JP2005152449A - Evaluation apparatus, calculation apparatus and calculation program for degree of vascular sclerosis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus, or the like, suitable to evaluate a degree of vascular sclerosis at each physical part and to calculate it, related to the apparatus to evaluate and calculate the degree of vascular sclerosis. <P>SOLUTION: A pulse wave velocity PWV and a blood pressure (systolic pressure Ps and diastolic pressure Pd) of a part to be measured are measured, and an evaluation value indicating the degree of vascular sclerosis at the part to be measured is calculated and outputted based on an operation expression including PWV<SP>2</SP>× ln (Ps/Pd). In this case, it is desirable to establish an operation expression which produces the same validation value as that of PWV evaluated in a conventional method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vascular sclerosis degree evaluation apparatus and a vascular sclerosis degree calculation apparatus for evaluating or calculating a vascular sclerosis degree, and a vascular sclerosis degree that is executed in an arithmetic processing device and operates as the vascular sclerosis degree calculating device. It relates to a calculation program.

  In recent years, with the increasing aging society, early diagnosis and treatment of early treatment of arteriosclerotic diseases are urgently needed. To this end, first, it is necessary to correctly measure and evaluate how far arteriosclerosis has progressed.

  As one of the techniques for non-invasive quantitative diagnosis of arteriosclerosis, there is known an aortic pulse wave velocity test method for measuring a pulse wave velocity (PWV) which is a propagation velocity of a pulse wave between two points of the aorta. It has been.

  It is known that the pulse wave velocity is fast in a hard substance, slow in a soft substance, and a healthy artery wall is soft and elastic, and an arteriosclerotic blood vessel wall is hard and brittle. The aortic pulse wave velocity test method uses this property, and roughly speaking, the propagation velocity of the pulse wave between two points of the aorta is measured, and the higher the velocity, the more diagnosed the arteriosclerosis is. To do. This pulse wave velocity (PWV) is usually expressed in units of m / sec.

  FIG. 1 is a schematic diagram illustrating an example of a pulse wave velocity measurement method. The pulse wave velocity measuring method shown in FIG. 1 is a measuring method called a Frank method.

  Here, as shown in FIG. 1A, two pulse wave sensors are used to measure the pulse waves of the carotid artery and the femoral artery, respectively. Further, distances a and b + c from the aortic valve opening to each pulse wave measurement point are measured. The measurement between the aortic valve opening and the pulse wave sensor for measuring the femoral artery with a broken line (distance b and distance c) without taking a straight line is based on a path along which the aorta extends.

  FIG. 1B shows the carotid artery wave (a) and the femoral artery wave (b) measured by each pulse wave sensor.

  A time T between predetermined rising points of these pulse waves, for example, points rising by 1/5 of the peak value is obtained.

  Thus, by obtaining the distances a, b, c and time T, the pulse wave velocity PWV is

Is required.

  Patent Document 1 discloses an improved technique based on the above pulse wave velocity measurement method. In Patent Document 1, pulse waves of the brachial artery and ankle arteries are measured instead of the pulse waves of the carotid artery and the femoral artery.

  FIG. 2 is a schematic view showing another example of the pulse wave velocity measuring method. The pulse wave velocity measuring method shown in FIG. 2 is a measuring method called the Yoshimura method.

  Similar to the Frank method shown in FIG. 1, in addition to the two sensors for measuring the pulse waves of the carotid artery and the femoral artery, sensors are also arranged at the aortic valve opening to measure the starting point of the II sound. Further, the linear distance D between the aortic valve opening and the femoral artery pulse wave measurement sensor is measured. In order to correct the difference between the straight line distance D and the actual path of the artery, the straight line distance D is multiplied by 1.3.

In addition, the time T from the rising timing of the carotid artery wave to the rising edge of the femoral artery wave and the timing of the II sound of the aortic valve opening shown in FIG. The time t until the timing when the sound is captured is measured.

  Thus, by calculating the linear distance D and the times T and t, the pulse wave velocity PWV is

Is required.

  Here, the pulse wave velocity varies depending on the blood pressure. This is because when the blood pressure rises, the blood vessel is pushed and expanded by the blood, and the blood vessel is apparently hardened.

