JP2014176744A - Blood pressure measuring device and blood pressure measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pulsation pressure measuring device that can be worn continuously, capable of performing calibration easily and simply without using a special measuring instrument separately when continuously measuring the pressure of a fluid flowing in a conduit.SOLUTION: A fluid pulsation pressure measuring device equipped with at least two conduit diameter sensors 1 and 2 arranged apart from each other measures a reflection arrival time at signal calculation parts 11 and 21 by transmitting and receiving a wave to and from a conduit present in an object to be measured by one sensor or the other sensor, derives a water head difference by height position determination parts 24 and 28 based on a distance between each sensor, derives an amount of change in the conduit and a diameter difference of the conduit by a pulse pressure signal calculation part 31, and finds a pressure difference between the maximum value and the minimum value of the fluid pressure in the conduit calibrated using the water head difference.

Description

  The present invention relates to a fluid pulsation pressure measurement device, a fluid pulsation pressure measurement method, a pulsation pressure measurement device, and a pulsation pressure measurement method.

As a means of obtaining the pulsation pressure of the fluid flowing in the conduit, instead of measuring the pulsation pressure of the flowing fluid by installing a sensor or the like directly in the conduit, it uses a wave such as a microwave or an ultrasonic wave. There is a need for a technique for measuring the state in a conduit from the outside.
In particular, in a living body, as a method for measuring a state inside the body from outside the body, non-invasive measurement without pain is required, and a method for measuring a state in a blood vessel, for example, a pulse pressure using an ultrasonic wave has been proposed.

  A pulse pressure value is attracting attention as an index for observing the degree of progression of arteriosclerosis in a state representing a state in a blood vessel of a living body. The pulse pressure value is obtained from the difference between the systolic blood pressure (maximum blood pressure) and the diastolic blood pressure (minimum blood pressure). In the local part of the artery, the maximum diameter and the minimum diameter are obtained, the parameter values are given to the nonlinear function, and the diameter at each time point input is converted by the nonlinear function. The pressure is calculated (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2004-041382

  As described in Japanese Patent Application Laid-Open No. H10-228707, calibration with a cuff type sphygmomanometer is required to calculate a blood pressure value using conventional ultrasonic waves. This is a 24 hour free action, considering blood pressure measurement (24 hour ABPM) and continuous blood pressure measurement every beat, there are inconveniences such as wearing a cuff at all times or carrying it around in time, There is a risk that it will be difficult to use in sending.

  Moreover, in addition to the need for calibration with a cuff type sphygmomanometer, there is a possibility that the calibration is required regularly (about 30 minutes to 1 hour).

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] Provided with at least two measuring units that are spaced apart from each other along a direction perpendicular to the longitudinal direction of the flexible belt-like base material, and a control unit that controls the measuring units. In the fluid pulsation pressure measuring apparatus, the measurement unit receives a measurement medium transmitting unit that sends the measurement medium to the measurement target unit, and a measurement medium that receives at least a part of the measurement medium returned from the measurement target unit And the control unit measures the diameter of the conduit existing in the measurement target unit by one and the other measurement units, and the amount of change in the conduit diameter measured by the at least one measurement unit. A difference in the diameter of the conduit between the one measurement unit and the other measurement unit, a water head difference derived based on the distance between the at least two measurement units, and the head derived based on the water head difference Maximum fluid pressure in the measurement target part Fluid pulsation pressure measuring apparatus characterized by obtaining a difference between the value and the minimum value.

  According to this, by calculating the coefficient value obtained from the diameter of the conduit in the at least two measuring units and the distance between the measuring units, it is possible to easily obtain the pressure of the fluid without special calibration thereafter. it can.

  Application Example 2 The fluid pulsation pressure measuring device according to claim 1, further comprising a height difference determining unit that determines a distance in the gravity direction between the two measuring units.

  According to this, the height difference which is one element at the time of calculating | requiring water head pressure can be determined easily.

