JPS60116327A - Heart rate measuring apparatus - 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] [Technical field] The present invention relates to a heart rate measuring device.

[Prior Art] Medical heart rate measuring devices are well known in the past. However, this type of equipment is relatively difficult to handle and expensive, so it cannot be used regularly by the general public.

Therefore, recently, an inexpensive and easy-to-handle portable heart rate measuring device has been developed and commercially available, which uses LSI or the like and incorporates an electronic circuit into a case about the size of a notebook.

This type of portable heart rate measuring device detects fluctuations in blood flow rate according to pulsations based on the intensity of light reflection, and measures the number of fluctuations. The detection unit is configured to have one light-emitting element and one light-receiving element slightly tilted relative to each other so that the optical axis is directed to a predetermined position, and is worn on the finger. Additionally, in order to eliminate the influence of external light, it is necessary to wear a light-blocking cover on the finger.

With this, the detection unit has a simple configuration, but it can reliably measure the heartbeat.

However, in this type of heart rate measuring device, the detection unit must be attached to the finger, so it is necessary to continuously monitor the heart rate while working, such as monitoring changes in heart rate during work of a typist who uses his or her fingers all the time. It cannot be used for purposes such as health management that measures

[Objective] An object of the present invention is to make it possible to measure a heartbeat in a working state by measuring the heartbeat without attaching a detection unit to a finger.

[Structure] For example, if you look at the example of a wristwatch, it is clear that adding a small device will not have a negative effect on the work. Therefore, the problem can be solved if heartbeat signals can be detected in the arm. However, in the arm area, blood vessels are not concentrated in shallow areas from the surface of the finger, so simply attaching the conventional detection unit to the arm will not allow detection unless the position of the detection unit matches the position of the blood vessel. However, positioning is difficult.

Therefore, in the present invention, the optical axes of the light emitting means and the light receiving means are oriented in substantially the same direction, and at least two light receiving means are used, and the light receiving means are arranged so as to sandwich the light emitting means. According to this, the sensitivity is high because there are multiple light receiving means,
Heartbeats can be detected even if the reflected light is weak.

When measuring heart rate while working, if the detector worn on the arm or the like is connected to the main body of the device by a wire, the work will be hindered.

Therefore, in one preferred embodiment of the present invention, the detection unit is provided with a transmitter that emits radio waves, and the device main body is provided with a receiver that receives the signals and demodulates the signals, and the detection unit and the device main body are connected by radio waves. , eliminate the line.

Hereinafter, the present invention will be described in detail with reference to the drawings.

3- Figures 1a, 1b and 1c show the appearance of the heartbeat detection unit. This will be explained with reference to FIGS. 1a, 1b and 1c. This heartbeat detection unit includes a band-shaped support member 100 and a case 200 containing a transmitting device (10). Reflective optical sensors SEI and SF3 are arranged at a distance from each other on the inside of the support member 100, that is, on the side that comes into contact with a person's hand.

Each optical sensor SEI and SF3 consists of one light emitting diode LEI (or LE2) and four phototransistors PTI, PT2 . PT3 and PT4
(or PT5 to PT3). Light emitting diodes LEI and LE2. Phototransistor PTI~PT
8 have their respective optical axes oriented perpendicularly to the support member 100, and even when this unit is worn on a person's hand as shown in FIG. The configuration is such that the optical axis of the phototransistor and the optical axis of the phototransistor point in the same direction (that is, the optical axes are parallel to each other).

The lead wires 101 and 102 of the optical sensors SEI and SF3 pass through the inside of the support member 100 and are connected to the case 2.
Connected to 00. At both ends of the support member 100,
Cotton tapes 100a and 100b are provided, respectively. Wrap the supporting member 100 around your hand and attach cotton tapes 100a and 1.
By engaging 00b with each other, the heartbeat detection unit is fixed as shown in FIG. 1c.

FIG. 2 shows the circuit configuration of the electronic circuit (transmission device 10) and optical sensors SEI and SE2 built into the case 200. This will be explained with reference to FIG.

