JP2013106641A - Sphygmotachograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conveniently measure the blood flow of a subject.SOLUTION: A sphygmotachograph 10 includes blood flow measurement sections 20 (20A-20D) to be attached to the wrists and ankles of a subject X, and a controller 30. The blood flow measurement sections 20 (20A-20D) each have at least a radio communication device 40, an optical sensor section 50, a measurement control section 60 and a chargeable battery 70. The controller 30 is configured so as to be portable and compact, and has at least a radio communication device 80, a control section 90, a storage section 100 and a chargeable battery 110. The blood flow measurement sections 20 (20A-20D) each transmit the measured data of measured blood flow to the controller 30 via the radio communication device 40. The controller 30 compares each of the measurement data stored in the storage section 100 to execute ABI control processing and PWV control processing, and causes the storage section 100 to store inspection results.

Description

  The present invention relates to a blood flow pulse wave inspection apparatus, and more particularly to a blood flow pulse wave inspection apparatus that measures blood flow of a subject.

  For example, when arteriosclerosis occurs due to the deposition of cholesterol (lipid) on the arterial vessel wall, hardening of the blood vessel, and narrowing of the lumen of the blood vessel, the progression of arteriosclerosis is performed by an inspection device that examines blood pressure and pulse wave There is an inspection method for quantifying.

  In such an inspection apparatus, blood pressure is measured by wrapping a cuff for measuring the blood pressure of the wrist and ankle of the subject and reducing the pressure from the state in which the cuff is pressurized with air (see, for example, Patent Document 1). ).

  Then, a numerical value of ABI (Ankle Brachial Pressure Index) is obtained from the ratio of the blood pressure of the wrist and the blood pressure of the ankle (ankle / brachial blood pressure ratio), and the value of the ABI is included in any level (numerical range) of the evaluation criteria. It is possible to determine the progress of arteriosclerosis depending on whether or not. In general, when the test result of the ABI test is 0.9 <ABI value <1.3, it is determined as normal, and when the ABI value ≦ 0.8, it is determined that the possibility of arterial occlusion is high. In the case of ABI value ≧ 1.3, it is determined that the artery is calcified.

  The inspection apparatus can also perform a PWV (Pulse Wave Velocity) inspection for inspecting the speed (pulse wave propagation speed) at which the heart beat (pulse wave) reaches the hands and feet via the artery. The propagation speed of the pulse wave tends to increase due to arteriosclerosis, and in the case of a normal blood vessel, the speed tends to decrease due to elasticity. Therefore, it becomes possible to determine the progress of arteriosclerosis of the subject from the test result of the PWV test.

Japanese Patent No. 3140007

  However, the inspection apparatus described in the above-mentioned Patent Document 1 has a mechanism for adjusting the pressure by wrapping the cuff around the wrist and ankle of the subject to pressurize and depressurize, so the entire apparatus is large. In addition, since the test is performed with the subject's limbs restrained, there is a problem that the burden on the subject is heavy.

  Furthermore, the subject can only be examined at a hospital or the like where the examination apparatus is installed. Therefore, the conventional apparatus has a problem that ABI inspection and PWV inspection cannot be easily performed at a place other than a hospital (for example, at home).

  Therefore, in view of the above circumstances, an object of the present invention is to provide a blood flow pulse wave inspection apparatus that solves the above problems.

In order to solve the above problems, the present invention has the following means.
(1) The present invention provides a first blood flow measuring means for measuring blood flow in a wrist of a subject,
A second blood flow measuring means for measuring blood flow in the subject's ankle;
Control means for calculating a test result based on the first blood flow measurement signal measured by the first blood flow measurement means and the second blood flow measurement signal measured by the second blood flow measurement means;
Storage means for storing the calculation result of the control means,
The first and second blood flow measuring means include
An optical sensor unit having a light emitting unit for irradiating light to the measurement region and a light receiving unit for receiving the light propagated through the measurement region;
Wireless communication means for outputting, as a wireless signal, a blood flow signal corresponding to the blood flow state of the measurement region based on the signal output from the light receiving unit.
(2) The said control means of this invention calculates the value of ABI from the ratio of the said 1st blood flow measurement signal and a 2nd blood flow measurement signal.
(3) The control means of the present invention is characterized in that a value of PWV is calculated from a time difference between the first blood flow measurement signal and the second blood flow measurement signal.
(4) The present invention has third blood flow measuring means for measuring the blood flow in the neck of the subject,
The control means includes a ratio between the third blood flow measurement signal measured by the third blood flow measurement means and the first blood flow measurement signal measured by the first blood flow measurement means, and the third blood flow. A ratio between the third blood flow measurement signal measured by the measurement means and the second blood flow measurement signal measured by the second blood flow measurement means is calculated.
(5) The first to third blood flow measuring means according to the present invention include an adsorbing portion that is adsorbed to a predetermined part of a subject.
(6) The light emitting unit of the present invention has a first light having a wavelength that is not easily affected by optical characteristics due to oxygen saturation in blood, and a first light having a wavelength that is affected by optical characteristics due to oxygen saturation in blood. 2 light is emitted.
(7) The control means of the present invention compares the first transmitted light amount when the light receiving unit receives the first light and the second transmitted light amount when the second light is received. And outputting a signal corresponding to the blood flow state of the measurement region.
(8) The control means of the present invention measures the blood flow state of the measurement target region based on measurement data corresponding to the transmitted light amounts of the first and second lights output from at least the two light receiving units. It is characterized by doing.
(9) The optical sensor unit of the present invention includes:
An optical path separation member configured so that a refractive index of light traveling from the light emitting unit to the measurement target region and a refractive index of light traveling from the measurement target region to the light receiving unit are different from each other;
The light emitting unit and the light receiving unit emit and receive light through the optical path separating member.

