Wearable non-invasive continuous blood pressure monitoring device and method

Abstract

The present disclosure provides a wearable non-invasive continuous blood pressure monitoring device and method, which can be applied to the field of continuous blood pressure measurement technology. The device includes: a wearable sensor, which is worn on the target part of the target object so as to collect the pulse wave signal of the target object; a controller, which is used to: in response to the blood pressure measurement instruction, control the wearable sensor to apply pressure to the target object, and simultaneously receive the pulse wave signal from the wearable sensor until the pressure meets the first predetermined condition, and generate a pulse wave oscillation curve, the pulse wave oscillation curve including N pulse pulses composed of the pulse wave signal; determine the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information; generate a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve according to the amplitude information of each of the multiple pulse pulses and the time information corresponding to the amplitude information; generate continuous pulsating blood pressure information corresponding to the N pulse pulses according to the amplitude information of the pulse wave oscillation curve envelope.

Description

Technical Field

[0001] The present disclosure relates to the technical field of continuous blood pressure measurement, and in particular to a wearable non-invasive continuous blood pressure monitoring device and method. Background Art

[0002] As one of the key vital signs in the human cardiovascular system, blood pressure can not only effectively reflect the heart's pumping function, the speed of blood flow, and the resistance of peripheral blood vessels, but also is an important indicator in medicine. Non-optimal blood pressure remains a major risk factor for the global disease burden. On the one hand, high blood pressure can lead to cerebrovascular disease, coronary artery disease, heart disease, stroke, kidney disease, and other diseases. At the same time, high blood pressure is also the most common preventable risk factor for cardiovascular disease. Proper blood pressure control has been shown to significantly reduce cardiovascular morbidity and all-cause mortality associated with hypertension. Therefore, regular and accurate measurement of blood pressure is essential for the successful prevention and treatment of hypertension. On the other hand, low blood pressure can lead to insufficient oxygen supply to the body's organs, especially during clinical operations, where persistent low blood pressure can lead to complications such as stroke, acute kidney injury, and myocardial infarction. Therefore, continuous and accurate blood pressure monitoring is essential for preventing cardiovascular disease, monitoring the condition of clinical patients, and guiding drug treatment.

[0003] Based on this, clinical blood pressure measurement methods can be divided into invasive methods and non-invasive methods. The invasive method is to directly measure blood pressure by inserting various catheters or monitoring probes into the heart or blood vessel cavity at locations such as the radial artery or femoral artery. Although this method has its application value in clinical practice, its use is subject to many restrictions in clinical practice because it requires professionals to operate and may bring infection risks and other serious complications to patients, such as thrombosis, embolism, bleeding, infection, or necrosis of distal limbs. For example, a non-invasive method can be an intermittent cuff sphygmomanometer based on auscultation or oscillometric methods. This intermittent measurement method usually only provides instantaneous blood pressure readings and cannot continuously track changes in blood pressure, resulting in a monitoring blind spot. Summary of the invention

[0004] In view of the above problems, the present disclosure provides a wearable non-invasive continuous blood pressure monitoring device and method.

[0005] According to one aspect of the present disclosure, a wearable non-invasive continuous blood pressure monitoring device is provided, comprising: a wearable sensor, worn on a target part of a target object so as to collect a pulse wave signal of the target object; a controller, used to: in response to a blood pressure measurement instruction, control the wearable sensor to apply pressure to the target object, and simultaneously receive the pulse wave signal from the wearable sensor until the pressure satisfies a first predetermined condition, and generate a pulse wave oscillation curve, wherein the pulse wave oscillation curve comprises N pulse pulses constituted by the pulse wave signal, and N is a positive integer greater than 1; determine amplitude information of each of the N pulse pulses and time information corresponding to the amplitude information; generate a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve according to the amplitude information of each of the multiple pulse pulses and the time information corresponding to the amplitude information; generate continuous pulsating blood pressure information corresponding to the N pulse pulses according to the amplitude information of the pulse wave oscillation curve envelope.

[0006] According to an embodiment of the present disclosure, the controller includes a control module, a motor drive module, a motor, a pressure sensor and a syringe, and the wearable sensor includes a liquid capsule; the control module is used to send a control signal to the motor drive module in response to a blood pressure measurement instruction; the motor drive module is used to output a drive pulse corresponding to the control signal to the motor; the motor is connected to a screw nut arranged in a piston of the syringe through a screw, and the injection head of the syringe is located inside the liquid capsule; the motor is used to rotate the screw according to the drive pulse to control the extension and retraction of the screw nut, thereby driving the piston to move, so as to adjust the liquid volume inside the liquid capsule by changing the liquid volume inside the syringe, thereby controlling the pressure applied by the liquid capsule to the target object.

[0007] According to an embodiment of the present disclosure, the controller also includes a limit switch; wherein, when the piston is in the target position, the limit switch is closed so as to send a limit signal to the control module via a closed loop corresponding to the limit switch, so that the control module stops sending the control signal to the motor drive module; when the piston is not in the target position, the limit switch is disconnected, and when the limit switch is disconnected, the control module is also used to count the drive pulses, generate pulse quantity information, and determine that the pressure satisfies the first predetermined condition when the pulse quantity information satisfies the second predetermined condition.

[0008] According to an embodiment of the present disclosure, the controller also includes a pressure sensor and an analog-to-digital converter; the first end of the pressure sensor is connected to the liquid bag, and is used to collect information on the pressure applied by the liquid bag to the target object, and the collected pressure information is in the form of an analog signal; the first end of the analog-to-digital converter is electrically connected to the second end of the pressure sensor, and the second end of the analog-to-digital converter is electrically connected to the control module, and the analog-to-digital converter is used to process the pressure information in the form of an analog signal into pressure information in the form of a digital signal, and send the pressure information in the form of a digital signal to the control module.

[0009] According to another aspect of the present disclosure, a wearable non-invasive continuous blood pressure monitoring method is provided, comprising: in response to a blood pressure measurement instruction, controlling a wearable sensor to apply pressure to a target object, while receiving a pulse wave signal from the wearable sensor until the pressure satisfies a first predetermined condition, and generating a pulse wave oscillation curve, wherein the pulse wave oscillation curve comprises N pulse pulses constituted by the pulse wave signal, and N is a positive integer greater than 1; determining amplitude information of each of the N pulse pulses and time information corresponding to the amplitude information; generating a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve according to the amplitude information of each of the multiple pulse pulses and the time information corresponding to the amplitude information; generating continuous pulsating blood pressure information corresponding to the N pulse pulses according to the amplitude information of the pulse wave oscillation curve envelope.