The light emitting diodes LE1 and LE2 of the optical sensors SEI and SF2 are connected in series, and the phototransistors PTI to PT8 are connected in parallel. The light emitting diodes LEI and LE2 are connected to the oscillation circuit O8 via the driver.
Connected to the output of CI. In this example, 1 oscillation circuit 0
8CI generates a pulse signal of IK+Iz. Therefore, the light emitting diodes LEI and LE2 are publicly lit at a period of 1 m5ec.

When the optical sensor SE1 or SF2 is positioned facing a human blood vessel, the light reflectance of that portion varies depending on the blood flow rate, that is, the heartbeat.

Therefore, an IKHz AC signal having a level corresponding to the heartbeat signal is obtained at the output terminals of the phototransistors PTI to PT8.

The output signals from phototransistors PTI to PT8 are
Amplifier AMI, low pass filter LPI.

Amplifier AM2. Low pass filter LP2 and amplifier A
The signal passes through M3 and is converted into a heartbeat signal as shown in FIG. This heartbeat signal is applied to an AM (amplitude modulation) modulator AMM. At one end of the modulator AMM is an oscillation circuit 08CI.
A signal of IKl+z from is applied, and this signal is converted into a sine wave by a filter and then amplitude-modulated according to the level of the heartbeat signal. The output signal of the modulator AMM passes through an FM (frequency modulation) modulator FMM, passes through a power amplifier PA, and is radiated from a transmitting antenna as a radio wave.

The heartbeat signal has a very low frequency of about I Hz, and it is difficult to transmit it as is on radio waves because the signal must be demodulated on the receiving side. Therefore, in this embodiment, the heartbeat signal is amplitude-modulated and converted to a relatively high frequency of IKHz, and then frequency-modulated and this signal is carried on radio waves.

FIG. 4a shows a circuit configuration of a data receiving unit that receives signals from the heartbeat detection unit (transmission device 10) and performs various processes. This will be explained with reference to FIG. 4a. In this embodiment, the data receiving unit is configured to be able to simultaneously process signals from six heartbeat detection units. That is, six FM receivers RX1, RX2 . RX3. RX4. RX5 and R
Each X6 is tuned to a different frequency and can receive different radio waves. Therefore, if the frequencies of the radio waves emitted by the six heartbeat detection units are set to the reception frequencies of the FM receivers RXI to RX6, different heartbeat detection units 7- You can get the signal from

Since the FM receivers RXI to RX6 demodulate the frequency modulated signals, a 1 KHz signal whose amplitude is modulated by the heartbeat signal is obtained at their output terminals. each F
AM demodulator D is connected to the output terminals of M receivers RXI to RX6.
EMI to DEM6 are connected. AMtjllII
The amplifiers DEM1 to DEM6 are connected to the amplifiers AM4 . Lowpass Fi JL/Evening LP3. amplifier AM5
．． Low pass filter LP4. It consists of an amplifier AM6 etc. A heartbeat signal detected by each heartbeat detection unit is obtained at the output terminal of each AM demodulator DEM1 to DEM6.

The output signals of the AM demodulators DEMI to DEM6 are applied to different input channels of the A/D converter ADC. The A/D converter ADC is a microcomputer CP
Connected to U. A key switch unit KSW, memory RAM, video RAM, etc. are also connected to the microcomputer CPU. A display CRT8- is connected to the video RAM. In addition, so that this unit can be connected to other processing equipment, we have installed a 5TB (strobe) from the CPU.
, DATA, BUSY and A
A CK (acknowledge) signal line is drawn out.

The key switch unit has seven key switches SWI.
, SW2. SW3. SW4. SW5. SW6 and SW
It is equipped with 7. Key switches 5W1 to 8W6 are used to specify channels 1 to 6, respectively, and key switch SW7 is used to give an instruction to output collected data to an external device. , microcomputer CP
The schematic operation of U is shown. This will be explained with reference to FIGS. 5a and 5b. When the power is turned on, first, the output port is set to the initial level, the memory RAM and video RAM are cleared, predetermined data is written to the video RAM, and the status of operation is displayed on the display CRT. Also, all flags are cleared and the counter has an initial value of 1-
be done.

