Method, system and electronic device for determining a blood pressure signal envelope

Abstract

The present application provides a kind of blood pressure signal envelope determination method, system and electronic equipment, comprising: obtaining the blood pressure signal and photoelectric volume signal of target object synchronously collected;Extract the effective blood pressure signal section in blood pressure signal, and calculate the periodic heart rate in effective blood pressure signal section;Wherein, effective blood pressure signal section is the blood pressure signal with peak point or valley point and periodicity;Based on all periodic heart rates, determine effective photoelectric volume signal section;Wherein, effective photoelectric volume signal section is the photoelectric volume signal that is aligned with effective blood pressure signal section by heart rate;Determine the pressure value corresponding to effective blood pressure signal section, based on effective blood pressure signal section, effective photoelectric volume signal section and pressure value, determine the blood pressure signal envelope of target object. By taking blood pressure signal as benchmark, the method of aligning photoelectric volume signal cycle with blood pressure signal cycle is used to improve the accuracy of blood pressure signal envelope extraction, and then the accuracy of blood pressure measurement is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a blood pressure signal envelope determination method, system and electronic device. BACKGROUND

[0002] The existing blood pressure measurement method is generally measured by the amplitude change envelope of the pressure oscillation wave in the process of pressure increasing or decreasing. Specifically, when extracting the envelope, the difference between the peak and the trough is usually taken as the vertical coordinate, and the pressure value corresponding to the maximum slope point, peak point or trough point between the peak and the trough is taken as the horizontal coordinate. Due to the existence of body movement, muscle contraction induced motion, sensor introduced white noise and respiratory interference and other situations in the measurement process, some abnormal values will appear in the extracted envelope, which reduces the accuracy of blood pressure envelope extraction, and further reduces the accuracy of blood pressure measurement. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a blood pressure signal envelope determination method, system and electronic device to improve the accuracy of blood pressure signal envelope extraction, and further improve the accuracy of blood pressure measurement.

[0004] In a first aspect, an embodiment of the present application provides a blood pressure signal envelope determination method, comprising: acquiring a blood pressure signal and a photoplethysmography signal of a target object collected synchronously; extracting an effective blood pressure signal segment in the blood pressure signal, and calculating a periodic heart rate in the effective blood pressure signal segment; wherein the effective blood pressure signal segment is a blood pressure signal with a peak point or a trough point and periodicity; determining an effective photoplethysmography signal segment based on all periodic heart rates; wherein the effective photoplethysmography signal segment is a photoplethysmography signal aligned with the effective blood pressure signal segment through the heart rate; determining a pressure value corresponding to the effective blood pressure signal segment, and determining a blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective photoplethysmography signal segment and the pressure value.

[0005] Further, after the step of determining the blood pressure signal envelope, the method further comprises: judging whether the blood pressure signal envelope contains abnormal values based on the photoplethysmography signal; if the blood pressure signal envelope contains abnormal values, removing the abnormal values; interpolating the blood pressure signal envelope after removing the abnormal values; performing smoothing processing on the interpolated blood pressure signal envelope to obtain a target blood pressure signal envelope; and calculating a blood pressure value of the target object based on the target blood pressure signal envelope.

[0006] Further, the steps of extracting the effective blood pressure signal segment from the blood pressure signal and calculating the periodic heart rate in the effective blood pressure signal segment include: extracting extreme points from the blood pressure signal based on peak detection; the extreme points are peak points and / or valley points; determining the effective blood pressure signal segment based on the extracted extreme points; determining the sampling time of the extreme points, calculating the time difference between two adjacent extreme points, and determining the time difference as the periodic heart rate.

[0007] Furthermore, the step of determining the effective photoplethysmography (PPG) signal segment based on all heart rate cycles includes: determining the start and end times of the PPG signal segment; calculating the PPG cycle heart rate of the PPG signal segment; determining the PPG signal segment aligned with the effective blood pressure signal segment based on the PPG cycle heart rate and the heart rate cycle; and defining the determined PPG signal segment as the effective PPG signal segment.

