JP6692347B2 - Methods for assessing blood fluidity - Google Patents

Description

This application is based on Japanese Patent Application No. 2015-71055 filed in Japan, the contents of which are incorporated herein by reference.
TECHNICAL FIELD The present invention relates to a method and a device capable of easily evaluating blood fluidity from the outside.

  Recently, there is a strong demand to help maintain health by objectively knowing the fluidity of blood. However, in order to know the fluidity of blood, it is generally necessary to collect blood and examine it, which is not easy to carry out.

  Heretofore, attempts have been made to evaluate the function of the heart, blood pressure, arteriosclerosis, etc. by objectively measuring the peripheral circulation state of the living body, but not for knowing the fluidity of blood. The device of this type described in Patent Document 1 is a pressing device that presses a predetermined region of a living body to cause ischemia, and a return of blood to the predetermined region of the living body when the pressing of the pressing device is released. A blood return amount detection device that optically detects the amount, and a blood return amount display means that graphically displays a change in the return amount of blood detected by the blood return amount detection device along a predetermined time axis along with time, In order to evaluate the function, the blood flow returns when returning from the ischemic state.

JP, 11-89808, A

  When measuring the blood flow change when the compression is released as in the technique described in Patent Document 1, all the vascular systems are simultaneously filled with blood when the compression is released. Even if the element spacing is optimized, it is difficult to completely distinguish the arterial system from the capillary system. Further, the pressure of blood sent from the heart, which is so-called blood pressure, affects the blood pressure and the calibration is difficult. Furthermore, since blood pressure pulsates according to the heartbeat, it is necessary to remove the pulsating component, but it is difficult to remove it. Therefore, even though blood flow data of only the capillary system is required for blood fluidity evaluation, extraneous information such as arteries is included in the measured data. It was impossible to evaluate the sex.

  The present invention provides a method and apparatus capable of easily and sensitively evaluating the fluidity of blood in consideration of the above circumstances and capable of clearly detecting aspects of a subject having various blood vessel states and blood flow states. With the goal.

As a result of intensive studies by the present inventors, the present invention as described below was completed.
(1) The pressing member is pressed against the test site of the subject with the pressure of the primary pressure, the blood in the test site is caused to flow out to the periphery of the test site, and then the pressure of pressing the pressing member is reduced to the secondary pressure. Then, the pressure for pressing the pressing member is released, and then the pressing pressure for pressing the pressing member is increased to the primary pressure. A method for evaluating blood fluidity, comprising the step of measuring changes using light scattering, wherein the secondary pressure value has at least two different values over a plurality of pressing cycles.
(2) The method according to (1), wherein the time required for one pressing cycle is 5 to 15 seconds.
(3) The secondary pressure has 4 to 10 different values including the maximum secondary pressure and the minimum secondary pressure, and with the execution of the pressing cycle, the maximum secondary pressure to the minimum secondary pressure is increased. The secondary pressure is applied to the secondary pressure in order of decreasing pressure, and the maximum secondary pressure is applied in the pressing cycle next to the pressing cycle in which the minimum secondary pressure is applied, (1) or ( Method 2).
(4) Further, the method according to any one of (1) to (3), in which the pulse of the subject is measured, and the drive of the pressing member is controlled based on the acquired measurement data of the pulse.
(5) The time for pressing the primary pressure is 1 to 3 beats based on the measurement data of the pulse, and the time for pressing secondary pressure is 1 to 5 beats based on the measurement data of the pulse. The method of (4) which controls the drive of the pressing member so as to be the same.
(6) A pressing member that can be pressed against the test site by the subject, a drive control device that controls and drives the pressing member, and a light-emitting element that is incorporated into the pressing member and irradiates the test site with light. A light-receiving element that is incorporated in the pressing member to detect light scattered in the test site, a calculation unit that calculates the blood volume and blood fluidity of the test site from the measurement data of the light-receiving element, and the blood volume and blood fluidity Display means for displaying at least one of them, and the drive control device is configured so that the pressure for pressing the pressing member can be set to the primary pressure and two or more different secondary pressures lower than the primary pressure. Blood fluidity evaluation device.
(7) A pulse measuring unit for measuring the pulse of the subject at a pulse measuring region different from the test region of the subject is further provided, and the drive control device controls the drive of the pressing member based on the measurement data of the pulse measuring unit. The device of (6) that is configured.