  FIG. 3 is a graph showing the relationship between minimum blood pressure (diastolic pressure) and aortic pulse wave velocity. FIG. 3 shows the relationship between the minimum blood pressure (diastolic pressure) and the aortic pulse wave velocity in 73 cases.

  As shown in FIG. 3, when the blood pressure increases, the aortic pulse wave velocity also increases.

  FIG. 4 is a diagram showing a pulse wave velocity correction curve.

  As shown in FIG. 3, the pulse wave velocity changes depending on the blood pressure. Therefore, a large number of cases as shown in FIG. 3 are statistically analyzed, and a pulse wave velocity correction curve is obtained as shown in FIG. In actual measurement, the pulse wave velocity is measured and the blood pressure is measured, and the measured pulse wave velocity is converted into the pulse wave velocity when the minimum blood pressure (diastolic pressure) is 80 mmHg according to the pulse wave velocity correction curve shown in FIG. To do.

  Also in Patent Document 1, this blood pressure correction is performed.

  By doing so, it does not depend on the blood pressure at the time of measuring the pulse wave of the case. The pulse wave velocity of the case is obtained, and atherosclerosis is diagnosed based on the pulse wave velocity.

Further, Non-Patent Document 1 is cited for later explanation.
Japanese Patent No. 3140007 “Artificial Stiffness and Pulse Wave Velocity Clinical Applications”, Roland Asmar, Michael F .; O'Rourke, Michel Safari 1999 Editions scientifics et medicales Elsevier SAS

  As described above, blood pressure is also measured at the time of measuring the pulse wave velocity, and the measured pulse wave velocity is corrected by the blood pressure. It can be used for diagnosis of various diseases caused by sclerosis.

  Here, arteriosclerosis does not always progress in the same state throughout the whole body, and may differ for each part of the body. Therefore, in order to precisely examine the progress of arteriosclerosis, a measurement method that can freely measure the pulse wave velocity of blood vessels in various parts of the body is preferable.

  However, in the case of the above-described pulse wave velocity measurement method, it is necessary to correct the blood pressure. For this purpose, it is necessary to obtain a correction curve as shown in FIG. 4 in advance with high accuracy. FIG. 4 shows a correction curve when a specific part of the aorta is measured by a specific pulse wave measurement method. The correction curve as shown in FIG. 4 is different for each part of the body. It is extremely difficult to obtain the correction curve for each of various parts of the body with high accuracy. Therefore, conventionally, the pulse wave velocity measuring method has been adopted as a measuring method for measuring a specific part as shown in FIGS.

  In view of the above circumstances, the present invention provides a vascular sclerosis degree evaluation apparatus and a vascular sclerosis degree calculation apparatus suitable for evaluating and calculating the degree of sclerosis of blood vessels in each part of the body, and an arithmetic operation that executes a program. It is an object of the present invention to provide a blood vessel sclerosis degree calculation program for operating a processing apparatus as such a vascular sclerosis degree calculation device.

The blood vessel sclerosis evaluation apparatus of the present invention that achieves the above object obtains a blood pressure composed of a pulse wave velocity measuring unit that obtains a pulse wave velocity PWV of a measurement target region, and a systolic pressure Ps and a diastolic pressure Pd of the measurement target region. Using the blood pressure measurement unit, the pulse wave velocity obtained by the pulse wave velocity measurement unit and the blood pressure obtained by the blood pressure measurement unit,
PWV ²・ ln (Ps / Pd)
An evaluation value calculation unit that calculates an evaluation value that indicates the degree of sclerosis of the blood vessel of the measurement target site based on an arithmetic expression that includes the evaluation value, and an evaluation value output unit that outputs the evaluation value calculated by the evaluation value calculation unit It is characterized by that.

  Here, in the vascular stiffness evaluation apparatus according to the present invention, the evaluation value calculation unit calculates the evaluation value corrected so as to be statistically the same value as the corrected pulse wave velocity corrected based on the blood pressure. It is preferable that the blood pressure measurement unit obtains the blood pressure at the midpoint of the pulse wave measurement target site when the pulse wave velocity measurement unit obtains the pulse wave velocity.

