JPS59120132A - Pulse meter in 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 in particular to a heart rate monitor for measuring a person's pulse.
Viewed on the heart rate monitor mounted above.

When driving a tlL 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 long periods of time without taking a break, fatigue accumulates, your health condition deteriorates, and you experience problems such as a decrease in your mental capacity.

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. Furthermore, even if a driver of a car were to bring such a heart rate monitor into the vehicle in order to know his or her health status, the heart rate measurement would have to be carried out with the vehicle stopped. I don't get it.

In other words, in this type of general heart rate monitor, a light emitting diode, a photodiode, etc. are made to protrude from a substrate to form a reflective photo sensor, and this sensor is placed on the pad of a person's finger. Furthermore, in order to eliminate the influence of external light, the sensor and finger are covered with a black sponge or the like, so the 1-driver cannot be operated with this 1 attached to the finger.

Furthermore, in this type of device, when the finger is moved, the relative positions of the sensor and the finger become misaligned, making accurate measurement impossible, but it is not possible to check whether the measurement is being performed correctly. To confirm this using conventional equipment, the subject repeats the measurement many times while changing the finger position, grip force, etc., and then determines the most reasonable (average p) value. There is no way to make it a true value. However, this method takes a very long time to accurately measure the heart rate, making it impossible to reliably measure the heart rate within a short period of time, such as when a vehicle stops at a traffic light. If it takes a lot of time, it becomes extremely troublesome for the driver.

The first object of the present invention is to provide an on-vehicle heart rate monitor that can accurately determine the heart rate (Klll) and check whether the heart rate (Klll) is at a negative I1. A second object of the present invention is to provide a car-1 heart rate monitor that can be used in a car.

In order to achieve objective 1 above, in the present invention, a display device capable of two-dimensional display, such as a cathode ray tube display device, is arranged in the front panel, instrument panel 1, steering wheel center pad 1, etc. , display the detected heartbeat waveform. According to this, if the correct <all settings are performed, the heartbeat waveform of ゛ will be cursed, but if the position of the finger and the sensor is misaligned, the displayed waveform will be distorted, so The operator or measurer can immediately check the reliability of the a1 value.

In one preferred embodiment of the present invention, the display means is a display device such as a rask scanning type that constantly scans the entire surface, and is equipped with an image memory corresponding to each pixel on the display surface,
According to the quantized data of the heartbeat waveform signal, data corresponding to the waveform is stored in a predetermined image memory, and the data in the image memory is read out at a predetermined scanning timing to create a waveform table.
Display data. According to this, unless the image memory is cleared or rewritten, the heartbeat waveform will not be displayed.I1. Since this continues, a detailed check of the heartbeat waveform can be performed without having to maintain the d1 steady state for a long time.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Figure 1 shows the ! of the present invention! 1 shows the vicinity of the driver's seat of a vehicle with a heartbeat R1. This will be explained with reference to FIG.

The central part of the steering wheel 4 is equipped with a star l to switch switch SW1 for instructing the start of heart rate measurement, a cancel switch SW2 for canceling the measurement, and light emitting diodes I and ED for displaying information according to the heart rate. .

There are two cathode ray tube display devices cRT1 and CR1"2 on the left side of the steering wheel 4. What the driver 1 wears on his finger is a heart rate detector 2, which has a cord that connects it to the heart rate monitor itself. 3 is placed with a little extra length so as to fit along the arm of the driver 1.The cork 3 is fixed to the clothes of drivers 1 to I with chestnut knobs 5.

Figures 2a, 2b and 2c show heart rate detection 71 temporary 1.
The configuration of κ2 is shown. This heartbeat detector 2 consists of a board 2a, 2l) manufactured by Plus Sennoku, a holding cotton tape 2c, and a light emitting diode 1. D, NO]~Transis 9PT and coat 2d. The negative end of the cotton tape 2c is the substrate 2a.
As shown in Figure 2b, the board 2a is placed on the side of the fingernail la, the cotton tape 2c is wrapped around the finger, and the other end is engaged with the - end to secure it. ing.

The substrate 2a and the gols 2b are formed into curved surfaces that match the shape of the claw 1a. The light emitting diode l4[) and phototransistor I)1 are embedded in the rubber 2b so that the claw 1a, the rubber 2b, the light emitting diode LD and the phototransistor I)1' are in close contact with each other, and the light emitting diode l4[) and phototransistor I)1 are embedded in the rubber 2b so that the surface of the rubber 2b and the phototransistor I)1' are in close contact with each other. The diode LD and the tip of the transistor PT are aligned with each other. Also I. I)
and the optical axis of the PT or the I. D
and PT are arranged.

