JP5683759B1 - Blood pressure measuring device and method - Google Patents

Abstract

Based on the voltage value of the vascular pulse wave signal measured by the first pressure sensor, the maximum voltage value, the minimum voltage value, and one beat time in the pressure change of the pulse wave are measured, and the second pressure is measured by the pressure application mechanism. When pressure is applied to the blood vessel via the sensor and the skin and pressurization is stopped and the blood vessel pulse wave signal is not measured, pressurization is stopped, and the pressure value of the stress is applied to the blood vessel at a predetermined first decompression speed. Depressurize with. When the vascular pulse wave signal is measured, the pressure value of the second pressure sensor immediately before is measured as the maximum blood pressure value, and the pressure value of the stress is reduced with respect to the blood vessel at a predetermined second pressure reduction rate. When the pressure value is reduced at a predetermined third pressure reduction rate and a vascular pulse wave signal having a steady pulse wave voltage value is measured, the pressure value of the second pressure sensor at that time is measured as the minimum blood pressure value.

Description

  The present invention relates to a blood pressure measurement apparatus and method using a vascular pulse wave measurement system, and in particular, to a vascular pulse wave measurement system that acquires a pulsation waveform of a blood vessel (hereinafter referred to as a pulse wave) and performs vascular pulse wave measurement. The present invention relates to a blood pressure measuring apparatus and method.

  As a technique for evaluating the characteristics of a substance, a method using vibration is known. Patent Document 1 discloses a method for converting a phase change into a frequency change in consideration of the fact that the difference in material characteristics is that the phase change is larger than the change in vibration frequency, but the accuracy of the phase measurement technique is not necessarily high. ing. An apparatus using this method includes a vibrator that injects ultrasonic waves into a substance as a vibration, a vibration detection sensor that detects a reflected wave from the substance, an amplifier having an input terminal connected to a signal output terminal of the vibration detection sensor, When there is a phase difference between the input waveform to the transducer and the output waveform from the vibration detection sensor, it is provided between the output end of the amplifier and the input end of the transducer. Including a phase shift circuit for shifting the phase difference to zero and a frequency change amount detecting means for detecting a frequency change amount for shifting the phase difference to zero.

  In the apparatus of Patent Document 1, specifically, in a hardness measuring device using a frequency deviation detection circuit, hardness information is accurately measured in a wide range from a soft measurement object to a hard measurement object. Therefore, a contact element, a vibrator, a self-excited oscillation circuit, and a gain change correction circuit are provided, the self-excited oscillation circuit feeds back vibration information of the vibrator to a resonance state, and the gain change correction circuit is provided in the self-excited oscillation circuit. The gain change correction circuit has a center frequency different from the center frequency of the self-excited oscillation circuit, and increases the gain with respect to the change in frequency.

  In the above apparatus, the frequency change amount detecting means shifts the phase difference due to the difference in hardness to zero and converts it to a frequency change amount. In this conversion, a reference transfer function indicating a relationship between the amplitude gain and the phase of the reflection of the reflection with respect to the frequency is obtained in advance and used. Moreover, although ultrasonic vibration is used as vibration, this can be used as vibration of an electric signal in an electric circuit. For example, a light emitting element is driven by a driving signal to emit light, the light is detected by a light receiving element, and a detection signal is fed back as a driving signal for the light emitting element. Thus, a feedback loop is formed. Signal vibration can be used.

  That is, there is a signal delay due to the structure of the light emitting element between the drive signal of the light emitting element and the emitted optical signal. Similarly, the optical signal incident on the light receiving element and the detection signal output by the light receiving element There is also a signal delay due to the structure of the light receiving element. Therefore, when a feedback loop is formed by combining a light emitting element and a light receiving element, self-excited oscillation occurs so that the phase difference that is a delay between them is made zero. By providing the feedback loop with the phase shift circuit disclosed in Patent Document 1, the phase difference can be converted into a frequency difference.

  When the light emitted from the light emitting element is applied to the substance to be evaluated, the light reflected from the substance is received by the light receiving element, and the above feedback loop is formed, the frequency of the self-excited oscillation circuit is determined by the light receiving element and the light emitting element. It depends on the delay caused by the structure of the substance and the delay caused by the characteristics of the substance to be evaluated. Therefore, by providing a phase shift circuit in the feedback loop, converting the phase difference for each frequency and observing the frequency difference, the material characteristics can be measured in a non-contact or non-invasive manner.

  For example, in Patent Document 2, as a blood pressure measurement device, a sensor unit that transmits infrared light into the body and receives a reflected wave in the body, and an electric signal based on the received reflected wave is fed back to the transmitting unit. Self-oscillation circuit that self-oscillates, and the self-oscillation circuit changes the gain with respect to the change in frequency and adjusts the phase difference between the input phase and the output phase to zero to promote feedback oscillation It is described that the blood pressure is calculated based on the oscillation frequency of the self-excited oscillation circuit obtained in this way.

  In the apparatus of Patent Document 2, in order to accurately measure blood pressure and reduce the burden on the person being measured, the wave transmitting unit converts an electric signal to transmit electromagnetic waves or ultrasonic waves such as infrared light into the body. The receiving unit receives the reflected wave in the body and converts it into an electrical signal. The frequency of the self-excited oscillation circuit measured by the frequency measuring unit is determined based on the correlation parameter called by the blood pressure calculating unit. The blood pressure value or blood pressure waveform is sequentially displayed on the display unit.

  As described above, according to the technique of the phase shift method, the pulsation waveform of the blood vessel can be accurately obtained using the light emitting element and the light receiving element. However, a living body that measures the pulsation of a blood vessel, for example, a measurement subject, does not always maintain a stable state during measurement. The posture may change, such as moving the arm to which the light emitting element and the light receiving element are attached, and if the mounting state of the light emitting element and the light receiving element is incomplete, the mounting state changes during measurement. Sometimes.

  Therefore, the pulsation waveform gradually changes during measurement, and for example, it may occur that the measurement range and the calculation range are deviated. If the pulsation waveform deviates from the measurement range in this way, accurate blood vessel pulse wave measurement cannot be performed. In order to solve the problem, in order to provide a vascular pulse wave measurement system that enables more accurate measurement, the applicant of the present application proposed the following vascular pulse wave measurement system in Patent Document 3.

  The blood vessel pulse wave measurement system disclosed in Patent Literature 3 is connected to an optical probe attached to a site suitable for acquiring pulsation of a blood vessel of a measurement subject, and connected to the optical probe via an optical probe circuit, and a phase shift method. A pulsation waveform output unit that outputs a pulsation waveform as a change in frequency over time, and an arithmetic processing unit. The floating median value setting processing module of the arithmetic processing unit has a maximum amplitude value of periodic frequency data within the arithmetic range The maximum amplitude value is amplified so as to have a predetermined ratio to the above, and the median value is floatingly set to the median value of the calculation range regardless of the absolute value.

  Furthermore, in Patent Document 4, a respiratory abnormality detection apparatus including a respiratory abnormality determination unit that obtains a pulse rate and a pulse amplitude based on a pulse wave signal indicating a state of a pulse wave and determines a respiratory abnormality based on the pulse number and pulse amplitude is provided. Proposed. In this device, for example, respiratory abnormalities are detected based on the ratio between the pulse wave amplitude and the pulse rate per unit time, or based on a change in respiratory rate, a change in pulse rate, or a change in oxygen saturation concentration in blood. It is characterized by detecting respiratory abnormalities.

However, in each device according to the prior art disclosed in Patent Documents 1 to 3,
(A) In addition to changes in the mounting state of the light emitting element and the light receiving element,
(B) For example, depending on whether it is attached to the radial artery of the wrist or attached to the fingertip,
(C) Moreover, even if it attaches to the site | part of the same radial artery part, for example, according to the thickness of the person's skin with a thin measured person and a fat measured person,
(D) Further, for example, a type of optical probe that uses a reflection type optical probe that uses light reflected from a blood vessel or a transmission type optical probe that uses light passing through a blood vessel is used. Depending on,
The blood vessel pulsation acquisition operation is often in an unstable state, and pulsation waveform data cannot be acquired frequently, and there is a problem that it is hardly usable at the measurement site.

  Further, the respiratory abnormality detection device according to the prior art disclosed in Patent Document 4 has a problem that the detection accuracy of respiratory abnormality is still low in addition to the above problems.

On the other hand, even when the propagation distance of light from the light emitting element to the light receiving element is different, pulsation waveform data can be acquired with a simpler structure compared to the prior art, and blood vessel pulse wave measurement can be performed. A blood vessel pulse wave measurement system is disclosed in Patent Document 7. Here, the vascular pulse wave measurement system disclosed in Patent Document 7 is:
An optical probe including a light emitting element that emits light to a blood vessel through the skin, and a light receiving element that receives reflected light from the blood vessel or transmitted light through the blood vessel through the skin;
A driving circuit for driving the light emitting element based on an input driving signal;
In a blood vessel pulse wave measurement system that performs blood vessel pulse wave measurement using an optical probe circuit including a detection circuit that converts light received by the light receiving element into an electrical signal and outputs the electrical signal,
Measurement means for generating a self-excited oscillation signal from the detection circuit and measuring the self-excited oscillation signal as a vascular pulse wave signal by directly synchronously feeding back the electrical signal as the drive signal to the drive circuit;
Control means for controlling an operating point of at least one of the detection circuit and the drive circuit so that the level of the self-excited oscillation signal is substantially maximized.

JP-A-9-145691 Japanese Patent Laid-Open No. 2001-187032 International Publication 2010/088993 Pamphlet JP 2004-121668 A Japanese Patent Laid-Open No. 6-169892 JP 2005-021477 A International Publication 2012/1010151 Pamphlet

Edited by Japan Society for Medical and Biological Engineering, “Rheology and Blood Flow of Blood”, Corona, April 25, 2003, 120-121

  However, the blood vessel pulse wave measurement system disclosed in Patent Document 7 has a problem that the optical probe circuit including the optical probe, the drive circuit, and the detection circuit is relatively large. Further, when a blood pressure measurement device is configured using the optical probe circuit, it is necessary to further include a pressure sensor and a pressure application mechanism, so that the device configuration becomes complicated and the device size increases. there were.

  An object of the present invention is to solve the above-mentioned problems, a blood pressure measuring device that can measure a blood pressure value with high accuracy, and can be configured to have a simpler device configuration and a significantly smaller device size as compared with the prior art. It is to provide a method.

The blood pressure measurement device according to the first invention is:
A first pressure sensor that is provided through the skin on the blood vessel and detects a pressure change of the pulse wave flowing through the blood vessel and measures it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measuring device comprising control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The control means applies pressure to the blood vessel by applying pressure to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism and stops measuring the blood vessel pulse wave signal. When the vascular pulse wave signal is measured after stopping, the pressure value of the second pressure sensor immediately before that is measured as the maximum blood pressure value, and then the pressure value is further reduced and the voltage value of a predetermined steady pulse wave When the vascular pulse wave signal having the above is measured, the pressure value of the second pressure sensor at that time is measured as the minimum blood pressure value.

