JP2016036488A - Pulse wave measurement device and biological information measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse wave measurement device capable of measuring a pulse wave preferable for PWV measurement.SOLUTION: A high frequency current is supplied to electrodes 101 and 121 attached to a subject's neck or head, and lower extremity by a high frequency current supply circuit 140, a magnetic field generated from the aorta then is detected by a magnetic sensor 102, and a pulse wave of the aorta is acquired based on the detected magnetism so that the aorta pulse wave can be detected by the magnetic field accurately. By measuring the PWV using the aorta pulse wave, the accurate PWV can be detected.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pulse wave measurement device and a biological information measurement device.

  In recent years, with the increasing aging society, early diagnosis and treatment of early treatment of arteriosclerotic diseases are urgently needed. As one method for quantitatively diagnosing arteriosclerosis in a non-invasive manner, an aortic pulse wave velocity test method for measuring a pulse wave velocity (PWV) between two points of the aorta is known.

  The aortic pulse wave velocity inspection method uses the property that the pulse wave velocity is fast in a hard substance and slow in a soft substance. In the aortic pulse wave velocity inspection method, first, the time required for the pulse wave to propagate between two points of the aorta in the same direction as viewed from the heart is measured, and then the measured time and the distance between the two points (arterial length). ) To calculate the pulse wave velocity. From the fact that the healthy arterial wall is soft and rich and the arteriosclerotic blood vessel wall is hard and brittle, it is diagnosed that the higher the measured pulse wave velocity, the more the arteriosclerosis is progressing.

  The types of PWV include cfPWV (carotid-femoral PWV: carotid-femoral PWV) (for example, see Non-Patent Document 1) and baPWV (brachial-ankle PWV: upper arm-ankle PWV) (for example, non-patent literature). 2), hcPWV (heart-carotid PWV).

  Furthermore, as an index of the degree of arteriosclerosis using PWV, there is CAVI (Cardio-Ankle Vascular Index) (for example, see Non-Patent Document 3). CAVI measures blood pressure and pulse wave by wearing a cuff on the upper arm and ankle (or popliteal area), and measures heart sound by wearing a heart sound microphone on the sternum.

Yoshiaki Masuda, Hiroshi Kanai, “Fundamental and Clinical Arterial Pulse Waves”, Kyoritsu Shuppan, 15-19 pages, 2000 Toshio Ozawa, Yoshiaki Masuda, "Pulse wave velocity", Medical View, 28-29 pages Kohji Shirai, Junji Utino, Kuniaki Ohtsuka, Masanobu Takada, "A Novel Blood Pressure-independent Arterial Wall Stiffness Parameter; Cardio-Ankle Vascular Index (CAVI)", Journal of Atherosclerosis and Thrombosis, Vol.13, No.2

  By the way, in the conventional cfPWV, the starting point for measuring PWV is the carotid artery and the end point is the groin of the femoral artery, and in baPWV, the starting point is the upper arm and the end point is the ankle. In the PWV measurement, it is ideal to place the starting point on the upstream side and the end point on the downstream side as viewed from the blood flow (in other words, in the propagation direction of the pulse). However, both cfPWV and baPWV are not preferable because the starting point and the ending point are set on an artery where blood ejected from the heart branches in different directions. The reason why the starting point and the ending point have to be set at such positions is that the position where the arterial pulse wave can be taken is actually limited to the position where the artery is close to the body surface.

  In addition, hcPWV uses elements that are difficult to measure, such as heart sounds and notch portions of arteries, which may reduce accuracy.

  The present invention has been made in consideration of the above points, and a pulse wave measuring device capable of measuring a pulse wave preferable for PWV measurement, and obtaining biological information such as PWV with high accuracy using the pulse wave. Provides a biological information measuring device.

One aspect of the pulse wave measuring device of the present invention is:
A first electrode attached to the first part of the subject;
A second electrode attached to the second part of the subject;
A high-frequency current supply unit for supplying a high-frequency current to the first and second electrodes;
A magnetic field detector provided near the body surface between the first electrode and the second electrode in the subject and detecting a magnetic field generated from an artery when the high-frequency current is supplied;
Based on the magnetism detected by the magnetic field detection unit, a pulse wave measurement unit for obtaining a pulse wave of the artery,
It comprises.

