JP2006296700A - Pulse rate measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulse rate measuring instrument capable of measuring a subject under exercise with the instrument installed around a wrist and allowing a long-time measurement without tightening the wrist. <P>SOLUTION: This pulse rate measuring instrument which detects the pulse of a subject to measure the pulse rate measures the pulse rate of the subject by disposing a thin type pressure sensor detecting the pulse, a computing means computing the pulse rate, and a display means displaying the pulse rate around one wrist of the subject with a band, and by allowing the thin type pressure sensor to detect the pulse. This constitution allows the measurement of the subject not only under a rest but also under the exercise with the instrument installed around the wrist alone and allows the long-time measurement without tightening the wrist. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pulse rate measuring apparatus that measures the pulse rate of a subject, and relates to a technique capable of measuring the pulse rate even when the subject is in a non-resting state using a thin pressure sensor.

  In recent years, an increase in lifestyle-related diseases such as hypertension, diabetes, heart disease, hyperlipidemia, and stroke has become a major social problem, although it is highly effective as a preventive and coping therapy for such lifestyle-related diseases. One example is exercise therapy. Exercise therapy includes a wide range of exercises such as walking and jogging that can be done easily from training in a gym. For example, walking is more effective by using a pedometer or exercise calorie meter as a measure of exercise amount. I can do things. Recently, a method of estimating the degree of burden on an exerciser's heart by measuring the pulse rate during exercise in real time is also considered effective.

  In general, an optical method is often used as a method for measuring the pulse rate. Specifically, for example, a pulse wave sensor including a light emitting element such as an LED and a light receiving element such as a phototransistor is disposed on the ear or fingertip, and infrared or near-infrared region light is emitted from the light emitting element. The reflected light or transmitted light is detected by the light receiving element. At this time, since the reflected light or transmitted light detected by the light receiving element includes pulse wave information, the pulse rate can be measured using this.

  However, in the above-described method, there is a problem that the signal is weak because the capillary is referred to, and accurate measurement is difficult because it is easily affected by noise. Therefore, for example, in Patent Document 1, a large signal can be obtained by arranging the above-described optical pulse wave sensor at a site where a signal from the artery of the wrist can be detected, and a plurality of light receiving elements must be used. Thus, the pulse wave can be detected even when the sensor mounting position is slightly deviated.

  Also, in Patent Document 2, a photoelectric pulse wave sensor is arranged at the base of the finger and wired with a wristwatch-type calculation display unit, so that the position of the pulse wave sensor is different from the wrist, even during exercise. The pulse rate can be measured without shifting. In this method, a signal from a pulse wave sensor is input to a wristwatch type calculation display unit to perform calculation and display. As another method, there is a method in which a pulse wave sensor is attached with a belt near the heart where the largest signal can be obtained, and data is transmitted wirelessly to a display device attached to the wrist. In this method, since a sensor is arranged near the heart, it is difficult to be affected by noise during intense exercise, and the pulse rate can be measured.

JP 2002-360530 A (FIG. 1) International Publication WO98 / 10699 pamphlet (Figure 1)

However, the above method has the following problems. In the method in which an optical pulse wave sensor is arranged at a site where a signal from the artery of the wrist can be detected and the pulse wave is detected from the obtained signal, the optical pulse wave sensor is detected from a position where the signal from the artery can be detected. If it is shifted, measurement cannot be performed. For example, it can be easily considered that the position is greatly shifted during exercise. In addition, when it is attached tightly to the wrist so as not to cause a large shift, the blood vessel is compressed and cannot be used for a long time.

  In addition, unlike the case of the wrist, the method of arranging a photoelectric pulse wave sensor at the base of the finger and wiring it with a wristwatch type calculation display unit is unlikely to shift the position of the pulse wave sensor during exercise. However, the movement of the subject is constrained by the line connected between the finger and the wrist. Also, in terms of appearance, there is little discomfort during exercise such as jogging or marathon, but the scene where a line exists between the finger and wrist in everyday life feels discomfort. Also, in the method of attaching a pulse wave sensor with a belt near the heart and transmitting data wirelessly to a display device attached to the wrist, it is possible to measure the pulse rate without being affected by noise even during intense exercise, There is a problem that it is difficult to use easily because a troublesome act of wrapping a belt around the chest is necessary before measurement.

