JP2010207274A - Pulse wave measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optimal volume pulse wave output at an optimal relative position between an artery and a photoelectric element. <P>SOLUTION: A pulse wave measuring apparatus 10 has an LED element 102 and a PD element 103 disposed at predetermined intervals, and measures a pulse wave on the basis of an electric signal outputted by a PD element 103. The pulse wave measuring apparatus 10 has: an ultrasonic transmission/reception element 114 for transmitting/receiving ultrasound, converting the received ultrasound into an electric signal and outputting it; and an output device 116 (speaker) for outputting the electric signal outputted by the ultrasonic transmission/reception element 114. In order to provide the LED element 102 and the PD (photodiode) element 103 at an optimal position with respect to the artery of a human, a transmission/reception port for transmitting/receiving ultrasound by the ultrasonic transmission/reception element 114 is placed on a second axis orthogonal to a first axis through an intermediate position of the first axis combining the LED element 102 and the PD element 103. A user is allowed to know an optimal measurement position while monitoring sound output from a speaker. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pulse wave measuring apparatus, and more particularly to a pulse wave measuring apparatus that measures a pulse wave based on an electric signal obtained by converting light emitted from a light emitting element and received by a light receiving element.

  For example, Patent Document 1 discloses a portable sphygmomanometer that is worn on one arm of a subject and constantly measures blood pressure during daily life. The portable sphygmomanometer of Patent Document 1 measures a cardiac radio wave and a volume pulse wave, calculates a volume pulse wave transmission time, calculates a maximum value and a minimum value of blood pressure, and has one electrode in contact with the surface of a living body. A cardiac radio wave detection means and a volume pulse wave detection means having a photoelectric sensor in contact with the surface of the living body are provided. The electrocardiogram detection means detects the electrocardiogram using the electrocardiogram induced by one electrode as a potential with respect to the ground of the electrocardiogram detection means, and the volume pulse wave detection means uses a photoelectric sensor in contact with the surface of the living body. The wave is measured, the pulse wave transmission time is obtained from the time difference between the cardiac radio wave R wave and the pulse wave peak, and the blood pressure is calculated based on a predetermined correlation table between the pulse wave transmission time and the blood pressure.

  Patent Document 2 discloses an ultrasonic blood flow meter for measuring systolic blood pressure using ultrasonic waves. This ultrasonic blood flow meter is an ultrasonic probe that irradiates blood vessels with ultrasonic waves and converts blood flow into blood flow signals, and processing that outputs the converted blood flow signals as audio signals or displays them as blood flow rates A blood flow meter main body having a function and a cuff connected to the blood flow main body. The blood flow meter body has a built-in pump for pressure increase / decrease to the cuff and a pressure sensor for measuring the cuff pressure. The blood pressure signal obtained immediately after the cuff pressure is reduced is displayed on the LCD. To do.

  Further, Patent Document 3 discloses a blood pressure measuring device and method for measuring blood pressure without using a cuff. This blood pressure measurement device has a measurement unit that measures the blood flow velocity of a living body and a measurement unit that measures volume pulse waves. Then, the blood flow volume and vascular resistance are calculated from the information obtained from the blood flow velocity measurement unit and the volume pulse wave measurement unit, and the blood pressure is measured.

JP 2004-81285 A JP-A-6-125903 JP 2004-152431 A

For example, in a pulse wave measuring device that measures a pulse wave using a photoelectric element composed of an LED (light emitting diode) element and a PD (photodiode) element, light emitted from the LED element is irradiated onto a human artery, and the reflected light is irradiated. Is received by a PD element and converted into an electrical signal, and based on the electrical signal, heart rate as well as blood vessel age, arteriosclerosis, oxygen saturation, blood pressure, and the like can be measured.
However, for example, in order to obtain a precise waveform of an electric signal that can be estimated as a so-called blood vessel age and that has less noise, it is necessary to mount the photoelectric element at an optimal position in consideration of the position of a human artery.