One aspect of the biological information measuring device of the present invention is:
The pulse wave measuring device;
A peripheral arterial pulse wave measurement unit for measuring a peripheral arterial pulse wave of a subject far from the heart than a measurement point by the pulse wave measuring device;
The first timing at which blood is ejected from the heart is detected based on the aortic pulse wave obtained by the pulse wave measuring device, and the peripheral artery pulse wave is obtained based on the peripheral arterial pulse wave obtained by the peripheral arterial pulse wave measuring unit. A calculation unit that detects a second timing at which the pulse arrives at a site where the arterial pulse wave measurement unit is mounted, and calculates a pulse wave propagation time from a difference between the second timing and the first timing;
It comprises.

One aspect of the biological information measuring device of the present invention is:
The pulse wave measuring device;
A peripheral arterial pulse wave measurement unit for measuring a peripheral arterial pulse wave of a subject far from the heart than a measurement point by the pulse wave measuring device;
The first timing based on the pulse wave obtained by the pulse wave measurement device is detected, and the peripheral artery pulse wave measurement unit is mounted based on the peripheral artery pulse wave obtained by the peripheral artery pulse wave measurement unit. Calculating a pulse wave propagation time from a difference between the second timing and the first timing;
It comprises.

One aspect of the biological information measuring device of the present invention is:
Having the pulse wave measuring device,
As the magnetic field detection unit, a first magnetic field detection unit provided near the body surface between the first electrode and the second electrode in the subject, the first electrode and the second in the subject A second magnetic field detection unit provided near the body surface between the electrodes and provided downstream of the first magnetic field detection unit when the high-frequency current is supplied;
Further, the pulse wave propagation time is calculated from the first arterial pulse wave timing based on the detection result of the first magnetic field detection unit and the second arterial pulse wave timing based on the detection result of the second magnetic field detection unit. It has a calculation part to calculate.

  According to the present invention, a high frequency current is supplied to a subject, a magnetic field generated by a current flowing through the artery at that time is detected by the magnetic field detection unit, and a pulse wave of the artery is detected based on the detected magnetic field. For example, a pulse wave of an artery far from the body surface such as an aorta can be detected.

  As a result, for example, the timing at which the aortic valve is opened and the blood is actually ejected from the heart is detected by the magnetic field, so that the aortic pulse wave can be detected noninvasively with high accuracy. Therefore, an accurate pulse wave velocity can be obtained by obtaining a pulse wave velocity using the blood ejection timing from the heart based on this aortic pulse wave.

  Also, for example, if the magnetic field detector detects the magnetic field at any two points in the artery, detects the arterial pulse waves at the two points, and calculates the pulse wave propagation time based on the two arterial pulse waves Thus, the PWV between any two points can be obtained with high accuracy.

Diagram for explaining the principle of the embodiment Diagram showing the right-hand rule 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 aortic pulse wave and pressure pulse wave Diagram for explaining the propagation time of pulse wave from aortic pulse wave and pressure pulse wave The figure which shows the structural example of a magnetic field detection part The figure which shows the structural example of a magnetic field detection part The figure which shows the structural example of a magnetic field detection part The figure which shows the structure of the Rogowski coil by embodiment The figure which serves for description of Embodiment 2 The figure which serves for description of Embodiment 2

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

<Principle>
First, before describing a specific configuration of the embodiment, the principle of the present embodiment will be described with reference to FIG.

  As the heart contracts, the aorta swells with the ejected blood. When the aorta is inflated, the electrical resistance of the aorta decreases. When an electrode is attached to the neck or head and lower limbs of a human body and a high-frequency current is applied, the current flows more in a portion having a low resistance in the body. Since blood has a low electrical resistance compared to other elements of the body, current flows primarily along the aorta. Therefore, the value of current flowing from the neck or head to the lower limb greatly depends on the amount of blood in the aorta. That is, every time blood is ejected into the aorta, the current flowing through the aorta changes. Due to the current flowing through the aorta, as shown in FIG. 2, a magnetic field is generated around by the right-hand rule, and the strength of the magnetic field changes whenever blood is ejected.