In addition, the blood vessel sclerosis degree calculation apparatus of the present invention that achieves the above object includes data representing the pulse wave velocity PWV of the measurement target region or data for pulse wave velocity calculation, and the systolic pressure Ps and diastolic pressure of the measurement target region. Using a data acquisition unit that acquires data representing blood pressure composed of Pd or data for blood pressure calculation, and data acquired by the data acquisition unit,
PWV ²・ ln (Ps / Pd)
An evaluation value calculation unit that calculates an evaluation value that indicates the degree of sclerosis of the blood vessel of the measurement target site based on an arithmetic expression that includes the evaluation value, and an evaluation value output unit that outputs the evaluation value calculated by the evaluation value calculation unit It is characterized by that.

Furthermore, the blood vessel sclerosis degree calculation program of the present invention that achieves the above object is executed in an arithmetic processing unit that executes the program, and the arithmetic processing unit includes data representing the pulse wave velocity PWV of the measurement target region or pulse wave velocity. A data acquisition unit that acquires data for calculation and data representing blood pressure or blood pressure calculation data including the systolic pressure Ps and the diastolic pressure Pd of the measurement target part, and data acquired by the data acquisition unit are used. ,
PWV ²・ ln (Ps / Pd)
An evaluation value calculation unit that calculates an evaluation value that indicates the degree of sclerosis of the blood vessel of the measurement target site based on an arithmetic expression that includes the evaluation value, and an evaluation value output unit that outputs the evaluation value calculated by the evaluation value calculation unit It operates as a blood vessel sclerosis degree calculation device.

  As described above, the pulse wave velocity (PWV) is measured to diagnose arteriosclerosis. This pulse wave velocity (PWV) is sufficiently accurate with the Moens-Korteweg equation

It is known that it can be represented by the above (see Non-Patent Document 1 mentioned above). Here, k is a constant, and D / ΔD is a blood vessel elastic modulus (D: blood vessel diameter, ΔD: displacement of the blood vessel diameter).

Regarding the blood vessel diameter and blood pressure, the formula (D / ΔD) · ln (Ps / Pd) = β (constant) (4)
Is known to hold (see Non-Patent Document 1 above).

  Here, D / ΔD is the blood vessel elastic modulus (D: blood vessel diameter, ΔD: displacement of blood vessel diameter), as in the case of equation (3), and Ps and Pd are systolic pressure (maximum blood pressure), Diastolic pressure (minimum blood pressure). This β is a constant value for a blood vessel of a specific part of a specific case, and when the blood pressure of that part of the case changes, the blood vessel diameter changes so as to keep the value β constant. Yes.

  Conventionally, both of the above formulas (3) and (4) have been known, but by combining these formulas (3) and (4), the drawback of the pulse wave velocity inspection method, that is, measurement It is necessary to correct the pulse wave velocity using a correction curve as shown in FIG. 4, so that the disadvantage that only the pulse wave velocity inspection of a specific part can be performed can be overcome. There are no examples.

Here, when the above equation (3) is squared and the equation (4) is substituted for D / ΔD in the squared equation (3),
PWV ² · ln (Ps / Pd) = k ² β (5)
This equation (5) only measures PWV, measures blood pressure (systolic pressure (maximum blood pressure) Ps and diastolic pressure (minimum blood pressure) Pd), and substitutes these measurement results into equation (5). This means that k ² β, which is a value corresponding to the measurement site, can be obtained without performing correction according to the correction curve as shown in FIG. In other words, the expression (5) can be adopted as an evaluation value for diagnosing the degree of progression of arteriosclerosis. In order to obtain the evaluation value k ² β, the PWV measurement and the blood pressure measurement are performed as in the conventional case. And that is enough.

  When the inspection method according to the equation (5) is adopted, it is not necessary to obtain a correction curve as shown in FIG. 4 in advance and correct the correction based on the curve. Can also be applied.

Here, it has been described that PWV, Ps, and Pd are measured and k ² β is obtained according to the equation (5). Instead of obtaining k ² β, k is a known constant, and therefore β can be obtained. Alternatively, an arithmetic expression for obtaining a value affected by the left side PWV ² · ln (Ps / Pd) of the expression (5) may be defined, and a value according to the arithmetic expression may be obtained.

