so the selection is substantially automatically performed. While driving, drivers must take their right or left hand off the steering wheel to operate various switches necessary for driving in response to changes in road conditions. Whether it will be on the right side or the left side will depend on the situation at the time. Therefore, the special switch operation for selecting the heartbeat waveform detection means is as follows:
It is relatively troublesome and may interfere with driving operations. However, in the present invention, the heartbeat waveform detection means can be placed at the positions of the right hand and the left hand of a driver who usually holds the steering wheel, and the heartbeat waveform detection means on the right or left side can be automatically selected by simply grasping each position. Therefore, the driver does not need to be particularly aware of the switch operation, and can safely measure the heartbeat without interfering with driving operations. Furthermore, the level of the heartbeat signal detected by the heartbeat waveform detection means changes greatly depending on the state of contact between the detection means and the driver's hand (finger), and particularly when the signal level is small, it is difficult to measure a preferable waveform. Can not. However, when the vehicle changes lanes, for example, the driver needs to operate the steering wheel, so the grip of the steering wheel changes and the contact state between the heartbeat waveform detection means and the finger changes. Furthermore, if the position of the finger does not match well with the heartbeat waveform detection means, the contact condition between the fingers is poor and the signal level becomes low. In the present invention, since measurement of the heartbeat signal is not started unless the level of the signal output by the heartbeat waveform detection means reaches a predetermined level or higher, even if the contact state between the finger and the heartbeat waveform detection means changes, After waiting for the signal level to rise, only heartbeat signals with recognizable waveforms are automatically measured.
Therefore, even if the driver is not particularly conscious of bringing his finger into close contact with the heartbeat waveform detecting means, reliable heartbeat measurement can be performed, and the driver can concentrate on driving. Furthermore, by turning on the second switch means, the heart rate information stored in the memory means can be read out, so after driving the car, an X-Y recorder, printer, etc. You can connect it to visually record the heartbeat waveform while driving, and then show the recording to an expert to determine the driver's health condition. Alternatively, you can connect the output end of the on-board heart rate monitor directly or through a communication line. It is possible to connect to a dedicated computer via the computer and have the computer determine the driver's health status. Therefore,
For example, a transportation company or a taxi company can use this data to intensively manage the health of drivers, thereby preventing traffic accidents caused by physical factors such as driver fatigue. Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1a shows the vicinity of a steering wheel of a type of automobile in which the present invention is implemented. Referring to FIG. 1a, 1 is a steering wheel, 2 and 3 are spokes that support the steering wheel 1, and 4 is a central pad equipped with the main body of an on-vehicle heart rate monitor. The two spokes 2 and 3 are provided with detectors 5 and 6 and switches 7 and 8, respectively. The center pad 4 has switches 9, 10 and light emitting diode indicators 11, 1.
2, 13 and a connector CN for connecting the on-board heart rate monitor to the XY recorder. A cross section taken along line bb in FIG. 1a is shown in FIG. 1b. Referring to FIG. 1b, the slightly inclined surface of the detector 5 is provided with a light emitting diode (ie, light emitting means) PD1 and a phototransistor (ie, light receiving means) PT1. The cathode of the light emitting diode PD1 and the emitter of the phototransistor PT1 are connected to the steering wheel 1 and the shaft (grounded metal) 15 of the spokes 2, 3, and the anode of the light emitting diode PD1 and the collector of the phototransistor PT1 are It is connected to the main body of the on-board heart rate monitor via lead wires 16 and 17. The switch 7 is located close to the detector 5 so that the detector 5 and the switch 7 can be touched simultaneously with one finger. Note that the detector 6 placed on the spoke 3 includes a light emitting diode PD2 and a phototransistor.
Equipped with PT2. FIG. 2 shows a schematic configuration of the electric circuit of the on-vehicle heart rate monitor shown in FIG. 1a. The configuration will be explained with reference to FIG. In this embodiment, a microcomputer CPU is used as the control means. Detector 5
The anodes of the light emitting diodes PD1 and PD2 of 6 and 6 are connected to the output terminal of the oscillator OSC1 via a resistor. The oscillator OSC1 is a 1KHz square wave oscillator, and the oscillation is controlled by the microcomputer CPU. photo transistor
Output ends (i.e. collectors) of PT1 and PT2
is the amplifier via the contacts of relays RL1 and RL2.
Connected to AM1. Relays RL1 and RL
2 are transistors Q1 and Q connected to the output port of the microcomputer CPU, respectively.
