JP2000308639A - Pulse wave detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse wave detection device capable of detecting pulse wave with a small power consumption, and extending the service time. SOLUTION: An ultrasonic wave f0 of 10 MHz in frequency is transmitted from an ultrasonic transmitting means 11 to an artery 2, and the frequency- modulated reflecting wave f1 is received by an ultrasonic wave receiving means 21. This reflecting wave f1 is subjected to the FM detection, and the pulse rate is displayed. The ultrasonic wave is transmitted for 10 seconds by the intermittent drive of an intermittent operation control means 12 to measure the pulse rate, and then, stopped for 50 seconds. The display of the pulse rate while stopping the measurement is replaced by the measurement immediately before the measurement is stopped. By intermittently driving the ultrasonic wave transmitting means 11, the power consumption is reduced, and the means can be mounted even on a portable device compact and small in battery capacity such as a watch, and can be used for a long time. When a bodily motion is detected by a bodily motion detection part 13 and a pulse rate fluctuation judgment part 14, the transmission of the ultrasonic wave for 10 seconds is re-started.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse wave detecting device, and more particularly, to a pulse wave detecting device for detecting a pulse wave by transmitting and receiving an ultrasonic wave to and from an artery.

[0002]

2. Description of the Related Art Detecting a pulse wave due to a blood flow flowing through an artery is widely used in medical practice and health care. This pulse wave detection is widely performed not only when the pulse rate is detected as a pulse rate for a predetermined time by palpation, but also when the pulse rate is automatically detected electronically using a pulse wave detection device. As a device for electronically detecting a pulse wave and obtaining a pulse rate, a piezo-type piezoelectric element is arranged on an artery as a sensor, and a pulse is detected from a pressure change of the epidermis (a displacement of the epidermis due to pressure) due to a pressure change inside the artery. There are those that detect the pulse rate and those that detect the pulse rate using ultrasonic waves. As a pulse wave detecting device using an ultrasonic wave, there is a device using a Doppler effect due to a blood flow, and it is proposed in, for example, JP-A-1-214335 and US Pat. No. 4,086,916.

FIG. 6 shows how the frequency of an ultrasonic wave changes due to such a Doppler effect. Now, when an ultrasonic wave having a frequency f0 as shown in FIG. 6A is transmitted from the body surface toward the artery, the transmitted ultrasonic wave is reflected by blood flowing through the artery. When this reflected wave is received by the receiving element, a change in the frequency of the reflected wave can be detected. That is, assuming that the frequency of the received wave is f1, FIG.
As shown in (b), during the systole of the heart, the speed of the blood flow flowing through the artery is high, so that the frequency of the reflected wave increases due to the Doppler effect (part A), and conversely, the blood during the relaxation of the heart. Since the flow velocity is low, the frequency is lower than that of the part A (part B). In this way, the ultrasonic wave is applied to the blood flow in the artery whose flow velocity changes according to the heartbeat, and the pulse wave is detected by detecting the change in the frequency, and further, the pulse rate is detected,
For example, the blood flow velocity can be detected.

[0004]

As described above, in a pulse wave detecting apparatus for detecting a pulse wave using the ultrasonic Doppler effect,
Since ultrasonic waves are used, there is a problem that power consumption is very large. Therefore, the conventional pulse wave detection device must be used in an environment such as a hospital or home where power can be sufficiently supplied, or when used in an environment other than such an environment, the pulse wave is detected only for a short period of time. There was a problem that can not be measured. Particularly, in the case of a pulse wave detection device having a portable size and weight, such as a pulse wave detection device incorporated in a wristwatch, the use time is further shortened because the capacity of the battery is limited. There is.

Accordingly, the present invention has been made to solve the problem in such a conventional pulse wave detecting device.
It is an object of the present invention to provide a pulse wave detecting device that can detect a pulse wave with low power consumption and can extend a use time.