  As described above, according to the present invention, it is possible to evaluate and calculate the degree of hardening of blood vessels in each part regardless of the body part.

  Embodiments of the present invention will be described below.

  FIG. 5 is a block diagram showing an embodiment of the vascular stiffness evaluation apparatus of the present invention.

  The vascular stiffness evaluation apparatus 100 includes a pulse wave velocity measurement unit 101, a blood pressure measurement unit 102, an evaluation value calculation unit 103, and an evaluation value output unit 104.

  In the pulse wave velocity measuring unit 101, the pulse wave velocity PWV of the measurement target part is measured by the pulse wave sensor. As described with reference to FIGS. 1 and 2, there are several types of pulse wave velocity measuring methods, but the method is not limited to a specific measuring method here.

  The pulse wave velocity measuring method itself is a well-known technique, and further evaluation explanation is omitted here.

  In the blood pressure measurement unit 102, the systolic pressure (maximum blood pressure) Ps and the diastolic pressure (minimum blood pressure) Pd of the measurement target site are measured by a blood pressure monitor. The blood pressure measurement method itself is also a well-known technique, and detailed description thereof is omitted.

The evaluation value calculation unit 103 uses the pulse wave velocity obtained by the pulse wave velocity measurement unit 101 and the blood pressure obtained by the blood pressure measurement unit 102,
PWV ²・ ln (Ps / Pd)
An evaluation value that indicates the degree of sclerosis of the blood vessel at the measurement target site is calculated based on an arithmetic expression including. Specific examples will be described later.

  The evaluation value output unit 104 outputs the evaluation value calculated by the evaluation value calculation unit. The output mode of the evaluation value is not limited to a specific output mode. For example, the evaluation value is output on the display screen or printed out by a printer. Further, data representing the evaluation value is output to the outside. (Sent).

  FIG. 6 is a block diagram showing an embodiment of the vascular sclerosis degree calculation apparatus of the present invention.

  This vascular sclerosis degree calculation device 200 includes a data acquisition unit 201, an evaluation value calculation unit 202, and an evaluation value output unit 203.

  Compared with the blood vessel sclerosis degree evaluation apparatus 100 shown in FIG. 5, the blood vessel sclerosis degree calculation apparatus 200 does not include the pulse wave velocity measurement unit 101 and the blood pressure measurement unit 102. The pulse wave velocimeter for measuring the pulse wave velocity and the sphygmomanometer for measuring the blood pressure may be existing ones. If an existing pulse wave velocimeter or sphygmomanometer is used, these pulse wave velocimeters The evaluation value may be calculated and output by taking in the pulse wave velocity data and blood pressure data obtained by the sphygmomanometer. The blood vessel sclerosis calculating apparatus 200 of FIG. 6 is configured based on this idea. In the data acquisition unit 201 constituting the vascular sclerosis degree calculation device 200 of FIG. 6, data representing the pulse wave velocity PWV of the measurement target region and data representing the blood pressure (systolic pressure Ps and diastolic pressure Pd) of the measurement target region. Is acquired.

  Alternatively, the data acquisition unit 201 does not directly represent the pulse wave velocity PWV, but data for calculating the pulse wave velocity PWV, for example, as shown in FIG. 1 (B) or FIG. 2 (B). Waveform data representing a waveform may be acquired from the outside, and the pulse wave velocity PWV may be obtained based on the waveform data inside the data acquisition unit 201.

  Similarly, the data acquisition unit 201 acquires the blood pressure calculation data from the outside even if it is not data directly representing the blood pressure, and based on the blood pressure calculation data, the data acquisition unit 201 You may ask for blood pressure.

  The operation of the evaluation value calculation unit 202 and the evaluation value output unit 203 constituting the vascular sclerosis degree calculating device 200 in FIG. 6 is the same as the evaluation value calculating unit 103 and the evaluation value output unit constituting the vascular sclerosis degree evaluating device 100 in FIG. Each operation 104 is the same as each other, and redundant description is omitted.

  In the present embodiment, the vascular sclerosis degree calculation device 200 shown in FIG. 6 is composed of a combination of a computer and a program preceded in the computer. Therefore, first, the configuration of the computer will be described below.

  FIG. 7 is an external view of a computer that operates as an embodiment of the vascular sclerosis calculation apparatus of the present invention.

