CN112998678B - Wearable device boosting type blood pressure measurement and calculation method - Google Patents
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Abstract
The invention discloses a wearable device boosting type blood pressure measuring and calculating method, which comprises an inflation control stage and a blood pressure calculating stage and is characterized in that: the control inflation phase comprises: performing rapid inflation, and performing open-loop control on PWM (pulse-width modulation) through setting a speed threshold when a pressure value is lower than a set threshold; or linear inflation, when the static pressure value reaches a set threshold value, the stable linear inflation process is realized by utilizing closed-loop control to adjust PWM; the invention provides a pressure boosting type blood pressure measuring and calculating method, which achieves a stable inflation process through a pid control algorithm, collects pulse wave signals to process in the inflation process, preliminarily calculates a blood pressure value by adopting an amplitude coefficient method, calculates the blood pressure value by combining an amplitude normalization method and a characteristic compensation method, compensates for average pressure deviation caused by other factors, avoids uncomfortable experience brought by a pressure reducing type blood pressure measuring method, improves the measuring efficiency, and increases the comfort level and the convenience of blood pressure measurement of wearable equipment.
Description
Technical Field
The invention belongs to a blood pressure detection method, and particularly relates to a wearable device which extracts pulse wave signals to detect blood pressure in a boosting process and calculates heart rate according to the pulse waves.
Background
Cardiovascular disease is one of the most common diseases in the world, and with increasing age, more and more people suffer from hypertension. Blood pressure is an important physiological parameter index reflecting cardiovascular function, and has very important clinical diagnosis value. The blood pressure detection method comprises invasive blood pressure detection and noninvasive blood pressure detection. Invasive blood pressure belongs to a direct measurement method, although the prior art is mature, the invasive blood pressure has some pains and is currently applied to critical patients or patients needing surgical treatment. Therefore, the non-invasive blood pressure measurement method is widely used. The oscillometric blood pressure measurement has two modes of pressure rise measurement and pressure reduction measurement. The blood pressure reduction measurement comprises two stages, namely an inflation stage and a deflation stage, wherein the part to be measured is inflated and pressurized to be in an artery closed state, and then a pressure oscillation wave signal generated by artery pulsation is collected in the deflation stage to be analyzed to finish measurement. The pressure-boosting measurement mode is to acquire the oscillation wave signals and process the signals in real time during the pressurization process, and the gas is quickly released once the test is finished. The pressure value of the end of inflation needs to be preset in the depressurization measurement mode, discomfort of a tested person can be increased if the preset pressure value is too high, and the measurement efficiency is low if the preset pressure value is too low.
Oscillography is generally to calculate an actual blood pressure value by a curve fitting method in cooperation with an amplitude coefficient method, collect pulse oscillation waves in the boosting process, identify peak sequences and valley sequences of the pulse oscillation waves, perform curve fitting according to the peak sequences in some cases, and perform curve fitting according to the amplitude sequences in some cases. The pressure value corresponding to the maximum amplitude or peak value of the pulse wave is the average pressure; and then calculating the systolic pressure amplitude and the diastolic pressure amplitude by using the maximum amplitude and the amplitude coefficient, and finding out the corresponding static pressure value by combining the fitting curve, namely the corresponding systolic pressure and diastolic pressure. If the original pressure value has deviation, the test result is influenced to a certain degree.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a pressure-boosting blood pressure measuring device and a pressure-boosting blood pressure measuring method. And adjusting the PWM of the air pump to achieve a stable inflation process through a pid control algorithm, acquiring a pulse wave signal in a boosting process to perform real-time analysis, calculating systolic pressure and diastolic pressure by using curve fitting in combination with an amplitude coefficient method and a compensation method, and calculating heart rate.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a wearable device boost blood pressure measurement and calculation method comprises a control inflation stage and a blood pressure calculation stage, and is characterized in that: the control inflation phase comprises:
carrying out quick inflation, and carrying out open-loop control on the PWM through setting a speed threshold when the pressure value is lower than the set threshold;
or linear inflation, when the static pressure value reaches a set threshold value, a stable linear inflation process is realized by using closed-loop control to adjust PWM;
the blood pressure calculation stage comprises the following steps:
s1, obtaining pulse oscillation wave signals, removing noise such as baseline drift and the like through the combination of Butterworth high-pass filtering and low-pass filtering, and extracting relatively pure pulse wave signals; simultaneously, extracting a direct current component in the signal by using a Butterworth low-pass filter as a static pressure reference value;
s2, peak value/valley value detection, namely detecting peak value and valley value of the processed pulse wave signals, searching the original pulse wave signal sequences one by one in a one-by-one searching mode, judging the ascending and descending processes of the sequences, identifying a peak value point if the ascending process reaches a certain length and the amplitude value reaches a set threshold value, taking the point of starting to ascend as a valley value point, and taking the difference value of the two as the amplitude value. The peak points correspond to the valley points, the amplitude points and the pulse times one by one, and the heart rate is calculated according to the pulse times;
s3, smoothing and fitting the amplitude curve, namely filtering the amplitude curve by using median filtering and mean filtering, and fitting the processed amplitude curve by using linear interpolation fitting to obtain a smoother and more complete pulse wave amplitude curve;
s4, calculating a blood pressure value, namely identifying a static pressure value corresponding to the maximum value of the amplitude curve as an average pressure, calculating the amplitudes of diastolic pressure and systolic pressure by using an amplitude coefficient method, and acquiring the static pressure value corresponding to the amplitude curve as a corresponding blood pressure value;
s5, blood pressure compensation, namely compensating the diastolic pressure by using a coefficient method, and compensating the systolic pressure by using an amplitude normalization proportion method;
s6, finishing measurement, wherein the condition for judging the finishing of the measurement comprises that the corresponding diastolic pressure and systolic pressure or the pressure of the measured part exceeds the preset maximum pressure value or the measurement duration exceeds the preset maximum measurement duration, finishing the measurement and quickly deflating.
Optionally, the step of linear inflation is: using a pid control method, wherein the pid control method formula is as follows:
kp is a proportional coefficient, ki is an integral coefficient, kd is a differential coefficient, and e (t) is a deviation signal. The Pid control method controls a controlled object by forming a deviation between a target value and an actual output value and linearly combining the proportion, integral, and differential of the deviation to form a control amount.
Optionally, the butterworth high-pass filtering processing in step S1 specifically includes the following steps:
setting the pass band cut-off frequency, pass band maximum attenuation, stop band minimum attenuation and sampling frequency
Designing an analog Butterworth high-pass/low-pass filter (prototype filter H (s))
Bilinear transformation method:
high-pass:
low-pass:
system function H (z) to get digital filter: denominator a (n), numerator b (m)
Solving a linear difference equation of the constant coefficients to obtain a filtered signal y (n):
optionally, the step S3 of median filtering specifically includes the following steps:
setting the length of a filter, namely the number of sequence elements transmitted into the filter each time;
sorting the incoming sequences from large to small;
and returning the intermediate value of the sorted sequence.
Optionally, the step S3 of mean filtering specifically includes the following steps:
setting the length of a filter, namely the number of sequence elements transmitted into the filter each time;
the average of the incoming sequence is calculated and returned.
Optionally, the linear interpolation fitting method in step S3 mainly performs numerical estimation according to data near left and right of a point to be interpolated in the one-dimensional data sequence, where the point (x) is known 0 ,y 0 )、(x 1 ,y 1 ) And solving a y value corresponding to the interpolation point x by an equal proportion method, wherein the formula is as follows:
optionally, in step S4, the initial systolic pressure and the diastolic pressure are calculated by an amplitude coefficient method.
Optionally, in step S5, the initial blood pressure value is compensated by a coefficient method and an amplitude normalization ratio method, so as to obtain a more accurate result.
Optionally, in step S6, the condition of ending the measurement includes that the calculated result exceeds a preset maximum pressure value or exceeds a maximum measurement time. The preset maximum pressure value is 256mmHg and the maximum measurement time is preset to 70s.
The invention provides a pressure boosting type blood pressure measuring and calculating method, which achieves a stable inflation process through a pid control algorithm, collects pulse wave signals to process in the inflation process, preliminarily calculates a blood pressure value by adopting an amplitude coefficient method, calculates the blood pressure value by combining an amplitude normalization method and a characteristic compensation method, compensates for average pressure deviation caused by other factors, avoids uncomfortable experience brought by a pressure reducing type blood pressure measuring method, improves the measuring efficiency, and increases the comfort level and the convenience of blood pressure measurement of wearable equipment.
Drawings
FIG. 1 is a general flow diagram of the present invention.