  Application Example 3 In the fluid pulsation pressure measuring device, the distance in the gravitational (vertical) direction between the at least two measuring units is the distance between the at least two measuring units and the at least two measuring units. A fluid pulsation pressure measuring device which is calculated by an inclination angle with respect to a gravity direction of a measuring unit.

  According to this, it is possible to easily measure the height difference, which is one element when obtaining the hydraulic head pressure, without depending on the spatial arrangement of the two measuring units.

  Application Example 4 With the first part of the measurement target portion positioned at the height of the pressure reference plane of the fluid, the time change of the conduit diameter between the predetermined first part and the predetermined second part is measured. Determining the average conduit diameter, determining the conduit diameter at the highest pressure and the lowest pressure from the change in the conduit diameter over time at the first location, and calculating the average diameter at the first location. The step of obtaining the amount of change in the average conduit diameter using the tube diameter and the average conduit diameter in the second portion, and in the state, measuring the height difference between the first portion and the second portion A difference measuring step, a step of obtaining a head pressure between the first portion and the second portion using the height difference, a head pressure, a change amount of the average conduit diameter, and a guide at the maximum pressure. Obtaining a pressure difference between the maximum pressure and the minimum pressure using the pipe diameter and the diameter of the conduit at the minimum pressure. Body pulsating pressure measurement method.

  According to this, it is possible to accurately measure the fluid pressure difference in the conduit without using another special measuring instrument for calibration.

  Application Example 5 Controlling at least two blood vessel diameter measuring units that are spaced apart from each other along a direction perpendicular to the longitudinal direction of a flexible belt-like base material, and the blood vessel diameter measuring unit A pulse pressure measuring device including a control unit, wherein the blood vessel diameter measuring unit transmits a ultrasonic wave to a blood vessel inside the living body, and the ultrasonic wave reflected from the blood vessel inside the living body returns. A receiving unit that receives at least a portion, and the control unit measures a blood vessel diameter inside the living body by one and the other blood vessel diameter measuring unit, and the measurement is performed by the at least one blood vessel diameter measuring unit. A change in blood vessel diameter, a difference in the blood vessel diameter between the one blood vessel diameter measurement unit and the other blood vessel diameter measurement unit, and a head difference derived based on a distance between the at least two blood vessel diameter measurement units, And derived based on the water head difference Pulse pressure measuring apparatus characterized by determining the pulse pressure which is the difference between the maximum value and the minimum value of the pressure of the blood (blood pressure) flowing through the blood vessel in the organism.

  According to this, the pulse pressure measuring device which can obtain | require a pulse pressure easily after that by calculating | requiring a hydraulic head pressure from the distance between the blood vessel diameter in two blood vessel diameter measurement parts and two blood vessel diameter measurement parts first. Can provide.

  Application Example 6 The pulse pressure measurement device according to the above-described pulse pressure measurement device, further comprising a height difference determination unit that determines a distance in the gravity direction between the two blood vessel diameter measurement units.

  According to this, the height difference which is one element at the time of calculating | requiring water head pressure can be determined easily.

  Application Example 7 In the pulse pressure measuring device, the distance in the gravitational direction between the at least two blood vessel diameter measuring units is the distance between each of the at least two blood vessel diameter measuring units and the at least two blood vessel diameter measuring units. A pulse pressure measuring device calculated by an inclination angle with respect to a gravity direction of a blood vessel diameter measuring unit.

  According to this, it is possible to easily measure the height difference, which is one element when obtaining the hydraulic head pressure, without depending on the spatial arrangement of the two blood vessel diameter measuring units.

