JPS5922537A - Cardiac pulse meter on vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heart rate monitor for measuring a person's pulse, and particularly to a heart rate n1 mounted on a vehicle.

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 will accumulate, your health will deteriorate, and your concentration will decline.

Heart rate is one barometer that can tell us about a person's health condition. As a device to measure heart rate.

Recently, small portable heart rate monitors are on sale.

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 for a long time, so heart rate measurement cannot be performed during that time. The need for heart rate measurement in vehicles is higher on expressways than on ordinary roads, so if heart rate measurement cannot be performed on expressways, there is little value as an on-vehicle heart rate monitor.

The first object of the present invention is to provide an on-vehicle heart rate needle that can measure heart rate with high precision, and the second object is to provide an on-vehicle heart rate needle that can safely measure heart rate by the driver himself while the vehicle is running. "The third purpose is to provide an on-vehicle heart rate monitor that can determine the physical and mental state of the driver, and the fourth purpose is to prevent drivers from falling asleep while driving." be.

In order to achieve the above object, in the present invention, the light emitting means and the light receiving means are arranged near the steering wheel, and the heartbeat is measured by detecting fluctuations in the output signal of the light receiving means. Display or output audio results. In other words, for example, if the light emitting means emits light with the optical axis of the light emitting means and the light receiving surface of the light receiving means facing the same part of a person's finger, the blood stars flowing through the blood vessels of the person's finger will change in synchronization with the heartbeat. Since the amount of reflected light reaching the light receiving means changes accordingly, the heartbeat is measured by detecting this change. According to this,
Since the detection unit is located on or near the steering wheel, the driver can measure the heartbeat while driving while holding the steering wheel.

In one preferred embodiment of the present invention, at least one of an alarm device that emits an alarm sound when the measurement result is outside a predetermined range, and an audio output device that notifies the heart rate by an announcement.
Provide one. According to this, since the presence or absence of an abnormal heart rate can be determined with the ears and there is no need to check the heart rate with the eyes, the heart rate can be safely measured while driving a car on the expressway.

In a preferred embodiment of the present invention, the heart rate and changes in the period between heartbeats are detected from the heartbeat information from the light receiving means, and an alarm is output in accordance with the results.

According to this, the driver's drowsy state can also be determined.

Furthermore, in one preferred embodiment of the present invention, the light emitting means and the light receiving means are fixed to a key supported by an elastic member such as a spring, and when the key is pressed, the state of contact between the finger and the light emitting means and the light receiving means is automatically adjusted. so that it is in a predetermined state. According to this, the contact state between the finger and one light emitting means and one light receiving means can be easily set to a predetermined state without making any special adjustment.

The heart rate may be measured by counting fluctuations in the output signal of the light receiving means, that is, the number of beats within a predetermined time, or by counting the time between each heartbeat, that is, the period.

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, 51 is a steering wheel, 2 and 3 are spokes that support the steering wheel l, and 4 is a central pad equipped with a main body on the on-vehicle heartbeat side. The two spokes 2 and 3 are provided with detectors 5 and 6 and switches 7 and 8, respectively. The center pad 4 has a switch 9. to, a light emitting diode indicator +1, 12.13 and a 3-digit 7 segment light emitting diode 1-indicator 14 are provided.

The Ib-Ib1IA cross section of FIG. 1a is shown in FIG. 1b.

Referring to FIG. 1b, the slightly inclined surface of the detector 5 includes a light emitting diode (i.e., light emitting means) PDI and a transistor (i.e., light receiving means) r) Tl.
It has. The cathode of the light emitting diode PD1 and the emitter of the transistor r-'TI are connected to the steering wheel 1 and the shaft (grounded metal) 15 of the spokes 2 and 3.
The anode of I and the collector of phototransistor PTl are connected to the main body of the on-vehicle heart rate needle through lead wires 16 and 17, respectively. 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 disposed on the spoke 3 includes a light emitting diode PD.
2 and a phototransistor 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 single-deep microcomputer (8048) CI) [J manufactured by Intel Corporation is used.