[0008] Further, the step of determining the start and end times of the photoplethysmography (PPG) signal segment includes: acquiring the minimum and maximum sampling times within the effective blood pressure signal segment; and determining the start time of the PPG signal segment based on the minimum sampling time, wherein... The end time of the effective photoplethysmography signal segment is determined based on the maximum sampling time, where, The average heart rate is the average of the cyclic heart rate within the effective blood pressure signal segment.

[0009] Further, the step of determining the identified photoplethysmography (PPG) signal segment as the effective PPG signal segment includes: acquiring the PPG periodic heart rate and the periodic heart rate, and calculating the distance between any two points in the PPG periodic heart rate and the periodic heart rate according to the following formula: d(i,j)=||HR_BP i -HR_PPG j || W Where d(i,j) is the distance between any two points in the photoplethysmography periodic heart rate and the periodic heart rate, i = 1, 2, ..., n, j = 1, 2, ..., m, n is the maximum value of i, and m is the maximum value of j; HR_BP i ={HR_BP1,HR_BP2,…,HR_BP n} represents the periodic heart rate set; HR_PPG j ={HR_PPG1,HR_PPG2,…,HR_PPG m} represents the photoplethysmography periodic heart rate set; W is a variable parameter, when W=1, the distance is the Manhattan distance; when W=2, the distance is the Euclidean distance; the distance matrix D is determined based on the distance. Based on matrix D, the optimal regularized path is calculated using the following formula: P best ={P1,P2,…,P k ,…,PK}; where P best For the optimal regularized path; P best ={P1,P2,…,P k ,…,P K} represents HR_BP i With HR_PPG j Alignment; K is the number of paths, max(n,m)≤K≤n+m-1; Calculate the dynamic time warped distance based on the following formula: Among them, DTW(HR_BP) i ,HR_PPG j ) represents the dynamic time warping distance, which makes HR_BP i and HR_PPG j The cumulative distance value is the smallest.

[0010] Furthermore, the step of identifying the determined photoplethysmography (PPG) signal segment as the effective PPG signal segment also includes: determining the minimum cumulative distance and alignment path coordinates between the PPG signal segment and the effective blood pressure signal segment based on the distance between any two points in the PPG cycle heart rate and the dynamic time warping distance; and determining matrix E based on the alignment path coordinates, the cycle heart rate, the PPG cycle heart rate, the start time of the cycle heart rate, and the start time of the PPG cycle heart rate. Where HR_BP_loc represents the aligned coordinates of the effective blood pressure signal segment, and HR_PPG_loc represents the aligned coordinates of the photoplethysmography (PPG) signal segment; HR_BP represents the cyclic heart rate; HR_PPG represents the cyclic heart rate of the PPG; HR_BP_starttime represents the start time of the cyclic heart rate; HR_PPG_starttime represents the start time of the cyclic heart rate of the PPG; and HR_BP in matrix E is calculated. k With HR_PPG k Minimum difference value, retrieve the HR_BP_starttime corresponding to the minimum difference value. k With HR_PPG_starttime k The alignment time difference between the photoplethysmography (PPG) signal segment and the effective blood pressure signal segment is calculated using the following formula: Δt = abs(HR_BP_starttime) k -HR_PPG_starttime k ); where Δt is the alignment time difference; when HR_BP_starttime k >HR_PPG_starttime k At that time, the effective blood pressure signal segment remains unchanged, while the photoplethysmography signal segment shifts to the left by Δt; when HR_BP_starttime k ≤HR_PPG_starttimek At that time, the effective blood pressure signal segment remains unchanged, while the photoplethysmography (PPG) signal segment shifts to the right by Δt; the shifted PPG signal segment is determined to be the effective PPG signal segment.

[0011] Furthermore, the step of determining the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective photoplethysmography signal segment, and the pressure value includes: using the difference between the peak point and the trough point of the effective blood pressure signal segment as the abscissa, and using the pressure value corresponding to the point with the largest upward slope of the effective photoplethysmography signal segment as the abscissa, to determine the blood pressure signal envelope of the target object.