Controlled by 2. The output terminal of amplifier AM1 is connected to filter FL1. Filter FL1 is
It is a low-pass filter, or noise filter, that removes frequency components above 1KHz. filter
The output end of FL1 is connected to the detector DT1,
The output end of the detector DT1 is connected to an amplifier AM2 and an A/D converter ADC. The aforementioned light emitting diode indicator 13 is connected to the output terminal of the amplifier AM2. A/D converter
The output end of the ADC is connected to the input port PC of the microcomputer CPU. The light emitting diode indicators 11 and 12 are controlled by transistors Q3 and Q4, respectively, connected to the output ports of the microcomputer CPU. OSC2
is a 500Hz oscillator, and its output terminal is connected to the external interrupt input terminal INT and input port PA of the microcomputer CPU. Switches 9 and 10 on the central pad 4 are connected to the input ports of the CPU via inverters IN1 and IN2, respectively. The connector CN on the center pad 4 has the output end of the D/A converter DAC connected to the output port PB of the microcomputer CPU, the output port of the microcomputer CPU,
and the ground line is connected. The general operation of heart rate measurement will be explained. First, the measurement start switch 10 is operated, and as shown in FIG. 1b, the subject's finger is pressed against the detector 5 or 6 and the switch 7 or 8 is pressed. Now the signal from phototransistor PT1 or PT2 is transmitted to relay RL1.
Alternatively, it is applied to the amplifier AM1 via the contact of RL2. Here, light emitting diodes PD1 and PD2
A 1KHz signal from the OSC is applied to
PD1 or PD2 intermittently emits light to the finger at a frequency of 1KHz. Inside the finger, the amount of blood flowing through the blood vessels changes depending on the pulse. When the amount of blood is large, the light from PD1 or PD2 is reflected by the blood and the phototransistor PT1 or PT
2 and when the amount of blood is small, there is less light reflection, so phototransistor PT1 or PT2
The light reaching is weak. In other words, the phototransistor
At the output end of PT1, a 1KHz signal whose amplitude is modulated in accordance with the pulsation is generated. This signal is
It is amplified by AM1, and noise is removed by filter FL1. The detector DT1 extracts the envelope signal component of the modulated wave, that is, the signal corresponding to the pulsation.
This signal energizes the light emitting diode indicator 13 via amplifier AM2. Also, the digital data corresponding to the level of this signal is transferred to the A/D converter.
This occurs at the output end of the ADC and is applied to the input port PC of the microcomputer CPU. The microcomputer CPU waits until the digital data reaches a predetermined value, then reads the data at a predetermined period and stores it in a memory at a predetermined location inside the CPU. Note that the brightness of the light emitting diode indicator 13 indicates the contact state between the finger and the detector. Figure 3 shows the microcomputer in Figure 2.
An overview of CPU operation is shown. The operation of each step will be explained with reference to FIG. Set the S1 circuit to its initial state. That is,
Open the contacts of relays RL1 and RL2,
The internal register values are set to initial values and the light emitting diode indicators 11 and 12 are turned off. S2 Checks whether switch 10 has been pressed. The switch 10 is a start switch that instructs the start of heart rate measurement. S3 Wait for switch 7 or 8 to be pressed. When switch 7 is pressed, the process proceeds to step 4, and when switch 8 is pressed, the process proceeds to step S5. S4 Switch 7 is pressed, so a high level H signal is applied to transistor Q1, and relay RL
Set contact 1 to "closed". In addition, the left light emitting diode indicator 11 is turned on to confirm the start of heart rate measurement of the left hand. Since S5 switch 8 was pressed, a high level H signal is applied to transistor Q2, and relay RL
Set contact 1 to "closed". In addition, the right light emitting diode indicator 12 is turned on to confirm the heart rate measurement of the right hand. S6 Clear all memories that store heartbeat waveforms to the initial value "0". When the process of step S4 or S5 is completed, an analog signal corresponding to the pulsation is generated at the output terminal of the wave detector DT1. Since the level of this analog signal changes greatly depending on the contact state between the finger and the detector 5 or 6, the subject, that is, the driver, must specify the blinking brightness of the light emitting diode indicator 13 to be in a predetermined state. Adjust the position and finger force. S7 Wait for the specified time To. The time To is the time required for the signal level of the output of the detector DT1 to stabilize after the switch 7 or 8 is pressed. S8 Read the output data of A/D converter ADC with port PC and store the value in register P. S9 Compare the value of register P with constant Po and wait until the contents of register P become larger than constant Po. In other words, since the waveform of the output signal of the detector DT1, that is, the heartbeat waveform changes as shown in Figure 4, by timing the start of waveform data storage with the rising edge of the heartbeat waveform, a large amount of waveform data can be stored in the limited memory. be sure to memorize it. In this example, the A/D converter ADC
Digital data Po corresponding to the level Lp at the input end of is registered as a constant. S10 Set the variable M that specifies the address of the waveform memory to 0. S11 Enables external interrupts, that is, interrupts from the INT end of the CPU. After this, when a predetermined signal is applied to the INT terminal, interrupt processing is executed. In this embodiment, since the 500Hz oscillator OSC2 is connected to the INT terminal, an interrupt is periodically generated once every 2ms. S12 Check whether flag S is 1. The flag S is previously set to an initial value of 0 in step S1, and unless interrupt processing is performed, the flag S will not change to 1 and the process will not proceed to the next step.