Fig. 2 is a rapid inflation flow chart.
FIG. 3 is a schematic diagram of pid control.
Fig. 4 is a graph of inflation.
Fig. 5 is a diagram showing the effect of extracting and filtering pulse waves.
Fig. 6 is a graph of fft spectra before and after filtering.
Fig. 7 shows a dc component in the extracted signal.
Fig. 8 is a peak/valley detection flow chart.
Fig. 9 is a graph of the measurement results.
Detailed Description
The invention is described in further detail below with reference to the accompanying examples.
The specific embodiment provides a wearable device up-pressure type blood pressure measurement and calculation method, and a flow chart of the method is shown in fig. 1. The blood pressure measuring method is divided into an inflation stage and a calculation stage, the inflation stage can acquire pulse wave signals, and the key point is to control the efficiency and stability of the inflation process; the key point of the calculation stage is that amplitude curve processing, a proportionality coefficient method and various compensation methods are combined to improve the accuracy of blood pressure measurement.
The first stage is an inflation stage, which is divided into rapid inflation and linear inflation, and the rapid inflation can improve the measurement efficiency.
When the pressure value is lower than the set threshold value of 25mmHg, a rapid inflation method is adopted, several groups of speed threshold values are set, and open-loop adjustment is directly carried out on PWM, and the rapid inflation process is shown in figure 2.
4 speed thresholds were set, including 15mmHg/s, 10mmHg/s, 8mmHg/s, and 3mmHg/s. The inflation speed is preferably 3-8mmHg/s, so when the actual inflation speed is more than 15mmHg/s, the PWM duty ratio is directly increased, and the increase amplitude is 5; similarly, when the actual inflation speed is greater than 10mmHg/s, the PWM duty ratio is directly increased, and the increase amplitude is 2; when the actual inflation speed is higher than 8mmHg/s, directly increasing the PWM duty ratio, wherein the increase amplitude is 1; when the actual inflation speed is less than 3mmHg/s, the PWM duty ratio is directly reduced, and the reduction amplitude is 2.
When the pressure value reaches a set threshold value, in order to ensure the stability of the inflation phase and facilitate the acquisition of more stable pulse wave signals, PWM is regulated and controlled in real time through a pid control method so as to further control the inflation process. The control principle is as shown in fig. 3, the target speed is set to be 3.7mmHg/s, and the difference value of the actual speed and the target speed, which is represented by the deviation signal e (t), is a proportional control part and corresponds to a proportional coefficient Kp; the last deviation signal e (t-1) is an integral control part and corresponds to an integral coefficient Ki; the difference of the deviation signals, i.e., e (t) -e (t-1), is a differential control section corresponding to a differential coefficient Kd. The Pid control result is shown in equation (7):
pid_result＝e(t)Kp+e(t-1)Ki+[e(t)-e(t-1)]Kd (7)
the pid control regulates the PWM variation amplitude, which is the result obtained from equation (7).
The inflation phase is complete and the actual inflation curve is shown in figure 4. The inflation process is basically stable, the rising speed is basically stable, and the pressure value basically shows linear increase.
The second phase is a calculation phase, and firstly, pulse wave signals are acquired.
The pulse wave signals are extracted from the original inflation signals through the Butterworth high-pass filter, because the inflation signals belong to time domain signals, baseline wander can be removed through the high-pass filter to obtain the pulse wave signals, the 3-order Butterworth high-pass filter with the cutoff frequency of 0.5Hz is designed, the baseline wander is removed, and the extracted pulse wave signals are shown in figure 5.
The extracted pulse wave signals also have a plurality of high-frequency noise signals, and the extracted pulse wave signals are processed through a Butterworth low-pass filter, so that the signals are purer and smoother. And a 7-order low-pass filter with the cut-off frequency of 3.5Hz is designed to further process the signals, filter redundant high-frequency noise and extract a purer pulse wave signal. The filtering effect is shown in fig. 5, and the spectrogram before and after filtering is shown in fig. 6.
The direct current signal is obtained through the Butterworth low-pass filter, the cut-off frequency is set to be 0.4Hz due to the fact that the human pulse wave signal is about 0.7H-3Hz, and the direct current component in the original signal can be effectively extracted to serve as a reference static pressure value, as shown in figure 7.
