JP4845303B2 - Pulse meter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pulsometer that measures the pulse of a human body during exercise in exercise equipment such as walking, running, and ergometer.
[0002]
[Prior art]
As a conventional pulsometer, there is, for example, Japanese Patent Laid-Open No. 8-66378 which applies a change in the transmittance of light penetrating the earlobe in a pulsometer used also in an ergometer for indoor motion. In addition, there are those that can measure the cardiac potential difference of the chest by pulse counting and can measure it while exercising, and those that need to be stationary but measure it by placing a finger on a pulse wave sensor attached to a wristwatch or the like.
[0003]
[Problems to be solved by the invention]
Those using light are not suitable for everyone because the color of the skin, such as race and individual differences, and the transmittance is extremely different and cannot be detected. The environment for outdoor use includes days when the temperature is high in summer and days when the temperature is low in winter. In principle, changes in blood volume in capillaries are detected by transmitted light, so the attachment site is easily affected by outside air. There is no problem on high days, but when the temperature is low, there is a problem that blood circulation is poor due to blood vessel contraction and detection is impossible, and the use outdoors is limited.
[0004]
Further, as a problem in outdoor use, since strong sunlight propagates through the body, signal detection is hindered by saturation of the light receiving amplifier, a decrease in the SN ratio, and the use environment is limited.
[0005]
In the case of using the electrocardiogram, the site where the most stable detection is possible is limited to the vicinity of the heart, but this causes a problem of causing discomfort because the chest is fastened together with the troublesomeness of wearing.
[0006]
Especially for women, many people feel resistance to wearing outdoors. When the electrocardiogram is detected at a part that is easy to wear, it is far from the heart and the signal becomes extremely weak and can be at rest, but it is very difficult to measure during exercise. Therefore, there was a problem that it could not be measured during exercise.
[0007]
As described above, the conventional pulse meter has many problems in practicality. Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide a pulse meter that takes into consideration the use of everyone, outdoor use, wearability, operability, and the like.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the pulse meter of the present invention includes a sensor unit configured by a transmission unit that generates ultrasonic waves and a reception unit that receives reflected ultrasonic waves, and a support unit that fixes them on the head artery. And an ultrasonic transmission / reception circuit, a circuit for processing a Doppler signal, a circuit for counting a pulse signal, and a display unit.
[0009]
This pulsometer pays attention to a change in blood flow flowing through an artery and applies a ultrasonic wave to the blood flow to detect a reflected Doppler signal to obtain a pulse signal. Ultrasound does not depend on the skin color and detects signals from blood flow through the arteries, so there is no need to worry about changes in the outside air. Does not weaken the signal to be detected.
[0010]
Further, according to claims 3 and 4, for example, a signal from a reflected wave synchronized with the signal of the acceleration sensor can be external noise. It is possible to obtain a more accurate pulse by thinning out the count circuit on the assumption that.
[0011]
According to the fifth aspect of the present invention, the optimum positions of the artery and the sensor unit can be determined by listening to sound.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments.
[0013]
FIG. 1 is a schematic perspective view showing Embodiment 1 of the present invention. In this spectacle-type pulsometer 10, a sensor section 12 having an acceleration sensor, a signal line 14, and a circuit box 13 incorporating a circuit for processing a Doppler signal are attached to a temple (support section) 11 of the spectacle-type frame. It was. The earphone 17 for listening to the Doppler sound is detachable from the circuit box 13. The circuit box 13 and the display unit 15 with the power switch 18 are connected by a cable 16.
[0014]
Each specific example will be described next. FIG. 2 shows a state in which a spectacle-type pulsometer is attached. The spectacle-type frame 11 uses a lightest object for sports and has a structure in which tension is applied to both sides of the head and the position does not shift during exercise. In addition to Doppler signals due to blood flow, Doppler signals due to body movement are mixed. In order to minimize the influence, the sensor unit 12 consisting of an acceleration sensor and ultrasonic wave transmission / reception is fixed to the vine part and is worn when worn. Can be closely attached to the superficial temporal artery in front of the eye.
