A high-precision rapid non-invasive blood pressure measurement method and device with continuous static pressure change

Abstract

The application relates to a high-precision rapid non-invasive blood pressure measurement method and device with continuous static pressure change. The method is to continuously implement pulse wave measurement, continuously change the static pressure applied to the measurement part during the measurement process, obtain the actually measured pulse wave, extract the characteristic variable for calculating the blood pressure based on the envelope line of the actually measured pulse wave, and obtain the blood pressure measurement result according to the blood pressure calculation model. The measurement device comprises a cuff provided with an air bag, a probe and a host computer. The host computer controls the air bag inflation and deflation device and the probe to realize the blood pressure measurement of the above method. The application can conveniently, rapidly and highly accurately realize blood pressure measurement.

Description

[0001] This application is a divisional application of the following invention patent application: Application date: April 18, 2025, Application number: 202510490993.3, Invention title: A high-precision, rapid, non-invasive blood pressure measurement method and device. Technical Field

[0002] This invention relates to a high-precision, rapid, non-invasive blood pressure measurement method and device with continuous static pressure variation, belonging to the field of non-invasive blood pressure measurement technology. Background Technology

[0003] Blood pressure refers to the lateral pressure exerted by blood on the walls of blood vessels as blood flows through them. It is an important physiological indicator reflecting cardiovascular function and can be combined with other physiological indicators and diagnostic methods to assess related health and disease conditions. It is of great significance in disease diagnosis, observation of treatment effects, prognosis assessment, and health management.

[0004] Existing blood pressure measurement methods can be broadly classified into two categories: invasive direct measurement methods and non-invasive indirect measurement methods. Among these methods, invasive direct measurement provides the most accurate blood pressure data, but it requires advanced techniques and involves some trauma, thus it is only suitable for the resuscitation of critically ill patients and patients undergoing major surgery. Indirect measurement methods, on the other hand, obtain blood pressure indirectly by measuring parameters such as arterial wall pulsation and changes in vascular volume. Due to their simplicity and ease of implementation, indirect measurement methods are widely used in clinical practice.

[0005] Indirect measurement methods can be divided into two main categories: intermittent measurement methods and continuous measurement methods. Among them, continuous blood pressure measurement methods mainly include arterial tension method, volume compensation method, pulse wave velocity or pulse wave transit time measurement method, and pulse wave characteristic parameter determination method, etc.

[0006] The arterial tension method requires the sensor to have high sensitivity to displacement and pressure. The sensor must be pressed firmly against the artery near the bone and the sensor measurement position needs to be kept relatively fixed. When the physiological state of the test subject changes, the measurement error may be caused by the inconsistency between the change in external force and average pressure.

[0007] Volumetric compensation methods can be mainly divided into two categories: measurements based on external pressure applied by a balloon and finger-tip measurements based on photoplethysmography. Using a balloon to measure arterial pressure for continuous blood pressure measurement is simple to use, but the continuous pressure from the balloon can cause venous congestion over time, leading to discomfort for the test subject. Finger-tip blood pressure measurements using photoplethysmography suffer from significant signal interference, instability, and low measurement accuracy. Furthermore, applying a preset reference pressure to the subject for extended periods can cause discomfort and also affect measurement accuracy.

[0008] Compared to arterial tension methods, pulse wave velocity or pulse wave transit time measurement methods have lower sensor positioning requirements and less discomfort. However, establishing a model to measure blood pressure by relating pulse wave velocity or transit time to blood pressure is complex, has significant individual variability, and is quite difficult.

[0009] The pulse wave characteristic parameter measurement method estimates blood pressure by analyzing the characteristic parameters of the pulse wave. To identify different characteristic parameters of the pulse wave, it is necessary to rely on complex signal processing and algorithms, as well as a large amount of data training and validation. Its accuracy and reliability vary among different populations.

[0010] Because these existing technologies have their own unique features, they are suitable for their respective applications and can obtain measurement data with corresponding accuracy, but they also have certain limitations. Therefore, it is necessary to develop a convenient and practical measurement method that can meet the requirements of higher accuracy. Summary of the Invention

[0011] The purpose of this invention is to achieve blood pressure measurement in a convenient, fast and highly accurate manner.

[0012] The technical solution of this invention is: a high-precision, rapid, non-invasive blood pressure measurement method with continuous static pressure variation, which continuously performs pulse wave measurement and applies varying static pressure to the measurement site during the measurement process to obtain the measured pulse wave. Based on the measured pulse wave, feature variables for calculating blood pressure are extracted, and the blood pressure measurement result is calculated according to the blood pressure calculation model.

[0013] The functional expression of a blood pressure calculation model can usually be a linear function, but it can also be a nonlinear function if necessary.

[0014] Preferably, the blood pressure calculation model can be constructed according to the following method:

[0015] i) Pulse wave measurement: Continuously measure the arterial pulse wave. During the measurement, control the static pressure to increase stepwise with a certain jump amplitude to form two or more (including two) static pressure states. Under each static pressure state (static pressure value), measure no less than one pulse wave (complete pulse wave). The maximum static pressure value is preferably lower than the static pressure value that can block blood flow.

[0016] ii) Pulse wave normalization: The pulse wave obtained under one of the static pressure states (e.g., the set maximum static pressure state, or a static pressure state below the maximum static pressure state) is subjected to pulse rate normalization and amplitude normalization operations to form a normalized pulse wave, which is used as the reference pulse wave. The pulse waves obtained under other static pressure states are normalized relative to the reference pulse wave to form a relatively normalized pulse wave.

[0017] For example, a normalized pulse rate and a normalized amplitude are set, the pulse rate of all pulse waves is normalized to the set normalized pulse rate, and the amplitude of the pulse wave used as a reference is normalized to the set normalized amplitude, thereby forming a reference pulse wave; the amplitude of pulse waves not used as a reference is normalized according to the normalization coefficient of the pulse wave used as a reference, wherein the pulse wave used as a reference is the pulse wave at the maximum static pressure value.

[0018] iii) Constructing sample data: Extract the characteristic parameters of the normalized pulse wave, measure the corresponding blood pressure (blood pressure of the same subject), calculate the rate of change of characteristic parameters under adjacent static pressure states, use the rate of change of characteristic parameters as the model input data and blood pressure as the model output data to form a sample data;

[0019] iv) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0020] The characteristic parameters can be any one or more of the following characteristic parameters (including all of them): the change in normalized pulse wave amplitude under different static pressure conditions, the change in the area under the normalized pulse curve, the change in the duration of the rising edge of the normalized pulse wave, and the change in the slope of the rising edge of the normalized pulse wave from the starting point to the maximum amplitude point.

[0021] Preferably, the blood pressure calculation model can be constructed according to the following method:

[0022] i) Pulse wave measurement: Continuously perform photoplethysmography (PPG) measurement. During the measurement process, control the static pressure to increase stepwise with a certain jump amplitude to form two or more (including two) static pressure states. Under each static pressure state (static pressure value), measure no less than one pulse wave (complete pulse wave). The maximum static pressure value is preferably lower than the static pressure value that can block blood flow. The static pressure value in the initial stage is zero.

[0023] ii) Pulse wave normalization: The pulse wave measured under one static pressure state (e.g., the set maximum static pressure state, or a static pressure state below the maximum static pressure) is subjected to pulse rate normalization and amplitude normalization operations to form a normalized pulse wave, which is used as the reference pulse wave. The pulse waves obtained under other static pressure states are normalized relative to the reference pulse wave to form a relatively normalized pulse wave.

[0024] For example, a normalized pulse rate and a normalized amplitude are set, the pulse rate of all pulse waves is normalized to the set normalized pulse rate, and the amplitude of the pulse wave used as a reference is normalized to the set normalized amplitude, thereby forming a reference pulse wave; the amplitude of pulse waves not used as a reference is normalized according to the normalization coefficient of the pulse wave used as a reference, wherein the pulse wave used as a reference is a pulse wave under zero hydrostatic pressure.

[0025] iii) Constructing sample data: Extract the characteristic parameters of the normalized pulse wave, measure the corresponding blood pressure (blood pressure of the same subject), calculate the rate of change of characteristic parameters under adjacent static pressure states, use the rate of change of characteristic parameters as the model input data and blood pressure as the model output data to form a sample data;

[0026] iv) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0027] The characteristic parameters can be any one or more of the following characteristic parameters (including all of them): the amplitude change of the normalized pulse wave under different static pressure conditions, the area change under the normalized pulse curve, the duration of the rising edge of the normalized pulse wave, and the slope change of the rising edge of the normalized pulse wave from the starting point to the maximum amplitude point.