  In the present invention, the change of the magnetic field is detected by a magnetic field detection unit arranged outside the body to obtain an aortic pulse wave, and the opening time of the aortic valve (blood ejection timing) is detected from the aortic pulse wave. The pulse wave propagation time can be measured by measuring the pulse wave arrival time from this aortic valve opening time to another pulse wave detection site, and the PWV is obtained using the pulse wave propagation time.

  As another PWV measurement method, in the present invention, magnetic field detectors are arranged at two locations, an upstream position and a downstream position in a section in which a high-frequency current flows, so that the magnetic field detector detects magnetic fields at two arbitrary points in the artery. Then, the two arterial pulse waves are detected, and the pulse wave propagation time is calculated based on the two arterial pulse waves. As a result, the PWV between any two points can be obtained with high accuracy.

<Embodiment 1>
FIG. 3 is a schematic diagram showing the overall configuration of a biological information measuring device equipped with the pulse wave measuring device 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, a high-frequency current supply circuit 140, a magnetic detection / pulse wave measurement unit 150, an electrocardiogram measurement unit 160, a control / calculation unit 170, a storage unit 181, an input unit 182, A display unit 183, an audio unit 184, and a printing unit 185 are provided.

  The control / arithmetic unit 170 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 181 is a storage device such as a hard disk, and stores measurement results and the like under the control of the control / calculation unit 170. The input unit 182 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 170. The control / calculation unit 170 performs control and calculation according to the operation signal. The display unit 183 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 170. Note that the display unit 183 may be configured by a touch panel and may have an input function in addition to the display function. The voice unit 184 is a speaker device, and outputs operation guidance or an alarm sound according to the control of the control / calculation unit 170. The printing unit 185 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 170.

  The blood pressure pulse wave measurement unit 130 measures the pulse wave and blood pressure of the peripheral artery of the subject. 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 for pulse wave measurement and blood pressure measurement, and can be set individually.

  In the case of this embodiment, the measurement of the peripheral arterial pulse wave and the measurement of the aortic pulse wave are performed simultaneously.

  The peripheral arterial pulse wave can be measured 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, blood pressure is measured using the first cuff 110, that is, the upper arm cuff, and the peripheral arterial pulse wave is measured using the second cuff 120.

  When measuring the peripheral artery pulse wave, the blood pressure pulse wave measurement unit 130 first pressurizes the cuff 120 until the cuff pressure reaches a predetermined value. 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 peripheral arterial pulse wave signal, and outputs the detected peripheral arterial pulse wave signal to the control / calculation unit 170.

  On the other hand, in the case of blood pressure measurement, the blood pressure pulse wave measurement unit 130 pressurizes the cuff 110 to a predetermined value that would stop the blood, and then detects vibrations of the cuff 110 during the decompression using the pressure sensor. The cuff pressure at the time when the amplitude starts to increase is detected as the systolic blood pressure, and the cuff pressure at which the vibration decrease is most significant 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 170.

  The electrocardiogram measurement unit 160 is connected to electrodes 111 and 121 provided on the surfaces of the cuffs 110 and 120 that are in contact with the body surface. The electrocardiogram measurement unit 160 has 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 160 outputs the detection signal after the signal processing to the control / calculation unit 170 as an electrocardiogram signal.

  The high-frequency current supply circuit 140 supplies a high-frequency current to the electrode 101 attached to the subject's neck or head and the electrode 121 of the second cuff 120. As a result, a high frequency current flows between the neck or head of the subject and the lower limbs. In the present embodiment, the first electrode 101 is provided on the neck or the head and the second electrode 121 is provided on the ankle among the electrodes for supplying a high-frequency current. The second electrode is shown in FIG. As such, it may be provided on the thigh. In short, the first electrode and the second electrode may be provided at a position where the main route through which the high-frequency current flows passes through the aortic root. For example, the first electrode may be provided on the upper arm. That is, a high frequency current may be supplied via the electrode 111 of the first cuff 110. However, it is preferable to provide electrodes on the neck and head because a large current flows through the aorta as a result.