Next, peak/valley detection is performed, and a detection starting point is determined first, and the pulse wave signal may not be acquired or may be weak in the previous inflation process, so that the detection starting point needs to be determined before peak/valley detection is performed. The minimum detection position is set to 170, and when the inflation pressure value reaches 35mmHg from this detection position, peak/bottom detection is started. And searching one by utilizing the distribution characteristics of the peak value/valley value. The peak/bottom values are detected, and the amplitude and the number of pulse waves are calculated. Two thresholds are set, one being a rise length threshold of 5 and the other being an amplitude threshold of 20. As shown in fig. 8, where data is raw signal data, up _ cnt represents the rise length, and amp is the amplitude variation from valley to peak, i.e., data (i) -data (i-up _ cnt); the position corresponding to the peak value is i, and the peak value is data (i); the position corresponding to the valley value is i-up _ cnt, and the valley value is data (i-up _ cnt). And recording the amplitude of the current pulse wave every time the peak value/valley value is recorded, and increasing the number of the pulse waves one by one.
The heart rate is the number of beats of the heart per minute, and the pulse is the number of pulse beats per minute. The values of both are generally equal. Therefore, the calculation method of the heart rate is calculated through the pulse wave detection condition. The ratio of the sum of the time distances to the number of pulse waves is obtained by calculating the time distance between every two adjacent pulse waves (from the starting position to the ending position). And finally, calculating the pulse beating times per minute by combining the signal sampling frequency of 50Hz so as to obtain the heart rate value. Namely, bmp = (60 x 50)/mean pulsation, where mean pulsation = distance in time/number of pulses.
In the actual detection process, some oscillation phenomena may exist, the amplitude is not very stable, and the original amplitude is subjected to filtering smoothing by adopting a median filtering mode and a mean filtering mode.
And (4) median filtering, wherein the window length is set to 5, namely, every 5 amplitude sequences are sorted once to screen the median. The amplitudes of the first and last bits in the sequence are kept constant and the amplitudes of the second and last-to-last bits are calculated using the average of the three amplitudes. Assuming that the original amplitude sequence is data, the total length of the sequence is N, and the filtered sequence is data1, filtering is performed according to the following rules.
data1(0)＝data(0)；
data1(1)＝(data(0)+data(1)+data(2))/3；
data1(N-2)＝(data(N-3)+data(N-2)+data(N-1))/3；
data1(N-1)＝data(N-1)
data1 (i) is two amplitude values before and after the point i is taken as the center, and the 5 values are sorted from large to small, so that data1 (i) is the middle value of the 5 sorted amplitude values.
And (4) mean filtering, namely smoothing the original data by using a mean mode. The window length is set to 3 and the initial and end values remain unchanged. Others are processed by averaging every 3 numbers. Assuming that the original sequence is data, the sequence length is N, and the filtered sequence is data1, the average filtering rule is as follows:
data1(0)＝data(0)；
data1(N-1)＝data(N-1)；
data1(i)＝(data(i-1)+data(i)+data(i+1))/3
the amplitude curve after the filtering treatment is smoother, and the oscillation phenomenon of the pulse wave is improved.
The linear interpolation fitting can make the original curve more complete, the estimation of unknown data points through the known data sequence can play a role in compensating missing data, and the proportion is mainly distributed according to the distance of the known points. Firstly, extending an original amplitude sequence, wherein the initial position is 1, and the initial amplitude is 0; the end position is the length of the original data sequence and the end amplitude is also 0. Then, a scaling factor k and an offset b are determined. The magnitude sequence is y (n), the magnitude position sequence is x (n), and i denotes a certain sequence point.
distance＝x(i)-x(i-1)
value＝y(i)-y(i-1)
k(i-1)＝value/distance
b(i-1)＝y(i-1)-k(i-1)*x(i-1)
The amplitude curve after filtering and linear interpolation fitting is smoother and more complete than the original amplitude curve, and better presents the envelope shape of the pulse wave, such as the diamond connection curve in fig. 9, the diamond-shaped mark points on the curve are the amplitude points of the original amplitude after median filtering and mean filtering, and the original amplitude sequence is the five-pointed star connection line in fig. 9. The original amplitude sequence has a certain oscillation phenomenon, is smoother after filtering treatment, can reflect the oscillation change trend of the original pulse wave, and has a more complete amplitude curve after linear interpolation, thereby realizing the pulse wave envelope in the whole measurement process.