[0028] Preferably, the blood pressure calculation model can be constructed according to the following method:

[0029] i) Pulse wave measurement: Continuously perform arterial pulse wave measurement. During the measurement process, control the static pressure to increase uniformly from zero static pressure to the maximum static pressure (set maximum static pressure) at a certain speed. The maximum static pressure value is preferably lower than the static pressure value that can block blood flow. Several pulse waves are obtained by measurement.

[0030] ii) Constructing the pulse wave envelope curve: Based on the measured pulse waves, construct the pulse wave envelope curve;

[0031] iii) Envelope curve normalization: Perform amplitude normalization operation on the envelope curve to form a normalized envelope curve;

[0032] For example, a normalization amplitude is set, and the envelope curve value (amplitude) corresponding to a certain static pressure (e.g., the set maximum static pressure, or, when appropriate, zero static pressure or a static pressure between zero static pressure and maximum static pressure) is normalized to the set normalization amplitude. The corresponding normalization coefficient is recorded, and the normalization operation is performed on the entire envelope curve using the normalization coefficient to form a normalized envelope curve that varies with static pressure.

[0033] iv) Constructing sample data: Extract the feature parameters of the normalized envelope curve, measure the corresponding blood pressure (blood pressure of the same subject), use the feature parameters as model input data and blood pressure as model output data to form a sample data;

[0034] v) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0035] The characteristic parameter can be any one or more of the following characteristic parameters (including all of them): the slope change of the line connecting the reference point and the maximum static pressure point (the point where the static pressure value is the maximum static pressure value), the amplitude ratio between the maximum static pressure point and the reference point, and the static pressure value of the point where the amplitude is 1 / 2 (one-half) of the amplitude of the maximum static pressure point, wherein the reference point is located between the zero static pressure point and the maximum static pressure point.

[0036] Preferably, the blood pressure calculation model can be constructed according to the following method:

[0037] i) Pulse wave measurement: Continuously perform photoplethysmography (PPG) measurement. During the measurement process, control the static pressure to increase uniformly from zero static pressure to the maximum static pressure (set maximum static pressure value) at a certain rate. The maximum static pressure value is preferably lower than the static pressure value that can block blood flow. Several pulse waves are obtained. Before the static pressure increases uniformly, a segment of zero static pressure pulse wave measurement may or may not be performed. The pulse wave measurement under this segment of zero static pressure is performed continuously with the pulse wave measurement under the uniform increase of static pressure.

[0038] ii) Constructing the pulse wave envelope curve: Based on the measured pulse waves, construct the pulse wave envelope curve;

[0039] iii) Envelope curve normalization: Perform amplitude normalization operation on the envelope curve to form a normalized envelope curve;

[0040] For example, a normalization amplitude is set, and the envelope curve value (amplitude) corresponding to a certain static pressure (e.g., zero static pressure, or, when appropriate, the maximum static pressure or a certain static pressure between zero static pressure and the maximum static pressure) is normalized to the set normalization amplitude. The corresponding normalization coefficient is recorded, and the normalization operation is performed on the entire envelope curve using the normalization coefficient to form a normalized envelope curve that varies with static pressure.

[0041] iv) Constructing sample data: Extract the feature parameters of the normalized envelope curve, measure the corresponding blood pressure (blood pressure of the same subject), use the feature parameters as model input data and blood pressure as model output data to form a sample data;

[0042] v) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0043] The characteristic parameter can be any one or more of the following characteristic parameters (including all of them): the slope of the line connecting the reference point and the maximum static pressure point (the point where the static pressure value is the maximum static pressure value), the amplitude ratio between the maximum static pressure point and the reference point, and the static pressure value at the point where the slope is the largest, wherein the reference point is located between the zero static pressure point and the maximum static pressure point.

[0044] A high-precision, rapid, non-invasive blood pressure measurement device with continuous static pressure variation, capable of performing blood pressure measurement using any of the high-precision, rapid, non-invasive blood pressure measurement methods disclosed in this invention, including:

[0045] A cuff for wearing (e.g., strapped to) the measurement site, having an air bladder for applying static pressure to the measurement site, the air bladder having an inflation / deflation device including an inflation pump for inflation and a deflation valve for controlling deflation.

[0046] A probe (sensor) is used to measure the pulse wave at the site being measured. The probe may be a probe for measuring arterial pulse waves and / or a probe for measuring photoplethysmography (PPG).

[0047] The main unit controls and coordinates the operation of the inflation / deflation device and the probe. It enters the blood pressure measurement working mode according to the blood pressure measurement command input from the outside, controls the probe to continuously collect pulse wave signals, and controls the inflation / deflation device of the air bladder according to the static pressure application requirements to the measured site and the real-time pressure status of the air bladder to achieve the required inflation / deflation action and meet the inflation / deflation requirements. It generates a measured pulse wave based on the pulse wave signal from the probe, extracts the characteristic variables used to calculate blood pressure based on the measured pulse wave, and calculates the blood pressure measurement result according to the blood pressure calculation model.

[0048] Preferably, the probe is a probe for measuring arterial pulse waves. The host controls the inflation and deflation device of the airbag to increase the static pressure in a step-like manner with a certain jump amplitude, forming two or more (including two) static pressure states. Under each static pressure state (static pressure value), at least one measured pulse wave (complete pulse wave) can be obtained (based on the pulse wave signal from the probe). The maximum static pressure value is preferably lower than the static pressure value that can block blood flow, and the static pressure value in the initial stage is greater than zero. The host performs pulse rate normalization and amplitude normalization operations on the pulse wave obtained under one of the static pressure states to form a normalized pulse wave, which is used as the reference pulse wave. The pulse waves obtained under other static pressure states are normalized relative to the reference pulse wave to form relatively normalized normalized pulse waves. The characteristic parameters of the normalized pulse wave are extracted, and the rate of change of characteristic parameters under adjacent static pressure states for blood pressure calculation is calculated. Blood pressure data is calculated based on the blood pressure calculation model and the rate of change of characteristic parameters, which is used as the result of this blood pressure measurement.

[0049] In the above situation, the blood pressure calculation model is preferably obtained using the following method:

[0050] i) Pulse wave measurement: Continuously measure the arterial pulse wave. During the measurement, control the static pressure to increase stepwise with a certain jump amplitude to form two or more (including two) static pressure states. Under each static pressure state (static pressure value), measure no less than one pulse wave (complete pulse wave). The maximum static pressure value is preferably lower than the static pressure value that can block blood flow.

[0051] ii) Pulse wave normalization: The pulse wave measured under one of the static pressure states (e.g., the maximum static pressure state) is subjected to pulse rate normalization and amplitude normalization operations to form a normalized pulse wave, which is used as the reference pulse wave. The pulse waves obtained under other static pressure states are normalized relative to the reference pulse wave to form a relatively normalized pulse wave.

[0052] For example, a normalized pulse rate and a normalized amplitude are set. The pulse rate of all pulse waves is normalized to the set normalized pulse rate, the amplitude of the pulse wave used as a reference is normalized to the set normalized amplitude, and the amplitude of the pulse wave not used as a reference is normalized according to the normalization coefficient of the pulse wave used as a reference. The pulse wave used as a reference is the pulse wave under the maximum static pressure value.

[0053] iii) Constructing sample data: Extract the characteristic parameters of the normalized pulse wave, measure the corresponding blood pressure (blood pressure of the same subject), calculate the rate of change of characteristic parameters under adjacent static pressure states, use the rate of change of characteristic parameters as the model input data and blood pressure as the model output data to form a sample data;

[0054] iv) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0055] The characteristic parameters can be any one or more of the following characteristic parameters (including all of them): the amplitude change of the normalized pulse wave under different static pressure conditions, the area change under the normalized pulse curve, the duration of the rising edge of the normalized pulse wave, and the slope change of the rising edge of the normalized pulse wave from the starting point to the maximum amplitude point.

[0056] Preferably, the probe is a probe for measuring photoplethysmography (PPG). The host controls the inflation and deflation device of the airbag to increase the static pressure in a step-like manner with a certain jump amplitude, forming two or more static pressure states. Under each static pressure state (static pressure value), at least one measured pulse wave (complete pulse wave) can be obtained (based on the pulse wave signal from the probe). The maximum static pressure value is preferably lower than the static pressure value that can block blood flow, and the initial static pressure value is zero. The host performs pulse rate normalization and amplitude normalization operations on the pulse wave obtained under one of the static pressure states to form a normalized pulse wave, which is used as the reference pulse wave. The pulse waves obtained under other static pressure states are normalized relative to the reference pulse wave to form relatively normalized pulse waves. The characteristic parameters of the normalized pulse wave are extracted, and the rate of change of characteristic parameters under adjacent static pressure states for blood pressure calculation is calculated. Blood pressure data is calculated based on the blood pressure calculation model and the rate of change of characteristic parameters, which is used as the result of this blood pressure measurement.

