Blood pressure measurement compensation method, device and apparatus for rapid blood pressure changes

Abstract

The present invention discloses a method, device, and apparatus for compensating for blood pressure measurement with rapid changes in blood pressure, comprising: obtaining a photoplethysmography signal obtained by measuring blood pressure; extracting a DC signal from the photoplethysmography signal; obtaining a DC characteristic from the DC signal; determining a reference DC characteristic; and, based on a set step size, applying pressure to or reducing the pressure outside the blood vessel to make the current DC characteristic equal to the reference DC characteristic value, thereby completing measurement compensation. The present invention discloses a method, device, and apparatus for compensating for blood pressure measurement with rapid changes in blood pressure, capable of applying pressure to or reducing the pressure outside the blood vessel when the blood pressure in the measured blood vessel changes rapidly, thereby compensating for the blood pressure measurement and improving the accuracy and tracking capability of the blood pressure measurement.

Description

Technical Field

[0001] The present invention belongs to the field of blood pressure measurement, and in particular relates to a blood pressure measurement compensation method, device and equipment for rapid blood pressure changes. Background Art

[0002] Although the traditional photoplethysmography (PPG) blood pressure detection method has the advantages of good portability and fast measurement speed, it often has difficulty providing stable blood pressure measurement and tracking capabilities when the measured blood pressure changes rapidly, resulting in poor blood pressure tracking and inaccurate measurement results. Summary of the Invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and proposes a blood pressure measurement compensation method, device and equipment for rapid blood pressure changes.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] In a first aspect, the present invention discloses a blood pressure measurement compensation method for rapid blood pressure changes, comprising:

[0006] Acquire a photoplethysmography signal obtained by measuring blood pressure;

[0007] Extracting DC signal from photoplethysmography signal;

[0008] Obtaining a DC feature in the DC signal, wherein the DC feature is an amplitude of the DC signal;

[0009] Determining a reference DC characteristic, wherein the reference DC characteristic is a DC characteristic corresponding to a moment when the photoplethysmography signal has a maximum amplitude;

[0010] According to the set step size, pressure is added or reduced outside the blood vessel to make the current DC characteristic equal to the reference DC characteristic value, completing the measurement compensation.

[0011] In one embodiment of the present invention, the method further comprises:

[0012] Extracting AC signals from photoplethysmography signals;

[0013] Acquiring an AC feature from the AC signal, wherein the average amplitude of the photoplethysmography signal in one cardiac cycle is divided by the difference between the maximum amplitude and the minimum amplitude of the AC signal at a time corresponding to the cardiac cycle, and the result is used as the AC feature of the AC signal at a time corresponding to the cardiac cycle;

[0014] Determining a reference AC signal characteristic, wherein the reference AC signal characteristic is an AC characteristic corresponding to a moment when the photoplethysmography signal has a maximum amplitude;

[0015] After increasing or decreasing pressure outside the blood vessel so that the current DC characteristic is equal to the reference DC characteristic, increasing or decreasing pressure outside the blood vessel is continued so that the current AC signal characteristic is equal to the reference AC signal characteristic.

[0016] In one embodiment of the present invention, the measurement compensation is completed by applying pressure to the outside of the blood vessel according to a set step size to make the current DC characteristic equal to the reference DC characteristic value, including:

[0017] Obtaining a historical direct current characteristic-time curve of the blood vessel whose blood pressure is being measured and a synchronously corresponding historical blood vessel external pressure-time curve;

[0018] Determining a reference time, wherein the reference time is a time corresponding to when the transmural pressure of the blood vessel is zero;

[0019] Based on the historical direct current characteristic-time curve and the historical vascular external pressure-time curve, the historical values ​​corresponding to the time near the reference time are determined respectively, and the direct current characteristic-time function and the vascular external pressure-time function are obtained respectively by using the least squares method;

[0020] Based on the DC characteristic-time function and the vascular external pressure-time function, a vascular external pressure-DC characteristic function is established;

[0021] According to the blood vessel external pressure-DC characteristic function, the blood vessel external pressure corresponding to the current DC characteristic is determined to be a set step size.

[0022] In one embodiment of the present invention, extracting a DC signal from a photoplethysmography signal includes filtering the photoplethysmography signal using a low-pass filter to obtain a DC signal.

[0023] In one embodiment of the present invention, extracting the AC signal from the photoplethysmography signal includes: sequentially processing the photoplethysmography signal through a high-pass filter and a low-pass filter to obtain the AC signal.

[0024] In one embodiment of the present invention, based on the external blood vessel pressure-DC characteristic function, determining that the external blood vessel pressure corresponding to the current DC characteristic is a set step size includes: based on the external blood vessel pressure-DC characteristic function, obtaining the external blood vessel pressure change-DC characteristic change function; the external blood vessel pressure change corresponding to the current DC characteristic change is the set step size.

