WO2017092020A1 - Blood pressure measurement method and apparatus - Google Patents

Abstract

A blood pressure measurement method and apparatus (30). The method comprises: collecting an ECG signal and a PPG signal of a user (110); acquiring a PTT collection duration (120); if it is determined that the PTT collection duration is greater than or equal to a pre-set PTT validity duration, acquiring a blood pressure measurement value of the user based on a PTT blood pressure computation model (130); if it is determined that the PTT collection duration is less than the pre-set PTT validity duration, acquiring a PPG collection duration (140); and if it is determined that the PPG collection duration is greater than or equal to a pre-set PPG validity duration, acquiring the blood pressure measurement value of the user based on a PPG blood pressure computation model (150). The blood pressure measurement apparatus (30) comprises an ECG signal collection circuit (31), a PPG signal collection circuit (32), a processor (33) and a display module (34). Adopting the blood pressure measurement apparatus (30) can improve the efficiency of blood pressure measurement, and even if poor contact or electrode detachment occurs to an ECG signal, a blood pressure measurement value of a user can also be obtained.

Description

Blood pressure measuring method and device Technical field

The present invention relates to the field of medical technology, and in particular to a blood pressure measuring method and apparatus.

Background technique

Hypertension is the most common type of cardiovascular disease. This disease is getting more and more attention and attention. Blood pressure measurement has become an indispensable means for effective monitoring of hypertension.

In recent years, with the development of mobile medical technology, some indirect measurement methods of blood pressure have emerged, which has improved the convenience of blood pressure measurement. The indirect blood pressure measurement method indirectly obtains blood pressure data such as arterial systolic pressure and arterial diastolic pressure by detecting parameters such as pulsation of the arterial wall and changes in blood vessel volume.

For example, one of the widely used indirect blood pressure measurement methods is a pressure measuring method that uses a pneumatic sleeve to compress a blood vessel. During the inflation of the cuff, once the pressure in the cuff exceeds the Systolic Blood Pressure (SBP), the blood vessel is compressed, the blood flow is blocked, and the pulsation of the artery is not heard at the distal end of the blood vessel. During the deflation of the cuff, when the gas pressure in the cuff is lower than the arterial systolic pressure, the blood vessel is open, the blood flow is restored, and the arterial pulse sound is generated, and the cuff is heard when the first acoustic artery beat sound (ie, auscultation sound) is heard. The gas pressure inside is the arterial systolic pressure. Continue to deflate, when the gas pressure in the cuff is lower than the Diastolic Blood Pressure (DBP), the blood vessels are completely unobstructed, the blood flow is no longer blocked, the arterial pulse sound disappears, and the pressure inside the cuff It is the arterial diastolic pressure.

Another commonly used indirect measurement method for blood pressure is the Oscillometric Method, which uses a cuff to block arterial blood flow. During slow deflation, it detects the pulsating oscillation wave envelope from the blood vessel wall and finds out The inherent relationship between the envelope and arterial blood pressure, in turn, blood pressure data. This method is also widely used in various clinical electronic blood pressure monitors.

However, the above two methods of indirect blood pressure measurement do not get rid of the traditional mode of the inflatable cuff. Each time the blood pressure data is obtained, the cuff is required to be filled and deflated, and the inflatable sleeve is used to compress the blood vessel, so that the human body feels uncomfortable. In addition, when the subject requires multiple measurements in a short period of time or continuous measurements over a long period of time, the patient is inconvenienced.

With the development of new technologies, there have been blood pressure measurement methods that have rid of the traditional mode of inflatable cuffs.

For example, using pulse transit time (PTT) and arterial blood pressure related features, the prior art proposes to use PTT to measure blood pressure, specifically, by collecting the photoplethysmoGraphy (PPG) signal at the finger and Electrocardiogram (ECG) signal of limb lead, calculate PTT of blood from heart to signal acquisition, and establish blood pressure estimation model of arterial blood pressure and pulse transit time, which can calculate real-time blood pressure value of human body and achieve non-invasive continuous measurement. And can completely get rid of the restraint of the sleeve.

However, the method of obtaining blood pressure information using PTT estimation requires the ECG signal. If the ECG lead method used is a limb lead, it may easily occur due to poor contact of the limb, or the ECG electrode may fall off after a long period of non-contact. The ECG signal was not available, which made it impossible to measure blood pressure.

In addition, using the characteristics of the average blood pressure of the population (half the sum of systolic and diastolic blood pressure, ie (SBP+DBP)/2) and the amplitude of heart rate variability under respiratory regulation, it is proposed to use ECG to measure blood pressure. Specifically, the heart rate variation amplitude can be obtained by collecting the ECG signal, and the average blood pressure can be obtained by using the relationship between the average blood pressure of the population and the heart rate variation amplitude. However, obtaining blood pressure information in this way also requires collecting ECG signals, which causes the same problem as the above PTT calculation method for obtaining blood pressure. The ECG signal cannot be obtained due to poor contact or electrode peeling, resulting in inaccurate measurement. blood pressure.