In the blood pressure measurement device, the control means includes
(1) When the blood vessel pulse wave signal is measured, based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor, the maximum voltage value and the minimum voltage value in the pressure change of the pulse wave are A pre-measurement process of a stationary pulse wave for measuring one beat time;
(2) Next, when the pressure application mechanism no longer measures the blood vessel pulse wave signal by applying stress to the blood vessel via the second pressure sensor and the skin through the pressure application mechanism, pressurization is performed. Pressure treatment to stop,
(3) Next, a first depressurization process for depressurizing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined first depressurization rate;
(4) a first measurement process for measuring, as the maximum blood pressure value, the pressure value of the second pressure sensor immediately before the vascular pulse wave signal is measured in the first decompression process;
(5) Next, a second decompression process for decompressing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined second decompression rate;
(6) Next, a third pressure reduction process for reducing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined third pressure reduction rate;
(7) When a blood vessel pulse wave signal having a steady pulse wave voltage value in the prior measurement process is measured in the third decompression process, the pressure value of the second pressure sensor at that time is measured as the minimum blood pressure value. Performing a second measurement process,
At least the first and third decompression speeds are set to be inversely proportional to the measured one beat time.

  Further, in the blood pressure measurement device, the control means may be configured to reduce the pressure value by stepwise reducing the pressure value stepwise in at least one of the first pressure reduction process and the third pressure reduction process. The pressure application mechanism is controlled so as to perform the following.

  Further, in the blood pressure measurement device, the control means executes the pressure reduction in the step pressure reduction method in synchronization with the vascular pulse wave signal.

Furthermore, the blood pressure measurement device further includes a clock recovery circuit that recovers a clock from the vascular pulse wave signal,
The control means executes the pressure reduction in the step pressure reduction method in synchronization with the vascular pulse wave signal based on the regenerated clock.

  Furthermore, in the blood pressure measurement device, the second decompression speed is set to be faster than the first and third decompression speeds.

  Further, in the blood pressure measurement device, the control means controls the pressure application mechanism so that the second pressure reduction process is performed so that the pressure value is linearly reduced with respect to time by a linear pressure reduction method. .

  Furthermore, in the blood pressure measurement device, the first and second pressure sensors are MEMS pressure sensors that detect a pressure change of a pulse wave flowing in the blood vessel as a resistance value change.

Furthermore, in the blood pressure measurement device, the first pressure sensor is
An optical probe including a light emitting element that emits light to a blood vessel through the skin, and a light receiving element that receives reflected light from the blood vessel or transmitted light through the blood vessel through the skin;
A driving circuit for driving the light emitting element based on an input driving signal;
An optical sensor comprising an optical probe circuit including a detection circuit that converts the light received by the light receiving element into an electrical signal and outputs the electrical signal;
The second pressure sensor is a MEMS pressure sensor that detects a pressure change of a pulse wave flowing in the blood vessel as a resistance value change.

A blood pressure measurement device according to a second invention
A first pressure sensor having a pressure value calibrated in advance and provided through the skin on the blood vessel to detect a pressure change of the pulse wave flowing in the blood vessel and measuring it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measuring device comprising control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The control means includes
(1) When the blood vessel pulse wave signal is measured, based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor, the maximum voltage value and the minimum voltage value in the pressure change of the pulse wave are And measuring the maximum pressure value and the minimum pressure value respectively corresponding to the maximum voltage value and the minimum voltage value based on the maximum voltage value, the minimum voltage value, and a predetermined calibration value. Processing,
(2) Next, when the pressure application mechanism no longer measures the blood vessel pulse wave signal by applying stress to the blood vessel via the second pressure sensor and the skin through the pressure application mechanism, pressurization is performed. Pressure treatment to stop,
(3) Next, a first depressurization process for depressurizing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined first depressurization rate;
(4) a first measurement process for measuring, as the maximum blood pressure value, the pressure value of the second pressure sensor immediately before the vascular pulse wave signal is measured in the first decompression process;
(5) A third measurement process for estimating and measuring a minimum blood pressure value based on the measured maximum blood pressure value, the maximum pressure value, and the minimum pressure value is performed. .

In the blood pressure measurement device, the control means further measures one beat time in the pressure change of the pulse wave based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor,
The first decompression speed is set to be inversely proportional to the measured one beat time.

  In the blood pressure measurement device, the control means controls the pressure application mechanism so that the pressure value is lowered stepwise by the step pressure reduction method in the first pressure reduction process to perform the pressure reduction. Features.

  Further, in the blood pressure measurement device, the control means executes the pressure reduction in the step pressure reduction method in synchronization with the vascular pulse wave signal.

Furthermore, the blood pressure measurement device further includes a clock recovery circuit that recovers a clock from the vascular pulse wave signal,
The control means executes the pressure reduction in the step pressure reduction method in synchronization with the vascular pulse wave signal based on the regenerated clock.

  In the blood pressure measurement device, the first and second pressure sensors are MEMS pressure sensors that detect a pressure change of a pulse wave flowing through the blood vessel as a resistance value change.

  Furthermore, in the blood pressure measurement device, the pressure application mechanism is a pressure actuator that applies a predetermined pressure to the blood vessel via the first and second pressure sensors and the skin.

Still further, in the blood pressure measurement device, the pressure application mechanism includes a pair of adjacent five of the first to fifth uniaxial joints to which the uniaxial joints at both ends are fixed and the five uniaxial joints. A five-joint link mechanism comprising four links connecting a single-axis joint;
The first and second pressure sensors are provided at the third joint,
The measuring means moves the position of the third uniaxial joint by rotating the uniaxial joints at both ends, so that the five-joint link mechanism is moved from the third uniaxial joint to the first and second pressures. A predetermined pressure is applied to the blood vessel through the sensor and the skin.

A blood pressure measurement method according to a third invention comprises:
A first pressure sensor that is provided through the skin on the blood vessel and detects a pressure change of the pulse wave flowing through the blood vessel and measures it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measurement method for a blood pressure measurement device comprising a control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The control means includes
When pressure is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism to pressurize and the blood vessel pulse wave signal is not measured, the pressurization is stopped and then the pressure is reduced. Thereafter, when the vascular pulse wave signal is measured, the pressure value of the second pressure sensor immediately before that is measured as the maximum blood pressure value, and then the pressure is further reduced, and the vascular pulse wave having a predetermined steady-state pulse wave voltage value. When the signal is measured, the step of measuring the pressure value of the second pressure sensor at that time as the minimum blood pressure value is executed.

In the blood pressure measurement method, the measurement means includes:
(1) When the blood vessel pulse wave signal is measured, based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor, the maximum voltage value and the minimum voltage value in the pressure change of the pulse wave are A pre-measurement process of a stationary pulse wave for measuring one beat time;
(2) Next, when the pressure application mechanism no longer measures the blood vessel pulse wave signal by applying stress to the blood vessel via the second pressure sensor and the skin through the pressure application mechanism, pressurization is performed. Pressure treatment to stop,
(3) Next, a first depressurization process for depressurizing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined first depressurization rate;
(4) a first measurement process for measuring, as the maximum blood pressure value, the pressure value of the second pressure sensor immediately before the vascular pulse wave signal is measured in the first decompression process;
(5) Next, a second decompression process for decompressing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined second decompression rate;
(6) Next, a third pressure reduction process for reducing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined third pressure reduction rate;
(7) When a blood vessel pulse wave signal having a steady pulse wave voltage value in the prior measurement process is measured in the third decompression process, the pressure value of the second pressure sensor at that time is measured as the minimum blood pressure value. Performing a second measurement process,
At least the first and third decompression speeds are set to be inversely proportional to the measured one beat time.

A blood pressure measurement method according to a fourth invention comprises:
A first pressure sensor having a pressure value calibrated in advance and provided through the skin on the blood vessel to detect a pressure change of the pulse wave flowing in the blood vessel and measuring it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measurement method for a blood pressure measurement device comprising a control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The control means includes
(1) When the blood vessel pulse wave signal is measured, based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor, the maximum voltage value and the minimum voltage value in the pressure change of the pulse wave are And measuring the maximum pressure value and the minimum pressure value respectively corresponding to the maximum voltage value and the minimum voltage value based on the maximum voltage value, the minimum voltage value, and a predetermined calibration value. Processing,
(2) Next, when the pressure application mechanism no longer measures the blood vessel pulse wave signal by applying stress to the blood vessel via the second pressure sensor and the skin through the pressure application mechanism, pressurization is performed. Pressure treatment to stop,
(3) Next, a first depressurization process for depressurizing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined first depressurization rate;
(4) a first measurement process for measuring, as the maximum blood pressure value, the pressure value of the second pressure sensor immediately before the vascular pulse wave signal is measured in the first decompression process;
(5) A third measurement process for estimating and measuring a minimum blood pressure value based on the measured maximum blood pressure value, the maximum pressure value, and the minimum pressure value is performed. .

  According to the blood pressure measurement apparatus and method of the present invention, blood pressure values can be measured with extremely simple calibration and high accuracy using pulse wave waveform data as compared with the prior art.

1 is a block diagram illustrating a configuration of a vascular pulse wave measurement system according to a first embodiment of the present invention. It is a side view which shows the detailed structure of the pulse wave and pressure detection application apparatus 20 of FIG. It is a side view which shows operation | movement of the 5-joint link mechanism 21 which is a pressure application mechanism of the pulse wave and pressure detection application apparatus 20 of FIG. FIG. 4 is a plan view showing an arrangement configuration of a plurality of N unit sensor circuits 31-1 to 31 -N constituting the MEMS pressure sensor 30 of FIGS. 2 and 3. It is a circuit diagram which shows the circuit structure of the MEMS pressure sensor 30 of FIG. It is a front view which shows an example at the time of attaching the pulse wave and pressure detection application apparatus 20 of FIG.2 and FIG.3 to the radial artery part 7 of a to-be-measured person's wrist. It is a front view which shows an example at the time of attaching the pulse wave and pressure detection application apparatus 20 of FIG.2 and FIG.3 to the to-be-measured person's fingertip 9. FIG. It is a graph which shows the maximum voltage value Vmax and the minimum voltage value Vmin of the pulse wave voltage value measured by the vascular pulse wave measurement system of FIG. It is a graph which shows the maximum blood pressure value Pmax and the minimum blood pressure value Pmin of the blood pressure value corresponding to the pulse wave voltage value measured by the vascular pulse wave measurement system of FIG. It is a graph which shows conversion from the pulse wave voltage value measured by the vascular pulse wave measurement system of Drawing 1 to a blood pressure value. 2 is a graph showing a pulsation waveform measured by the vascular pulse wave measurement system of FIG. 1 converted into a blood pressure waveform. 2 is a graph showing an operation of processing a pulsation waveform using a moving average method in the vascular pulse wave measurement system of FIG. 1. (A) is a graph which shows an example of the various signal waveforms at the time of a certain person's awakening measured by the vascular pulse wave measurement system of FIG. 1, (b) is measured by the vascular pulse wave measurement system of FIG. It is a graph which shows an example of the various signal waveforms at the time of a certain patient's apnea. (A) is a figure which models and shows the change of the maximum blood pressure value Pmax at the time of awakening, (b) is a figure which models and shows the change of the maximum blood pressure value Pmax at the time of apnea. It is a flowchart which shows the blood pressure value calibration process performed by the blood pressure value calibration process module 52 of the apparatus controller 50 of FIG. 6 is a flowchart showing blood vessel pulse wave measurement executed by a blood vessel pulse wave measurement processing module 51 of the apparatus controller 50 of FIG. 1. It is a flowchart which shows the sleep state discrimination | determination process performed by the sleep state discrimination | determination processing module 53 of the apparatus controller 50 of FIG. It is a longitudinal cross-sectional view which shows the structure of the pulse wave and pressure detection application apparatus 20A provided with the pressure actuator 36 and the MEMS pressure sensor 30 based on the 1st modification of this invention. It is a longitudinal cross-sectional view which shows the structure of the pulse wave and pressure detection application apparatus 20B provided with the MEMS pressure sensor 30 pressed with human fingertips, such as a test subject, in the 2nd modification of this invention. It is a side view which shows the structure of the modification of the pulse wave and pressure detection application apparatus 20 of FIG.2 and FIG.3 based on the 3rd modification of this invention. It is a longitudinal cross-sectional view which shows the structure of the pulse wave and pressure detection application apparatus 20C provided with the pressure actuator 36 and the MEMS pressure sensor 30 based on the 4th modification of this invention. It is a longitudinal cross-sectional view which shows the structure of the pulse wave and pressure detection application apparatus 20D provided with the MEMS pressure sensor 30 pressed with human fingertips, such as a test subject, in the 5th modification of this invention. It is a perspective view when the pulse wave and pressure detection application device 20E used for the blood pressure measurement device according to the second embodiment of the present invention is attached to the radial artery portion 7 of the wrist. FIG. 20 is a timing chart of blood pressure measurement processing executed by the blood pressure measurement device of FIG. 19. FIG. It is a flowchart of the blood-pressure measurement process performed by the apparatus controller 50 (FIG. 1) of the blood-pressure measurement apparatus of FIG. FIG. 20 is a block diagram showing a configuration of a circuit for generating a decompression step instruction signal from a vascular pulse wave signal in the blood pressure measurement device of FIG. 19. It is a timing chart of the blood-pressure measurement process performed by the blood-pressure measurement apparatus which concerns on the modification of 2nd Embodiment. It is a flowchart of the blood-pressure measurement process performed by the apparatus controller 50 (FIG. 1) of the blood-pressure measuring apparatus which concerns on the modification of 2nd Embodiment. It is a perspective view when the pulse wave and pressure detection application device 20F used for the blood pressure measurement device according to the third embodiment of the present invention is attached to the radial artery portion 7 of the wrist. It is a side view which shows the structure of the reflection type optical probe 112 in the optical probe circuit 120 of FIG. FIG. 26 is a circuit diagram showing a configuration of the optical probe circuit 120 in FIG. 25.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each following embodiment, the same code | symbol is attached | subjected about the same component. In the following, the pulse wave of a human blood vessel will be described as a measurement target. However, any pulse wave of a blood vessel of a living body may be used, and an animal other than a human can be targeted. In the following description, measurement of pulse, maximum blood pressure, and minimum blood pressure will be described as blood vessel pulse wave measurement. However, any other measurement may be used as long as measurement is performed using a blood vessel pulsation waveform. For example, the measurement corresponding to the blood flow volume may be performed from the integral value of the pulse waveform, and the measurement for evaluating the flexibility of the blood vessel may be performed from the differential value of the pulsation waveform. The materials, shapes, etc. described below are examples, and these contents may be appropriately changed according to the purpose of use.