[0010] According to an embodiment of the present disclosure, the pulse wave signal includes Q signal values, and the pulse wave signal is collected in the Mth time period, where Q and M are both positive integers; determining the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information, including: generating a first-order difference value corresponding to the qth signal according to the qth signal value and the q-1th signal value among the Q signal values, where q is a positive integer greater than 1 and less than or equal to Q; generating a first-order difference signal corresponding to the pulse wave signal according to the first-order difference value corresponding to the Q-1th signal value; generating a first-order difference signal corresponding to the pulse wave signal according to the first-order difference value corresponding to the Q-1th signal value and a predetermined threshold coefficient, calculate the differential threshold corresponding to the Mth time period; according to the differential threshold corresponding to the Mth time period, determine the differential peak points and J differential zero-crossing points corresponding to N pulse pulses from the first-order differential signal, where J is a positive integer greater than 1; according to the relative position relationship between the pulse pulse corresponding to the differential peak point and the pulse pulse corresponding to the J differential zero-crossing points, determine the maximum peak point and the minimum valley point in the pulse wave oscillation curve from the J differential zero-crossing points; according to the maximum peak point and the minimum valley point, generate the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information.

[0011] According to an embodiment of the present disclosure, a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve is generated based on the amplitude information of each of the multiple pulse pulses and the time information corresponding to the amplitude information, including: inputting the amplitude information of each of the multiple pulse pulses and the time information corresponding to the amplitude information into a first predetermined function, and fitting parameters of the first predetermined function are obtained by fitting; inputting the fitting parameters into a second predetermined function, and calculating Gaussian parameters; and obtaining the pulse wave oscillation curve envelope based on the Gaussian parameters and the Gaussian function.

[0012] According to an embodiment of the present disclosure, the amplitude information of the pulse wave oscillation curve envelope includes the maximum amplitude of the pulse wave oscillation curve envelope; based on the amplitude information of the pulse wave oscillation curve envelope, continuous pulsating blood pressure information corresponding to N pulse pulses is generated, including: determining the average blood pressure information of the target object based on the maximum amplitude of the pulse wave oscillation curve envelope; calculating the diastolic pressure information corresponding to the average blood pressure information based on the average blood pressure information and a predetermined diastolic pressure coefficient; calculating the systolic pressure information corresponding to the average blood pressure information based on the average blood pressure information and a predetermined systolic pressure coefficient; obtaining the continuous pulsating blood pressure information based on the diastolic pressure information and the systolic pressure information.

[0013] According to an embodiment of the present disclosure, continuous pulsating blood pressure information is obtained based on diastolic pressure information and systolic pressure information, including: generating Nth instantaneous pressure information corresponding to the Nth pulse pulse based on shape feature increment information, blood pressure increment information and N-1th instantaneous pressure information corresponding to the N-1th pulse pulse, wherein the shape feature increment information is generated based on predetermined system constants and shape feature error information corresponding to the shape feature information, the shape feature error information is generated based on the amplitude information and pulsation period of the pulse pulse, the blood pressure increment information is generated based on predetermined system constants and the pulse wave fluctuation signal corresponding to the pulse wave fluctuation signal, the pulse wave fluctuation signal is generated based on the pulse wave signal and the filtered pulse wave signal, the filtered pulse wave signal is obtained by filtering the pulse wave signal, and the instantaneous pressure information is used to characterize the wearable sensor's response to the target when collecting the pulse pulse. the instantaneous average pressure applied by the object; determining the pulsation coefficient according to the maximum amplitude and the minimum amplitude of the diastolic pressure information, the systolic pressure information and the pulsating blood pressure information corresponding to the first pulse pulse; generating the hydrostatic pressure difference information corresponding to the target object according to the blood density information, the gravity acceleration information and the height difference information of the target object, wherein the gravity acceleration information is determined according to the geographical location of the target object, and the height difference information represents the vertical height difference between the heart and the finger of the target object; generating continuous pulsating blood pressure information according to the Nth instantaneous pressure information, the pulsation coefficient, the pulsating blood pressure information and the hydrostatic pressure difference information, wherein the pulsating blood pressure information is obtained according to the pre-constructed transfer function and the pressure pulsation information in the pressure information, the pressure pulsation information is the force information generated in response to the pulsation of the target object, and the transfer function represents the correlation between the pulsating blood pressure information and the pressure pulsation information.

[0014] According to an embodiment of the present disclosure, the wearable non-invasive continuous blood pressure monitoring method further includes: inputting the sample pulse wave signal and the first sample pressure pulsation information into a target cross-correlation function to output phase delay information; when the phase delay information does not satisfy a third predetermined condition, inputting the second sample pressure pulsation information having a different phase from the first sample pressure pulsation information into the target cross-correlation function, until when the phase delay information satisfies the third predetermined condition, the sample pressure pulsation information corresponding to the phase delay information satisfying the third predetermined condition is determined as the target sample pressure pulsation information, wherein the target cross-correlation function is used to characterize the phase relationship between the sample pressure pulsation information and the sample pulse wave signal; generating normalized sample pressure pulsation information and a normalized sample pulse wave signal according to the target sample pressure pulsation information and the sample pulse wave signal; and performing phase shifting on the normalized sample pressure pulsation information according to a predetermined frequency. The normalized sample pressure pulsation information and the normalized sample pulse wave signal are sampled respectively to obtain K pressure pulsation amplitudes corresponding to the sample pressure pulsation information and K pulsating blood pressure amplitudes corresponding to the sample pulse wave signal, the k-th pressure pulsation amplitude among the K pressure pulsation amplitudes and the k-th pulsating blood pressure amplitude among the K pulsating blood pressure amplitudes both correspond to the k-th sampling moment among the K sampling moments, K is a positive integer greater than 1, and k is a positive integer less than or equal to K; the information of the K pressure pulsation amplitudes and the K sampling moments are input into the initial transfer function, and K predicted pulsating blood pressure amplitudes corresponding to the K sampling moments are output; the K predicted pulsating blood pressure amplitudes and the K pulsating blood pressure amplitudes are processed by using a pre-constructed loss function, and loss information is output; the function parameters of the initial transfer function are adjusted until the loss information meets the fourth predetermined condition, and the pre-constructed transfer function is obtained.

[0015] According to an embodiment of the present disclosure, based on the wearable non-invasive continuous blood pressure monitoring device of the present disclosure, pressure can be slowly applied to the target object by controlling the wearable sensor, and the pulse wave signal from the wearable sensor can be received at the same time, thereby generating a pulse wave oscillation curve corresponding to the blood pressure condition of the target object. Based on this, according to the amplitude information of the pulse pulse in the pulse wave oscillation curve and the time information corresponding to the amplitude information, a pulse wave oscillation curve envelope corresponding to the blood pressure condition of the target object can be generated. Based on this, the continuous pulsating blood pressure information of the target object can be generated according to the amplitude information of the pulse wave oscillation curve envelope.

