JP6381976B2 - Biological information measuring device and biological information measuring cuff - Google Patents

Description

  The present invention relates to a biological information measuring device that measures biological information using electrodes, and a biological information measuring cuff.

  Conventionally, a plurality of electrodes are pasted on the body surface of a subject, a current is passed through the human body through the electrodes, a potential difference (voltage) between the electrodes is detected, and the electrical impedance of the human body based on the potential difference An apparatus for measuring biological information such as a respiratory state, a pulse wave, and a blood flow state by detecting a change has been developed.

  For example, Patent Document 1 discloses an apparatus for measuring a respiratory state by detecting an impedance variation that varies according to respiration. For example, Patent Document 2 discloses a technique for detecting an impedance pulse wave using a pair of electrodes attached so as to sandwich the chest, and calculating the pulse wave propagation velocity using the impedance pulse wave. Yes.

JP 2013-063186 A Japanese Patent No. 3696978

  By the way, in an apparatus for obtaining biological information by measuring impedance as described above, an electrode for measuring impedance needs to be attached to a predetermined position on the body surface of the subject. For this reason, the medical staff will take time and labor for the examination. In addition, some subjects feel uncomfortable because the electrodes directly touch the body surface.

  The present invention has been made in consideration of the above points, and the biological information measuring device that can reduce the labor required for electrode mounting of medical personnel and the discomfort caused by the electrode touching the skin of the subject, And a biological information measurement cuff.

One aspect of the biological information measuring device of the present invention is:
A first electrode comprising at least one electrode;
A second electrode comprising at least one electrode;
A cuff for accommodating the first electrode in a belt such that at least a portion of the first electrode is not exposed;
When the first and second electrodes are regarded as a capacitor using a human body of the subject and other substances electrically sandwiched by the first and second electrodes as a capacitor, the capacitor is included. A resonant circuit,
A current supply for supplying a high-frequency constant current to the first and second electrodes;
A detector that detects an impedance variation based on a voltage change of the first and second electrodes, and detects biological information based on the impedance variation;
Have

One aspect of the biological information measuring device of the present invention is:
With the first cuff,
The second cuff,
An electrode that is provided in each of the first cuff and the second cuff, and at least a part of which is accommodated in the belts of the first and second cuffs and not exposed to the cuff surface;
When the electrodes of the first and second cuffs are regarded as capacitors having a human body of a subject and other substances electrically sandwiched by the electrodes of the first and second cuffs as dielectrics, A resonant circuit including a capacitor;
A current supply for supplying a high frequency constant current to the electrodes of the first cuff and the second cuff;
A detecting unit that detects impedance fluctuation based on a voltage change of the electrodes of the first cuff and the second cuff, and detects biological information based on the impedance fluctuation;
Have

One aspect of the biological information measurement cuff of the present invention is:
A bag-like belt wrapped around the upper or lower limbs;
An air bag provided in the belt;
A planar electrode that is at least partially contained within the belt and not exposed to the belt surface;
I have a,
The planar electrode is
A supply electrode for supplying current to the subject for measuring biological information;
A detection electrode for detecting the voltage of the subject;
Have
The supply electrode is accommodated in the belt and is not exposed on the belt surface,
The detection electrode is not accommodated in the belt and is exposed on the belt surface .

  According to the present invention, since at least one of the plurality of electrodes for measuring impedance is provided in the cuff, the electrode is easily and accurately attached to the subject, and the impedance is measured as compared with the conventional case. become able to. In addition, since the resonance circuit is configured, it is possible to pass a current through the subject without directly touching the electrode on the subject's skin, so that all or at least a part of the electrode is directly applied to the subject's skin. Impedance can be measured without touching. Accordingly, it is possible to realize a biological information measuring device and a biological information measuring cuff that can reduce labor and time required for medical staff to wear electrodes, and discomfort due to the electrodes touching the skin of the subject.