First embodiment.
FIG. 1 is a block diagram showing a configuration of a vascular pulse wave measurement system according to the first embodiment of the present invention. FIG. 2 is a side view showing a detailed configuration of the pulse wave and pressure detection application device 20 of FIG.

  In FIG. 1, although not a constituent element of the vascular pulse wave measurement system 10, a subject 6 to be measured for measuring blood pressure and the like is shown. In the following drawings, the illustration of the skin of the person to be measured 6 is omitted. The vascular pulse wave measurement system 10 according to the present embodiment is a compression cuff method for measuring Korotkoff sounds that is conventionally used, or a catheter connected with a pressure sensor is inserted into an artery to invade the pressure inside the blood vessel. As shown in FIGS. 1 and 2, instead of the direct blood measurement method, a MEMS (Micro Electro Mechanical Systems) pressure sensor 30 and a Wheatstone bridge circuit 15 in the pulse wave and pressure detection application device 20 (FIG. 5) Is a system for acquiring a pulsation waveform of a blood vessel and measuring a pulse wave, and in particular, a MEMS pressure sensor 30 for measuring pressure, a Wheatstone bridge circuit 15 (FIG. 5), and a 5-joint link mechanism which is a pressure application mechanism. 21 is characterized in that blood pressure is measured using a pulse wave and pressure detection application device 20 provided with 21.

As shown in FIG. 1 and FIG.
(A) a pulse wave and pressure detection and application device 20 provided with a MEMS pressure sensor 30 and a five-joint link mechanism 21 which is a pressure application mechanism attached to a site suitable for acquiring pulsation of a blood vessel of the person to be measured 6;
(B) a voltage amplifier 32 that amplifies the output voltage Vout from the MEMS pressure sensor 30 of the pulse wave and pressure detection application device 20;
(C) an A / D converter 33 for A / D converting the output voltage from the voltage amplifier 32 into digital data and outputting the digital data to the device controller 50;
(D) a control signal line 34 for outputting control signals Sc1 and Sc2 (preferably a stepping pulse signal) from the device controller 50 to the stepping motors M1 and M2 of the five-joint link mechanism 21;
(E) A control device such as a digital computer including an internal memory 50m, which includes a blood vessel pulse wave measurement processing module 51, a blood pressure value calibration processing module 52, and a sleep state determination processing module 53, and performs A / D conversion. The digital data from the device 33 is processed to generate vascular pulse wave data, and blood pressure value calibration processing (FIG. 13), vascular pulse wave measurement processing (FIG. 14) and sleep state determination processing (FIG. 13) are performed on the vascular pulse wave data. 15) a device controller 50 for executing
(F) A display or printer, for example, based on output data from the device controller 50, pulsation waveform display (pulsation waveform display 61 after moving average processing and pulsation waveform display 62 after low-pass filter processing) and each vascular pulse A display unit 60 for displaying a wave measurement value display (pulse, maximum blood pressure value Pmax and minimum blood pressure value Pmin);
It is configured with.

  As shown in FIG. 1, an output voltage signal (AC) from the MEMS pressure sensor 30 of the pulse wave and pressure detection application device 20 is output to the device controller 50 via an amplifier 32 and an A / D converter 33. Here, when the blood vessel changes due to pulsation, the AC output voltage Vout from the MEMS pressure sensor 30 changes, that is, the output voltage Vout changes corresponding to the change in pulsation. In addition, regarding the pressure measurement to the blood vessel in the blood pressure value calibration processing of FIG. 13, the pressure applied to the blood vessel is measured by measuring the time average value (time integral value) of the output voltage Vout from the MEMS pressure sensor 30. .

  In the prior arts such as Patent Documents 1 to 3, since a large change in output voltage could not be obtained, the change in frequency was converted into a change in voltage to detect a change in pulsation. As shown in FIGS. 1 and 2, by measuring the output voltage Vout from the MEMS pressure sensor 30, a pulsation waveform can be obtained very easily. Further, the pressure applied to the blood vessel can be measured using the same MEMS pressure sensor 30 as described above. Therefore, as shown in FIG. 2, the pulse wave and pressure detection application device 20 includes, for example, an integrated MEMS pressure sensor 30 and a 5-joint link mechanism 21 including two stepping motors M1 and M2. Compared to the above, it can be configured with a simpler configuration and with a smaller size. When blood pressure is not measured only by pulse wave measurement, the five-joint link mechanism 21 is unnecessary and becomes extremely smaller.

  Next, the configuration and operation of the five-joint link mechanism 21 of the pulse wave and pressure detection application device 20 will be described below with reference to FIGS. FIG. 2 is a side view showing a detailed configuration of the pulse wave and pressure detection application device 20 of FIG. 1, and FIG. 3 is a diagram of a five-joint link mechanism 21 that is a pressure application mechanism of the pulse wave and pressure detection application device 20 of FIG. It is a side view which shows operation | movement.

  In FIG. 2, the pulse wave and pressure detection application device 20 includes a five-joint link mechanism 21 having two stepping motors M1 and M2 and a MEMS pressure sensor 30 attached to the tip of the joint J3. Is done. The five-joint link mechanism 21 includes five uniaxial joints J1 to J5 and linear bar-shaped links L1 to L4 that connect a pair of adjacent joints of the joints J1 to J5. Here, the joint J1 whose position is fixed is connected to the joint J2 via the link L1, and the joint J2 is connected to the joint J3 via the link L2. The joint J3 is connected to the joint J4 via the link L3, and the joint J4 is connected to the joint J5 whose position is fixed via the link L4. The links L1 to L4 more preferably have the same length as each other, or preferably the links L1 and L4 have the same length as each other and the links L2 and L3 have the same length as each other.

  The housing 22 has bearing holes 22a and 22b which are separated by a predetermined distance and are parallel to each other, and the axis of the joint J1 is inserted into the bearing hole 22a so as to be rotatable around an axis parallel to Z perpendicular to the XY plane. The shaft of the joint J5 is inserted into the bearing hole 22b so as to be rotatable around an axis parallel to Z perpendicular to the XY plane. The axis of the joint J1 is connected to the rotation axis of the stepping motor M1, and the axis of the joint J5 is connected to the rotation axis of the stepping motor M2. Here, control signals Sc1 and Sc2 received from the device controller 50 via the control signal line 34 are applied to the stepping motors M1 and M2. The five-joint link mechanism 21 including the stepping motors M1 and M2, the casing 22, and the MEMS pressure sensor 30 are covered with a device cover case (not shown) such as a flexible resin.

  When the axes of the joints J1 and J5 whose positions are fixed are rotated by the stepping motors M1 and M2 in the normal rotation (clockwise rotation in FIG. 3) or the reverse rotation (counterclockwise rotation in FIG. 3), respectively. The respective axes of the joints J1 to J5 are parallel to each other, the links L1 to L4 move substantially on one plane, and the joints J2 to J4 move on the plane, but the joint J3 is in the X direction or It can be moved in the −X direction, the Y direction, the −Y direction, or a combination thereof. In the present embodiment, as shown in FIG. 2, the joint J3 is moved via the MEMS pressure sensor 30 directly above the radial artery 7 of the wrist of the person to be measured or the blood vessel 8 of the fingertip 9 and the stress 21f is applied. The five-joint link mechanism 21 is controlled using the following control signals Sc1 and Sc2. Note that the relationship between the rotational positions of the stepping motors M1 and M2 and the position of the joint J3 is measured in advance and managed and stored by the device controller 50, and when the predetermined control signals Sc1 and Sc2 are output from the initial setting position. The rotational position is also managed and stored.

(1) Initial setting control signals Sc1 and Sc2 for setting the positions of the joint J3 and the MEMS pressure sensor 30 to predetermined initial setting positions (for example, the positions in FIG. 2).
(2) The positions of the joint J3 and the MEMS pressure sensor 30 are moved in the −Y direction by a predetermined distance, and applied to the radial artery portion 7 or the fingertip 9 of the measurement subject's wrist with a predetermined pressure width. Pressure increase control signals Sc1 and Sc2. The pressurization speed can be changed by the pressure increase control signals Sc1 and Sc2, and the pressure value can be changed, for example, linearly or stepwise (stepwise) with respect to time.
(3) The position of the joint J3 and the MEMS pressure sensor 30 is moved in the Y direction by a predetermined distance, and applied to the radial artery portion 7 or the fingertip 9 of the subject's wrist by decreasing and reducing the pressure by a predetermined pressure range. The control signal Sc1, Sc2 for lowering the pressure. The pressure reduction degree can be changed by the pressure lowering control signals Sc1 and Sc2, and the pressure value can be changed, for example, linearly or stepwise (stepwise) with respect to time.

  In addition, as a method of fixing the MEMS pressure sensor 30 to the radial artery portion 7 or the fingertip 9 of the wrist of the person to be measured, the MEMS pressure sensor 30 may be fixed using a cuff, an adhesive sheet, or an adhesive tape. It may be fixed.