[0016] Therefore, the device is based on the pulsating volume regulation technology of static pressure regulation, and can use a slow-moving fluid control mechanism to achieve continuous and accurate blood pressure measurement of the finger.

[0017] In addition, in response to the problem that some examples still require frequent calibration of external NBP (noninvasive blood pressure) standard blood pressure, the wearable noninvasive continuous blood pressure monitoring device disclosed in the present invention applies an oscillometric blood pressure measurement algorithm suitable for the open-loop stage to perform self-calibration of continuous blood pressure monitoring in the closed-loop stage through accurate and reliable oscillometric blood pressure amplitude information and time information corresponding to the amplitude information, thereby avoiding the above-mentioned frequent external calibration problem. In addition, the algorithm can be implemented regularly, thereby ensuring the accuracy of continuous blood pressure measurement during the entire measurement period. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above contents and other purposes, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0019] Figure 1 A schematic diagram of a wearable non-invasive continuous blood pressure monitoring device according to an embodiment of the present disclosure is schematically shown.

[0020] Figure 2 A schematic diagram of a wearable non-invasive continuous blood pressure monitoring device according to another embodiment of the present disclosure is schematically shown.

[0021] Figure 3 The following is a schematic diagram of a method for sending instructions according to an embodiment of the present disclosure.

[0022] Figure 4 A schematic diagram of a hydraulic structure according to an embodiment of the present disclosure is schematically shown.

[0023] Figure 5 The flowchart of the wearable non-invasive continuous blood pressure monitoring method according to an embodiment of the present disclosure is schematically shown.

[0024] Figure 6 A schematic diagram of a pulse wave signal and a first-order difference signal according to an embodiment of the present disclosure is schematically shown.

[0025] Figure 7 The flowchart schematically shows a method for detecting peak points and valley points of a pulse wave signal according to an embodiment of the present disclosure.

[0026] Figure 8 The figure schematically shows a waveform diagram of blood pressure measurement using the oscillometric method in the open-loop stage according to an embodiment of the present disclosure.

[0027] Fig. 9 A schematic diagram schematically shows a method for calculating blood pressure information according to an embodiment of the present disclosure.

[0028] Fig.10The flowchart of the wearable non-invasive continuous blood pressure monitoring device according to the embodiment of the present disclosure is schematically shown.

[0029] Fig.11 The schematic diagram shows a principle diagram of the closed-loop stage according to an embodiment of the present disclosure.

[0030] Fig.12 The diagram schematically shows the change in the shape of the pulse wave signal during the process of increasing the cuff pressure according to an embodiment of the present disclosure.

[0031] Fig.13 The flowchart of the method for constructing a transfer function according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0033] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0034] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0035] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0036] In the process of realizing the concept of the present disclosure, the inventors found that non-invasive continuous blood pressure monitoring technology not only avoids physical harm to patients, but also realizes continuous monitoring of blood pressure, becoming a new trend in the development of blood pressure monitoring technology. Among the non-invasive continuous blood pressure monitoring methods, the non-invasive continuous blood pressure monitoring technology based on volume control is a method that is more recognized in clinical applications.

[0037] Non-invasive continuous blood pressure monitoring technology based on volume control is mainly divided into two technologies, namely the constant volume method based on rapid volume control and the pulsatile volume control technology (PCVAT) based on slow volume control. The former controls the rapid inflation and deflation of the wearable sensor's finger cuff by combining the PPG (Photo PlethysmoGraphy) signal to keep the finger blood volume constant throughout the heart cycle, that is, in a clamped state, thereby capturing a continuous pulsating blood pressure waveform. The continuous blood pressure monitoring system based on the constant volume method is usually composed of mechanical components such as pumps, valves, and air hoses. It is too large and can generally only be used in clinical scenarios such as intensive care perioperative period. It cannot be used in wearable monitoring devices for general wards, individualized monitoring and other mobile monitoring scenarios.

[0038] In contrast to the constant volume method, the pulsatile cycle volume adjustment technology (PCVAT) adjusts the blood volume according to the time scale of the heart cycle, so that the blood volume can fluctuate with the heartbeat, effectively balancing the blood inflow and outflow of the finger arteries in each cardiac cycle. This method performs blood volume control at a slower rate, thereby enabling small hardware that can move slowly. As a portable non-invasive blood pressure monitoring tool, the wearable non-invasive continuous blood pressure monitoring system can not only reduce patient discomfort and infection risks, but also provide doctors with real-time and accurate blood pressure data to support clinical decision-making. It is particularly suitable for mobile monitoring scenarios such as general wards and remote home monitoring.

[0039] Based on this, the present invention provides a wearable continuous non-invasive Blood Pressure Monitor (WeBPM) and method based on pulsatile volume regulation technology, which can continuously and non-invasively measure cardiovascular parameters such as non-invasive continuous blood pressure on the limbs, avoiding the continuous and long-term compression load on the limb to be measured. The goal is also to provide a compact system consisting of a few independent components that can be integrated into a wearable sensor.

[0040] Figure 1A schematic diagram of a wearable non-invasive continuous blood pressure monitoring device according to an embodiment of the present disclosure is schematically shown.

[0041] like Figure 1 As shown, the wearable non-invasive continuous blood pressure monitoring device of this embodiment includes a wearable sensor 100 and a controller 200.

[0042] According to an embodiment of the present disclosure, the wearable sensor 100 can be worn on a target part of a target object so as to collect a pulse wave signal of the target object. The wearable sensor 100 can be a finger cuff sensor of a finger cuff style, etc. The wearable sensor 100 can include a liquid capsule 101. The wearable sensor 100 can include a liquid capsule 101 and a photoelectric signal collection element, etc. The liquid capsule 101 can be filled with silicone oil. The target object can be an object that has a blood pressure monitoring requirement. The target part can be a finger of the object, etc.

[0043] like Figure 2 As shown, the wearable sensor 100 may include an LED (Light Emitting Diode) and a PD (Photo-Diode). It should be noted that: Figure 2 Artery means artery and Vein means vein.

[0044] The controller 200 may include a control module 201, a PPG signal acquisition module 202, a motor drive module 203, a pressure sensor 204, an analog-to-digital converter 205, a motor 206, a limit switch 207, a syringe 208, a Bluetooth module 209, a battery power management module 210, a lithium battery 211, and an LCD (Liquid Crystal Display) touch screen. For example, the control module 201 may be constructed by an MCU (Micro Controller Unit). Based on this, the controller 200 may be used to realize functions such as the acquisition of finger PPG signals and pressure signals, the operation of a blood pressure monitoring algorithm, and Bluetooth communication. For example, information transmission between the Bluetooth module 209 and the control module 201 may be performed through a serial port. The serial port is a serial communication interface.