  On the other hand, the sphygmomanometer of Patent Document 1 can detect a pulsation component even if a photoelectric element position shift occurs about 1 cm to 2 cm with respect to an artery. However, it is difficult to position the photoelectric element at the optimal position to obtain a precise waveform with little noise, and even if the optimal position is obtained at the time of wearing, it may shift at the time of wearing with a wearing method such as a watch band, In addition, it is very difficult to mount with one hand operation without shifting the mounting position. On the other hand, it is difficult to control because it is manual in order to obtain an optimum measurement pressure for obtaining a clean waveform with a precise and low noise.

Moreover, although the ultrasonic blood flow meter of patent document 2 is equipped with the probe which converts into a blood-flow signal using an ultrasonic wave and a pressure-reducing pump as a means to obtain a blood-flow signal, The stop of the flow signal or the resumption of blood flow is detected, and the blood pressure is only obtained from the air bag pressure waveform.
Furthermore, the blood pressure measurement device and method of Patent Document 3 measure blood flow signals with ultrasonic waves and measure volume pulse waves with photoelectric elements. Ultrasonic waves are used to measure blood flow velocity as an aid to blood pressure measurement. It is estimated that it is difficult to improve the accuracy of the blood pressure measurement algorithm by using information from arteries located in a living body and using information from a photoelectric element in a binary manner.

  The present invention has been made in view of the circumstances as described above, and provides a pulse wave measuring device capable of obtaining a more optimal volume pulse wave output at an optimal relative position between an artery and a photoelectric element. It is the purpose.

  In order to solve the above-mentioned problem, a first technical means of the present invention includes a light emitting element and a light receiving element arranged at predetermined intervals, and converts the light emitted from the light emitting element and received by the light receiving element. In a pulse wave measuring device that measures a pulse wave based on a signal, an ultrasonic transmitter / receiver that transmits / receives an ultrasonic wave, converts the received ultrasonic wave into an electric signal and outputs the electric signal, and an electric signal output from the ultrasonic wave transmitter / receiver And a transmission / reception port for transmitting / receiving ultrasonic waves by the ultrasonic transmitter / receiver, passing through an intermediate position of the first axis connecting the light emitting element and the light receiving element, and orthogonal to the first axis It is characterized by being arranged on the second axis.

  According to a second technical means, in the first technical means, the output means is an audio output means for outputting an electric signal output from the ultrasonic transceiver.

  According to the present invention, it is possible to easily perform the optimum measurement pressurization at the optimum relative position between the artery and the photoelectric element, and to obtain a more optimum volume pulse wave output.

1 is an external perspective view of an embodiment of a pulse wave measuring device according to the present invention. It is a figure for demonstrating the internal structure of the pulse-wave measuring apparatus shown in FIG. It is a figure which shows the state which mounted | wore the human wrist with the pulse wave measuring device which concerns on embodiment of this invention. It is a figure which shows an example of PD output according to the position of the pulse wave measuring device. It is a figure which shows the relationship between the measurement pressure in case an artery exists in the center position of a LED element and PD element, and PD output value. It is a block diagram for demonstrating the structural example of the pulse-wave measuring apparatus which concerns on this invention.

  FIG. 1 is an external perspective view of an embodiment of a pulse wave measuring device according to the present invention. The main body 1 of the pulse wave measuring device 10 of the present embodiment includes an ultrasonic transmission / reception mechanism operation switch 2, an air bag pressurization mechanism activation switch 3, a speaker 4, an air bag 5, hook-and-loop fastener bands 6a and 6b, and an exhaust valve 7. Is provided. The ultrasonic transmission / reception mechanism operation switch 2 is used to operate an ultrasonic transmission / reception element used for optimizing the position of the main body 1 with respect to the arterial position of the human wrist. The air bag pressurizing mechanism activation switch 3 is used to operate a mechanism for introducing air into the air bag 5 for mounting the main body 1 of the pulse wave measuring device 10 on a human wrist with appropriate pressure. . In addition, the speaker 4 is for outputting sound of the ultrasonic wave reflected by the human body and received by the pulse wave measuring device 10.

  The hook-and-loop fastener bands 6a and 6b are for mounting the pulse wave measuring device 10 on a human wrist. The hook-and-loop fastener band 6a is provided with an air bag 5 for attaching the main body 1 to the wrist with appropriate pressure. The exhaust valve 7 is used to exhaust the air filled in the air bag 5 to the outside of the main body 1. Thereby, the force with which the air bag 5 presses the wrist is weakened, and the pulse wave measuring device 10 can be removed from the wrist.