[0025] In one embodiment of the present invention, historical values ​​corresponding to moments near a reference moment are determined respectively, and the DC characteristic-time function and the vascular external pressure-time function are obtained respectively using the least squares method, including: selecting the historical values ​​corresponding to the reference moment and the two adjacent moments before and after the reference moment on the historical DC characteristic-time curve and the historical vascular external pressure-time curve respectively, and obtaining the DC characteristic-time function and the vascular external pressure-time function respectively based on the three historical values ​​corresponding to each curve using the least squares method.

[0026] In a second aspect, the present invention discloses a blood pressure measurement compensation device for rapid blood pressure changes, the device comprising:

[0027] A first acquisition module is used to acquire a photoplethysmography signal obtained by measuring blood pressure;

[0028] An extraction module, used for extracting a DC signal from a photoplethysmography signal;

[0029] a second acquisition module, configured to acquire a DC feature in the DC signal, wherein the DC feature is an amplitude of the DC signal;

[0030] a determination module, configured to determine a reference DC characteristic, wherein the reference DC characteristic is a DC characteristic corresponding to a moment when the amplitude of the photoplethysmography signal is maximum;

[0031] The compensation module is used to increase or decrease the pressure outside the blood vessel according to the set step size to make the current DC characteristic equal to the reference DC characteristic value, thereby completing the measurement compensation.

[0032] In a third aspect, the present invention discloses an electronic device comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors execute the above method.

[0033] In a fourth aspect, the present invention discloses a computer program product, comprising a computer program, which implements the above method when executed by a processor.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] The present invention discloses a method, device, and apparatus for compensating for blood pressure measurement with rapid changes in blood pressure, comprising: obtaining a photoplethysmography signal obtained by measuring blood pressure; extracting a DC signal from the photoplethysmography signal; obtaining a DC characteristic from the DC signal; determining a reference DC characteristic; and, based on a set step size, applying pressure and decompression externally to a blood vessel to make the current DC characteristic equal to the reference DC characteristic value, thereby completing measurement compensation. The present invention discloses a method, device, and apparatus for compensating for blood pressure measurement with rapid changes in blood pressure, capable of performing external pressure and decompression compensation on a measured blood vessel when the blood pressure in the vessel changes rapidly, thereby improving the tracking capability of the blood pressure measurement and achieving a more accurate blood pressure measurement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0037] In the attached figure:

[0038] Figure 1 A schematic diagram of a blood pressure measurement compensation method for rapid blood pressure changes according to an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of extracting a DC signal from a blood pressure measurement compensation method for rapid blood pressure changes according to an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of extracting AC signals from a blood pressure measurement compensation method for rapid blood pressure changes according to an embodiment of the present invention;

[0041] Figure 4 Schematic diagram of a historical direct current characteristic-time curve and a historical blood vessel external pressure-time curve according to an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of a blood pressure measurement and compensation device for rapid blood pressure changes according to an embodiment of the present invention;

[0043] Figure 6 Schematic diagram of an electronic device for measuring and compensating for rapid blood pressure changes according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0046] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0047] In the description of the present invention, it should be further clarified that the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0048] Although the traditional photoplethysmography (PPG) blood pressure detection method has the advantages of good portability and fast measurement speed, it often has difficulty providing stable blood pressure measurement and tracking capabilities when the measured blood pressure changes rapidly, resulting in poor blood pressure tracking and inaccurate measurement results.

[0049] The present invention discloses a blood pressure measurement compensation method, device and equipment for rapidly changing blood pressure. By obtaining the DC characteristics in the photoplethysmography signal and determining the reference DC characteristics, the pressure is increased or decreased outside the blood vessel. When the blood pressure in the measured blood vessel changes rapidly, the blood pressure measurement can be compensated, and more accurate blood pressure measurement results can be obtained, thereby improving the tracking capability of the measured blood pressure.

[0050] This method compensates for blood pressure measurement by controlling the airbag to increase or decrease pressure outside the measured blood vessel. During normal blood pressure measurement, the airbag is wrapped around the outside of the measured blood vessel and applies initial pressure to the blood vessel. When the blood pressure in the blood vessel drops rapidly, the airbag can automatically and instantly reduce the external pressure applied to the blood vessel to achieve blood pressure measurement compensation, ensuring that the transmural pressure of the blood vessel is zero and the blood vessel is in a stress-free and standard reference volume state. This ensures the accuracy of measuring blood pressure in the blood vessel using the blood pressure measurement method based on photoplethysmography at this time, and improves the real-time tracking effect of blood pressure measurement.