[0006]

According to the pulse wave detecting device of the present invention, a transmitting means for transmitting an ultrasonic wave toward an artery and an ultrasonic wave transmitted from the transmitting means and reflected by blood flowing through the artery are received. Receiving means, and an intermittent operation control means for intermittently driving the transmitting means so as to repeat a drive for transmitting ultrasonic waves for a time T of at least two pulses and a drive stop for stopping transmission of ultrasonic waves, The apparatus includes pulse wave information acquiring means for acquiring pulse wave information on a pulse wave from the ultrasonic wave received by the receiving means, and output means for outputting the pulse wave information acquired by the pulse wave information acquiring means. And
The pulse wave information acquisition unit has a frequency detection unit that detects a frequency change of the ultrasonic wave received by the reception unit or an amplitude detection unit that detects an amplitude change, and a detection signal obtained by the frequency detection unit or the amplitude detection unit. To obtain pulse wave information. The apparatus further includes a body movement detecting unit that detects a body movement and outputs a reset signal, and the intermittent operation control unit restarts driving at the time T when the reset signal is output.

Thus, according to the present invention, for example, the pulse 2
By transmitting an ultrasonic wave only for 10 seconds as a time T equal to or more than a beat, and then stopping the transmission of the ultrasonic wave for, for example, 50 seconds,
By alternately performing the measurement of the pulse wave and the suspension of the measurement, the power consumption can be reduced to 1/6. In the present invention, the pulse wave information at the time of non-measurement can be replaced with the pulse wave information at the time of measurement. For example, if the pulse rate measured during 10 seconds is N, the pulse rate during the non-measurement time of 50 seconds is also N, and the pulse rate N is displayed for 1 minute. On the other hand, since the pulse rate during non-measurement does not indicate an actually measured value, if exercise is started during non-measurement, a large error may occur between the actual pulse rate and the displayed pulse rate. On the other hand, in the present invention, a change in the pulse rate is predicted by the body motion detecting means, a reset signal is output, and the pulse wave measurement (transmission of ultrasonic waves) for 10 seconds (time T) is restarted. This makes it possible to measure the pulse wave at the start of the operation, so that an error in the displayed pulse rate can be reduced.

In the pulse wave detection device according to the present invention, the pulse wave information obtaining means includes a storage means for storing the pulse wave information, and the output means outputs the pulse wave information stored in the storage means. You may make it. That is, pulse information and detection information for a predetermined time are stored in the storage means,
For example, by outputting to an external device such as a medical diagnosis device, it can be used for comprehensive medical diagnosis. When the pulse wave information is used for medical diagnosis or the like, it is desirable to shorten the drive stop time of the transmitting means, for example, drive for 10 seconds and stop driving for 10 seconds. For this purpose, the drive time T and the drive stop time may be adjusted by the user to an arbitrary time, and a plurality of modes (daily life mode, Exercise mode, medical measurement mode, etc.) may be set in advance, and the user may select one of the modes.

Further, in the pulse wave detecting device of the present invention, the pulse wave information acquiring means acquires a pulse rate from the detected signal as pulse wave information, and the output means acquires the pulse rate by the pulse wave information acquiring means. The pulse rate may be output. Thereby, the most common pulse can be confirmed on a daily basis. Further, the pulse wave detection device of the present invention further includes a display unit, wherein the pulse wave information obtaining unit obtains a pulse rate or a pulse wave waveform as information on a pulse wave from the detection signal, and the output unit outputs the pulse wave. The pulse rate or the pulse waveform acquired by the wave information acquiring means may be output to the display means. Accordingly, by displaying the pulse rate or the pulse wave waveform, the pulse rate and the pulse wave waveform can be easily confirmed even in daily life. In the pulse wave detection device of the present invention, the receiving system may be intermittently driven in synchronization with the intermittent driving of the transmitting system.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the pulse wave detecting device according to the present invention will be described below in detail with reference to FIGS. (1) Overview of the present embodiment In the pulse wave detecting device of the present embodiment, an ultrasonic wave f0 having a frequency of 10 MHz is transmitted from the ultrasonic wave transmitting means 11 toward the artery 2 from the body surface (transmitting means), and a reflection target ( Measurement object)
Reflected wave f frequency-modulated by the Doppler effect of the blood flow
1 is received by the ultrasonic receiving means 21 (receiving means). A pulse wave is extracted by performing FM detection (frequency detection) on the received reflected wave f1, and a pulse is counted (pulse wave information obtaining means) to display a pulse wave waveform and a pulse rate (output means). Then, the intermittent operation control means 12 controls the ultrasonic transmission means 11.
, The ultrasonic wave is transmitted for 10 seconds to measure the pulse wave (pulse rate), and then the measurement is stopped for 50 seconds.
As for the display during the actual measurement stop of the pulse wave waveform and the pulse rate, the values at the actual measurement immediately before the measurement is stopped are displayed instead. By intermittently driving the ultrasonic wave transmitting means 11 in this manner, power consumption can be reduced, and even a small portable device such as a timepiece having a small battery capacity can be attached. Time use becomes possible. Further, the body movement is detected by the body movement detecting section 13 and the pulse rate fluctuation determining section 14 and a reset signal is output (body movement detecting means).
With the reset signal as a trigger, the intermittent operation control means performs the drive control for 10 seconds from the beginning regardless of the current intermittent drive state. Thus, the possibility of a change in the pulse wave waveform or pulse is predicted, and the measurement is immediately restarted, so that the error in the pulse rate when the actual measurement is stopped can be reduced.