Light emitting diodes PDl and PD2 of detectors 5 and 6
The anode of is connected to the output terminal of the oscillator O8C via a resistor.

The oscillator O8C is a square wave oscillator with IKI (z), and the oscillation is controlled by the microcomputer CPU. The output ends (i.e. the collectors) of the phototransistors PT1 and PT2 are connected to the amplifier AMI through the contacts of the relays RLI and RL2. Relays RLI and RL2 are controlled by transistors Ql and Q2, respectively, connected to the output port of the microcomputer CPU.

The output end of the amplifier AMI is connected to the filter FLI. Filters F and LL are low-pass filters, that is, noise filters that remove frequency components higher than IK)Iz. The output end of the filter FL I is the detector D'17.
1, and the output terminal of the detector DTI is connected to an amplifier AM2 and a comparator cP1. Amplifier A
The aforementioned light emitting diode indicator 13 is connected to the output end of M2. The output terminal of the comparator CP1 is connected to the external interrupt input terminal INT of the microcomputer CPU. The light emitting diode indicators 11 and 12 are controlled by transistors Q3 and Q4, respectively, connected to the output port of the microcomputer CPU. Switches 9 and 10 on the central pad 4 are connected to the input capo-1- of CI) U via inverters INI and IN2, respectively. VRl and VH2 are variable resistors for setting the upper and lower limits of the heart rate, respectively. The movable pieces of variable resistors VRI and VH2 are
They are connected to input terminals 0 and 1 of the Δ/D converter ADC, respectively. The converted data output terminal and input channel selection input terminal of the A/D converter ADC are connected to the microcomputer CPU.

Switches 7 and 8 on spokes 2 and 3 are respectively connected to input port 1 of the microcomputer CPU. Other boats for CP tJ include Buzzer BZ,
An audio output device VGU and a display circuit DSP are connected. Display circuit DSP latches LAI to 4 hits 1
, LA2 and LA3. It is composed of a multiplexer MPX, a decoder DEC, a counter C01, a digit driver DRI, a segment driver DR2, and a 3-digit 7-segment light emitting diode display 14. The microcomputer CPU and display circuit DSP are BCD (formerly nary
4 lines for passing coded decimal) signals.

Connected by three lines for selecting digits. The output signals of the latches LAI, LA2 and LA3 are applied to the multiplexer MPX, and one of them is selected by the output signal of the counter C○1 and applied to the decoder DEC. The decoder DEC generates a 7 segment signal from the BCD signal. The output signal of the decoder DEC is applied to the segment driver DR2. The segment driver DR2 is composed of seven sets of transistors, and is connected to can-1 of each segment of the light emitting diode display 14.
・Switching to ground or open.

The common anode of each digit of the light emitting diode display 14 is connected to a digit driver DRI. Digit driver II-I
R1 is composed of three sets of transistors, etc., and connects the common anode of any digit of the display I4 to a predetermined potential VCC in response to a signal from the counter Cot. Counter COI is a 3) fat counter and converts the output signal of oscillator O8C.

That is, depending on the three states of the counter CO1, the voltage Vcc is applied to the anode of any digit of the display 14, and the output signal (display data) of the latch LAN, LA2, and LΔ3 is selected. decoder D
A predetermined segment is grounded according to the output of the decoder DEC, and the segment grounded by the segment driver DR2 of the digit selected by the digit driver DRI emits light.

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 first transistor PTI or P
The signal from T2 is applied to amplifier AMI via the contacts of relay R1, ] or RL2. Here, light emitting diode PDI and 1) I) 2 have IK from OSC.
A signal IIz is applied, and P1]1 or PD2 intermittently emits light to the finger at a period of IKIIz. Inside the finger, the amount of blood flowing through the blood vessels fluctuates depending on the pulse. And when there are many blood stars, PDI or P
The light from I) and 2 is reflected by the blood and reaches the phototransistor PTI or PT2, and when the amount of blood is small, there is less light reflection, so the photo1-transistor PTl
The light reaching (or PT2) is - weak. In other words, the first
-1- At the output end of the transistor PTI, a signal of IKI (z) which is amplitude modulated in accordance with the pulsation is generated.
The signal is amplified by the amplifier AMI, and noise is removed by the filter FL1. The detector DTI extracts the envelope signal component of the modulated wave, that is, the signal corresponding to the pulsation. This signal is
The light emitting diode indicator 13 is turned on via the amplifier ΔM2.
to strengthen Further, a binary signal corresponding to the pulsation is generated at the output of the comparator CPI, and this is applied to the external interrupt input terminal IN of the CPU. Microcomputer CP
The LJ measures the heart rate by counting the number of external interruptions within a predetermined period of time. Note that the light emitting diode indicator 13 indicates the state of contact between the detector 5 (or 6) and the finger.