  According to the present invention, the first and second blood flow measuring means have the light emitting unit that irradiates light to the measurement region and the light receiving unit that receives the light propagated through the measurement region, and is output from the light receiving unit. In order to output a blood flow signal corresponding to the blood flow state of the measurement region based on the signal as a wireless signal, the blood flow of the subject's wrist and ankle can be easily measured without restraining the subject's limb, The test result can be stored in the storage means, and the blood flow can be measured even when the subject is outside the hospital, so that the ABI test and the PWV test can be performed in the daily life of the test subject.

It is a figure which shows the mounting state of one Example of the blood-flow pulse wave test | inspection apparatus by this invention. It is a perspective view which shows the structure of a blood-flow measurement part. It is sectional drawing which shows the mounting state of the blood flow measurement part. 1 is a system diagram showing a configuration of a blood flow pulse wave inspection system. It is a longitudinal cross-sectional view which expands and shows the structure of an optical sensor part. It is a figure for demonstrating the principle of a blood-flow measurement method. It is a graph which shows the relationship between the wavelength of a laser beam, and the light absorption state at the time of changing the oxygen saturation of blood. It is a wave form diagram of a detection signal detected with an optical sensor unit. It is a flowchart for demonstrating the ABI control process based on the detection signal from each optical sensor unit. It is a flowchart for demonstrating the PWV control process based on the detection signal from each optical sensor unit. It is a perspective view which shows the modification of a blood-flow pulse wave test | inspection apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Configuration of blood flow pulse wave inspection device]
FIG. 1 is a diagram showing a wearing state of an embodiment of a blood flow pulse wave inspection apparatus according to the present invention. As shown in FIG. 1, the blood flow pulse wave inspection apparatus 10 includes a blood flow measurement unit 20 attached to the wrist and ankle of the subject X, and a controller 30. The blood flow measurement unit 20 includes at least a wireless communication device (wireless communication unit) 40, an optical sensor unit 50, a measurement control unit 60, and a rechargeable battery 70. The controller 30 is configured to be portable and compact, and includes at least a wireless communication device (wireless communication unit) 80, a control unit 90, a storage unit (storage unit) 100, and a rechargeable battery 110.

  The blood flow measurement unit 20 includes first blood flow measurement units (first blood flow measurement means) 20A and 20C attached to the left and right wrists of the subject X, and a second blood flow measurement unit attached to the left and right ankles of the subject X. (Second blood flow measuring means) 20B and 20D. The blood flow pulse wave inspection device 10 includes a first blood flow measurement signal measured by the first blood flow measurement units 20A and 20C, and a second blood flow measurement signal measured by the second blood flow measurement units 20B and 20D. Is stored in the storage unit 100 as measurement data. In the memory | storage part 100, the measurement data for each blood flow measurement part 20A-20D are arranged in order of the measured date and time, and are memorize | stored in time series.

  The blood flow measurement unit 20 (20A to 20D) continuously measures the blood flow in each measurement region, and continuously continues for an arbitrary predetermined time (for example, 5 minutes). It is possible to appropriately select an intermittent measurement mode in which blood flow is measured and then measurement is not performed for a predetermined time (for example, 15 minutes). Further, when the intermittent measurement mode is selected, by setting the measurement time and the non-measurement time to arbitrary times, it is possible to suppress the consumption of the rechargeable battery 70 and extend the measurable time. .

  In addition, in a present Example, although the case where the blood-flow measurement part 20 (20A-20D) is attached to both the wrists and both ankles of the test subject X is shown as an example, it is not restricted to this, For example, the left wrist or right wrist, ankle A set of blood flow measuring units 20 may be attached to the two.

  The control unit 90 of the controller 30 outputs a measurement start signal instructing the blood flow measurement unit 20 (20A to 20D) to start blood flow measurement via the wireless communication device 80 according to the set measurement mode, in advance. A measurement stop signal is output when the set measurement time is reached.