FIG. 2 is a diagram for explaining the internal configuration of the pulse wave measuring device shown in FIG. 1 and shows a state in which the upper outer wall of the pulse wave measuring device is partially removed so that the inside can be seen. is there.
The main body 1 of the pulse wave measuring device 10 includes an inner wall portion 1a that comes into contact with the human wrist when the pulse wave measuring device 10 is attached to the human wrist. In FIG. 2, the lower surface of the inner wall 1a comes into contact with the human wrist. In the inner wall portion 1a, PD element holes 9 and LED element holes 11 are formed at a predetermined pitch to form through holes.

  Then, a PD element and an LED element (both not shown) disposed on a circuit board (not shown) built in the main body 1 are respectively connected to the PD element hole 9 from the inside of the main body 1 toward the outside. It is inserted into the LED element hole 11 and senses the volume change of the arterial pulse wave of the human wrist.

The ultrasonic transmission / reception port 8 is an opening for transmitting an ultrasonic wave output from an ultrasonic transmission / reception element (not shown) to the outside of the main body 1 and receiving a reflected wave by the ultrasonic transmission / reception element.
When an axis connecting the PD element hole 9 and the LED element hole 11 is a Y axis (first axis), an axis passing through an intermediate position between the PD element hole 9 and the LED element hole 11 and orthogonal to the Y axis is an X axis ( The second transmission / reception port 8 is provided in the vicinity of the PD element hole 9 and the LED element hole 11 on the X axis. That is, the ultrasonic transmission / reception port 8 is disposed at a position equidistant from the LED element and the PD element. The Y axis may be defined as an axis connecting the center of the PD element hole 9 and the center of the LED element hole 11. By taking such a positional relationship, it is possible to easily perform the optimum measurement pressurization at the optimum relative position between the human artery and the photoelectric element (LED element, PD element), and more optimal volume pulse wave output. Obtainable. Details of this operation will be described later.

  FIG. 3 is a diagram showing a state in which the pulse wave measuring device according to the embodiment of the present invention is worn on a human wrist. When the pulse wave measuring device 10 of the present embodiment is worn on a human wrist, the main body 1 of the pulse wave measuring device 10 is applied to the human wrist 20, and then the surface fastener bands 6a and 6b are overlapped with each other to measure the pulse wave. The main body 1 of the apparatus 10 is temporarily attached so that it can be moved in the circumferential direction and the length direction of the wrist 20. Thereafter, the ultrasonic transmitter / receiver is activated, the main body 1 is positioned at an optimum measurement position by a method described later, and air is fed into the air bag to start measuring pulse waves.

FIG. 4 is a diagram showing an example of the output of the PD element (PD output) in accordance with the position of the pulse wave measuring device. When the pulse wave measuring device 10 is attached to the human wrist 20, the position of the artery on the human wrist The PD output value corresponding to the relationship between the PD element and the LED element of the pulse wave measuring device 10 is shown. In this example, the PD output corresponding to the artery position was measured when the arrangement pitch between the PD element and the LED element was 7 mm and when it was 9 mm.
As shown in FIG. 4, the value of the PD output detected by the pulse wave measuring device 10 is the center position between the LED element and the PD element regardless of the arrangement pitch of the PD element and the LED element of 7 mm and 9 mm. The highest value is shown when the artery is located.

  FIG. 5 is a diagram illustrating the relationship between the measured pressure and the PD output value when an artery is present at the central position between the LED element and the PD element. The measured pressure can be shown as the pressure in the air bag of the pulse wave measuring device 10. Here, the value of the PD output was measured when the LED current was 4 mA, 6 mA, and 8 mA. In any case, the higher the measurement pressure, the larger the PD output value of the pulse wave measuring device 10. If the value of the PD output is sufficiently large, an optimal pulse wave can be obtained. However, if a high measurement pressure is manually obtained, there is a high possibility that the pulse wave measuring device 10 will be misplaced, while a misalignment during wearing will occur. If it is loosely mounted to prevent this, an appropriate PD output value cannot be obtained.