(2) Details of the present embodiment FIG. 1 shows the configuration of the pulse wave detecting device according to the first embodiment. As shown in FIG. 1, the pulse wave detecting device includes an ultrasonic wave transmitting unit 11, an intermittent operation control unit 12, and a body motion detecting unit 1 as an ultrasonic wave transmitting system for transmitting an ultrasonic wave.
3 and a pulse rate fluctuation determination unit 14. The pulse wave detection device includes an ultrasonic wave receiving unit 21 and a detection circuit 22 as an ultrasonic wave receiving system that receives the ultrasonic waves (reflected waves) reflected by the blood flowing through the artery 2 and processes the pulse waves. , Amplifying circuit 23, waveform shaping circuit 24, pulse rate calculating circuit 30
And a display device 40.

Ultrasonic transmission means 1 in an ultrasonic transmission system
Numeral 1 includes an oscillator composed of a piezoelectric element, and emits an ultrasonic wave having an output power corresponding to a voltage applied to the oscillator. The ultrasonic transmitting means 11 transmits an ultrasonic wave of 10 MHz from the body surface toward the artery 2. The intermittent operation control means 12 includes the ultrasonic transmission means 1
1 is intermittently driven, and the driving time T1
During the period, the ultrasonic transmitting means 11 is driven to transmit ultrasonic waves,
Thereafter, the transmission of the ultrasonic waves is stopped repeatedly for the drive stop time T2. Intermittent operation control means 12
Includes an oscillation circuit that oscillates an ultrasonic wave of 10 MHz, and an intermittent drive signal generation unit that generates an intermittent drive signal that repeats ON for T1 time and OFF for T2 time for performing intermittent drive. In this embodiment, the intermittent operation control means 12
Is set so that the driving time T1 = 10 seconds and the driving stop time T2 = 50 seconds, and the pulse wave is measured only for 10 seconds in one minute.

FIG. 2 shows waveforms in the intermittent operation control means 12 and the ultrasonic wave transmitting means 11. FIG.
(A) shows a 10 MHz ultrasonic oscillation signal f0 that can be generated by the oscillation circuit of the intermittent operation control means 12, and shows a waveform in the case of continuous oscillation. FIG.
(B) shows the intermittent drive signal F0 generated by the intermittent operation control means 12, and repeatedly outputs ON (high state) for time T1 = 10 seconds and OFF (low state) for time T2 = 50 seconds. You. The intermittent operation control means 12 intermittently generates the ultrasonic oscillation signal f0 shown in FIG. 2A by the intermittent drive signal F0 shown in FIG. 2B as shown in FIG. By amplifying f0 to output power and supplying the amplified power to the ultrasonic transmission unit 11, the ultrasonic transmission unit 11 transmits an ultrasonic wave having a waveform similar to that of FIG.