  The blood flow measurement unit 20 (20A to 20D) receives a measurement start signal from the controller 30, and starts blood flow measurement by the optical sensor unit 50. The measurement data of the measured blood flow is transmitted to the wireless communication device 40. Via the controller 30. The controller 30 stores each measurement data received by the wireless communication device 80 in the storage unit 100 in time series. Further, as shown in FIG. 3, the controller 30 compares the measurement data stored in the database 230 and executes ABI control processing and PWV control processing described later, and stores the blood flow test results in the storage unit 100. Let

Therefore, according to the blood flow pulse wave inspection apparatus 10, the blood flow of the wrist and ankle of the subject X can be easily measured without restraining the limb of the subject X, and the blood flow test result (each measurement data, And the ABI test result and the PWV test result) can be stored in the storage unit 100, and the blood flow can be measured even when the subject X is outside the hospital. PWV inspection can be performed.
[Configuration of blood flow measurement unit]
FIG. 2A is a perspective view showing a configuration of the blood flow measurement unit 20 (20A to 20D). As shown in FIG. 2A, the blood flow measurement unit 20 (20A to 20D) has a flexible substrate 120 held on a thin resin belt 170. On the flexible substrate 120, a communication antenna 130, an optical A sensor unit 50, a measurement control unit 60, and a rechargeable battery 70 are mounted. Further, in the vicinity of both end portions of the belt 170, fastening portions 172 that are fastened by adjusting the winding length according to the size of the attached portion are provided. The fastening portion 172 is configured to be fastened easily by being overlapped with the belt 170.

FIG. 2B is a cross-sectional view illustrating a mounting state of the blood flow measurement unit 20 (20A to 20D). As shown in FIG. 2B, an adsorption member 140 that holds a state in close contact with the wrist and ankle of the subject X is provided inside the belt 170. The adsorbing member 140 is formed in an annular shape by an elastic rubber so as to adsorb to the skin in the region to be inspected like a suction cup. The optical sensor unit 50 is held outside the belt 170, and is attached so that the light emitting surface and the light receiving surface of the optical sensor are close to the skin of the region to be inspected through the hollow portion of the adsorption member 140.
[Configuration of blood flow pulse wave inspection system]
FIG. 3 is a system diagram showing the configuration of the blood flow pulse wave inspection system. As shown in FIG. 3, the blood flow pulse wave inspection system 200 includes the blood flow measurement unit 20 (20 </ b> A to 20 </ b> D), a controller 30, and a measurement data display device 210. The measurement data display device 210 is installed in a medical institution such as a hospital, for example, and includes a data reader 220, a database 230, a measurement data determination control device 240, and a display device 250.

  Further, the controller 30 has a touch panel type input unit 160, and a measurement mode (continuous measurement mode or intermittent measurement mode), measurement time setting, and measurement stored in the storage unit 100 by an input operation from the input unit 160. A transfer instruction signal for transferring the data and the inspection result to the database 230 can be input. Note that the measurement data of the blood flow measurement unit 20 (20A to 20D) stored in the storage unit 100 of the controller 30 is transferred to the database 230 of the measurement data display device 210 and stored, for example, for one week. .

  The data reader 220 is connected to the output unit 150 of the controller 30 and stores ABI test results, PWV test results, and measurement data (for example, blood flow measurement units 20 (20A to 20D)) stored in the storage unit 100 of the controller 30. For 1 week).

In addition, the measurement data determination control device 240 reads each measurement data stored in the database 230 and calculation results (examination results) of ABI control processing and PWV control processing described later, and determines arteriosclerosis determined based on the inspection results. The degree of progress is determined and displayed on the display device 250. Thereby, the doctor of the medical institution can examine the condition of the subject X by looking at the measurement data and the examination result displayed on the display device 250 of the measurement data display device 210.
[Configuration of Optical Sensor Unit 50]
Here, the configuration of the optical sensor unit 50 will be described. FIG. 4 is an enlarged longitudinal sectional view showing the mounting structure of the optical sensor unit 50.

  As shown in FIG. 4, the optical sensor unit 50 includes three optical sensor units 50 </ b> A to 50 </ b> C arranged in a line inside a flexible wiring board 122 formed in a dome shape.

  When each of the optical sensor units 50A, 50B, 50C is fastened to the measurement area (wrist, ankle) of the subject X, the light emitting surface and the light receiving surface of the tip portion are close to the skin surface 300 of the subject X (or Held in contact). Each of the optical sensor units 50A, 50B, 50C has the same configuration, and the same reference numerals are given to the same portions.

  The optical sensor unit 50A includes a light emitting unit 320, a light receiving unit 330, and an optical path separating member 340. The light emitting unit 320 includes a laser diode that irradiates the skin surface 300 with laser light (emitted light) A. The light receiving unit 330 includes a light receiving element that outputs an electrical signal corresponding to the amount of transmitted light. The optical path separation member 340 is made of, for example, a holographic optical element (HOE) using a hologram, and the refractive index of the laser light A emitted from the light emitting unit 320 toward the measurement region, and the measurement region The refractive indexes of the incident lights B and C that enter the light receiving unit 330 after passing through the beam are different from each other.

  A housing 350 formed in a cylindrical shape is fitted to the outer periphery of the optical path separating member 340. The light emitting unit 320 and the light receiving unit 330 are mounted on the lower surface side of the flexible wiring board 122 on the upper surface side. A wiring pattern connected to the measurement control unit 60 is formed on the flexible wiring board 122. In the wiring pattern, connection terminals of the light emitting unit 320 and the light receiving unit 330 are arranged at positions corresponding to the respective optical sensor units 50A to 50C. It is electrically connected by soldering or the like. The flexible wiring board 122 is configured to bend according to the shape of the skin surface 300 when the tips of the optical sensor units 50A to 50C come into contact with the measurement target region.