Therefore, interrupt processing will be explained next. S30 Increment the value of counter (register) N. S31 Compare the value of counter N with constant 7500. This constant 7500 indicates that the number of samplings for one waveform storage is 7500. S32 Read the level data of the sampled heartbeat signal from the port PC. S33 Store the data read in step S32 in the waveform memory (M) specified by the contents of register M. In the first sampling, M
Since is 0, the data is stored in the waveform memory X(O). S34 Increment the variable M that specifies the address of the waveform memory. S35 Check whether variable M is Mmax corresponding to the end address of the waveform memory. S36 Since the storage of all waveform data is completed, flag S is set to "1". S37 Since the data sampling number has reached 7500, write the code FFH indicating the end of waveform data to the waveform memory (M). S38 Increment variable M. When the above interrupt processing is performed 7500 times at a 2ms cycle, the flag S is set to "1" after a predetermined number of waveform data are written to the waveform memory, so the program exits from step S12 and proceeds to the next step.
Proceed to S13. S13 Disable external interrupts. S14 Reset flag S to “0” and proceed to step
Return to S2. S15 Checks whether switch 9 has been pressed. Switch 9 outputs the heartbeat waveform data stored in the waveform memory, that is, the connector CN
This is a print switch for instructing the start of signal output to. To record a waveform from the heartbeat waveform data stored in the waveform memory, for example, an X, Y recorder is connected to connector CN. An analog signal at a level corresponding to each sampling data and a start signal (trigger signal) instructing to start recording are applied to connector CN, so X,
When you connect the Y recorder and press the print switch, a start signal is first applied to the X and Y recorders, and then an analog signal at a level corresponding to each sampled data is applied periodically, so the sampled The same waveform is recorded by an X, Y recorder. S16 Set the variable M specifying the address of the waveform memory to an initial value of 0. S17 Check port PA and wait for it to become low level L. S18 Check port PA and wait for it to become high level H. Steps S17 and S18 are processes for outputting waveform data at regular intervals in synchronization with the 500 Hz signal of the oscillator OSC2. In other words, one piece of waveform data is output every 2ms. S19 Read the data of waveform memory X(M) specified by variable M and output it to port PB. A level corresponding to this data appears at the output of the D/A converter DAC. S20 Increment variable M. S21 Variable M is the end address of waveform memory Mmax
Check whether the value corresponds to . The processing from step S17 onwards is continued until M=Mmax. This will record 7500 steps of waveform data. Therefore, if a person's heart rate is 60/min (period: 1 second), waveform data for 15 heartbeats can be obtained. Also, the variation in human heartbeat cycle is 3 to 6
%, but in this example, the heartbeat cycle is about 1%.
In the case of seconds, 500 steps of waveform data are recorded per heartbeat waveform, so the degree of variation in the heartbeat cycle can be determined from the recorded data. In the above embodiment, the oscillator OSC operates at the same speed when outputting stored data as when storing waveform data.