Summary of the invention

Embodiments of the present invention provide a blood pressure measuring method and apparatus for overcoming the problem that the ECG signal cannot be obtained due to poor contact or electrode detachment, so that blood pressure cannot be accurately measured.

The specific technical solutions provided by the embodiments of the present invention are as follows:

In a first aspect, a blood pressure measurement method includes:

Collecting a user's ECG signal and a photoplethysmographic pulse PPG signal;

Obtaining a pulse wave transit time PTT acquisition duration, where the PTT acquisition duration refers to a duration in which the signal quality of the ECG signal satisfies a first preset condition and the signal quality of the PPG signal simultaneously satisfies a second preset condition;

If it is determined that the PTT acquisition duration is greater than or equal to a preset PTT effective duration, acquiring the blood pressure measurement value of the user based on the PTT blood pressure calculation model;

If it is determined that the PTT acquisition duration is less than the preset PTT effective duration, the PPG acquisition duration is obtained, where the PPG acquisition duration refers to a duration in which the signal quality of the PPG signal meets the second preset condition;

If it is determined that the PPG acquisition duration is greater than or equal to a preset PPG effective duration, the blood pressure measurement value of the user is obtained based on the PPG blood pressure calculation model.

In combination with the first aspect, in a first possible implementation manner of the first aspect, the method further includes:

If the PTT acquisition duration is less than the preset PTT effective duration and the PPG acquisition duration is less than the preset PPG effective duration, the ECG acquisition duration is obtained, where the ECG acquisition duration refers to the signal quality of the ECG signal satisfies the first The length of the preset condition;

If it is determined that the ECG acquisition duration is greater than or equal to a preset ECG effective duration, the blood pressure measurement value of the user is acquired based on the ECG blood pressure calculation model.

With reference to the first aspect, in a second possible implementation manner of the first aspect, the blood pressure measurement value of the user is obtained based on a PPG blood pressure calculation model, and specifically includes:

Collecting data for calculating blood pressure in the PTT blood pressure calculation model;

Calculate the PPG correlation coefficient based on the collected data;

And introducing the PPG correlation coefficient and the collected data into the PTT blood pressure calculation model, and obtaining a model for calculating blood pressure according to the PPG signal characteristic value as the PPG blood pressure calculation model;

The PPG signal characteristic value corresponding to the collected PPG signal is substituted into the PPG blood pressure calculation model, and the blood pressure measurement value of the user is calculated.

With reference to the first aspect or any one of the foregoing possible implementation manners, in a third possible implementation manner of the first aspect, the first preset condition is that a lead connection state of the ECG signal is a normal connection state and a signal-to-noise ratio of the ECG signal is less than or equal to a first threshold, or a lead connection state of the ECG signal is a normal connection state and an invalid feature point in the ECG signal accounts for a total of feature points The ratio is less than or equal to the second threshold, or the lead connection state of the ECG signal is a normal connection state and the ECG signal continuously acquires a vertex position of the ECG R wave.

In combination with the first aspect or any of the possible implementations of the first aspect above, in a first aspect In a fourth possible implementation manner, the second preset condition is that a signal to noise ratio of the PPG signal is less than or equal to a third threshold, or an invalid feature point in the PPG signal is occupied by a total of feature points. The ratio is less than or equal to the fourth threshold.

In a second aspect, a blood pressure measuring device includes:

ECG signal acquisition circuit for collecting the ECG signal of the user;

a PPG signal acquisition circuit for collecting the PPG signal of the user;

a processor for obtaining a PTT acquisition duration, where the PTT acquisition duration refers to a duration in which the signal quality of the ECG signal satisfies a first preset condition and the signal quality of the PPG signal simultaneously satisfies a second preset condition;

If it is determined that the PTT acquisition duration is greater than or equal to a preset PTT effective duration, acquiring the blood pressure measurement value of the user based on the PTT blood pressure calculation model;

If it is determined that the PTT acquisition duration is less than the preset PTT effective duration, the PPG acquisition duration is obtained, where the PPG acquisition duration refers to a duration in which the signal quality of the PPG signal meets the second preset condition;

If it is determined that the PPG acquisition duration is greater than or equal to a preset PPG effective duration, acquiring the blood pressure measurement value of the user based on the PPG blood pressure calculation model;

A display module is configured to display the blood pressure measurement value of the user.

In conjunction with the second aspect, in a first possible implementation of the second aspect, the processor is further configured to:

If the PTT acquisition duration is less than the preset PTT effective duration and the PPG acquisition duration is less than the preset PPG effective duration, the ECG acquisition duration is obtained, where the ECG acquisition duration refers to the signal quality of the ECG signal satisfies the first The length of the preset condition;

If it is determined that the ECG acquisition duration is greater than or equal to a preset ECG effective duration, the blood pressure measurement value of the user is acquired based on the ECG blood pressure calculation model.