Basic configuration diagram of the embodiment The block diagram which shows the whole structure of the biological information measuring device which concerns on embodiment Flow chart showing the calculation procedure of pulse wave velocity using impedance pulse wave and pressure pulse wave Diagram for explaining the propagation time of pulse wave from impedance pulse wave and pressure pulse wave The top view which looked at the 1st cuff and the 2nd cuff from the inner surface (mounting surface) direction A-A 'sectional view of FIG. Diagram for explaining electrical connection and operation of each electrode The figure which shows the structure at the time of providing one electrode in each cuff The figure which shows the constitution to cope with when there is an insulator The figure which shows the constitution to cope with when there is an insulator Sectional drawing which shows the state which has arrange | positioned the electrode inside an arm band (foot band) Sectional drawing which shows the state which covered the electrode with cloth Diagram showing the configuration where the voltage measurement circuit is also a resonant circuit The top view which shows arrangement | positioning of the electrode in other embodiment

  FIG. 1 is a basic configuration diagram of the present embodiment. 1 includes a first cuff 20, a second cuff 30, electrodes 21 and 22 provided on the first cuff 20, electrodes 31 and 32 provided on the second cuff 30, Have

  Further, the biological information measuring apparatus 10 electrically connects the electrodes 21, 22, 31, 32 of the first and second cuffs 20, 30 by the electrodes 21, 22, 31, 32 of the first and second cuffs 20, 30. When it is regarded as a capacitor in which the human body 40 and other substances of the subject to be sandwiched are regarded as a capacitor, a resonance circuit including the capacitor is provided. In order to form a resonance circuit, a coil 50 is provided in the example of FIG.

  In addition, the biological information measuring apparatus 10 includes a high frequency constant current power source 60 that supplies a high frequency constant current to the electrode 21 of the first cuff 20 and the electrode 31 of the second cuff 30.

  Furthermore, the biological information measuring apparatus 10 detects an impedance variation based on the voltage of the electrode 22 of the first cuff 20 and the electrode 32 of the second cuff 30 and detects a biological information based on the impedance variation. Have. Actually, the detection unit 70 includes a voltmeter and a filter, and extracts a frequency component corresponding to the biological information to be measured from the voltage measured by the voltmeter. That is, when detecting a pulse wave or a respiration state as biometric information, these biometric information have different frequency bands. Therefore, by separating them with a filter, an impedance variation corresponding to each biometric information is extracted. Each biological information can be obtained based on the impedance variation.

  As described above, since the resonance circuit is provided, it is possible to flow current to the subject without directly touching the electrode on the subject's skin. Impedance can be measured without touching the skin directly. In addition, since the electrodes are provided on each of the first cuff 20 and the second cuff 30, the impedance can be measured only by attaching the first cuff 20 and the second cuff 30 to the subject.

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

  In the following embodiments, the case where the biological information measuring device according to the present invention is applied to a device for measuring a pulse wave velocity (PWV) is described. However, the biological information measuring device according to the present invention is described below. Is widely applicable not only to measuring PWV, but also to devices that measure biological information based on impedance fluctuations.

  FIG. 2 is a schematic diagram showing the overall configuration of the biological information measuring apparatus according to the embodiment of the present invention.

  The biological information measuring apparatus 100 includes a first cuff 110 and a second cuff 120. A first electrode 111 and a second electrode 121 are provided on each of the first cuff 110 and the second cuff 120. The first cuff 110 is attached to the subject's upper limb, and the second cuff 120 is attached to the subject's lower limb. In the present embodiment, the first cuff 110 is attached to the left upper arm, and the second cuff 120 is attached to the right ankle.

  Furthermore, the biological information measuring apparatus 100 includes a blood pressure pulse wave measurement unit 130, an impedance pulse wave measurement unit 140, an electrocardiogram measurement unit 150, a control / calculation unit 160, a storage unit 171, an input unit 172, a display unit 173, an audio unit 174, and the like. A printing unit 175 is included.

  The control / calculation unit 160 includes a CPU (Central Processing Unit), a memory, and the like, and controls the operation of each unit in the apparatus by executing a biological information measurement program stored in the memory by the CPU. Perform operations necessary to obtain information.