Although the data is output in synchronization with the output signal of No. 2, the data output cycle may be arbitrarily changed depending on the conditions of the output device such as the X, Y recorder. Next, another embodiment will be described. In Figure 5,
The configuration near the detector 5 is shown. In this example, the light emitting diodes PD1 of detectors 5 and 6
and phototransistor PT1 are fixed to a sliding key KY supported by a compression coil spring SP. The strength of the spring SP is such that when pressing down the sliding key KY by the amount that it protrudes from the spoke 2, the contact state between the finger and the light emitting diode PD1 and the phototransistor PT1 is favorable for detecting pulsation. It is set so that That is, in this embodiment, when the sliding key KY is pressed down, the contact state between the finger and the key is automatically set to a state convenient for heart rate measurement without adjusting the force of the finger. Therefore, in this embodiment, the light emitting diode indicator 13 for indicating the contact state between the finger and the detectors 5 and 6 and the circuit for driving it, which were used in the previous embodiment, are omitted. FIG. 6 shows an electrical circuit of the on-vehicle heart rate monitor shown in FIG. 5. To explain the configuration with reference to Fig. 6, the comparator
CMP is added and its output terminal is the interrupt input terminal
This embodiment is the same as the embodiment shown in FIG. 2, except that the output terminal of the oscillator OSC2 is connected to the interrupt input terminal INT1. In this embodiment, the microcomputer CPU has an internal timer, and the timer, INT1
It has three independent interrupt lines: INT2 and INT2. 7a and 7b show the operation of the microcomputer CPU of the on-vehicle heart rate monitor shown in FIG. 6.
The operation will be explained with reference to FIGS. 7a and 7b. In the main routine of FIG. 7a, steps S11, S13, and S14 are changed to S11', S13', and S14', respectively, and steps S22, S23, and S24 are changed between S12 and S2.
and S25 are added, and between S21 and S2, S50, S51,
In addition to the addition of S52, S53, S54 and S55,
This routine is the same as the main routine shown in FIG. Also, the interrupt processing of INT1 in Figure 7b is as follows:
The interrupt processing shown in FIG. 3 is the same as that shown in FIG. 3, except that step S31 has been changed to S31'. The operations of the steps previously explained will be given the same step symbols and the explanation will be omitted. To explain the outline of the operation in comparison with the previous example, the number of steps of heartbeat waveform data recorded in the waveform memory after measurement starts is
500 (step S31'), that is, approximately one cycle of the heartbeat waveform. And instead, 500
After recording the waveform data of the step, 15 heartbeat cycles are counted, and the difference in the number of counts for each cycle, that is, the variation in the cycle, is registered in a memory separate from the waveform data. To record data, first read the waveform data and output it, and after a predetermined time, read the period difference data and output it. In other words, waveform data for one heartbeat and period difference data for the following 15 heartbeats are output and recorded. According to this, variations in waveforms and heartbeat cycles can be recorded with a small amount of memory. The operation of each step changed and added in this embodiment will be explained. S11′ Enable INT1 interrupt. INT1 is the same as the above INT. S13′ Disable INT1 interrupt. S14' Reset the flag S to "0" and set the contents of the register M to "0". S22 Enable interrupt INT2 and timer interrupt. Another interrupt at this time
Mask INT1. S23 Wait for flag S to become "1". Flag S does not change unless INT2 interrupt processing is executed, so next timer interrupt and
Let's explain the INT2 interrupt. S40 Increment register N. S61 Check whether the contents of register M are 0, that is, whether this is the first INT2 interrupt. Note that register M has an initial value of 0, and is incremented in step 68 each time an INT2 interrupt occurs. S62 Store the contents of register N in register No. The value corresponding to the time is stored in the register N by the timer interrupt processing in step S40, so the value corresponding to the time at that time is stored in the register N.
The time at which the INT2 interrupt occurred, ie, the time at which the first heartbeat rose from the start of measurement, is stored. S63 Check whether the contents of register M are 0, that is, whether this is the second INT2 interrupt. S64 Store the value of N-No in register Mn.
The value corresponding to the time of the previous interrupt is stored in register No.
Since the time corresponding to the current time is stored in register Mn, the current heartbeat cycle is stored in register Mn. S65 After storing the contents of register Mn in register Mo, store N-No, that is, the current heartbeat cycle, in register Mn. S66 Store the value corresponding to the current time in register No. S67 Stores Mn-Mo, that is, the value corresponding to the difference between the previous heartbeat cycle and the current heartbeat cycle, in the period change storage memory Vd (M) specified by the value of register M. S68 Increment register M. S69 Check whether the value of register M is 17, that is, whether the heartbeat cycle change measurement has been completed. S70 Since the heartbeat cycle change measurement has been completed, flag S is set to "1". When the above INT2 interrupt processing is finished, 15 are stored in the periodic change storage memory Vd (M) (M = 2 to 16).