With reference to the second aspect, in a second possible implementation manner of the second aspect, when the processor acquires the blood pressure measurement value of the user based on the PPG blood pressure calculation model, specifically:

Collecting data for calculating blood pressure in the PTT blood pressure calculation model;

Calculate the PPG correlation coefficient based on the collected data;

And introducing the PPG correlation coefficient and the collected data into the PTT blood pressure calculation model, and obtaining a model for calculating blood pressure according to the PPG signal characteristic value as the PPG blood pressure calculation model;

The PPG signal characteristic value corresponding to the collected PPG signal is substituted into the PPG blood pressure calculation model, and the blood pressure measurement value of the user is calculated.

With reference to the second aspect or any one of the foregoing possible implementation manners, in a third possible implementation manner of the second aspect, the first preset condition is a lead connection state of the ECG signal a normal connection state and a signal-to-noise ratio of the ECG signal is less than or equal to a first threshold, or a lead connection state of the ECG signal is a normal connection state and invalid feature points in the ECG signal are in a total feature point The ratio is less than or equal to the second threshold, or the lead connection state of the ECG signal is a normal connection state and the ECG signal continuously acquires a vertex position of the ECG R wave.

With reference to the second aspect or any one of the foregoing possible implementation manners, in a fourth possible implementation manner of the second aspect, the second preset condition is that the signal to noise ratio of the PPG signal is less than or It is equal to the third threshold, or the proportion of the invalid feature points in the PPG signal in the total feature points is less than or equal to the fourth threshold.

The beneficial effects of the present invention are as follows: the method of the embodiment of the present invention is used to collect the ECG signal and the PPG signal of the user; and the acquisition time length of the PTT is acquired, and the PTT acquisition duration refers to the signal quality of the ECG signal that satisfies the first preset condition and the signal of the PPG signal. The quality meets the duration of the second preset condition at the same time; if it is determined that the PTT acquisition duration is greater than or equal to the preset PTT effective duration, the user's blood pressure measurement value is obtained based on the PTT blood pressure calculation model; if it is determined that the PTT acquisition duration is less than the preset PTT The effective duration is the length of the PPG acquisition. The PPG acquisition duration refers to the duration of the PPG signal's signal quality that meets the second preset condition. If the PPG acquisition duration is greater than or equal to the preset PPG effective duration, the PPG blood pressure calculation model is used to obtain the user. Blood pressure measurement. Therefore, the method of the embodiment of the present invention can improve the user experience, and the user's blood pressure measurement value can be obtained even if the ECG signal is poorly contacted or the electrode is detached, thereby improving the efficiency of the blood pressure measurement.

DRAWINGS

1 is a flow chart showing an overview of a blood pressure measuring method according to an embodiment of the present invention;

2 is a specific flowchart of user A measuring blood pressure according to an embodiment of the present invention;

3 is a schematic structural view of a blood pressure measuring device according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Embodiments of the present invention provide a method and a device for measuring blood pressure, which are used to overcome the situation in which the electrode is detached and the ECG signal is not acquired, thereby making it impossible to perform blood pressure measurement. The method and the device are based on the same inventive concept. Since the principles of the method and the device for solving the problem are similar, the implementation of the device and the method can be referred to each other, and the repeated description is not repeated.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , an embodiment of the present invention provides a blood pressure measurement method, and the specific process includes:

Step 110: Collect the ECG signal and the PPG signal of the user.

Specifically, it may be a process as follows: the user turns on the blood pressure measuring device, and gives a blood pressure measurement opening instruction, and when the blood pressure measuring device receives the blood pressure measurement opening command, starts collecting the user's ECG signal and the PPG signal;

Alternatively, after the user turns on the blood pressure measurement device, if the blood pressure measurement device determines that the time when the lead connection state of the collected user ECG signal is in the normal connection state exceeds the first duration, the user may be prompted to determine whether to open the blood pressure measurement. If the user chooses to turn on the blood pressure measurement, the blood pressure measuring device starts measuring the user's blood pressure based on the received blood pressure measurement opening command. The first duration here is a preset value, for example 10s.

Specifically, when the length of the lead connection state of the ECG signal is in the normal connection state exceeds t ₁ , the blood pressure measurement can be automatically started. When the duration is less than t ₁ , the blood pressure measurement device may not be automatically caused by the user's accidental collision. Start blood pressure measurement.

Step 120: Obtain a PTT acquisition duration. The PTT acquisition duration refers to a duration in which the signal quality of the ECG signal satisfies the first preset condition and the signal quality of the PPG signal simultaneously satisfies the second preset condition.

Specifically, after the blood pressure measuring device collects the ECG signal and the PPG signal, it is necessary to separately judge the signal quality of the two signals.