  Application Example 8 With the first part of the measurement subject positioned at the height of the blood pressure reference plane, the time variation of the blood vessel diameter between the predetermined first part and the predetermined second part is measured. A step of obtaining an average blood vessel diameter, a step of obtaining a blood vessel diameter at the time of systolic blood pressure and at the time of the systolic blood pressure, from the time change of the blood vessel diameter at the first portion, A step of obtaining an average blood vessel diameter change amount using an average blood vessel diameter at two sites, a height difference measuring step of measuring a height difference between the first site and the second site in the state, and the height A step of obtaining a hydrocephalic pressure between the first part and the second part using the difference, the hydrocephalic pressure, a change amount of the mean blood vessel diameter, a blood vessel diameter at the highest blood pressure, and a blood pressure at the lowest blood pressure. Obtaining a pulse pressure that is a pressure difference between the systolic blood pressure and the systolic blood pressure using the blood vessel diameter. Pulse pressure measurement method to be.

  According to this, it is possible to accurately measure the pulse pressure without using another special measuring instrument for calibration, and it is possible to reduce the load when the measurement subject constantly measures the pulse pressure under free action. .

The external view which shows the state with which the pulse pressure measuring device which concerns on this embodiment was mounted | worn with the human body. Sectional drawing containing the conduit diameter sensor with which the human body which concerns on this embodiment was mounted | worn. The figure which shows the circuit block which concerns on this embodiment. The figure which shows the blood vessel diameter to which the hydraulic head pressure part which concerns on this embodiment was added. The figure which shows the blood-pressure fluctuation | variation and blood-vessel diameter fluctuation | variation which concern on this embodiment. The figure which shows the time change of the blood vessel diameter and blood pressure which concern on this embodiment. The figure which shows the measuring method which concerns on this embodiment.

  Hereinafter, the present embodiment will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  FIG. 1 is an external view showing a state in which the pulse pressure measuring device according to this embodiment is attached to a human body. Here, it is assumed that the fluid pulsation pressure measuring device is used as a pulse pressure measuring device in a human body, and the case of measuring the brachial artery pulse pressure is considered. The conduit diameter sensors 1 and 2 as two measuring parts are attached to the upper arm 6 of the subject 4 using a band made of nylon or the like as a flexible belt-like base material, and the brachial artery (blood vessel) ) By measuring the blood vessel diameter D (see FIG. 2) as the conduit diameter of 3, the blood pressure is obtained as the fluid pressure. Since it is only necessary to fix the conduit diameter sensors 1 and 2 to the measurement site for attachment to the upper arm 6, a sealing material (not shown) having adhesiveness with the skin may be used instead of the band. Desirably, either one of the conduit diameter sensor positions is the same height as the position of the heart 5 of the person to be measured 4 (in this embodiment, the conduit diameter sensor 1). If it is used for constant measurement, the water head pressure correction is unnecessary. However, even if the height position is not the same as that of the heart 5, if the height difference from the heart 5 is obtained in advance, the pulse pressure can be obtained correctly. That is, measurement is possible without using the upper arm 6 as in the embodiment.

  FIG. 2 is a cross-sectional view including conduit diameter sensors 1 and 2 attached to the human body according to the present embodiment. The conduit diameter sensors 1 and 2 of the pulse pressure measuring device 7 according to the present embodiment are attached to the upper arm 6 of the person to be measured 4, transmit waves such as ultrasonic waves to the brachial artery 3, and reflect from the blood vessel wall. By receiving the wave, the blood vessel diameter D is measured from the reflection arrival time.

  FIG. 3 is a diagram illustrating a circuit block according to the present embodiment. The pulse pressure measuring device 7 according to this embodiment includes at least two conduit diameter sensors. The pulse pressure measuring device 7 is attached to the upper arm 6 of the person under measurement 4, measures the blood vessel diameter D of the brachial artery 3, and obtains the pulse pressure from the systolic blood pressure and the diastolic blood pressure.