[0045] For example, the controller 200 can send data to the host computer using the Bluetooth communication method through the Bluetooth module 209. For example, the host computer can be a tablet computer 400. The host computer can be deployed with a graphical user interface (GUI) software, thereby realizing functions such as real-time display and storage of blood pressure waveforms and results and interactive control.

[0046] For example, the LCD touch screen can be used to implement human-computer interaction for the controller 200. Signal transmission between the LCD touch screen and the control module 201 can be performed via SPI (Serial Peripheral interface).

[0047] For example, the lithium battery 211 may be used to power the controller 200 . The battery power management module 210 may be used to manage the power supply status of the lithium battery 211 to the controller 200 .

[0048] For example, the controller 200 can be used to control the wearable sensor 100 to apply pressure to the target object in response to a blood pressure measurement instruction, and at the same time receive a pulse wave signal from the wearable sensor 100 until the pressure meets a first predetermined condition, and generate a pulse wave oscillation curve, wherein the pulse wave oscillation curve includes N pulse pulses composed of the pulse wave signal, and N is a positive integer greater than 1. For example, the blood pressure measurement instruction can be a start instruction for blood pressure monitoring. The pulse wave signal can be a PPG signal. For example, the controller 200 can collect LED signals and PPG signals from the wearable sensor 100 through the PPG signal acquisition module 202. For example, the signal transmission between the PPG signal acquisition module 202 and the control module 201 can be performed through SPI.

[0049] The first predetermined condition may be determined based on a predetermined pressure value. The predetermined pressure value may be a preset maximum value of systolic pressure. For example, since systolic pressure is high pressure, the preset maximum value of systolic pressure may represent the upper limit of the range of human blood pressure. When the pressure applied to the target object is greater than or equal to the predetermined pressure value, it is determined that the pressure satisfies the first predetermined condition. When the pressure applied to the target object is less than the predetermined pressure value, it is determined that the pressure does not satisfy the first predetermined condition. For example, when the above-mentioned device receives a blood pressure measurement instruction, the above-mentioned device slowly and linearly increases the pressure applied by the finger cuff sensor to the target object. When the pressure reaches a preset maximum value exceeding the systolic pressure, the above-mentioned device stops pressurizing and records an oscilloscope curve during the pressure increase process, and the oscilloscope curve is the above-mentioned pulse wave oscillation curve.

[0050] The controller 200 can also be used to determine the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information. For example, the cutoff frequency f c The oscillometric waveform (OMW) of the pulse wave oscillation curve is extracted by a 0.5 Hz high-pass filter, and the peaks and valleys of the oscillometric waveform are detected by a dynamic differential threshold method, so that the amplitude information of each pulse pulse and the time information corresponding to the amplitude information can be determined.

[0051] The controller 200 can also be used to generate a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve according to the amplitude information of each of the plurality of pulse pulses and the time information corresponding to the amplitude information. For example, an oscillometric waveform envelope (OMWE) can be constructed according to the amplitude information and the time information corresponding to the amplitude information using a least squares Gaussian fitting method based on pulse amplitude, and the oscillometric waveform envelope is the pulse wave oscillation curve envelope.

[0052] The controller 200 can also be used to generate continuous pulsating blood pressure information corresponding to N pulse pulses based on the amplitude information of the pulse wave oscillation curve envelope. For example, the maximum amplitude algorithm (MAA) can be used to process the pulse wave oscillation curve envelope to obtain the diastolic pressure information and systolic pressure information of the target object. Then, based on the diastolic pressure information and the systolic pressure information, the continuous pulsating blood pressure information is generated. It should be noted that the blood pressure information in the embodiment of the present disclosure is not directly used as a health diagnosis result, but provides a reference for blood pressure monitoring. The blood pressure information includes but is not limited to the above-mentioned diastolic pressure information, systolic pressure information and continuous pulsating blood pressure information. The continuous pulsating blood pressure information can be used to characterize the continuous blood pressure pulsation condition of the target object.

[0053] When the piston is at the target position, the limit switch 207 is closed to send a limit signal to the control module 201 via a closed loop corresponding to the limit switch 207, so that the control module 201 stops sending control signals to the motor drive module 203. The target position can be a pre-set position for limiting the advancement of the piston.

[0054] When the piston is not at the target position, the limit switch 207 is disconnected. When the limit switch 207 is disconnected, the control module 201 is also used to count the drive pulses, generate pulse quantity information, and determine that the pressure meets the first predetermined condition when the pulse quantity information meets the second predetermined condition. For example, the second predetermined condition can be determined based on a predetermined pulse quantity threshold. For example, when the pulse quantity information is greater than or equal to the predetermined quantity threshold, it is determined that the pulse quantity information meets the second predetermined condition. When the pulse quantity information is less than the predetermined quantity threshold, it is determined that the pulse quantity information does not meet the second predetermined condition.

[0055] Figure 3 The following is a schematic diagram of a method for sending instructions according to an embodiment of the present disclosure.

[0056] like Figure 3 As shown, the instruction sending method of this embodiment includes operations S301 to S308.

[0057] In operation S301 , a blood pressure measurement instruction is received.

[0058] In operation S302, the instruction is parsed.

[0059] In operation S303, is the limit switch closed? If yes, then operation S304 is performed; if no, then operation S305 is performed.

[0060] In operation S304, the motor stops operating.

[0061] In operation S305 , a driving pulse is transmitted to the motor.

[0062] In operation S306 , the driving pulses transmitted to the motor are counted to generate pulse number information.

[0063] In operation S307, does the pulse quantity information satisfy the second predetermined condition? If yes, then operation S308 is executed; if no, then the process returns to execute operation S306.

[0064] In operation S308, a completion instruction is sent to the host computer.

[0065] The first end of the pressure sensor 204 is connected to the liquid capsule 101 , so that the pressure sensor 204 can be used to collect information about the pressure applied by the liquid capsule 101 to the target object, and the collected pressure information is in the form of an analog signal.

[0066] The first end of the analog-to-digital converter 205 is electrically connected to the second end of the pressure sensor 204, and the second end of the analog-to-digital converter 205 is electrically connected to the control module 201. The analog-to-digital converter 205 is used to process the pressure information in the form of an analog signal into the pressure information in the form of a digital signal, and send the pressure information in the form of a digital signal to the control module 201. For example, the number of bits of the analog-to-digital converter 205 can be 16 bits. For example, the analog-to-digital converter 205 and the control module 201 can also perform signal transmission through SPI.