[0051] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0052] In one embodiment of the present invention, Figure 1 As shown, a blood pressure measurement compensation method for rapid blood pressure changes includes:

[0053] Step S101, obtaining a photoplethysmography signal obtained by measuring blood pressure;

[0054] Step S102, extracting the DC signal from the photoplethysmography signal;

[0055] In this embodiment, if Figure 2 As shown, the photoplethysmography signal is filtered using a low-pass filter to obtain a DC signal.

[0056] Exemplarily, a 0.5 Hz low-pass filter is used to filter the photoplethysmography signal to obtain a DC signal. In one possible implementation, the low-pass filter coefficients b and a are generated using the butter function in the MATLAB signal processing toolbox for designing a Butterworth low-pass filter, where the filter order is 3, the cutoff frequency fc is 0.5 Hz, and the sampling frequency fs is 250 Hz. Furthermore, the photoplethysmography signal is low-pass filtered using the filter function to retain the DC component and remove high-frequency interference to obtain a DC signal, specifically expressed as filter(b, a, x), where b and a represent the filter coefficients, and x represents the photoplethysmography signal.

[0057] Step S103, obtaining a DC feature in the DC signal, wherein the DC feature is the amplitude of the DC signal;

[0058] Step S104, determining a reference DC characteristic, wherein the reference DC characteristic is the DC characteristic corresponding to the moment when the photoplethysmography signal amplitude is maximum;

[0059] The reference DC characteristic indicates that the transmural pressure of the blood vessel being measured is zero, and the vessel is in a stress-free and standard reference volume state. At this time, the blood pressure measurement method based on photoplethysmography can measure the blood pressure in the blood vessel with satisfactory accuracy. Existing blood pressure measurement methods based on photoplethysmography are inaccurate when blood pressure changes rapidly because the volume inside the blood vessel changes and cannot be compensated.

[0060] In step S105, the pressure outside the blood vessel is increased or decreased according to the set step size to make the current DC characteristic equal to the reference DC characteristic value, thereby completing the measurement compensation.

[0061] This embodiment utilizes the DC characteristics in the photoplethysmography signal and determines the reference DC characteristics to control the pressure increase or decrease of the airbag outside the blood vessel. This can compensate for the blood pressure measurement when the blood pressure in the measured blood vessel changes rapidly, achieve more accurate blood pressure measurement results, and improve the tracking ability of the measured blood pressure.

[0062] Based on the previous embodiment, in another embodiment of the present invention, the method further includes:

[0063] Extracting AC signals from photoplethysmography signals;

[0064] In this embodiment, if Figure 3 As shown in FIG, the photoplethysmography signal is processed by a high-pass filter and a low-pass filter in sequence to obtain an AC signal.

[0065] For example, in one possible implementation, the high-pass filter coefficients b and a are generated using the butter function for designing a Butterworth high-pass filter in the MATLAB signal processing toolbox, where the filter order is 3, the cutoff frequency fc is 0.5 Hz, and the sampling frequency fs is 250 Hz. Furthermore, the photoplethysmography signal is high-pass filtered using the filter function to retain the high-pass component, and then low-pass filtered using a low-pass filter, where the cutoff frequency of the low-pass filter is 50 Hz and the sampling frequency is 250 Hz, to ultimately obtain an AC signal.

[0066] Acquiring an AC feature from the AC signal, wherein the average amplitude of the photoplethysmography signal in one cardiac cycle is divided by the difference between the maximum amplitude and the minimum amplitude of the AC signal at a time corresponding to the cardiac cycle, and the result is used as the AC feature of the AC signal at a time corresponding to the cardiac cycle;

[0067] For example, the average amplitude is expressed as , there is the following relationship:

[0068] ;

[0069] in,T Represents the cardiac cycle, It is represented as a segment of the photoplethysmography signal corresponding to a cardiac cycle, where the cardiac cycle is determined by detecting the time between two consecutive troughs in the acquired photoplethysmography signal;

[0070] The AC characteristics are expressed as Prop, There are the following relationships:

[0071] ;

[0072] in, is the maximum amplitude of the AC signal segment corresponding to the cardiac cycle, It is the minimum amplitude of the AC signal segment corresponding to the cardiac cycle;

[0073] For example, when the cardiac cycle T=0.8s, the AC signal segment amplitude is as follows:

[0074] （70.0, 71.0, 72.0, 73.0, 74.0, 75.0, 76.0, 77.0, 78.0, 78.9, 79.9,80.9, 81.9, 82.8, 83.8, 84.7, 85.6, 86.5, 87.4, 88.3, 89.2, 90.0, 90.9, 91.7,92.5, 93.3, 94.0, 94.8, 95.5, 96.2, 96.9, 97.6, 98.2, 98.8, 99.4, 100.0,100.5, 101.0, 101.5, 102.0, 102.4, 102.8, 103.2, 103.6, 103.9, 104.2, 104.5,104.8, 105.0, 105.2, 105.4, 105.5, 105.6, 105.7, 105.8, 105.8, 105.8, 105.8,105.8, 105.7, 105.6, 105.5, 105.4, 105.2, 105.0, 104.8, 104.5, 104.2, 103.9,103.6, 103.2, 102.8, 102.4, 102.0, 101.5, 101.0, 100.5, 100.0, 99.4, 98.8,98.2, 97.6, 96.9, 96.2, 95.5, 94.8, 94.0, 93.3, 92.5, 91.7, 90.9, 90.0, 89.2,88.3, 87.4, 86.5, 85.6, 84.7, 83.8, 82.8, 81.9, 80.9, 79.9, 78.9, 78.0, 77.0,76.0, 75.0, 74.0, 73.0, 72.0, 71.0, 70.0, 69.0, 68.0, 67.0, 66.0, 65.1, 64.1,63.1, 62.1, 61.2, 60.2, 59.3, 58.4, 57.5, 56.6, 55.7, 54.9, 54.1, 53.3, 52.5,51.7, 51.0, 50.2, 49.5, 48.8, 48.1, 47.4, 46.8, 46.2, 45.6, 45.0, 44.5, 44.0,43.5, 43.0, 42.6, 42.2, 41.8, 41.4, 41.1, 40.8, 40.5, 40.2, 40.0, 39.8, 39.6,39.5, 39.4, 39.3, 39.2, 39.2, 39.2, 39.2, 39.2, 39.3, 39.4, 39.5, 39.6, 39.8,40.0, 40.2, 40.5, 40.8, 41.1, 41.4, 41.8, 42.2, 42.6, 43.0, 43.5, 44.0, 44.5,45.0, 45.6, 46.2, 46.8, 47.4, 48.1, 48.8, 49.5, 50.2, 51.0, 51.7, 52.5, 53.3,54.1, 54.9, 55.7, 56.6, 57.5, 58.4, 59.3, 60.2, 61.2, 62.1, 63.1, 64.1, 65.1,66.0, 67.0, 68.0, 69.0);.

[0075] Here are the results:

[0076] =46.87;

[0077] =105.8, =39.2;

[0078] =46.87 / (105.8-39.2) ≈ 0.7.

[0079] Determining a reference AC signal characteristic, wherein the reference AC signal characteristic is an AC characteristic corresponding to a moment when the photoplethysmography signal has a maximum amplitude;

[0080] After increasing or decreasing pressure outside the blood vessel so that the current DC characteristic is equal to the reference DC characteristic, increasing or decreasing pressure outside the blood vessel is continued so that the current AC signal characteristic is equal to the reference AC signal characteristic.

[0081] In this embodiment, based on the comparison between the current AC signal characteristics and the reference AC signal characteristics, the airbag is regulated by a PID control algorithm to pressurize the measured blood vessel.

[0082] Here is an example:

[0083] ;

[0084] in, Indicates the amount of adjustment required to continue increasing or decreasing the pressure outside the blood vessel after the current DC characteristic is equal to the reference DC characteristic; Indicates the current AC signal characteristics; represents the proportionality coefficient, represents the integral coefficient, represents the differential coefficients, all determined empirically; Indicates the signal sampling point index.

[0085] Exemplary:

[0086] PID parameters are adjusted to: kp=5, ki=1, kd=2;

[0087] The last three sampling values:

[0088] prop(k-2)=0.78, prop(k-1)=0.7, prop(k)=0.68;

[0089] The proportional term is (0.68-0.7)×5 = -0.1;

[0090] The integral term is 0.68 × 1 = 0.68;

[0091] The differential term is (0.78-2×0.7+0.78)×2 =0.32;

[0092] Adjustment amount =0.1 + 0.68 +0.32 = 0.9 mmHg, where negative values ​​indicate decompression and positive values ​​indicate compression;

[0093] This embodiment utilizes the AC signal characteristics to continue to increase and decrease the pressure outside the blood vessel, thereby achieving more precise blood pressure measurement compensation and improving the real-time and accuracy of blood pressure measurement.

[0094] For example, a dual-loop PID control can be used to adjust the airbag pressure. The outer loop quickly adjusts the pressure to compensate for rapid changes in blood pressure, and the inner loop performs fine pressure regulation to track subtle fluctuations in blood pressure, ultimately achieving accurate blood pressure measurement.