  Therefore, in the present invention, in order to eliminate the above-described problems caused by the prior art, a pulse rate measurement that can be performed during exercise and can be performed for a long time without tightening the wrist, with the device provided only around the wrist. The purpose is to provide a device.

  In order to solve these problems, the pulse rate measuring apparatus according to the present invention employs the following means. That is, the present invention relates to a pulse rate measuring device that detects a pulse wave of a subject and measures the pulse rate, and detects a pulse wave with a thin pressure sensor composed of a conductive thin film and a piezoelectric thin film, and the thin pressure sensor and the thin pressure sensor The calculation means for calculating the pulse rate from the pulse wave detected by the above and the display means for displaying the pulse rate calculated by the calculation means are attached to one wrist of the subject.

  In the thin pressure sensor of the present invention, it is preferable to dispose electrodes made of a conductive thin film on both surfaces of a piezoelectric thin film layer made of a piezoelectric thin film.

  In the present invention, the piezoelectric thin film and the conductive thin film are preferably made of a flexible material, and the thin pressure sensor is preferably deformable.

  The piezoelectric thin film in the present invention is preferably made of aluminum nitride, barium titanate, lead zirconate titanate, or a polyvinylidene fluoride polymer.

  The thin pressure sensor in the present invention preferably has two or more piezoelectric thin film layers.

  Further, in the present invention, when measuring the pulse rate, it is preferable that the thin pressure sensor, the calculation means, and the display means are arranged around the wrist of the subject with a band.

  Moreover, it is preferable that the thin pressure sensor in this invention is affixed inside a band.

  Further, the thin pressure sensor in the present invention is preferably embedded in the band.

  In the present invention, it is preferable to dispose one thin pressure sensor on or in the band.

  In the present invention, it is preferable that a plurality of thin pressure sensors are arranged on or in the band, and the calculation means calculates using signals from the plurality of thin pressure sensors arranged on or in the band.

  Moreover, it is preferable that a part of band in this invention is comprised with the material which can be expanded-contracted, and the said band can expand-contract.

  In addition, a part of the band in the present invention is preferably made of urethane, sponge or gel material.

  Moreover, it is preferable that the calculating means in this invention has a charge voltage conversion means.

  Moreover, it is preferable that the calculating means in this invention has a signal amplification means.

  Moreover, it is preferable that the calculating means in this invention has a means to measure time.

  Moreover, it is preferable that the display means in the present invention displays date, day of the week, or time information.

  Moreover, it is preferable that the calculating means in this invention has a data holding means, and hold | maintains a certain amount of pulse rate data.

  Moreover, it is preferable that the calculating means in this invention has a measured value prediction means for predicting a measured value from immediately preceding data.

  Moreover, it is preferable that the calculating means in this invention has a communication means, and transmits the pulse rate data to a personal computer, PDA or a mobile phone.

  Moreover, it is preferable that the calculating means in this invention has a temperature sensor, and starts the measurement by detecting the body temperature when the apparatus touches the skin.

  Moreover, it is preferable that the calculating means in this invention has an electric current detection part, and detects the weak electric current which is flowing into the human body when an apparatus touches skin, and starts a measurement.

  Moreover, it is preferable that the display means in this invention has a means to display that the pulse wave has been detected normally.

  Moreover, it is preferable that the means for displaying that the pulse wave can be normally detected in the present invention blinks a point, a line or a figure in synchronization with the pulse.

(Function)
In a pulse rate measuring device that detects a subject's pulse wave using a pressure sensor, a thin pressure sensor that detects the pulse wave, a calculation unit that calculates the pulse rate, and a display unit that displays the pulse rate are displayed in a band. It is placed on one wrist and measures the pulse rate of the subject from the pulse wave detected by the thin pressure sensor, so that it can be measured not only at rest but also during exercise with the device installed only around the wrist. Long time measurement is possible without tightening.

  As described above, the pulse rate measuring device of the present invention has the effects described below.