  According to the present invention, there is provided a method and device capable of easily evaluating blood fluidity. According to the present invention, since it is sufficient that the light emitting element and the light receiving element are incorporated in the pressing member, it is possible to reduce the size of the pressing member. Further, by applying two or more different secondary pressures, it is possible to more clearly capture changes in the blood flow state due to various pathological conditions.

1 is a block diagram showing a schematic configuration of one embodiment of a blood fluidity evaluation device according to the present invention. It is an example of a pressure profile in the evaluation method of the present invention. It is a schematic diagram of the measurement by the apparatus of another aspect of the present invention. It is an external view of the apparatus used in the Example of this invention. The result of the blood fluidity evaluation example of a healthy person regarding a certain scleroderma is shown. The results of four blood fluidity evaluation examples are shown.

  Hereinafter, the present invention will be described in detail with reference to the drawings. However, the invention is not limited to the illustrated embodiment.

FIG. 1 is a block diagram showing a schematic configuration of one embodiment of the blood fluidity evaluation device according to the present invention.
This blood fluidity evaluation device has a pressing member that is pressed against a test site such as the fingertip of the test subject. The pressing member is pressed against the test site of the subject or released by the control of the drive control device including the pressurizing mechanism and the pressing force sequence control unit. A light emitting element (light source) and a light receiving element (photodetector) are incorporated in the pressing member. The light emitting element is an element that emits light for irradiating the pressed test site. The light emitted from the light emitting element is scattered within the test site and detected by the light receiving element. As described later, the blood volume at the test site can be calculated from the comparison between the light emission from the light emitting element and the measurement data from the light receiving element. Then, the blood fluidity at the test site can be evaluated from the data such as the degree and time of pressing by the pressing member and the change with time of the blood volume. This blood fluidity evaluation device is also provided with a computing unit (a hemoglobin concentration estimation unit or the like) for calculating the blood volume and blood fluidity in this way, and a display unit for displaying at least one of them.

  The pressing member itself is configured to be pressed against a test site such as the skin by moving back and forth on one axis, for example. The movement of the pressing member is controlled by electrically controlling the actuator by a pressure mechanism, a pressure sequence control unit (drive control device), or the like.

  In order to press the pressing member against a predetermined position of the test site, it is preferable to prepare a predetermined measuring table or the like on which the test site (finger etc.) is placed. At that time, in order to minimize the influence on the blood flow, it is preferable that the measurement table is configured not to apply pressure to the test site. More accurate positioning of the pressing member to the test site will be described later.

  The light emitting element is incorporated in the pressing member. The light emitting element is driven and controlled by the light emitting element driving circuit, and the signal of the light receiving element is input to the hemoglobin concentration estimating unit after being amplified by the amplifying circuit or the like (preamplifier or the like) as necessary through the light receiving signal detection circuit. .. The number of light emitting elements and the number of light receiving elements are not particularly limited. For example, a plurality of light receiving elements may be provided, and a plurality of light receiving signals from the respective light receiving elements may be averaged to be used for evaluation calculation of blood fluidity. In this way, the influence of the error due to the measurement position and the like can be mitigated. The light emitting element emits light toward the surface of the test site such as the skin of a finger, and the light receiving element is configured to receive the return light from the test site.

  The light emitting element is preferably made of a material that emits light of blue or a short wavelength close thereto, and the light receiving element is made of a material that can receive the above-mentioned light.

  The hemoglobin concentration estimation unit calculates the blood volume from the measurement data of the light receiving element. The hemoglobin concentration estimation unit also calculates blood fluidity. The blood fluidity is obtained from the change over time in blood volume after the pressing member starts pressing against the test site. The control PC drives and controls all of the light emitting element drive circuit (power amplifier and the like), the received light signal amplification circuit (preamplifier and the like), and the display section.

  According to the present invention, the drive control device is configured so that the pressure with which the pressing member is pressed can be set to the primary pressure and the secondary pressure. Here, the secondary pressure has two or more different pressures. The primary pressure is higher than any secondary pressure.