[0095] Based on the previous embodiment, in another embodiment of the present invention, according to a set step size, pressure is added or reduced outside the blood vessel to make the current DC characteristic equal to the reference DC characteristic value, thereby completing measurement compensation, including:

[0096] Obtaining a historical direct current characteristic-time curve of the blood vessel whose blood pressure is being measured and a synchronously corresponding historical blood vessel external pressure-time curve;

[0097] Determining a reference time, wherein the reference time is a time corresponding to when the transmural pressure of the blood vessel is zero;

[0098] When the transmural pressure of the blood vessel is zero, that is, the blood vessel is in a stress-free and standard reference volume state. At this time, the reference volume of the blood vessel is represented by V0. For example, when looking for the systolic and diastolic pressure of the finger, the pressure is first increased and then released. During the pressure release process, the oscillation amplitude of the photoelectric volume pulse wave signal will change with the change of the transmural pressure of the blood vessel. When the blood vessel is in a stress-free state (that is, when the transmural pressure of the blood vessel is 0), the oscillation amplitude of the photoelectric volume pulse wave signal reaches the maximum value. At this time, the blood vessel volume is the reference volume V0. The external blood vessel pressure P0, DC characteristics and AC characteristics corresponding to the finger whose blood pressure is measured at this time are obtained, wherein the DC characteristics are used as reference DC characteristics, and the AC characteristics are used as reference AC characteristics.

[0099] Based on the historical direct current characteristic-time curve and the historical vascular external pressure-time curve, the historical values ​​corresponding to the time near the reference time are determined respectively, and the direct current characteristic-time function and the vascular external pressure-time function are obtained respectively by using the least squares method;

[0100] Based on the DC characteristic-time function and the vascular external pressure-time function, a vascular external pressure-DC characteristic function is established;

[0101] According to the blood vessel external pressure-DC characteristic function, the blood vessel external pressure corresponding to the current DC characteristic is determined to be a set step size.

[0102] In the above embodiment, in another embodiment of the present invention, historical values ​​corresponding to times near the reference time are determined respectively, and the DC characteristic-time function and the vascular external pressure-time function are obtained respectively by using the least square method, including: Figure 4 As shown, on the historical DC characteristic-time curve and the historical vascular external pressure-time curve, the historical values ​​corresponding to the reference moment and the two adjacent moments before and after the reference moment are selected, and based on the three historical values ​​corresponding to each curve, the DC characteristic-time function and the vascular external pressure-time function are obtained respectively using the least squares method.

[0103] like Figure 4 As shown, three points are taken on the historical DC characteristic-time curve and the historical vascular external pressure-time curve, which are the reference moment when the vascular volume is the reference volume V0, and two moments equidistant on both sides of the reference moment. Three historical values ​​are obtained, and a linear fit is established using the least squares method to obtain the DC characteristic-time function and the vascular external pressure-time function, respectively. The examples are as follows:

[0104] Based on the historical DC characteristic-time curve, the three points are expressed as: PPG DC0 (t0,PPG DC0 ), PPG DC1 (t1,PPG DC1) and PPG DC2 (t2,PPG DC2 );

[0105] Fit using the least squares method:

[0106] S x =t0+t1+t2;

[0107] S y =PPG DC0 +PPG DC1 +PPG DC2 ;

[0108] S xx = t0 2 +t1 2 + t2 2 ;

[0109] S xy =t0PPG DC0 +t1PPG DC1 +t2PPG DC2 ;

[0110] Further, calculate the slope m1 and intercept c1:

[0111] ;

[0112] ;

[0113] Get the DC characteristic-time function, expressed as PPG DC :

[0114] PPG DC =m1t+c1;

[0115] Similarly, based on the historical vascular external pressure-time curve, three points are taken as: P0 (t0, P0), P1 (t1, P1), and P2 (t2, P2);

[0116] Fit using the least squares method:

[0117] S x =t0+t1+t2;

[0118] S y =P0+P1+P2;

[0119] S xx = t0 2 +t1 2 + t2 2 ;

[0120] S xy=t0P0+t1P1+t2P2;

[0121] Further, calculate the slope m2 and intercept c2:

[0122] ;

[0123] ;

[0124] The external blood vessel pressure-time function is obtained, expressed as P:

[0125] P=m2t+c2;

[0126] Based on PPG DC =m1t+c1 and P=m2t+c2, the vascular external pressure-DC characteristic function is established as follows:

[0127] ;

[0128] Furthermore, the above formula can be converted to P=a×PPG DC +b, where a is the calibration coefficient and b is the constant term;

[0129] In the previous embodiment, in another embodiment of the present invention, the external blood vessel pressure corresponding to the current DC characteristic is determined to be a set step size based on the external blood vessel pressure-DC characteristic function, including: obtaining the external blood vessel pressure change-DC characteristic change function based on the external blood vessel pressure-DC characteristic function; the external blood vessel pressure change corresponding to the current DC characteristic change is the set step size.