  When performing pulse wave measurement using the pulse wave measuring device 10, the user of the pulse wave measuring device 10 first temporarily wears the main body 1 of the pulse wave measuring device 10 on a wrist 20 of a human (for example, himself). As described above with reference to FIG. 3, the temporary attachment is performed by placing the main body 1 of the pulse wave measuring device 10 on the human wrist 20 and then superimposing the hook-and-loop fastener bands 6 a and 6 b on each other. Is temporarily attached so that it can be moved in the circumferential direction and the length direction of the wrist 20.

Then, the user operates the ultrasonic transmission / reception mechanism operation switch 2 of the pulse wave measuring device 10 to operate the ultrasonic transmission / reception mechanism built in the main body 1. An ultrasonic wave is emitted from the ultrasonic wave transmitter / receiver by the operation of the ultrasonic wave transmission / reception mechanism to irradiate the wrist, and the reflected wave is received by the ultrasonic wave receiver. In the pulse wave measuring device 10, the reflected wave of the ultrasonic wave from the blood flow in the blood vessel is converted into an electrical signal, converted into an audio signal, and output from the speaker 4. As a result, the user can search for the blood vessel position while monitoring the audio output from the speaker 4 as an audible monitor.
In this case, the user stops the movement of the main body 1 at a position where the sound output can be heard most loudly. As a result, the human artery can be positioned substantially at the center between the LED element and the PD element disposed in the main body 1.

  The user locates the pulse wave measuring device 10 at the optimum position of the wrist 20 by monitoring the sound output from the speaker 4, and then operates the air bag pressurizing mechanism activation switch 3 so as to be built in the main body 1. The drive circuit of the air pump can be activated. By starting the drive circuit of the air pump, the air from the air pump is supplied to the air bag 5 provided in the hook-and-loop fastener band 6b of the main body 1, and the air bag 5 is inflated. As a result, the PD element and LED element surfaces respectively inserted into the PD element hole 9 and the LED element hole 11 of the inner wall 1a of the main body 1 are in close contact with the wrist 20 with an appropriate measurement pressure. At this time, since the artery of the human wrist 20 is located at the center between the LED element and the PD element, an optimal PD output value can be obtained as a volume pulse waveform.

  FIG. 6 is a block diagram for explaining a configuration example of the pulse wave measuring apparatus according to the present invention. In the pulse wave measuring device 10, when the ultrasonic transmission / reception mechanism operation switch (SW) 2 is operated, the ultrasonic transmission / reception mechanism 113 is activated, and an ultrasonic wave (for example, 8 MHz) is output from the ultrasonic transmitter / receiver 114. Are transmitted toward the outside of the main body 1 from the transmission / reception port 8 (FIG. 3). That is, by operating the ultrasonic transmission / reception mechanism operation switch 2 in a state where the main body 1 is temporarily attached to the wrist 20, ultrasonic waves are continuously applied to the living body of the wrist 20 from the transmission / reception port 8 of the main body 1.

  Then, the user moves the main body 1 so as to trace the surface of the wrist 20. At this time, the ultrasonic wave applied to the living body of the wrist 20 is reflected by the artery, and at that time, Doppler modulation is performed by the arterial flow and enters the ultrasonic transmitter / receiver 114. The ultrasonic transceiver 114 outputs a signal corresponding to the incident ultrasonic wave and is sent from the ultrasonic transmission / reception mechanism 113 to the second output device controller 115. A signal is output from the second output device 116 under the control of the second output device control unit 115. In the present embodiment, the speaker 4 shown in FIG. 1 is used as the second output device 116. Therefore, sound output according to the ultrasonic wave reflected in the living body is performed. The user can stop the ultrasonic wave by operating the ultrasonic wave transmission / reception mechanism operation switch 2 again. Alternatively, a timer or the like may be used to automatically stop the ultrasonic wave after a predetermined time has elapsed.

  The user monitors the sound output of the blood flow sound output from the speaker 4 with the body 1 of the pulse wave measuring device 10 temporarily attached to the wrist 20 while monitoring the sound output between the LED element 102 and the PD element 103. The main body 1 is set so that the artery is located substantially at the center. That is, the main body 1 is set at a position where the sound output of the blood flow sound is the largest. Here, when the user operates the air bag pressurization mechanism activation switch 3, in the pulse wave measurement device 10, the air pressure control unit 106 activates the air pump 108. Then, the air bag 5 (FIG. 1) is filled with air via the air pipe inside the main body 1.