  When performing blood flow measurement, the measurement control unit 60 causes the laser light A to be emitted from the light emitting unit 320 of the optical sensor unit 50A. At this time, the laser light emitted from the light emitting unit 320 is output at a wavelength λ (λ≈805 nm) that is not affected by the oxygen saturation.

  In addition, each of the optical sensor units 50 </ b> A to 50 </ b> C is held in a state in which the tip (end surface of the optical path separation member 340) is in contact with the measurement area of the skin surface 300. The laser beam A emitted from the light emitting unit 320 passes through the optical path separating member 340 and enters the skin surface 300 from the vertical direction. Inside (inside) the skin surface 300, the laser light A travels toward the center, and the laser light A propagates toward the periphery along the skin surface 300 with the incident position as a base point. The light propagation path 370 of the laser light A is formed in an arc shape when viewed from the side, passes through the blood vessel 380, and returns to the skin surface 300.

  Thus, the light that has passed through the light propagation path 370 reaches the light-receiving side photosensor units 50B and 50C while changing to a transmitted light amount corresponding to the amount or density of red blood cells contained in the blood flowing through the blood vessel 380. Further, since the amount of transmitted light of the laser light A gradually decreases in the process of propagating inside the brain, the light reception level of the light receiving unit 330 decreases in proportion to the distance as the laser light A moves away from the base point. Accordingly, the amount of transmitted light varies depending on the distance from the incident position of the laser beam A.

  In FIG. 4, when the optical sensor unit 50A located at the left end is a light emitting side base point, the optical sensor unit 50A itself, the right adjacent optical sensor unit 50B, and the right adjacent optical sensor unit 50C are the light receiving side. This is the base point (measurement point).

The optical path separating member 340 is formed to change the density distribution of a transparent acrylic resin, for example, so that the laser light A travels straight and guides the incident lights B and C to the light receiving unit 330. The optical path separation member 340 includes an emission side transmission region 342 that transmits the laser light A emitted from the light emitting unit 320 from the base end side (upper surface side in FIG. 4) to the distal end side (lower surface side in FIG. 4), Between the incident side transmission region 344 that transmits the light propagating from the front end side (lower surface side in FIG. 4) to the proximal side (upper surface side in FIG. 4), and between the emission side transmission region 342 and the incident side transmission region 344 And a refracting region 346 formed. The refractive region 346 transmits the laser light A, but has a property of reflecting light (incident light B and C) that has passed through the bloodstream. The refracting region 346 is formed, for example, by changing the density of acrylic resin, providing a metal thin film in this region, or dispersing metal fine particles. As a result, all the light incident from the tip of the optical path separating member 340 is collected on the light receiving unit 330.
[Principle of blood flow measurement method]
FIG. 5 is a diagram for explaining the principle of the blood flow measurement method. As shown in FIG. 5, when laser light A is irradiated to the blood in the blood vessel 380 from the outside, the laser light A that has entered the blood layer 390 is reflected and scattered light components by the normal red blood cells 392 and reflected by the attached thrombus. It travels through the blood as light of both components of the scattered light component.

  The effect that light receives in the process of passing through the blood layer changes with the state of the blood, so various amounts of blood can be obtained by continuously measuring the amount of transmitted light (or the amount of reflected light) and observing changes in the amount of light. It becomes possible to observe the change of the property of.

  When the activity of the subject X becomes active, the oxygen consumption in the body increases, so that the state of blood flow caused by the hematocrit of red blood cells carrying oxygen and the oxygen saturation of blood appears as a change in light quantity.

  Here, changes such as hematocrit (Hct: volume ratio of erythrocytes per unit volume, that is, the volume concentration of erythrocytes per unit volume, also expressed as Ht) are also factors related to changes in hemoglobin density. Yes, it affects the amount of light change. The basic principle in this embodiment is that the state of the blood flow is measured by the change in the optical path and the amount of transmitted light due to the blood flow using the laser light A in this way.

  Further, the principle configuration will be described. The optical properties of blood are determined by blood cell components (especially hemoglobin inside the cells of red blood cells). In addition, erythrocytes have a property that hemoglobin easily binds to oxygen, and thus play a role of transporting oxygen. The oxygen saturation of blood is a numerical value representing what percentage of hemoglobin in the blood is bound to oxygen. The oxygen saturation is correlated with the oxygen partial pressure (PaO2) in arterial blood and is an important index of respiratory function (gas exchange).

  It is known that when the oxygen partial pressure is high, the oxygen saturation increases, and when the oxygen saturation varies, the amount of light transmitted through the blood also varies. Therefore, when blood flow is measured, more accurate measurement is possible by removing the influence of oxygen saturation.

  Factors affecting oxygen partial pressure (PaO2) include alveolar ventilation, and also the environment such as atmospheric pressure and inhaled oxygen concentration (FiO2), ventilation / blood flow ratio, gas diffusion capacity, There is gas exchange in the alveoli, such as the short circuit rate.

  The controller 30 executes an ABI control process and a PWV control process, which will be described later, on the basis of measurement data corresponding to the transmitted light amount (light intensity) generated by the light receiving units 330 of the optical sensor units 50A to 50C, and changes the blood flow state. To detect.