[0012] Secondly, embodiments of the present invention provide a system for determining the blood pressure signal envelope, comprising: a data acquisition module for acquiring blood pressure signals and photoplethysmography (PPG) signals of a target object acquired synchronously; an effective blood pressure signal segment acquisition module for extracting effective blood pressure signal segments from the blood pressure signals and calculating the periodic heart rate within the effective blood pressure signal segments; wherein, the effective blood pressure signal segment is a blood pressure signal with peak or trough points and periodicity; an effective PPG signal segment determination module for determining effective PPG signal segments based on all periodic heart rates; wherein, the effective PPG signal segment is a PPG signal aligned with the effective blood pressure signal segment through heart rate; and a blood pressure signal envelope determination module for determining the pressure value corresponding to the effective blood pressure signal segment and determining the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective PPG signal segment, and the pressure value.

[0013] Thirdly, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program that can run on the processor, and the processor executes the computer program to implement the method described above.

[0014] This invention provides a method, system, and electronic device for determining the blood pressure signal envelope, comprising: acquiring blood pressure signals and photoplethysmography (PPG) signals of a target object simultaneously; extracting effective blood pressure signal segments from the blood pressure signals and calculating the periodic heart rate within the effective blood pressure signal segments; wherein, the effective blood pressure signal segment is a blood pressure signal with peak or trough points and periodicity; determining effective PPG signal segments based on all periodic heart rates; wherein, the effective PPG signal segment is a PPG signal aligned with the effective blood pressure signal segment through heart rate; determining the pressure value corresponding to the effective blood pressure signal segment; and determining the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective PPG signal segment, and the pressure value. In this method, by simultaneously acquiring blood pressure signals and PPG signals, and using the blood pressure signal as a reference to align the PPG signal period with the blood pressure signal period, the accuracy of blood pressure signal envelope extraction is improved, thereby enhancing the accuracy of blood pressure measurement.

[0015] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the method for determining the blood pressure signal envelope provided in Embodiment 1 of the present invention;

[0019] Figure 2 This is a flowchart of determining the effective photoplethysmography signal segment based on all heart rates in Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of signal segmentation provided in Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic diagram of periodic heart rate alignment provided in Embodiment 1 of the present invention;

[0022] Figure 5 This is a schematic diagram of effective photoplethysmography signal segment alignment provided in Embodiment 1 of the present invention;

[0023] Figure 6 This is a schematic diagram of blood pressure signal envelope extraction provided in Embodiment 1 of the present invention;

[0024] Figure 7 This is a flowchart for determining the blood pressure signal envelope of a target object according to Embodiment 1 of the present invention;

[0025] Figure 8 This is a schematic diagram illustrating the calculation of blood pressure values ​​for the target object provided in Embodiment 1 of the present invention;

[0026] Figure 9 This is a schematic diagram of the blood pressure signal envelope determination system provided in Embodiment 2 of the present invention.

[0027] Icons: 1-Data acquisition module; 2-Effective blood pressure signal segment acquisition module; 3-Effective photoplethysmography signal segment determination module; 4-Blood pressure signal envelope determination module. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The oscillometric method, also known as the oscillation method, is a widely used blood pressure measurement technique in various clinical monitors and electronic blood pressure monitors. The oscillometric method determines blood pressure based on the envelope of the pressure oscillation wave amplitude change during cuff inflation or deflation. When extracting the envelope, the difference between the peak and trough is typically used as the ordinate, and the pressure value corresponding to the point of maximum slope, peak value, or trough value between the peak and trough is used as the abscissa. However, due to body movement, muscle contraction, white noise introduced by the sensor, and respiratory interference during measurement, some outliers may appear. These outliers directly affect the measurement results. Therefore, before estimating blood pressure, these outliers need to be removed and interpolated. Interpolation is usually performed at the pressure value corresponding to the outlier, but this pressure value may not be the pressure value corresponding to the point of maximum slope, peak value, or trough value between the peak and trough.

[0030] Photoplethysmography (PPG) uses photoelectric technology to record changes in blood volume in the microvessels under the skin caused by cardiac contraction and relaxation. It is a non-invasive optical biomonitoring technique that can effectively detect the cardiac cycle and other cardiovascular parameters.