[0015]
This part is an artery that has no body hair and is close to the surface of the body, so that it is easy to detect blood flow, and since high pressure is applied, there is very little fluctuation even during disturbance during exercise. Furthermore, since this part is the head, the impact is less than that of other parts, and since there is no joint part, it becomes a part where body movement noise is unlikely to occur. The ultrasonic wave output from the ultrasonic sensor is reflected by the flowing red blood cells to generate a Doppler signal, and its frequency shift Δf is given by Equation 1.
[0016]
Δf = (2vf / c) · cos θ (Formula 1)
Here, v: blood flow velocity (m / s), f: incident frequency (Hz), c: sound velocity (m / s), θ: angle formed between the ultrasonic wave and blood vessel.
Since v in Equation 1 is a relative speed with respect to the reflection target, the Doppler signal is also generated by the movement of the glasses-type frame. When the frame is moved by an impact, the amount appears as noise. Since this frame cannot be completely fixed to the living head, it is necessary to recognize an impact causing noise by an acceleration sensor. From the above, by having an acceleration sensor, it is possible to recognize that the signal contains noise and prevent a pulse count error.
[0017]
Therefore, the acceleration sensor was set so that the direction of sensitivity was the vertical direction of the body. This is because gravity always acts in the direction of the center of the earth, and the direction of the impact force that is applied to the head by a motion such as running is the largest with respect to the ground. Depending on the type of exercise, it may be necessary to increase to 2 or 3 axes.
[0018]
In order to handle the high frequency, the signal line 12 is wired so as to be as short as possible by using a shielded wire for transmission and reception. In order to make the circuit box 13 at the rear end of the vine small and light, surface mount components were used as electronic components. The circuit box 13 includes an oscillation circuit and a transmission unit driving circuit that generate and drive a predetermined frequency to the transmission unit of the sensor unit 12, and further amplifies and detects a signal from the reception unit, and shifts the frequency. It has a circuit for obtaining Δf and a pulse signal, and a circuit for amplifying the signal of the acceleration sensor.
[0019]
The frequency shift Δf is input to the earphone 17, and the pulse signal and the acceleration sensor signal are input to the display unit 15 via the cable 16. The earphone 17 can hear the frequency shift Δf as an audio band sound, and can confirm and adjust the position of the superficial temporal artery and the sensor portion, and the state of the pulse change in an analog manner without looking at the display. felt. It can be removed when not in use. Further, by incorporating the battery into the circuit box 13, it is possible to incorporate the battery into the glasses-type frame 11 and confirm the pulse pitch with sound.
[0020]
The cable 16 performs signal transmission and power supply from DC to about 5 Hz. Since it is easy to handle and can be lengthened, the display unit 15 can be attached to the wrist or clothes. The display unit 15 includes digital processing, display, and a battery. The entire power supply is turned on / off by the power switch 18. A pulse signal and an acceleration signal are converted into digital by an A / D converter, and a series of processing such as pulse wave peak detection, peak interval time measurement, erroneous count prevention, and display on an LCD is performed by a CPU.
[0021]
FIG. 3 is a schematic perspective view of the behind-the-ear pulse meter according to the second embodiment. This ear-mounted pulsometer 30 is basically the same in configuration as the eyeglass-type pulsometer 10 of FIG. 1, except that the wearing location is one ear. Regardless of whether the attachment means is the glasses-type frame 11 or the ear-hook type frame 32, the sensor unit must be brought into close contact with the superficial temporal artery. A sensor unit 33 having an acceleration sensor was attached to the tip of an ear-mounted frame 32 with a built-in signal line. A circuit box 31 incorporating a circuit for processing a Doppler signal, a display unit 15 incorporating a CPU, a battery, and a power switch 18 and using an LCD for display, a cable 16 for connecting them, and a detachable earphone 17 are configured. ing. Each specific example will be described next.
[0022]
FIG. 4 shows a state in which the ear-mounted pulsometer is mounted, and the ear-mounted frame 32 and the curved portion of the circuit box 31 can be stably mounted by putting them on the base of the ear. Furthermore, the two bodies are twisted together, and the sensor unit 33 is brought into close contact with the superficial temporal artery by stretching between the ear and the temporal region. Because it is made, it has springiness. There are ± 3 levels of twisting, and it can be set to match the shape of the individual ear. By reversing the twisting direction of the ear hook frame 32, it is possible to deal with both the left and right ears.