Heart rate cycle change data is stored. Note that Vd(1)
0 is stored in . S24 Disable INT2 and timer interrupts. S25 Set flag S to 0. S50 Outputs 0 to output port PB and waits until a predetermined time has elapsed. In other words, if a recording device (for example, an X-Y recorder) continuously records heartbeat waveform data and heartbeat cycle change data, a person can look at the recording and distinguish between the heartbeat waveform data and the heartbeat cycle change data. Therefore, a predetermined length of data 0 area is provided between the two data so that the two can be distinguished. S51 Set the contents of register M to 1. S52 Reads the contents of the heartbeat cycle change memory Vd (M) specified by the contents of register M and outputs it to output port PB. S53 Waits for the predetermined time required for the XY recorder to follow changes in the heartbeat cycle. S54 Increment the contents of register M. S55 The contents of register M are compared with the numerical value 17, and if they are not equal, the process returns to step S52 and the next heartbeat cycle change data is output. Heartbeat cycle L and heartbeat cycle variation ΔL,
An outline of the relationship with a person's mental and physical condition is shown in Table 1 below.

[Table] As described above, according to the present invention, the heartbeat waveform data of the driver while driving the vehicle is measured and recorded in the memory, and the data can be read later and used for health management of the driver. Furthermore, as described above, the heartbeat can be measured safely and reliably even by the driver who is driving the vehicle.

[Brief explanation of drawings]

Fig. 1a is a front view showing the vicinity of the steering wheel of an automobile equipped with an on-board heart rate monitor according to an embodiment of the present invention, Fig. 1b is a sectional view taken along line Ib-Ib in Fig. 1a,
Fig. 2 is a block diagram showing the electrical circuit of the on-board heart rate monitor shown in Fig. 1a, Fig. 3 is a flowchart showing the operation of the microcomputer CPU shown in Fig. 2, and Fig. 4 is an example of the output signal of the detector DT1. FIG. FIG. 5 is a sectional view showing the vicinity of the detector 5 of another embodiment of the present invention, FIG. 6 is a block diagram showing the electric circuit of the on-vehicle heart rate monitor of FIG. 5, and FIGS. 7a and 7b. is the microcomputer shown in Figure 6.
This is a flowchart showing the operation of the CPU. 1: Steering wheel, 2, 3: Spokes, 4: Center pad, 5, 6: Detector (heartbeat waveform detection means), 7, 8: Switch (first switch means), 9, 10: Switch (second (switching means), 11, 12: light emitting diode indicator, 1
3: Light emitting diode display, PD1: Light emitting diode (light emitting means), PT1: Phototransistor (light receiving means), CPU: Microcomputer (control means), SP: Spring (elastic member), OSC
1: Oscillator (light emission energizing means), ADC: A/D converter (analog-digital signal conversion means).

Claims (1)

[Scope of Claims] 1. Light-emitting means and light-receiving means, which are distributed on at least the right and left sides of the wheel or spokes of a steering wheel, and which are arranged close to each other with their optical axes facing the outside of the wheel or spokes. a plurality of heartbeat waveform detection means for detecting a heartbeat waveform and outputting an electrical signal according to the heartbeat waveform; each of which is associated with each of the heartbeat waveform detection means, and whose distance thereto includes the pad of a finger; a plurality of first switch means arranged at predetermined positions within the range of the palm of the hand; a second switch means; an analog-to-digital signal converter for converting the analog electrical signal from the heartbeat waveform detection means into a digital signal. means; and a memory means for storing digital information, which instructs the heartbeat waveform detection means to perform a detection operation when at least one of the first switch means is turned on, and which corresponds to the turned on first switch means. When the signal output by the heartbeat waveform detection means exceeds a predetermined level, the signal is
Control means for storing information in the memory means at a predetermined period via a digital signal conversion means, and reading out information stored in the memory means and outputting it to a predetermined terminal when the second switch means is turned on. An on-vehicle heart rate monitor equipped with; 2. The on-vehicle heart rate monitor according to claim 1, wherein the control means counts the number of fluctuations or the period of fluctuation of the signal from the heartbeat waveform detection means within a predetermined time. 3. The on-vehicle heart rate monitor according to claim 1, wherein the control means includes a sensitivity display means for displaying a display according to the amplitude of the signal from the light receiving means. 4. The on-vehicle heart rate monitor according to claim 1, wherein the light emitting means and the light receiving means are fixed to a key supported via an elastic member.