  At least two conduit diameter sensors provided in the pulse pressure measuring device 7 according to the present embodiment are attached at positions where ultrasonic waves can be applied to the brachial artery 3 inside the brachial arm 6. It is desirable that one of the conduit diameter sensors 1 and 2 is mounted at the same height as the heart 5. The conduit diameter sensor 1 attached to the height H transmits a pulse signal or a burst signal of several M to several tens of MHz from the transmission unit 12, and receives a reflected wave from the wall of the brachial artery 3 at the reception unit 14, The arrival time is measured from the relationship between the transmission wave and the reception wave. The conduit diameter sensor 2 attached to the height L transmits a pulse signal or a burst signal of several M to several tens of MHz from the transmitting unit 16, and receives a reflected wave from the brachial artery 3 wall at the receiving unit 18, The arrival time is measured from the relationship between the transmission wave and the reception wave. The signal calculation unit 11 of the conduit diameter sensor 1 transmits ultrasonic waves to the brachial artery 3 inside the living body and receives reflections from the wall of the brachial artery 3 inside the living body, from transmission to reception. The reflection arrival time difference is detected. The signal calculation unit 21 of the conduit diameter sensor 2 transmits ultrasonic waves to the brachial artery 3 inside the living body and receives reflections from the wall of the brachial artery 3 inside the living body. The reflection arrival time difference is detected.

  The conduit diameter sensor 1 includes a transmission unit 12, a reception unit 14, a drive unit 22, a signal calculation unit 11, and a height position determination unit 24. The conduit diameter sensor 2 includes a transmission unit 16, a reception unit 18, a drive unit 26, a signal calculation unit 21, and a height position determination unit 28. After transmitting an ultrasonic wave from the transmitting unit 12 to the brachial artery 3 inside the living body and receiving a reflected wave from the wall of the brachial artery 3 inside the living body by the receiving unit 14, displacement information relating to the conduit, that is, the wall of the brachial artery 3 A signal including is detected. The drive unit 22 drives the ultrasonic pulse transmitted from the transmission unit 12. The signal calculation unit 11 controls the drive unit 22, the reception unit 14, and the height position determination unit 24, detects the reflection arrival time difference and determines the height position of the conduit diameter sensor 1, and the blood vessel diameter D inside the living body. Ask for. Further, after transmitting an ultrasonic wave from the transmitting unit 16 to the brachial artery 3 inside the living body and receiving a reflected wave from the wall of the brachial artery 3 inside the living body by the receiving unit 18, the displacement related to the conduit, that is, the wall of the brachial artery 3 Detect signals that contain information. The drive unit 26 drives an ultrasonic pulse transmitted from the transmission unit 16. The signal calculation unit 21 controls the drive unit 26, the reception unit 18, and the height position determination unit 28 to detect the reflection arrival time difference and the height position of the conduit diameter sensor 2 to thereby determine the blood vessel diameter D inside the living body. Ask for.

  The pulse pressure measurement device 7 according to the present embodiment includes a pulse pressure signal calculation unit 31, a display unit 32, a switch (SW) 33, an operation unit 34, and a power supply unit 40. The pulse pressure signal calculation unit 31 calculates the pulse pressure of the measurement subject 4 using the calculation results of the signal calculation unit 11 and the signal calculation unit 21. The display unit 32 displays the pulse pressure of the measurement subject 4. It can also be visualized and displayed on a graph or the like. Further, the pulse may be displayed in the same manner. The switch 33 switches supply / cut-off of power from the power supply unit 40 to each functional unit of the pulse pressure measuring device 7. The power supply unit 40 supplies power to each functional unit of the pulse pressure measuring device 7. As the power supply unit 40, for example, a rechargeable secondary battery is assumed. On the display unit 32, the operation unit 34 can display the measured pulse pressure, switch to the pulse, or switch to past logging data display.

  FIG. 4 is a view showing the blood vessel diameter D to which the hydraulic head pressure component is applied according to the present embodiment.

  FIG. 5 is a diagram showing blood pressure fluctuations and blood vessel diameter fluctuations according to the present embodiment. Since it can be considered that the blood vessel diameter D and the blood vessel wall pressure (blood pressure P) change substantially linearly from the solid line of height H and the dotted line of height L, measuring the time change of the blood vessel diameter D makes it possible to reduce the time change of blood pressure. Correlated values are obtained. Since the difference in blood vessel diameter between heights H and L at the same blood pressure is considered to be a difference due to hydrocephalic pressure, the hydrocephalic pressure (ρ) due to difference ΔDm in mean blood vessel diameter and height difference h between heights H and L G · h) and (ρ: density of blood, g: acceleration of gravity) uniquely correspond.