  Next, the configuration and operation of the MEMS pressure sensor 30 of the pulse wave and pressure detection application device 20 will be described below with reference to FIGS. 4 and 5. 4 is a plan view showing an arrangement of a plurality of N unit sensors 31-1 to 31-N constituting the MEMS pressure sensor 30 of FIGS. 2 and 3, and FIG. 5 is a plan view of the MEMS pressure sensor 30 of FIG. It is a circuit diagram which shows a circuit structure.

  In FIG. 4, a MEMS pressure sensor 30 is a device in which mechanical element parts, pressure sensors, actuators, and electronic circuits are integrated on a substrate such as a silicon substrate, a glass substrate, or an organic material substrate as shown below. As shown in FIG. 4, a plurality of N unit sensor circuits 31-1 to 31 -N are arranged in a plurality of two-dimensional arrangement shapes such as 8 × 8, for example, and more preferably integrated. Is done. In FIG. 5, the unit sensor circuit 31-1 includes a DC voltage source 11 having a DC voltage Vin, and a Wheatstone bridge circuit 15 including resistors R1 to R3 and a MEMS sensor resistor 12 having a resistance value Rx. . Here, the DC voltage Vin from the DC voltage source 11 is applied to two predetermined connection terminals facing each other of the Wheatstone bridge circuit 15, while the output voltage Vo is obtained from the other two connection terminals. Here, in the resistors R1, R2, R3, and Rx of the Wheatstone bridge circuit 15, each resistance value is preferably set so as to be in an equilibrium state according to the following equation.

R2 / R1 = Rx / R3 (1)

  The other unit sensor circuits 31-2 to 31-N are configured in the same manner as the unit sensor circuit 31-1. Here, the output voltages from the unit sensor circuits 31-1 to 31-N are Vo1 to VoN, respectively, and the output voltages Vo1 to VoN from the unit sensor circuits 31-1 to 31-N are connected in series to output voltage. Vout is obtained. In the present embodiment, the resistance value Rx of the MEMS sensor resistor 12 of the MEMS pressure sensor 30 changes depending on the applied pressure, the amount of change is detected by the Wheatstone bridge circuit 15, and the output voltage changes corresponding to the amount of pressure change. Vout is obtained.

  In the embodiment of FIG. 5, the output voltages Vo1 to VoN from the unit sensor circuits 31-1 to 31-N are connected in series to obtain the output voltage Vout. However, the present invention is not limited to this and is connected in parallel. The output voltage Vout may be obtained by connection, or a predetermined calculated value such as an average value of the output voltages Vo1 to VoN may be calculated to obtain the output voltage Vout. In the present embodiment, a plurality of N unit sensor circuits 31-1 to 31-N are used. However, the present invention is not limited to this, and a single unit sensor circuit may be used.

  FIG. 6 is a front view showing an example when the pulse wave and pressure detection application device 20 of FIGS. 2 and 3 is attached to the radial artery portion 7 of the wrist of the person to be measured. As shown in FIG. 6, the pulse wave measurement and blood pressure measurement can be performed by attaching the pulse wave and pressure detection and application device 20 of FIGS. 2 and 3 to the radial artery portion 7 of the wrist of the measurement subject.

  FIG. 7 is a front view showing an example when the pulse wave and pressure detection application device 20 of FIGS. 2 and 3 is attached to the fingertip 9 of the person to be measured. As shown in FIG. 7, the pulse wave measurement and blood pressure measurement can be performed by attaching the pulse wave and pressure detection application device 20 of FIGS. 2 and 3 to the fingertip 9 of the measurement subject.

  FIG. 8A is a graph showing the maximum voltage value Vmax and the minimum voltage value Vmin of the pulse wave voltage value (for example, the output voltage value of the voltage amplifier 30) measured by the vascular pulse wave measurement system of FIG. As is clear from FIG. 8A, the pulse wave voltage value periodically changes according to the change in pulsation, takes the maximum voltage value Vmax and the minimum voltage value Vmin, and the time between two adjacent minimum voltage values Vmin. The period is defined as a time period Tint.

  FIG. 8B is a graph showing the maximum blood pressure value Pmax and the minimum blood pressure value Pmin of the blood pressure values corresponding to the pulse wave voltage values measured by the vascular pulse wave measurement system of FIG. As is clear from FIG. 8B, the blood pressure value periodically changes in the same manner as the pulse wave voltage value of FIG. 8A according to the change in pulsation, and takes the maximum blood pressure value Pmax and the minimum blood pressure value Pmin. The conversion between FIG. 8A and FIG. 8B can be performed with a conversion formula (which may be a conversion table) generated by the blood pressure value calibration processing of FIG. 19 as described with reference to FIG. 8C. .

  FIG. 8C is a graph showing the conversion from the pulse wave voltage value measured by the blood vessel pulse wave measurement system of FIG. 1 into a blood pressure value. As is well known, since the correlation between the pulse wave voltage value and the blood pressure value is different for each person to be measured, it is necessary to obtain the correlation for each person to be measured in advance. Even if the subject is the same, the correlation between the pulse wave voltage value and the blood pressure value may be different between the resting state and the exercise state. It is necessary to ask for it. The correlation between the pulse wave voltage value and the blood pressure value obtained by the vascular pulse wave measurement system in FIG. 1 is associated with each measurement condition for each measurement condition and is converted into a conversion formula (or conversion table). It is stored in the internal memory 50m of the controller 50. FIG. 8C shows that the conversion formulas Q1 and Q2 differ from the measurement subject. When conversion from the pulse wave voltage value to the blood pressure value is performed in this manner, blood vessel pulse wave measurements such as the pulse rate, the maximum blood pressure Pmax, and the minimum blood pressure Pmin can be performed based on the conversion.

  FIG. 9 is a graph showing the pulsation waveform measured by the vascular pulse wave measurement system of FIG. 1 converted into a blood pressure waveform. As is clear from FIG. 9, the display of the pulse wave waveform of FIG. 9 can be obtained by converting the output voltage waveform into a blood pressure waveform.

  FIG. 10 is a graph showing the operation of processing the pulsation waveform using the moving average method in the vascular pulse wave measurement system of FIG. In FIG. 10, it is a figure which shows a mode that a smooth pulsation waveform is produced | generated using the moving average method from the raw data of the pulse wave voltage obtained by the vascular pulse wave measurement system. In FIG. 10A, the horizontal axis represents time and the vertical axis represents pulse wave voltage, and the state of change of the pulse wave voltage at each sampling time is shown. In FIG. 10B, the horizontal axis is time, and the origin position and the like are aligned with FIG. The vertical axis represents the moving average value b of the data at each sampling time in FIG. For example, the moving average value is set for five data. In this case, if the raw data of the pulse wave voltage at the sampling time i is ai, the moving average value bi at the sampling time i can be calculated using the following equation (2).

b = (ai-4 + ai-3 + ai-2 + ai-1 + ai) / 5 (2)

  That is, since the moving average value bi can be calculated as soon as the sampling data ai is acquired, real-time processing is possible. Note that the number of data used for the moving average need not be five.

  11A is a graph showing an example of various signal waveforms at the time of a certain person's awakening measured by the vascular pulse wave measurement system of FIG. 1, and FIG. 11B is a vascular pulse wave measurement of FIG. It is a graph which shows an example of the various signal waveforms at the time of apnea of a certain subject measured by the system.

In FIG. 11A, each measurement waveform at awakening is as follows.
(A) R-EOG A1: An electrooculogram measured by a known electrooculometer.
(B) Chin-Ref: The amount of jaw displacement measured by a known jaw movement measuring device.
(C) Electrocardiogram: An electrocardiogram waveform measured by a known electrocardiograph.
(D) Electromyogram: EMG waveform measured by a known electromyograph.
(E) Snoring: A snoring sound measured by a small microphone.
(F) Respiration waveform: a respiration waveform when the pressure sensor detects a change in pressure under the body accompanying the respiration of the measurement subject and measures the respiration waveform.
(G) SpO2: blood oxygen saturation measured by a known pulse oximeter.
(H) This system: a pulse wave waveform measured by the blood vessel pulse wave measurement system according to this embodiment.

In FIG.11 (b), each measurement waveform at the time of apnea is as follows.
(A) R-EOG A1: An electrooculogram measured by a known electrooculometer.
(B) Chin-Ref: The amount of jaw displacement measured by a known jaw movement measuring device.
(C) Electrocardiogram: An electrocardiogram waveform measured by a known electrocardiograph.
(D) Electromyogram: EMG waveform measured by a known electromyograph.
(E) Snoring: A snoring sound measured by a small microphone.
(F) Respiration temperature sensor: Respiration temperature measured by a temperature sensor provided at the mouth.
(G) Respiratory pressure: This is a respiratory pressure waveform when the pressure sensor detects a change in pressure under the body accompanying the breathing of the measurement subject and measures the respiratory waveform.
(H) Thoracic variation: Thoracic variation measured by a stress sensor that measures changes in the subject's thorax.
(I) Abdominal variation: An abdominal variation measured by a stress sensor that measures a change in the abdomen of the measurement subject.
(J) SpO2: blood oxygen saturation measured by a known pulse oximeter.
(K) This system: a pulse wave waveform measured by the blood vessel pulse wave measurement system according to this embodiment.

  The data of FIG. 11 measured by the vascular pulse wave measurement system according to the present embodiment includes a lot of information that has not been understood by conventional measurement apparatuses. In FIG. 11 (a), while normal REM sleep is in progress, there are two wakefulness responses in the recorded 120 seconds, and the pulse pressure rises a little at the start of the wakefulness response, and then shows a sharp drop. ing. Increased sympathetic nerve activity due to arousal response, temporary increase in peripheral vascular resistance, and subsequent decrease in pulse pressure due to reflex vasodilation were observed, and changes in pulse pressure in normal sleep are synchronized with arousal response on EEG it is conceivable that. This is considered to enable sleep evaluation with a small vascular pulse wave measurement system that does not measure brain waves.

  In FIG. 11B, in a typical series of apnea, forced breathing-wakefulness reaction, and hyperpnea, a small cycle fluctuation synchronized with the forced breathing during apnea is observed (the fluctuation is small). Therefore, it can be seen that the pulse pressure gradually increases until the end of apnea. Thereafter, the pulse pressure drops rapidly with awakening reaction, resumption of breathing and hyperventilation. Perhaps the patient's daytime resting blood pressure is at a stable level after this drop, and the increase in blood pressure during apnea is due to excessive increase in sympathetic nerve activity due to apnea. Among the patients examined, some patients had peak systolic blood pressure 228. Therefore, in the case of patients with apnea syndrome, it is considered that special circulatory dynamics during sleep related to the onset of circulatory system diseases in which complication frequency is a problem can be evaluated.

  From the graphs of the pulse waveform shown in FIGS. 11A and 11B, the maximum blood pressure value Pmax rises more slowly than when apnea, and then repeats that during REM awakening. I understand. It can also be seen that during apnea, the maximum blood pressure value Pmax rises earlier than when REM awakens, then falls and repeats.

  FIG. 12A is a diagram illustrating a change in the maximum blood pressure value Pmax during awakening, and FIG. 12B is a diagram illustrating a change in the maximum blood pressure value Pmax during apnea. As is apparent from the model diagrams of the maximum blood pressure value Pmax in FIGS. 12A and 12B, the change period Tar of the maximum blood pressure value Pamx at the time of REM awakening is longer than that at the time of apnea, and the origin S It can be seen that the rising inclination angle αar of the maximum blood pressure value Pmax at the time of REM awakening is smaller than that at the time of apnea. Based on these findings and clinical trials, the flowchart of the sleep state determination process of FIG. 15 was created.