[0057] In the above situation, the blood pressure calculation model is preferably obtained using the following method:

[0058] i) Pulse wave measurement: Continuously perform photoplethysmography pulse wave measurement. During the measurement process, control the static pressure to increase stepwise with a certain jump amplitude to form two or more (including two) static pressure states. Under each static pressure state (static pressure value), measure no less than one pulse wave (complete pulse wave). The maximum static pressure value is preferably lower than the static pressure value that can block blood flow.

[0059] ii) Pulse wave normalization: The pulse rate and amplitude are normalized for the pulse wave measured under one of the static pressure conditions to form a normalized pulse wave, which is used as the reference pulse wave. Pulse waves obtained under other static pressure conditions are normalized relative to the reference pulse wave to form relatively normalized pulse waves;

[0060] For example, a normalized pulse rate and a normalized amplitude are set, the pulse rate of all pulse waves is normalized to the set normalized pulse rate, the amplitude of the pulse wave used as a reference is normalized to the set normalized amplitude, and the amplitude of the pulse wave not used as a reference is normalized according to the normalization coefficient of the pulse wave used as a reference. The pulse wave used as a reference is the pulse wave under zero static pressure.

[0061] iii) Constructing sample data: Extract the characteristic parameters of the normalized pulse wave, measure the corresponding blood pressure (blood pressure of the same subject), calculate the rate of change of characteristic parameters under adjacent static pressure states, use the rate of change of characteristic parameters as the model input data and blood pressure as the model output data to form a sample data;

[0062] iv) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0063] The characteristic parameters can be any one or more of the following characteristic parameters (including all of them): the amplitude change of the normalized pulse wave under different static pressure conditions, the area change under the normalized pulse curve, the duration of the rising edge of the normalized pulse wave, and the slope change of the rising edge of the normalized pulse wave from the starting point to the maximum amplitude point.

[0064] Preferably, the probe is a probe for measuring arterial pulse waves. The host controls the inflation and deflation device of the airbag to increase the static pressure uniformly from zero static pressure to the maximum static pressure at a certain rate. The maximum static pressure value is preferably lower than the static pressure value that can block blood flow. During this process, multiple pulse waves can be formed based on the pulse wave signal from the probe. The host constructs the envelope curve of the pulse wave based on each measured pulse wave. The amplitude of the envelope curve obtained at one static pressure value is normalized. The normalization coefficient obtained therefrom is used to normalize the entire envelope curve to form a normalized envelope curve that varies with static pressure. The characteristic parameters of the normalized envelope curve are extracted. Blood pressure data is calculated based on the blood pressure calculation model and the characteristic parameters, which is used as the result of this blood pressure measurement.

[0065] In the above situation, the blood pressure calculation model is preferably obtained using the following method:

[0066] i) Pulse wave measurement: Continuous measurement of arterial pulse waves is carried out. During the measurement process, the static pressure is controlled to increase uniformly from zero static pressure to the maximum static pressure at a certain speed, and multiple pulse waves are obtained.

[0067] ii) Constructing the pulse wave envelope curve: Based on the measured pulse waves, construct the pulse wave envelope curve;

[0068] iii) Envelope curve normalization: Perform amplitude normalization operation on the envelope curve to form a normalized envelope curve;

[0069] For example, a normalization amplitude is set, and the envelope curve value (amplitude) corresponding to a certain static pressure (e.g., the set maximum static pressure, or, when appropriate, zero static pressure or a static pressure between zero static pressure and maximum static pressure) is normalized to the set normalization amplitude. The corresponding normalization coefficient is recorded, and the normalization operation is performed on the entire envelope curve using the normalization coefficient to form a normalized envelope curve that varies with static pressure.

[0070] iv) Constructing sample data: Extract the feature parameters of the normalized envelope curve, measure the corresponding blood pressure (blood pressure of the same subject), use the feature parameters as model input data and blood pressure as model output data to form a sample data;

[0071] v) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0072] The characteristic parameter can be any one or more of the following characteristic parameters (including all of them): the slope change of the line connecting the reference point and the maximum static pressure point (the point where the static pressure value is the maximum static pressure value), the amplitude ratio between the maximum static pressure point and the reference point, and the static pressure value of the point where the amplitude is 1 / 2 (one-half) of the amplitude of the maximum static pressure point, wherein the reference point is located between the zero static pressure point and the maximum static pressure point.

[0073] Preferably, the probe is a probe for measuring photoplethysmography (PPG). The host controls the inflation and deflation device of the airbag to increase the static pressure uniformly from zero static pressure to the maximum static pressure at a certain rate. The maximum static pressure value is preferably lower than the static pressure value that can block blood flow. During this process, multiple pulse waves can be generated based on the pulse wave signal from the probe. Based on the measured pulse waves, the host constructs the envelope curve of the pulse waves. The amplitude of the envelope curve obtained at one static pressure value is normalized, and the normalization coefficient obtained therefrom is used to normalize the entire envelope curve to form a normalized envelope curve that varies with static pressure. The characteristic parameters of the normalized envelope curve are extracted, and the blood pressure data is calculated based on the blood pressure calculation model and the characteristic parameters, which is used as the result of this blood pressure measurement.

[0074] In the above situation, the blood pressure calculation model is preferably obtained using the following method:

[0075] i) Pulse wave measurement: Continuously perform photoplethysmography pulse wave measurement. During the measurement process, control the static pressure to increase uniformly from zero static pressure to the maximum static pressure at a certain speed. Multiple pulse waves are obtained. Before the static pressure increases uniformly, a segment of zero static pressure pulse wave measurement may or may not be performed. The pulse wave measurement under this segment of zero static pressure is performed continuously with the pulse wave measurement under the uniform increase of static pressure.

[0076] ii) Constructing the pulse wave envelope curve: Based on the measured pulse waves, construct the pulse wave envelope curve;

[0077] iii) Envelope curve normalization: Perform amplitude normalization operation on the envelope curve to form a normalized envelope curve;

[0078] For example, a normalization amplitude is set, and the envelope curve value (amplitude) corresponding to a certain static pressure (e.g., zero static pressure, or, when appropriate, the maximum static pressure or a static pressure between zero static pressure and the maximum static pressure) is normalized to the set normalization amplitude. The corresponding normalization coefficient is recorded, and the normalization operation is performed on the entire envelope curve using the normalization coefficient to form a normalized envelope curve that varies with static pressure.

[0079] iv) Constructing sample data: Extract the feature parameters of the normalized envelope curve, measure the corresponding blood pressure (blood pressure of the same subject), use the feature parameters as model input data and blood pressure as model output data to form a sample data;

[0080] v) Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, fit it with several sample data, and form a blood pressure calculation model.

[0081] The characteristic parameter can be any one or more of the following characteristic parameters (including all of them): the slope of the line connecting the reference point and the maximum static pressure point (the point where the static pressure value is the maximum static pressure value), the amplitude ratio between the maximum static pressure point and the reference point, and the static pressure value at the point where the slope is the largest, wherein the reference point is located between the zero static pressure point and the maximum static pressure point.

[0082] The beneficial effects of this invention are: by constructing a blood pressure calculation model by extracting characteristic parameters of the pulse wave or pulse wave envelope curve, it is beneficial to improve measurement accuracy. Moreover, only a few pulse waves need to be measured to calculate the blood pressure measurement result. The maximum applied static pressure is significantly lower than the static pressure value that can block blood flow. Thus, while ensuring measurement accuracy and precision, it is possible to achieve rapid blood pressure measurement and avoid the discomfort caused to the person being measured by high static pressure. Attached Figure Description

[0083] Figure 1 This is a schematic diagram of the blood pressure measuring device.

[0084] Figure 2 This is a schematic diagram of the static pressure and arterial pulse wave involved in blood pressure measurement based on arterial pulse wave under the static pressure step increase mode;

[0085] Figure 3 This is a schematic diagram of the normalized arterial pulse wave involved in blood pressure measurement based on arterial pulse wave under the static pressure step increase mode. The solid curve is the reference pulse wave P0(t) when the static pressure is SP, and the dashed curve is the relatively normalized pulse wave P1(t) when the static pressure is SP1.

[0086] Figure 4 This is a schematic diagram of the static pressure and arterial pulse waves involved in blood pressure measurement based on photoplethysmography under the static pressure step-increase mode.

[0087] Figure 5 This is a schematic diagram of the normalized photoplethysmography (PPG) involved in blood pressure measurement based on PPG under the static pressure step-increase mode. The dashed curve is the normalized baseline pulse wave P0(t) when the static pressure is zero, and the solid curve is the normalized pulse wave P1(t) when the static pressure increases by Δsp.