  When the air bag 5 is filled with air, the surface of the PD element 103 and the LED element 102 inserted through the PD element hole 9 and the LED element hole 11 of the inner wall 1a of the main body 1 and the wrist 20 are appropriate. Adhering with various measuring pressures.

  A pressure sensor 107 is incorporated in the main body 1 of the pulse wave measuring device 10. The air pressure control unit 106 performs control to stop the air pump 108 when a predetermined air pressure is reached based on the measurement result by the pressure sensor 107. Thereby, an appropriate measurement pressure for the wrist 20 can be realized.

The LED driver control unit 109 controls lighting of the LED element 102 by the LED driver 101. For example, lighting control can be performed by a lighting duty, LED current, or the like. The LED element 102 may be turned on when the measurement result of the pressure sensor 107 reaches a predetermined value.
The PD element 103 receives the irradiation light from the LED element 102 reflected by the wrist artery and outputs a voltage. For example, infrared light is used as the irradiation light from the LED element 102. The volume of the artery changes in accordance with the heartbeat, and the voltage waveform output from the PD element 103 corresponds to this heartbeat. Then, the voltage waveform output from the PD element 103 is amplified by the amplifier 104, subjected to predetermined filter processing by the filter 105, and then subjected to primary differentiation or secondary differentiation by the pulse wave calculation unit 110, for example, age or blood vessel. Data characterized by the hardness of each can be obtained.

The first output device control unit 111 outputs each data calculated by the pulse wave calculation unit 110 to the first output device 112. As the first output device, for example, a device that stores data in a card-type storage medium (not shown) built in the main body 1 or a display (not shown) that displays data can be used. .
When removing the pulse wave measuring device 10 from the wrist 20, the user operates the exhaust valve 7 shown in FIG. 1 to exhaust the air filled in the air bag 5 to the outside of the main body 1. Thereby, the force which an air bag presses a wrist becomes weak, and it can remove pulse wave measuring device 10 from a wrist.

  By utilizing the present invention, it is possible to provide home and medical pulse wave observation and measurement devices capable of measuring blood vessel age, arteriosclerosis, oxygen saturation, and blood pressure as well as heart rate.

DESCRIPTION OF SYMBOLS 1 ... Main body, 1a ... Inner wall part, 2 ... Ultrasonic transmission / reception mechanism operation switch, 3 ... Air bag pressurization mechanism starting switch, 4 ... Speaker, 5 ... Air bag, 6a, 6b ... Surface fastener belt, 7 ... Exhaust valve 8 ... Transmitter / receiver port, 9 ... PD element hole, 10 ... Pulse wave measuring device, 11 ... LED element hole, 20 ... Wrist, 101 ... LED driver, 102 ... LED element, 103 ... PD element, 104 ... Amplifier, 105 ... Filter, 106 ... Air pressure control unit, 107 ... Pressure sensor, 108 ... Air pump, 109 ... LED driver control unit, 110 ... Pulse wave calculation unit, 111 ... First output device control unit, 112 ... First output device, 113 ... Super Sound wave transmission / reception mechanism, 114 ... ultrasonic wave transmitter / receiver, 115 ... second output device controller, 116 ... second output device.

Claims (2)

In a pulse wave measuring device that has a light emitting element and a light receiving element arranged at a predetermined interval and measures a pulse wave based on an electric signal obtained by converting light emitted from the light emitting element and received by the light receiving element,
An ultrasonic transceiver that transmits and receives ultrasonic waves, converts the received ultrasonic waves into electrical signals and outputs the electrical signals, and an output unit that outputs electrical signals output from the ultrasonic transceivers;
A transmission / reception port for transmitting / receiving ultrasonic waves by the ultrasonic transmitter / receiver is disposed on a second axis that passes through an intermediate position of the first axis connecting the light emitting element and the light receiving element and is orthogonal to the first axis. A pulse wave measuring device characterized by the above.   2. The pulse wave measuring apparatus according to claim 1, wherein the output means is an audio output means for outputting an electric signal output from the ultrasonic transceiver.

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