[0067] like Figure 4 As shown, the motor 206 may be a stepper motor. The stepper motor may be a 10 mm micro-stepping reduction motor with a reduction ratio of 200. After the stepper motor is decelerated by the reduction gear, the step angle can be further subdivided to increase the load torque and make the control more precise.

[0068] For example, the motor drive module 203 may include a power supply 203_1, a main controller 203_2 and a driver chip 203_3. Among them, the power supply 203_1 can be used to power the main controller 203_2 and the driver chip 203_3. The main controller 203_2 of the motor drive module 203 can be constructed based on a microcontroller of the STM32F030 model, and the main controller 203_2 is used to receive the control signal of the control module 201, and control the driver chip 203_3 to output the driving voltage through the control signal. For example, the model of the driver chip 203_3 can be DRV8834, etc. DRV8834 is a dual H-bridge motor driver designed for controlling stepper motors and DC motors. It can provide micro-stepping control of up to 1 / 32 steps, making the motor movement smoother and more precise. DRV8834 supports two control modes: simple STEP / DIRECTION (step / direction) control and PHASE / ENABLE (phase / enable) control, which can adapt to different application requirements. Its output current is 1.5A in continuous operation and can reach 2.2A at peak, meeting the driving requirements of various motors. In addition, DRV8834 also has low power design and dynamic decay mode, supports a wide range of power supply voltage, and is suitable for various low power and portable device applications. For example, the wide range of power supply voltage can be 2.5V to 10.8V.

[0069] The control module 201 can also be used to send a control signal to the motor drive module 203 in response to a blood pressure measurement instruction. For example, information transmission can also be performed between the motor drive module 203 and the control module 201 through a serial port. The motor drive module 203 can be used to output a drive pulse corresponding to the control signal to the motor 206. The motor 206 is connected to a screw nut disposed in the piston of the syringe 208 through a screw, and the injection head of the syringe 208 is located inside the liquid capsule 101. Based on this, the motor 206 can be used to rotate the screw according to the drive pulse to control the extension and contraction of the screw nut, thereby driving the piston to move, so as to adjust the liquid volume inside the liquid capsule 101 by changing the liquid volume inside the syringe 208, thereby controlling the pressure applied by the liquid capsule 101 to the target object.

[0070] Based on this, the change of pressure in the hydraulic system controls the extension and contraction of the screw nut connected to the piston of the syringe 208 by the rotation of the screw driven by the stepping motor, thereby realizing the change of the pressure in the liquid capsule 101 of the finger sleeve sensor. By controlling the pressure in the liquid capsule 101 of the finger sleeve sensor, the blood volume in the blood vessel can be controlled to remain constant.

[0071] In some embodiments, the wearable non-invasive continuous blood pressure monitoring device of the present disclosure may further include an altitude corrector 300. The altitude corrector 300 is used to compensate for the vertical hydrostatic pressure difference between the finger and the heart. For example, the altitude corrector 300 may exchange information with the control module 201 through a serial port.

[0072] According to an embodiment of the present disclosure, based on the wearable non-invasive continuous blood pressure monitoring device of the present disclosure, a pulse wave oscillation curve corresponding to the blood pressure condition of the target object can be generated by controlling the wearable sensor 100 to slowly apply pressure to the target object and simultaneously receiving the pulse wave signal from the wearable sensor 100. Based on this, a pulse wave oscillation curve envelope corresponding to the blood pressure condition of the target object can be generated according to the amplitude information of the pulse pulse in the pulse wave oscillation curve and the time information corresponding to the amplitude information. Based on this, the continuous pulsating blood pressure information of the target object can be generated according to the amplitude information of the pulse wave oscillation curve envelope.

[0073] Therefore, the device is based on the pulsating volume regulation technology of static pressure regulation, and can use a slow-moving fluid control mechanism to achieve continuous and accurate blood pressure measurement of the finger.

[0074] In addition, in response to the problem of frequent calibration of standard blood pressure of external NBP in some examples, the wearable non-invasive continuous blood pressure monitoring device disclosed in the present invention applies an oscillometric blood pressure measurement algorithm suitable for the open-loop stage to perform self-calibration of continuous blood pressure monitoring in the closed-loop stage through accurate and reliable oscillometric blood pressure amplitude information and time information corresponding to the amplitude information, thereby avoiding the above-mentioned frequent external calibration problem. In addition, the algorithm can be implemented regularly, thereby ensuring the accuracy of continuous blood pressure measurement during the entire measurement period.

[0075] Figure 5 The flowchart of the wearable non-invasive continuous blood pressure monitoring method according to an embodiment of the present disclosure is schematically shown.

[0076] like Figure 5 As shown, the wearable non-invasive continuous blood pressure monitoring method of this embodiment includes: operations S510 to S540.

[0077] In operation S510, in response to a blood pressure measurement instruction, the wearable sensor is controlled to apply pressure to the target object, and a pulse wave signal is received from the wearable sensor until the pressure meets a first predetermined condition, and a pulse wave oscillation curve is generated, wherein the pulse wave oscillation curve includes N pulse pulses composed of the pulse wave signal, and N is a positive integer greater than 1.

[0078] In operation S520, amplitude information of each of the N pulse pulses and time information corresponding to the amplitude information are determined.

[0079] In operation S530, a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve is generated according to the amplitude information of each of the plurality of pulse pulses and the time information corresponding to the amplitude information.

[0080] In operation S540, continuous pulsating blood pressure information corresponding to N pulse pulses is generated according to the amplitude information of the pulse wave oscillation curve envelope.

[0081] According to an embodiment of the present disclosure, by controlling the wearable sensor to slowly apply pressure to the target object and simultaneously receiving the pulse wave signal from the wearable sensor, a pulse wave oscillation curve corresponding to the blood pressure condition of the target object can be generated. Based on this, according to the amplitude information of the pulse pulse in the pulse wave oscillation curve and the time information corresponding to the amplitude information, a pulse wave oscillation curve envelope corresponding to the blood pressure condition of the target object can be generated. Based on this, the continuous pulsating blood pressure information of the target object can be generated according to the amplitude information of the pulse wave oscillation curve envelope.

[0082] Therefore, the wearable non-invasive continuous blood pressure monitoring method of this embodiment is based on the pulsating volume regulation technology of static pressure regulation, and a slowly moving fluid control mechanism can be used to achieve continuous and accurate blood pressure measurement of the finger.