[0088] Figure 6 This is a schematic diagram of a photoplethysmography (PPG) wave under constant static pressure.

[0089] Figure 7 This is a schematic diagram of the static pressure and arterial pulse wave involved in blood pressure measurement based on arterial pulse wave under the static pressure uniformly increasing mode. The dashed curve represents static pressure, and the solid curve represents arterial pulse wave.

[0090] Figure 8 This is a schematic diagram of the normalized envelope curve of the arterial pulse wave as a function of static pressure in blood pressure measurement based on the arterial pulse wave under the static pressure constant rate increase mode.

[0091] Figure 9 This is a schematic diagram of the static pressure and arterial pulse wave involved in blood pressure measurement based on photoplethysmography under the static pressure uniform increase mode. The dashed curve represents the static pressure, the solid curve represents the arterial pulse wave, and the vertical dashed line represents the starting moment of the static pressure uniform increase.

[0092] Figure 10 This is a schematic diagram of the normalized envelope curve of the photoplethysmography (PPG) wave as a function of static pressure in blood pressure measurement based on PPG wave under the static pressure constant rate increase mode.

[0093] Figure 11 This is a schematic diagram of a blood pressure measuring device according to the present invention;

[0094] Figure 12 This is a schematic diagram of another blood pressure measuring device according to the present invention;

[0095] Figure 13 This is a schematic diagram of the third type of blood pressure measuring device involved in the present invention;

[0096] Figure 14 This is a schematic diagram of the fourth blood pressure measuring device involved in this invention.

[0097] The markings in the diagram are: 1. External host; 2. Finger cuff; 3. Wrist cuff; 4. Integrated host; 5. Second cuff; 6. Connection cable between probe and host. Detailed Implementation

[0098] See Figure 1This invention can implement any of the blood pressure prediction (or measurement) methods disclosed herein on the basis of a conventional blood pressure monitor or other suitable blood pressure monitor, with the support of corresponding software, as the blood pressure measuring device of this invention. This blood pressure measuring device mainly consists of a cuff (airbag), a probe (e.g., a pressure sensor, or a photoplethysmography probe), an air pump, a pressure relief valve (or venting valve), and a control unit. The control unit is equipped with a signal processing and control module and a human-machine interface (e.g., a display, input buttons, etc.). The cuff is worn (wrapped around) around the arm, wrist, or fingertips, etc. The air pump inflates the airbag, thereby applying pressure (static pressure) to the measuring site. The probe collects the corresponding measurement signal. For example, the pressure sensor can sense the pressure change within the cuff, convert it into an electrical signal, and send it to the control unit for processing to generate an arterial pulse wave; the photoplethysmography probe can sense the volume change at the measuring site caused by the pulse, convert it into an electrical signal, and send it to the control unit for processing to generate a photoplethysmography wave (see [link to relevant documentation]). Figure 6 The deflation valve controls the release of gas from the cuff, adjusting the pressure (reducing pressure). The control unit (signal processing and control module) can control the air pump and deflation valve to achieve the required static pressure and its variation. The display screen shows the measured blood pressure value and other relevant information. The control unit controls and coordinates the operation of each component to ensure the entire measurement process is accurate and stable. The control unit, based on any of the high-precision, rapid, non-invasive blood pressure measurement methods disclosed in this invention, controls the air pump and deflation valve to ensure the static pressure meets the requirements of the measurement process. According to the corresponding measurement method, the probe measures the required pulse wave (pulse wave information / data). Based on the obtained pulse wave, data processing is performed according to the corresponding measurement method to obtain the corresponding processing results, constructing the required blood pressure calculation model or calculating the blood pressure test result based on the blood pressure calculation model.

[0099] Static pressure can be changed by continuously increasing (or decreasing) it at a constant rate, or by increasing (or decreasing) it at a constant amplitude. During the static pressure change according to the set method, continuous pulse wave measurement is performed to obtain the pulse wave under the changing static pressure. Based on the measured pulse wave, blood pressure-related characteristic parameters are extracted, along with accurately measured blood pressure (data from any blood pressure index) under the corresponding state using standard or high-precision instruments. A blood pressure calculation model is then constructed. Based on this model, in actual blood pressure measurement, the same measurement method is used to obtain the measured pulse wave, and the same data processing method is used to obtain the measured characteristic parameters. These measured characteristic parameters are then substituted into the blood pressure calculation model to calculate the blood pressure measurement result.

[0100] The static pressure value can be controlled by controlling the inflation volume.

[0101] A blood pressure calculation model can be obtained by curve fitting based on several sample data. The number of subjects and the selection method can be based on existing technology or relevant regulations.

[0102] The blood pressure (or blood pressure index) to be measured can be any suitable index, such as diastolic pressure or systolic pressure. The static pressure value does not need to reach a level that can block blood flow, and the measurement time is short, which helps to reduce the discomfort of the person being measured.

[0103] Arterial pulse wave and photoplethysmography (PPG) wave can be measured using any suitable existing technique.

[0104] When collecting sample data for constructing a blood pressure calculation model, the subject's blood pressure can be measured using a standard or sufficiently accurate blood pressure measuring instrument, which serves as the subject's blood pressure data. The subject's blood pressure measurement can be performed simultaneously with the subject's pulse wave measurement to ensure consistency between the model input and output data in the sample data. Where appropriate, other methods (measurement method and / or measurement time) can also be used to obtain sufficiently accurate or standard blood pressure data for the subject.

[0105] Example 1. Blood pressure measurement based on arterial pulse wave in static pressure step-increase mode.

[0106] 1. Construct a blood pressure calculation model:

[0107] 1) Pulse wave (arterial pulse wave) measurement:

[0108] like Figure 2 As shown, arterial (pressure) pulse wave (hereinafter referred to as pulse wave) measurement is continuously performed. During the measurement process, the static pressure is controlled to increase in a step-like manner with a certain jump amplitude (usually a constant amplitude increase), forming multiple (e.g., two or three) different (different static pressure values) static pressure states. At least one complete pulse wave is collected at each static pressure value, or multiple pulse waves can be collected.

[0109] The maximum static pressure value (the static pressure value of the last static pressure state) SP (or denoted as SP0) and the static pressure difference between adjacent static pressure states (equal to the magnitude of each static pressure increase / jump) Δsp can be set according to factors such as accuracy requirements and computational convenience. For example, SP can be 60 mmHg and Δsp can be 20 mmHg. Other manually set parameters involved in this invention (including various embodiments) can also be set according to the same principle / method. The starting static pressure value (the static pressure value of the first static pressure state) can be determined based on SP, Δsp, and the selected number of static pressure states (or static pressure jumps).

[0110] When multiple pulse waves are collected under the same static pressure value, the average (arithmetic mean) of the multiple pulse waves can be accumulated and used as the pulse wave under that static pressure value.

[0111] 2) Pulse wave normalization:

[0112] Frequency normalization: The pulse rate of each collected pulse wave is normalized to a standard frequency, such as 75 bpm, to reduce the influence of different heart rates of subjects on model construction and blood pressure measurement results.

[0113] Amplitude normalization: The pulse wave amplitude at maximum static pressure is normalized to a standard amplitude (fixed value A0) to reduce the influence of different blood pressure amplitudes of subjects (or those measured in actual blood pressure measurements) on model construction and blood pressure measurement results. The fixed value A0 can be set according to factors such as accuracy requirements and computational convenience (e.g., roughly similar to the average value of the corresponding index), and the corresponding normalization coefficient can be denoted as k. Amplitude normalization (multiplying by k) is then performed on pulse waves at other static pressures after frequency normalization using the normalization coefficient k.

[0114] After the frequency and amplitude normalization described above, the normalized pulse wave of the corresponding pulse wave is formed. The normalized pulse wave under the maximum static pressure can be used as the reference pulse wave P0(t) for calculation.

[0115] 3) Constructing sample data:

[0116] The characteristic parameters of the normalized pulse wave are extracted. These characteristic parameters are related to blood pressure indicators and can be used to construct a blood pressure calculation model (mathematical model).

[0117] Feature parameters can be selected and extracted using any suitable existing technology or other technologies.

[0118] See Figure 3 In a preferred embodiment, the characteristic parameter may include: the amplitude of the normalized pulse curve (normalized pulse wave). The area under the normalized pulse curve (the curve of a single pulse wave) Normalized pulse wave rise time (duration) The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude (the slope of the line connecting the starting point of the rising edge to the point of maximum amplitude). .

[0119] For the normalized pulse wave (reference pulse wave) P0(t) under the maximum static pressure SP (SP0), calculate the area under the normalized pulse curve. (The origin of the coordinate system can be set as the starting point of the rising edge), normalized pulse wave rising edge time T h_0 The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude. The required feature parameters, etc. The subscript 0 (including T) in the symbols used to represent each feature parameter. h_0In this context, _0) represents the characteristic parameter of the reference pulse wave P0(t).