  FIG. 13 shows the blood pressure executed by the blood pressure value calibration processing module 52 of the device controller 50 of FIG. 1 for calibrating the maximum blood pressure value and the minimum blood pressure value using the same principle as the cuff compression method according to the prior art. It is a flowchart which shows a value calibration process.

  In FIG. 13, first, initial setting control signals Sc1 and Sc2 are output to the stepping motors M1 and M2. Next, in step S11, a pulse wave signal is detected using the MEMS pressure sensor 30, and a time period Tint (see FIG. 8A) of two minimum voltage values adjacent to each other in time of the pulse wave signal is calculated. In step S12 It is determined whether or not the time period Tint is within a predetermined threshold range (that is, whether or not a pulse wave signal is detected). If YES, the process proceeds to step S13, whereas if NO Returns to step S11. Here, the predetermined threshold range of the time period Tint is a determination range of whether or not a pulse wave signal is detected, and the threshold range is an experience value, for example, 0.2 seconds ≦ Tint ≦ 2 seconds. It is. If the time period Tint is within the threshold range, it is determined that a pulse wave has been detected. In step S13, it is determined that the pulse wave of the person to be measured 6 has been detected, and pressure increase control signals Sc1 and Sc2 are output to the stepping motors M1 and M2 in order to increment by a predetermined differential pressure. In step S14, it is determined whether or not the time period Tint is within a predetermined threshold range (that is, whether or not a pulse wave signal is detected). If NO, the process proceeds to step S15. On the other hand, if YES, the process returns to step S13.

  In step S15, it is determined that the pulse wave of the person to be measured 6 is no longer detected, and the maximum voltage value within one cycle period of the pulse wave signal before the sampling timing immediately before the sampling timing that is no longer detected is determined. The maximum blood pressure value voltage is stored in the internal memory 50m, and the detected pressure value of the MEMS pressure sensor 30 is stored in the internal memory 50m as the maximum blood pressure value. In step S16, pressure decrease control signals Sc1, Sc2 are output to the stepping motors M1, M2 in order to decrement by a predetermined differential pressure. Next, in step S17, it is determined whether or not the time period Tint is within a predetermined threshold range (that is, whether or not a pulse wave signal is detected). If YES, the process proceeds to step S18. On the other hand, if NO, the process proceeds to step S16. In step S18, it is determined that the pulse wave of the person to be measured 6 has been detected, and the minimum voltage value within one cycle period of the pulse wave signal immediately after the detected sampling timing is stored in the internal memory 50m as the minimum blood pressure value voltage. At the same time, the detected pressure value of the MEMS pressure sensor 30 is stored in the internal memory 50m as the minimum blood pressure value. Further, in step S19, as described with reference to FIG. 8C, based on the maximum blood pressure value voltage stored in the internal memory 50m, the corresponding maximum blood pressure value and the minimum blood pressure value voltage, and the corresponding minimum blood pressure value. Then, a conversion formula (or blood pressure conversion table) indicating conversion from the voltage value to the blood pressure value is generated using the linear approximation method, and is stored in the internal memory 50m, and the processing ends.

  Although the blood pressure value calibration process of FIG. 13 is executed using, for example, the pulse wave and pressure detection application device 20 of FIG. 2, the present invention is not limited to this, and may be executed using only the MEMS pressure sensor 30. . In this case, in step S13, it is determined that the pulse wave of the person to be measured 6 has been detected, and the MEMS pressure sensor 30 is used with the fingertip 9 against a human subject such as a subject without using the 5-joint link mechanism 21 that is a pressure application mechanism. A message instructing to press the top of the LCD is displayed on an LCD display (not shown) or the like. At this time, the person presses with the fingertip 9. In step S16, it is determined that the pulse wave of the person to be measured 6 is no longer detected, and the stress at the fingertip 9 is relaxed against a human subject such as a subject without using the 5-joint link mechanism 21 which is a pressure application mechanism. A message for instructing to decrease is displayed on an LCD display (not shown) or the like. At this time, the human releases the pressure on the fingertip 9. Thus, instead of the five-joint link mechanism 21 that is a pressure application mechanism, a human fingertip 9 such as a person to be measured can be substituted.

  In the vascular pulse wave measurement system, by using the apparatus of only the pulse wave and pressure detection application device 20 or the MEMS pressure sensor 30 of FIG. 2 described above and the blood pressure value calibration process of FIG. Calibration can be performed so that the blood pressure value voltage of the vascular pulse wave signal is converted into a blood pressure value with extremely simple calibration and high accuracy compared to the technology.

  FIG. 14 is a flowchart showing blood vessel pulse wave measurement executed by the blood vessel pulse wave measurement processing module 51 of the apparatus controller 50 of FIG.

  14, in step S21, for example, pulse waveform data for the latest five cycles (referred to as voltage value data from the A / D converter 33) is stored in the buffer memory, and in step S22, the pulse waveform data is stored. It is determined whether or not the value is within the calculation range. If YES, the process proceeds to step S23. If NO, the process returns to step S21. In step S23, low-pass filter processing for removing high-frequency noise is performed on the pulse waveform data for the above five cycles, and in step S24, refer to FIG. 10 for the pulsation waveform data after low-pass filter processing. The moving average process using the moving average method described above is executed, and the blood pressure measurement process by converting the voltage value into the blood pressure value using the conversion formula is executed in step S25. Further, in step S26, pulse wave display data is generated using the converted blood pressure value, the pulse wave (real time) is displayed on the display unit 60, and the pulse, maximum blood pressure value, and minimum blood pressure value are calculated and displayed. 60. In step S27, it is determined whether or not the measurement is completed. If YES, the process ends. If NO, the process returns to step S21.

  FIG. 15 is a flowchart showing sleep state determination processing executed by the sleep state determination processing module 53 of the device controller 50 of FIG.

  In FIG. 15, for example, pulse waveform data for the latest 21 cycles is stored in the buffer memory in step S31, and the converted maximum blood pressure value based on the pulse waveform data for 21 cycles stored in step S32 Using the minimum blood pressure value, the maximum blood pressure values Pmax (1) to Pmax (21) for 21 cycles and the minimum blood pressure values Pmin (1) to Pmin (21) for 21 cycles are calculated, and time t (1) to t t (21) is stored in the buffer memory. Next, in step S33, the following parameters are calculated for 21 periods (n = 1, 2,..., 21).

Slope of maximum blood pressure value Pmax with respect to time (period of 20 cycles)
P ′ = (Pmax (21) −Pmax (1)) / (t (21) −t (1)) (3)

Pmaxave = average value (Pmax (1) to Pmax (20)) (4)

Pulse pressure Pp = Pmax (20) −Pmin (20) (5)

  Next, in step S34, it is determined whether or not Pmax (21) has decreased by 20% or more with respect to Pmaxave (hereinafter referred to as condition 1). If YES, the process proceeds to step S35, but if NO. Returns to step S31. Next, in step S35, it is determined whether or not the pulse pressure Pp has decreased by 20% or more with respect to the average value Pmaxave (hereinafter referred to as condition 2). If YES, the process proceeds to step S36 while NO. If so, the process returns to step S31. In step S36, steps S21 to S25 are shifted and executed for each of the three periods, and conditions 1 and 2 are determined to determine whether or not three periods or more are satisfied continuously. If YES, the process proceeds to step S37. If NO, the process returns to step S31. In step S37, it is determined whether or not the inclination P ′> P′th (a predetermined threshold value, which is a threshold value for identifying the inclination angle αar and the inclination angle αsa in FIG. 12). If YES, the process proceeds to step S38. If NO, the process proceeds to step S39. In step S38, the subject is determined to be in the “apnea state” and displayed on the display unit 60, and the process proceeds to step S40. On the other hand, in step S39, the person to be measured is determined to be in the “wake state” and displayed on the display unit 60, and the process proceeds to step S40. In step S40, it is determined whether or not the measurement is finished. If YES, the process ends. If NO, the process returns to step S31.

  In the sleep state determination process of FIG. 15, “20 cycles”, “21 cycles”, “20%”, “3 cycles”, etc., such as the number of processing data and decision branches, are examples, and the present invention is not limited to this. For example, “20%” is a predetermined threshold ratio for determination.

  In the above embodiment, each of the above processes may be realized by software, or a part of them may be realized by a hardware circuit.

  In the above embodiment, the maximum blood pressure value and the minimum blood pressure value are calibrated by the cuff compression method, but the present invention is not limited to this, and other calibration methods may be used.

  In the above embodiment, the 5-joint link mechanism 21 is used as a pressure application mechanism that applies pressure to the blood vessel through the skin. However, the present invention is not limited to this, and a known pressure actuator or the like may be used. Good. These modifications will be described below.

  FIG. 16A is a longitudinal sectional view showing a configuration of a pulse wave and pressure detection application device 20A including a pressure actuator 36 and a MEMS pressure sensor 30 according to a first modification of the present invention. In FIG. 16A, a pulse wave and pressure detection application device 20A includes a pressure sheet sensor 35 that detects pressure and pulse wave on the blood vessel 8 of the measurement subject, and a pressure actuator 36 that applies pressure to the blood vessel 8 of the measurement subject. Are provided in a predetermined casing 37 using a filler 38 such as urethane. Here, preferably, the MEMS pressure sensor 30 and the pressure sheet sensor 35 are provided in direct contact with each other. Thereby, the stress of the pressure actuator 36 is applied to the blood vessel 8 through the MEMS pressure sensor 30 and the skin of the measurement subject in the downward direction 36f from the position 36a in FIG. 16A.

  In the first modified example, in the blood pressure value calibration process of FIG. 13, the process of step S10 is deleted, and in step S13, a pressure increase control signal Sc for increasing by a predetermined pressure width is sent from the apparatus controller 50 to the pressure actuator 36. Output to. In step S16, a pressure lowering control signal Sc for lowering by a predetermined pressure width is output from the device controller 50 to the pressure actuator 36. Other processes are the same as those in FIG.

  FIG. 16B is a longitudinal sectional view showing a configuration of a pulse wave and pressure detection applying device 20B including a MEMS pressure sensor 30 that is pressed by a human fingertip such as a subject according to a second modification of the present invention. In the pulse wave and pressure detection application device 20B of FIG. 16B, instead of the pressure actuator 36 of FIG. 16A, the MEMS pressure from the upper central portion 36a of the casing 37 in the lower direction 9a of the figure by a human fingertip 9 such as a subject. A stress 9f is applied to the blood vessel 8 through the sensor 30 and the skin of the measurement subject.

  FIG. 17 is a side view showing a configuration of a variation of the pulse wave and pressure detection application device 20 of FIGS. 2 and 3 according to a third variation of the present invention. In the embodiment of FIGS. 2 and 3, the MEMS pressure sensor 30 is attached to the lower tip of the joint J3, and pressure is applied to the blood vessel 8 such as the wrist in the −Y direction by the 5-joint link mechanism 21. . On the other hand, in the third modified example of FIG. 17, the five-joint link mechanism 21 is arranged upside down, and the MEMS pressure sensor 30 is placed at the lower end of the joint J3 (the opposite side to FIGS. 2 and 3). The joint J3 may be applied to the blood vessel 8 such as the wrist in the direction opposite to that in FIGS. 2 and 3 (the −Y direction in FIG. 17). This modification has an advantage that it can be fixed to, for example, a wrist using a cuff on the fixed end side of the five-joint link mechanism 21.