[0031] Both blood pressure oscillatory waveform (BPOS) and pulsed plasma glucose (PPG) signals are caused by the contraction and relaxation of the heart. Therefore, BPOS and PPG signals share the same cardiac cycle, although there will be a time delay depending on the acquisition location. When extracting the envelope of the BPOS signal, the initial and final segments typically have smaller signal amplitudes, making it easy to misinterpret the peak and trough points of the blood pressure signal. Furthermore, for blood pressure signals of poor quality or exhibiting jitter, outliers are more likely to appear when extracting the envelope.

[0032] To facilitate understanding of this embodiment, the embodiments of the present invention will be described in detail below.

[0033] Example 1:

[0034] Figure 1 This is a flowchart of a method for determining the blood pressure signal envelope provided in Embodiment 1 of the present invention.

[0035] Reference Figure 1 Methods for determining the blood pressure signal envelope include:

[0036] Step S101: Acquire the blood pressure signal and photoplethysmography signal of the target object simultaneously.

[0037] Here, the blood pressure signal is measured by a blood pressure monitor. The PPG sensor cannot be placed at the rear of the cuff; it can be placed at the front of the cuff, on the other non-inflation arm or finger, or at a location easily where PPG signals can be collected, such as the earlobe or forehead. A measurement method using the left arm for compression and the right index finger placed on the PPG sensor can be employed.

[0038] Step S102: Extract the effective blood pressure signal segment from the blood pressure signal and calculate the periodic heart rate in the effective blood pressure signal segment; wherein, the effective blood pressure signal segment is a blood pressure signal with peak points or trough points and periodicity.

[0039] In one embodiment, step S102, which involves extracting the effective blood pressure signal segment from the blood pressure signal and calculating the periodic heart rate within the effective blood pressure signal segment, includes:

[0040] Based on peak detection, extreme points in the blood pressure signal are extracted; extreme points are peak points and / or trough points.

[0041] Based on the extracted extreme points, the effective blood pressure signal segment is determined.

[0042] Determine the sampling time of the extreme point, calculate the time difference between two adjacent extreme points, and determine the time difference as the periodic heart rate.

[0043] Here, the time difference between two adjacent extreme points is the heart rate HR_BP for a single cycle.

[0044] Step S103: Based on the heart rate of all cycles, determine the effective photoplethysmography (PPG) signal segment; wherein, the effective PPG signal segment is the PPG signal aligned with the effective blood pressure signal segment through the heart rate.

[0045] In one embodiment, reference is made to Figure 2 and Figure 3 In step S103, the step of determining the effective photoplethysmography signal segment based on all heart rate cycles includes:

[0046] Step S201: Determine the start and end times of the photoplethysmography signal segment.

[0047] Here, the steps for determining the start and end times of the photoplethysmography signal segment include:

[0048] Obtain the minimum and maximum sampling times within the effective blood pressure signal segment.

[0049] Here, the minimum sampling time of the effective blood pressure signal segment is the minimum sampling time of the extreme points of the effective blood pressure signal segment, and the maximum sampling time of the effective blood pressure signal segment is the maximum sampling time of the extreme points of the effective blood pressure signal segment.

[0050] The start time of the photoplethysmography signal segment is determined based on the minimum sampling time, where,

[0051] Here, since the blood pressure signal and photoplethysmography (PPG) signal are acquired simultaneously, their time delay generally does not exceed one cardiac cycle. Therefore, the PPG signal segment is widened based on the effective blood pressure signal segment to cover the entire effective blood pressure signal segment. The first preset empirical value can be set according to the actual situation, generally 1-2 is sufficient.

[0052] The end time of the effective photoplethysmography signal segment is determined based on the maximum sampling time, where,

[0053] Here, the second preset experience value can be set according to the actual situation, generally 1-2 is sufficient.

[0054] The average heart rate is the average of the cyclic heart rate within the effective blood pressure signal segment.

[0055] Here, the average heart rate HR_BP_avg is the average of all HR_BP values.

[0056] Step S202: Calculate the photoplethysmography periodic heart rate of the photoplethysmography signal segment.

[0057] Here, the periodic heart rate of the optical end volumetric signal is the difference between two adjacent peak points.

[0058] Step S203: Based on the photoplethysmography cycle heart rate and the cycle heart rate, determine the photoplethysmography signal segment aligned with the effective blood pressure signal segment.