FIG. 3 shows an outline of the operation of the microcomputer CI)U shown in FIG. 2. The operation of each step will be explained with reference to FIG.

81 Set the circuit to the initial state. In other words, the contacts of relays RL+ and RL2 are set to "open J" and the latches [
, set rOJ to AI, LA2 and LA3, and turn on buzzer B7. 1 light emitting diode indicators 11 and 12 are deenergized.

S2 Check switch 10 and wait for it to turn on. Switch 10 is a start switch that instructs the start of heart rate measurement.

S3 Set the input channels of the A/D converter ADC to O and 1, and connect the variable resistors VRI and VR.
The voltage from 2 was A/D converted. Heart rate-Iz limit data and heart rate lower limit data are stored in registers Ml and M, respectively.
Set it to L. Note that the variable resistors VRI and VR2 are set in advance to predetermined states by the driver.

S4 Wait for switch 7 or 8 to be pressed.

When switch 7 is pressed, the process advances to step 5, and switch 8 is pressed.
When is pressed, the process advances to step S6.

S5 Switch 7 is pressed, so transistor Q1
A high level I signal is applied to the terminal, and the contact of relay RL1 is set 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.

S6 Switch 8 was pressed, so transistor Q2
A high level I4 signal is applied to the terminal, and the contact of relay RL1 is set to "closed". Also, to confirm the start of heart rate measurement of the right hand, the right light emitting diode indicator 12 is turned on.

When the processing in step S5 or S6 is completed, an analog signal corresponding to the pulsation is generated at the output terminal of the detector DTI. The level of this analog signal changes greatly depending on the contact state between the finger and the detector 5 (or 6), so the test subject, that is, the driver, must adjust the brightness of the blinking of the light emitting diode indicator 13 to a predetermined state. Adjust finger position and finger force.

87 Wait for a predetermined time of 0. The time Q is the time required for the signal level of the output of the detector DTI to become stable after the switch 7 or 8 is pressed.

S8 Set variable S to 5. This means that heart rate measurements are performed five times in a row.

89 Starts the internal timer of the microcomputer CPU and allows the internal timer to count.

SI0 Enables external interrupts, that is, interrupts by signals applied to the INT terminal.

Check whether Sll switch 9 is pressed. Switch 9 is a cancel switch for stopping heart rate measurement midway.

S12 Since the cancel switch 9 was pressed, interrupts are prohibited, the timer and memory of variables N and M are cleared, the display and instructions are reset, and relays RL + and RL 2 are set to "open". Then, the process returns to step S2.

SI3 Compare variable N with time constant TI. TI corresponds to the time of one heartbeat measurement. The variable N is cleared to 0 when heart rate measurement is started, and is incremented every time there is an internal timer interrupt in step S30.

SI4 Calculate heart rate from variable M and store the result in register Mx. The variable M is cleared to 0 when heart rate measurement is started, and is incremented by one each time there is an external interrupt at the INT end in step S40.

S15 Read the contents of the register Mx that stores the heart rate, and latch it one digit at a time LAI, LA2, and L
Output to A3. Now the 7 segment display 14 shows
The heart rate measurement result is displayed as a 3-digit number.

816 Compare the contents of register Mx with the two-limit setting value of register Ml and the one-do limit setting value of register ML.

S17 Since the heart rate is outside the preset range, scissor BZ is energized for 1 second to issue an alarm.

S1.8 Control the voice output device VGU and make an announcement, "Take a break."