  The storage unit 171 is a storage device such as a hard disk, and stores measurement results and the like under the control of the control / calculation unit 160. The input unit 172 includes an input device such as a keyboard, a mouse, or a button, and outputs an operation signal corresponding to a user operation to the control / calculation unit 160. The control / calculation unit 160 performs control and calculation according to the operation signal. The display unit 173 is a display device such as a liquid crystal display, and displays a setting screen, operation guidance, a biological information test result report, or the like under the control of the control / calculation unit 160. Note that the display unit 173 may be configured by a touch panel and may have an input function in addition to the display function. The voice unit 174 is a speaker device, and outputs operation guidance or an alarm sound according to the control of the control / calculation unit 160. The printing unit 175 is a printer device such as a thermal printer, and prints a biological information test result report or the like under the control of the control / calculation unit 160.

  The blood pressure pulse wave measurement unit 130 includes a pump and an exhaust valve for supplying and exhausting the cuffs 110 and 120, a pressure sensor for detecting the pressure of the cuffs 110 and 120, and a predetermined signal such as amplification for a detection signal from the pressure sensor. It comprises a signal processing circuit that performs the signal processing. The blood pressure pulse wave measurement unit 130 increases the internal pressure of the cuffs 110 and 120 (hereinafter, the internal pressure of the cuff is referred to as “cuff pressure”) by introducing air into the air bags of the cuffs 110 and 120 through the hose, The cuff pressure of the cuffs 110 and 120 is reduced by discharging air from the air bag. The target value of the cuff pressure after pressurization is different between the pressure pulse wave measurement and the blood pressure measurement, and can be set individually.

  In the case of the present embodiment, measurement of the pressure pulse wave and measurement of the impedance pulse wave are performed simultaneously.

  The measurement of the pressure pulse wave can be performed using both the first cuff 110 and the second cuff 120, or either the first cuff 110 or the second cuff 120. In the case of the present embodiment, The pressure pulse wave is measured using the second cuff 120 attached to a site far from the heart 200. Thereby, since the propagation path of a pulse wave becomes long, the measurement accuracy of PWV improves.

  When measuring a pressure pulse wave and an impedance pulse wave, the blood pressure pulse wave measurement unit 130 first pressurizes the cuff pressures of the cuffs 110 and 120 until a predetermined value is reached. Here, the reason why the cuff 110 that does not measure the pressure pulse wave is also pressurized is to make the electrode 111 provided on the cuff 110 as close as possible to the subject in order to measure the impedance pulse wave. In the present embodiment, the cuff pressure when measuring the pressure pulse wave and the impedance pulse wave is controlled to 30 to 40 mHg.

  The blood pressure pulse wave measurement unit 130 detects a change in the cuff pressure of the cuff 120 after pressurization with a pressure sensor as a pressure pulse wave signal, and outputs the detected pressure pulse wave signal to the control / calculation unit 160.

  On the other hand, in the case of blood pressure measurement, the blood pressure pulse wave measurement unit 130 detects the cuff pressure vibration of the cuff 110 and / or 120 with the pressure sensor during decompression, and uses the cuff pressure at the time when the amplitude starts to increase as the systolic blood pressure. While detecting, the cuff pressure with the most remarkable vibration reduction is detected as the diastolic blood pressure. Then, the blood pressure pulse wave measurement unit 130 outputs blood pressure signals respectively indicating the detected systolic blood pressure and diastolic blood pressure to the control / calculation unit 160.

  The electrocardiogram measurement unit 150 is connected to electrodes 111 and 121 provided in the cuffs 110 and 120. The electrocardiogram measurement unit 150 includes a signal processing circuit that performs predetermined signal processing such as amplification on the detection signals detected by the electrodes 111 and 121. The electrocardiogram measurement unit 150 outputs the detection signal after signal processing to the control / calculation unit 160 as an electrocardiogram signal.

  The impedance pulse wave measurement unit 140 includes a high-frequency constant current power source (corresponding to the high-frequency constant current power source 60 in FIG. 1) that supplies a high-frequency constant current to the electrodes 111 and 121, and the electrodes 111 and 121 when the high-frequency constant current is supplied. A voltmeter (corresponding to the detection unit 70 in FIG. 1) that measures the voltage between them, and an impedance pulse wave forming unit that obtains an impedance pulse wave based on the measured voltage.