When determining the signal quality of the PPG signal, the second preset condition herein may be that the signal to noise ratio of the PPG signal is less than or equal to the third threshold, or the proportion of the invalid feature points in the PPG signal is less than or equal to the total feature point. Equal to the fourth threshold and so on. Specifically, the duration of the PPG signal with the signal-to-noise ratio less than or equal to the third threshold may be used as the PPG acquisition duration, or the duration of the invalid feature point in the PPG signal in the total feature point is less than or equal to the third threshold. As the PPG acquisition duration.

When judging the signal quality of the ECG signal, it is first determined whether the lead connection state of the ECG signal is normal. If the lead is detached, it is directly determined that the ECG signal is unavailable, and if the lead connection state of the ECG signal is the normal connection state, then further Judging the quality of the ECG signal, similarly, the ECG signal can also be used to judge the signal quality. Specifically, the first preset condition herein may be that the lead connection state of the ECG signal is a normal connection state and the signal-to-noise ratio of the ECG signal is less than or equal to the first threshold value as the ECG acquisition duration, or the lead of the ECG signal. The connection state is the normal connection state and the duration of the invalid feature points in the ECG signal in the total feature points is less than or equal to the second threshold as the ECG acquisition duration. In addition, for the ECG signal, the vertex position of the ECG R wave can be continuously acquired as the first preset condition. Among them, the R wave can be identified by a threshold detection method. Therefore, it is also possible to set the lead connection state of the ECG signal to the normal connection state and the ECG signal continuously acquires the duration of the vertex position of the ECG R wave as the ECG acquisition duration.

The method for judging the signal quality is not limited to the above, and various methods for judging the signal quality are provided in the prior art, and details are not described herein again.

Since the PTT needs to be obtained by the ECG signal and the PPG signal acquired synchronously, the signal quality of the ECG signal satisfies the first preset condition and the signal quality of the PPG signal simultaneously satisfies the second preset condition as the PTT acquisition duration.

Specifically, acquiring location information by _ECG R-wave of the ECG signal T, the maximum rising slope value acquired by the PPG signal, troughs, the wave top, dicrotic wave vertex position information or the like according to any one of T _PPG characteristic point, the above-described synchronous acquisition PPT information is obtained after the information, PTTw=t _PPG -t _ECG .

Step 130: If it is determined that the PTT acquisition duration is greater than or equal to the preset PTT effective duration, the user's blood pressure measurement is obtained based on the PTT blood pressure calculation model.

After obtaining the PTT acquisition duration in step 120, the relationship between the PTT acquisition duration and the preset PTT effective duration is further determined. The preset PTT effective duration may be determined according to an empirical value. The so-called PTT effective duration refers to the shortest measurement duration that the user must use the PTT blood pressure calculation model to obtain the blood pressure measurement value, and the signal quality of the ECG signal satisfies the first preset condition and the signal quality of the PPG signal satisfies at the same time. Two preset conditions. Specifically, in each beat cycle of the heart, the effective ECG waveform feature points and the effective PPG waveform feature points can form an effective pair, called an effective PTT pairing period. The PTT effective duration consists of multiple valid PTT pairing periods. Among them, the ECG waveform feature point usually refers to the R wave position, and the PPG waveform feature point usually refers to the position of the valley, the wave top, and the maximum slope point of the rising edge.

When the blood pressure measuring device determines that the PTT acquisition duration is greater than or equal to the preset PTT effective duration, the corresponding PTT result is calculated according to the ECG signal and the PPG signal corresponding to the PTT acquisition duration, and the obtained PTT result is substituted into the PTT blood pressure calculation model. The user's blood pressure measurement is calculated, wherein the PTT blood pressure calculation model can be adopted but not limited to the following formula:

Among them, SBP ₀ is the systolic pressure calibration value, DBP ₀ is the diastolic pressure calibration value, PTT _w0 is the pulse wave propagation time calibration value, PTTw is the current pulse wave propagation time, and A is the preset coefficient, which is related to the elasticity of the blood vessel wall.

It should be noted that the corresponding PTT results can be calculated according to the ECG signal and the PPG signal corresponding to the PTT acquisition duration, and the obtained PTT results are substituted into the PTT blood pressure calculation model to calculate the user's blood pressure measurement values. In addition, after determining that the PTT acquisition duration is greater than or equal to the preset PTT effective duration, the ECG signal and the PPG signal acquired subsequently are determined. When the collected ECG signal satisfies the first preset condition and the PPG signal satisfies the second preset condition, the corresponding PTT is calculated, and the PTT is substituted into the PTT blood pressure calculation model to calculate the user's blood pressure measurement value.

Further, when the corresponding PTT result is calculated according to the ECG signal and the PPG signal corresponding to the PTT acquisition duration, and the obtained PTT result is substituted into the PTT blood pressure calculation model to calculate the blood pressure measurement value of the user, the acquisition time period can be obtained. The plurality of PTTs are averaged, or the PTTs within the preset range are averaged according to the distribution weights of the plurality of PTTs, and then the PTT average is substituted into the PTT blood pressure calculation model.

