A blood pressure measurement system with motion compensation

Abstract

The present invention discloses a blood pressure measurement system that introduces motion compensation. The system comprises a data acquisition module, a first calculation module, a second calculation module and a blood pressure detection module. The system can collect the pressure in the cuff and the pulse wave curve based on the oscillometric linear deflation technology, extract the motion intensity curve according to the pressure curve, perform motion compensation on the pulse wave curve, perform window integration on the pulse wave curve after motion compensation to obtain the pulse wave energy curve, and finally obtain the systolic pressure / diastolic pressure parameters according to the formula detection.

Description

Technical Field

[0001] The invention belongs to the technical field of blood pressure measurement, and relates to a blood pressure measurement system introducing motion compensation. Background Art

[0002] Blood pressure is an important physiological parameter that reflects the state of the cardiovascular system. It is an important basis for clinically diagnosing diseases, observing treatment effects, and making prognostic judgments.

[0003] Blood pressure measurement is generally achieved through invasive or non-invasive methods. The invasive method is mainly used for perioperative measurement and is not suitable for widespread measurement. The non-invasive method obtains the measurement signal through various indirect means and interprets it to obtain the blood pressure value. It has a wide range of applications. The most commonly used measurement methods are the Korotkoff sound method and the oscillometric method.

[0004] The Korotkoff sound method determines the systolic and diastolic blood pressure values ​​by the sound changes during the cuff inflation and deflation process. Since the sound is easily affected by external sound interference, it is generally not suitable for electronic blood pressure measurement. The oscillometric method measures the pressure and pulse wave curve during the cuff inflation and deflation process. Its measurement technology is simple and not easily affected by external sound interference. Therefore, most electronic blood pressure monitors, non-invasive blood pressure monitors of medical monitors, and dynamic blood pressure monitors use the oscillometric method for measurement.

[0005] During the oscillometric measurement process, it is easy to be disturbed by the patient's movement, especially the arm movement interference, which may cause the measurement result to be distorted or the measurement to fail. In the field of dynamic blood pressure measurement, this problem is particularly serious. Therefore, filtering out the oscillometric motion interference is an extremely important part of the blood pressure detection algorithm.

[0006] In addition, most current blood pressure detection products use the amplitude coefficient method to measure blood pressure, that is, by finding the pulse wave envelope vertex, the systolic and diastolic pressure positions corresponding to the pulse wave envelope are obtained according to the empirical formula to obtain the blood pressure measurement value. This type of method generally requires obtaining the pulse wave envelope curve by detecting the pulse wave peak position, which is easy to cause misdetection of the pulse wave peak position in the case of motion interference, affecting the calculation of the pulse wave envelope curve, and thus resulting in low blood pressure measurement accuracy. Summary of the invention

[0007] The first objective of the present invention is to address the deficiencies of the prior art and to propose a blood pressure measurement system that introduces motion compensation.

[0008] A blood pressure measurement system introducing motion compensation, comprising:

[0009] A data acquisition module, used to collect the pressure in the cuff and the pulse wave curve using an oscillometric linear deflation technique;

[0010] A first calculation module, including a motion intensity curve calculation unit and a pulse wave curve processing unit;

[0011] The exercise intensity curve calculation unit is used to extract the exercise intensity curve according to the pressure curve collected by the data collection module; specifically:

[0012] The pressure curve is processed using formula (1) to obtain the exercise intensity curve:

[0013]

[0014] Where y(n) represents the motion intensity value at the nth sampling point, x(n) represents the pressure value at the nth sampling point, and B, A, and M are weight coefficients respectively;

[0015] The pulse wave curve processing unit is used to perform motion compensation on the pulse wave curve collected by the data collection module according to the motion intensity value obtained by the motion intensity curve calculation unit; specifically:

[0016] For each sampling point of the pulse wave curve, the formula (2) and (3) are used to calculate and perform motion compensation:

[0017]

[0018] f(n)=b2×p(n)+b1×p(n-1)+b2×p(n-2)-a1×f(n-1)-a2×f(n-2) (3)

[0019] Wherein, z(n) represents the pulse wave amplitude at the nth sampling point, y(n) represents the motion intensity value at the nth sampling point, p(n) represents the intermediate value of the pulse wave compensation operation at the nth sampling point, f(n) represents the final value of the pulse wave motion compensation at the nth sampling point, and b1, b2, a1, and a2 are weight coefficients;

[0020] The second calculation module is used to calculate the pulse wave energy curve according to the motion-compensated pulse wave curve obtained by the first calculation module; specifically:

[0021] The pulse wave curve after motion compensation is window-integrated using formula (4) to obtain the pulse wave energy curve:

[0022]

[0023] Wherein, w(n) represents the pulse wave energy amplitude at the nth sampling point, N represents the window integration width, f(n) represents the pulse wave amplitude at the nth sampling point after motion compensation, f(n-(N-1)) represents the pulse wave amplitude at the nth sampling point after the n-(N-1)th motion compensation, and n>N-1;