[0023]
FIG. 5 is a block diagram showing an example of the circuit of the pulse meter as described above.
[0024]
In this example, the sensor unit is a single module including the ultrasonic sensors 43 and 44 and the acceleration sensor 60. The circuit box 13 is mainly an analog signal system. The display unit 15 is summarized in relation to the digital signal system and the power source. The acceleration sensor 60 for recognizing the impact is an AC output and detects only the impact. The output is amplified by the amplifier circuit 61 and input to the comparator 62 of the display unit by the cable 16. The signal is converted into a pulse output by the comparator 62 and then input to the CPU. The transmitter circuit 40 uses a crystal resonator having a stable frequency, and the transmitter drive circuit 41 is required to have a circuit having sufficient drive capability so that the ultrasonic sensor (transmission) 43 can be continuously driven. The The reflected wave from the arterial blood flow is very small, and the first stage amplifier circuit 45 with good SN is required. The detection circuit 46 can obtain a frequency shift Δf and a pulse waveform. However, body motion noise during exercise is also received, so that the noise component generated at 200 Hz from the vicinity of the frequency band DC can be picked up using the filter circuit 47 to pick up the frequency shift Δf due to blood flow. A good result is obtained when a BPF of 500 Hz to 5000 Hz is inserted. The pulse waveform here is amplified by the amplification circuit 48 and reproduced by the earphone 17.
[0025]
Further, a pulse signal having a low frequency can be obtained by connecting an envelope of this signal with the detection circuit 49. The pulse signal is amplified by the amplification circuit 50 until it reaches a predetermined level. However, at this time, noise components due to impact are distributed over a wide band and cannot be separated. Details will be described with reference to a flowchart showing an example of the operation of the pulse meter in FIG. The data is input to the A / D converter 51 of the display unit 15 through the cable 16. As the A / D converter 51, an 8-bit converter was used. Although it is possible to support 4 bits, 8 bits were selected in consideration of the signal range and economy.
[0026]
The CPU 52 uses a small single chip type, and the processing performed here is to measure the interval time by detecting the pulse wave peak, to prevent erroneous counting by the acceleration sensor signal, and to display the pulse rate. In the display, data is written from the CPU 52 to the LCD driving circuit 53 and displayed on the LCD 54. A power supply circuit 56 that supplies power from the battery 57 with a mechanical power switch 56 stabilizes the voltage and supplies it to each circuit.
[0027]
FIG. 6 is a flowchart showing an example of the operation of the pulse meter with the above configuration. When the power is turned on, it is repeated until the peak detection 81 is made. At this time, a level is set so as not to detect a small noise so that a pulse wave signal can be detected reliably. After the peak is detected, the process proceeds to the step of the acceleration sensor output 82.
[0028]
If there is an acceleration sensor output, it is determined that the pulse wave is not present, and the process returns to the peak detection loop to prevent erroneous counting. The case where the peak is detected and there is no acceleration sensor output 82 is assumed to be pulse wave peak detection.
[0029]
In the pulse wave interval time measurement 83, the pulse wave peak detection time interval is measured and stored. Next, in order to accurately measure the interval time of the pulse wave, the time measurement is reset / started to start the time measurement. Calculation is performed based on the peak interval time stored earlier, and the pulse per minute is obtained. The result is displayed as a pulse. By repeating the above, it is possible to display continuously.
[0030]
FIG. 7 is a diagram illustrating prevention of erroneous counting using an acceleration sensor. When the pulse signal + noise is displayed as it is, if the pulse rate is displayed as it is, it is calculated at a time interval of Δt1 ′ before Δt1, and the pulse rate becomes larger than the true value. Further, it is not normal at Δt1 ″. The case where it becomes a numerical value occurs.
[0031]
Therefore, it is possible to know that there has been some movement by sensing the output of the acceleration sensor. When peak detection is performed at the same timing, it is determined as noise and Δt1 ′ is ignored, and Δt1 which is a true value is measured. Can be displayed correctly. Similarly, when measuring Δt2, Δt2 ′ and Δt2 ″ can be canceled using the output timing of the acceleration sensor. This will be described based on the form of the third embodiment.