The position where the amplitude of the pulse wave is the maximum is the mean arterial pressure abp, so the mean pressure position is determined by the amplitude, the mean pressure position is determined by obtaining the maximum amplitude of the pulse wave, and the pressure value corresponding to the current position is the magnitude of the mean pressure, as shown in the blue five-pointed star label of fig. 9.
Calculating blood pressure values by combining a proportionality coefficient method and various compensation methods, detecting initial dbp and sbp by the proportionality coefficient method, taking the abp position as a reference point, and setting thresholds of the dbp and the sbp by the proportionality coefficient. The amplitude coefficients are referred to in the literature, but are empirical values, and the different test equipment configurations may vary greatly. In connection with the study of the present invention, the sbp amplitude coefficient was set to 0.69 and the dbp amplitude coefficient was set to 0.33. Therefore, the threshold value of the amplitude of sbp is 0.69 times of the amplitude of abp; the threshold amplitude value of dbp is 0.33 times the amplitude of abp.
The reference value is the average pressure, the reference position is the average pressure position, and the detection positions of the two are different. The detection of sbp is after the average pressure position, and the detection is from the average pressure position back to the end. And dbp is detected from the start point to the end of the average pressure position. When the first blood pressure value is lower than the amplitude threshold value, the corresponding blood pressure value is the corresponding initial sbp or dbp, the sbp and dbp are distributed at two sides of the abp, such as the dark five-pointed star marked position in fig. 9, and the dark origin is the corresponding sbp and dbp position in the amplitude curve.
Sbp and dbp obtained by the initial proportionality coefficient method may have a certain error with an actual value, so the error needs to be compensated, a threshold coefficient compensation method is adopted for dbp, and an amplitude normalization compensation method is adopted for sbp.
The threshold coefficient compensation method is characterized in that the compensation is carried out by setting a reference value, the compensation position takes a dbp position as a reference, the compensation reference value is about 70 basically, the value is set to 68 in the embodiment, and a proportionality coefficient of 0.67 is set by calculating the difference between the original dbp value and the reference threshold value to realize the compensation effect on the dbp. The compensation reference values are as indicated by the light colored five-pointed star in fig. 9.
The amplitude normalization compensation method utilizes the relationship between the pulse wave oscillation amplitude and the pressure value to obtain a normalization parameter, obtains an average value of 7 maximum amplitudes, then utilizes the normalization parameter to determine a blood pressure value corresponding to the average value, and finally utilizes linear transformation to obtain a final sbp value, wherein the linear parameter is linerparameter = {0.5685,29.9947}. Namely that
Normalized parameter = pulse wave maximum amplitude/maximum blood pressure value
Normalized blood pressure value = amplitude mean/normalized parameter
Final blood pressure value = normalized blood pressure value linerparameter [0] + linerparameter [1]
The result is output, as shown in fig. 9, the actual reference blood pressure of the measurement data is sbp =110, dbp =68; the original amplitude coefficient method measurement results are sbp =139, sbp =82, abp =124, the whole is shifted upwards, and the compensated measurement results are sbp =110, dbp =76.
The above examples are further detailed descriptions of the present invention with reference to specific implementations, and it should not be construed that the present invention is limited thereto. It will be apparent to those skilled in the art that various modifications, additions, substitutions, and substitutions can be made without departing from the spirit of the invention.