  The laser beam A of the light emitting unit 320 is irradiated as pulsed light or continuous light that is intermittently emitted at a predetermined time interval (for example, 10 Hz to 1 MHz). In this case, when using pulsed light, a point reduction frequency, which is a frequency at which the pulse light is reduced, is determined according to the blood flow velocity, and continuously or at a measurement sampling frequency that is at least twice the point reduction frequency. measure. When continuous light is used, the measurement sampling frequency is determined according to the blood flow velocity and measured.

  Hemoglobin (Hb) in the blood undergoes a chemical reaction with oxygen in the lungs by breathing to become HbO2 and take in oxygen into the blood. However, the degree of oxygen in the blood depending on the state of breathing ( (Oxygen saturation) is slightly different. That is, in this embodiment, when light is irradiated to blood, a phenomenon is found in which the light absorption rate changes depending on the oxygen saturation, and this phenomenon becomes a disturbance factor in the measurement of blood flow by the laser light A. It becomes possible to remove the influence of oxygen saturation.

  FIG. 6 is a graph showing the relationship between the wavelength of laser light and the light absorption state when the oxygen saturation of blood is changed. In the body, hemoglobin contained in red blood cells is divided into oxygenated hemoglobin (HbO2: graph II (shown by a broken line)) and oxygenated hemoglobin (Hb: graph I (shown by a solid line)) combined with oxygen. In these two states, the light absorption rate with respect to light is greatly different. For example, blood containing plenty of oxygen is vivid as fresh blood. On the other hand, venous blood is darker than it is because it has released oxygen. These light absorptance states change in a wide wavelength region of light as shown in graphs I and II of FIG.

  By selecting a specific wavelength from the graphs I and II in FIG. 6, even if the oxygen saturation level of hemoglobin in erythrocytes varies greatly due to oxygen metabolism in the living body, the light absorption rate is not affected and blood It can be seen that blood flow can be measured by irradiating with light.

  Regardless of the oxygen saturation of hemoglobin in red blood cells, the light absorption rate is small in a certain wavelength region. As a result, whether or not light easily passes through the blood layer is determined by the wavelength λ. Therefore, if light in a predetermined wavelength region (for example, near λ = 800 nm to 1300 nm) is used, blood flow can be measured while suppressing the influence of oxygen saturation.

  Therefore, the wavelength region of the laser beam A uses approximately 1500 nm to 1500 nm, whereby the light absorption rate of hemoglobin (Hb) is sufficiently low in practical use and includes an isosbestic point Z in this region. Utilizing the above measurement points, it can be regarded as an isosbestic point in the calculation. That is, it is possible to make the specification not affected by the oxygen saturation.

  In other wavelength regions, for example, less than λ = 600 nm, the light absorptance increases and the S / N decreases, and at wavelengths exceeding λ = 1500 nm, the light receiving sensitivity of the light receiving unit 330 is not sufficient and is not in the blood. Disturbances such as other components affect the accuracy of measurement.

  For this reason, in this embodiment, a light emitting element composed of a wavelength tunable semiconductor laser is used as the light emitting unit 320, and the wavelength of the laser light A emitted from the light emitting unit 120 is λ1 = the equal absorption point Z in the graphs I and II. Two types are set: 805 nm (first light) and a wavelength λ2 = 680 nm (second light) having the lowest light absorptance in the graph I.

  Here, a method for detecting the red blood cell concentrations R, Rp, and Rpw based on the amount of transmitted light when the laser light A receives the light propagated through the light propagation path 370 (see FIG. 4) will be described.

The calculation formula (1) of the red blood cell concentration R when the one-point one-wavelength method performed by the conventional measurement method is used can be expressed as the following formula.
R = log10 (Iin / Iout) = f (Iin, L, Ht) (1)
In the method of the formula (1), the red blood cell concentration is the incident transmitted light amount Iin of the laser beam A emitted from the light emitting unit 320, the distance (optical path length) L between the light emitting unit 320 and the light receiving unit 330, and the hematocrit ( Ht). Therefore, when the red blood cell concentration is determined by the method of formula (1), the red blood cell concentration varies depending on three factors, and it is difficult to accurately measure the red blood cell concentration.

The calculation formula (2) of the red blood cell concentration Rp when the two-point one-wavelength method according to the present embodiment is used can be expressed as the following formula.
Rp = log10 {Iout / (Iout−ΔIout)} = Φ (ΔL, Ht) (2)
In the method of formula (2), since the light is received at two points (light receiving units 130 of the optical sensor units 50B and 50C) at different distances from the laser light A as shown in FIG. This is a function of the distance ΔL and the above-described hematocrit (Ht). Therefore, when the red blood cell concentration is obtained by the method of equation (2), since the distance ΔL between the light receiving parts 330 is known in advance among the two factors, the red blood cell concentration is measured as a value using the hematocrit (Ht) as a coefficient. . Therefore, in this calculation method, the red blood cell concentration can be accurately measured as a measurement value corresponding to hematocrit (Ht).