  The frequency of the high-frequency current supplied by the high-frequency current supply unit 140 is on the order of several kHz to 100 kHz. In this embodiment, a high frequency current of about 1 mA is supplied at around 50 kHz. The current value to be supplied may be set according to the sensitivity of the magnetic sensor 102 or the like.

  Here, the frequency of the high-frequency current supplied to the electrodes 101 and 121 is on the order of several kHz to 100 kHz, while the electrocardiogram component is at most about 100 Hz, and the frequency band is greatly separated. Therefore, even if the electrocardiogram measurement and the high-frequency current are simultaneously performed, the electrocardiogram measurement is not adversely affected.

  The magnetic detection / pulse wave measurement unit 150 obtains an aortic pulse wave signal based on the detection result detected by the magnetic sensor 102. Specifically, the magnetic sensor 102 is provided near the body surface of the subject, and when a current flows through the aorta, as shown in FIG. 2, a magnetic field generated by the right-handed screw law is generated. An electric signal corresponding to the detected magnitude of the magnetic field is output to the magnetic detection / pulse wave measuring unit 150. The magnetic detection / pulse wave measurement unit 150 obtains an aortic pulse wave signal by extracting a component having a heartbeat-synchronous component as a fundamental wave from the input electrical signal by detection.

  As described above, the electrical resistance in the path through the aorta varies depending on the blood volume of the aorta, and decreases as the blood volume increases. Therefore, immediately after the opening of the aortic valve, an aortic pulsating flow occurs, the blood volume increases, and the electrical resistance decreases. The aortic pulse wave obtained by the magnetic detection / pulse wave measuring unit 150 is a pulse wave that varies with the pulsatile flow from such an aortic valve. By observing the aortic pulse wave, the timing at which blood is ejected from the aortic valve can be detected. If the ejection timing of blood from the heart is detected using this aortic pulse wave, the ejection timing of blood 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.

  Next, a method for calculating PWV using the aortic pulse wave and the peripheral arterial pulse wave will be described with reference to FIGS.

  In calculating the PWV, the control / arithmetic unit 170 executes a processing procedure shown in FIG. When the control / calculation unit 170 starts the PWV calculation process in step S <b> 0, the control / calculation unit 170 sets the cuff pressures of the cuffs 110 and 120 to be pressurized by the blood pressure pulse wave measurement unit 130 in step S <b> 1. In step S2, the aortic pulse wave measured by the magnetic detection / pulse wave measuring unit 150 is read, and in step S3, the peripheral arterial pulse wave measured by the blood pressure pulse wave measuring unit 130 is read.

  FIG. 5 shows the state of the aortic pulse wave and the peripheral arterial pulse wave read in steps S2 and S3. In FIG. 5, the time axes of the aortic pulse wave and the peripheral arterial pulse wave are shown in accordance with the same time axis.

  In step S4, the control / calculation unit 170 detects a change point (that is, a rising point) at which the aortic pulse wave increases and a change point (that is, a rising point) at which the pressure of the peripheral artery pulse wave increases. In detecting the change point, for example, a differential method or the like can be used. In the example of FIG. 5, the aortic pulse wave has the above-mentioned changing point at the time point t1, and the peripheral arterial pulse wave has the above-mentioned changing point at the time t2.

  In step S5, the control / calculation unit 170 calculates the pulse wave propagation time T from the heart 200 to the attachment site of the second cuff 120 by calculating t2-t1. Next, in step S <b> 6, the control / calculation unit 170 calculates P / VV by calculating T / L using a preset distance L from the heart 200 to the attachment site of the second cuff 120.

  As described above, according to the present embodiment, the high-frequency current is supplied to the electrodes 101 and 121 attached to the subject's neck or head and the lower limbs by the high-frequency current supply circuit 140, and then By detecting the magnetic field generated from the aorta by the magnetic sensor 102 and obtaining the aortic pulse wave based on the detected magnetism, the timing when the aortic valve is opened and the blood is actually ejected from the heart is detected by the magnetic field. It can be detected with high accuracy. Therefore, the PWV can be detected with high accuracy by measuring the PWV using this ejection timing.