The on-time T1 and the off-time T2 of the intermittent drive signal are not limited to T1 = 10 seconds and T2 = 50 seconds, but may be other times if T1 is a time equal to or more than two pulses. it can. That is, the minimum pulse rate N is set to 30 times / minute, and T may be 4 seconds or more, and may be 5 seconds, 15 seconds, or the like. On the other hand, the time T2 is not particularly limited, but since the measured value immediately before the measurement is stopped is substituted for the pulse rate during the non-measurement time, the error of the substitute value may increase. Is not preferred. On the other hand, if it is too short, the effect of low power consumption cannot be sufficiently obtained. Therefore, as T2, in addition to 50 seconds, 1
0 seconds, 20 seconds, 30 seconds, 40 seconds, 1 minute, 2 minutes, 3 minutes, 5
Minutes are selected. As for the combinations of T1 and T2, all the combinations exemplified above can be adopted.

The body movement detecting section 13 comprises at least one of an acceleration sensor, a piezoelectric element, a tilt switch and the like, and detects body movement. In the present embodiment, the body motion detection unit 13 is arranged near the intermittent drive unit or the like, but it is arranged near the ultrasonic wave transmission unit 11 or near the heart, near the waist, or on the foot. It may be. The pulse variation determination unit 14
When the body motion is detected by the body motion detection unit 13, the pulse wave waveform and the possibility of a pulse change are predicted, and a pulse signal is supplied to the intermittent operation control unit 12 as a reset signal. The body movement detecting section 13 and the pulse rate fluctuation determining section 14 function as body movement detecting means.

When the reset signal is supplied, the intermittent operation control means 12 drives the drive (ultrasonic wave) for T1 seconds from the supply of the reset signal regardless of the current state of the intermittent drive (during the stop of the drive or during the drive). Oscillation control) is restarted. FIG.
Represents the state of the intermittent drive of the ultrasonic wave transmitting means 11 by the intermittent operation control means 12. As shown in FIG. 3A, when a switch for starting the measurement is turned on at time t1 and a start signal S is supplied to the intermittent operation control means 12 from a start circuit (not shown), the intermittent operation control means 12 (C) As shown in FIG.
Is transmitted from the ultrasonic transmission means 11 for a time T1, then the transmission is stopped for a time T2, and thereafter the intermittent driving is similarly continued. Then, as shown in (b), at time t2, when the body movement is detected by the body movement detection unit 13 and the reset signal R is supplied from the pulse rate fluctuation determination unit 14 to the intermittent operation control unit 12, the intermittent operation control is performed. In the means 12, the ultrasonic wave is transmitted again for the time T1 from the reset signal R. In the example shown in FIG. 3, since the body motion is detected during the stop of the driving of the ultrasonic wave transmission and the reset signal R is supplied to the intermittent operation control means 12, even during the stop of the driving, the time T <b> 1 Ultrasound transmission is resumed. Also, when the reset signal R is supplied to the intermittent operation control means 12 during driving (during transmission of ultrasonic waves), transmission of ultrasonic waves at the time T1 is similarly restarted from the reset signal R. In this case, the time T1 ′ (2T1 ≧ T1 ′> T) combined with the measurement before the reset signal R is supplied.
Ultrasonic waves are transmitted during 1).

10M transmitted from the ultrasonic transmitting means 11
The ultrasonic wave of Hz is reflected by the blood flowing through the artery 2 and received by the ultrasonic wave receiving means 21. This reflected wave is frequency-modulated by the Doppler effect of the blood flow velocity, and a pulse wave can be detected from a change in the frequency. That is, the blood flow velocity of the blood flowing through the artery 2 changes depending on the systole (pulse) and the diastole of the heart. Therefore, the frequency of the transmitted ultrasonic wave changes due to the Doppler effect when reflected by the blood flow. When the frequency f1 of the reflected wave in this case is f0 of the ultrasonic wave, v is the blood flow velocity, c is the sound velocity in the body, and θ is the incident angle of the ultrasonic wave with respect to the blood flow velocity, the following expression (1) ). f1 = f0 (1 + 2v × cos θ / c) (1) Then, the frequency of the ultrasonic wave is changed from f0 to f1 by reflection.
And the deviation df is given by the following equation (2). df = f1−f0 = f0 × 2v × cos θ / c (2) Therefore, for example, each value is c = 155 m / s and v = 0.3
Assuming that m / s and f0 = 9.5, the frequency deviation df is 3.
8 KHz. In the equation (2), since the blood flow velocity v varies depending on the pulse, the frequency deviation df varies in a range from about 2 KHz to 4 HHz.