[0024] The blood pressure detection module is used to measure the systolic pressure / diastolic pressure of the pulse wave energy curve after the window integration processing of the second calculation module; specifically:

[0025] On the pulse wave energy curve, the systolic / diastolic pressure parameters are measured according to the following formulas (5)-(6):

[0026]

[0027]

[0028] Among them, w(s) represents the pulse wave energy amplitude corresponding to systolic pressure, w(m) represents the maximum pulse wave energy amplitude, w(d) represents the pulse wave energy amplitude corresponding to diastolic pressure, K1 and K2 are preset values, K1 ranges from 0.45 to 0.49, and K2 ranges from 0.79 to 0.88;

[0029] Find the positions of w(s) and w(d) on the pressure curve. The pressure values ​​corresponding to these positions are the systolic pressure and diastolic pressure, respectively.

[0030] A second object of the present invention is to provide an electronic device, comprising a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor executes the machine executable instructions to implement the blood pressure measurement system.

[0031] A third object of the present invention is to provide a machine-readable storage medium storing machine-executable instructions, which, when called and executed by a processor, prompt the processor to implement the blood pressure measurement system.

[0032] The beneficial effects of the present invention are:

[0033] The present invention introduces a motion compensation algorithm, which can greatly eliminate the influence of motion interference. The proposed pulse wave energy curve does not need to detect characteristic parameters such as the pulse wave peak, avoiding the problem of measurement error or error caused by characteristic point detection errors, thereby obtaining more accurate and effective blood pressure measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of motion compensation effect, wherein (A) is the motion intensity curve obtained in step S2.1, (B) is the pulse wave curve before motion compensation, and (C) is the pulse wave curve after motion compensation obtained after processing in step S2.2.

[0035] Figure 2 Schematic diagram of pulse wave energy curve and blood pressure characteristic point detection, wherein (A) is the pressure curve, (B) is the pulse wave energy curve obtained in step S3, (C) is the pulse wave curve after motion compensation, Ws , W m , W d The pulse wave energy amplitude positions corresponding to the systolic pressure, maximum amplitude, and diastolic pressure described in step S4, respectively, and SBP and DBP are Ws and Ws described in step S4. d The corresponding pressure wave positions are the final measurements of systolic and diastolic blood pressure. DETAILED DESCRIPTION

[0036] The present application is further described below in conjunction with the embodiments and drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0037] A blood pressure measurement system with motion compensation, comprising a data acquisition module, a first calculation module, a second calculation module and a blood pressure detection module, wherein:

[0038] The data acquisition module is based on oscillometric linear deflation technology, that is, after the cuff is inflated to block arterial blood flow, the cuff is deflated through linear control technology. During the deflation process, as the cuff pressure decreases, the pulse wave amplitude changes from weak to strong, and then from strong to weak. The pressure and pulse wave curves generated in this process can be obtained by the data acquisition module for subsequent processing;

[0039] The first calculation module includes a motion intensity curve calculation unit and a pulse wave curve processing unit. The motion intensity curve calculation unit extracts the motion intensity curve according to the pressure curve collected by the data collection module. The specific working process is:

[0040] The pressure curve is processed using formula (1) to obtain the exercise intensity curve. The exercise intensity curve is as follows: Figure 1 (A) as shown:

[0041]

[0042] Among them, y(n) represents the motion intensity value of the nth sampling point, x(n) represents the pressure value of the nth sampling point, and B, A, and M are weight coefficients respectively.

[0043] In one embodiment of the present invention, the typical value of parameter B is 0.568, the typical value of parameter A is -0.135, and the typical value of M is 12.

[0044] The pulse wave curve processing unit is used to perform motion compensation on the pulse wave curve collected by the data collection module according to the exercise intensity value obtained by the exercise intensity curve calculation unit. The specific working process is:

[0045] For each point of the pulse wave curve, the formula (2) and (3) are used to calculate and perform motion compensation:

[0046]

[0047] f(n)=b2×p(n)+b1×p(n-1)+b2×p(n-2)-a1×f(n-1)-a2×f(n-2) (3)

[0048] Among them, z(n) represents the pulse wave amplitude of the nth sampling point, y(n) represents the motion intensity value of the nth sampling point, p(n) represents the intermediate value of the pulse wave compensation operation of the nth sampling point, f(n) represents the final value of the pulse wave motion compensation of the nth sampling point, and b1, b2, a1, and a2 are weight coefficients.

[0049] In one embodiment of the present invention, a typical value of parameter b1 is 0.0256, a typical value of parameter b2 is 0.0128, a typical value of parameter a1 is 1.6556, and a typical value of parameter a2 is -0.7068.

[0050] The pulse wave curve before motion compensation is as follows Figure 1 (B) shows the pulse wave curve after motion compensation. Figure 1 (C) shown.