In a pulse rate measuring device that detects a subject's pulse wave using a pressure sensor, the pulse wave is detected by a thin pressure sensor comprising a conductive thin film and a piezoelectric thin film, and the pulse detected by the thin pressure sensor and the thin pressure sensor is detected. A calculating means for calculating the pulse rate from the wave and a display means for displaying the pulse rate calculated by the calculating means are arranged on one wrist of the subject with a band, and based on the pulse wave detected by the thin pressure sensor, By measuring the pulse rate, unlike the optical type, the thin pressure sensor is highly sensitive and can detect the pulse wave in a wide area. For example, when the subject moves, the sensor position is in the initial state. Even in the case of deviation from the above, the pulse rate can be measured. In addition, this eliminates the need to completely fix the position of the sensor to the wrist, so measurement can be performed without tightening the wrist, and pulse rate measurement can be performed for a long time.

  In the present invention, when measuring the pulse rate, since the pulse rate measuring device is provided only around one wrist of the subject, the activity of the subject is not limited by wiring or the like. However, it can be easily worn in a short time without changing from a normal wristwatch.

  In addition, in the present invention, by using a low-repulsive substance such as urethane in a part of the band, the thin pressure sensor can easily contact the wrist and detect a pulse wave, and an external impact etc. directly reaches the sensor. Therefore, stable measurement is possible. In addition, when measuring the pulse rate, it has a function to predict the measured value from the measured value several seconds before, so that the wrong pulse rate is not transmitted to the subject even if an erroneous measured value is calculated due to noise etc. Is possible.

  Furthermore, the pulse rate measuring device according to the present invention can be used as a wristwatch when the pulse rate is not measured.

  Hereinafter, an optimal embodiment of a pulse rate measuring apparatus using the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a first embodiment of the present invention. In FIG. 1, it is assumed that the pulse rate measuring device is attached to the wrist of the subject. The device is arranged around the wrist by a band 103, and a thin pressure sensor 101 is arranged on the wrist side of the band. Here, as shown in FIG. 2A, the thin pressure sensor 101 includes a piezoelectric thin film layer 201 and a conductive thin film layer 202. The piezoelectric thin film layer 201 and the conductive thin film layer 202 are both flexible. Have sex. In this embodiment, aluminum nitride is used for the piezoelectric thin film layer 201 and aluminum is used for the conductive thin film layer 202. Here, the piezoelectric thin film layer 201 and the conductive thin film layer 202 are not limited thereto, and the piezoelectric thin film layer may be a conductive film such as a thin film of barium titanate, lead zirconate titanate, or polyvinylidene fluoride polymer. Examples of the body thin film layer include various metal films such as titanium and gold.

  Moreover, as the thin pressure sensor 101, the thing of a multilayer structure as shown in FIG.2 (b) is also considered. FIG. 2B shows a structure in which the piezoelectric thin film layer 201 is sandwiched between the external electrode layer 203 and the internal electrode layer 204. Since there are two piezoelectric thin film layers 201, the pressure sensitivity is almost doubled. is there. In addition, by using a multilayer structure, leakage of charges on the internal electrode to the outside can be prevented, and the influence of noise can be reduced. The thin pressure sensor 101 detects the pressure as a charge signal when pressure is applied to the thin film surface. In FIG. 1, in order to improve the adhesion between the thin pressure sensor 101 and the wrist, a low-repulsive substance 104 such as a low-repulsive urethane is disposed inside the band 103, and the thin pressure sensor 101 is disposed thereon. Is affixed. Here, in the present embodiment, the thin pressure sensor 101 is affixed to the surface, but it can be embedded in the band 103 or the low repulsion substance 104 as long as the pulse wave can be detected.

A calculation / display unit 102 is arranged on the band 103. The place to be arranged is preferably the palm side or the back side of the hand where the subject can easily see the display. Moreover, in this embodiment, although the calculating part and the display part are integrated, it is good also as separate. The calculation / display unit 102 is connected to the thin pressure sensor 101 through a signal line, and a signal from the thin pressure sensor 101 is transmitted to the calculation / display unit 102. In the present embodiment, the signal line is embedded in the band and does not appear on the surface of the apparatus. The display area in the calculation / display unit 102 includes an area 105 that displays the measured pulse rate, an area 106 that blinks in synchronization with the pulse timing, and an area 107 that displays other information. The portion 106 that blinks in synchronization with the timing of the pulse can inform the subject that measurement is being performed normally by this display. In the area 107 for displaying other information, the time, date, day of the week, timer time, etc. are displayed.