[0083] In addition, in response to the problem of frequent calibration of standard blood pressure of external NBP in some examples, the present disclosure provides an oscillometric blood pressure measurement algorithm suitable for the open-loop stage, which can perform self-calibration of continuous blood pressure monitoring in the closed-loop stage through accurate and reliable oscillometric blood pressure amplitude information and time information corresponding to the amplitude information, thereby avoiding the above-mentioned frequent external calibration problem. In addition, the algorithm can be implemented regularly, so as to ensure the accuracy of continuous blood pressure measurement during the entire measurement period.

[0084] According to an embodiment of the present disclosure, the pulse wave signal includes Q signal values, and the pulse wave signal is collected in the Mth time period, and Q and M are both positive integers. Determining the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information includes: generating a first-order differential value corresponding to the qth signal according to the qth signal value and the q-1th signal value among the Q signal values, where q is a positive integer greater than 1 and less than or equal to Q. Generate a first-order differential signal corresponding to the pulse wave signal according to the first-order differential value corresponding to the Q-1 signal value. Calculate the differential threshold corresponding to the Mth time period according to the first-order differential value corresponding to the Q-1 signal value and a predetermined threshold coefficient. Determine the differential peak point and J differential zero crossing points corresponding to the N pulse pulses from the first-order differential signal according to the differential threshold corresponding to the Mth time period, where J is a positive integer greater than 1. According to the relative position relationship between the pulse pulse corresponding to the differential peak point and the pulse pulse corresponding to the J differential zero-crossing points, the maximum peak point and the minimum valley point in the pulse wave oscillation curve are determined from the J differential zero-crossing points. According to the maximum peak point and the minimum valley point, the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information are generated.

[0085] According to an embodiment of the present disclosure, in order to reduce the influence of noise and power frequency interference on the detection of PPG signal feature points, a Butterworth low-pass filter can be used to pre-process the PPG original signal to remove high-frequency noise and power frequency interference.

[0086] According to an embodiment of the present disclosure, the first-order difference value of the PPG signal can be calculated by the following formula (7):

[0087] d(q)=y(q)-y(q-1) (I)

[0088] Wherein, d(q) may represent the first-order difference value corresponding to the qth signal. y(q) may represent the qth signal value. y(q-1) may represent the q-1th signal value.

[0089] In the first period, when acquiring a PPG signal with 500 sampling points, the initial differential threshold is determined, and the predetermined threshold coefficient is obtained based on debugging experience. Formula (2) for determining the differential threshold is expressed as:

[0090] Threshold=0.4*max(D),D=[d(0),...,d(500)] (2)

[0091] Among them, d(0), ..., d(500) can correspond to d(q) in the above formula (1), which will not be repeated here. Threshold can represent the above differential threshold. 0.4 can be the above predetermined threshold coefficient. D can represent a first-order differential signal with a window size of 500 sampling points. The selection of the window size can be determined by the pulse rate of the target object and the sampling rate of the PPG signal. The above Q signal values ​​can be obtained by sampling the PPG signal according to the sampling point. The window needs to contain 1-3 pulsation cycles, which can be determined according to the cardiac cycle of the target object. The dynamic differential threshold setting period can be the same as the processing period of the PPG signal, which is updated every 10 sampling points. Based on this, formula (2) can be transformed into the following formula (3). It should be noted that the symbols in formula (3) have the same meaning as the symbols in formula (2), which will not be repeated here.

[0092] Threshold=0.4*max(D), D=[d(q-500),...,d(q)] (3)

[0093] According to an embodiment of the present disclosure, the differential peak point of the first-order differential signal is a maximum point that exceeds the current dynamic differential threshold. That is, the differential peak point of the first-order differential signal satisfies the following conditions:

[0094]

[0095] Wherein, T may represent the differential peak point. Threshold may represent the above-mentioned differential threshold. d(q) may represent the above-mentioned first-order differential value corresponding to the qth signal. d(q-1) may represent the above-mentioned first-order differential value corresponding to the q-1th signal. d(q-2) may represent the above-mentioned first-order differential value corresponding to the q-2th signal. d(q+1) may represent the above-mentioned first-order differential value corresponding to the qth signal. d(q+1) may represent the above-mentioned first-order differential value corresponding to the qth signal. d(q+2) may represent the above-mentioned first-order differential value corresponding to the q+2th signal.

[0096] like Figure 6 As shown in the figure, the fixed window size can be set according to the signal sampling rate. For the detection of the maximum peak point of the PPG signal, the first differential zero-crossing point in the fixed window behind the differential peak point is the maximum peak point. For the detection of the minimum valley point of the PPG signal, the first differential zero-crossing point in the fixed window forward of the differential peak point is the minimum valley point. It should be noted that in Figure 6 In the example, the differential target peak point is the differential peak point. Threshold can represent the differential threshold. Zero can represent 0.

[0097] According to an embodiment of the present disclosure, when the waveform of the PPG signal is subject to large-scale body movement or strong external interference, the waveform of the PPG signal will be distorted, which will lead to false detection of the peak point. In order to effectively deal with this problem, the time window technology and heart rate analysis can be combined to perform subsequent verification on the suspected peaks, and discard and exclude false detections caused by non-physiological fluctuations. For example, the pulse rate calculated based on the peak point and valley point of the PPG signal this time and the peak point and valley point of the PPG signal monitored last time can be used to determine whether the peak point is falsely detected.

[0098] Figure 7 The flowchart schematically shows a method for detecting peak points and valley points of a pulse wave signal according to an embodiment of the present disclosure.

[0099] like Figure 7 As shown, the method for detecting the peak point and the valley point of the pulse wave signal of this embodiment includes operations S710 to S780.

[0100] In operation S710, a pulse wave signal is low-pass filtered to obtain a filtered pulse wave signal.

[0101] In operation S720, a first-order difference signal is generated according to a signal value in the filtered pulse wave signal.

[0102] In operation S730, a differential peak point is determined from the first-order differential signal.

[0103] In operation S740, it is determined whether the value of the differential peak point is greater than the differential threshold. If yes, S750 is executed; if no, S780 is executed.

[0104] In operation S750, peak points and valley points corresponding to J differential zero-crossing points are determined within the front and rear windows based on the differential peak points.

[0105] In operation S760, it is determined whether the peak point and the valley point are misdetected. If yes, operation S780 is performed; if no, operation S770 is performed.

[0106] In operation S770, the detection is completed.

[0107] In operation S780, the detected peak points and valley points are discarded and detection is restarted.

[0108] Based on this, the peak point and valley point of each pulse pulse can be determined in turn by the above method. Based on this, the amplitude difference between the peak point and the valley point can be used as the amplitude information of the pulse pulse, and the time information corresponding to the peak point and the time information corresponding to the valley point can be determined as the time information corresponding to the above amplitude information.