  Next, a method for calculating the systolic blood pressure Psys and the diastolic blood pressure Pdia will be described.

  The systolic blood vessel diameter Dsys and the diastolic blood vessel diameter Ddia at the same height H as the heart 5 position, that is, in a state where correction of the hydrocephalic pressure is not necessary, and at a height L separated from the position of the heart 5 by the height difference h. And ask. Ultrasound is transmitted / received to / from the blood vessel 3 inside the living body, and the systolic blood vessel diameter Dsys and the diastolic blood vessel diameter Ddia are calculated from the difference in reflection arrival time between both blood vessel walls. At the same time, the change over time in the blood vessel diameter D is measured. From the tube law of blood vessels, the blood vessel diameter D and the blood vessel wall pressure (blood pressure) can be approximated approximately linearly when no pressure is applied or fine pressure is applied. At that time, the time change of the blood vessel diameter D is similar to the time change of the blood pressure P (see FIG. 5).

  Compared to the position of the heart 5, an extra pressure corresponding to the hydraulic head pressure is applied to the blood vessel 3 at the same height difference from the height H as the heart 5. That is, when the time change of the blood vessel diameter D is measured at a position where there is a difference in height, the time change of the blood pressure P to which the hydraulic head pressure is added is obtained (see FIG. 5). From this, the change ΔD of the blood vessel diameter D corresponding to the hydrocephalic pressure (ρ · g · h), (ρ: density of blood, g: gravitational acceleration) is known. The change in the blood vessel diameter D in the systole and the diastole can be obtained by measurement, and the pulse pressure ΔP (= Psys−Pdia), which is the blood pressure difference between the systolic blood pressure Psys and the diastole blood pressure Pdia, can be calculated.

  FIG. 6 is a diagram showing temporal changes in blood vessel diameter and blood pressure according to the present embodiment. There are the following methods (a) and (b) for calculating how much the pressure value due to the water head pressure corresponds to the change in the blood vessel diameter D.

  (A) The change of the blood vessel diameter D is measured for about 10 seconds, and the average blood vessel diameter Dm1 at the position of the height H and the average blood vessel diameter Dm2 at the position of the height L are calculated as shown in FIG. . Subsequently, a change ΔDm of the average blood vessel diameter (Dm1, Dm2) is obtained from the equation (1).

ΔDm = Dm2−Dm1 (1)
The blood vessel diameter change ΔD corresponding to the hydraulic head pressure is obtained from the equation (2).

ΔD = ΔDm (2)
Accordingly, when the average systolic blood vessel diameter Dmsys1 and the average diastolic blood vessel diameter Dmdia1 at the position of the height H in FIG. 1 are used, Equation (3) is established when the relationship between the pressure and the blood vessel diameter is considered.

(Psys−Pdia): ρ · g · h = (Dmsys1−Dmdia1): ΔDm (3)
Therefore, the water head pressure (ρ · g · h) is obtained from the equation (4) (see FIG. 6A).

  ρ · g · h = (Psys−Pdia) · ΔDm / (Dmsys1−Dmdia1) (4)

  (B) The change of the blood vessel diameter D is measured for about 10 seconds, and the average systolic blood vessel diameter Dmsys1 and the average diastolic blood vessel diameter Dmdia1 at the position of the height H in FIG. The blood vessel diameter Dmsys2 and the average diastolic blood vessel diameter Dmdia2 are calculated. Subsequently, the change ΔDmsys of the average systolic blood vessel diameter (Dmsys1, Dmsys2) is obtained from the equation (5), and the change ΔDmdia of the average diastolic blood vessel diameter (Dmdia1, Dmdia2) is obtained from the equation (6) (FIG. 6B). )reference).