  FIG. 2 is an example of a pressure profile in the evaluation method of the present invention. In the profile shown, the primary pressure is 304 mmHg. The secondary pressure has six values of 109 mmHg, 88 mmHg, 64 mmHg, 53 mmHg, 40 mmHg and 28 mmHg. The secondary pressure preferably has 4 to 10 different values.

  As shown in the figure, first, the pressing member is pressed with the pressure of the primary pressure. As a result, the blood in the test site is allowed to flow out around the test site. Next, the pressure with which the pressing member is pressed is reduced to the secondary pressure. Further, the pressure applied to the pressing member is released. Then, the pressure with which the pressing member is pressed is increased to the primary pressure. The series of pressure changes up to this point is regarded as one pressing cycle. In the profile shown, one pressing cycle takes 10 seconds. Preferably, the time required for one pressing cycle is 5 to 15 seconds. It is particularly preferable that the time for which one pressing cycle is performed be determined in combination with the pulse measurement described later. For example, the time for pressing the primary pressure is set to 1 to 3 beats based on the pulse measurement data, and the time for pressing the secondary pressure is set to 1 to 5 beats based on the pulse measurement data. There are things to do.

  In the present invention, as described above, the pressing cycle in the order of the primary pressure, then the secondary pressure, then the pressure release, and then the primary pressure is repeated, and the secondary pressure has at least two different pressure values. All you have to do is do it.

  Thus, by repeating the pressing cycle as described above with the secondary pressure having at least two different pressure values, there are the following advantages in the blood fluidity evaluation. Since there are individual differences in the intravascular pressure of the peripheral blood vessels, by applying two or more different secondary pressures, the common measurement procedure can be applied even when the intravascular pressure of the subject is unknown. Further, when the secondary pressure is applied, a pressure (ambient pressure) that is in equilibrium with the secondary pressure is applied around the blood vessel, so that blood is refilled in the peripheral vascular system up to the volume where the ambient pressure and the intravascular pressure are equilibrated. This is to measure the response of the peripheral vascular system when a load of ambient pressure is applied to the blood vessel, and the superiority or inferiority of the blood refilling capacity of the peripheral vascular system to the pressure load can be measured.

  Preferably, the secondary pressure has 4 to 10 different values including the maximum secondary pressure and the minimum secondary pressure, and the maximum secondary pressure to the minimum secondary pressure is increased as the pressing cycle is performed. The secondary pressure is applied to the pressure in the order of decreasing pressure, and the maximum secondary pressure is applied in the pressing cycle following the pressing cycle in which the minimum secondary pressure is applied. In the profile of FIG. 2, the maximum secondary pressure is 109 mmHg and the minimum secondary pressure is 28 mmHg. Then, first the primary pressure (304 mmHg) is applied, then the maximum secondary pressure (109 mmHg), then the pressure release, then the primary pressure (304 mmHg), which is the first pressing cycle. Subsequently, the next pressing cycle is applied, the primary pressure (304 mmHg) is applied, then the second largest secondary pressure (88 mmHg), then the pressure release, then the primary pressure (304 mmHg). Thereafter, the pressing cycle is repeated, and at that time, the secondary pressure is applied so as to be gradually reduced. In the sixth pressing cycle, the primary pressure (304 mmHg) is applied, then the minimum secondary pressure (28 mmHg), then the pressure release, then the primary pressure (304 mmHg). In the seventh pressing cycle, the primary pressure (304 mmHg) is applied, then the maximum secondary pressure (109 mmHg), then the pressure release, and then the primary pressure (304 mmHg). In this way, the pressing cycle is repeated.

  As described above, by gradually lowering the pressure value of the secondary pressure as the pressing cycle is repeated, the above-described effect in the blood fluidity evaluation can be further effectively demonstrated.

  In the evaluation device of the present invention, the drive control device is configured to realize the pressing cycle as described above. Specifically, the pressing cycle time and pressure value may be stored in the control PC in FIG. 1, and the pressurizing mechanism may be controlled via the pressurizing sequence controller and the power amplifier.