[0130] For example, based on P=a×PPG DC + b, we can get:

[0131] ;

[0132] in, is the change in the external pressure of the blood vessel, i.e., the set step size;

[0133] It is the DC characteristic variation that can be calculated;

[0134] a is the calibration factor;

[0135] Exemplary:

[0136] Based on the historical DC characteristic-time curve, the PPG of three points near the reference time t0=15s DC0 (14,260,000), PPG DC1 (15,250,000) and PPG DC2 (16,240000);

[0137] Fit using the least squares method:

[0138] S x = 14 + 15 + 16 = 45;

[0139] S y = 260,000 + 250,000 + 240,000 = 750,000;

[0140] S xx = 14²+15²+16² = 677;

[0141] S xy = 14×260000+ 15×250000+ 16×240000=11230000;

[0142] m1= (3×11230000-45×750000) / (3×677 - 45²) = -10000;

[0143] c1= [750000- (-10000)×45] / 3 =400000;

[0144] Get the DC characteristic-time function, expressed as: PPG DC =-10000t+400000;

[0145] For the historical vascular external pressure-time curve, three points P0 (14,120), P1 (15,115), and P2 (16,110) near the reference time t0=2s;

[0146] Fit using the least squares method:

[0147] S x = 14+15+16 = 45;

[0148] S y = 120+115+110 = 345;

[0149] S xx = 14²+15²+16² = 677;

[0150] S xy = 14×120 + 15×115 + 16 ×110 = 5165;

[0151] m2= (3×5165- 45×345) / (3×677- 45²) = -5;

[0152] c2= (345 - (-5)×45) / 3 = 125;

[0153] The external blood vessel pressure-time function is obtained: P = -5t + 190;

[0154] The external blood vessel pressure-DC characteristic function is as follows:

[0155] P=0.0005PPG DC -10, where a=0.0005 and b=-10.

[0156] In this embodiment, the step size is set to determine the change in external vascular pressure corresponding to the current DC characteristic change. Since it is based on the historical DC characteristic-time curve and the historical external vascular pressure-time curve, the individual adaptability of blood pressure measurement compensation can be effectively improved, for example, it is suitable for a certain type of people, thereby improving the accuracy of blood pressure measurement compensation.

[0157] For example, five healthy subjects (aged 25-40 years) were selected, and after recording baseline blood pressure at rest, systolic and diastolic blood pressure were collected using an Omron sphygmomanometer as a standard control. The patented method was used to dynamically compensate the traditional photoplethysmography blood pressure test results (uncompensated measurement values), and the systolic and diastolic pressures collected before and after compensation were recorded.

[0158] Personnel serial number Omron systolic blood pressure (mmHg) Uncompensated measurement value (mmHg) Compensated measurement value (mmHg) Omron diastolic blood pressure (mmHg) Uncompensated measurement value (mmHg) Compensated measurement value (mmHg) 1 120 118（-2） 119（-1） 80 76（-4） 77（-3） 2 125 130 (+5) 123 (-2) 82 85 (+3) 83 (+1) 3 98 105 (+7) 96 (-2) 65 72 (+7) 63 (-2) 4 105 115 (+10) 107 (+2) 70 76 (+6) 72 (+2) 5 118 125 (+7) 119 (+1) 78 83 (+5) 80 (+2)

[0159] The values ​​in brackets are the deviations from the Omron blood pressure monitor.

[0160] like Figure 5 As shown, the present invention also discloses a blood pressure measurement compensation device for rapid changes in blood pressure, comprising a first acquisition module 501 for acquiring a photoplethysmography signal obtained by measuring blood pressure;

[0161] Extraction module 502, used to extract the DC signal from the photoplethysmography signal;

[0162] A second acquisition module 503 is configured to acquire a DC feature in the DC signal, wherein the DC feature is the amplitude of the DC signal;

[0163] A determination module 504 is configured to determine a reference DC characteristic, wherein the reference DC characteristic is a DC characteristic corresponding to a moment when the photoplethysmography signal has a maximum amplitude;

[0164] The compensation module 505 is used to increase or decrease the pressure outside the blood vessel according to the set step size to make the current DC characteristic equal to the reference DC characteristic value, thereby completing measurement compensation.

[0165] The present invention also discloses an electronic device, such as Figure 6As shown, an embodiment is disclosed, which is a block diagram of an electronic device suitable for compensating for blood pressure measurement with rapid changes in blood pressure.