[0120] For other relative normalized pulse waves under static pressure, such as the normalized pulse wave P1(t) under static pressure SP1 = (SP - Δsp), calculate and obtain the normalized pulse wave amplitude A1 and the area under the normalized pulse curve. Normalized pulse wave rise time T h_1 The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude. etc. The subscript 1 (including T) in the symbols used to describe each characteristic parameter... h_1 In the figure, _1) represents the characteristic parameters required for the normalized pulse wave P1(t), such as the characteristic parameters.

[0121] Generally speaking, for static pressure SP i = (SP-i△sp) normalized pulse wave P i (t), calculate and obtain the normalized pulse wave amplitude A. i (The normalized pulse wave amplitude A0 under maximum static pressure is set during amplitude normalization), the area under the normalized pulse curve. Normalized pulse wave rise time T h_i The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude. And so on, where i = 0, 1, 2, 3, ..., is the static pressure (static pressure state) index, i = 0 corresponds to the maximum static pressure, and the larger the static pressure index, the smaller the static pressure value. The subscript i (including T) in the symbols used to describe each characteristic parameter... h_i In this context, _i) represents the normalized pulse wave P. i The characteristic parameters of (t).

[0122] Calculate the rate of change (variation rate) of pulse wave characteristic parameters under adjacent static pressures (therefore, at least two sets of data at different static pressures are required), and use this as model input (model output data, which can be considered as independent variables). This includes:

[0123] Amplitude change: ;

[0124] Change in area: ;

[0125] Change in pulse wave rise time: ;

[0126] The change in the slope of the rising edge of the pulse wave: .

[0127] When there are only two hydrostatic pressure values ​​(measurement data at only two hydrostatic pressure values), a set of data on the changes in pulse wave characteristic parameters at adjacent hydrostatic pressures can be obtained. When there are only three hydrostatic pressure values, two sets of data on the changes in characteristic parameters at adjacent hydrostatic pressures can be obtained, and so on. When there are multiple sets of changes in characteristic parameters at adjacent hydrostatic pressures, the average value of each change in characteristic parameter can be used as the corresponding change in characteristic parameter for the subject.

[0128] While performing the pulse wave measurement described above, blood pressure can be measured using a precision (standard) blood pressure measuring instrument, and the measured blood pressure (BP value) can be used as the model output data (blood pressure data). When appropriate, accurate or standard blood pressure (BP value) measured by other methods can also be used as the model output data.

[0129] A sample dataset is constructed by combining the corresponding model input data and model output data (model input data and model output data of the same subject).

[0130] 4) Fitting to obtain a blood pressure calculation model:

[0131] The following linear model is used as the mathematical model for calculating blood pressure (BP) (blood pressure calculation model):

[0132]

[0133] Several sample data were collected, and the model coefficients k1, k2, k3, k4 and k5 were fitted by least squares fitting and other methods to establish a blood pressure calculation model.

[0134] Depending on the actual needs, it can also be used only. , , , A portion of it (one or more of its variables) is established solely based on , , , The blood pressure calculation model uses some of the variables in the above data as independent variables. It is understandable that a calculation model including all the above independent variables can obtain more accurate blood pressure calculation results.

[0135] In the blood pressure calculation model, only... , , , When a portion of a variable is used as an independent variable, it is not necessary to calculate the variables (data) that are not used as independent variables.

[0136] The number of subjects used to construct the blood pressure calculation model and their selection can be based on existing technologies to ensure the accuracy, precision, and broad applicability of the blood pressure calculation model.

[0137] 2. Blood pressure measurement

[0138] Based on the same pulse wave measurement and corresponding data processing method as the aforementioned blood pressure calculation model (pulse wave measurement and corresponding data processing method performed on a single subject), pulse waves were measured at static pressures of SP1 = SP - Δsp and SP (if necessary, pulse waves at more static pressure states can also be measured). These pulse waves can be called measured pulse waves. The model independent variables were calculated based on the measured pulse waves. , , and Or a portion thereof, and / or other independent variables (which may be referred to as measured model independent variables, depending on the calculation model used), are substituted into the blood pressure calculation model to obtain blood pressure data, which is then used as the result of this blood pressure measurement.

[0139] During pulse wave measurement, at least one complete pulse wave should be measured at each static pressure value, or two or more, but not too many. Since only a limited number of pulse waves need to be measured in actual blood pressure measurement to obtain the result, the measurement time is short and efficient, and there is no need to apply a high static pressure value to block blood flow, reducing the discomfort of the person being measured.

[0140] Example 2. Blood Pressure Measurement Based on Photoplethysmography in Static Pressure Step-Increasing Mode

[0141] 1. Construct a blood pressure calculation model:

[0142] 1) Pulse wave (photoplethysmography) measurement:

[0143] like Figure 4 As shown, the photoplethysmography (PPG) measurement is continuously performed. During the measurement process, the static pressure is controlled to increase in a step-like manner with a certain jump amplitude (usually with a constant amplitude increase) to form multiple (e.g., two or three) different (different static pressure values) static pressure states. At least one complete pulse wave is collected under each static pressure value, or multiple pulse waves can be collected.

[0144] The static pressure value at the starting point (the first static pressure state) is zero. The static pressure difference between adjacent static pressure states (equal to the magnitude of each static pressure increase / jump) △sp can be set according to factors such as accuracy requirements and calculation convenience. For example, △sp can be 20 mmHg.

[0145] When multiple pulse waves are collected under the same static pressure value, the average (arithmetic mean) of the multiple pulse waves can be accumulated and used as the pulse wave under that static pressure value.

[0146] 2) Pulse wave normalization:

[0147] Frequency normalization: The pulse rate of each collected pulse wave is normalized to a standard frequency, such as 75 bpm, to reduce the influence of different heart rates of subjects on model construction and blood pressure measurement results.

[0148] Amplitude normalization: The amplitude of the pulse wave at zero hydrostatic pressure is normalized to a standard amplitude (fixed value A0) to reduce the influence of different blood pressure amplitudes of subjects (or those measured in actual blood pressure measurements) on model construction and blood pressure measurement results. The fixed value A0 can be set according to factors such as accuracy requirements and computational convenience (e.g., roughly similar to the average value of the corresponding index), and the corresponding normalization coefficient can be denoted as k. Amplitude normalization (multiplying by k) is then performed on pulse waves at other hydrostatic pressures after frequency normalization using the normalization coefficient k.

[0149] After the frequency and amplitude normalization described above, the normalized pulse wave of the corresponding pulse wave is formed. The normalized pulse wave under zero static pressure is used as the reference pulse wave P0(t) for calculation.

[0150] 3) Constructing sample data:

[0151] The characteristic parameters of the normalized pulse wave are extracted. These characteristic parameters are related to blood pressure indicators and can be used to construct a blood pressure calculation model (mathematical model).

[0152] Feature parameters can be selected and extracted using any suitable existing technology or other technologies.

[0153] See Figure 5 In a preferred embodiment, the characteristic parameter may include: the amplitude of the normalized pulse curve (normalized pulse wave). The area under the normalized pulse curve (the curve of a single pulse wave) Normalized pulse wave rise time The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude. .

[0154] For the normalized pulse wave (reference pulse wave) P0(t) under zero hydrostatic pressure, calculate the area under the normalized pulse curve. (The origin of the coordinate system can be set as the starting point of the rising edge), normalized pulse wave rising edge time T h_0 The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude. The required feature parameters, etc. The subscript 0 (including T) in the symbols used to represent each feature parameter. h_0 In this context, _0) represents the characteristic parameter of the reference pulse wave P0(t).

[0155] For normalized pulse waves under other static pressures, such as the normalized pulse wave P1(t) under static pressure SP1=Δsp, calculate and obtain the normalized pulse wave amplitude A1 and the area under the normalized pulse curve. Normalized pulse wave rise time T h_1 The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude. etc. The subscript 1 (including T) in the symbols used to describe each characteristic parameter... h_1 In this context, _1) represents the characteristic parameter of the pulse wave P1(t) normalized relative to the reference pulse wave.

[0156] Generally speaking, for static pressure SP i =i△sp normalized pulse wave P i (t), calculate and obtain the normalized pulse wave amplitude A. i (The normalized pulse wave amplitude A0 under zero static pressure is set during amplitude normalization), the area under the normalized pulse curve. Normalized pulse wave rise time T h_i The slope of the normalized pulse wave rising edge from the starting point to the point of maximum amplitude. And so on, where i = 0, 1, 2, 3, ..., is the static pressure (static pressure state) index, i = 0 corresponds to zero static pressure, and the larger the static pressure index, the larger the static pressure value. The subscript i (including T) in the symbols used to describe each characteristic parameter... h_i In this context, _i) represents the normalized pulse wave P. i The characteristic parameters of (t).