ΔDmsys = Dmsys2-Dmsys1 (5)
ΔDmdia = Dmdia2-Dmdia1 (6)
Further, taking the average from the above, the blood vessel diameter change ΔD corresponding to the hydraulic head pressure is obtained from the equation (7).

ΔD = (ΔDmsys + ΔDmdia) / 2 (7)
Thereby, when the relationship between the pressure and the blood vessel diameter is considered, Expression (8) is established.

(Psys−Pdia): ρ · g · h = (Dmsys1−Dmdia1): (ΔDmsys + ΔDmdia) / 2 (8)
Therefore, the pulse pressure (Psys−Pdia) is obtained from the equation (9).

  (Psys−Pdia) = 2 · (ρ · g · h) · (Dmsys1−Dmdia1) / (ΔDmsys + ΔDmdia) (9)

  If the hydrocephalic pressure (ρ · g · h) can be calculated, the pulse pressure that is the blood pressure difference (Psys−Pdia) between the systolic actual blood pressure Psys and the diastolic actual blood pressure Pdia can be determined from the above-described relationship only by measuring the blood vessel diameter D. . The calculation of the water head pressure (ρ · g · h) is always performed before the start of continuous measurement, that is, once at the beginning of the day, etc., so that more accurate measurement can be performed. Moreover, since the height difference h between the measurement position heights H and L is an important parameter related to accuracy, it is desirable that the measurement positions be mounted at the same position for each measurement.

  FIG. 7 is a diagram illustrating a measurement method according to the present embodiment.

First, as shown in step S10, the blood vessel diameter D at the positions of heights H and L in FIG. 1 is measured, and at the same time, the average blood vessel diameters Dm1 and Dm2 are calculated. The average blood vessel diameter may be specified within one heartbeat, or a change in blood vessel diameter may be measured for about 10 seconds, and an ensemble average for a plurality of heartbeats may be calculated and acquired.
Next, as shown in step S20, the blood vessel diameter Dmsys1 corresponding to the maximum blood pressure and the blood vessel diameter Dmdia1 corresponding to the minimum blood pressure are calculated from the temporal change in the blood vessel diameter D at the position of the height H measured in step S10. To do.
On the other hand, as shown in step S30, the average blood vessel diameter change ΔDm is calculated from the average blood vessel diameters Dm1 and Dm2 calculated in step S10.
Here, as shown in step S40, the hydraulic head pressure (ρgh) is calculated. Details of the calculation of the water head pressure and the method for determining the height difference h will be described later.
Then, as shown in step S50, a blood pressure difference (Psys−Pdia) between the minimum blood pressure Pdia and the maximum blood pressure Psys is calculated. Using the blood vessel diameter Dmsys1 at the maximum blood pressure Psys and the blood vessel diameter Dmdia1 at the minimum blood pressure Pdia at the position of the height H in FIG. -Pdia) is calculated. Then, as shown in step S60, the measurement result is displayed.
Finally, in the measurement continuation in step S70, as shown in step S80, the pulse pressure is calculated from equation (9) in step S50 by measuring the blood vessel diameter at the position of height H, and is shown in step S60. Display the measurement results as follows.

  Here, a method for determining the water head pressure will be described.

In order to obtain the water head pressure (ρ · g · h), in addition to the gravitational acceleration g (≈9.8 m / s ² ), the blood density and the height difference h are required. Since the density ρ of blood is about 1.055 ± 0.005 g / cm ³ between men and women, the effect on blood pressure is ± 0.00. Since it is several mmHg, it can be regarded as constant here. That is, it is necessary to accurately measure the height difference h in order to accurately determine the water head pressure. As shown in FIG. 1, the height difference h can be obtained by measuring the distance between the conduit diameter sensors 1 and 2 with a ruler in advance. Alternatively, if the conduit diameter sensors 1 and 2 are connected by a fixing member having an arbitrary length, the arbitrary length can be set to a height difference.