  The computer 10 includes a main body 11 incorporating a CPU, a RAM, a hard disk and the like, a display 12 that displays a screen on a display screen 12a according to an instruction from the main body 11, and an operator's instruction and character information in the computer. And a mouse 14 for inputting an instruction corresponding to an icon or the like displayed at that position by designating an arbitrary position on the display screen 12a.

  The main body 11 further has an FD loading port 11a and a CDROM loading port 11b into which a flexible disk (FD) 22 (not shown in FIG. 7; see FIG. 8) and the CDROM 20 are loaded in appearance. Inside, an FD drive 116 and a CDROM drive 117 (see FIG. 8) for driving the loaded FD and CDROM are also incorporated.

  Here, the blood vessel sclerosis degree calculation program according to the present invention is stored in the CDROM 20, and this CDROM 20 is loaded into the main body 11 from the CDROM loading port 11b and is stored in the CDROM 20 by the CDROM drive 117. The program is installed in the hard disk of this computer. When the blood vessel sclerosis degree calculation program installed in the hard disk of this computer system is activated, this computer operates as an embodiment of the vascular sclerosis degree calculation apparatus of the present invention.

  FIG. 8 is a hardware configuration diagram of a computer having the appearance shown in FIG.

  Here, there are a central processing unit (CPU) 111, a RAM 112, input interfaces 113a and 113b, a printer interface 114, a hard disk controller 115, an FD drive 116, a CDROM drive 117, a mouse controller 118, a keyboard controller 119, and a display controller 120. They are connected to each other by a bus 110.

  As described with reference to FIG. 7, the FD drive 116 and the CDROM drive 117 are loaded with the FD22 and the CDROM20, and access the loaded FD22 and CDROM20.

  Further, a pulse wave velocimeter (corresponding to the pulse wave velocity measuring unit 101 in FIG. 5) and a sphygmomanometer (corresponding to the blood pressure measuring unit 102 in FIG. 5) are connected to the two input interfaces 113a and 113b, respectively. The pulse wave velocity data and blood pressure data of the measurement target site measured by the pulse wave velocity meter and the blood pressure monitor are input.

  The printer interface 114 is connected to a printer that prints out images and characters on paper, and the blood vessel stiffness evaluation value data calculated inside the computer is sent to the printer via the printer interface 114. The blood vessel sclerosis evaluation value is printed out by the printer.

  5 also shows the hard disk 21 accessed by the hard disk controller 113, the mouse 14 controlled by the mouse controller 116, the keyboard 13 controlled by the keyboard controller 117, and the display 12 controlled by the display controller 118. ing.

  As described above, the blood vessel sclerosis degree calculation program is stored in the CDROM 20, and the blood vessel sclerosis degree calculation program is read from the CD ROM 20 by the CDROM drive 117, and is stored in the hard disk 21 by the hard disk controller 115 via the bus 110. Stored. In actual execution, the blood vessel hardening degree calculation program in the hard disk 21 is loaded onto the RAM 112 and executed by the CPU 111.

  On the display 12, an evaluation value representing the degree of vascular sclerosis calculated in the computer is displayed, and input information from the keyboard 13 and the mouse 14 is displayed.

  FIG. 9 is a conceptual configuration diagram of the blood vessel sclerosis degree calculation program stored in the CD ROM 20 shown in FIGS.

  The blood vessel sclerosis degree calculation program 300 shown here includes a data acquisition unit 301, an evaluation value calculation unit 302, and an evaluation value output unit 303. When the blood vessel sclerosis degree calculation program 300 is installed in the computer 10 shown in FIG. 7 and executed, the operations of the units 301 to 303 constituting the blood vessel sclerosis degree calculation program 300 are as follows. The operation is the same as that of the units 201 to 203 constituting the calculation device 200. That is, the data acquisition unit 201 included in the vascular sclerosis degree calculation device 200 illustrated in FIG. 6 includes a data acquisition unit 301 as a program component included in the vascular sclerosis degree calculation program 300 illustrated in FIG. It is configured by combining with the CPU 111 to be executed and the input interfaces 113a and 113b responsible for data acquisition.