Since human fingers are relatively soft, when gripping an object (for example, a steering wheel) with the fingers, the shape of the kneading changes by f+13. Therefore, in heartbeat detection that detects the reflection of light by blood, if force is applied to the finger, the position of the surface tube and the sensor will shift, causing an error in the detection output. However, as shown in Figure 20, when adding a sensor part to the fingernail side, a large force is not generally applied to the fingernail side of two people's fingers, and the fingernails are relatively hard, so the rubber 2b and claw 1a
If they are in close contact with each other, detection errors will not occur unless there is an extreme case.

FIG. 3 shows a schematic configuration of the heart rate monitor installed in the vehicle 1 shown in FIG. This will be explained with reference to Figure 3.

In this embodiment, a microcomputer CPU is used as the control device. Star 1/Swiss SW1 and Gancel switch SW2 are connected to C through an imperter etc.
It is connected to input port 1 of PLJ.

AI)C is an analog/
There is a digital converter, and input channel 1 has a variable resistor! ! }The VRI is connected to the human input channel 2 with a variable resistor VR2, and the heartbeat signal to be detected is applied to the input channel 3. -1- It sets the limit value,
VR2 is for setting the lower limit value of heart rate.

A buzzer I37 for outputting a report and a voice synthesizer VGU are connected to the output baud 1- of the C:PU. SP Ke Subika. CRT] and CRT
Video memory, VRAMI and V
The RAM 2 is connected to the microcomputer CPU.

The light emitting diode +:ro of the heartbeat detector 2 includes 1.
An oscillation circuit OSCI that outputs a signal of 5Kilz is connected. The output of the transistor PT is sent to the amplifier circuit AMP+, the filter FT-, 1, and the detection circuit f-a.
DT] to the human power channel 3 of the analog/digital converter ADC. The filter F1-1 is ]. There is a low-pass filter 'C that removes signal components of 5 Kllz or more. The light emitting diode r-En for display is amplified! j: Connected to the output end of the detector nTl via AMP2. The oscillation circuit ○SC2 is provided for time measurement, and its output terminal is connected to the microcomputer C.
Connected to the PLJ's interrupt terminal ■NT.

FIG. 4 shows the configuration of the video feed VT<AMI in FIG. 3. Note that the video memory VRAM2 also has the same configuration as VRAMI. This will be explained with reference to FIG.

The brightness/n;
&: Connected, and a memory address is selected according to either the count 1 to value of the address counter CO applied to the inputs Δ and B of the MX, or the output address of the CPU.

This selection is made by the microcomputer CPU, and the memory RA. When inserting data into M or reading data from RAM. Specify MX's Hachiroku 13, and the CPU specifies A1 Jerez.

At other times, the memory R. The address of AM is specified by A1 and the counter 1 value of the response counter CO.

The AI-less counter CO is from the generator Osc3.
Counting from 1 to 1 is always performed using a pulse number corresponding to the number of pixels. Further, a synchronizing signal generating circuit 100 is connected to the output terminal of the address counter CO, and every time M generates a vertical synchronizing signal and a horizontal synchronizing signal at a predetermined timing according to the value of the counter 1 of the CO. occurs.

The data lines of the memory RAM are
A shift 1 register SR is connected, and the serial output terminal of SR is connected to the signal synthesis circuit 110. Further, a data line of the CPU is connected to this data line via a bidirectional path sofa BF2.

When displaying a predetermined pixel on a cathode ray tube brightly, set a predetermined bit 1 to "1" in the RAM address corresponding to that pixel.
” is written from CPTJ. In this case, specify B input k of multiplexer MX, and write bidirectional buffer T.
Specify the CPU side of 3F2 as input and the RAM side as output,
Specified data is input to the address line and data line of the CPU, and a write designation signal is applied to the memory I/M. After the end of this operation, MX is designated as input 8 and the RAM side of the bidirectional vanofer 13F2 is set to high impedance until the next sushi-in is performed.

In this state, a synchronization signal is generated at each predetermined timing, and the RA. Addresses 1 to M are sequentially selected. When a predetermined address is specified by writing display data, multiple bits of data including pixel data are stored in the shift register SR, and after a delay of a predetermined clock corresponding to the pixel position, the "bright" state of the predetermined pixel is indicated. Data is a signal synthesis circuit! 10 is applied. In this way, serial data corresponding to the data of all pixels on the display screen is continuously output, and this image data and the synchronization signal are synthesized at 110 to form a composite equal signal. monitor TV) in Figure 5, microcomputer CPH in Figure 3]
Demonstrates counter-articulation motion. The operation will be explained with reference to FIG.