In this embodiment, a pulse wave is detected by detecting the change in the frequency deviation df by a demodulation method of a frequency modulation wave. That is, the reflected wave f1 received by the receiving means 21 in FIG. 1 is supplied to the detection circuit. In the detection circuit 22, a change df in the reception frequency that changes due to the pulse is extracted as a change in voltage and supplied to the amplifier circuit 23. The amplifying circuit 23 amplifies a change in the supplied voltage and supplies the amplified voltage to the waveform shaping circuit 24. The waveform shaping circuit 24 shapes the amplified voltage waveform that changes according to the pulse into a pulse wave and supplies the pulse wave to the pulse rate calculation circuit 30.

The pulse rate calculation circuit 30 generates a pulse wave when the comparison value exceeds the comparison value, for example, and sets the time interval of the pulse wave to a predetermined number of times (for example, once, two times).
3 times, 5 times, 7 times, 8 times, etc.), and the pulse rate N for one minute is obtained from the average time Ta of each measurement time according to the following equation (3). N = 60 / Ta (3) The present invention is not limited to the case where the pulse rate is obtained from the average time Ta between pulses. For example, the drive time T1 (in the present embodiment, 1
The pulse number w occurring within 0 second) may be detected, and the pulse rate N for one minute may be obtained by the following equation (4). N = w × (60 / T1) (2) The pulse rate calculation circuit 30 supplies the obtained pulse rate N and a pulse signal generated corresponding to each pulse to the display device 40.

The display device 40 digitally displays the supplied pulse rate N on a liquid crystal display screen, and displays a blinking green color in response to the supplied pulse signal to indicate the presence of a pulse. The user can visually recognize his or her pulse wave by seeing this green blinking. Note that a pulse sound may be output according to the supplied pulse signal so that the presence of a pulse can be recognized by hearing.

FIG. 4 shows a state in which a pulse wave is detected by incorporating such a pulse wave detecting device into a timepiece. As shown in FIG. 4, the pulse wave detector (clock) 60
A watch body 61 and a belt 62 are provided.
The sensor 19 is attached inside the. Clock 60
As in a general watch, the watch body 61 is attached to the left (or right) wrist 2a with the watch main body 61 facing the back of the hand. At this time, as shown in FIG. 4B, the position of the sensor 19 can be adjusted by moving the sensor 19 in the longitudinal direction of the belt 62 so as to be located on the radial artery. As shown in FIG. 4 (c), the sensor 19 includes an ultrasonic transmitting unit 11 and an ultrasonic receiving unit 21.
The belt 62 is arranged along the radial artery 2 in a direction orthogonal to the length direction of the belt 62, and the ultrasonic transmitter 11 is disposed on the hand side and the ultrasonic receiver 21 is disposed on the shoulder side. The positions of the ultrasonic wave transmitting means 11 and the ultrasonic wave receiving means 21 may be reversed.

The watch main body 61 includes a drive unit such as a watch movement, an intermittent operation control unit 12, an output power control unit 13, a pulse rate fluctuation determination unit 14, a detection circuit 22, an amplification circuit 23, and a waveform shaping circuit 24. , A pulse rate calculation circuit 30, and a display device 40. Intermittent operation control means 1
The oscillation circuit in 2 may be used also as the oscillation circuit of the drive circuit used for the clock function. A sensor 19, an intermittent operation control means 12 disposed on a timepiece main body 61, a detection circuit 2
2 is connected by a wiring (not shown) incorporated in the belt 62. The display surface (dial) of the clock main body 61 includes a clock display unit 63 that displays time, date, day of the week, and the like as a clock, and a display device 41. The display device 41 includes a pulse rate display unit 64 on which the pulse rate N is displayed.
And a pulse display section 65 which blinks green in accordance with each pulse. The blinking color of the pulse display section 65 may be changed according to the pulse rate. For example, 69 or less flashes yellow, blue flashes when the pulse rate is 70 to 90, 91 to 110
Blinks green between, blinks orange between 111-130, 13
One or more flashes red. As described above, the blinking color of the pulse display section 65 changes according to the pulse rate, so that the current pulse state can be easily distinguished.