  Moreover, the evaluation value calculation part 202 which comprises the vascular sclerosis degree calculation apparatus 200 shown in FIG. 6 is the evaluation value calculation part 302 as a program component which comprises the vascular sclerosis degree calculation program 300 shown in FIG. It is configured by combining with the CPU 111 or the like that executes the unit 302.

  Furthermore, the evaluation value output unit 203 constituting the vascular sclerosis degree calculation device 200 shown in FIG. 6 includes an evaluation value output unit 303 as a program component constituting the vascular sclerosis degree calculation program 300 shown in FIG. A CPU 111 that executes the unit 303, a display 12 that displays an evaluation value, a display controller 120 that controls the display 12, a printer interface 114 that outputs the evaluation value to a printer, and the like are combined.

  Next, the evaluation value calculation unit 302, which is executed by the CPU 111, that is, the evaluation value calculation unit 302 and the evaluation value calculation unit 103 and 202 constituting the blood vessel hardening degree evaluation device 100 and the blood vessel hardening degree calculation device shown in FIGS. A specific example of evaluation value calculation in (see FIG. 9) will be described.

  Hereinafter, an arithmetic expression for obtaining the evaluation value will be described.

Here, first, as a first step, the evaluation value V1 is
V1 = ln (Ps / Pd) · 1 / k ² · PWV ² (6)
Define with the following formula.

  Here, Ps and Pd are the systolic pressure and diastolic pressure of the measurement target region, k is a known constant, and PWV is the pulse wave velocity of the measurement target region. Here, the pulse wave velocity PWV substituted into the equation (6) is a pulse wave velocity before correction by blood pressure (see FIG. 4).

  FIG. 10 is a diagram showing a correspondence relationship between the pulse wave velocity as the conventional method and the evaluation value V1 based on the above equation (6). The horizontal axis is the pulse wave velocity when the diastolic pressure (minimum blood pressure) is 80 mmHg corrected according to the correction curve shown in FIG. 4, and the vertical axis is the evaluation value V1 calculated based on the equation (6). . Each plotted point represents one case.

  According to the above equation (6), the evaluation value V1 is proportional to the square of PWV and does not hold a linear relationship, but here is approximated by a straight line as shown in FIG. Further, coordinate transformation is performed so that the straight line passes through the origin and becomes a 45 ° diagonal line.

  FIG. 11 is a diagram illustrating a correspondence relationship between the pulse wave velocity (horizontal axis) according to the conventional method and the evaluation value V2 (after coordinate conversion) after such coordinate conversion is performed.

  Here, the pulse wave velocity measuring method described with reference to FIG. 1 and FIG. 2 is a measuring method for measuring pulse waves in the carotid artery and femoral artery, but each case shown in FIGS. 2 shows the correlation between PWV obtained by the measurement method described with reference to 2 and V1 obtained using the equation (6) or V2 obtained using the equation (7).

  Here, for both ankle arteries, pulse waves are measured, and for the other, T + t when the carotid pulse wave is measured and when the brachial artery pulse wave is measured (FIG. 2B). Reference time will be described.

  FIG. 12 is a graph showing the relationship between the time (T + t) when measuring the carotid artery pulse wave (horizontal axis) and the time T + t when measuring the brachial artery pulse wave (vertical axis).

  Although the time on the horizontal axis and the time on the vertical axis are quite approximate, there are some differences.

  Therefore, considering these, as the evaluation value V2,

Is adopted.

Here, L is the blood vessel length in the pulse wave velocity measurement section, and a, b, a1, and b1 are linear equations shown in FIG.
y = ax−b
And the equation of the straight line shown in FIG. 12 is y = a1 · x + b1
Are the values a, b, a1 and b1.

In the example shown in FIGS. 10 and 12, respectively.
a = 2.6908
b = 13.707
a1 = 0.9872
b1 = 0.7627
It is.

  When the arithmetic expression shown in equation (8) is adopted, when the pulse wave of the brachial artery is measured instead of the carotid artery, it is the same value as when the carotid artery is measured, and the conventional method PWV (minimum) An evaluation value V2 having a value equivalent to a blood pressure of 80 mmHg is calculated.