  Here, when the band 103 is attached to the wrist, since the low-repulsive substance 104 is disposed inside the band 103, the thin pressure sensor 101 is disposed at a place where it comes into contact with the skin. The low resilience material 104 also prevents external impacts from being directly transmitted to the thin pressure sensor 101. At this time, by attaching the band so that the thin pressure sensor 101 is on the palm side of the wrist, the thin pressure sensor 101 can obtain a large pulse wave signal from the artery, and by calculating the period of this signal waveform, the pulse The number can be measured. Since the signal obtained by the thin pressure sensor 101 is a charge signal, a voltage signal as shown in FIG. 3 can be obtained by providing the calculation / display unit 102 with charge voltage conversion means such as a charge amplifier. It becomes possible.

  As a flow for actually measuring the pulse rate, a block diagram is shown in FIG. 4. First, the thin pressure sensor 101 is first placed on the palm side of the wrist, and the subject turns on the pulse rate measurement start switch 108, for example. By starting the measurement, acquisition of a charge signal having pulse wave information is started. Here, since the thin pressure sensor 101 has very high sensitivity, even if the thin pressure sensor 101 is deviated from the position where it was initially placed, it is possible to detect a pulse wave if the human body is touched. Further, since the area is as wide as 1.5 cm × 3.5 cm, for example, the intensity of the obtained signal is not attenuated with respect to the deviation within this range. Next, the charge signal from the thin pressure sensor 101 is input to the calculation / display unit 102. The calculation / display unit 102 mainly includes a calculation unit 401 and a display unit 402, and operates by being supplied with power from a power source 411. The calculation / display unit 102 includes a time measurement unit 410, and the time measurement function is used for pulse rate calculation, date, day of the week, and time display, and a timer function.

  The charge signal is converted into a voltage signal by charge voltage conversion means 403 such as a charge amplifier in the arithmetic unit 401. Here, as the conversion, for example, a method of converting a charge amount for a certain time into a voltage signal can be considered. Next, the signal converted into the voltage is input to the data holding unit 404. Here, when the signal converted into the voltage by the charge voltage conversion means 403 is small, it is conceivable to amplify the signal using the signal amplification means. The data holding unit 404 holds the input voltage data. Among the signals input to the data holding unit 404, a signal corresponding to a certain time width is input to the pulse rate calculating unit 405 and used for calculating the pulse rate. . Here, as data input to the pulse rate calculation unit 405, for example, data as shown in FIG. 3 can be considered. At this time, there are several possible methods for calculating the pulse rate. For example, the voltage signal is differentiated and the pulse rate is calculated from the value obtained by counting the number of times that the differential signal becomes 0 within a certain time, or the threshold of the voltage level is set in advance, A method that counts the number of times that the threshold value is not exceeded, a method that integrates the voltage signal around the steady state, counts the number of times the positive / negative changes within a certain time, and calculates the pulse rate, or a combination of these methods A method of calculating the pulse rate by using the above method is mentioned.

In addition to the above method, it is also conceivable to use the measurement value predicting unit 406 in measuring the pulse rate. The measurement value prediction function in the measurement value prediction unit 406 is a function that predicts a value to be measured from a measurement value several seconds before. When this function is used, a measurement value that is significantly different from the expected pulse rate is indicated. For example, it is possible to take measures such as not displaying the measured value. As an example, the pulse value measured 1 second after that was 2 due to the influence of noise due to some body movement, etc., even though the pulse rate measured 2 seconds before and 1 second ago were both 70. Such a sudden change in the pulse rate is unlikely to occur in practice, so there are cases where the display is not switched.

  The pulse rate data calculated by the pulse rate calculation unit 405 is input to the pulse rate display unit 407, and the pulse rate is displayed. The display of the pulse rate is preferably one in which the display is switched in a certain unit of time. For example, the display of the pulse rate is updated every second. In addition, the display unit 402 includes a time information display unit 409 that displays the date, day of the week, and time, and a timer display, and a pulse wave information display unit 408 that displays that the subject can detect the pulse wave normally. Have. The pulse wave information display unit 408 may be a method of blinking a heart symbol or the like in synchronization with the pulse wave cycle, for example, and this display may confirm whether the subject has detected a pulse wave. it can.