[0157] Calculate the rate of change (variation rate) of pulse wave characteristic parameters under adjacent static pressures (therefore, data from at least two different static pressures are required), and use this as model input (which can be considered as independent variables). This includes:

[0158] Amplitude change: ;

[0159] Change in area: ;

[0160] Change in pulse wave rise time: ;

[0161] The change in the slope of the rising edge of the pulse wave: .

[0162] When there are only two hydrostatic pressure values ​​(measurement data under only two hydrostatic pressure values), a set of data on the changes in pulse wave characteristic parameters under adjacent hydrostatic pressures can be obtained. When there are only three hydrostatic pressure values, two sets of data on the changes in characteristic parameters under adjacent hydrostatic pressures can be obtained, and so on. When there are multiple sets of changes in characteristic parameters under adjacent hydrostatic pressures, the average value of each change in characteristic parameter can be used as the corresponding change in characteristic parameter of the subject.

[0163] While performing the pulse wave measurement described above, blood pressure can be measured using a precision (standard) blood pressure measuring instrument, and the measured blood pressure (BP value) can be used as the model output data (blood pressure data). When appropriate, accurate or standard blood pressure (BP value) measured by other methods can also be used as the model output data.

[0164] A sample dataset is constructed by combining the corresponding model input data and model output data (model input data and model output data of the same subject).

[0165] 4) Fitting to obtain a blood pressure calculation model:

[0166] The following linear model is used as the mathematical model (or blood pressure calculation model) for calculating blood pressure (BP):

[0167]

[0168] Several sample data were collected, and the model coefficients k1, k2, k3, k4 and k5 were fitted by least squares fitting and other methods to establish a blood pressure calculation model.

[0169] Depending on the actual needs, it can also be used only. , , , A portion of it (one or more of its variables) is established solely based on , , , The blood pressure calculation model uses some of the variables in the above data as independent variables. It is understandable that a calculation model including all the above independent variables can obtain more accurate blood pressure calculation results.

[0170] In the blood pressure calculation model, only... , , , When a portion of a variable is used as an independent variable, it is not necessary to calculate the variables (data) that are not used as independent variables.

[0171] The number of subjects used to construct the blood pressure calculation model and their selection can be based on existing technologies to ensure the accuracy, precision, and broad applicability of the blood pressure calculation model.

[0172] 2. Blood pressure measurement

[0173] Based on the same pulse wave measurement and corresponding data processing method as the aforementioned blood pressure calculation model (pulse wave measurement and corresponding data processing method performed on a single subject), pulse waves at zero static pressure and static pressure of SP1=△sp were measured (if necessary, pulse waves at more static pressure states can also be measured). These pulse waves can be called measured pulse waves. The model independent variables are calculated based on the measured pulse waves. , , and Or a portion thereof, and / or other independent variables (which may be referred to as measured model independent variables, depending on the calculation model used), are substituted into the blood pressure calculation model to obtain blood pressure data, which is then used as the result of this blood pressure measurement.

[0174] During pulse wave measurement, at least one complete pulse wave should be measured at each static pressure value, or two or more, but not too many. Since only a limited number of pulse waves need to be measured in actual blood pressure measurement to obtain the result, the measurement time is short and efficient, and there is no need to apply a high static pressure value to block blood flow, reducing the discomfort of the person being measured.

[0175] Example 3. Blood pressure measurement based on arterial pulse wave under static pressure constant rate increase mode

[0176] 1. Construct a blood pressure calculation model:

[0177] 1) Pulse wave (arterial pulse wave) measurement:

[0178] like Figure 7 As shown, arterial (pressure) pulse wave (hereinafter referred to as pulse wave) measurement is continuously performed. During the measurement process, the static pressure is controlled to increase uniformly from the starting static pressure to the maximum static pressure SPm at a certain rate (time change rate), obtaining multiple (e.g., 4, 5, 6, 7 or 8) pulse waves. The starting static pressure is zero (zero static pressure), and the ending static pressure can be recorded as SPm (mmHg).

[0179] The rate of increase in static pressure and the maximum static pressure value SPm can be set according to factors such as accuracy requirements and computational convenience, so that when the static pressure value increases from zero to SPm, the required number of pulse waves (e.g., 4, 5, 6, 7, or 8) can be measured. For example, SPm can be set to 60 mmHg.

[0180] 2) Construct the pulse wave envelope curve

[0181] Based on the measured pulse waves (all pulse waves measured during the process of static pressure increasing uniformly from the initial static pressure to the maximum static pressure SPm), the envelope curve of the pulse waves varying with static pressure is calculated (this can be called the pulse wave envelope curve, or simply the envelope curve). The pulse wave envelope curve can be either the pulse amplitude envelope curve or the pulse area envelope curve. The pulse amplitude envelope curve can be obtained based on the amplitude values ​​of the rising and falling edges of each pulse wave using an appropriate calculation method; the pulse area envelope curve is obtained based on the area of ​​the pulse curve calculated through numerical integration using an appropriate calculation method.

[0182] 3) Envelope curve normalization:

[0183] The pulse wave envelope curve is normalized in amplitude so that its value is Am when the static pressure is at its maximum value SPm. Am can be set according to factors such as computational convenience, and the corresponding normalization coefficient can be denoted as k. When the horizontal axis of the coordinate system used for the pulse wave and envelope curve represents static pressure, the envelope curve value is the variable value represented by the vertical axis, which, for ease of description, can be simply referred to as amplitude, denoted by the symbol A.

[0184] 4) Constructing sample data:

[0185] Extract the characteristic parameters of the normalized envelope curve related to blood pressure. These characteristic parameters are related to blood pressure indicators and can be used to construct a blood pressure calculation model (mathematical model) as model input (model output data, which can be regarded as independent variables).

[0186] Feature parameters can be selected and extracted using any suitable existing technology or other technologies.

[0187] See Figure 8 In a preferred embodiment, the characteristic parameter may include: the slope change when the static pressure value is SP1 (the rate of change of amplitude between the point where the static pressure value is the maximum static pressure value and the point where the static pressure value is SP1). The amplitude change ratio when the static pressure value is SP1 (the amplitude ratio of the point where the static pressure value is the maximum static pressure value to the point where the static pressure value is SP1). The envelope curve value (amplitude) is A m Static pressure value at / 2 ,in A1 is the envelope curve value when the static pressure is SP1. Δsp is set according to actual needs, for example, it can be 20 mmHg. When setting SP1 (or Δsp), the accuracy of the measurement results, as well as the convenience and accessibility of the calculation, should be considered.

[0188] While performing the pulse wave measurement described above, blood pressure can be measured using a precision (standard) blood pressure measuring instrument, and the measured blood pressure (BP value) can be used as the model output data (blood pressure data). When appropriate, accurate or standard blood pressure (BP value) measured by other methods can also be used as the model output data.

[0189] A sample dataset is constructed by combining the corresponding model input data and model output data (model input data and model output data of the same subject).

[0190] 5) Fitting to obtain the blood pressure calculation model:

[0191] The following linear model is used as the mathematical model for calculating blood pressure (BP) (blood pressure calculation model):

[0192]

[0193] Several sample data were collected, and the model coefficients k1, k2, k3 and k4 were fitted by least squares fitting and other methods to establish a blood pressure calculation model.

[0194] Depending on the actual needs, only △K, R, and A portion of the data (one or more of its variables) is used to establish a system containing only ΔK, R, and... The blood pressure calculation model uses some of the variables in the above data as independent variables. It is understandable that a calculation model including all the above independent variables can obtain more accurate blood pressure calculation results.

[0195] In the blood pressure calculation model, only ΔK, R, When a portion of a variable is used as an independent variable, it is not necessary to calculate the variables (data) that are not used as independent variables.

[0196] The number of subjects used to construct the blood pressure calculation model and their selection can be based on existing technologies to ensure the accuracy, precision, and broad applicability of the blood pressure calculation model.

[0197] 2. Blood pressure measurement

[0198] Based on the same pulse wave measurement and corresponding data processing method used in constructing the blood pressure calculation model (pulse wave measurement and corresponding data processing method performed on a single subject), pulse waves were measured from the initial static pressure (zero static pressure) to the maximum static pressure value SPm. These pulse waves can be called measured pulse waves. The model independent variables (ΔK, R, and ...) are calculated based on the measured pulse waves. Or a portion thereof, and / or other independent variables (which may be referred to as measured model independent variables, depending on the calculation model used), are substituted into the blood pressure calculation model to obtain blood pressure data, which is then used as the result of this blood pressure measurement.