Next, the combined use with the pulse measuring means will be described.
FIG. 3 is a schematic diagram of measurement by the apparatus according to another aspect of the present invention. In the illustrated embodiment, there is a unit 10 for evaluating blood fluidity with the tip of the index finger as the test site 100 and a unit 11 for measuring the pulse of the ring finger. In this case, the index finger is evaluated as the test site 100, and the ring finger is evaluated as the pulse measurement site 110. The unit 10 includes the pressing member, the light emitting element, and the light receiving element described above. The unit 10 and the unit 11 can be operated in conjunction with each other as described later via the above. The device of FIG. 3 is configured to actuate the two units 10, 11 on different fingers of one hand, but the device of the present invention is not limited to such a configuration.

  The specific configuration of the pulse measuring means is not particularly limited. As an example, a unit similar to the unit including the pressing member, the light emitting element (light source) and the light receiving element (photodetector) described above can be mentioned. The mode of measuring the pulse with this unit is as follows. A pulse wave can be detected by irradiating light while pressing the pulse measurement site 110 with a weak force and detecting the scattered light. The pressing pressure when detecting the pulse wave is a weak pressure at which the blood at the pressed portion does not easily flow out to the surroundings, and specifically, it is preferably about 30 to 60 mmHg. The pulse measuring means utilizing such pulse wave detection can be used in the present invention.

  As described above, since light can be used for detecting the pulse wave as in the case of detecting the blood volume, an error due to the pulse wave may occur when detecting the blood volume in the unit 10. For example, the start of pressing by the pressing member may cause an error because the amount of blood in the tissue is strictly different depending on whether the blood of the test site 100 is immediately inflowing or just before inflowing into the tissue of the test site 100. .. In order to eliminate or reduce this error, in the preferred embodiment of the present invention, it is proposed that the measurement data of the pulse at the pulse measurement site 110 be used to reduce the calculation error due to the pulse when calculating the blood fluidity. To be done.

  Further, preferably, the measurement data of the pulse at the pulse measurement site 110 is used to control the drive of the pressing site in the unit 10 for evaluating the blood fluidity. For example, a method of observing the pulse wave in the unit 11 for measuring the pulse and starting the pressing at the time when the inflow of the blood into the test site 100 becomes maximum or minimum can be mentioned. In this case, the pulse may be measured in a unit 11 different from the unit 10 for blood fluidity evaluation as shown in FIG. 3, or in the same unit as the blood fluidity evaluation, the pulse may be measured first and then predetermined. At times, the measurement may be switched to blood fluidity measurement. From the viewpoint that no force is applied to the test site 100 before the blood fluidity evaluation, it is preferable to provide a unit 11 different from the unit 10 for blood fluidity evaluation to measure the pulse.

  Further, preferably, the time of one pressing cycle described above may be set using the measurement data of the pulse. For example, the time of one pressing cycle is such that the time for pressing the primary pressure is a pulse length of 1 to 3 beats, and the time for pressing the secondary pressure is a pulse length of 1 to 5 beats. Is mentioned. At this time, the pulse rate may be used as a reference for the time for releasing the pressure applied by the pressing member, or may be set as 3 to 5 seconds.

Next, a measure for improving the positioning accuracy of the test site using the pulse measurement will be described.
Prior to the measurement of blood fluidity, in the unit 10 for evaluating blood fluidity, the pressing member is pressed against the test site 100 with the weak force described above, and pulse measurement data is acquired by light absorption. At this time, the pulse wave component that detects that the positional relationship between the pressing member and the test site 100 is inappropriate becomes weak. Therefore, it can be said that the pulse measurement data is measured while moving the relative position between the pressing member and the test site 100, and the relative position at which the measurement data becomes maximum is a preferable position for blood fluidity evaluation. When the human finger is used as the test site, usually, a preferable measurement position can be determined by obtaining a position where the measurement data of the pulse becomes maximum in a 5 mm square near the fingertip.

Next, the principle of blood fluidity measurement will be described.
There are capillaries at a shallow position under the skin, and arteries and veins at a deep position. When pressure is applied to the skin, the flow path diameter of arteries and veins is large, so blood rapidly flows out to other parts, but capillary blood vessels have a small flow path diameter and large flow path resistance, so blood flow slowly. Spills into the surrounding area. Further, when the capillaries are compressed, the blood flow channel is further narrowed, and the outflow rate is further reduced due to the influence of the change in fluidity such as the aggregation of red blood cells and the lowering of deformability.