Perform a key scan and wait for key power. Furthermore, an interrupt is generated by an internal timer at very short predetermined intervals.

When this interrupt occurs, flag F2 is set to 1. When flag F2 becomes 1, after clearing F2 to 0,
Flag F3 (C) (C is the content of counter C: C = 1 to 6
), if it is 1, the heart rate measurement subroutine is executed, and if it is 0, this subroutine is skipped. Counter C is incremented by 1, and if C) Cmax (Cmax is 6 in this example), the contents of C are set to 1.

In other words, each time a timer interrupt occurs, channel 1 is
~6 and perform heart rate measurements on them. However, heart rate measurement is actually performed when the flag p 3 (c) of each channel is 1.

Flag F 3 (C) is cleared to 0 in the initial state.

Key switch SWI, SW2. SW3. SW4゜SW5
Alternatively, when SW6 is turned on, the flag F 3 (C) associated with each changes.

That is, for example, when the key switch SW2 is turned on while the flag F 3 (2) is 0, the flag F 3 (2)
is set to 1, and a heartbeat measurement subroutine is executed for the heartbeat signal of channel 2 (output signal of AM demodulator DEM2) once every six timer interrupts. Therefore, each key switch SWI, SW2 . S
W3. SW4. By operating SW5 and SW6, it is possible to instruct the start and end of measurement for each measurement channel], 2, 3, 4, 5, and 6.

The heart rate measurement subroutine processes as follows.

Each time this subroutine is executed, the counter T (C) is incremented by 1. This counter T (C) holds the value of the time (time from the previous peak) in each heartbeat cycle (from peak to peak of the signal) for each channel. Sample the heartbeat signal of the specified channel and read the A/D converted data. The previously sampled value and the current value are compared to check the differential value dv/dt.

If this differential value is larger than the constant Kr, it is determined that the R wave (the waveform component detected when measuring heart rate: 11-the mountain part in Figure 3) has arrived, and the flag F1 is set to 1. set. When the flag F1 becomes 1, the next step is to wait until the differential value d■/dt becomes 0 or less. Immediately after the differential value becomes O or less is the timing of the peak of the R wave.

When this peak is detected, flag F1 is cleared. Since the time from peak to peak is one cycle, the content of the counter T (C) that holds the time from the previous peak to the present is the time of one cycle. The contents of this counter T (C) are stored in one cycle data memory M (C, P). Parameter C is the channel, P is the wave number (p==Q-Pmax
: In this example, P max is 15). After storing the data, counter P is incremented by 1 and counter T (C) is cleared. That is, when heart rate measurement is started, cycle data memories M(C,0) to M(C).

Pmax), periodic data is stored in sequence.

When the wave number P becomes Pn+ax, the periodic data memory M(
Read the data of C, 0) -M (C2Fmax),
The average heart rate is calculated and the result is stored in the heart rate data memory D (
C, S).

Store in. Parameter C is the channel, and S is the number of 12-bars. The counter P is cleared to O, the measurement number counter S is incremented by 1, and the obtained heart rate and its channel are displayed on the display CRT. Therefore, 16 of the heartbeat waveform
The average heart rate is measured for each wave, and the results are sequentially stored at predetermined addresses in the memory D (C). Note that when the number of measurements S reaches the maximum value determined according to the memory capacity,
S is cleared to 1.

When the key switch SW7 is turned on, a data output subroutine is executed. Note that when performing this operation, the signal lines STB and D of the microcomputer CPU are connected in advance.
A data processing device equipped with a predetermined interface circuit is connected to ATA, BUSY, and ACK.

The data output subroutine processes as follows.