[0199] Since blood pressure measurement only requires measuring a limited number of pulse waves, the measurement time is short and the efficiency is high. Furthermore, it does not require applying a high static pressure value to block blood flow, thus reducing the discomfort of the person being measured.

[0200] Example 4. Blood pressure measurement based on photoplethysmography pulses under static pressure uniform increase mode.

[0201] 1. Construct a blood pressure calculation model:

[0202] 1) Pulse wave (photoplethysmography) measurement:

[0203] like Figure 9 As shown, a photoplethysmography (PPG) measurement is continuously performed. During the measurement, the static pressure is controlled to increase uniformly from the initial static pressure to the maximum static pressure SPm at a certain rate (time change rate), obtaining multiple (e.g., 4, 5, 6, 7, or 8) pulse waves. The initial static pressure is zero (zero static pressure), and the final static pressure can be recorded as SPm (mmHg).

[0204] A pulse wave measurement at zero static pressure can be performed before the static pressure increases at a constant rate. This pulse wave measurement at zero static pressure is performed continuously with the pulse wave measurement under constant static pressure increase to improve the stability and accuracy of the measurement data. In the corresponding calculations, the starting moment of the constant static pressure increase can be regarded as the origin of time (t=0) for ease of calculation.

[0205] 2) Construct the pulse wave envelope curve

[0206] Based on the measured pulse waves (all pulse waves measured during the process of static pressure increasing uniformly from the initial static pressure to the maximum static pressure SPm), the envelope curve of the pulse waves varying with static pressure is calculated (this can be called the pulse wave envelope curve, or simply the envelope curve). The pulse wave envelope curve can be either the pulse amplitude envelope curve or the pulse area envelope curve. The pulse amplitude envelope curve can be obtained based on the amplitude values ​​of the rising and falling edges of each pulse wave using an appropriate calculation method; the pulse area envelope curve is obtained based on the area of ​​the pulse curve calculated through numerical integration using an appropriate calculation method.

[0207] 3) Envelope curve normalization:

[0208] The pulse wave envelope curve is normalized in amplitude so that its value is Am when the static pressure is at its maximum value SPm. Am can be set according to factors such as computational convenience, and the corresponding normalization coefficient can be denoted as k. When the horizontal axis of the coordinate system used for the pulse wave and envelope curve represents static pressure, the envelope curve value is the variable value represented by the vertical axis, which, for ease of description, can be simply referred to as amplitude, denoted by the symbol A.

[0209] 4) Constructing sample data:

[0210] Extract the characteristic parameters of the normalized envelope curve related to blood pressure. These characteristic parameters are related to blood pressure indicators and can be used to construct a blood pressure calculation model (mathematical model) as model input (model output data, which can be regarded as independent variables).

[0211] Feature parameters can be selected and extracted using any suitable existing technology or other technologies.

[0212] See Figure 10 In a preferred embodiment, the characteristic parameter may include: the slope change when the static pressure value is SP1 (the rate of change of amplitude between the point where the static pressure value is the maximum static pressure value and the point where the static pressure value is SP1). The amplitude change ratio when the static pressure value is SP1 (the amplitude ratio of the point where the static pressure value is the maximum static pressure value to the point where the static pressure value is SP1). The static pressure value SP at the point with the largest slope on the envelope curve km ,in A1 is the envelope curve value when the static pressure is SP1. Δsp is set according to actual needs, for example, it can be 20 mmHg. When setting SP1 (or Δsp), the accuracy of the measurement results, as well as the convenience and accessibility of the calculation, should be considered.

[0213] While performing the pulse wave measurement described above, blood pressure can be measured using a precision (standard) blood pressure measuring instrument, and the measured blood pressure (BP value) can be used as the model output data (blood pressure data). When appropriate, accurate or standard blood pressure (BP value) measured by other methods can also be used as the model output data.

[0214] A sample dataset is constructed by combining the corresponding model input data and model output data (model input data and model output data of the same subject).

[0215] 5) Fitting to obtain the blood pressure calculation model:

[0216] The following linear model is used as the mathematical model for calculating blood pressure (BP) (blood pressure calculation model):

[0217]

[0218] Several sample data were collected, and the model coefficients k1, k2, k3 and k4 were fitted by least squares fitting and other methods to establish a blood pressure calculation model.

[0219] Depending on the actual needs, only △K, R, and SP can be used. km A portion of the data (one or more of its variables) is used to establish a system containing only ΔK, R, and SP. km The blood pressure calculation model uses some of the variables in the above data as independent variables. It is understandable that a calculation model including all the above independent variables can obtain more accurate blood pressure calculation results.

[0220] In the blood pressure calculation model, only ΔK, R, and SP are used. km When a portion of a variable is used as an independent variable, it is not necessary to calculate the variables (data) that are not used as independent variables.

[0221] The number of subjects used to construct the blood pressure calculation model and their selection can be based on existing technologies to ensure the accuracy, precision, and broad applicability of the blood pressure calculation model.

[0222] 2. Blood pressure measurement

[0223] Based on the same pulse wave measurement and corresponding data processing method used in constructing the blood pressure calculation model (pulse wave measurement and corresponding data processing method performed on a single subject), pulse waves were measured from the initial static pressure (zero static pressure) to the maximum static pressure value SPm. These pulse waves can be called measured pulse waves. The model independent variables (ΔK, R, SP) were calculated based on the measured pulse waves. km Or a portion thereof, and / or other independent variables (which may be referred to as measured model independent variables, depending on the calculation model used), are substituted into the blood pressure calculation model to obtain blood pressure data, which is then used as the result of this blood pressure measurement.

[0224] Since blood pressure measurement only requires measuring a limited number of pulse waves, the measurement time is short and the efficiency is high. Furthermore, it does not require applying a high static pressure value to block blood flow, thus reducing the discomfort of the person being measured.

[0225] See Figures 11-14 This invention allows for continuous, non-invasive blood pressure measurement using any of the blood pressure measurement methods disclosed herein, building upon existing arterial pulse wave sphygmomanometers or photoplethysmography (PPG) sphygmomanometers. The blood pressure measuring device can be divided into or configured with two measurement modes: a precise measurement mode and a rapid measurement mode. The precise measurement mode employs a relatively long inflation / measurement time and a relatively high maximum static pressure value to obtain a relatively large number of pulse waves or a more complete / higher-precision envelope curve, thereby acquiring characteristic parameters with higher accuracy. The rapid measurement mode, on the other hand, can measure blood pressure without requiring a large static pressure value or a long inflation time.

[0226] It can be worn on a suitable measurement site on the body, such as the fingertips, fingertips, wrist, or arm. The cuff and air bladder within the cuff can be selected / designed according to the specific measurement site.

[0227] Figure 11 The measuring device shown is used for blood pressure measurement at the fingertip. It includes an external main unit 1 and a fingertip cuff 2 equipped with an air bladder. The external main unit provides control, signal processing, and display functions. The fingertip cuff secures the air bladder at the measurement site. Static pressure is applied by inflating the air bladder, and arterial pulse waves are collected by a probe, enabling accurate and rapid blood pressure measurement. A photoelectric PPG probe (which can be transmissive or reflective) can be installed on the cuff 2 to detect / collect photoelectric pulse waves. Alternatively, a combined probe capable of measuring both photoplethysmography (PPG) and arterial pulse waves can be installed on the cuff (e.g., an integrated PPG probe and an arterial pulse wave probe, or separate probes on the cuff), simultaneously collecting both arterial and photoelectric pulse waves for accurate and rapid blood pressure measurement.

[0228] Figure 12 and Figure 13 The measuring device shown is used for measuring blood pressure at the wrist (or arm). Figure 12 The illustrated embodiments are like Figure 11 The external host 1 is configured as shown in the embodiment. Figure 13 The illustrated embodiment integrates the main unit 4 with the cuff, a configuration that can be termed an integrated main unit. The main unit (external or integrated) performs control, signal processing, and display functions. The wrist cuff 3 is equipped with an air bladder and a probe to fix the air bladder at the measurement site. Static pressure is applied by inflating the air bladder, and arterial pulse waves are collected by the probe, enabling accurate and rapid blood pressure measurement. A photoelectric PPG probe (e.g., a reflective probe) can be mounted on the wrist cuff 3 to detect / collect photoelectric pulse waves. Alternatively, a combined probe capable of measuring both photoplethysmography (PPG) and arterial pulse waves (e.g., an integrated / combined PPG probe and arterial pulse wave probe, or separate probes on the cuff) can be mounted on the wrist cuff 3, simultaneously collecting both arterial and photoelectric pulse waves for accurate and rapid blood pressure measurement.