  Moreover, since the biological information measuring apparatus 100 of this embodiment has the electrocardiogram measuring unit 160, when the level of the aortic pulse wave measured by the magnetic detection / pulse wave measuring unit 150 is small, the electrocardiogram is used as a reference. Thus, it becomes possible to narrow down the position where the change point in the aortic pulse wave is to be detected (that is, to set the target range).

  In the present invention, it is important to increase the detection sensitivity of the magnetic field in order to obtain an accurate PWV. Hereinafter, a configuration for increasing the magnetic field detection sensitivity will be described.

  In FIG. 6, a magnetic belt 300 is used as the magnetic field detector. The magnetic belt 300 is arranged so as to go around the human torso. More specifically, the magnetic belt 300 is disposed so as to go around the trunk in a direction in which the human body is cut into a circle. In this embodiment, since the ejection timing of blood from the aortic valve is detected, the magnetic belt 300 is arranged so as to go around the chest close to the aortic valve (starting portion of the aorta). The magnetic belt 300 is formed of a material in which a magnetic field easily passes through the material (that is, the magnetic resistance is low), but an eddy current is not easily generated in the material (a current does not easily flow). In particular, it is formed of a material through which a magnetic field having a high frequency current supplied to the electrodes 101 and 121 easily passes. In the present embodiment, since a high frequency current of about 50 kHz is supplied, the magnetic field generated from the aorta is also about 50 kHz. In order to collect this magnetic field, the magnetic belt 300 can easily pass a magnetic field of about 50 kHz. It is configured. Such a magnetic belt 300 can be manufactured, for example, by kneading iron oxide powder into rubber.

  A magnetic sensor 301 is provided in part of the circumferential direction of the magnetic belt 300. The magnetic field collected by the magnetic belt 300 is detected by the magnetic sensor 301. A lead wire 302 is derived from the magnetic sensor 301, and a detection result by the magnetic sensor 301 is output to the magnetic detection / pulse wave measuring unit 150 via the lead wire 302.

  By providing the magnetic belt 300, the magnetic field generated by the high-frequency current flowing in the aorta can be efficiently collected on the magnetic belt 300, so that the detection sensitivity of the magnetic field can be increased.

  FIG. 7 shows an example in which the magnetic field detection unit has a current transformer configuration. By winding the coil 303 around the magnetic belt 300, the electric field collected by the magnetic belt 300 can be detected by the coil 303.

  FIG. 8 shows an example in which a Rogowski coil 400 is used as the magnetic field detector. The Rogowski coil 400 is arranged so as to circulate around the human torso, and a voltage generated from the Rogowski coil 400 when the magnetic field generated by the high-frequency current flowing in the aorta circulates in the Rogowski coil 400 is detected. It can be set as the structure which raises a detection sensitivity. In FIG. 8, the Rogowski coil 400 is shown in a simplified manner, but the Rogowski coil 400 of the present embodiment is configured as shown in FIG. The Rogowski coil 400 includes a magnetic core 401 that is partially divided (notched) in the circumferential direction, a winding 402 that winds the magnetic core 401, and a rewind wire 403. By providing the magnetic core 401 in this way, the magnetic field detection sensitivity can be increased.

  Since the Rogowski coil 400 is partly cut (notched) in the circumferential direction, it can be easily attached to the body by widening the notched portion. There is an advantage that you can. Also in the case of the magnetic belt 300, if it is configured such that a notch is partially provided and the notch can be widened, it can be easily attached to the body. If a fastener made of the same material as that of the magnetic belt 300 is disposed in the notched portion and the fastener is stopped after the mounting is completed, it is possible to prevent a decrease in magnetic field collecting ability due to the notch.

  Incidentally, when the magnetic field is detected using the magnetic field collecting means that collects the magnetic field around the aorta as in the above-described embodiment, the high-frequency current to be supplied is preferably a constant-frequency high-frequency current. On the other hand, when a magnetic field is detected only with one body surface closest to the aorta, the supplied high-frequency current may be a constant-voltage high-frequency current or a constant-current high-frequency current.