[0166] The electronic device 60 of this embodiment includes a processor 601, which can perform various appropriate actions and processes according to the program stored in the ROM 602 or the program loaded from the storage part 608 into the RAM 603. The processor 601 may include, for example, a general-purpose microprocessor, an instruction set processor and / or a related chipset and / or a dedicated microprocessor, etc. The processor 601 may also include onboard memory for caching purposes. The processor 601 may include a single processing unit or multiple processing units for performing different actions of the method flow according to the embodiment of the present invention.

[0167] The RAM 603 stores various programs and data required for the operation of the electronic device 60. The processor 601, ROM 602, and RAM 603 are connected to each other via a bus 604. The processor 601 executes the programs in the ROM 602 and / or RAM 603 to perform various operations according to the method flow of the embodiment of the present invention. It should be noted that the programs may also be stored in one or more memories other than the ROM 602 and RAM 603, and the processor 601 may also execute the programs stored in one or more memories to perform various operations according to the method flow of the embodiment of the present invention.

[0168] According to an embodiment of the present invention, the electronic device 60 may further include an I / O interface 605, which is also connected to the bus 604. The electronic device 60 may further include one or more of the following components connected to the I / O interface 605: an input unit 606 including a keyboard, a mouse, etc.; an output unit 607 including a cathode ray tube, a liquid crystal display, and a speaker; a storage unit 608 including a hard disk; and a communication unit 609 including a network interface card such as a LAN card or a modem. The communication unit 609 performs communication processing via a network such as the Internet. A drive 6010 is also connected to the I / O interface 605 as needed. Removable media 6011, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed in the drive 6010 as needed, so that computer programs read therefrom can be installed into the storage unit 608 as needed.

[0169] The present invention also provides a computer-readable storage medium.

[0170] The computer-readable storage medium may be included in the electronic device / device system described in the above embodiments, or may exist independently and not be incorporated into the electronic device / device. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of the present invention.

[0171] According to embodiments of the present invention, a computer-readable storage medium may be a non-volatile computer-readable storage medium. Examples include, but are not limited to, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0172] Embodiments of the present invention also include a computer program product.

[0173] The computer program product includes a computer program, which contains program code for executing the method provided by the embodiment of the present invention. When the computer program product runs on an electronic device, the program code is used to enable the electronic device to implement the method provided by the embodiment of the present invention.

[0174] In one embodiment, the computer program may be stored on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may be transmitted and distributed in the form of a signal over a network medium. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0175] According to an embodiment of the present invention, the program code for executing the computer program provided by the embodiment of the present invention can be written by any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level procedural and / or object-oriented programming languages. Programming languages ​​include, but are not limited to, Java, C++, Python, C language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network or a wide area network, or can be connected to an external computing device.

[0176] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the boxes may occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, as well as the combination of boxes in the block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or may be implemented using a combination of dedicated hardware and computer instructions. It will be understood by those skilled in the art that the features described in the various embodiments and / or claims of the present invention may be combined and / or coupled in various ways, even if such combinations or couplings are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments and / or claims of the present invention may be combined and / or coupled in various ways, and all such combinations and / or couplings fall within the scope of the present invention.

[0177] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although each embodiment has been described above separately, this does not mean that the measures in each embodiment cannot be advantageously used in combination. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A blood pressure measurement compensation method for rapid blood pressure changes, characterized in that: The method comprises: Acquire a photoplethysmography signal obtained by measuring blood pressure; extracting a DC signal from the photoplethysmography signal; Acquire a DC characteristic in the DC signal, wherein the DC characteristic is the amplitude of the DC signal; Determining a reference DC characteristic, wherein the reference DC characteristic is the DC characteristic corresponding to the moment when the amplitude of the photoplethysmography signal is maximum; According to the set step size, increasing or decreasing the pressure outside the blood vessel so that the current DC characteristic is equal to the reference DC characteristic value, thereby completing measurement compensation; extracting an AC signal from the photoplethysmography signal; Acquiring an AC feature in the AC signal, wherein an average amplitude of the photoplethysmography signal in one cardiac cycle is divided by a difference between a maximum amplitude and a minimum amplitude of the AC signal at a time corresponding to the cardiac cycle, and the result is used as the AC feature of the AC signal at a time corresponding to the cardiac cycle; Determining a reference AC signal characteristic, wherein the reference AC signal characteristic is the AC characteristic corresponding to the moment when the photoplethysmography signal has a maximum amplitude; After increasing or decreasing pressure outside the blood vessel so that the current DC characteristic is equal to the reference DC characteristic, increasing or decreasing pressure outside the blood vessel so that the current AC signal characteristic is equal to the reference AC signal characteristic; The step of increasing or decreasing the pressure outside the blood vessel according to the set step size so that the current DC characteristic is equal to the reference DC characteristic value to complete the measurement compensation includes: Obtaining a historical direct current characteristic-time curve of the blood vessel whose blood pressure is being measured and a synchronously corresponding historical blood vessel external pressure-time curve; Determining a reference time, wherein the reference time is a time corresponding to when the transmural pressure of the blood vessel is zero; Based on the historical direct current characteristic-time curve and the historical external blood vessel pressure-time curve, respectively determining historical values ​​corresponding to times near the reference time, and using the least squares method to obtain the direct current characteristic-time function and the external blood vessel pressure-time function; Establishing an external blood vessel pressure-direct current characteristic function based on the direct current characteristic-time function and the external blood vessel pressure-time function; According to the blood vessel external pressure-direct current characteristic function, it is determined that the blood vessel external pressure corresponding to the current direct current characteristic is the set step size.