  By the way, if the measurement target parts are aligned in the vertical direction, there is no problem in the determination method. However, when the measurement target part is inclined from the vertical direction, an error occurs. In that case, the angle of the conduit diameter sensor 1 or 2 can be detected by an inclination sensor or the like, and the height difference h can be calculated from the distance between the detected angle and the conduit diameter sensors 1 and 2. Or, since the ultra-compact barometric pressure sensor using the latest quartz device has a resolution of 3 cm in height difference, if a barometric sensor that can measure the height difference with a resolution of mm order can be obtained by later high accuracy, May be used to measure h. This is considered to be a necessary technique when the measurement subject performs timely calibration under free action.

  In addition, the said method is an example to the last, and if the height difference h can be calculated | required correctly with a certain method, a hydraulic head pressure can also be determined accurately. Actually, if the height difference h is considered to be about 15 cm at the upper arm, the hydraulic head pressure is about 11.6 mmHg.

  When the blood vessel diameter D is measured, a pulse signal or burst signal of several M to several tens of MHz is transmitted from the transmitters 12 and 16 by the drive units 22 and 26 of the conduit diameter sensors 1 and 2 shown in FIG. The reflected waves from the blood vessel wall are received by the units 14 and 18, the reflection arrival times are measured by the signal calculation units 11 and 21, and the blood vessel diameter D is calculated. If the reflected wave arrival time is 1.73 μs and the sound velocity inside the living body is 1500 m / s, the blood vessel diameter D can be calculated as 2.6 mm. For example, a piezoelectric element may be used for transmitting and receiving ultrasonic waves. Furthermore, as a method for measuring the blood vessel diameter D, an echo tracking method for tracking a blood vessel wall or the like based on an echo signal obtained from an ultrasonic beam is known. By the echo tracking method, the displacement of the blood vessel wall or the like can be measured with an accuracy of about several μm below the wavelength of the ultrasonic wave.

  In this embodiment, an ultrasonic wave is used as a measurement medium. However, the measurement medium is not limited to this, and a radio wave including a microwave, a laser, a coherent light, or the like may be used.

  In the present embodiment, the height H of the conduit diameter sensor 1 is set to the height position of the heart 5, but even if the height H and the height of the heart 5 are different, the height difference from the heart 5 is obtained in advance. In this case, the blood pressure can be calculated by adding and subtracting the head pressure as in the above embodiment. In the present embodiment, the measurement target is assumed to be a living body, the conduit is a blood vessel, and the fluid is blood. However, the present embodiment is not limited to this assumption.

  In addition, about embodiment concerning a fluid pulsation pressure measuring device and a fluid pulsation pressure measuring method, it substitutes by the said embodiment.

  DESCRIPTION OF SYMBOLS 1, 2 ... Conduit diameter sensor 3 ... Brachial artery (blood vessel) 4 ... Person to be measured 5 ... Heart 6 ... Upper arm 7 ... Pulse pressure measuring device 11 ... Signal calculation part 21 ... Signal calculation part 31 ... Pulse pressure signal calculation part 32 ... Display unit 33 ... Switch (SW) 34 ... Operation unit 40 ... Power supply unit.

Claims (8)