  The measurement principle of the impedance pulse wave is based on the fact that the impedance in the path through the heart 200 changes according to the blood flow volume and the blood red blood cell arrangement, as already known. Specifically, the impedance decreases as the blood flow volume increases and the blood red blood cells align. Here, before the aortic valve is opened, since there is almost no aortic blood flow and the blood arrangement is random, the impedance increases. On the other hand, after the aortic valve is opened, an aortic pulsating flow is generated, the blood flow volume is increased, and blood red blood cells are also aligned when passing through the aortic valve, so that the impedance is reduced. The impedance pulse wave is obtained by measuring the impedance that varies with the pulsatile flow from such an aortic valve. By observing the impedance pulse wave, the timing at which blood is ejected from the aortic valve can be detected. By detecting the ejection timing of blood from the heart using the impedance pulse wave, the blood ejection timing from the heart can be detected with high accuracy because the blood flow is directly detected. On the other hand, in the method of detecting the ejection timing of blood from the heart by detecting the movement of the heart using a piezoelectric sensor or the like, the blood flows after the heart starts to move according to the presence or absence of heart disease or blood pressure. Since the time interval until ejection is different, it is difficult to accurately estimate the ejection timing of blood from the motion of the heart.

  Here, the frequency of the high-frequency constant current generally used for measuring the impedance pulse wave is around 50 kHz, while the electrocardiogram component is at most about 100 Hz, and the frequency band is greatly separated. Therefore, even if they are mixed, the component of the impedance pulse wave and the component of the electrocardiogram can be easily separated by a technique such as filtering, so the measurement by the impedance pulse wave measurement unit 140 and the measurement by the electrocardiogram measurement unit 150 are performed simultaneously. be able to.

  Next, a method for calculating PWV using an impedance pulse wave and a pressure pulse wave will be described with reference to FIGS. 3 and 4. Note that the calculation of PWV using the impedance pulse wave and the pressure pulse wave is a known method disclosed in, for example, Patent Document 2 and will be briefly described here.

  In calculating the PWV, the control / calculation unit 160 executes the processing procedure shown in FIG. When starting the PWV calculation process in step S0, the control / calculation unit 160 sets the cuff pressures of the cuffs 110 and 120 that are pressurized by the blood pressure pulse wave measurement unit 130 in step S1. In the case of the present embodiment, the cuff pressure is set to 30 to 40 mHg. Subsequently, in step S2, the impedance pulse wave measured by the impedance pulse wave measuring unit 140 is read, and in step S3, the pressure pulse wave measured by the blood pressure pulse wave measuring unit 130 is read.

  FIG. 4 shows the state of the impedance pulse wave and the pressure pulse wave read in steps S2 and S3. In FIG. 4, the time axis of the impedance pulse wave and the pressure pulse wave is shown in accordance with the same time axis. Further, the vertical axis of the impedance pulse wave is shown so that the direction in which the impedance decreases becomes the upward direction.

  In step S4, the control / calculation unit 160 detects a changing point where the impedance of the impedance pulse wave becomes small and a changing point where the pressure pulse wave becomes large. In detecting this conversion point, for example, a differential method or the like can be used. In the example of FIG. 4, the impedance pulse wave has the above-mentioned changing point at the time point t1, and the pressure pulse wave has the above-mentioned changing point at the time t2.

  In step S <b> 5, the control / calculation unit 160 calculates t <b> 2-t <b> 1, thereby calculating the pulse wave propagation time T from the heart 200 to the attachment site of the second cuff 120. Next, in step S6, the control / calculation unit 160 calculates PWV by calculating T / L using a preset distance L from the heart 200 to the wearing site of the second cuff 120.

  FIG. 5 is a plan view of the first cuff 110 and the second cuff 120 of the present embodiment as viewed from the inner surface (mounting surface) direction, and FIG. 6 is a cross-sectional view showing the AA ′ cross section of FIG. is there.

  The first cuff 110 has an arm band 112 wound around the arm, an air bag 113 provided in the arm band 112, and an electrode 111 fixedly provided on the surface of the arm band 112. The electrode 111 includes two electrodes 111 a and 111 b that are provided at a predetermined interval in the width direction of the first cuff 110.

  Each electrode 111a, 111b is provided so as to extend in the longitudinal direction of the first cuff 110. The electrodes 111a and 111b are made of a metal foil such as copper. Note that it is preferable to form the electrodes 111a and 111b with a conductive cloth because the touch is improved. The conductive cloth may be made from highly conductive fibers.