Claims (6)
1. A storage medium including a wearable device pressure-increasing blood pressure measurement and calculation method comprises a control inflation stage and a blood pressure calculation stage, and is characterized in that: the control inflation phase comprises:
carrying out quick inflation, and carrying out open-loop control on the PWM through setting a speed threshold when the pressure value is lower than the set threshold;
or linear inflation, when the static pressure value reaches a set threshold value, a stable linear inflation process is realized by using closed-loop control to adjust PWM;
the blood pressure calculating stage comprises the following steps:
s1, obtaining pulse oscillation wave signals, and extracting relatively pure pulse wave signals through combining Butterworth high-pass filtering and low-pass filtering; simultaneously, extracting a direct current component in the signal by using a Butterworth low-pass filter as a static pressure reference value;
s2, peak value/valley value detection, namely detecting peak value and valley value of the processed pulse wave signals, searching the original pulse wave signal sequence one by one in a one-by-one searching mode, judging the ascending and descending processes of the sequence, identifying a peak value point if the ascending process reaches a certain length and the amplitude value reaches a set threshold value, taking the point where the ascending starts as a valley value point, taking the difference value of the peak value point and the valley value point as an amplitude value, corresponding the peak value point, the amplitude value point and the pulse frequency one by one, and calculating the heart rate according to the pulse frequency;
s3, smoothing and fitting the amplitude curve, namely filtering the amplitude curve by using median filtering and mean filtering, and fitting the processed amplitude curve by using linear interpolation fitting to obtain a smoother and more complete pulse wave amplitude curve;
s4, calculating a blood pressure value, identifying a static pressure value corresponding to the maximum value of the amplitude curve as an average pressure, calculating the amplitudes of diastolic pressure and systolic pressure by an amplitude coefficient method, and acquiring the corresponding static pressure value as a corresponding blood pressure value;
s5, blood pressure compensation, namely compensating the diastolic pressure by using a coefficient method, setting the compensation position to be 68 by taking the dbp position as a reference, and setting a proportionality coefficient to be 0.67 by calculating the difference between the original dbp value and a reference threshold value to realize the compensation effect on dbp; meanwhile, the systolic pressure is compensated by using an amplitude normalization proportion method, the amplitude normalization compensation method obtains normalization parameters by using the relationship between the pulse wave oscillation amplitude and the pressure value, obtains the average value of 7 maximum amplitudes, determines the blood pressure value corresponding to the average value by using the normalization parameters, and finally obtains the final sbp value by using linear transformation, wherein the normalization parameters = the pulse wave maximum amplitude/maximum blood pressure value, the normalization blood pressure value = the amplitude average value/normalization parameters, and the final blood pressure value = the normalization blood pressure value 0.5685+29.9947;
s6, finishing measurement, namely judging that the conditions for finishing the measurement comprise that the corresponding diastolic pressure and systolic pressure or the pressure of the measured part exceed the preset maximum pressure value or the measurement duration exceeds the preset maximum measurement duration, finishing the measurement and quickly deflating;
the steps of linear inflation are as follows: forming a deviation by a target value and an actual output value by using a pid control method, linearly combining the proportion, the integral and the differential of the deviation to form a control quantity, and controlling a controlled object;
the Butterworth high-pass filtering and the low-pass filtering in the step S1 are combined to obtain the pulse oscillation signal in the original inflation signal, and the method specifically comprises the following steps:
setting indexes: pass-band cut-off frequency, pass-band maximum attenuation, stop-band minimum attenuation, and sampling frequency;
designing an analog Butterworth high-pass/low-pass filter;
bilinear transformation method: obtaining a system function of the digital filter;
linear difference equation of solution coefficients: obtaining a filtered signal;
and S5, compensating the initial blood pressure value by a coefficient method and an amplitude normalization proportion method to obtain a more accurate result.
2. The storage medium of claim 1, wherein the wearable device comprises a step-up blood pressure measurement and calculation method, and wherein: the median filtering in step S3 specifically includes the following steps:
1) Setting the length of a filter, namely the number of sequence elements transmitted each time;
2) Sequencing the incoming sequences from large to small;
3) And returning the intermediate value of the reordered sequence.
3. The storage medium containing the wearable device boost blood pressure measurement and calculation method of claim 1, wherein: the specific steps of the average filtering in the step S3 are as follows:
setting the length of a filter, namely the number of sequence elements transmitted into the filter each time;
the average of the incoming sequence is calculated and returned.
4. The storage medium containing the wearable device boost blood pressure measurement and calculation method of claim 1, wherein: the linear interpolation fitting method in step S3 is to perform numerical estimation mainly according to data near left and right of a point to be interpolated in the one-dimensional data sequence, and when the points (x 0, y 0) and (x 1, y 1) are known, the y value corresponding to the interpolation point x is obtained by using an equal proportion method, where x belongs to (x 0, x 1).
5. The storage medium containing the wearable device boost blood pressure measurement and calculation method of claim 1, wherein: and S4, calculating initial systolic pressure and diastolic pressure by using an amplitude coefficient method.
6. The storage medium containing the wearable device boost blood pressure measurement and calculation method of claim 1, wherein: in step S6, the measurement ending condition includes that the calculated result exceeds a preset maximum pressure value or exceeds a maximum measurement time, the preset maximum pressure value is 256mmHg, and the maximum measurement time is preset to 70S.
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