[0051] The second calculation module is used to calculate the pulse wave energy curve according to the motion-compensated pulse wave curve obtained by the first calculation module. The specific working process is:

[0052] The pulse wave curve after motion compensation is window-integrated using formula (4) to obtain the pulse wave energy curve. Figure 2 (B) as shown:

[0053]

[0054] Wherein, w(n) represents the pulse wave energy amplitude at the nth sampling point, N represents the window integration width, f(n) represents the nth pulse wave amplitude after motion compensation, f(n-(N-1)) represents the nth pulse wave amplitude after the n-(N-1)th motion compensation, and n>N-1.

[0055] In one embodiment of the present invention, a typical value of the parameter N is 128.

[0056] The blood pressure detection module is used to measure the systolic pressure / diastolic pressure of the pulse wave energy curve after the window integration processing of the second calculation module; specifically:

[0057] On the pulse wave energy curve, the systolic / diastolic blood pressure parameters are measured according to the following empirical formula:

[0058]

[0059]

[0060] Among them, w(s) represents the pulse wave energy amplitude corresponding to systolic pressure, w(m) represents the maximum pulse wave energy amplitude, w(d) represents the pulse wave energy amplitude corresponding to diastolic pressure, K1 and K2 are fixed coefficients, K1 is generally in the range of 0.45 to 0.49, and K2 is generally in the range of 0.79 to 0.88.

[0061] In one embodiment of the present invention, the value of K1 is 0.46, and the value of K2 is 0.82. According to the values ​​of K1 and K2, the positions of w(s) and w(d) can be found in the pulse wave energy curve, as shown in FIG. Figure 2 As shown, W s , W m , W d The pulse wave energy amplitude positions corresponding to systolic pressure, maximum amplitude, and diastolic pressure, respectively, SBP and DBP are Ws and W d The corresponding pressure wave positions are the final measurements of systolic and diastolic blood pressure.

[0062] It can be seen from the embodiments of the present invention that the blood pressure measurement process does not need to detect characteristic parameters such as the pulse wave peak, thereby avoiding the problem of measurement errors or errors caused by characteristic point detection errors, thereby obtaining more accurate and effective blood pressure measurement results.

Claims

1. A blood pressure measurement system introducing motion compensation, characterized in that: include: A data acquisition module, used to collect the pressure in the cuff and the pulse wave curve using an oscillometric linear deflation technique; A first calculation module, including a motion intensity curve calculation unit and a pulse wave curve processing unit; The exercise intensity curve calculation unit is used to extract the exercise intensity curve according to the pressure curve collected by the data collection module; specifically: The pressure curve is processed using formula (1) to obtain the exercise intensity curve: Where y(n) represents the motion intensity value at the nth sampling point, x(n) represents the pressure value at the nth sampling point, and B, A, and M are weight coefficients respectively; The pulse wave curve processing unit is used to perform motion compensation on the pulse wave curve collected by the data collection module according to the motion intensity value obtained by the motion intensity curve calculation unit; specifically: For each sampling point of the pulse wave curve, the formula (2) and (3) are used to calculate and perform motion compensation: f(n)=b2×p(n)+b1×p(n-1)+b2×p(n-2)-a1×f(n-1)-a2×f(n-2) (3) Wherein, z(n) represents the pulse wave amplitude at the nth sampling point, y(n) represents the motion intensity value at the nth sampling point, p(n) represents the intermediate value of the pulse wave compensation operation at the nth sampling point, f(n) represents the final value of the pulse wave motion compensation at the nth sampling point, and b1, b2, a1, and a2 are weight coefficients; The second calculation module is used to calculate the pulse wave energy curve according to the motion-compensated pulse wave curve obtained by the first calculation module; specifically: The pulse wave curve after motion compensation is window-integrated using formula (4) to obtain the pulse wave energy curve: Wherein, w(n) represents the pulse wave energy amplitude at the nth sampling point, N represents the window integration width, f(n) represents the pulse wave amplitude at the nth sampling point after motion compensation, f(n-(N-1)) represents the pulse wave amplitude at the nth sampling point after the n-(N-1)th motion compensation, and n>N-1; The blood pressure detection module is used to measure the systolic pressure / diastolic pressure of the pulse wave energy curve after the window integration processing of the second calculation module; specifically: On the pulse wave energy curve, the systolic / diastolic pressure parameters are measured according to the following formulas (5)-(6): Among them, w(s) represents the pulse wave energy amplitude corresponding to systolic pressure, w(m) represents the maximum pulse wave energy amplitude, w(d) represents the pulse wave energy amplitude corresponding to diastolic pressure, K1 and K2 are preset values; Find the positions of w(s) and w(d) on the pressure curve. The pressure values ​​corresponding to these positions are the systolic pressure and diastolic pressure, respectively.

2. The system according to claim 1, characterized in that: The value range of K1 is 0.45~0.

49.

3. The system according to claim 1 or 2, characterized in that: The value range of K2 is 0.79~0.88.

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