  FIG. 18A is a longitudinal sectional view showing a configuration of a pulse wave and pressure detection applying device 20C including a pressure actuator 36 and a MEMS pressure sensor 30 according to a fourth modification of the present invention. FIG. 18A is a modification of FIG. 16A. In FIG. 16A, a MEMS pressure sensor 30 is provided directly below the pressure actuator 36 in a casing 37 filled with a filler 38, and the pressure actuator 36 is connected to the MEMS pressure sensor 30 via the MEMS pressure sensor 30. The pressure 36f is applied to the blood vessel 8, and the MEMS pressure sensor 30 directly detects the pressure 36f from the pressure actuator 36. On the other hand, in the fourth modification of FIG. 18A, the MEMS pressure sensor 30 is placed in parallel with the pressure actuator 36 in a gel sheet 37A filled with the gel 38A (referred to as a bag-shaped sheet in which the gel 38A can be incorporated). A pressure 36f is applied to the blood vessel 8 from the pressure actuator 36 through the gel 38A or directly, and the MEMS pressure sensor 30 applies a part of the pressure 36fa from the pressure actuator 36 to the gel 38A. You may detect indirectly via. In this case, with respect to the partial pressure, how much of the pressure 36f is distributed and applied is measured and calibrated in advance.

  FIG. 18B is a longitudinal sectional view showing a configuration of a pulse wave and pressure detection applying device 20D including a MEMS pressure sensor 30 that is pressed by a human fingertip such as a subject according to a fifth modification of the present invention. FIG. 18B is a modification of FIG. 16B. In FIG. 16B, a MEMS pressure sensor 30 is provided in a casing 37 filled with a filler 38, and the pressure 9f is applied to the blood vessel 8 from the fingertip 9 through the pressing portion 37a. The MEMS pressure sensor 30 directly detects the pressure 9f from the fingertip 9. On the other hand, in the fifth modified example of FIG. 18B, a MEMS pressure sensor 30 is provided in the vicinity of the gel sheet 37A filled with the gel 38A, not directly below the pressing portion 37a, and the fingertip 9 passes through the gel 38A. Alternatively, the pressure 9f may be directly applied to the blood vessel 8, and the MEMS pressure sensor 30 may indirectly detect the partial pressure 9fa of the pressure 9f from the pressure actuator 36 via the gel 38A. In this case, with respect to the partial pressure, how much of the pressure 36f is distributed and applied is measured and calibrated in advance.

Second embodiment.
FIG. 19 is a perspective view when the pulse wave and pressure detection application device 20E used in the blood pressure measurement device according to the second embodiment of the present invention is attached to the radial artery portion 7 of the wrist. In FIG. 19, the pulse wave and pressure detection application device 20E
(1) A MEMS pressure sensor 30 that includes the five-joint link mechanism 21 according to the first embodiment and measures a vascular pulse wave signal;
(2) Pressure value when stress is applied to the radial artery portion 7 of the wrist by the five-joint link mechanism 21 provided in the vicinity of the MEMS pressure sensor 30 and calibrated in advance and controlled by the device controller 50 Calibration pressure sensor (for example, constituted by a MEMS pressure sensor, a strain pressure sensor, etc.) 39, and in the second embodiment, a blood pressure measurement process using these two pressure sensors 30 and 39. It is characterized by performing. Here, the 5-joint link mechanism 21 is a pressure application mechanism capable of controlling the pressure value to be applied at a predetermined pressurization speed or pressure reduction speed, and the pressure value is controlled by the device controller 50. Other configurations are the same as those of the first embodiment. The arrangement of the calibration pressure sensor 39 may be configured so that the pressure can be detected directly or indirectly (similar to FIG. 18A) as long as the stress pressed by the five-joint link mechanism 21 can be detected.

  FIG. 20 is a timing chart of blood pressure measurement processing executed by the blood pressure measurement device of FIG. FIG. 21 is a flowchart of blood pressure measurement processing executed by the device controller 50 (FIG. 1) of the blood pressure measurement device of FIG. Hereinafter, the blood pressure measurement process according to the second embodiment will be described with reference to FIGS. 20 and 21. In FIG. 20, the upper blood vessel pulse wave signal indicates the pulse wave and the output voltage (hereinafter referred to as pulse wave voltage value) Vout from the MEMS pressure sensor 30 of the pressure detection applying device 20E, and the lower pulse pressure is The pulse pressure value Ppre from the calibration pressure sensor 39 is shown.

  Referring to FIGS. 20 and 21, in step S41 from time t11, the maximum pulse wave voltage value Vmax and the minimum pulse wave are obtained based on the pulse wave voltage value Vout by executing a pre-measurement process for a steady pulse wave. The voltage value Vmin, steady voltage amplitude Vd (= Vmax−Vmin) and one beat time T1 (cycle of the vascular pulse wave signal) are measured and stored in the internal memory 50m. Here, it is preferable to increase the accuracy of each of these values by measuring an average value for a plurality of vascular pulse wave signals. Next, in step S42 from time t12, the five-joint link mechanism 21 is used to press the radial artery portion 7 of the wrist to a predetermined pressurization speed (the slope of the pressure value during pressurization with respect to time. Also, with respect to time. The pressure value slope at the time of decompression is pressurized at a decompression speed), and the pulse wave disappears at time t13 (when the voltage value Vout of the vascular pulse wave signal becomes substantially zero, or the vascular pulse wave signal The pressurization process (S42) is executed while the determination process of step S43 is executed until the period Tint of the minimum voltage value Vmin is not within the predetermined threshold. If YES in step S43 at time t13, the pressurization process is stopped, and then the pressure is reduced from the predetermined maximum blood pressure setting value Pmaxset at the predetermined pressure reduction speed Gr1 using the five-joint link mechanism 21. At this time, it is preferable to perform step pressure reduction (referred to as a step pressure reduction method) stepwise rather than linear pressure reduction (referred to as a linear pressure reduction method). Here, preferably, after the pressure value is set to a constant value in a time period of one beat time (or an integral multiple thereof), the pressure is reduced successively, and the pulse wave of the vascular pulse wave signal is resumed at time t14 (YES in S45). When the vascular pulse wave signal voltage value Vout substantially exceeds 0 and becomes equal to or higher than a measurable unit voltage such as 0.01 V, or the minimum voltage value Vmin of the vascular pulse wave signal has a predetermined threshold Tint. The pulse pressure value Ppre from the calibration pressure sensor 39 immediately before that is measured as the maximum blood pressure value Pmax and stored in the internal memory 50m (S46). Therefore, since the maximum blood pressure value Pmax is measured with the pressure value fixed for a predetermined period by the step decompression method, the accuracy of measurement of the maximum blood pressure value Vmax can be improved as compared to linear decompression continuously.

  After step S45, the decompression process of step S47 is started, and decompression is performed at a predetermined decompression speed Gr2 by, for example, the linear decompression method (the step decompression method may be used, but the linear decompression method can shorten the required time). The decompression process is performed for a time period of about 70% to 80% of the time when considering the decompression speed when decompressing from the maximum blood pressure value Pmax to the minimum blood pressure value Pmin. At the subsequent time t15, the process is changed to the step depressurization method at the depressurization speed Gr3 and the determination process of step S48 is performed. In step S48, whether or not the pulse wave voltage value Vout of the vascular pulse wave signal has reached the steady voltage amplitude Vd (actually, whether or not Vout has entered Vd ± ΔVd: where ΔVd is It is a minute range.) If “YES” in the step S48, it is determined that the minimum blood pressure is reached at that time, and the pulse pressure value Ppre from the calibration pressure sensor 39 is measured as the minimum blood pressure value Pmin and stored in the internal memory 50m (S49). As described above, the maximum blood pressure value Pmax and the minimum blood pressure value Pmin can be measured and displayed on the display unit 60, for example. Therefore, since the minimum blood pressure value Pmin is measured while the pressure value is fixed for a predetermined period by the step pressure reduction method, the measurement accuracy of the minimum blood pressure value Vmin can be improved as compared with linear pressure reduction continuously. Further, in step S50, the calibration value a is calculated and set using the following equation, and stored in the internal memory 50m (FIG. 1) of the apparatus controller 50. By multiplying the pulse wave voltage value Vout by the calibration value a, the blood pressure value can be displayed in real time.

a = (Pmax−Pmin) / (Vmax−Vmin) (6)

In the decompression process of FIG. 20, the decompression speeds Gr1, Gr2, and Gr3 are set in a relationship of Gr2> Gr1 = Gr3, so that the minimum blood pressure value Pmin can be measured earlier, and the entire blood pressure measurement time can be shortened. Here, the decompression speeds Gr1 and Gr3 may be set to be different from each other, or may be set to Gr1 = Gr2 = Gr3. Furthermore, it is preferable that the decompression speeds Gr1 and Gr3 are changed and set according to the length of one beat time T1 of the vascular pulse wave signal as follows.
(1) When the one beat time T1 becomes longer, the decompression speed is reduced.
(2) When the 1 beat time T1 is shortened, the decompression speed is increased.
That is, the decompression speed is set so that the relationship between the one beat time T1 and the decompression speed is inversely proportional.

Actually, for example, predetermined threshold times T1th1, T1th2 (T1th1> T1th2) and predetermined decompression speed values Grp1, Grp2, Grp3 (Grp1 <Grp2 <Grp3) are set,
(A) When T1> T1th1, the decompression speed is set to a predetermined value Grp1.
(B) When T1th1 ≧ T1 ≧ T1th2, the decompression speed is set to a predetermined value Grp2.
(C) When T1 <T1th2, the decompression speed is set to a predetermined value Grp3.

  As described above, the maximum blood pressure value Pmax and the minimum blood pressure value Pmin can be measured with higher accuracy than in the prior art by setting the decompression speed according to the length of one pulse time T1 of the vascular pulse wave signal. .

  In the blood pressure measurement process of FIG. 20, when the device controller 50 no longer measures the vascular pulse wave signal by applying stress to the blood vessel via the calibration pressure sensor 39 and the skin by the 5-joint link mechanism 21 and pressurizing it. When pressurization is stopped and then the pressure is reduced, and then the vascular pulse wave signal is measured, the pressure value of the calibration pressure sensor 39 immediately before that is measured as the maximum blood pressure value. When a vascular pulse wave signal having a voltage value is measured, the pressure value of the calibration pressure sensor 39 at that time may be measured as the minimum blood pressure value. Here, the preliminary measurement process (S41) and the calculation and setting process (S50) of the calibration value a may not be executed.

  FIG. 22 is a block diagram showing a configuration of a circuit for generating a decompression step instruction signal from a vascular pulse wave signal in the blood pressure measurement device of FIG. In the blood pressure measurement process of FIG. 20, in the decompression process in steps S44 and S47, decompression by two step decompression methods is executed. At this time, the decompression cycle of the step decompression is synchronized with the cycle of the vascular pulse wave signal. The maximum blood pressure value Pmax and the minimum blood pressure value Pmin can be measured with higher accuracy than in the prior art. Specifically, after the output voltage Vout of the vascular pulse wave signal from the pulse wave and pressure detection applying device 20E is amplified by the voltage amplifier 32, a clock signal synchronized with the vascular pulse wave signal is reproduced by the clock reproduction circuit 71. This is used as a decompression step signal. Synchronizing with the decompression step signal, the stepping motors M1 and M2 of the five-joint link mechanism 21 are operated to perform decompression processing in steps S44 and S47.

  In the blood pressure measurement device described above, step pressure reduction is performed when measuring the maximum blood pressure value Pmax and when measuring the minimum blood pressure value Pmin. However, the present invention is not limited to this, and step pressure reduction may be performed for at least one of them.