Or, according to the ECG signal and the PPG signal corresponding to the PTT acquisition duration, the corresponding PTT result is calculated, and the plurality of PTTs are respectively substituted into the PTT blood pressure calculation model to obtain the blood pressure value, and then the obtained plurality of blood pressure values are averaged, or According to the distribution weight of the plurality of blood pressure values, the blood pressure values distributed within the preset range are averaged as the blood pressure measurement value of the user.

For example, suppose the obtained high pressure values are five blood pressure data of 121, 122, 121, 130, and 125, and the average value of the five high pressure values is 123.8. Alternatively, the high pressure values distributed within 80% are averaged, and the high pressure values distributed within 80% are only 121, 122, 121, and 125, and the average value is 122.25.

Step 140: If it is determined that the PTT acquisition duration is less than the preset PTT effective duration, the PPG acquisition duration is obtained, and the PPG acquisition duration refers to the duration of the PPG signal's signal quality meeting the second preset condition.

When the blood pressure measuring device determines that the PTT acquisition duration is less than the preset PTT effective duration, the PPG acquisition duration is further determined, and the PPG acquisition duration refers to the duration when the signal quality of the PPG signal satisfies the second preset condition.

Step 150: If it is determined that the PPG acquisition duration is greater than or equal to the preset PPG effective duration, the blood pressure measurement value of the user is obtained based on the PPG blood pressure calculation model.

After obtaining the PPG acquisition duration in step 140, the relationship between the PPG acquisition duration and the preset PPG effective duration is further determined. The preset PPG effective duration may be determined according to an empirical value. The so-called PPG effective duration refers to the shortest measurement duration that the user must take to obtain the blood pressure measurement value of the PPG blood pressure calculation model, and the signal quality of the PPG signal satisfies the second preset condition during the duration. Specifically, two adjacent, valid PPG waveform feature points constitute a PPG valid period. The effective duration of the PPG consists of multiple valid PPG valid periods. PPG waveform feature points are commonly used for valleys, wave tops, and maximum slope points of rising edges.

When the blood pressure measuring device determines that the PPG acquisition duration is greater than or equal to the preset PPG effective duration, the corresponding PPG signal characteristic value is determined according to the PPG signal collected during the PPG acquisition duration, and the obtained PPG signal characteristic value is substituted into the PPG blood pressure calculation model. User's blood pressure measurement.

Among them, the PPG blood pressure measurement model can be obtained by the following method, but is not limited to the following formula:

First, collect data for calculating blood pressure in the PTT blood pressure calculation model, for example, SBP ₀ (systolic pressure calibration value), DBP ₀ (diastolic pressure calibration value), PTT _w0 (pulse wave propagation time calibration value), and R for collecting ECG. Wave position, R wave amplitude, PPG waveform vertex, PPG waveform bottom point, PPG waveform rising edge slope maximum point, etc.

Second, calculate the PPG correlation coefficient B based on the collected data, wherein the calculation formula of the PPG correlation coefficient B is:

B=PTT _w0 ² /b

(SBP-DBP)=b*(SBP ₀ -DBP ₀ )*H _PPG

b is the proportional coefficient between the difference between the two blood pressures and the height of the PPG waveform. This scale factor needs to be obtained through empirical data accumulation.

Third, the PPG correlation coefficient and the collected data are brought into the PTT blood pressure calculation model, and a model for calculating blood pressure based on the PPG signal characteristic value is obtained as a PPG blood pressure calculation model.

Here, the characteristic value of the PPG signal is H _PPG , that is, the height of the PPG waveform, and the PPG blood pressure calculation model is:

DBP=SBP ₀ /3+2*DBP ₀ /3+(A/2)*ln(H _PPG *PTT _W0 ² /B)-(SBP ₀ -DBP ₀ )*H _PPG *

^{_{PTT W0 2 / (3 * B}} )

SBP=DBP+(SBP ₀ -DBP ₀ )*H _PPG /b

It should be noted that the PPG signal characteristic value corresponding to the PPG acquisition duration can be substituted into the PTT blood pressure calculation model to calculate the user's blood pressure measurement value. In addition, after determining that the PPG acquisition duration is greater than or equal to the preset PPG effective duration, the PPG signal collected subsequently is determined. When the collected PPG signal satisfies the second preset condition, the corresponding PPG signal characteristic value is substituted into the PPG blood pressure calculation model to calculate the user's blood pressure measurement value.

In addition, if the blood pressure measuring device determines that the PTT acquisition duration is less than the preset PTT effective duration and the PPG acquisition duration is less than the preset PPG effective duration, the ECG acquisition duration can be acquired, and the ECG acquisition duration refers to the signal quality of the ECG signal satisfies the first pre- Set the duration of the condition. The blood pressure measuring device acquires the blood pressure measurement value of the user based on the ECG blood pressure calculation model if it is determined that the ECG acquisition duration is greater than or equal to the preset ECG effective duration. The preset ECG effective duration here is determined based on the empirical value. The so-called ECG effective duration refers to the shortest measurement duration that the ECG blood pressure calculation model is to be used to obtain the user's blood pressure measurement value, and the signal quality of the ECG signal satisfies the first preset condition during the duration. Specifically, two adjacent, valid ECG waveform feature points constitute an ECG valid period. The effective duration of the ECG consists of multiple valid ECG valid periods. The ECG waveform feature point usually refers to the R wave position.