  In the evaluation value calculation units 103, 202, and 302 shown in FIG. 5, FIG. 6, and FIG. 9, the evaluation value V1 expressed by the above equation (6) may be adopted as the evaluation value of the degree of hardening of the blood vessel. It is more preferable to employ the evaluation value V2 represented by the formula (1). One reason is that the burden on the patient is less when measuring the brachial artery and ankle artery than when measuring the pulse wave of the carotid artery and femoral artery, and the degree of hardening of the blood vessel. If an arithmetic expression is defined so that the same evaluation value as that of the conventional method PWV can be obtained when the values are the same, a doctor who is accustomed to the value of the conventional method PWV can refer to the evaluation value and determine arteriosclerosis. This is because it is easy to diagnose various illnesses associated with the disease.

  Next, blood pressure when obtaining an evaluation value using equation (6) or equation (7) will be described.

  Until now, without particularly mentioning details, it is explained that the blood pressure (systolic pressure Ps and diastolic pressure Pd) of the measurement target part is measured and the blood pressure is substituted into the expression (6) or (7). However, it becomes a problem which blood pressure at which point of the measurement target portion is substituted. Specifically, it is preferable to employ the blood pressure at the center point of the section in which the pulse wave velocity PWV is measured.

  FIG. 13 is a diagram showing systematic body blood pressure distribution characteristics.

  The systolic pressure (Ps) and diastolic pressure (Pd) of each part from the valve opening to the wrist joint and ankle joint are different depending on the individual, but Sp increases, Dp slightly decreases, pulse pressure (Pp) increases, Mean blood pressure (Mp) shows an almost unchanged systematic dynamic. Furthermore, Sp and Dp of the upper arm elbow and wrist joint, popliteal portion and ankle joint are almost unchanged. Based on this systemic body blood pressure distribution characteristic, Ps and Pd of a desired part can be obtained from Ps and Pd of the upper arm and ankle joint.

Now, as an example, when calculating blood pressure in the buttocks,
(Psk−Psb) / (l ₁ + l ₂ −la) = (Psi−Psb) / (l ₁ −la)
(L ₁ −la) (Psk−Psb) = (l ₁ + l ₂ −la) (Psi−Psb)
Psk (l ₁ −l ₂ ) −Psb (l ₁ −l ₂ )
= Psi (l ₁ + l ₂ -la) -Psb (l ₁ + l ₂ -la)
Psi (l ₁ + l ₂ −la)
= Psk (l ₁ −l ₂ ) + Psb (l ₁ + l ₂ −la−l ₁ + l ₂ )
= Psk (l ₁ −l ₂ ) + Psb (2l ₂ −la)
Therefore,

Similarly,

It becomes. However, Psk≈Psa and Pdk≈Pda.

  In this way, the blood pressure at the midpoint between the two points at which the pulse wave measurement was performed is calculated, and the midpoint blood pressure thus calculated is substituted into the formula (6) or (7). Is required.

  The evaluation value obtained in this way is displayed on the display screen 12a (see FIG. 7) of the display 12 as described above, or a printer (not shown) via the printer interface 114 (see FIG. 8). To be printed out and used for diagnosis of arteriosclerosis.

  Here, it has been described that the blood pressure at the midpoint between the two points at which the pulse wave measurement was performed is used and the calculated blood pressure is used. However, for example, the blood pressure value of the upper arm may be substituted for simple measurement. Good.

  In the above example, the pulse waves of the brachial artery and ankle arteries are measured. However, in the present invention, the pulse wave measurement part for measuring the pulse wave velocity may be any part capable of detecting the pulse wave. . Examples of the pulse wave measurement site include the neck, the upper arm, the buttocks, the popliteal part, and the ankle part.

  Furthermore, as a pulse wave measurement sensor, there are cuffs used when measuring blood pressure, bag-like air bugs containing air, optical sensors that detect changes in light, amorphous sensors that detect movement (displacement) of the body surface, etc. As is known, any sensor can be used for pulse wave measurement in the present invention.