[0109] According to the embodiments of the present disclosure, by calculating the first-order differential signal according to the signal value in the pulse wave signal, the peak point and valley point of each pulse pulse can be extracted one by one, thereby improving the efficiency and accuracy of extracting the peak point and valley point of the pulse pulse. In addition, by dynamically adjusting the differential threshold according to the real-time characteristics of the signal, it can adapt to the change of signal amplitude and different noise levels, thereby improving the accuracy and robustness of detecting peak points and valley points.

[0110] According to an embodiment of the present disclosure, a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve is generated according to the amplitude information of each of the plurality of pulse pulses and the time information corresponding to the amplitude information, including: inputting the amplitude information of each of the plurality of pulse pulses and the time information corresponding to the amplitude information into a first predetermined function, fitting to obtain fitting parameters of the first predetermined function. Inputting the fitting parameters into a second predetermined function, calculating to obtain Gaussian parameters. According to the Gaussian parameters and the Gaussian function, the pulse wave oscillation curve envelope is obtained.

[0111] According to the embodiment of the present disclosure, after the amplitude points of the oscillometric waveform are extracted, a set of discrete data points (x i ,y i ), i = 1, 2, 3, ..., n, where x i is a time series point, which is the above-mentioned moment information. i is the amplitude point of the corresponding oscilloscope waveform, which is the amplitude information mentioned above. The relationship between the two is very similar to the Gaussian function, and the expression of the Gaussian function is shown in the following formula:

[0112]

[0113] Among them, A, B, and C are all Gaussian parameters that need to be solved. Among them, A can represent the height of the Gaussian curve. B can represent the peak point of the Gaussian curve at the horizontal coordinate position. There is a correlation between C and the half-maximum full width of the Gaussian curve.

[0114] Taking the natural logarithm of both sides of formula (5) yields:

[0115]

[0116] Based on this, we can assume:

[0117] z i =ln y i (7)

[0118]

[0119]

[0120]

[0121] Among them, b0, b1 and b2 can represent the above-mentioned fitting parameters.

[0122] Based on this, formula (6) can be converted into a polynomial fitting function as shown in the following formula (11):

[0123]

[0124] If all discrete data points are considered, the above formula (11) can be reconstructed in the form of a matrix to obtain formula (12), which is the above first predetermined function:

[0125]

[0126] It should be noted that, in some embodiments, measurement errors may also be considered, and formula (12) may be modified to obtain the following formula (13):

[0127]

[0128] in, The above measurement error can be expressed.

[0129] By calculating formula (12) using the least squares method, we can obtain b0, b1 and b2. The Gaussian parameters that need to be solved are:

[0130]

[0131]

[0132]

[0133] Wherein, formulas (14) to (16) can all be the above-mentioned second predetermined function. Thus, the Gaussian curve envelope of the oscillometric waveform can be obtained, that is, the above-mentioned pulse wave oscillation curve envelope. It should be noted that the same symbols used in the above-mentioned formulas (5) to (16) represent the same meanings, which will not be repeated here.

[0134] According to an embodiment of the present disclosure, the amplitude information of each of a plurality of pulse pulses and the time information corresponding to the amplitude information are input into a first predetermined function, fitting parameters of the first predetermined function are obtained by fitting, and then the fitting parameters are input into a second predetermined function to calculate Gaussian parameters. Thus, based on the Gaussian parameters and the Gaussian function, an accurate pulse wave oscillation curve envelope can be obtained, thereby improving the accuracy of the generated continuous pulsating blood pressure information.

[0135] According to an embodiment of the present disclosure, the amplitude information of the pulse wave oscillation curve envelope includes the maximum amplitude of the pulse wave oscillation curve envelope. Based on the amplitude information of the pulse wave oscillation curve envelope, continuous pulsating blood pressure information corresponding to N pulse pulses is generated, including: determining the average blood pressure information of the target object based on the maximum amplitude of the pulse wave oscillation curve envelope. Based on the average blood pressure information and a predetermined diastolic pressure coefficient, the diastolic pressure information corresponding to the average blood pressure information is calculated. Based on the average blood pressure information and a predetermined systolic pressure coefficient, the systolic pressure information corresponding to the average blood pressure information is calculated. Based on the diastolic pressure information and the systolic pressure information, the continuous pulsating blood pressure information is obtained.

[0136] like Figure 8 As shown in FIG. 1 , the systolic pressure information and the diastolic pressure information can be calculated by using the maximum amplitude algorithm (MAA). Figure 8 In the above, Pressure may represent blood pressure. SBP may represent systolic pressure. DBP may represent diastolic pressure. MAP may represent mean blood pressure. The mean blood pressure may refer to mean arterial pressure. time may represent time. Amplitude may represent amplitude. max It can represent the maximum amplitude of the oscillation amplitude of the pulse wave oscillation curve envelope. s The coefficient that can represent systolic blood pressure. d can represent the coefficient of diastolic pressure. Peaks can represent peak points. Valleys can represent valley points. Pc(t) can represent the pressure applied by the wearable sensor to the target object. LF (t) is the blood pressure DC component signal after passing through a low-pass filter.

[0137] For example, arterial compliance is at its maximum when arterial pressure equals mean blood pressure. This occurs when arterial wall dilation is minimal.

[0138] Based on this, the pressure of the cuff when the pulse wave oscillation curve envelope reaches the maximum value is approximated as the average blood pressure. Therefore, the maximum amplitude of the pulse wave oscillation curve envelope can be determined as the average blood pressure of the target object. The systolic pressure and diastolic pressure can be obtained by calculating the two time points when the cuff pressure is equal to the systolic pressure and the diastolic pressure. This means that when the oscillation amplitude of the pulse wave oscillation curve envelope reaches a certain fraction of its maximum value, the systolic pressure information and the diastolic pressure information can be identified based on the pulse wave oscillation curve envelope. The diastolic pressure can be found at the position where the cuff pressure is lower than the average blood pressure, and the systolic pressure can be found on the side where the cuff pressure is higher than the average blood pressure. The coefficient of systolic pressure may reach 0.45 to 0.73, and the coefficient of diastolic pressure may reach 0.69 to 0.83. The specific values ​​of the coefficient of systolic pressure and the coefficient of diastolic pressure are determined based on empirical data.

[0139] Taking into account the differences between brachial artery pressure and finger pressure, the systolic and diastolic coefficients can be fine-tuned over different pressure ranges of mean blood pressure to mitigate the effects of these differences. Systolic and diastolic information can be calculated periodically during the open loop phase, typically every half hour, to ensure consistent accuracy throughout the measurement period.

[0140] Fig. 9 A schematic diagram schematically shows a method for calculating blood pressure information according to an embodiment of the present disclosure.

[0141] like Fig. 9 As shown, the blood pressure information calculation method of this embodiment includes operations S910 to S970.