Specifically, before the blood pressure measurement is performed on the user according to the ECG signal, the relationship between the SBP and the heart rate variability value, that is, SBP=K _ECG1 *RR, and (SBP+DBP)/2, needs to be established according to information such as age, gender, and weight. The relationship between the heart rate variability and (SBP+DBP)/2=K _ECG2 *RR.

Among them, K _ECG1 and K _ECG2 are the empirical coefficients obtained after a large number of people collect, and RR is the heart rate variability value, which is obtained by calculating and analyzing the ECG signal. K _ECG1 and K _{ECG2 are} determined based on the information provided by the user on age, sex, weight, etc., and the SBP value and the DBP value are further calculated.

When the blood pressure measuring device determines to obtain the blood pressure measurement value of the user based on the ECG blood pressure calculation model, if the signal quality of the PPG signal is improved, and the PTT acquisition time length is greater than or equal to the preset PTT effective time length, then the user is converted into a PTT blood pressure calculation model. Blood pressure measurement value, if the signal quality of the ECG signal is deteriorated, and the signal quality of the PPG signal is improved, and the PPG acquisition duration is greater than or equal to the preset PPG effective duration, then the blood pressure measurement value of the user is obtained based on the PPG blood pressure calculation model.

Since the blood pressure data based on the PPG blood pressure measurement method is higher in accuracy than the blood pressure measurement method based on the ECG, in the embodiment of the present invention, when the blood pressure measurement method based on PTT is not available, the blood pressure measurement based on the PPG can be preferentially considered. the way.

In another scenario, the PTT blood pressure measurement method may be due to poor PPG signal quality. It cannot be performed normally. For example, due to individual skin color, damage to the measurement site, weak perfusion, etc., the quality of the obtained PPG signal is poor, resulting in the inability to perform PPG feature point recognition. In this case, a blood pressure based method based on ECG can be used. Further, in order to improve the quality of the PPG signal, the light intensity can be adjusted. When the PPG signal quality after adjusting the light intensity reaches the requirement, if the PTT acquisition time reaches the preset PTT effective duration, the PTT blood pressure measurement is performed; if the PTT acquisition time is long If the preset PTT effective duration is not reached, and the PPG acquisition duration reaches the preset PPG effective duration, the PPG blood pressure measurement is used; if the PTT acquisition duration and the PPG acquisition duration have not reached the preset value, the ECG measurement mode is continued.

Embodiment 1, taking FIG. 2 as an example, performing blood pressure measurement for user A, specifically:

Step 201: User A initiates blood pressure measurement.

Step 202: The blood pressure measuring device collects the ECG signal and the PPG signal of the user A.

Step 203: The blood pressure measuring device acquires the PTT collection duration, determines whether the PTT acquisition duration is greater than or equal to the preset PTT effective duration, and if yes, executes step 204, otherwise performs step 205.

Step 204: The blood pressure measuring device calculates the blood pressure measurement value of the user A based on the PTT blood pressure calculation model.

Step 205: The blood pressure measuring device acquires the PPG acquisition duration, and determines whether the PPG acquisition duration is greater than or equal to the preset PPG effective duration. If the step 206 is performed, otherwise step 207 is performed.

Step 206: The blood pressure measuring device calculates the blood pressure measurement value of the user A based on the PPG blood pressure calculation model.

Step 207: The blood pressure measuring device acquires the ECG acquisition duration, and determines whether the ECG acquisition duration is greater than or equal to the preset ECG effective duration. If the step 208 is performed, otherwise step 209 is performed.

Step 208: The blood pressure measuring device calculates the blood pressure measurement value of the user A based on the ECG blood pressure calculation model.

Step 209: The blood pressure measuring device prompts the user A to fail the blood pressure measurement.

As shown in FIG. 3, the embodiment of the present invention provides a blood pressure measuring device 30, which may be a watch, a wristband or other wearable device, or a tablet computer, etc., the device includes:

The ECG signal collecting circuit 31 is configured to collect an ECG signal of the user;

The PPG signal collecting circuit 32 is configured to collect a PPG signal of the user;

The processor 33 is configured to acquire a PTT acquisition duration, where the PTT acquisition duration refers to a duration in which the signal quality of the ECG signal satisfies a first preset condition and the signal quality of the PPG signal simultaneously satisfies a second preset condition;

If it is determined that the PTT acquisition duration is greater than or equal to a preset PTT effective duration, acquiring a blood pressure measurement value of the user based on the PTT blood pressure calculation model;

If it is determined that the PTT collection duration is less than the preset PTT effective duration, the PPG acquisition duration is obtained, and the PPG acquisition duration refers to the duration of the PPG signal that meets the second preset condition;

If it is determined that the PPG acquisition duration is greater than or equal to a preset PPG effective duration, obtaining a blood pressure measurement value of the user based on the PPG blood pressure calculation model;

The display module 34 is configured to display a blood pressure measurement value of the user.