Modified example of the second embodiment.
FIG. 23 is a timing chart of blood pressure measurement processing executed by the blood pressure measurement device according to the modification of the second embodiment. FIG. 24 is a flowchart of the blood pressure measurement process executed by the device controller 50 (FIG. 1) of the blood pressure measurement device according to the modification of the second embodiment. The blood pressure measurement process according to the modification of the second embodiment differs from the blood pressure measurement process according to the second embodiment of FIGS. 21 and 22 in the following points.
(1) Instead of the preliminary measurement process in step S41, a preliminary measurement calculation process is performed in step S41A. That is, using the MEMS pressure sensor 30 in which the calibration value a is calculated in advance (or the pressure value is calibrated in advance), the maximum pulse wave voltage value Vmax, the minimum pulse wave voltage value Vmin, and the steady voltage amplitude Vd (= In addition to (Vmax−Vmin) and one beat time T1 (cycle of the vascular pulse wave signal), a maximum pressure value Pmaxpre and a minimum pressure value Pminpre are calculated. Next, the processes in steps S42 to S46 are executed in the same manner as in FIG.
(2) Instead of steps S47 to S50, the processes of steps S51 and S50 are executed. In step S51, the minimum blood pressure value Pmin is calculated based on the maximum blood pressure value Pmax. Note that the processing in step S50 is executed in the same manner as in FIG.
Hereinafter, the differences will be described in detail.

  In step 41A, the maximum pulse wave voltage value Vmax, the minimum pulse wave voltage value Vmin, and the steady voltage amplitude Vd using the MEMS pressure sensor 30 in which the calibration value a is calculated in advance (or the pressure value is calibrated in advance). After measuring (= Vmax−Vmin) and one beat time T1 (cycle of the vascular pulse wave signal), the maximum pressure value Pmaxpre and the minimum pressure value Pminpre are calculated using the following equations. The calibration value a may be the value calculated in step S50 of the prior blood pressure measurement process, or the calibration value a calculated in the prior calibration process may be used.

Pmaxpre = a × Vmax (7)
Pminpre = a × Vmin (8)

  In step S51, based on the maximum blood pressure value Pmax measured in step S46 and the maximum pressure value Pmaxpre and the minimum pressure value Pminpre calculated in step S41A, the blood pressure offset value Poffset and the minimum blood pressure value are calculated using the following equations. Pmin is estimated and calculated, and the measured maximum blood pressure value Pmax and the estimated and calculated minimum blood pressure value Pmin are output to the display unit 60 and displayed.

Pmin = Pminpre + Poffset (9)
Poffset = Pmax−Pmaxpre (10)

  According to the modification of the second embodiment configured as described above, since the estimation calculation can be performed without measuring the minimum blood pressure value Pmin, the maximum blood pressure value Pmax and the minimum blood pressure can be calculated faster than in the second embodiment. The value Pmin can be measured. Note that the maximum blood pressure value Pmax can be measured with high accuracy by setting the decompression step and decompression speed in the decompression process of step S44 in the same manner as in the second embodiment.

Third embodiment.
FIG. 25 is a perspective view when the pulse wave and pressure detection application device 20F used in the blood pressure measurement device according to the third embodiment of the present invention is attached to the radial artery portion 7 of the wrist. In FIG. 25, the blood pressure measurement device according to the third embodiment uses an optical probe circuit 120 to measure a vascular pulse wave signal, as compared with the second embodiment of FIG. It is said. Other configurations are the same as those of the second embodiment and the modification thereof, and the blood pressure measurement process is executed in the same manner.

  FIG. 26 is a side view showing the configuration of the reflective optical probe 112 in the optical probe circuit 120 of FIG. In FIG. 26, the optical probe 112 is configured by arranging a light emitting element 114 and a light receiving element 116 on a circuit board 118 in a predetermined holding portion 113. The holding unit 113 is a member that incorporates a circuit board 118 and that projects the light emitting part of the light emitting element 114 and the light detecting part of the light receiving element 116 on the surface, and is formed by molding an appropriate plastic material, for example. As the light emitting element 114, a light emitting diode (LED) can be used. For example, an infrared LED is used. As the light receiving element 116, a photodiode or a phototransistor is used.

  The light emitting element 114 and the light receiving element 116 are preferably arranged close to each other, but a structural device such as a light shielding wall is provided so that light from the light emitting element 114 does not directly enter the light receiving element 116. It is preferable to do. Alternatively, lenses may be provided in the light emitting element 114 and the light receiving element 116 to enhance directivity. In the example of FIG. 26, one light emitting element 114 and one light receiving element 116 are provided, but a plurality of light emitting elements 114 and a plurality of light receiving elements 116 may be provided. Further, the light receiving element 116 may be disposed so as to be surrounded by a plurality of light emitting elements 114. The optical probe 112 is attached to a site suitable for detecting the pulse of the blood vessel 8 of the measurement subject 6 with an appropriate band, tape, or the like not shown. FIG. 26 shows a state in which the optical probe 112 is attached to the radial artery portion 7 of the wrist. The optical probe 112 may be attached to this part.

  FIG. 27 is a circuit diagram showing the configuration of the optical probe circuit 120 of FIG. In FIG. 27, the optical probe circuit 120 includes a drive circuit for the light emitting element 114 and a detection circuit for the light receiving element 116, and outputs an output signal from the detection circuit directly to the drive circuit for synchronous feedback. To form a self-excited oscillation circuit.

  As a driving circuit for the light emitting element 114, a configuration in which the light emitting element 114 and the driving transistor 124 are connected in series between the power supply voltage Vcc and the ground and the base that is the control terminal of the driving transistor 124 is used as a predetermined bias condition is used. It is done. In this configuration, when the input signal to the base of the drive transistor 124 becomes high, the drive transistor 124 is turned on and a drive current flows through the light emitting element 114. Thereby, the light emitting element 114 emits light, and the light is emitted toward the blood vessel 8 through the skin. As the detection circuit for the light receiving element 116, a configuration in which the load resistor 122, the transistor 123, and the light receiving element 116 are connected in series between the positive power supply voltage Vcc and the negative power supply voltage −Vcc is used. . In this configuration, a light current is generated in the light receiving element 116 when the light receiving element 114 receives the reflected light from the blood vessel 8 irradiated by the light of the light emitting element 114 through the skin. The magnitude of the photocurrent is output as a signal (output voltage signal) of the output voltage Vout corresponding to the magnitude of the current flowing through the load resistor 122. Since the signal of the output voltage Vout is a self-excited oscillation signal, it is an AC signal.

  The output voltage signal from the optical probe circuit 120 constituting the self-excited oscillation circuit is output to the device controller 50 via the amplifier 30 and the A / D converter 31 as in FIG. As described above, when light is emitted from the light emitting element 114 by the blood vessel 8 (more precisely, for example, the blood vessel wall of the blood vessel filled with blood containing oxygenated hemoglobin), and the light receiving element 116 receives the reflected light from the blood vessel 8. The output voltage signal from the optical probe circuit 120 is the propagation distance of light (the light emitted from the light emitting element 114 is received by the light receiving element 116). Therefore, when the blood vessel 8 changes due to pulsation, the output voltage Vout changes. That is, the output voltage Vout changes corresponding to the change in pulsation. To do.

  In the prior arts such as Patent Documents 1 to 3, since a large change in output voltage could not be obtained, the change in frequency was converted into a change in voltage to detect a change in pulsation. 27, as shown in FIG. 27, the output signal of the detection circuit in the optical probe circuit 120 is directly synchronously fed back as an input signal of the drive circuit and self-oscillated to generate a self-oscillation signal, and the output voltage Vout A pulsation waveform can be obtained very easily by controlling and setting so that the amplitude width (change amount) of the self-oscillation signal that is an AC signal is substantially maximized.

  In the blood pressure measurement device according to the third embodiment described above, the second blood pressure signal is measured using the optical probe circuit 120 and the pulse pressure is measured using the calibration pressure sensor 39. The blood pressure measurement process can be executed in the same manner as the embodiment and its modification. In particular, in the third embodiment, as compared with the prior art, step decompression and high-speed measurement in the decompression process (calculation and measurement of the minimum blood pressure Pmin based on the maximum blood pressure Pmax in the modification of the second embodiment) It has novelty and inventive step.

Modified examples of the second and third embodiments.
In FIG. 19, pressure is applied by the five-joint link mechanism 21 to the MEMS pressure sensor 30 of the pulse wave and pressure detection application device 20 </ b> E, but the present invention is not limited to this, and instead of the five-joint link mechanism 21. The pressure may be applied by the pressure actuator 36 as shown in FIG. 16A.

  In FIG. 25, pressure is applied by the five joint link mechanism 21 to the optical probe circuit 120 of the pulse wave and pressure detection applying device 20F, but the present invention is not limited to this, and the five joint link mechanism 21 is applied. Instead, pressure may be applied by the pressure actuator 36 as shown in FIG. 16A.

Differences between the prior art and the vascular pulse wave measurement system according to the present invention.
The blood vessel pulse wave measuring method according to the present invention includes a volume vibration method according to the prior art (for example, see Patent Document 5), a method using ultrasonic waves (for example, see Patent Document 6 and Non-Patent Document 1), and the like. Is a measurement method based on a completely different principle, and is a non-invasive measurement method called the “MEMS pressure sensor and Wheatstone bridge method”, which is a combination of the MEMS pressure sensor 30 and the Wheatstone bridge circuit 15. The present invention has the following specific effects.
(1) The present invention is not limited to the vibration of the vascular pulse wave, but the increase in sympathetic nerve activity due to arousal reaction and the temporary increase in peripheral vascular resistance, which could not be obtained by the noninvasive measurement method according to the prior art. Changes in baseline (voltage signal DC level) of blood pressure values (pulse signal waveform data) such as pulse pressure drop due to reflex vasodilation and excessive increase in sympathetic nerve activity due to apnea can be measured. The blood vessel pulse wave measurement system can be realized by using the pulse wave and pressure detection applying devices 20, 20A, 20B including the MEMS pressure sensor 30 having a simple configuration and extremely small size.
(2) Further, by using the data of the pulse wave waveform signal, it is possible to detect a respiratory abnormality such as an apnea condition with a simple configuration and high accuracy as compared with the prior art.
(3) Further, using the data of the pulse wave waveform signal, the blood pressure value voltage of the blood vessel pulse wave signal is calibrated so as to be converted into a blood pressure value with a very simple calibration and high accuracy as compared with the prior art. be able to.

  Non-Patent Document 1 describes the ultrasonic measurement of the intensity (Wave Intensity) of a vascular pulse wave in the arterial system. FIG. 2.44 shows the measurement using the ultrasonic echo tracking method in the human common carotid artery. The blood vessel diameter change waveform and the blood vessel waveform measured with the catheter tip pressure gauge are shown, and the relationship between the two is not completely similar in the whole cardiac cycle, but can be regarded as similar in a practically sufficient system. In particular, it is almost completely similar in the ejection period when the vascular pulse wave intensity (Wave Intensity) is defined. Also in the blood vessel pulse wave measuring method according to the present invention, a blood vessel diameter change waveform (blood vessel pulse wave) can be obtained using a light oscillation signal.

  As described above in detail, the blood vessel pulse wave measurement system according to the present invention can be used to measure the state of blood flowing through a blood vessel, such as blood pressure measurement, using a blood vessel pulsation waveform.