According to the above-described embodiment, the intermittent operation signal means 12 alternately performs the driving for transmitting the ultrasonic wave for the time T1 during which the pulse can be detected and the driving stop for stopping the transmission. Since the sound wave transmitting means 11 is intermittently driven, a pulse wave detecting device with low power consumption can be provided.
Therefore, it can be used for a long time even when attached to a small portable device such as a watch having a relatively small power supply capacity. Further, since the possibility of a change in the pulse rate is predicted from the body movement and the intermittent operation control means 12 drives the ultrasonic transmission means 11 for the time T1 from the beginning, the time T2 which is not measured can be calculated. It can be set relatively long, and the power consumption can be further reduced.

Next, a second embodiment of the present invention will be described. In the first embodiment, by setting the frequency of the ultrasonic wave transmitted from the ultrasonic wave transmitting means 11 to 10 MHz, the frequency of the reflected wave that changes in accordance with the blood flow velocity changes, and the pulse change from the frequency change is performed. It is designed to detect waves. On the other hand, in the second embodiment, a pulse wave is obtained by using the attenuation of the ultrasonic wave due to the blood flow rate flowing through the artery.

First, the principle and outline of pulse wave detection according to the present embodiment will be described with reference to FIG. In the artery, when the blood flow changes due to the pulse wave, the transfer coefficient when the ultrasonic wave propagates changes. It is considered that this is because the blood flow and blood density of the artery change due to the pulse wave, and the attenuation rate of the ultrasonic wave changes. In the present embodiment, based on the above principle, the ultrasonic wave transmitting means 11
The ultrasonic wave shown in FIG. The frequency f3 of the ultrasonic wave in this case is smaller than the frequency f0 = 10 MHz of the ultrasonic wave for frequency modulation by blood flow.
By setting the frequency to 32 KHz, the light is reflected while propagating in the artery 2 and transmitted to the ultrasonic receiving means 21. This ultrasonic wave is propagated while being attenuated by the pulsating flow in the artery 2, and FIG.
As shown in FIG. 5 (c), the ultrasonic wave (propagating wave) attenuated (arrow G portion) corresponding to the pulse is received by the ultrasonic wave receiving means 21 and the received ultrasonic wave is subjected to amplitude detection to obtain the waveform shown in FIG. The obtained pulse wave waveform (pulse wave information) H is obtained.

In the present embodiment, the pulse wave is detected by detecting a change in the attenuation of the ultrasonic wave transmitted from the ultrasonic wave transmitting means 11 based on such a principle. Then, the intermittent operation control means 12 transmits the ultrasonic wave F3 of 32 KHz for the time T1 similarly to the first embodiment, and thereafter stops transmitting the ultrasonic wave for the time T2.
Is operated intermittently. Since the frequency change due to the Doppler effect is a small value of 2 to 4 KHz (range of several%) with respect to the transmission frequency of 10 MHz, the change amount of the attenuation rate is 10% or more of the output power. In the embodiment, it is possible to more accurately detect a change in the attenuation rate due to the pulse wave.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the configuration of the embodiment, and other embodiments may be adopted and modified within the scope of the present invention. Is possible. For example, in the above-described embodiment, the pulse rate calculation circuit 30 may be configured by a pulse calculation control unit that performs digital signal processing and storage processing. In this case, the pulse wave output from the waveform shaping circuit 24 is supplied to the pulse calculation control unit, and the voltage waveform amplified by the amplification circuit 23 is digitally converted and supplied to the pulse calculation control unit. In addition to the display device 40, various external devices such as a personal computer and a medical diagnostic device can be connected to the pulse calculation control unit.