SI9 Disables interrupts and clears the contents of the internal timer and memories N and M to 0.

S20 Decrement the variable S by one.

S21. Check whether the content of variable S is 0. 0
If not, the process returns to step S9 and the heart rate measurement is started again.

822 De-energize the light emitting diode indicators 11 and 12, set the contacts of relays RLI and RL2 to "open", and return to step S2.

S30 Increment variable N by 1-. When this process is finished, the process immediately returns to the original process.

S40 Increment variable M. When this process is finished, the process immediately returns to the original process.

Next, another embodiment will be described. In the fourth part, the configuration near the detector 5 will be shown. In this embodiment, the light emitting diode PDI and the phototransistor PTI of the detectors 5 (and 6) are fixed to a sliding key KY supported by a compression coil spring SP. Spring S
The strength of P 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 PDI and the transistors PTI and transistors 1 to 1 causes a pulse. It is set so that it is in a favorable state for detection. In other words, in this embodiment, the sliding key I (Y
When 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 state of contact 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. 5 shows the configuration of the electric circuit of the car heart rate monitor shown in FIG. 4. Referring to FIG. 5, in this embodiment, the light emitting diode indicator [3] and amplifier AM2 of the previous embodiment are omitted. In addition, in this embodiment, the variable resistors Vl, VR2 and A/D converter ADC are omitted.1. It's shi.

Instead, there are 12 key switches, O and Kl.

K2. K3. K4. K5. K
6. K7. K8. Equipped with K9, KH and KL. These key switches are used to set the upper and lower heart rate limits that determine whether or not an alarm is issued. The other configurations are the same as in the previous embodiment.

6a and 6b show the operation of the microcomputer CPU of FIG. 5. First, the operation will be explained with reference to FIG. 6a. The only difference in FIG. 6a from FIG. 3 is that step S50 and step S;+OO are added. In step 350, the key switch K
O to 9. Check whether KH and KL have been operated.

This is the output capo-hP4. One of P5 and P6 is set to a low level L, the other boat is set to a high level I, and ports 1 to 1 are set to a low level. If at least one of these input ports I- is in a low level L state, it is determined that key power is present.

Step 5100 is a subroutine for setting the upper and lower limits of heart rate according to key operations.

The detailed operation of step 5100 is shown in Figure 6b.

Each step will be explained with reference to FIG. 6b.

S51 Check whether the pressed key switch is KI (K I).

S52: Since the key switch KH has been pressed, the upper limit value input mode is entered. First, the variable N is set to 3, which corresponds to the number of input digits.

853 Wait for the next key switch to be pressed.

S54 Check whether the pressed key switch is KH.

S55 Check whether the pressed key switch is KL.

856 Store the one-digit numerical value corresponding to the pressed key switch in the register RH(N) corresponding to the variable N.

357 Corresponding to the pressed key switch A] Kicked 1
The numerical value of the digit is displayed on the light emitting diode display 14.

S58 Decrement the variable N once by 1-.

S59 Check whether the content of variable N is O.

Until N becomes 0, the operation in the "-limit value input mode" from step S53 is performed.

S60 Check force 1 to see if the pressed key switch is KL.

S61 Since the key switch K[, is pressed, the heart rate lower limit value input mode is entered. First, variable number N is set to 3, which corresponds to the number of input digits.

862 Wait for the next key switch operation.

863 Check whether the pressed key switch is K)-1.

S64 Check force 1 to see if the pressed key switch is K17. S65 Store the 1-digit numerical value corresponding to the pressed key in the register RL (N) corresponding to the variable N.

866 Display the numerical value corresponding to the pressed key switch on the light emitting diode display 14.

S67 Decrement the variable N once.

S68 Check whether the content of variable N is 0.

The lower limit value input mode operation from step 862 continues until N becomes 0.

In the above embodiment, switches for instructing the start of measurement are provided near the detectors 5 and 6, but these switches may also be provided in the central pad 4. Also, for example, by turning on relays RL I and RL2 at predetermined intervals, transistors PTI and PTI are turned on.
Check the level of the signal from T2, and the level is
Switches 7 and 8 may be omitted if the left or right detector is configured to start heart rate measurement when the level indicates that the finger is touching the detector 5 or 6.