Furthermore, the calculation formula (3) of the red blood cell concentration Rpw when the two-point two-wavelength method according to the modification of the present embodiment is used can be expressed as the following formula.
Rpw
= [Log10 {Iout / (Iout−ΔIout)} λ1] / [log10 {Iout / (Iout−ΔIout)} λ2]
= Ξ (Ht) (3)
In the method of the expression (3), the red blood cell concentration is changed by setting the wavelengths of the laser light A emitted from the light emitting unit 320 to different λ1 and λ2 (in this embodiment, λ1 = 805 nm and λ2 = 680 nm). It is measured as a function of only hematocrit (Ht). Therefore, according to this calculation method, it is possible to accurately measure the red blood cell concentration as a measurement value according to hematocrit (Ht).

  The propagation of the light is adjacent to the light-emitting side optical sensor unit 50A with a predetermined distance because the light propagation path becomes longer and the light transmittance decreases as the distance from the base point irradiated with the laser light A increases in the radial direction. The received light level (transmitted light amount) of the optical sensor unit 50B is strong, and then the received light level (transmitted light amount) of the optical sensor unit 50C provided adjacent to it by a predetermined distance is weaker than the received light level of the optical sensor unit 50B. Detected. The light receiving unit 330 of the light-emitting side optical sensor unit 50A also receives light from the skin surface 300. In the controller 30, detection signals corresponding to the light intensities received by the plurality of optical sensor units 50 </ b> A to 50 </ b> C are stored in the storage unit 100 in time series.

  Further, the red blood cell concentration is hematocrit (Ht) by setting the detection signal (signal corresponding to the amount of transmitted light received) output from each of the optical sensor units 50A to 50C as Iout in the above-described equation (2) or (3). It becomes possible to measure accurately as a measurement value according to (a value not affected by oxygen saturation).

  FIG. 7 is a waveform diagram showing waveforms of detection signals of the respective optical sensor units 50A to 50C. As shown in FIG. 7, by comparing the light receiving portion detection signal waveforms (A) to (C) with the emission time Ts of the laser light A emitted from the light emitting portion 320 as a base point, the emission time Ts and the light receiving portion detection are compared. Phase differences T1 to T3 from the lowest values of signals (A) to (C) are obtained.

  The phase differences T1 to T3 have a relationship of T1 <T2 <T3 and change according to the pulse wave propagation velocity. The approximate values Δt1 and Δt2 of PWV are obtained from the phase differences of the detection signals of the optical sensor units 50A to 50C, T2−T1 = Δt1, and T3−T1 = Δt2.

Further, the maximum outputs X1 to X3 of the detection signals of the respective optical sensor units 50A to 50C have a relationship of X1>X2> X3, and change according to the light intensity when propagating through the body (in blood). Changes according to the increase or decrease of blood flow in the propagation path. An approximate value of ABI is obtained by calculating the output ratios X1 / X2 and X1 / X3 of the detection signal waveforms of the respective optical sensor units 50A to 50C.
[Control processing by measurement data determination control device 240]
Here, ABI control processing and PWV control processing executed by the measurement data determination control device 240 based on the above principle will be described.

  FIG. 8 is a flowchart for explaining ABI control processing based on detection signals from the respective optical sensor units. As shown in FIG. 8, the measurement data determination control device 240 reads each measurement data (measurement data based on the amount of transmitted light corresponding to the blood flow) stored in the database 230 in S11. Subsequently, the process proceeds to S12, and the red blood cell concentration Rp or Rpw is calculated using each measurement data and the arithmetic expression (2) or (3) described above.

  In the next S13, a change in the displacement state of the blood vessel and the tissue around the blood vessel due to the blood flow is obtained from the change in the red blood cell concentration at each measurement position, and based on the displacement state of the blood vessel and the tissue around the blood vessel, Deriving blood flow velocity.

  Then, it progresses to S14 and the detection signal waveform (or waveform of the inner wall displacement data corresponding to a blood flow change) output from each photosensor unit 50A-50C is compared.

  In the next S15, as shown in FIG. 7, the output ratios X1 / X2 and X1 / X3 of the waveforms of the detection signals (A) to (C) are calculated to obtain an approximate value of ABI.

  Subsequently, in S16, the degree of arteriosclerosis based on the approximate value of ABI is stored in the database 230, and the measurement result of the blood vessel characteristic corresponding to the degree of arteriosclerosis based on the approximate value of ABI and the approximate value of ABI obtained this time is displayed. It is displayed on the display device 250. In addition, when four blood flow measurement units 20 (20A to 20D) are attached to both wrists and both ankles of the subject X, the measurement data is compared between the left side and the right side, and the compared average value is calculated. Remember as a result.

  Subsequently, the process proceeds to S17, where it is checked whether the calculation of ABI and the detection of blood vessel characteristics have been completed for all measurement data (for example, all data for one week) of each of the optical sensor units 50A to 50C. In S17, when the calculation of ABI for all measurement data and the detection of the blood vessel characteristics are not completed, the process returns to S11 and the processes after S11 are repeated.

  In S17, when the calculation of ABI for all measurement data and the detection of blood vessel characteristics are completed, the process proceeds to S18, and the ABI measurement results of all measurement data input from the controller 30 and the blood vessel characteristics are displayed on the monitor 290. indicate. Thereby, the subject X can confirm the ABI measurement result and the blood vessel characteristic based on all the measurement data measured in the life of a predetermined period (for example, one week).