  In addition, the calculation / display unit 102 according to the present embodiment has a communication means, and by transmitting pulse rate data for a certain period to a personal computer, PDA, mobile phone, etc., it is possible to observe changes in the pulse rate over time, etc. It can be saved as pulse rate data.

  In this embodiment, the band 103 is provided with the low-repulsive material 104 in order to keep the wrist and the thin pressure sensor 101 in close contact with each other. However, the present invention is not limited to this. The wrist and the thin pressure sensor 101 can be brought into close contact with each other by using a simple material and making the band extendable and contractible.

  In the above-described embodiment, when starting measurement of the pulse rate, measurement is started by turning on a pulse rate measurement start switch or the like. However, the present invention is not limited to this. For example, the apparatus uses a temperature sensor. When the subject wears the device on his arm and starts measuring by detecting the body temperature when the device touches the skin, or when the device has a current detector and the device touches the skin It is also conceivable that a weak current flowing through the human body is detected and measurement is started.

  Moreover, in the above-mentioned embodiment, this apparatus can also be used as a wristwatch when pulse rate measurement is not performed.

(Second embodiment)
Next, a second embodiment will be described. FIG. 5 is a diagram showing a second embodiment of the present invention. The components of the pulse rate measuring device such as the thin pressure sensor and the calculation / display unit in the present embodiment are the same as those in the first embodiment. In FIG. 5, it is assumed that the pulse rate measuring device is attached to the wrist of the subject. The device is arranged around the wrist by a band 103, and a first thin pressure sensor 501 and a second thin pressure sensor 502 are arranged on the wrist side of the band. Here, the first thin pressure sensor 501 and the second thin pressure sensor 502 are both composed of a piezoelectric thin film layer and a conductive thin film layer, as in the first embodiment, and have flexibility. When pressure is applied to the thin film surface, the pressure is detected as a charge signal. Here, the first thin pressure sensor 501 and the second thin pressure sensor 502 can detect a pulse wave signal by being in close contact with the wrist.

At this time, since the first thin pressure sensor 501 and the second thin pressure sensor 502 are very sensitive, even if the first thin pressure sensor 501 and the second thin pressure sensor 502 are deviated from the positions where they are initially arranged, a pulse wave is detected if they are touching the human body. In addition, since the area thereof is as wide as 1.5 cm × 3.5 cm, the intensity of the obtained signal is not attenuated with respect to the deviation within this range. Therefore, the first thin pressure sensor 501 and the second thin pressure sensor 502 are disposed relatively far apart, for example, at positions opposite to the inner side of the band, that is, on the palm side and the back side of the hand. Even if the band is arranged on the wrist in any direction, a large pulse wave signal can be detected. Next, signals from the first thin pressure sensor 501 and the second thin pressure sensor 502 are input to the calculation / display unit 102, and the calculation / display unit 102 selects a signal having a strong signal strength. Thereafter, the pulse rate is measured based on the selected signal as in the first embodiment. As a method of measurement, for example, from a pulse wave data as shown in FIG. 3, for example, a voltage signal is differentiated, and a pulse rate is calculated from a value obtained by counting the number of times that the differential signal becomes 0 within a certain time, The threshold of the voltage level is set in advance, the number of times the threshold value is exceeded or less than the threshold value within a certain time, the voltage signal is integrated with the steady state as the axis, and the positive / negative is switched within a certain time A method of counting the number of times and calculating the pulse rate, or a method of calculating the pulse rate by a combination of these methods may be mentioned. By inputting the measured pulse rate to the display unit, the pulse rate is displayed, and the subject can visually recognize the pulse rate.

  In the above-described embodiment, two thin pressure sensors are used. However, the present invention is not limited to this, and the present technique is effective even when three or more pressure sensors are used.

  Further, as in the first embodiment, this apparatus can be used as a wristwatch when pulse rate measurement is not performed.

It is a figure which shows the structure of the pulse rate measuring apparatus in 1st embodiment of this invention. It is a figure which shows the structure of the thin pressure sensor in embodiment of this invention. It is a figure which shows the pulse wave signal in embodiment of this invention. It is a block diagram at the time of performing pulse rate measurement in the embodiment of the present invention. It is a side view of the pulse rate measuring device in a second embodiment of the present invention.