[0032]
FIG. 8 is a schematic perspective view of the clip-type pulsometer according to the third embodiment. The clip-type pulsometer 112 has a mechanism in which the sensor unit 106 having an acceleration sensor and the circuit box 131 are attached to and detached from the temple 120 (support unit). The sensor unit 106 having an acceleration sensor is fixed to the temple 120 of the eyeglass-type frame via the clip-type bracket 101, and the circuit box 131 is fixed via the clip-type bracket large 141. A sensor unit 106 having an acceleration sensor is a clip-type metal fitting 101 and has a mechanism capable of adjusting the position with respect to the superficial temporal artery. A sensor unit 106 having an acceleration sensor and a circuit box 131 incorporating a circuit for processing a Doppler signal are connected by a signal line 100. The earphone 17 for listening to the Doppler sound and the display unit 15 with the power switch 18 are detachable from the circuit box 131. Each specific example will be described next.
[0033]
FIG. 9A shows a plan view and a cross-sectional view of the sensor unit. The clip-type metal fitting 101 can be inserted into the side surface of the sensor unit 106 having an acceleration sensor, and three fixing position adjustment openings 107 are provided, so that the sensor contact surface 108 on the artery can be adjusted. ing. FIG. 9B shows a plan view and a cross-sectional view of the clip type metal fitting A. FIG. The top view and sectional drawing of the clip type | mold metal fitting B are shown to (c). The clip-type metal fitting A101 and the clip-type metal fitting B104 are made of a spring material, stainless steel (or plastic), and the clip portion 103 and the clip portion 105 sandwich and fix the temple 120 of FIG. Three protrusions 102 are provided by pressing so that the fixing position can be adjusted, and the adjustment is made in three steps by fitting into the opening 107 of the sensor unit 106 having an acceleration sensor. Further, the clip-type metal fitting A101 and the clip-type metal fitting B104 are bent so that the position is not shifted during the exercise. Regarding the thickness of the vine 120, the size is changed between the clip portion A103 and the clip portion B105 for the thin one and the thick one. The cable outlet was placed in the center so that it could be attached to either the left or right vine.
[0034]
FIG. 10 shows a plan view and a cross-sectional view of the clip-type pulsometer attached to the vine (supporting portion). The clip-type metal fitting A101 is fixed following the surface of the temple 120. Since the clip-type metal fitting A101 is bent, tension is applied when the clip-type metal fitting A101 is attached, and the sensor contact surface 108 is fixed on the superficial temporal artery, and displacement and floating during movement prevent. The fixing position can be easily adjusted by inserting / removing the clip-type metal fitting A101 from / to the sensor unit 106 having the acceleration sensor.
[0035]
FIG. 11A shows a plan view and a cross-sectional view for explaining the circuit box structure. The circuit box 131 incorporating the circuit for processing the Doppler signal is provided with two openings for inserting the clip-type metal fittings 141 on the side surface, and two openings 132 are provided on each side so as to be attached to either the left or right vine. .
[0036]
FIG. 11B shows a plan view and a cross-sectional view of the clip-type metal fitting. The clip-type metal fitting 141 is made of a spring material, stainless steel (or plastic), and a slit is formed in the center of the clip portion 143 so that it can follow the bending of the vine.
[0037]
For fixing to the circuit box, the protrusion 142 formed by pressing and the opening 132 of the circuit box can be fixed and can be easily attached and detached. Regarding the thickness of the vine, the size of the clip portion 143 is changed between a thin one and a thick one.
[0038]
FIG. 12 shows a plan view of the circuit box attached to the temple 120.
[0039]
The clip-type metal fitting 141 is fixed following the surface of the vine 120. The clip portion of the clip-type metal fitting 141 has a slit in the center, so there are two fixing points, so that it can be fixed more securely. It has a structure that can withstand the impact of movement. The circuit box is located behind the ear and is fixed above the vine.
[0040]
【The invention's effect】
Since the pulse meter of the present invention is configured as described above, it has the following effects.