  The time change (speed) of this blood outflow depends on the blood flow resistance (one of which is the viscosity of blood). Therefore, in this embodiment, the blood fluidity is estimated by optically detecting the time change of blood outflow from the capillaries.

  In general, visible light has a large absorption of hemoglobin and other living body constituents in a living body, and almost cannot be transmitted. However, when pressure is applied to the skin and blood flows out from the capillaries, blood (hemoglobin) is reduced accordingly, and light absorption in the living body is reduced as compared with that before the pressure is applied. That is, the pressure causes the blood in the capillaries to flow out, and the light is transmitted as the blood volume (hemoglobin amount) decreases.

  In addition, light with a short wavelength hardly penetrates through the living body. That is, it is considered that observing the short-wavelength light applied to the living body is observing the light that has propagated through the capillaries just below the skin. By utilizing this principle, the state of blood outflow in the capillaries due to the application of pressure can be observed, and from this, the change in hemoglobin concentration in the tissue can be estimated.

  In this case, it is desirable that the light emitting element and the light receiving element are set so as to detect only the blood volume of the capillaries under the skin and not the blood volume of the arteries and arterioles. Therefore, it is preferable to bring the light emitting element and the light receiving element closer to each other so that the blood flow in the shallow portion can be detected with high sensitivity. The wavelength of light to be irradiated may be red or infrared, but is preferably blue or a short wavelength close to blue.

  This is because the longer the wavelength of light, the less scattering in the middle, and the light penetrates deep (to reach the artery), but the shorter the wavelength of light, the deeper it does not reach (to reach the artery). , Because it will come back in a shallow position. In other words, the light emitted from the light emitting element enters the skin and repeatedly scatters inside, and part of it returns to the skin surface, but since there is a blood vessel in the path of that light, the return light is Be absorbed by blood. Therefore, by using short-wavelength light, the absorption of light by blood in capillaries in the shallow part is not affected by the absorption of light by arterioles and blood in the deep part under the skin. The effect is that the light returns to the skin surface.

  For example, when a blue LED is used as a light emitting element, a phototransistor is arranged as a light receiving element preferably at a distance within about 3 mm from the blue LED.

Next, the measuring method will be described.
At the time of measurement, the pressing member is brought close to the vicinity of the test site 100 such as the fingertip. It is preferable to use a measuring table (not shown) or the like that is shaped so that the test site 100 can be fixed. When the operation switch is operated, the pressing device and the pressurization sequence control unit are operated, and the pressing member moves so as to press against the test site 100, and the primary pressure, the secondary pressure, and the pressure release as described above are pressed. The cycle repeats.

  Then, while repeating the above-mentioned pressing cycle, optical measurement is performed by the light emitting element (light source) and the light receiving element (photodetector) incorporated in the pressing member. Then, the signal from the light receiving element with respect to the passage of time is amplified and input to the hemoglobin concentration estimation unit, where the property of blood flowing in the capillaries (blood Data indicating the flow resistance) is calculated. This data includes an index indicating blood fluidity and blood viscosity in the capillaries and is displayed by the display unit.

  For example, in principle, the larger the blood volume, the greater the light absorption and the smaller the received light volume. The opposite is true when blood volume is low. Therefore, considering further, the fact that the amount of received light is large means that the amount of light absorbed is small, the amount of blood is small, and blood easily escapes by pressing, that is, the viscosity is low, and the small amount of received light means that Means the opposite. Further, in the present invention, when at least two different secondary pressures are applied, examining changes in blood volume due to the difference in secondary pressure also leads to obtaining basic data for inferring various pathological conditions.

  In the present invention, the blood flow resistance is evaluated based on the time change of blood outflow from the capillaries when the surface of the test site 100 is pressed. The fluidity of blood (for example, the viscosity of blood) can be evaluated with high sensitivity without being affected by the blood flow of arteries and veins located deeper than capillaries. In other words, arteries and veins originally have lower vascular resistance than capillaries, and when they are pressed, blood flows out rapidly, so it is possible to measure only the outflow of blood that remains in the capillary system without being affected by them. Is. Then, the fluidity of blood can be accurately evaluated based on the measurement. In particular, the measurement structure can be simplified by externally optically measuring the change in the amount of blood remaining under the skin by utilizing the absorption of light by hemoglobin.