Explanation of symbols

101 Thin Pressure Sensor 102 Calculation / Display Unit 103 Band 105 Pulse Rate Display Area 201 Piezoelectric Thin Film Layer 202 Conductor Thin Film Layer 501 First Thin Pressure Sensor 502 Second Thin Pressure Sensor

Claims (23)

A pulse rate measuring device for detecting a pulse wave of a subject and measuring a pulse rate, wherein the pulse wave is detected by a thin pressure sensor including a conductive thin film and a piezoelectric thin film, and the thin pressure sensor and the thin pressure sensor A pulse rate measuring device in which a calculating means for calculating the pulse rate from the pulse wave detected by the means and a display means for displaying the pulse rate calculated by the calculating means are attached to one wrist of the subject. 2. The pulse rate measuring device according to claim 1, wherein the thin pressure sensor has electrodes formed of the conductive thin film disposed on both sides of a piezoelectric thin film layer formed of the piezoelectric thin film. The pulse rate measuring device according to claim 1 or 2, wherein the piezoelectric thin film and the conductive thin film are made of a flexible material, and the thin pressure sensor is deformable. The pulse rate measuring device according to any one of claims 1 to 3, wherein the piezoelectric thin film is made of aluminum nitride, barium titanate, lead zirconate titanate, or a polyvinylidene fluoride polymer. . The pulse rate measuring device according to any one of claims 2 to 4, wherein the thin pressure sensor includes two or more piezoelectric thin film layers. When measuring a pulse rate, the said thin pressure sensor, the said calculating means, and the said display means are arrange | positioned around a test subject's wrist by a band, The Claim 1 characterized by the above-mentioned. Pulse rate measuring device. The pulse rate measuring device according to claim 6, wherein the thin pressure sensor is attached to the inside of the band. The pulse rate measuring device according to claim 6, wherein the thin pressure sensor is embedded in the band. The pulse rate measuring device according to any one of claims 6 to 8, wherein one thin pressure sensor is disposed on or in the band. A plurality of the thin pressure sensors are arranged on or in the band, and the calculation means calculates using signals from the plurality of thin pressure sensors arranged on or in the band. The pulse rate measuring device according to any one of claims 6 to 8. The pulse rate measuring device according to any one of claims 6 to 10, wherein a part of the band is made of a stretchable material, and the band is stretchable. The pulse rate measuring device according to any one of claims 6 to 11, wherein a part of the band is made of urethane, sponge or gel material. The pulse rate measuring device according to any one of claims 1 to 12, wherein the arithmetic unit includes a charge voltage conversion unit. The pulse rate measuring apparatus according to any one of claims 1 to 13, wherein the arithmetic means includes a signal amplifying means. The pulse rate measuring apparatus according to any one of claims 1 to 14, wherein the calculating means includes means for measuring time. The pulse rate measuring device according to any one of claims 1 to 15, wherein the display means displays date, day of the week, or time information. The pulse rate measuring apparatus according to any one of claims 1 to 16, wherein the calculation unit includes a data holding unit, and holds a certain amount of the pulse rate data. The pulse rate measuring device according to any one of claims 1 to 17, wherein the calculation unit includes a measurement value prediction unit that predicts a measurement value from immediately preceding data. The pulse rate measuring device according to any one of claims 1 to 18, wherein the calculation unit includes a communication unit, and transmits the pulse rate data to a personal computer, a PDA, or a mobile phone. The pulse rate measuring device according to any one of claims 1 to 19, wherein the calculating means includes a temperature sensor, and starts measurement by detecting a body temperature when the skin is touched. The said calculating means has an electric current detection part, detects the electric current which is flowing into the human body when it touches skin, and starts a measurement, It is any one of Claims 1-20 characterized by the above-mentioned. Pulse rate measuring device. The pulse rate measuring apparatus according to any one of claims 1 to 21, wherein the display means includes means for displaying that a pulse wave is normally detected. 23. The pulse rate measuring apparatus according to claim 22, wherein the means for displaying that the pulse wave is normally detected blinks a point, a line or a figure in synchronization with the pulse.

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