By the way, the period of each pulsation changes over a short period of time. For example, as shown in FIG. 7, the cycle at a certain point in time is Ll, and the next cycle changes to L2.

The degree of this periodic change, that is, the variation, is closely related to the degree of tension of one person. Table 1 below outlines the relationship between the average value of general heartbeat cycles, the variation ΔL in heartbeat cycles, and the physical and mental states of a person.

Table 1 Generally, when driving a vehicle, one is physically relaxed and mentally tense.

However, when the driver falls asleep while driving due to fatigue or the like, the mental tension disappears and the heart rate returns to the state during sleep. In other words, referring to Table 1, when a person begins to fall asleep while driving a vehicle, the variation in heartbeat cycles increases rapidly. Therefore, in the next embodiment, a means for preventing drowsy driving is added by monitoring changes in variations in the heartbeat cycle.

FIG. 8 shows an electric circuit according to another embodiment of the present invention. The configuration will be explained with reference to FIG. 8. The configuration of this circuit is the same as the circuit shown in FIG. 2 above, except that the connections of variable resistors VRI and VR2 are changed. In this example, variable resistor vRt is used to set the upper limit of heart rate, and VR2 is used to set the upper limit of heart rate period variation.

FIG. 9 shows the operation of the microcomputer CPU shown in FIG. 8, and FIG. 10 shows the timing of the signal applied to the external interrupt input terminal TNT of the ('; The operation of each step in FIG. 9 will be explained with reference to FIG.

81 Set the circuit to the initial state. That is, the contacts of relays RLI and RL2 are set to "open".

Latches LAI, LA2 and LA3 are set to "0" to de-energize buzzer BZ and light-emitting diode indicators 11 and 12.

Check S2 switch 10 and wait for it to turn on. Switch 1o is a start switch that instructs to start the heartbeat 41 at a constant rate.

S3' Δ/D converter A I) Set the input channels of C to O and 1 and convert the voltages from variable resistors VRI and VR2 to A1) of the heart rate.
1. The data and heart rate variations are limited to 1. The limit data are stored in registers Ml+ and Vl+, respectively.

S4 Wait until switch 7 or 8 is pressed.

When switch 7 is pressed, the process advances to step 5, and switch 8 is pressed.
When is pressed, the process advances to step S6.

S5 Switch 7 is pressed, so transistor Q1
Apply a high level H signal to the contact point of relay RLl.
Close the cellar 1~. Also, in order to confirm the heart rate measurement star 1 on the left hand, the left light emitting diode indicator 11 is turned on.

S6 Switch 8 was pressed, so 1 to transistor Q
Apply a high level ■4 signal to 2 and set the contact of relay RLl to "closed". Also, right hand heart rate measurement star 1~
For confirmation, the right light emitting diode indicator 12 is turned on.

When the processing in step S5 or S6 is completed, an analog signal corresponding to two beats is generated at the output terminal of the detector DTI. The level of this analog signal changes greatly depending on the contact state between the finger and the detector 5 (or 6), so the test subject, that is, the driver, must adjust the brightness of the flashing of the light emitting diode indicator 13 to a predetermined state. Adjust finger position and finger force.

S7- Wait for a predetermined time To. Time]o is the time required for the signal level of the output of the detector DT+ to become stable after the switch 7 or 8 is pressed.

S8 Set 5 to variable S. This means that heart rate measurements are performed five times in a row.

89 Start the internal timer of the microcomputer CPU and enable internal timer interrupts.

Enable SIO external interrupts, ie, interrupts by signals applied to the TNT terminal.

S ], 1 Check whether switch 9 is pressed. Switch 9 is used to stop heart rate measurement in progress.
This is a cancel switch for turning the knob.

Since the cell switch 9 was immediately activated, interrupts are disabled and the timer, variables N, MV, and Vd are set.

NO+ Clears Mn and Mo memory, resets display and instructions, and “opens” relays RLI and RL2.
Then, the process returns to step S2.