It is a schematic diagram which shows an example of the pulse wave velocity measuring method. It is a schematic diagram which shows an example of the pulse wave velocity measuring method. It is a graph which shows the relationship between minimum blood pressure (diastolic pressure) and aortic pulse wave velocity. It is the figure which showed the pulse wave velocity correction curve. It is a block diagram which shows one Embodiment of the vascular sclerosis degree evaluation apparatus of this invention. It is a block diagram which shows one Embodiment of the vascular sclerosis degree calculation apparatus of this invention. 1 is an external view of a computer that operates as an embodiment of a vascular sclerosis calculation apparatus according to the present invention. It is a hardware block diagram of the computer which has the external appearance shown in FIG. It is a notional block diagram of the vascular sclerosis degree calculation program memorize | stored in CDROM. It is a figure which shows the correspondence of the pulse wave velocity as a conventional method, and the evaluation value V1 based on said (6) Formula. It is a graph which shows the correspondence of the pulse-wave velocity (horizontal axis) by a conventional method, and evaluation value V2 (after coordinate transformation) after performing coordinate transformation. It is a graph which shows the relationship between time (T + t) (horizontal axis) when measuring the pulse wave of the carotid artery and T + t time (vertical axis) when measuring the pulse wave of the brachial artery. It is the figure which showed the systematic body blood pressure distribution characteristic.

Explanation of symbols

10 Computer 11 Body 12 Display 13 Keyboard 14 Mouse 20 CDROM
DESCRIPTION OF SYMBOLS 100 Vascular sclerosis evaluation apparatus 101 Pulse wave velocity measurement part 102 Blood pressure measurement part 103 Evaluation value calculation part 104 Evaluation value output part 200 Vascular sclerosis degree calculation apparatus 201 Data acquisition part 202 Evaluation value calculation part 203 Evaluation value output part 300 Vascular sclerosis degree Calculation program 301 Data acquisition unit 302 Evaluation value calculation unit 303 Evaluation value output unit

Claims (5)

A pulse wave velocity measuring unit for obtaining a pulse wave velocity PWV of the measurement target part;
A blood pressure measurement unit for obtaining a blood pressure comprising a systolic pressure Ps and a diastolic pressure Pd of a measurement target site;
Using the pulse wave velocity obtained by the pulse wave velocity measurement unit and the blood pressure obtained by the blood pressure measurement unit,
PWV ²・ ln (Ps / Pd)
An evaluation value calculation unit that calculates an evaluation value that indicates the degree of hardening of the blood vessel of the measurement target site based on an arithmetic expression including:
An evaluation value output unit that outputs the evaluation value calculated by the evaluation value calculation unit.   The said evaluation value calculation part calculates the evaluation value correct | amended so that it may become statistically the same value as the correction | amendment pulse wave velocity corrected based on the blood pressure. Vascular sclerosis evaluation device.   The vascular stiffness evaluation apparatus according to claim 1, wherein the blood pressure measurement unit is configured to obtain a blood pressure at an intermediate point of a measurement target site when the pulse wave velocity measurement unit obtains a pulse wave velocity. Data representing the pulse wave velocity PWV of the measurement target region or data for calculating the pulse wave velocity, and data representing blood pressure comprising the systolic pressure Ps and the diastolic pressure Pd of the measurement target region or data for calculating the blood pressure A data acquisition unit to acquire;
Using the data acquired by the data acquisition unit,
PWV ²・ ln (Ps / Pd)
An evaluation value calculation unit that calculates an evaluation value that indicates the degree of hardening of the blood vessel of the measurement target site based on an arithmetic expression including:
An vascular sclerosis degree calculation device comprising: an evaluation value output unit that outputs an evaluation value calculated by the evaluation value calculation unit. It is executed in an arithmetic processing unit that executes a program, and the arithmetic processing unit is
Data representing the pulse wave velocity PWV of the measurement target region or data for calculating the pulse wave velocity, and data representing the blood pressure composed of the systolic pressure Ps and the diastolic pressure Pd of the measurement target region or data for calculating the blood pressure. A data acquisition unit to acquire;
Using the data acquired by the data acquisition unit,
PWV ²・ ln (Ps / Pd)
An evaluation value calculation unit that calculates an evaluation value that indicates the degree of hardening of the blood vessel of the measurement target site based on an arithmetic expression including:
A blood vessel sclerosis degree calculation program that operates as a vascular sclerosis degree calculation device including an evaluation value output unit that outputs an evaluation value calculated by the evaluation value calculation unit.

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