Fluid pulsation pressure measurement provided with at least two measuring units that are spaced apart from each other along a direction orthogonal to the longitudinal direction of a flexible belt-like substrate and a control unit that controls the measuring unit A device,
The measuring unit is
A measurement medium transmission unit for transmitting the measurement medium to the measurement target unit;
A measurement medium receiving unit for receiving at least a part of the measurement medium returned from the measurement target unit;
With
The controller is
Measure the conduit diameter inherent in the measurement target part by the one and the other measurement part,
Based on the change amount of the conduit diameter measured in the at least one measurement unit, the difference in the conduit diameter between the one measurement unit and the other measurement unit, and the distance between the at least two measurement units A fluid pulsation pressure measuring device that calculates a difference between a water head difference that is derived in this manner and a maximum value and a minimum value of the fluid pressure of the measurement target portion that are derived based on the water head difference. In the fluid pulsation pressure measuring device according to claim 1,
A fluid pulsation pressure measuring device further comprising a height difference determining unit that determines a distance in the gravity direction between the two measuring units. In the fluid pulsation pressure measuring device according to claim 1,
The distance in the gravitational (vertical) direction between the at least two measuring units is calculated by an inclination angle between each of the at least two measuring units and a gravity direction of the at least two measuring units. A fluid pulsation pressure measuring device. In a state where the first part of the measurement target portion is positioned at the height of the pressure reference plane of the fluid, the time change of the pipe diameter between the predetermined first part and the predetermined second part is measured, and the average pipe diameter is measured. The process of seeking
Obtaining the diameter of the conduit at the maximum pressure and the minimum pressure from the change over time in the diameter of the conduit at the first portion;
Determining an average conduit diameter change using the average conduit diameter at the first portion and the average conduit diameter at the second portion;
In the state, a height difference measuring step for measuring a height difference between the first part and the second part,
Determining the hydraulic head pressure between the first part and the second part using the height difference;
Obtaining a pressure difference between the maximum pressure and the minimum pressure using the water head pressure, the amount of change in the average conduit diameter, the conduit diameter at the maximum pressure, and the conduit diameter at the minimum pressure;
A fluid pulsation pressure measuring method characterized by comprising: Provided with at least two blood vessel diameter measuring units spaced apart from each other along a direction perpendicular to the longitudinal direction of the flexible belt-like base material, and a control unit for controlling the blood vessel diameter measuring unit A pulse pressure measuring device,
The blood vessel diameter measuring unit
A transmitter for sending ultrasonic waves to a blood vessel inside the living body;
A receiving unit that receives at least a part of the ultrasound reflected from the blood vessel inside the living body; and
With
The controller is
The blood vessel diameter inside the living body is measured by the one and the other blood vessel diameter measuring unit,
The amount of change in the blood vessel diameter measured in the at least one blood vessel diameter measuring unit, the difference in blood vessel diameter between the one blood vessel diameter measuring unit and the other blood vessel diameter measuring unit, and the at least two blood vessel diameter measuring units The head pressure difference derived based on the distance between the head and the pulse pressure, which is the difference between the maximum value and the minimum value of the blood pressure (blood pressure) flowing through the blood vessel inside the living body, which is derived based on the head difference, is obtained. A pulse pressure measuring device characterized by that. In the pulse pressure measuring device according to claim 5,
A pulse pressure measuring device further comprising a height difference determining unit for determining a distance in a gravity direction between the two blood vessel diameter measuring units. In the pulse pressure measuring device according to claim 5,
The distance in the gravitational direction between the at least two blood vessel diameter measuring units is calculated by the inclination angle between the distance between the at least two blood vessel diameter measuring units and the gravity direction of the at least two blood vessel diameter measuring units. A pulse pressure measuring device characterized by that. With the first part of the person being measured positioned at the height of the blood pressure reference plane, the time variation of the blood vessel diameter between the predetermined first part and the predetermined second part is measured to obtain the average blood vessel diameter. Process,
From the time change of the blood vessel diameter at the first site, obtaining the blood vessel diameter at the highest blood pressure and the lowest blood pressure;
Determining the average blood vessel diameter variation using the average blood vessel diameter at the first site and the average blood vessel size at the second site;
In the state, a height difference measuring step for measuring a height difference between the first part and the second part,
Determining the hydraulic head pressure between the first part and the second part using the height difference;
Obtaining a pulse pressure that is a pressure difference between the highest blood pressure and the lowest blood pressure using the hydrocephalic pressure, the amount of change in the average blood vessel diameter, the blood vessel diameter at the highest blood pressure, and the blood vessel diameter at the lowest blood pressure;
A method for measuring pulse pressure, comprising:

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