6 ... measured person,
7 ... radial artery,
9 ... fingertips,
10 ... blood vessel pulse wave measurement system,
11 ... DC voltage source,
12 ... MEMS sensor resistance,
15 ... Wheatstone bridge circuit,
20, 20A, 20B, 20C, 20D, 20E, 20F ... pulse wave and pressure detection application device,
21 ... 5 joint linkage mechanism,
22 ... Case,
22a, 22b ... bearing holes,
30 ... MEMS pressure sensor,
31-1 to 31-N: Unit sensor circuit,
32 ... Voltage amplifier,
33 ... A / D converter,
34 ... control signal line,
36 ... Pressure actuator,
37 ... Case,
37A ... Gel sheet,
38 ... filler,
38A ... Gel,
39 ... Calibration pressure sensor,
50: Device controller,
50m ... internal memory,
51. Blood vessel pulse wave measurement processing module,
52. Blood pressure value calibration processing module,
53 ... Sleep state determination processing module,
60 ... display section,
61, 62 ... Pulsation waveform display,
63 ... Display of blood vessel pulse wave measurement value,
71: Clock recovery circuit,
112 ... Optical probe,
113 ... holding part,
114 ... light emitting element,
116: light receiving element,
118 ... circuit board,
120 ... Optical probe circuit,
122 ... load resistance,
124 ... Driving transistor,
125 ... sensor controller,
126 ... Distance selection switch,
127: Element selection switch,
130: Amplifier,
J1-J5 ... joints,
L1-L4 ... link,
M1, M2 ... Stepping motors.

Claims (19)

A first pressure sensor that is provided through the skin on the blood vessel and detects a pressure change of the pulse wave flowing through the blood vessel and measures it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measuring device comprising control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The control means applies pressure to the blood vessel by applying pressure to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism and stops measuring the blood vessel pulse wave signal. When the vascular pulse wave signal is measured after stopping, the pressure value of the second pressure sensor immediately before that is measured as the maximum blood pressure value, and then the pressure value is further reduced and the voltage value of a predetermined steady pulse wave Measuring the pressure value of the second pressure sensor at that time as the minimum blood pressure value,
The pressure application mechanism includes four links that connect the five first to fifth uniaxial joints to which the uniaxial joints at both ends are fixed, and a pair of adjacent uniaxial joints among the five uniaxial joints. A five-joint link mechanism with
The first and second pressure sensors are provided at the third joint,
The measuring means moves the position of the third uniaxial joint by rotating the uniaxial joints at both ends, so that the five-joint link mechanism is moved from the third uniaxial joint to the first and second pressures. A blood pressure measurement device that applies a predetermined pressure to a blood vessel through a sensor and skin. The control means includes
(1) When the blood vessel pulse wave signal is measured, based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor, the maximum voltage value and the minimum voltage value in the pressure change of the pulse wave are A pre-measurement process of a stationary pulse wave for measuring one beat time;
(2) Next, when the pressure application mechanism no longer measures the blood vessel pulse wave signal by applying stress to the blood vessel via the second pressure sensor and the skin through the pressure application mechanism, pressurization is performed. Pressure treatment to stop,
(3) Next, a first depressurization process for depressurizing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined first depressurization rate;
(4) a first measurement process for measuring, as the maximum blood pressure value, the pressure value of the second pressure sensor immediately before the vascular pulse wave signal is measured in the first decompression process;
(5) Next, a second decompression process for decompressing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined second decompression rate;
(6) Next, a third pressure reduction process for reducing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined third pressure reduction rate;
(7) When a blood vessel pulse wave signal having a steady pulse wave voltage value in the prior measurement process is measured in the third decompression process, the pressure value of the second pressure sensor at that time is measured as the minimum blood pressure value. Performing a second measurement process,
At least the first and third pressure reduction rate blood pressure measuring apparatus according to claim 1, characterized in that it is set to be in inverse proportion to one beat time as the measurement. The control means is configured to control the pressure application mechanism so that the pressure value is reduced stepwise in a stepwise pressure reduction method in at least one of the first pressure reduction process and the third pressure reduction process. The blood pressure measuring device according to claim 2 , wherein the blood pressure measuring device is controlled. 4. The blood pressure measurement device according to claim 3 , wherein the control means executes pressure reduction in the step pressure reduction method in synchronization with the blood vessel pulse wave signal. A clock recovery circuit for recovering a clock from the vascular pulse wave signal;
5. The blood pressure measurement device according to claim 4 , wherein the control means executes pressure reduction in the step pressure reduction method in synchronization with the vascular pulse wave signal based on the regenerated clock. The blood pressure measurement device according to any one of claims 2 to 5 , wherein the second decompression speed is set to be faster than the first and third decompression speeds. Said control means, said second vacuum treatment, pressure value against time by the linear decompression method of claim 2-6, characterized in that for controlling the pressure application mechanism to vacuum linearly The blood pressure measurement device according to any one of the above. To the first and second pressure sensors of any one of claims 1-7, characterized in that the MEMS pressure sensor for detecting a pressure change in the pulse wave flowing through the blood vessel as a resistance value change The blood pressure measurement device described. The first pressure sensor is
An optical probe including a light emitting element that emits light to a blood vessel through the skin, and a light receiving element that receives reflected light from the blood vessel or transmitted light through the blood vessel through the skin;
A driving circuit for driving the light emitting element based on an input driving signal;
An optical sensor comprising an optical probe circuit including a detection circuit that converts the light received by the light receiving element into an electrical signal and outputs the electrical signal;
The blood pressure according to any one of claims 1 to 7 , wherein the second pressure sensor is a MEMS pressure sensor that detects a pressure change of a pulse wave flowing in the blood vessel as a resistance value change. measuring device. A first pressure sensor having a pressure value calibrated in advance and provided through the skin on the blood vessel to detect a pressure change of the pulse wave flowing in the blood vessel and measuring it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measuring device comprising control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The control means includes
(1) When the blood vessel pulse wave signal is measured, based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor, the maximum voltage value and the minimum voltage value in the pressure change of the pulse wave are And measuring the maximum pressure value and the minimum pressure value respectively corresponding to the maximum voltage value and the minimum voltage value based on the maximum voltage value, the minimum voltage value, and a predetermined calibration value. Processing,
(2) Next, when the pressure application mechanism no longer measures the blood vessel pulse wave signal by applying stress to the blood vessel via the second pressure sensor and the skin through the pressure application mechanism, pressurization is performed. Pressure treatment to stop,
(3) Next, a first depressurization process for depressurizing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined first depressurization rate;
(4) a first measurement process for measuring, as the maximum blood pressure value, the pressure value of the second pressure sensor immediately before the vascular pulse wave signal is measured in the first decompression process;
(5) A third measurement process for estimating and measuring a minimum blood pressure value based on the measured maximum blood pressure value, the maximum pressure value, and the minimum pressure value is performed. Blood pressure measurement device. The control means further measures one beat time in the pressure change of the pulse wave based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor,
11. The blood pressure measurement device according to claim 10, wherein the first pressure reduction rate is set to be inversely proportional to the measured one beat time. 12. The control device according to claim 10 , wherein the control means controls the pressure application mechanism in the first pressure reduction process so that the pressure value is lowered stepwise by the step pressure reduction method to perform the pressure reduction. The blood pressure measurement device described. The blood pressure measurement device according to claim 12 , wherein the control means executes the pressure reduction in the step pressure reduction method in synchronization with the blood vessel pulse wave signal. A clock recovery circuit for recovering a clock from the vascular pulse wave signal;
14. The blood pressure measurement apparatus according to claim 13 , wherein the control means executes pressure reduction in the step pressure reduction method in synchronization with the vascular pulse wave signal based on the regenerated clock. The said 1st and 2nd pressure sensor is a MEMS pressure sensor which detects the pressure change of the pulse wave which flows into the said blood vessel as resistance value change, Any one of Claims 10-14 characterized by the above-mentioned. The blood pressure measurement device described. Said pressure applying mechanism, any one of claims 1 to 15, characterized in that a pressure actuator to apply a predetermined pressure against the vessel via the first and second pressure sensors and skin The blood pressure measuring device according to one. The pressure application mechanism includes four links that connect the five first to fifth uniaxial joints to which the uniaxial joints at both ends are fixed, and a pair of adjacent uniaxial joints among the five uniaxial joints. A five-joint link mechanism with
The first and second pressure sensors are provided at the third joint,
The measuring means moves the position of the third uniaxial joint by rotating the uniaxial joints at both ends, so that the five-joint link mechanism is moved from the third uniaxial joint to the first and second pressures. The blood pressure measurement device according to any one of claims 10 to 15 , wherein a predetermined pressure is applied to the blood vessel through the sensor and the skin. A first pressure sensor that is provided through the skin on the blood vessel and detects a pressure change of the pulse wave flowing through the blood vessel and measures it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measurement method for a blood pressure measurement device comprising a control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The pressure application mechanism includes four links that connect the five first to fifth uniaxial joints to which the uniaxial joints at both ends are fixed, and a pair of adjacent uniaxial joints among the five uniaxial joints. A five-joint link mechanism with
The first and second pressure sensors are provided at the third joint,
The measuring means moves the position of the third uniaxial joint by rotating the uniaxial joints at both ends, so that the five-joint link mechanism is moved from the third uniaxial joint to the first and second pressures. Apply a predetermined pressure to the blood vessel through the sensor and the skin,
The control means includes
When pressure is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism to pressurize and the blood vessel pulse wave signal is not measured, the pressurization is stopped and then the pressure is reduced. Thereafter, when the vascular pulse wave signal is measured, the pressure value of the second pressure sensor immediately before that is measured as the maximum blood pressure value, and then the pressure is further reduced, and the vascular pulse wave having a predetermined steady-state pulse wave voltage value. When measuring a signal, the blood pressure measuring method characterized by performing the step which measures the pressure value of the 2nd pressure sensor at that time as a minimum blood pressure value. A first pressure sensor having a pressure value calibrated in advance and provided through the skin on the blood vessel to detect a pressure change of the pulse wave flowing in the blood vessel and measuring it as a voltage value of the blood vessel pulse wave signal;
A pressure application mechanism capable of controlling the pressure value to be applied;
Provided in the vicinity of the first pressure sensor, the pressure value is calibrated in advance, and the pressure value when the stress is applied to the blood vessel via the second pressure sensor and the skin by the pressure application mechanism is detected. A second pressure sensor that
A blood pressure measurement method for a blood pressure measurement device comprising a control means for measuring a maximum blood pressure value and a minimum blood pressure value based on the vascular pulse wave signal and the detected pressure value,
The control means includes
(1) When the blood vessel pulse wave signal is measured, based on the voltage value of the blood vessel pulse wave signal measured by the first pressure sensor, the maximum voltage value and the minimum voltage value in the pressure change of the pulse wave are And measuring the maximum pressure value and the minimum pressure value respectively corresponding to the maximum voltage value and the minimum voltage value based on the maximum voltage value, the minimum voltage value, and a predetermined calibration value. Processing,
(2) Next, when the pressure application mechanism no longer measures the blood vessel pulse wave signal by applying stress to the blood vessel via the second pressure sensor and the skin through the pressure application mechanism, pressurization is performed. Pressure treatment to stop,
(3) Next, a first depressurization process for depressurizing the pressure value of the stress to the blood vessel through the second pressure sensor and the skin by the pressure application mechanism at a predetermined first depressurization rate;
(4) a first measurement process for measuring, as the maximum blood pressure value, the pressure value of the second pressure sensor immediately before the vascular pulse wave signal is measured in the first decompression process;
(5) A third measurement process for estimating and measuring a minimum blood pressure value based on the measured maximum blood pressure value, the maximum pressure value, and the minimum pressure value is performed. Blood pressure measurement method.

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