813 Compare variable N with time constant TI. TI corresponds to the time of one heartbeat measurement. The variable N is cleared to 0 when starting heart rate measurement and is incremented each time there is an internal timer interrupt in step 530.

814 Calculate heart rate from variable M and store the result in register Mx. The variable M is cleared to 0 when heart rate measurement is started, and is incremented by one each time there is an external interrupt at the INT end in step s40.

S j5 Reads the contents of the register Mx storing the heart rate and outputs it one digit at a time to the latches LAI, LA2, and LA3. The heart rate as a measurement result is now displayed on the 7-segment 1 display I4 as a 3-digit numerical value.

Si6" Transfer the contents of register Mx to register Ml+"
Compare with the plate setting value.

S23 Compare the contents of register ■ with the heartbeat cycle dispersion plate setting value of register Vd. In register V,
As will be explained in detail later, the maximum value of the variation in the heartbeat cycle from the time the timer is started until the period T has elapsed is stored.

S ], 7 Since the heart rate is outside the preset range, activate the buzzer 13 Z for 1 second to issue an alarm.

Si2 The heart rate is greater than the value set in VRI, and the variation in heart rate cycle is greater than the value set in VR2, so
It determines that the driver is drowsy while driving, controls the voice output device VGU, and makes an announcement to ``take a break.''

SL9' Disable interrupts, internal timer, memory N
, M , V HV d , N o , M r+
and clear the contents of MO to 0.

S20 Decrement the variable S by one.

S21 Check whether the content of variable S is O.

If it is not 0, the process returns to step S9 and starts heart rate measurement again.

522 De-energize the light emitting diode indicators 11 and 12, set the contacts of relays RL J and R+-2 to F-open, and return to step S2.

S30: Increment the variable N by 1-1. When this process is finished, the process immediately returns to the original process.

CPU input Ha T N T is at low level 1. When this happens, an external interrupt is generated, and step 540a
Lee.

540a Check the contents of register M. At the time of the first external interrupt, the contents of M are set to O in cell 1, and each time an external interrupt occurs, the contents of M are incremented in step 540j.

540b Set the contents of register V to 0, and store the contents of register N at that time in register NO.

This process is performed when the contents of register M are 0 and 1, that is, at the time of the first external interrupt and the second external interrupt.

540c Check whether the contents of register M are 1.

540d Since the second external interrupt is being processed, the value of N-No is stored in register Mn.

540e After storing the contents of register Mn in register Mo, store the value of N-No in register Mn.

54Of Store the contents of register N in register No.

840g Store the value of M n −M o in register Vd. Before starting this process, register MO has the following information:
The number of internal timer interrupts that have occurred from the time when the external interrupt occurred before the previous time until the time when the previous external interrupt occurred, that is, the previous heartbeat cycle is stored.

The number of internal timer interrupts that have occurred from the occurrence of the previous external interrupt to the occurrence of the current external interrupt, that is, the current heart rate layer jU1 is stored in the register M11. Therefore, register V() contains the difference between the previous heartbeat cycle and the current heartbeat cycle, that is, the change in heartbeat cycle (
variation) is stored.

S40h Compare the contents of register Vd and register V.

5401 Since the current heartbeat cycle change is the maximum value up to that point, the value of register Vd is stored in register V.

540j Increment the contents of register M by 1.

In the embodiment shown in FIG. 8, variations in heart rate and heart rate cycle are set using variable resistors VRI and VR2, but this data may be registered in advance in the ROM, or It may also be set using a key switch as shown in FIG.

As described above, according to the present invention, it is possible to measure the heartbeat without taking your hands off the steering wheel, so that the heartbeat can be safely measured while driving the vehicle. Particularly, according to the embodiment shown in FIG. 8, the driver's drowsy driving state is detected and a warning is issued, which is useful for preventing traffic accidents.