  FIG. 9 is a flowchart for explaining PWV control processing based on detection signals from the respective optical sensor units. In FIG. 9, the processes of S21 to S24 are the same as the processes of S11 to S14 described above, and thus the description thereof is omitted.

  In S25, as shown in FIG. 7, the PWV values Δt1 and Δt2 are calculated based on the phase difference of the detection signal waveforms of the detection signals (A) to (C), T2−T1 = Δt1, and T3−T1 = Δt2. . Furthermore, the pulse wave propagation speed based on the value of PWV is calculated, and the blood vessel characteristics (the elasticity ratio of the blood vessel, the plaque amount in the blood vessel, the arteriosclerosis ratio) corresponding to the pulse wave propagation speed are calculated in the database 230. The degree of arteriosclerosis of the blood vessel in the measurement area is derived. Subsequently, in S26, the pulse wave propagation speed based on the value of PWV and the arteriosclerosis degree of the blood vessel are stored in the database 230, and the pulse wave propagation speed based on the value of PWV and the arteriosclerosis degree of the blood vessel are displayed on the display device 250. To do. When four blood flow measurement units 20 (20A to 20D) are attached to both wrists and both ankles of the subject X, the phase difference of the measurement data is obtained between the left side and the right side, and the left and right sides are measured. The average value of the phase difference is stored as the calculation result.

  Then, it progresses to S27 and it is checked whether the calculation of PWV about all the measurement data (for example, all the data for one week) of each optical sensor unit 50A-50C, and the detection of the pulse wave velocity were completed. . In S27, when the calculation of PWV and the detection of the pulse wave velocity are not completed for all measurement data, the process returns to S21 and the processes after S21 are repeated.

In S27, when the calculation of PWV for all measurement data and the detection of the pulse wave velocity are completed, the process proceeds to S28, and the PWV measurement result of all measurement data input from the controller 30 and the pulse wave velocity. Is displayed on the monitor 290. Thereby, the subject X can check the PWV measurement result and the pulse wave propagation speed based on all measurement data measured in the life of a predetermined period (for example, one week).
[Modification]
FIG. 10 is a perspective view showing a modification of the blood flow pulse wave inspection apparatus. As shown in FIG. 10, in the blood flow pulse wave inspection device 400 according to the modification, the blood flow measurement unit 20 (20 </ b> A to 20 </ b> D) is attached to a chair 410 on which the subject X sits. Blood flow measuring units 20A and 20C that measure the blood flow of the wrist of the subject X are provided on the armrests 412 and 414. In addition, blood flow measuring units 20B and 20D that measure blood flow in the ankle of the subject X are provided in the footrest recesses 416 and 418, respectively.

  Further, a rotating arm 450 that can be rotated in the horizontal direction is supported on the left side surface of the backrest upper portion 420 of the chair 410, and a third blood flow measuring unit (third blood flow) is provided at the tip of the rotating arm 450. Flow measurement means) 20E is provided. The blood flow measurement unit 20E is movably attached so as to measure the blood flow of the neck of the subject X from the front. The blood flow measurement unit 20E is stably supported so that the weight of the rotating arm 450 and the blood flow measurement unit 20E does not act on the neck so as not to press the neck of the subject X.

  The blood flow measurement unit 20E can measure the blood flow in the carotid artery of the neck that is relatively close to the heart. Therefore, the ABI test and the PWV test can also be performed by comparing the measurement data of the blood flow measured by the blood flow measurement unit 20E with the measurement data of the blood flow measurement units 20A to 20D attached to the wrist and ankle. It becomes possible.

  That is, the measurement data determination control device 240 compares the ratio between the third blood flow measurement signal measured by the third blood flow measurement unit 20E and the first blood flow measurement signal measured by the first blood flow measurement units 20A and 20C. And the value of ABI by calculating the ratio between the third blood flow measurement signal measured by the third blood flow measurement unit and the second blood flow measurement signal measured by the second blood flow measurement units 20B and 20D. Can be calculated. In addition, the measurement data determination control device 240 has a time difference between the third blood flow measurement signal measured by the third blood flow measurement unit 20E and the first blood flow measurement signals measured by the first blood flow measurement units 20A and 20C. And the value of PWV by calculating the time between the third blood flow measurement signal measured by the third blood flow measurement unit and the second blood flow measurement signals measured by the second blood flow measurement units 20B and 20D. Can be calculated.

  A controller 30 </ b> A is installed on the right side surface of the chair 410. Further, the armrest 414 on the left side of the chair 410 is provided with an input unit 160A made of a touch panel type liquid crystal panel. The subject X can input each setting condition by operating the input unit 160 while sitting on the chair 410 and confirms the measurement data from the blood flow measurement units 20A to 20E on the display of the liquid crystal panel. You can also.

  The controller 30A includes a memory card reader / writer 440 into which a memory card (storage means) 430 that stores measurement data from the blood flow measurement units 20A to 20E is inserted. The subject X takes out the memory card 430 from the memory card reader / writer 440 and takes it to the medical institution. Then, the operator of the medical institution reads the measurement data and test results stored in the memory card 430 into the measurement data display device 210 of the medical institution, and transfers the measurement data of the memory card 430 to the database 230.