[0041]
(1) According to the first aspect, since the sensor unit, the support unit for fixing them on the head artery, the ultrasonic transmission / reception circuit, and the circuit for processing the Doppler signal are integrated in the head, body motion noise It is strong and easy to install. In addition, both hands are free and can be used for exercises that use hands.
[0042]
(2) According to the second aspect, the pulse can be reliably captured by fixing the sensor unit on the superficial temporal artery in front of the ear.
[0043]
(3) According to claim 3, by having an acceleration sensor for detecting the movement of the mounting portion, it is possible to sense that an excessive impact has been applied and to grasp the state.
[0044]
(4) According to the fourth aspect, an accurate pulse rate can be displayed by determining a signal synchronized with the signal of the acceleration sensor as noise and thinning it out from the count circuit.
[0045]
(5) According to the fifth aspect, the sensor unit and the circuit box can be attached to and detached from the support part, and can be attached to support parts of other sizes, so that it can be used in a general-purpose eyeglass frame.
[0046]
(6) According to the sixth aspect, it is possible to cope with various head sizes by having a mechanism for aligning the position of the sensor unit on the head artery.
[0047]
(7) According to the seventh aspect, since the optimum position of the sensor portion with respect to the artery can be confirmed by sound, anyone can easily search for the artery and obtain the maximum sensitivity.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a glasses-type pulsometer according to Embodiment 1. FIG.
FIG. 2 is a diagram showing a state in which a spectacle-type pulsometer is worn.
FIG. 3 is a schematic perspective view of an ear-mounted pulse meter according to a second embodiment.
FIG. 4 is a diagram showing a state in which an ear-mounted pulse meter is worn.
FIG. 5 is a block diagram showing an example of a circuit of a pulse meter.
FIG. 6 is a flowchart showing an example of the operation of the pulse meter.
FIG. 7 is a diagram illustrating prevention of erroneous counting using an acceleration sensor.
8 is a schematic perspective view of a clip-type pulsometer of Example 3. FIG.
FIG. 9A is a plan view and a cross-sectional view of the sensor unit.
The top view and sectional drawing of the clip type metal fitting A are shown in (b).
The top view and sectional drawing of the clip type | mold metal fitting B are shown to (c).
FIG. 10 shows a plan view and a cross-sectional view of a clip-type pulsometer attached to a vine (support part).
FIGS. 11A and 11B are a plan view and a cross-sectional view illustrating a circuit box structure.
(B) shows a plan view and a sectional view of a clip-type metal fitting.
FIG. 12 shows a plan view of the circuit box attached to the hanging (supporting) 120. FIG.
[Explanation of symbols]
10 glasses-type pulse meter 11 vine (support)
12 Sensor part 13 Circuit box (circuit)
15 Display unit 30 Ear-mounted pulse meter 32 Ear-mounted frame (support unit)
33 Sensor unit 31 Circuit box (circuit)
112 Clip Type Pulse Meter 106 Sensor Unit 131 Circuit Box 101 Clip Type Metal A
141 Clip type metal fittings

Claims (4)

A transmitter for transmitting an ultrasonic wave for applying a superficial temporal artery Doppler signals change in frequency in response to the blood flow changes in the superficial temporal artery by the ultrasonic waves are reflected on the superficial temporal artery An ultrasonic sensor unit including a receiving unit for receiving;
A behind-the-ear support portion for fixing the ultrasonic sensor portion to the superficial temporal on arteries,
A circuit unit having a drive circuit for driving the transmission unit, and a reception circuit for obtaining a pulse signal by processing the Doppler signal;
A pulse calculation means for obtaining a pulse based on the pulse signal,
The pulse meter according to claim 1, wherein the circuit unit sets a position of the ultrasonic sensor unit with respect to the superficial temporal artery by outputting a sound according to the changed frequency. The pulsometer according to claim 1, wherein the ultrasonic sensor unit includes an acceleration sensor that detects a noise signal mixed into the pulse signal due to body movement.   The pulse meter according to claim 2, wherein the pulse calculation means thins out a signal synchronized with the noise signal from the pulse signal. The behind-the-ear support portion, pulse rate monitor according to claim 1, further comprising a position adjustment member for adjusting the position of the ultrasonic sensor unit with respect to the superficial temporal artery.

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