  Examples according to the present invention will be shown below, but the present invention is not limited to these examples.

  Blood fluidity was evaluated according to the measurement profile shown in FIG. 2 except that the primary pressure was changed from 304 mmHg to 309 mmHg. The measurement was performed by manufacturing the evaluation device shown in FIG. The apparatus includes a measurement sensor 21 and a beat synchronization optical sensor 22. As described above, the primary pressure was 309 mmHg, and the secondary pressure was 109 mmHg, 88 mmHg, 64 mmHg, 53 mmHg, 40 mmHg and 28 mmHg as shown in FIG. In the first pressing cycle (10 seconds), the primary pressure, then the maximum secondary pressure (109 mmHg), then the pressure release, then the primary pressure, and the secondary pressure is sequentially applied from the next pressing cycle. I lowered it. The maximum secondary pressure was applied again in the next pressing cycle following the minimum secondary pressure applied cycle.

  FIG. 5 shows a result of an example of blood fluidity evaluation of a healthy person regarding a certain scleroderma. (A)-(F) shows the result in the pushing cycle which applies the maximum secondary pressure to the result in the pushing cycle which applies the minimum secondary pressure in order. FIG. 5 shows the result of measuring the time change of the blood volume in the test site using light scattering. It has been shown that blood volume increases with a decrease in secondary pressure.

  FIG. 6 shows the results of a blood fluidity evaluation example of 4 persons. The measurement profile is the same as above. In FIG. 6, the time change of the blood volume when various secondary pressures are applied is plotted in the same graph for each measurer. In the healthy subjects A and B, the change in blood volume is remarkably confirmed depending on the value of the secondary pressure, whereas in the scleroderma patient C and the scleroderma patient D, the secondary pressure It was found that even if the value was changed, the change in blood volume was minute, and by this measurement, discrimination of scleroderma could be made very clearly.

According to the present invention, the fluidity of blood can be easily evaluated from the outside, and it is possible to meet the demand for helping to maintain health.
The exemplary embodiments of the present invention have been described above in detail. Various modifications and additions can be made without departing from the spirit and scope of the present invention. Therefore, the above description is illustrative and not intended to limit the scope of the invention.

10 unit for evaluating blood fluidity 11 unit for pulse measurement 100 test site 110 pulse measurement site 21 measurement sensor 22 pulse synchronization optical sensor

Claims (7)

A method for assessing blood fluidity, comprising:
The pressing member is pressed against the test site of the subject with the pressure of the primary pressure, the blood in the test site is allowed to flow out to the periphery of the test site, and then the pressure of pressing the pressing member is reduced to the secondary pressure, Then, the pressure for pressing the pressing member is released, and then the pressing pressure for pressing the pressing member is increased to the primary pressure. Has a step of measuring using scattering,
The secondary pressure value has at least two different values over multiple pressing cycles,
Way .   The method according to claim 1, wherein the time required for one pressing cycle is 5 to 15 seconds.   The secondary pressure has 4 to 10 different values including the maximum secondary pressure and the minimum secondary pressure, and from the maximum secondary pressure to the minimum secondary pressure with the execution of the pressing cycle. 2. The method of claim 1, wherein the secondary pressures are applied in decreasing order of pressure, and the maximum secondary pressure is applied in the pressing cycle following the pressing cycle that applied the minimum secondary pressure.   The method according to claim 1, further comprising measuring the pulse of the subject and controlling the driving of the pressing member based on the acquired pulse measurement data. The time to press the pressing member to the test site with the pressure of the primary pressure is set to a length of 1 to 3 beats based on the measurement data of the pulse, and the time to press the pressing member to the test site with the pressure of the secondary pressure. 5. The method according to claim 4, wherein the driving of the pressing member is controlled so that the length is 1 to 5 beats based on the pulse measurement data.   The method according to claim 3, further comprising measuring the pulse of the subject and controlling the driving of the pressing member based on the acquired pulse measurement data. The time to press the pressing member to the test site with the pressure of the primary pressure is set to a length of 1 to 3 beats based on the measurement data of the pulse, and the time to press the pressing member to the test site with the pressure of the secondary pressure. 7. The method according to claim 6, wherein the driving of the pressing member is controlled so that the length becomes 1 to 5 beats based on the measurement data of the pulse.

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