The pulse calculation control unit in this case mainly includes
CPU (Central Processing Unit), ROM (Read Only)
A microcomputer system provided with a memory), a RAM (random access memory), and a clock unit.
The pulse calculation control unit includes a DRAM, an SRAM, an EEP
Various storage media for storing data magnetically, electrically, and optically, such as a ROM and a hard disk, are provided. The storage capacity is arbitrary, but at least for one hour to one day.
Preferably, a storage capacity capable of storing pulse wave information for one week (more preferably, one month) (time change of pulse rate, pulse waveform from the amplifier circuit 23, etc.) is adopted. As described above, by storing the pulse wave information (pulse waveform) for a predetermined period in the storage medium, an external device is connected to the pulse wave detection device at a later date, and the stored pulse wave information is output, and the medical diagnosis is performed. Etc. can be used. However, when pulse wave information is used for medical treatment, the drive stop time T2 is set to increase the actual measurement time.
Should not be set too long. In this way, in the medical diagnostic device (external device), pulse wave information for a long time can be obtained, and the state of the user in daily life can be more accurately diagnosed from a medical viewpoint. For example, by examining the pulse fluctuation, it is possible to examine whether the user is in a state of psychological tension or in a relaxed state. It is also possible to check the rhythm of the pulse wave, the magnitude of the pulse, the rising speed of the pulse (fast or slow), and the like.

[0029]

According to the pulse wave detecting device of the present invention, the driving for transmitting the ultrasonic wave for at least the time T of two or more pulses and the driving stop for stopping the transmission of the ultrasonic wave are performed by the intermittent operation control means. As described above, since the transmitting means is intermittently driven, the pulse wave can be detected with low power consumption, and the use time can be extended.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a pulse wave detection device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing waveforms in an intermittent operation control unit and an ultrasonic transmission unit of the pulse wave detection device.

FIG. 3 is an explanatory diagram showing an operation state of intermittent driving by an intermittent operation control unit of the pulse wave detection device.

FIG. 4 is an explanatory diagram showing a state in which a pulse wave is detected by a pulse wave detection device incorporated in a watch.

FIG. 5 is a diagram illustrating the principle and outline of pulse wave detection according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a state of a frequency change of an ultrasonic wave due to the Doppler effect.

[Explanation of symbols]

 Reference Signs List 2 artery 11 ultrasonic transmitting means 12 intermittent operation controlling means 13 body motion detecting section 14 pulse rate fluctuation determining section 21 ultrasonic receiving means 22 detecting circuit 23 amplifying circuit 24 waveform shaping circuit 30 pulse rate calculating circuit 40 display device 60 clock 61 clock Main unit 62 Belt 63 Clock display 64 Pulse rate display 65 Pulse display

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Keisuke Tsubata 1-8-8 Nakase, Mihama-ku, Chiba-shi Inside Seiko Instruments Inc. (72) Inventor Chiaki Nakamura 1-8-1, Nakase, Mihama-ku, Chiba-shi, Chiba Inside Koinstruments Co., Ltd. (72) Inventor Masataka Shinogi 1-8-1, Nakase, Mihama-ku, Chiba-shi F-term (reference) in Koinstruments Inc. 4C017 AA10 AB02 AC23 BB02 BC06 FF19 4C301 DD03 DD10 EE18 HH52 KK27

Claims (3)

[Claims] A transmitting means for transmitting an ultrasonic wave toward an artery; a receiving means for receiving an ultrasonic wave transmitted from the transmitting means and reflected by blood flowing through the artery; Intermittent operation control means for intermittently driving the transmitting means, so as to repeat the driving for transmitting the ultrasonic wave and the driving stop for stopping the transmission of the ultrasonic wave, and the pulse wave from the ultrasonic wave received by the receiving means. A pulse wave detection device comprising: pulse wave information acquisition means for acquiring pulse wave information; and output means for outputting pulse wave information acquired by the pulse wave information acquisition means. 2. The apparatus according to claim 1, wherein said pulse wave information acquiring means has a frequency detecting means for detecting a frequency change of the ultrasonic wave received by said receiving means or an amplitude detecting means for detecting an amplitude change. The pulse wave detection device according to claim 1, wherein pulse wave information is obtained from a detection signal by the detection unit. 3. An intermittent operation control means for detecting a body movement and outputting a reset signal, wherein the intermittent operation control means restarts the driving at the time T when the reset signal is output. The pulse wave detecting device according to claim 1, wherein