[0059] Here, Dynamic Time Warping (DTW) is an elasticity measure based on dynamic programming. It calculates the similarity between two time series by warping the time series, achieving a "one-to-many" matching. The larger the data volume, the higher the computational complexity. When blood pressure and PPG signals are acquired simultaneously, their cardiac cycles are exactly the same. However, since the interval between heartbeats varies with different heartbeats, heart rate alignment is used to align the effective blood pressure signal segment and the photoplethysmography (PPG) signal segment. By extracting 10 to 30 heart rates per measurement, the heart rate of the effective blood pressure signal segment and the PPG signal segment can be accurately aligned, reducing computational complexity.

[0060] Step S204: The determined photoplethysmography signal segment is identified as the effective photoplethysmography signal segment.

[0061] In one embodiment, reference is made to Figure 4 Step S204, the step of determining the identified photoplethysmography (PPG) signal segment as a valid PPG signal segment, includes:

[0062] Obtain the photoplethysmography (PPG) periodic heart rate and the periodic heart rate, and calculate the distance between any two points in the PPG periodic heart rate and the periodic heart rate according to the following formula (1):

[0063] d(i,j)=||HR_BP i -HR_PPG j || W (1)

[0064] Where d(i,j) is the distance between any two points in the photoplethysmography periodic heart rate and the periodic heart rate, i = 1, 2, ..., n, j = 1, 2, ..., m, n is the maximum value of i, and m is the maximum value of j; HR_BP i ={HR_BP1,HR_BP2,…,HR_BP n} represents the periodic heart rate set; HR_PPG j ={HR_PPG1,HR_PPG2,…,HR_PPG m} represents the photoplethysmography periodic heart rate set; W is a variable parameter, when W=1, the distance is the Manhattan distance; when W=2, the distance is the Euclidean distance.

[0065] Here, you can choose between Manhattan distance or European distance depending on your actual situation.

[0066] The distance matrix D is determined based on the following formula (2):

[0067]

[0068] Based on matrix D, the optimal regularized path is calculated according to the following formula (3):

[0069] P best ={P1,P2,…,P k ,…,P K} (3)

[0070] Among them, P best For the optimal regularized path; P best ={P1,P2,…,P k ,…,P K} represents HR_BP i With HR_PPG jAlignment; K is the number of paths, max(n,m)≤K≤n+m-1.

[0071] The dynamic time warped distance is calculated based on the following formula (4):

[0072]

[0073] Among them, DTW(HR_BP) i ,HR_PPG j ) represents the dynamic time warping distance, which makes HR_BP i and HR_PPG j The cumulative distance value is the smallest.

[0074] In one embodiment, reference is made to Figure 5 In step S204, the step of determining the identified photoplethysmography (PPG) signal segment as a valid PPG signal segment further includes:

[0075] Based on the distance between any two points in the photoplethysmography (PPG) cycle heart rate and the dynamic time warping distance, the minimum cumulative distance and alignment path coordinates between the PPG signal segment and the effective blood pressure signal segment are determined.

[0076] Based on the alignment path coordinates, periodic heart rate, photoplethysmography periodic heart rate, the start time of the periodic heart rate, and the start time of the photoplethysmography periodic heart rate, matrix E is determined based on the following formula (5):

[0077]

[0078] Wherein, HR_BP_loc is the coordinate after alignment of the effective blood pressure signal segment, HR_PPG_loc is the coordinate after alignment of the photoplethysmography signal segment; HR_BP is the periodic heart rate; HR_PPG is the photoplethysmography periodic heart rate; HR_BP_starttime is the start time of the periodic heart rate; HR_PPG_starttime is the start time of the photoplethysmography periodic heart rate.

[0079] Calculate HR_BP in matrix E k With HR_PPG k Minimum difference value, retrieve the HR_BP_starttime corresponding to the minimum difference value. k With HR_PPG_starttime k The alignment time difference between the photoplethysmography signal segment and the effective blood pressure signal segment is calculated according to the following formula (6):

[0080] Δt = abs(HR_BP_starttime) k -HR_PPG_starttime k (6)

[0081] Where Δt is the alignment time difference.

[0082] When HR_BP_starttime k >HR_PPG_starttime k At that time, the effective blood pressure signal segment remains unchanged, while the photoplethysmography signal segment shifts to the left by Δt.