[Brief explanation of the drawing]

Fig. 1a is a front view showing the vicinity of the steering wheel of a type of automobile in which the present invention is implemented, Fig. 1b is a large-scale sectional view taken along line Ib-Ib in Fig. 1a, and Fig. 2 is a view of the device shown in Fig. 1a. FIG. 3 is a block diagram showing the configuration of the electric circuit, and is a flowchart 1 to 1 showing the operation of the microcomputer CPU shown in FIG. 2. FIG. 4 is an enlarged sectional view of another embodiment of the present invention, showing the same part as FIG. 1b, FIG. 5 is a block diagram of the electrical circuit of the device, and FIGS.
These are flowcharts 1 to 1 showing the operation of the microcomputer CII) tJ shown in the figure. FIG. 7 is a waveform diagram showing an example of an electrocardiogram waveform, FIG. 8 is an electrical block diagram showing another embodiment of the present invention, and FIG. 9 is a flowchart showing the operation of the microcomputer CPU in FIG. 8. , Figure 1O is CP
This is a timing chart 1- showing the signal at the INT end of U and the operation timing of the CPU. 1 Steering wheel 2.3 Varnish 4: Center pad 5.6: Detector 7.8.9,1
0: switch 11, ■2: light emitting diode indicator 13: light emitting diode indicator (sensitivity display means) 14: 7 section 1-light emitting diode indicator PDI: to light emitting diode-1 (light emitting means) pTl: phyP h transistor (Light receiving means) C
P U: Microcomputer (control means) S I)
Spring (elastic member) VGU: Audio output device (calculated value output means) BZ: Buzzer (alarm means) DSP: Display amount vJ (calculated value output means) Fig. 4, Fig. 6b

Claims (1)

[Scope of Claims] (1) A light emitting means and a light receiving means arranged close to each other and facing upward on the wheel, spokes, or operation board on the steering wheel; Light emitting energization for energizing the light emitting means to emit light; means; a switch means for instructing the start of heart rate measurement; a switch means for instructing the light emitting energizing means to emit light in response to a change in the state of the switch means, and controlling the number of fluctuations or fluctuation period of the electrical signal from the light receiving means per predetermined time; An on-vehicle heart rate monitor comprising: a control means for calculating a value according to the calculated value; and a calculated value output means for performing at least one of display and audio output according to the calculated value output from the control means. (2) The control means includes an alarm means that compares the calculated value with a preset value and issues an alarm if the calculated value is outside a predetermined range. heartbeat side on the car. (3) The control means includes a sensitivity display means for displaying a display according to the amplitude of the signal from the light receiving means, and (4) the light emitting means and the light receiving means. The on-vehicle heart rate monitor according to claim 1, wherein the means is fixed to a key supported via an elastic member. (5) The on-vehicle heartbeat H according to claim (4), wherein the elastic portion is a spring. Claims (1) and (2) are arranged within the scope of
), (3), (4), or (5)" double-barreled. (7) The light emitting means and the light receiving means are arranged on spokes that support the steering wheel. Claims (1), (2), (3), or (4)
On-vehicle heart rate monitor described in section. (8) Light-emitting means and light-receiving means arranged close to each other and facing upward on the wheel of the steering wheel, the spoke, or the operation board on the steering wheel; Light-emitting means for energizing the light-emitting means to emit light 9 Start of heart rate measurement A switch means for instructing the light emitting energizing means to emit light in response to a change in the state of the switch means, and controlling the number of fluctuations or the fluctuation period of the electric signal from the light receiving means per predetermined time, and the fluctuation period of the electric signal from the light receiving means. An on-vehicle heart rate monitor comprising: a control means for calculating a value according to a change; and a calculated value output means for performing at least one of display and audio output according to the calculated value output from the control means. (9) The control means includes an alarm means that compares the calculated value with a preset value and issues an alarm if the calculated value is outside a predetermined range. On-board heart rate monitor. (lO) The control means issues an alarm when the number of fluctuations of the electric signal from the light receiving means within a predetermined time is less than a predetermined value, and the change in the period of the electric signal is larger than a predetermined value;
The on-vehicle heart rate H1° (II) control means according to claim (9) calculates a value according to the maximum change in period between each variation cycle of the electrical signal from the light receiving means. A car according to claim (8), a heartbeat set.