[0229] Figure 14 The measuring device shown has a first cuff and a second cuff, wherein the first cuff is a wrist cuff 3 and the second cuff 6 is a fingertip cuff, which can be worn on the wrist (or arm) and fingers respectively. The specific wearing and measurement methods are as follows. Figure 11 The illustrated embodiments and Figure 12 , Figure 13The illustrated embodiment is the same. The host unit used can be an external host unit 1 or an integrated host unit 4 installed on the wrist cuff, used to realize control, signal processing and display functions. The output of the probe on the cuff can be connected to the host unit (e.g., the integrated host unit 4) through the connection cable (e.g., the corresponding data cable) 6 between the probe and the host unit.

[0230] Unless otherwise specified, the preferred and optional technical means disclosed in this invention can be arbitrarily combined to form several different specific embodiments when one preferred or optional technical means is a further limitation of another technical means.

Claims

1. A high-precision, rapid, non-invasive blood pressure measurement method with continuous static pressure variation, comprising continuously performing pulse wave measurement and applying varying static pressure to the measurement site during the measurement process to obtain a measured pulse wave, extracting pulse wave feature variables for calculating blood pressure based on the measured pulse wave, and calculating the blood pressure measurement result according to a blood pressure calculation model, wherein the input of the blood pressure calculation model is the aforementioned pulse wave feature variables. Its features are, The blood pressure calculation model is constructed according to the following method: Pulse wave measurement: Arterial pulse wave measurement is performed continuously. During the measurement process, the static pressure is controlled to increase uniformly from zero static pressure to the maximum static pressure at a certain speed, and several pulse waves are obtained. Constructing the pulse wave envelope curve: Based on the measured pulse waves, construct the pulse wave envelope curve; Envelope curve normalization: Perform amplitude normalization operation on the envelope curve to form a normalized envelope curve; Constructing sample data: Extract the feature parameters of the normalized envelope curve, measure the corresponding blood pressure, use the feature parameters as model input data and blood pressure as model output data to form a sample data; Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, and fit it using several sample data to form a blood pressure calculation model.

2. The high-precision, rapid, non-invasive blood pressure measurement method as described in claim 1, characterized in that, Set a normalization amplitude, normalize the envelope curve value corresponding to a certain static pressure to the set normalization amplitude, record the corresponding normalization coefficient, and use the normalization coefficient to perform normalization operation on the entire envelope curve to form a normalized envelope curve that varies with static pressure.

3. The high-precision, rapid, non-invasive blood pressure measurement method as described in claim 1, characterized in that, The characteristic parameter is any one or more of the following: the slope change of the line connecting the reference point and the maximum static pressure point, the amplitude ratio of the maximum static pressure point to the reference point, and the static pressure value of a point whose amplitude is half that of the maximum static pressure point, wherein the reference point is located between the zero static pressure point and the maximum static pressure point.

4. The high-precision, rapid, non-invasive blood pressure measurement method as described in claim 1, characterized in that, The blood pressure calculation model is a linear model.

5. A high-precision, rapid, non-invasive blood pressure measurement method with continuous static pressure variation, comprising continuously performing pulse wave measurement and applying varying static pressure to the measurement site during the measurement process to obtain a measured pulse wave, extracting pulse wave feature variables for calculating blood pressure based on the measured pulse wave, and calculating the blood pressure measurement result according to a blood pressure calculation model, wherein the input of the blood pressure calculation model is the aforementioned pulse wave feature variables. Its features are, The blood pressure calculation model is constructed according to the following method: Pulse wave measurement: Continuous measurement of photoplethysmography pulse wave is carried out. During the measurement process, the static pressure is controlled to increase uniformly from zero static pressure to the maximum static pressure at a certain speed. Several pulse waves are obtained. Before the static pressure increases uniformly, a pulse wave measurement at zero static pressure can be carried out or not. The pulse wave measurement at zero static pressure is carried out continuously with the pulse wave measurement at uniform static pressure. Constructing the pulse wave envelope curve: Based on the measured pulse waves, construct the pulse wave envelope curve; Envelope curve normalization: Perform amplitude normalization operation on the envelope curve to form a normalized envelope curve; Constructing sample data: Extract the feature parameters of the normalized envelope curve, measure the corresponding blood pressure, use the feature parameters as model input data and blood pressure as model output data to form a sample data; Constructing a blood pressure calculation model: Select a functional expression for the blood pressure calculation model, and fit it using several sample data to form a blood pressure calculation model.

6. The high-precision, rapid, non-invasive blood pressure measurement method as described in claim 5, characterized in that, Set a normalization amplitude, normalize the envelope curve value corresponding to a certain static pressure to the set normalization amplitude, record the corresponding normalization coefficient, and use the normalization coefficient to perform normalization operation on the entire envelope curve to form a normalized envelope curve that varies with static pressure.

7. The high-precision, rapid, non-invasive blood pressure measurement method as described in claim 5, characterized in that, The characteristic parameter is any one or more of the following: the slope of the line connecting the reference point and the maximum static pressure point, the amplitude ratio between the maximum static pressure point and the reference point, and the static pressure value at the point with the largest slope, wherein the reference point is located between the zero static pressure point and the maximum static pressure point.

8. The high-precision, rapid, non-invasive blood pressure measurement method as described in claim 5, characterized in that, The blood pressure calculation model is a linear model.

9. A high-precision, rapid, non-invasive blood pressure measurement device with continuous static pressure variation, comprising: A cuff for wearing on the part being measured, and an air bladder for applying static pressure to the part being measured. The air bladder is equipped with an inflation / deflation device, which includes an inflation pump for inflation and a deflation valve for controlling deflation. A probe used to measure the pulse wave at the site being measured; The main unit controls and coordinates the operation of the inflation / deflation device and the probe. Based on externally inputted blood pressure measurement commands, it enters the blood pressure measurement mode, controls the probe to continuously acquire pulse wave signals, and controls the inflation / deflation of the air bladder based on the required static pressure applied to the measured site and the real-time pressure status of the air bladder. It generates a measured pulse wave based on the pulse wave signals from the probe, extracts pulse wave characteristic variables for calculating blood pressure from the measured pulse wave, and calculates the blood pressure measurement result according to the blood pressure calculation model. The input to the blood pressure calculation model is the aforementioned pulse wave characteristic variables. Its features are, The probe is used to measure arterial pulse waves. The host controls the inflation and deflation device of the airbag to increase the static pressure uniformly from zero static pressure to the maximum static pressure at a certain rate. During this process, multiple pulse waves can be generated based on the pulse wave signal from the probe. The host constructs the envelope curve of the pulse wave based on the measured pulse waves. The amplitude of the envelope curve obtained at one static pressure value is normalized. The normalization coefficient obtained is used to normalize the entire envelope curve to form a normalized envelope curve that varies with static pressure. The characteristic parameters of the normalized envelope curve are extracted. Blood pressure data is calculated based on the blood pressure calculation model and the characteristic parameters, which is used as the result of this blood pressure measurement.

10. A high-precision, rapid, non-invasive blood pressure measurement device with continuous static pressure variation, comprising: A cuff for wearing on the part being measured, and an air bladder for applying static pressure to the part being measured. The air bladder is equipped with an inflation / deflation device, which includes an inflation pump for inflation and a deflation valve for controlling deflation. A probe used to measure the pulse wave at the site being measured; The main unit controls and coordinates the operation of the inflation / deflation device and the probe. Based on externally inputted blood pressure measurement commands, it enters the blood pressure measurement mode, controls the probe to continuously acquire pulse wave signals, and controls the inflation / deflation of the air bladder based on the required static pressure applied to the measured site and the real-time pressure status of the air bladder. It generates a measured pulse wave based on the pulse wave signals from the probe, extracts pulse wave characteristic variables for calculating blood pressure from the measured pulse wave, and calculates the blood pressure measurement result according to the blood pressure calculation model. The input to the blood pressure calculation model is the aforementioned pulse wave characteristic variables. Its features are, The probe is used to measure photoplethysmography (PPG). The host controls the inflation and deflation of the airbag to increase the static pressure uniformly from zero to the maximum static pressure at a certain rate. During this process, multiple pulse waves can be generated based on the pulse wave signal from the probe. Based on the measured pulse waves, the host constructs the envelope curve of the pulse waves. The amplitude of the envelope curve obtained at one static pressure value is normalized, and the normalization coefficient obtained is used to normalize the entire envelope curve to form a normalized envelope curve that varies with static pressure. The characteristic parameters of the normalized envelope curve are extracted, and the blood pressure data is calculated based on the blood pressure calculation model and the characteristic parameters. This data is used as the result of this blood pressure measurement.

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