Optionally, the processor 33 is further configured to:

If the PTT acquisition duration is less than the preset PTT effective duration and the PPG acquisition duration is less than the preset PPG effective duration, the ECG acquisition duration is obtained, where the ECG acquisition duration is that the signal quality of the ECG signal meets the first preset. The length of the condition;

If it is determined that the ECG acquisition duration is greater than or equal to the preset ECG effective duration, the user's blood pressure measurement is obtained based on the ECG blood pressure calculation model.

Optionally, when the processor 33 acquires the blood pressure measurement value of the user based on the PPG blood pressure calculation model, specifically, the processor 33 can be used to:

Collecting data for calculating blood pressure in the PTT blood pressure calculation model;

Calculate the PPG correlation coefficient based on the collected data;

The PPG correlation coefficient and the collected data are brought into the PTT blood pressure calculation model, and a model for calculating blood pressure based on the PPG signal characteristic value is obtained as a PPG blood pressure calculation model;

The PPG signal characteristic value corresponding to the collected PPG signal is substituted into the PPG blood pressure calculation model to calculate the blood pressure measurement value of the user.

Optionally, the first preset condition is that the lead connection state of the ECG signal is a normal connection state and the signal to noise ratio of the ECG signal is less than or equal to the first threshold, or the lead connection state of the ECG signal is positive. The normally connected state and the proportion of the invalid feature points in the ECG signal in the total feature points is less than or equal to the second threshold, or the lead connection state of the ECG signal is the normal connection state and the ECG signal continuously acquires the vertex position of the ECG R wave .

Optionally, the second preset condition is that the signal to noise ratio of the PPG signal is less than or equal to the third threshold, or the proportion of the invalid feature points in the PPG signal in the total feature points is less than or equal to the fourth threshold.

The processor 33 herein may be a chip, such as a Field-Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), or a combination thereof.

The specific connecting medium between the above components is not limited in the embodiment of the present invention. In the embodiment of the present invention, the ECG signal acquisition circuit 31, the PPG signal acquisition circuit 32, the processor 33, and the display module 34 are connected by a bus 35 in FIG. 3, and the bus is indicated by a thick line in FIG. 3, and between other components. The connection method is only for illustrative purposes and is not limited. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 3, but it does not mean that there is only one bus or one type of bus.

In summary, the method provided by the embodiment of the present invention collects the ECG signal and the PPG signal of the user; obtains the duration of the PTT acquisition, and if it is determined that the PTT acquisition duration is greater than or equal to the preset PTT effective duration, the PTT blood pressure calculation model is acquired. The user's blood pressure measurement value; if it is determined that the PTT acquisition duration is less than the preset PTT effective duration, the PPG acquisition duration is obtained; if it is determined that the PPG acquisition duration is greater than or equal to the preset PPG effective duration, the user's blood pressure measurement is obtained based on the PPG blood pressure calculation model. value. Therefore, the method of the embodiment of the present invention can improve the user experience, and the user's blood pressure measurement value can be obtained even if the ECG signal is poorly contacted or the electrode is detached, thereby improving the efficiency of the blood pressure measurement.

It should be noted that the steps of the method provided in the embodiment of the present invention may be performed in parallel or in series, and some steps may also be implemented in a previous step. For example, the step of acquiring the PPG acquisition time is also performed. It can be obtained during the previous acquisition of the PTT acquisition duration.

The terms "first", "second", etc., as used herein, are used only to distinguish different objects, and do not represent a particular order or a particular relationship of the numerical magnitude of the objects.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

While the preferred embodiment of the invention has been described, it will be understood that Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and

It is apparent that those skilled in the art can make various modifications and variations to the embodiments of the invention without departing from the spirit and scope of the embodiments of the invention. Thus, if these modifications and changes are made to the embodiments of the present invention The type of the invention is intended to be included within the scope of the appended claims and the equivalents thereof.

Claims (10)

1. A blood pressure measuring method, comprising:

   Collecting a user's ECG signal and a photoplethysmographic pulse PPG signal;

   Obtaining a pulse wave transit time PTT acquisition duration, where the PTT acquisition duration refers to a duration in which the signal quality of the ECG signal satisfies a first preset condition and the signal quality of the PPG signal simultaneously satisfies a second preset condition;

   If it is determined that the PTT acquisition duration is greater than or equal to a preset PTT effective duration, acquiring the blood pressure measurement value of the user based on the PTT blood pressure calculation model;

   If it is determined that the PTT acquisition duration is less than the preset PTT effective duration, the PPG acquisition duration is obtained, where the PPG acquisition duration refers to a duration in which the signal quality of the PPG signal meets the second preset condition;