  In the above-described embodiment, the case where the cuffs 110 and 120 are used as the peripheral arterial pulse wave measuring unit for measuring the peripheral arterial pulse wave has been described. However, the present invention is not limited thereto, and the peripheral arterial pulse wave is measured. You may perform a measurement using things other than a cuff. The peripheral arterial pulse wave can be measured by, for example, a tonometry method, a photoelectric pulse wave method, a strain sensor method, an ultrasonic method, or the like.

  In the above-described embodiment, the case where the timing at which blood is ejected from the heart is detected using the magnetic field detection unit (for example, the magnetic belt 300) has been described. The detection using this is not limited to the timing at which blood is ejected from the heart. For example, a magnetic belt 300 that is a magnetic field detector is attached to the thigh, a cuff that is a peripheral artery pulse wave measurement unit is attached to the ankle, the first timing is obtained from the pulse wave of the thigh, and the pulse of the ankle is obtained. If the second timing is obtained from the wave and the difference between the second timing and the first timing is obtained, the pulse wave propagation time between the thigh and the ankle can be obtained.

<Embodiment 2>
In the first embodiment described above, the first timing at which blood is ejected from the heart is detected based on the aortic pulse wave obtained by the magnetic field detection unit (for example, the magnetic belt 300), and the peripheral arterial pulse wave measurement unit ( For example, based on the peripheral arterial pulse wave obtained by the cuff 120), the second timing at which the pulse arrives at the site where the peripheral arterial pulse wave measuring unit is mounted is detected, and the difference between the second timing and the first timing is detected. The pulse wave propagation time was calculated, and PWV was calculated based on it.

  In the present embodiment, as shown in FIG. 10, two magnetic field detectors are provided between two electrodes that supply a high-frequency current, and the first obtained based on the detection result of the first magnetic field detector. The pulse wave propagation time is calculated from the second arterial pulse wave and the second arterial pulse wave obtained based on the detection result of the second magnetic field detector, and the PWV is calculated based on the pulse wave propagation time. In the case of FIG. 10, a magnetic belt 310 and a magnetic belt 320 are provided between two electrodes. The magnetic field collected by the magnetic belt 310 is output to the magnetic detection / pulse wave measuring unit 150 via the magnetic sensor 311 and the lead wire 312, and the magnetic field collected by the magnetic belt 320 is output from the magnetic sensor 321 and the lead wire. It is output to the magnetic detection / pulse wave measurement unit 150 via 322.

  The magnetic detection / pulse wave measurement unit 150 calculates the pulse wave propagation time from the difference between the rise time of the arterial pulse wave obtained by the magnetic belt 310 and the rise time of the arterial pulse wave obtained by the magnetic belt 320. And calculate PWV. Since this PWV is a PWV between an arterial position corresponding to a place where the magnetic belt 310 is attached and an arterial position corresponding to a place where the magnetic belt 320 is attached, it exists between those arterial positions. It can be used as an index of arteriosclerosis of arteries.

  Of course, the interval for calculating the PWV is not limited to the interval in FIG. For example, as shown in FIG. 11, if the first magnetic belt 310 is attached to the abdomen and the second magnetic belt 320 is attached to the thigh, the PWV of the artery during that time can be measured.

  As described above, according to the present embodiment, the magnetic field detector detects the magnetic field at any two points of the artery, detects the arterial pulse waves at the two points, and based on the arterial pulse waves at the two points, the pulse is detected. By calculating the wave propagation time, the PWV between any two points can be obtained with high accuracy. In particular, the present invention can detect a pulse wave of an artery at a position away from the body surface, which has been difficult to measure in the past, so that the selection range of the artery capable of measuring PWV is dramatically expanded.

  Incidentally, the position where the magnetic field detection units such as the magnetic belts 300, 310, and 320 are provided may be a position that directly touches the body surface (bare skin) or a position where clothing is interposed between the body surface. In short, the magnetic field detector may be provided in the vicinity of the body surface so that a magnetic field generated from the human body can be detected when a high-frequency current is passed. Similarly, an electrode for supplying a high-frequency current may be provided at a position where the electrode directly touches the body surface (skin), or may be provided at a position where a substance such as a cloth is interposed between the electrode and the body surface. In short, the electrode for supplying the high-frequency current may be attached in a state that allows a desired value of high-frequency current to flow through the human body.