  A hose 114 connected to the blood pressure pulse wave measurement unit 130 is attached to the air bag 113. In addition, a lead wire (not shown) is attached to each of the electrodes 111a and 111b. Both lead wires attached to the respective electrodes 111a and 111b are connected to the impedance pulse wave measuring unit 140, and any one of the lead wires attached to the respective electrodes 111a and 111b is connected to the electrocardiogram measuring unit 150. It is connected.

  Similarly, the second cuff 120 includes a foot band 122 wound around the ankle, an air bag 123 provided in the foot band 122, and an electrode 121 fixed to the surface of the foot band 122. The electrode 121 includes two electrodes 121 a and 121 b provided at a predetermined interval in the width direction of the second cuff 120. Each of the electrodes 121 a and 121 b is provided so as to extend in the longitudinal direction of the second cuff 120. The electrodes 121a and 121b are made of a metal foil such as copper. Note that it is preferable to form the electrodes 121a and 121b with a conductive cloth because the touch is improved. A hose 124 connected to the blood pressure pulse wave measurement unit 130 is attached to the air bag 123. Moreover, a lead wire (not shown) is attached to each electrode 121a, 121b. Both lead wires attached to the electrodes 121a and 121b are both connected to the impedance pulse wave measurement unit 140, and any one of the lead wires attached to the electrodes 121a and 121b is connected to the electrocardiogram measurement unit 150. It is connected.

  FIG. 7 is a diagram for explaining the electrical connection and operation of the electrodes 111a, 111b, 121a, and 121b.

  The high frequency constant current power source 141 and the voltmeter 142 are provided in the impedance pulse wave calculation unit 140. The electrodes 111b and 121b are connected to the high-frequency constant current power source 141, whereby a high-frequency constant current is supplied between the electrodes 111b and 121b. The voltage between the electrodes 111a and 121a arranged on the inner side (closer to the heart 200) than the electrodes 111b and 121b is measured by the voltmeter 142, and the impedance pulse wave measuring unit 140 is based on the measured voltage. (That is, impedance in a path through the heart 200) is measured. Since the method for obtaining the impedance pulse wave is a known technique as disclosed in Patent Document 1, description thereof is omitted here. For example, the impedance pulse wave can be detected by extracting a component having a heartbeat-synchronous component as a fundamental wave from the measured impedance by filtering.

  Thus, when a high frequency constant current is supplied to the electrodes 111b and 121b, a current flows between the electrodes 111b and 121b. Since the current value flowing through the electrodes 111b and 121b is a constant current, the voltage value varies depending on the blood ejected from the heart as described above. The impedance pulse wave measurement unit 140 detects this change in voltage value with a voltmeter, and obtains an impedance pulse wave based on the change.

  As described above, the electrodes 111 and 121 are provided on the first cuff 110 and the second cuff 120, respectively, and the impedance pulse wave is measured using the electrodes 111 and 121. Therefore, the first cuff 110 and the second cuff 120 are measured. The impedance pulse wave and the pressure pulse wave can be measured simply by attaching the to the predetermined part of the subject, and the pulse wave propagation velocity with high accuracy can be calculated based on the impedance pulse wave and the pressure pulse wave. As a result, it is possible to measure the pulse wave propagation speed with high accuracy while having a simple configuration with less labor for mounting the measuring tool. That is, as compared with the conventional case where the electrode for impedance pulse wave measurement is provided separately from the cuff, the electrodes 111b and 121b for supplying the high-frequency constant current can be obtained by attaching the cuffs 110 and 120 to a predetermined portion. Since the positional relationship with the voltage detection electrodes 111a and 121a is naturally determined, a good impedance pulse wave can be obtained even if a medical worker does not care about the electrode mounting position.

  Furthermore, it is possible to measure an electrocardiogram and blood pressure using the first cuff 110 and the second cuff 120.

  Moreover, since the electrodes 111 and 121 can be pressed against the human body using the pressure of the cuffs 110 and 120, it does not take time and effort to attach the electrodes to the skin. In addition, the inventors confirmed by experiments that a good impedance pulse wave can be obtained by the electrodes 111 and 121 under a cuff pressure of 30 to 40 mHg suitable for detecting the pressure pulse wave. Yes.