[0083] When HR_BP_starttime k ≤HR_PPG_starttime k At that time, the effective blood pressure signal segment remains unchanged, while the photoplethysmography signal segment shifts to the right by Δt.

[0084] The photoplethysmography (PPG) signal segment after the movement is determined to be the effective PPG signal segment.

[0085] Step S104: Determine the pressure value corresponding to the effective blood pressure signal segment. Based on the effective blood pressure signal segment, the effective photoplethysmography signal segment, and the pressure value, determine the blood pressure signal envelope of the target object.

[0086] In one embodiment, reference is made to Figure 6 In step S104, the step of determining the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective photoplethysmography signal segment, and the pressure value includes:

[0087] The blood pressure signal envelope of the target object is determined by using the difference between the peak and trough points of the effective blood pressure signal segment as the abscissa and the pressure value corresponding to the point with the largest upward slope of the effective photoplethysmography signal segment as the abscissa.

[0088] In one embodiment, reference is made to Figure 7 and Figure 8 After determining the blood pressure signal envelope, the process also includes:

[0089] Step S301: Based on the photoplethysmography signal, determine whether the blood pressure signal envelope contains outliers.

[0090] Here, outliers are points in the blood pressure signal envelope that show deviations.

[0091] Step S302: If the blood pressure signal envelope contains outliers, remove the outliers.

[0092] Step S303: Interpolate the blood pressure signal envelope after removing outliers.

[0093] Here, a linear interpolation method is used to interpolate the blood pressure signal envelope after removing outliers.

[0094] Step S304: Smooth the interpolated blood pressure signal envelope to obtain the target blood pressure signal envelope.

[0095] Step S305: Calculate the blood pressure value of the target object based on the target blood pressure signal envelope.

[0096] Here, the systolic pressure is calculated based on 67% of the maximum amplitude difference, and the diastolic pressure is calculated based on 60% of the maximum amplitude difference.

[0097] This invention provides a method for determining the blood pressure signal envelope, comprising: acquiring blood pressure signals and photoplethysmography (PPG) signals of a target object simultaneously; extracting effective blood pressure signal segments from the blood pressure signals and calculating the periodic heart rate within the effective blood pressure signal segments; wherein, the effective blood pressure signal segment is a blood pressure signal with peak or trough points and periodicity; determining effective PPG signal segments based on all periodic heart rates; wherein, the effective PPG signal segment is a PPG signal aligned with the effective blood pressure signal segment through heart rate; determining the pressure value corresponding to the effective blood pressure signal segment; and determining the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective PPG signal segment, and the pressure value. In this method, by simultaneously acquiring blood pressure signals and PPG signals, and using the blood pressure signal as a reference to align the PPG signal period with the blood pressure signal period, the accuracy of blood pressure signal envelope extraction is improved, thereby enhancing the accuracy of blood pressure measurement.

[0098] Example 2:

[0099] Figure 9 This is a schematic diagram of the blood pressure signal envelope determination system provided in Embodiment 2 of the present invention.

[0100] Reference Figure 9 The system for determining the blood pressure signal envelope includes:

[0101] Data acquisition module 1 is used to acquire the blood pressure signal and photoplethysmography signal of the target object simultaneously.

[0102] The effective blood pressure signal segment acquisition module 2 is used to extract the effective blood pressure signal segment from the blood pressure signal and calculate the periodic heart rate in the effective blood pressure signal segment; wherein, the effective blood pressure signal segment is a blood pressure signal with peak points or trough points and periodicity;

[0103] The effective photoplethysmography (PPG) signal segment determination module 3 is used to determine the effective PPG signal segment based on the heart rate of all cycles; wherein, the effective PPG signal segment is the PPG signal aligned with the effective blood pressure signal segment through the heart rate.

[0104] The blood pressure signal envelope determination module 4 is used to determine the pressure value corresponding to the effective blood pressure signal segment. Based on the effective blood pressure signal segment, the effective photoplethysmography signal segment, and the pressure value, the blood pressure signal envelope of the target object is determined.