2. A blood pressure measurement compensation method for rapid blood pressure changes according to claim 1, characterized in that: The extracting of the DC signal from the photoplethysmography signal includes: filtering the photoplethysmography signal with a low-pass filter to obtain the DC signal.

3. A blood pressure measurement compensation method for rapid blood pressure changes according to claim 1, characterized in that: The extracting of the AC signal from the photoplethysmography signal includes: sequentially processing the photoplethysmography signal through a high-pass filter and a low-pass filter to obtain the AC signal.

4. A blood pressure measurement compensation method for rapid blood pressure changes according to claim 1, characterized in that: The method of determining, based on the external blood vessel pressure-DC characteristic function, that the external blood vessel pressure corresponding to the current DC characteristic is the set step size includes: obtaining an external blood vessel pressure change-DC characteristic change function based on the external blood vessel pressure-DC characteristic function; and the external blood vessel pressure change corresponding to the current DC characteristic change is the set step size.

5. The blood pressure measurement compensation method for rapid blood pressure changes according to claim 1, characterized in that: The method of respectively determining the historical values ​​corresponding to the moments near the reference moment and using the least squares method to respectively obtain the DC characteristic-time function and the external vascular pressure-time function includes: respectively selecting the historical values ​​corresponding to the reference moment and the two adjacent moments before and after the reference moment on the historical DC characteristic-time curve and the historical external vascular pressure-time curve, and based on the three historical values ​​corresponding to each curve, using the least squares method to respectively obtain the DC characteristic-time function and the external vascular pressure-time function.

6. A blood pressure measurement and compensation device for rapid blood pressure changes, characterized by: The device comprises: A first acquisition module is used to acquire a photoplethysmography signal obtained by measuring blood pressure; A first extraction module is used to extract a DC signal from the photoplethysmography signal; a second extraction module, configured to extract an AC signal from the photoplethysmography signal; a second acquisition module, configured to acquire a DC characteristic in the DC signal, wherein the DC characteristic is an amplitude of the DC signal; a third acquisition module, configured to acquire an AC feature in the AC signal, wherein the average amplitude of the photoplethysmography signal in one cardiac cycle is divided by the difference between the maximum amplitude and the minimum amplitude of the AC signal at a time corresponding to the cardiac cycle, as the AC feature of the AC signal at a time corresponding to the cardiac cycle; a first determining module, configured to determine a reference DC characteristic, wherein the reference DC characteristic is the DC characteristic corresponding to the moment when the amplitude of the photoplethysmography signal is maximum; a second determining module, determining a reference AC signal characteristic, wherein the reference AC signal characteristic is the AC characteristic corresponding to the moment when the photoplethysmography signal has the maximum amplitude; a compensation module, configured to apply pressure to the outside of the blood vessel according to a set step size to make the current DC characteristic equal to the reference DC characteristic value, thereby completing measurement compensation, including: obtaining a historical DC characteristic-time curve of the blood vessel whose blood pressure is being measured and a synchronously corresponding historical pressure-time curve outside the blood vessel; Determining a reference time, wherein the reference time is a time corresponding to when the transmural pressure of the blood vessel is zero; Based on the historical direct current characteristic-time curve and the historical external blood vessel pressure-time curve, respectively determining historical values ​​corresponding to times near the reference time, and using the least squares method to obtain the direct current characteristic-time function and the external blood vessel pressure-time function; Establishing an external blood vessel pressure-direct current characteristic function based on the direct current characteristic-time function and the external blood vessel pressure-time function; determining, based on the external blood vessel pressure-direct current characteristic function, that the external blood vessel pressure corresponding to the current direct current characteristic is the set step size; After increasing or decreasing pressure outside the blood vessel so that the current DC characteristic is equal to the reference DC characteristic, increasing or decreasing pressure outside the blood vessel is continued so that the current AC signal characteristic is equal to the reference AC signal characteristic.

7. An electronic device, characterized in that: include: one or more processors; A storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors are caused to perform the method according to any one of claims 1 to 5.

8. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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