  Furthermore, the biological information measuring apparatus 100 according to the present embodiment can measure the PWV, the timing at which blood is ejected from the heart, and the blood pressure simply by wearing the cuffs 110 and 120. Therefore, the CAVI (Cardio-Ankle Vascular Index) can be obtained easily.

  In the above-described embodiment, the case where the two electrodes 111a, 111b and 121a, 121b are provided on each cuff 110 and 120 has been described. However, one electrode is provided on each cuff 110, 120, and between the electrodes. An impedance pulse wave can also be detected by supplying a high-frequency constant current and detecting the voltage between the electrodes. FIG. 8 is a diagram for explaining the electrical connection and operation of the electrodes 111 and 121 at that time. The voltmeter 142 is connected to the high-frequency constant current power source 141 in parallel, and the voltage drop when the high-frequency constant current is supplied between the electrodes 111 and 121 is measured by the voltmeter 142, thereby changing the impedance between the electrodes 111 and 121. Can be measured. However, in terms of measurement stability, it is preferable to provide two electrodes 111a, 111b and 121a, 121b on each cuff 110 and 120 as in the embodiment. The stability of measurement means that the measurement value is not easily influenced by movements such as breathing and body movement, other than the impedance change caused by blood ejected from the heart to be measured. That is, as in the embodiment, the electrodes 111b and 121b for supplying high-frequency constant current and the electrodes 111a and 121a for measuring voltage are separated from each other as shown in FIG. Compared with the common electrode, the measurement stability becomes higher, and it is possible to obtain a good measurement value of SN with less influence on the measurement value due to respiration or body movement.

  Further, as shown in FIG. 9 in which the same reference numerals are assigned to the corresponding parts as in FIG. 7, by connecting the coil 300 in series with the high-frequency constant current power supply 141 to form a series resonant circuit, the electrode 111 and the skin Even when insulators 301 and 302 such as cloth and clothing are interposed between them, a high-frequency current can flow, so that an impedance pulse wave can be measured.

  Incidentally, the configuration shown in FIGS. 9 to 12 corresponds to the configuration shown in FIG.

  In FIG. 9, the coil 300 is connected between the high-frequency constant current power source 141 and the first electrode 111, but the coil may be connected between the high-frequency constant current power source 141 and the second electrode 121. . The circuit of FIG. 10 shows an equivalent circuit related to the circuit of FIG. 9 (the voltmeter 142 is omitted). The first electrode 111 and the second electrode 121 can be regarded as a capacitor 400 that sandwiches a subject and other cloth or clothing. The human body of the subject and other substances (cloth, clothes, etc.) can be regarded as a dielectric of the capacitor 400. At this time, the inductance of the coil 300 is set so as to match the frequency of the high-frequency constant current supplied by the resonance frequency of the series LC circuit formed by the coil 300 and the capacitor 400, or the frequency of the supplied high-frequency constant current is set to the coil It is set so as to match the resonance frequency of the series LC circuit composed of 300 and the capacitor 400. By doing in this way, even when cloth or clothes are interposed between the electrodes 111 and 121 and the human body (subject), a high-frequency constant current necessary for impedance pulse wave measurement can be passed through the human body. As a result, the impedance pulse wave can be measured.

  Further, if such a resonance configuration is adopted, as shown in FIG. 11 where the same reference numerals are given to the corresponding parts to FIG. 6, the electrodes 111a (111b, 121a, 121b) are connected to the armbands of the cuff 110 (120). Even if it is placed inside 112 (footband 122), the impedance pulse wave can be measured. Similarly, as shown in FIG. 12, the impedance pulse wave can be measured even if the electrode 111a (111b, 121a, 121b) is covered with a cloth 500 or the like. In this way, since the impedance pulse wave can be measured without directly touching the skin of the subject with the electrode, the measurement can be performed without causing the subject to feel uncomfortable. In addition, the electrode can be prevented from being damaged. Further, as shown in FIG. 13 in which the same reference numerals are assigned to the corresponding parts as in FIG. 1, the voltage can be detected with high sensitivity if the coil 51 is also provided in the circuit on the voltage measurement side to configure the resonance circuit. . That is, only the high-frequency constant current supply side may have a resonance circuit configuration as shown in FIG. 1, and both the high-frequency constant current supply side and the voltage measurement side have a resonance circuit configuration as shown in FIG. Also good. Furthermore, only the voltage measurement side may be configured as a resonance circuit. When the voltage measurement side has a resonance circuit configuration, a parallel LC resonance circuit may be formed by connecting a coil in parallel to the detection unit 70.