  Thereby, the doctor of the medical institution can examine the condition of the subject X by looking at the measurement data and the examination result displayed on the display device 250 of the measurement data display device 210.

  As a method of transferring the measurement data stored in the memory card 430, a method of inserting the memory card 430 into a card reader / writer of a personal computer and transmitting it to the measurement data display device 210 of the medical institution via the Internet may be used. .

  The subject X installs the blood flow pulse wave inspection device 400 at home, for example, so that each blood flow measurement unit 20A to 20E measures blood flow every time he sits on a chair 410 at home, and each blood flow measurement unit 20A Measurement data output from ˜20E is stored in the memory card 430. Therefore, the subject X can record blood flow measurement data at home without going to a medical institution.

  Therefore, according to the blood flow pulse wave inspection apparatus 400, the blood flow of the wrist and ankle of the subject X is easily measured without restraining the limb of the subject X, and the test result of the subject X is stored in the storage unit 100. Since the blood flow can be measured even when the subject X is outside the hospital, the ABI test and the PWV test in the daily life of the test subject X can be performed.

  In the above-described embodiment, the configuration in which the optical sensor unit 50 includes the three optical sensor units 50A to 50C is illustrated. However, the configuration is not limited thereto, and at least the light emitting unit and the two light receiving units are separated from each other by a predetermined distance. It may be of a different configuration.

10, 400 Blood flow pulse wave inspection device 20 (20A to 20D), 20E Blood flow measurement unit 30, 30A Controller 40, 80 Wireless communication device 50 Optical sensor unit 60 Measurement control unit 70, 110 Rechargeable battery 90 Control unit 100 Storage Unit 120 flexible substrate 122 flexible wiring board 130 communication antenna 140 adsorption member 150 output unit 160 input unit 170 belt 200 blood flow pulse wave inspection system 210 measurement data display device 220 data reader 230 database 240 measurement data determination control device 250 display device 300 Skin surface 320 Light emitting unit 330 Light receiving unit 340 Optical path separating member 342 Outgoing side transmission region 344 Incident side transmission region 346 Refraction region 350 Housing 370 Light propagation path 380 Blood vessel 410 Chair 412, 414 Armrest 416, 418 Footrest Recess 430 Memory card 440 The memory card reader / writer 450 pivot arm

Claims (9)

First blood flow measuring means for measuring blood flow in the wrist of the subject;
A second blood flow measuring means for measuring blood flow in the subject's ankle;
Control means for calculating a test result based on the first blood flow measurement signal measured by the first blood flow measurement means and the second blood flow measurement signal measured by the second blood flow measurement means;
Storage means for storing the calculation result of the control means,
The first and second blood flow measuring means include
An optical sensor unit having a light emitting unit for irradiating light to the measurement region and a light receiving unit for receiving the light propagated through the measurement region;
A blood flow pulse wave inspection apparatus comprising: a wireless communication unit that outputs a blood flow signal corresponding to a blood flow state of a measurement target region as a wireless signal based on a signal output from the light receiving unit.   The blood flow pulse wave inspection apparatus according to claim 1, wherein the control means calculates an ABI value from a ratio between the first blood flow measurement signal and the second blood flow measurement signal.   The blood flow pulse wave inspection apparatus according to claim 1, wherein the control unit calculates a value of PWV from a time difference between the first blood flow measurement signal and the second blood flow measurement signal. Having a third blood flow measuring means for measuring the blood flow in the neck of the subject;
The control means includes a ratio between the third blood flow measurement signal measured by the third blood flow measurement means and the first blood flow measurement signal measured by the first blood flow measurement means, and the third blood flow. 4. The ratio of the third blood flow measurement signal measured by the measurement means and the second blood flow measurement signal measured by the second blood flow measurement means is calculated. The blood flow pulse wave inspection apparatus according to 1.   The blood flow pulse wave inspection apparatus according to any one of claims 1 to 4, wherein the first to third blood flow measurement means include an adsorption portion that is adsorbed to a predetermined part of a subject.   The light emitting unit emits first light having a wavelength that is not easily influenced by optical characteristics due to oxygen saturation in blood, and second light having a wavelength that is affected by optical characteristics due to oxygen saturation in blood. The blood flow pulse wave inspection device according to any one of claims 1 to 5, wherein   The control means compares the first transmitted light amount when the light receiving unit receives the first light and the second transmitted light amount when the second light is received, and thereby the measurement target region The blood flow pulse wave inspection apparatus according to claim 1, wherein a signal corresponding to a blood flow state is output.   The control means measures a blood flow state in the measurement region based on measurement data corresponding to transmitted light amounts of the first and second lights output from at least the two light receiving units. The blood flow pulse wave inspection device according to any one of claims 1 to 7. The optical sensor unit is
An optical path separation member configured so that a refractive index of light traveling from the light emitting unit to the measurement target region and a refractive index of light traveling from the measurement target region to the light receiving unit are different from each other;
The blood flow pulse wave inspection apparatus according to claim 1, wherein the light emitting unit and the light receiving unit emit and receive light through the optical path separating member.

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