[0105] This invention provides a system for determining the blood pressure signal envelope, comprising: acquiring blood pressure signals and photoplethysmography (PPG) signals of a target object simultaneously; extracting effective blood pressure signal segments from the blood pressure signals and calculating the periodic heart rate within the effective blood pressure signal segments; wherein, the effective blood pressure signal segment is a blood pressure signal with peak or trough points and periodicity; determining effective PPG signal segments based on all periodic heart rates; wherein, the effective PPG signal segment is a PPG signal aligned with the effective blood pressure signal segment through heart rate; determining the pressure value corresponding to the effective blood pressure signal segment; and determining the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective PPG signal segment, and the pressure value. In this method, by simultaneously acquiring blood pressure signals and PPG signals, and using the blood pressure signal as a reference to align the PPG signal period with the blood pressure signal period, the accuracy of blood pressure signal envelope extraction is improved, thereby enhancing the accuracy of blood pressure measurement.

[0106] This invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for determining the blood pressure signal envelope provided in the above embodiments.

[0107] The computer program product provided in this embodiment of the invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation details, please refer to the method embodiments, which will not be repeated here.

[0108] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and apparatus described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0109] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0110] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0111] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0112] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for determining the envelope of a blood pressure signal, characterized in that, include: Acquire the blood pressure signal and photoplethysmography signal of the target object simultaneously; Extract the effective blood pressure signal segment from the blood pressure signal and calculate the periodic heart rate in the effective blood pressure signal segment; wherein, the effective blood pressure signal segment is a blood pressure signal with peak points or trough points and periodicity; Based on all the said cycle heart rates, an effective photoplethysmography (PPG) signal segment is determined; wherein, the effective PPG signal segment is a PPG signal aligned with the effective blood pressure signal segment via heart rate; Determine the pressure value corresponding to the effective blood pressure signal segment, and based on the effective blood pressure signal segment, the effective photoplethysmography signal segment, and the pressure value, determine the blood pressure signal envelope of the target object; The step of determining the effective photoplethysmography signal segment based on all said periodic heart rates includes: Determine the start and end times of the photoplethysmography signal segment; Calculate the photoplethysmography periodic heart rate of the photoplethysmography signal segment; Based on the photoplethysmography cycle heart rate and the cycle heart rate, determine the photoplethysmography signal segment aligned with the effective blood pressure signal segment; The identified photoplethysmography signal segments are defined as effective photoplethysmography signal segments. The step of extracting the effective blood pressure signal segment from the blood pressure signal and calculating the cyclic heart rate within the effective blood pressure signal segment includes: Based on the peak detection method, extreme points in the blood pressure signal are extracted; the extreme points are peak points and / or trough points. Based on the extracted extreme points, the effective blood pressure signal segment is determined; Determine the sampling time of the extreme point, calculate the time difference between two adjacent extreme points, and determine the time difference as the periodic heart rate.

2. The method according to claim 1, characterized in that, After the step of determining the blood pressure signal envelope, the method further includes: Based on the photoplethysmography signal, determine whether the blood pressure signal envelope contains outliers; If the blood pressure signal envelope contains outliers, remove the outliers. Interpolate the envelope of the blood pressure signal after removing outliers; The interpolated blood pressure signal envelope is smoothed to obtain the target blood pressure signal envelope; The blood pressure value of the target object is calculated based on the target blood pressure signal envelope.

3. The method according to claim 1, characterized in that, The step of determining the start and end times of the photoplethysmography signal segment includes: Obtain the minimum and maximum sampling times within the effective blood pressure signal segment; The start time of the photoplethysmography signal segment is determined based on the minimum sampling time, wherein, ; The end time of the effective photoplethysmography signal segment is determined based on the maximum sampling time, wherein, ; The average heart rate is the average value of the cyclic heart rate within the effective blood pressure signal segment.