  However, from the viewpoint of measurement sensitivity, it is better that the electrode for measuring the voltage (in the case of the embodiment, the electrodes 111a and 121a) is in direct contact with the skin of the subject. That is, if a pair of electrodes 111b and 121b to which a high-frequency constant current is supplied interpose a cloth or the like, and the electrodes 111a and 121a for measuring voltage are in direct contact with the skin of the subject, the measurement sensitivity is maintained. The area of the electrode that touches the skin of the subject can be reduced, and the discomfort of the subject can be reduced. If the above-described resonance configuration is employed, if the air bags 113 and 123 are formed of a conductive material, the air bags 113 and 123 can be used as electrodes.

  In addition, since the resonant circuit is formed, it is difficult for a low frequency to flow through the human body, and only a high frequency current can flow. As a result, it is possible to prevent a low-frequency current that is harmful to the human body from flowing by mistake. Therefore, highly safe measurement can be realized.

  In the above-described embodiment, the electrodes 111 and 121 are separated from each other by a predetermined distance in the width direction of the cuffs 110 and 120, and are provided so as to extend in the longitudinal direction of the cuffs 110 and 120, respectively. Although the case where it comprises with 111a, 111b and 121a, 121b was described, arrangement | positioning of the electrodes 111 and 121 is not restricted to this. For example, as shown in FIG. 14 where parts corresponding to those in FIG. 5 are denoted by the same reference numerals, the electrodes 111 and 121 are separated by a predetermined distance in the longitudinal direction of the cuffs 110 and 120, respectively. It may be configured by two electrodes 111a and 111b and 121a and 121b provided so as to extend. However, as shown in FIG. 5, if the electrodes 111 and 121 are provided so as to extend in the longitudinal direction of the cuffs 110 and 120, an area close to or facing the human body becomes large, so that a better impedance pulse wave Can be measured.

  Incidentally, from the viewpoint of measuring the impedance pulse wave, the pair of electrodes 111b and 121b to which the high-frequency constant current is supplied is disposed at a position farther from the heart than the pair of electrodes 111a and 121a to which the voltage is measured. It is preferable. Therefore, the direction in which the cuffs 110 and 120 are attached is clearly shown on the cuffs 110 and 120 so that the medical staff can attach the cuffs 110 and 120 so that the electrodes have such a positional relationship when the cuffs 110 and 120 are attached. It is good to keep.

  Further, in the above-described embodiment, the case where the cuff 110 is attached to the left arm and the cuff 120 is attached to the right foot has been described, but the cuff 110 is attached to the right arm and The cuff 120 may be worn on the left foot. In short, one cuff 110 may be attached to the upper limb of the subject and the other cuff 120 may be attached to the lower limb of the subject. In other words, the cuffs 110 and 120 may be mounted at positions where the current passes through the heart 200 when a current is passed through the cuff 110 and the cuff 120 via the human body.

  Furthermore, the configuration using the resonance circuit shown in FIG. 1 and FIGS. 9 to 13 is not limited to the case of measuring PWV, but can be widely applied to devices that measure biological information based on impedance fluctuations. In that case, the position where the cuff is worn does not necessarily have to be the upper limb and the lower limb.

  Further, in the above-described embodiment, the case where the electrodes for measuring the impedance are provided in the cuffs 110 and 120 (20, 30), respectively, but only one electrode for measuring the impedance is provided in the cuff and the other is provided. The electrode may be attached to the subject without being provided on the cuff. For example, in FIG. 2, as described in the embodiment, the electrode 121 is provided on the cuff 120 and attached to the subject with the cuff 120 on the lower limb, whereas the electrode 111 is not provided on the cuff 110. It is attached to the head, neck, upper limb, etc. of the body regardless of the cuff 110. The electrode 111 may be attached to the subject using, for example, an adhesive tape or the like, as in the conventional case, and attached to the subject's body surface. The position where the electrode 111 is attached may be a position where the current passes through the heart 200 when a current is passed between the electrode 121 and the electrode 111 via the human body. In other words, the electrode 111 may be attached so that the electrode 121 and the electrode 111 are disposed at a position sandwiching the heart 200.