   If it is determined that the PPG acquisition duration is greater than or equal to a preset PPG effective duration, the blood pressure measurement value of the user is obtained based on the PPG blood pressure calculation model.
2. The method of claim 1 further comprising:

   If the PTT acquisition duration is less than the preset PTT effective duration and the PPG acquisition duration is less than the preset PPG effective duration, the ECG acquisition duration is obtained, where the ECG acquisition duration refers to the signal quality of the ECG signal satisfies the first The length of the preset condition;

   If it is determined that the ECG acquisition duration is greater than or equal to a preset ECG effective duration, the blood pressure measurement value of the user is acquired based on the ECG blood pressure calculation model.
3. The method according to claim 1, wherein the obtaining the blood pressure measurement value of the user based on the PPG blood pressure calculation model comprises:

   Collecting data for calculating blood pressure in the PTT blood pressure calculation model;

   Calculate the PPG correlation coefficient based on the collected data;

   And introducing the PPG correlation coefficient and the collected data into the PTT blood pressure calculation model, and obtaining a model for calculating blood pressure according to the PPG signal characteristic value as the PPG blood pressure calculation model;

   The PPG signal characteristic value corresponding to the collected PPG signal is substituted into the PPG blood pressure calculation model, and the blood pressure measurement value of the user is calculated.
4. The method according to any one of claims 1 to 3, wherein the first preset condition is that a lead connection state of the ECG signal is a normal connection state and a signal to noise ratio of the ECG signal is less than or equal to a first threshold, or a lead connection state of the ECG signal is a normal connection state and a ratio of invalid feature points in the ECG signal to a total of feature points is less than or equal to a second threshold, or a guide of the ECG signal The connected state is a normal connected state and the ECG signal continuously acquires a vertex position of the ECG R wave.
5. The method according to any one of claims 1 to 4, wherein the second preset condition is that a signal to noise ratio of the PPG signal is less than or equal to a third threshold, or an invalid feature point in the PPG signal The proportion in the total feature points is less than or equal to the fourth threshold.
6. A blood pressure measuring device, comprising:

   ECG signal acquisition circuit for collecting the ECG signal of the user;

   a PPG signal acquisition circuit for collecting the PPG signal of the user;

   a processor for obtaining a PTT acquisition duration, where the PTT acquisition duration refers to a duration in which the signal quality of the ECG signal satisfies a first preset condition and the signal quality of the PPG signal simultaneously satisfies a second preset condition;

   If it is determined that the PTT acquisition duration is greater than or equal to a preset PTT effective duration, acquiring the blood pressure measurement value of the user based on the PTT blood pressure calculation model;

   If it is determined that the PTT acquisition duration is less than the preset PTT effective duration, the PPG acquisition duration is obtained, where the PPG acquisition duration refers to a duration in which the signal quality of the PPG signal meets the second preset condition;

   If it is determined that the PPG acquisition duration is greater than or equal to a preset PPG effective duration, acquiring the blood pressure measurement value of the user based on the PPG blood pressure calculation model;

   A display module is configured to display the blood pressure measurement value of the user.
7. The device according to claim 6, wherein the processor is further configured to:

   If the PTT acquisition duration is less than the preset PTT effective duration and the PPG acquisition duration is less than the preset PPG effective duration, the ECG acquisition duration is obtained, where the ECG acquisition duration refers to the signal quality of the ECG signal satisfies the first The length of the preset condition;

   If it is determined that the ECG acquisition duration is greater than or equal to a preset ECG effective duration, then based on the ECG The blood pressure calculation model acquires blood pressure measurements of the user.
8. The device according to claim 6, wherein when the processor acquires the blood pressure measurement value of the user based on the PPG blood pressure calculation model, specifically:

   Collecting data for calculating blood pressure in the PTT blood pressure calculation model;

   Calculate the PPG correlation coefficient based on the collected data;

   And introducing the PPG correlation coefficient and the collected data into the PTT blood pressure calculation model, and obtaining a model for calculating blood pressure according to the PPG signal characteristic value as the PPG blood pressure calculation model;

   The PPG signal characteristic value corresponding to the collected PPG signal is substituted into the PPG blood pressure calculation model, and the blood pressure measurement value of the user is calculated.
9. The device according to any one of claims 6 to 8, wherein the first preset condition is that a lead connection state of the ECG signal is a normal connection state and a signal to noise ratio of the ECG signal is less than or equal to a first threshold, or a lead connection state of the ECG signal is a normal connection state and a ratio of invalid feature points in the ECG signal to a total of feature points is less than or equal to a second threshold, or a guide of the ECG signal The connected state is a normal connected state and the ECG signal continuously acquires a vertex position of the ECG R wave.
10. The device according to any one of claims 6 to 9, wherein the second preset condition is that a signal to noise ratio of the PPG signal is less than or equal to a third threshold, or an invalid feature point in the PPG signal The proportion in the total feature points is less than or equal to the fourth threshold.

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