  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 main features thereof.

  The present invention can be applied to a biological information measuring device that measures biological information such as a pulse wave velocity.

DESCRIPTION OF SYMBOLS 100 Biological information measuring device 101, 111, 121 Electrode 102, 301, 311, 321 Magnetic sensor 110, 120 Cuff 130 Blood pressure pulse wave measurement part 140 High frequency current supply circuit 150 Magnetic detection and pulse wave measurement part 160 Electrocardiogram measurement part 170 Control / Arithmetic unit 200 Heart 300, 310, 320 Magnetic belt 400 Rogowski coil

Claims (10)

A first electrode attached to the first part of the subject;
A second electrode attached to the second part of the subject;
A high-frequency current supply unit for supplying a high-frequency current to the first and second electrodes;
A magnetic field detector provided near the body surface between the first electrode and the second electrode in the subject and detecting a magnetic field generated from an artery when the high-frequency current is supplied;
Based on the magnetism detected by the magnetic field detection unit, a pulse wave measurement unit for obtaining a pulse wave of the artery,
A pulse wave measuring apparatus comprising: The first electrode is attached to the neck or head of the subject,
The second electrode is attached to a lower limb of the subject.
The pulse wave measuring device according to claim 1. The magnetic field detector is
Provided on the chest of the subject;
The pulse wave measuring device according to claim 1 or 2. The magnetic field detector is
A magnetic belt that is provided to circulate in a direction to cut the human body of the subject, and that collects a magnetic field;
A magnetic sensor for detecting a magnetic field collected by the magnetic belt;
Having
The pulse wave measuring device according to any one of claims 1 to 3. The magnetic field detector is
It is provided so as to go around the torso of the subject's human body, and has a Rogowski coil with a magnetic body as a core,
The pulse wave measuring device according to any one of claims 1 to 3. The magnetic field detector is
A magnetic belt that is provided to circulate in a direction to cut the human body of the subject, and that collects a magnetic field;
A coil for winding the magnetic belt;
Comprising a current transformer configuration having
The pulse wave measuring device according to any one of claims 1 to 3. The magnetic field detector is
A first magnetic field detector provided in the vicinity of the body surface between the first electrode and the second electrode in the subject;
A second surface provided near the body surface between the first electrode and the second electrode in the subject and provided downstream of the first magnetic field detector when the high-frequency current is supplied. The magnetic field detector of
The pulse wave measuring device according to any one of claims 1 to 6. The pulse wave measuring device according to any one of claims 1 to 6,
A peripheral arterial pulse wave measurement unit for measuring a peripheral arterial pulse wave of a subject far from the heart than a measurement point by the pulse wave measuring device;
The first timing at which blood is ejected from the heart is detected based on the aortic pulse wave obtained by the pulse wave measuring device, and the peripheral artery pulse wave is obtained based on the peripheral arterial pulse wave obtained by the peripheral arterial pulse wave measuring unit. A calculation unit that detects a second timing at which the pulse arrives at a site where the arterial pulse wave measurement unit is mounted, and calculates a pulse wave propagation time from a difference between the second timing and the first timing;
A biological information measuring device comprising: The pulse wave measuring device according to any one of claims 1 to 6,
A peripheral arterial pulse wave measurement unit for measuring a peripheral arterial pulse wave of a subject far from the heart than a measurement point by the pulse wave measuring device;
The first timing based on the pulse wave obtained by the pulse wave measurement device is detected, and the peripheral artery pulse wave measurement unit is mounted based on the peripheral artery pulse wave obtained by the peripheral artery pulse wave measurement unit. Calculating a pulse wave propagation time from a difference between the second timing and the first timing;
A biological information measuring device comprising: The pulse wave measuring device according to claim 7,
From the first arterial pulse wave obtained based on the detection result of the first magnetic field detection unit and the second arterial pulse wave obtained based on the detection result of the second magnetic field detection unit, the pulse An arithmetic unit for calculating the wave propagation time;
A biological information measuring device comprising:

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