First, interrupt processing will be explained. Since the signal from the oscillation circuit OSC2 is applied to the interrupt terminal INT of the CPU, the CPU executes interrupt processing at predetermined intervals.

In this interrupt processing, the contents of register N are incremented by one.

In other words, the contents of register N change depending on the elapsed time, so if you clear the contents of N to O at a certain timing, by checking the value of N in the main routine, you can check the elapsed time since clearing. It costs. In the main routine, subroutine, etc., various processing timings are determined by checking the value of this register N.

Next, the main routine will be explained. When the power is turned on, first press the start switch SWl. When this is turned on, the voltage set by variable resistors VRI and VR2 is converted into a digital signal by ΔDC, and the converted data is sent to registers Ml+ and MLL. Registers Ml+ and M1. The data becomes the heartbeat cycle variation-1 limit value and the heart rate lower limit value, respectively, for determining whether to issue an alarm.

Table 1 below outlines the relationship between the general average value of heart rate 1/+, the variation in heartbeat cycle ΔD, and a person's physical and mental state.

-Generally, when driving a vehicle, one is physically tense 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. That is, referring to Table 1, when one falls asleep while driving a vehicle, the variation in heart rate (t)1 suddenly increases.

In this embodiment, a heartbeat cycle variation upper limit MH and a heart rate lower limit Ml+ are set, and an alarm is issued when both exceed the set value of 1 shift.

After completing the settings of Ml1 and ~■[, L'?
) to start heart rate measurement. The heartbeat measurement subroutine will be explained in detail later. When the heartbeat 81 is constant or finished, the heartbeat cycle minutes 11, that is, the dispersion Δ1, are calculated based on the result. This calculation (where S is the heartbeat cycle of J predetermined samples (16 in this example)) is performed using the following 81 formula.

Variance = average value of s2 - (average value of S) 2 Next, the heart rate, that is, the heart rate per minute, is calculated from the average value of S. Depending on this result, the RO in the CPU is
Read out the predetermined numerical display data stored in M (read-only memory) and transfer it to the video memory VRAM2.
Set 1 to the specified address. As a result, for example, as shown in FIG.
Displayed on RT2.

Next, the A/D converter ADC samples the heartbeat signal at predetermined intervals for a predetermined time, and displays the sampled data as a waveform on the cathode ray tube display device CRTI. Furthermore, is this display performed? i, memory RAM in advance
Clear. In the display processing, the following processing is performed.

As shown in FIG.
A subroutine (not shown) is executed to set predetermined bits 1 to 1 at a predetermined address in the memory RAM to ``1''. Specify the voltage OV at a predetermined y* mark (for example, 10) and change the specified Y coordinate according to the value of the sampled data 6
For example, voltage 0. When changing the Y coordinate by →-10 for each IV, if the sampled voltage is 1.5 cm, the specified Y coordinate will be 25 (10+15). The X coordinate has an initial value of 0 and is changed by +1 every 5 samplings.

That is, when this process is performed, pixels at the Y coordinate corresponding to the voltage are sequentially displayed brightly from the left side of the screen to the right side. This process is performed until the X coordinate reaches the right end, that is, X=XM. As a result, a heartbeat waveform as shown in FIG. 6 is displayed on the display CRTI.

It is checked whether the cancel switch SW2 is on, and if it is off, the next process is performed. The variance △I, is larger than the content of the resistor Ml+, and the heart rate 1/
If I, is smaller than the contents of register M1, there is a high possibility that the driver is drowsy, so the buzzer BZ is energized for one second, the voice synthesizer VGLJ is instructed, and the speaker ST3 is activated.
"Take a break," the voice outputs at 17. If the above two conditions are not met, only the heart rate and heartbeat waveform are displayed.

Next, the heart rate measurement subroutine will be explained. Note that this subroutine uses +y number of registers such as R20 specified by the contents of registers A, Rl, and 0.

First, clear the memory (register) and read the heart rate signal 3kΔD.
Sampling is performed every 2 mSe ('.) at C. Check whether a T wave has arrived, and if it is an I wave, then check whether it is the peak of the signal.

The R wave is a large mountain part of the heartbeat signal, and in this example, the differential value, that is, the change in data at each sampling, is checked to see if it is thicker than a predetermined value, and the R wave is determined to be large for a predetermined number of times in a row. It is determined that it is an R wave only when Also, in this example, the change in sampling value is 0
It is determined that the current peak is reached when the peak temperature is lower than or equal to that level twice in a row.