4. The method according to claim 3, characterized in that, The step of determining the identified photoplethysmography (PPG) signal segment as a valid PPG signal segment includes: Obtain the photoplethysmography-cycled heart rate and the periodic heart rate, and calculate the distance between any two points in the photoplethysmography-cycled heart rate and the periodic heart rate according to the following formula: in, The distance between any two points within the photoplethysmography periodic heart rate and the periodic heart rate is given. , n is the maximum value of i, and m is the maximum value of j; For periodic heart rate sets; The distance is the photoplethysmography periodic heart rate set; W is a variable parameter, when W=1, the distance is the Manhattan distance; when W=2, the distance is the Euclidean distance; Based on the distance, determine the distance matrix D: Based on the matrix D, the optimal normalized path is calculated according to the following formula: in, This is the optimal regularized path; express and Alignment; K is the number of paths. ; The dynamic time-warped distance is calculated based on the following formula: in, The dynamic time warping distance is such that... and The cumulative distance value is the smallest.

5. The method according to claim 4, characterized in that, The step of determining the identified photoplethysmography (PPG) signal segment as a valid PPG signal segment further includes: Based on the photoplethysmography (PPG) cycle heart rate and the distance between any two points in the PPG cycle heart rate and the dynamic time warping distance, the minimum cumulative distance and alignment path coordinates between the PPG signal segment and the effective blood pressure signal segment are determined. Based on the alignment path coordinates, the periodic heart rate, the photoplethysmography periodic heart rate, the start time of the periodic heart rate, and the start time of the photoplethysmography periodic heart rate, matrix E is determined: in, The coordinates of the effective blood pressure signal segment after alignment. The coordinates of the photoplethysmography signal segment after alignment; The heart rate during the cycle; The photoplethysmography periodic heart rate; The starting time of the said cycle heart rate; The start time of the photoplethysmography-cycled heart rate; Calculate the matrix E in and The minimum difference value is obtained by finding the value corresponding to the minimum difference value. and The alignment time difference between the photoplethysmography signal segment and the effective blood pressure signal segment is calculated according to the following formula: in, The alignment time difference; when At that time, the effective blood pressure signal segment remains unchanged, while the photoplethysmography signal segment shifts to the left. ; when At that time, the effective blood pressure signal segment remains unchanged, while the photoplethysmography signal segment shifts to the right. ; The photoplethysmography signal segment after the movement is determined to be a valid photoplethysmography signal segment.

6. The method according to claim 1, characterized in that, The step of determining the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective photoplethysmography signal segment, and the pressure value includes: The blood pressure signal envelope of the target object is determined by using the difference between the peak and trough points of the effective blood pressure signal segment as the ordinate and the pressure value corresponding to the point with the largest upward slope of the effective photoplethysmography signal segment as the abscissa.

7. A system for determining the envelope of a blood pressure signal, characterized in that, include: The data acquisition module is used to acquire the blood pressure signal and photoplethysmography signal of the target object simultaneously. An effective blood pressure signal segment acquisition module is used to extract the effective blood pressure signal segment from the blood pressure signal and calculate the periodic heart rate in the effective blood pressure signal segment; wherein, the effective blood pressure signal segment is a blood pressure signal with peak points or trough points and periodicity; An effective photoplethysmography (PPG) signal segment determination module is used to determine an effective PPG signal segment based on all the said cycle heart rates; wherein, the effective PPG signal segment is a PPG signal aligned with the effective blood pressure signal segment through heart rate; A blood pressure signal envelope determination module is used to determine the pressure value corresponding to the effective blood pressure signal segment, and to determine the blood pressure signal envelope of the target object based on the effective blood pressure signal segment, the effective photoplethysmography signal segment and the pressure value. The effective photoplethysmography (PPG) signal segment determination module is further configured to determine the start and end times of the PPG signal segment; calculate the PPG cycle heart rate of the PPG signal segment; determine the PPG signal segment aligned with the effective blood pressure signal segment based on the PPG cycle heart rate and the cycle heart rate; and determine the determined PPG signal segment as the effective PPG signal segment. The effective blood pressure signal segment acquisition module is further configured to extract extreme points in the blood pressure signal based on peak detection; the extreme points are peak points and / or valley points; based on the extracted extreme points, the effective blood pressure signal segment is determined; the sampling time of the extreme points is determined, the time difference between two adjacent extreme points is calculated, and the time difference is determined as the periodic heart rate.

8. An electronic device comprising a memory and a processor, wherein the memory stores a computer program executable on the processor, characterized in that, When the processor executes the computer program, it implements the method described in any one of claims 1-6.

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