First, perform a key scan, then switch the key switches SWI to SW.
Wait until one of 6 turns on. When any one of SWI to SW6 is turned on, the value of the channel associated with it is set in a counter (register) C, and a measurement number counter S is set to 1.

Next, read the contents of the heartbeat data memory D (C, S),
Wait until the signal BUSY disappears, that is, until the external device becomes ready to receive data. If reception is possible, D(C,
The heart rate data read from S) is set to the output port (DATA line), and the strobe signal STB is output. When the reception completion signal ACK arrives from the external device, the measurement counter S is incremented by 1, and this operation is repeated until S=Smax. S rnax is the value of S of each channel before data output.

Therefore, the collected heart rate data is stored in the key switch S.
By turning on W7, each channel is sequentially input to an external device.

In the above embodiment, two optical sensors (SEI and 5E2) are arranged at positions apart from each other, but a single set of optical sensors or a larger number of optical sensors may be used. Further, although the embodiment shows a case in which only the heart rate is measured, it is also possible to adopt a mode in which variation in the heartbeat cycle, that is, variance, is measured at the same time. The variance can be determined by the following equation, where S is the heartbeat cycle data of a predetermined sample.

Variance = Average value of 82 - (Mean value of S) 2 [Effect] As described above, according to the present invention, the heart rate can be measured by attaching the heart rate detection unit to the arm or the like that does not have a negative effect on work, so it is possible to measure the heart rate in practice. It can be used for health management and other purposes that require measuring heart rate data during work. In particular, by separating the detection part and the device body and wirelessly transmitting the heartbeat signal as in the example, the device becomes smaller and there is no wiring connecting the detection part and the device body, making the person being measured feel uncomfortable during the measurement. No more giving.

[Brief explanation of drawings]

Figure 1a is an embossed plan view of the heartbeat detection unit of the embodiment, Figure ib is a sectional view taken along line Ib-■b in Figure 1a, and Figure 1c is a perspective view showing the heartbeat detection unit worn on a person's hand. It is. FIG. 2 is an electrical circuit diagram showing the configuration of the electronic circuit inside the case 200 of FIG. 1a. FIG. 3 is a waveform diagram showing an example of a heartbeat signal waveform. FIG. 4a is a block diagram showing the circuit configuration of the main body of the device that receives the signal from the heartbeat detection unit, and FIG. 4b is an electric circuit diagram showing one configuration of the AM demodulator shown in FIG. 4a. FIGS. 5a and 5b are flowcharts showing the general operation of the microcomputer CPU shown in FIG. 4a. 10: Transmitting device (signal transmitting means) 100: Support members 100a, 100b: Cotton tape 101, LO2: Leading line 200: Case SEI, SF3: Optical sensor LEI, LEI: Light emitting diode (light emitting means) PTI
, PT2. PT3. PT4. PT5. PT6. PT7.
PT8: Phototransistor (light receiving means) oscz oscillation circuit (light emission energizing means) CRT: Display (notification means) CPU: Microcomputer (electronic control unit)-16
= RXI, RX2. RX3. RX4. RX5.
RX6: FM receiver (signal receiving means)

Claims (3)

[Claims] (1) A band-shaped support member; A light-emitting means attached to the support member with its optical axis directed inward; A light-emission energizing means for urging the light-emitting means; Put it on,
A plurality of light receiving means arranged with optical axes facing substantially the same direction as the light emitting means; Notifying means for displaying at least one of numerical value and sound output; and the number of fluctuations or fluctuations of the electrical signal from the light receiving means within a predetermined time. A heart rate measuring device comprising: an electronic control device that calculates a value according to a cycle and energizes the notification means according to the result. (2) The electronic control device comprises: a signal transmitting means for outputting a radio wave modulated by the electrical signal from the light receiving means; and a signal receiving means for receiving the radio wave and demodulating a heartbeat signal. The heart rate measuring device according to item 1). (3) The heartbeat measurement according to claim (1) or (2), wherein the light emitting means and the light receiving means are a plurality of sets arranged at positions apart from each other on the support member. Device.