Once you know the peak, change the contents of counter N (timer) to O.
2, and measure the time (I,) from peak detection to next peak detection. This time is the so-called RR interval (heartbeat cycle). Each time ill determination is performed, the contents of register A are counted up, and each measurement result is stored in register R2 (Δ).

When data for 16 waves is obtained (when A=16)
, end the measurement. As a result, 16 cycles of cycle data are stored in the 16 1-noister registers of register R2(A). Therefore, the variance value and heart rate data are obtained from the contents of this register by performing the above processing.

Next, another embodiment of the present invention will be described. This will be explained with reference to FIG. In this embodiment, a surface display device CRT
An oscilloscope is used for I, and the detection E+l")'p
] through the amplifier AMP2 (,, through the CRTl
horizontal human power (X-axis input). In addition, a comparator CPi is connected to the output of the detector Di', and I)
The output of TI is immediately converted into a binary signal, and this 21u'f
The signal is configured to be applied to the microcomputer cP[1. Therefore, in this example, the R-R interval, that is, the heartbeat cycle, is measured by setting t1, the time from one rising edge to the next rising edge of the binary signal from the comparator Cp. . The heart rate is displayed on the cathode ray tube display CRT2 as in the previous embodiment.

In the embodiment described above, two cathode ray tube display devices 1d are used, and the heartbeat waveform is displayed on one side, and the heart rate is displayed on the other side.For example, the heart rate can be displayed numerically. Alternatively, a plurality of 7-segment displays may be provided and used instead, or the waveform and heart rate may be displayed superimposed on a display for displaying the heartbeat waveform, or instructions may be provided using a switch. Alternatively, a configuration may be adopted in which the waveform and heart rate are switched and displayed at a predetermined frequency +411.

As described below, according to the present invention, the heartbeat waveform during measurement is displayed on the screen display, so it is easy to check whether Hil1 determination is being performed accurately, and the measurement can be completed in a short time. sell.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the vicinity of the driver's seat of a vehicle equipped with the on-vehicle heart rate monitor of the present invention. 2a is a plan view showing the heart rate detector 2 of the on-board heart rate monitor mounted on the vehicle shown in FIG. 1, FIG. IIC of figure 2b
-IIC line sectional view. Figure 3 shows the heart rate monitor 41 installed on the vehicle shown in Figure 1.
1111. '! FIG. 2 is a block diagram showing the configuration. FIG. 11 shows J++ of the video memory VRAMI in FIG.
It is a Bronok diagram showing ¥ composition. FIG. 5 is a flowchart 1 showing the general operation of the microcomputer CP{I of FIG. 3. FIG. 6 is a W-side view showing a display example of the CRTI screen of the display device. FIG. 7 is a block diagram showing another embodiment of the present invention. 1:1 Heliver 2: Heartbeat detector (heartbeat detection means) 2a: Basic 2b: Got1 2c: Cotton tape 2d (3): Code 4; Steering wheel 5: Clip SWI: Star 1 ~ Switch (switch means) SW2 :
Cancel switch CRT]. , CR Go2: Braun tube display device (surface display means) OSCI: Oscillator circuit (light emitting energizing circuit) LI); Light emitting diode (light emitting means) Y) Go: For 1 to 1 to transistor (light receiving means) cIfT
J: Microcomputer VRAM]. VRAM2: Video memory rrr-i: Low-pass filter 1') Tl: Detector -197- -198- -199-

Claims (4)

[Claims] (1) Heartbeat detecting means comprising a light emitting means and a light receiving means; a light emitting energizing means for energizing the light emitting means; a switch means for instructing the start of heart rate measurement; and a display means; , an electronic control device for displaying at least one of a numerical value and a waveform on the surface display means in response to an electrical signal from the heartbeat detection means; (2) The surface display means is a surface scanning type display device that displays an image by scanning the display surface in two directions at i and r times, and the electronic control device analyzes the electrical ID from the light receiving means. The scope of the above-mentioned claims further comprises performing digital conversion, storing the converted data in a predetermined image memory, and outputting the data from the image memory to the surface display means at a predetermined timing that matches the scanning timing of the surface display means. The on-vehicle heart rate needle described in paragraph (1). (3) The display means scans the display surface in only one direction, and changes the display position in the other direction according to the electrical signal level from the heartbeat detection means output from the electronic control device. Range of Item (1) [1 (11 Heart rate monitor). (4) The screen display means is double-sided, one of which displays the heartbeat waveform, and the other of which displays a numerical value according to the heartbeat signal. (2) The vehicle described in paragraph (3) above - Heart rate monitor.