  Thus, when one electrode is not provided in the cuff, there is an advantage that the degree of freedom of mounting is increased as compared with the case where both electrodes are provided in the cuff.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

  The present invention can be applied to a biological information measuring device that measures biological information using electrodes.

10, 100 Biological information measuring device 20, 30, 110, 120 Cuff 21, 22, 31, 32, 111, 121 Electrode 40 Human body 50, 51, 300 Coil 60, 141 High frequency constant current power supply 70 Detection unit 112 Arm band 113, 123 Air bag 122 Foot band 130 Blood pressure pulse wave measurement unit 140 Impedance pulse wave measurement unit 150 Electrocardiogram measurement unit 160 Control / calculation unit 200 Heart

Claims (12)

A first electrode comprising at least one electrode;
A second electrode comprising at least one electrode;
A cuff for accommodating the first electrode in a belt such that at least a portion of the first electrode is not exposed;
When the first and second electrodes are regarded as a capacitor using a human body of the subject and other substances electrically sandwiched by the first and second electrodes as a capacitor, the capacitor is included. A resonant circuit,
A current supply for supplying a high-frequency constant current to the first and second electrodes;
A detector that detects an impedance variation based on a voltage change of the first and second electrodes, and detects biological information based on the impedance variation;
A biological information measuring device. With the first cuff,
The second cuff,
An electrode that is provided in each of the first cuff and the second cuff, and at least a part of which is accommodated in the belts of the first and second cuffs and not exposed to the cuff surface;
When the electrodes of the first and second cuffs are regarded as capacitors having a human body of a subject and other substances electrically sandwiched by the electrodes of the first and second cuffs as dielectrics, A resonant circuit including a capacitor;
A current supply for supplying a high frequency constant current to the electrodes of the first cuff and the second cuff;
A detecting unit that detects impedance fluctuation based on a voltage change of the electrodes of the first cuff and the second cuff, and detects biological information based on the impedance fluctuation;
A biological information measuring device. The resonance frequency of the resonance circuit matches the frequency of the high-frequency constant current.
The biological information measuring device according to claim 1 or 2. The first electrode and the second electrode are respectively
A supply electrode for supplying the high-frequency constant current to the subject;
A detection electrode for detecting the voltage change ;
The biological information measuring device according to claim 1, comprising: The electrodes of the first cuff and the second cuff are respectively
A supply electrode for supplying the high-frequency constant current to the subject;
A detection electrode for detecting the voltage change ;
The biological information measuring device according to claim 2, comprising: The supply electrode is accommodated in the belt and is not exposed on the belt surface,
The detection electrode is not accommodated in the belt and is exposed on the belt surface,
The biological information measuring device according to claim 5 . The electrode is planar.
The biological information measuring device according to any one of claims 1 to 6. The detection unit detects a state of a pulse wave or a breath as the biological information.
The biological information measuring device according to any one of claims 1 to 7. Having an electrocardiogram measurement unit for measuring an electrocardiogram using the detection electrode;
The biological information measuring device according to claim 4 or 5. Having a blood pressure measurement unit for measuring blood pressure using the cuff;
The biological information measuring device according to claim 2, 5 or 6 . A bag-like belt wrapped around the upper or lower limbs;
An air bag provided in the belt;
A planar electrode that is at least partially contained within the belt and not exposed to the belt surface;
Have
The planar electrode is
A supply electrode for supplying current to the subject for measuring biological information;
A detection electrode for detecting the voltage of the subject;
Have
The supply electrode is accommodated in the belt and is not exposed on the belt surface,
The detection electrode is not accommodated in the belt and is exposed on the belt surface,
Cuff for measuring biological information. A bag-like belt wrapped around the upper or lower limbs;
An air bag provided in the belt;
A planar electrode that is at least partially contained within the belt and not exposed to the belt surface;
Have
At least a portion of the air bag is formed of a conductive material, and the air bag functions as the planar electrode;
Raw body information cuff.

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