[0142] In operation S910, during a process in which the pressure applied by the wearable sensor to the target object increases, a pulse wave signal is collected to generate a pulse wave oscillation curve.

[0143] In operation S920, the pulse wave oscillation curve is processed by a high-pass filter with a cutoff frequency of 0.5 Hz to obtain an oscillometric waveform.

[0144] In operation S930, amplitude information of the pulse pulse and time information corresponding to the amplitude information are extracted according to the oscillometric waveform.

[0145] In operation S940, a pulse wave oscillation curve envelope is generated using Gaussian fitting according to the amplitude information of the pulse pulse and the time information corresponding to the amplitude information.

[0146] In operation S950, average blood pressure information of the target subject is determined according to a pressure corresponding to a maximum amplitude of the pulse wave oscillation curve envelope.

[0147] In operation S960, diastolic pressure information corresponding to the average blood pressure information is calculated based on the average blood pressure information and a predetermined diastolic pressure coefficient.

[0148] In operation S970, systolic pressure information corresponding to the average blood pressure information is calculated based on the average blood pressure information and a predetermined systolic pressure coefficient.

[0149] like Fig.10 As shown in the open loop stage, its main task is to determine the initial setting value P of the finger cuff pressure. MAP Or the initial mean blood pressure MAP during the closed-loop phase Init This phase also includes the calculation of the initial systolic blood pressure (SBP) based on the oscillometric method. Init and initial diastolic blood pressure DBP Init , providing self-calibration values ​​for the subsequent closed-loop stage.

[0150] The initial setting value P of the finger cuff pressure is obtained in the open loop stage MAP, the system will transition to the closed-loop stage. The closed-loop stage is based on the pulsatile volume regulation technology to track the continuous average blood pressure and reconstruct the pulsatile blood pressure waveform. At the beginning of the closed-loop stage, the system pre-adjusts the finger cuff pressure to the initial set value P MAP Then, it performs closed-loop feedback control to track mean arterial pressure (MAP) by extracting and analyzing the PPG signal V(t). c (t) and V(t), and reconstruct the waveform P of continuous pulsating blood pressure information BP (t), using SBP Init and DBP Init Calibration is performed to achieve continuous non-invasive blood pressure measurement, and systolic pressure SBP, diastolic pressure DBP and mean blood pressure MAP can be obtained.

[0151] The following combination Fig.11 and Fig.12 To illustrate the blood pressure waveform reconstruction process of the present invention.

[0152] According to an embodiment of the present disclosure, continuous pulsating blood pressure information is obtained according to diastolic pressure information and systolic pressure information, including: generating the Nth instantaneous pressure information corresponding to the Nth pulse pulse according to the shape feature increment information, the blood pressure increment information and the N-1th instantaneous pressure information corresponding to the N-1th pulse pulse, wherein the shape feature increment information is generated according to the predetermined system constant and the shape feature error information corresponding to the shape feature information, the shape feature error information is generated according to the amplitude information and the pulsation period of the pulse pulse, the blood pressure increment information is generated according to the predetermined system constant and the pulse wave fluctuation signal corresponding to the pulse wave fluctuation signal, the pulse wave fluctuation signal is generated according to the pulse wave signal and the filtered pulse wave signal, the filtered pulse wave signal is obtained by filtering the pulse wave signal, and the instantaneous pressure information is used to characterize the instantaneous average pressure applied by the wearable sensor to the target object when collecting the pulse pulse. According to the diastolic pressure information, the systolic pressure information and the maximum amplitude and the minimum amplitude of the pulsating blood pressure information corresponding to the first pulse pulse, the pulsation coefficient is determined. According to the target object's blood density information, gravity acceleration information and altitude difference information, the hydrostatic pressure difference information corresponding to the target object is generated, wherein the gravity acceleration information is determined according to the target object's geographical location, and the altitude difference information represents the vertical height difference between the target object's heart and fingers. According to the Nth instantaneous pressure information, pulsation coefficient, pulsating blood pressure information and hydrostatic pressure difference information, the continuous pulsating blood pressure information is generated according to the pre-constructed transfer function and the pressure pulsation information in the pressure information, and the pressure pulsation information is the force information generated in response to the pulsation of the target object, and the transfer function represents the correlation between the pulsating blood pressure information and the pressure pulsation information.

[0153] According to an embodiment of the present disclosure, the pulsatile volume adjustment technology uses shape feature information and physiological components of the pulse wave signal to determine and adjust the cuff pressure.

[0154] Fig.11 The figure shows the process of MAP tracking and blood pressure waveform reconstruction in the closed-loop stage using pulsating volume regulation technology based on the PPG signal V(t) and its derivative signal (blue signal flow). In this process, the pulse wave signal V(t) is filtered by a high-pass digital filter (cutoff frequency f c =0.2Hz) to generate a pulsating PPG signal V pulse (t), the pulsating PPG signal V pulse (t) is the filtered pulse wave signal. physio (t) is a PPG physiological fluctuation signal caused by physiological factors, and the PPG physiological fluctuation signal is the pulse wave fluctuation signal mentioned above. It should be noted that the same symbols used in the following formulas (17) to (26) represent the same meanings, and this disclosure will not elaborate on this:

[0155] V physio (t)=V(t)-V pulse (t) (17)

[0156] Under different cuff pressures, the PPG signal will show different shape characteristics due to different amplitudes. Therefore, the present disclosure introduces the PPG shape index Prop to quantify these shape characteristics. The PPG shape index Prop is the above shape characteristic information. Prop is defined as the V pulse The ratio of the mean value of (t) to its amplitude:

[0157]

[0158] Among them, V pulse_max Indicates V in a single pulse cycle pulse The maximum value of (t). V pulse_min Indicates V in a single pulse cycle pulse (t) is the minimum value. T represents the time of one pulsation cycle.

[0159] Based on this, Fig.12 As shown in (b), when the finger cuff pressure is P MAP , pulsating PPG signal V pulse (t) The waveform Prop = 0.5. Fig.12 As shown in (a), if the finger cuff pressure is lower than P MAP (P MAP- ), then V pulse The amplitude of (t) is small and the waveform is relatively wide (indicated by the orange line), indicating that Prop>0.5. Fig.12 As shown in (c), if the finger cuff pressure is higher than P MAP (P MAP+ ), V pulse (t) also exhibits a smaller amplitude, but the waveform is sharper (indicated by the green line), indicating that Prop < 0.5. Therefore, the PPG shape index Prop can be used to track MAP. In addition, V physio (t) can be used to quickly track rapid changes in MAP due to physiological changes.

[0160] The pulsating volume regulation technology adopts the principle of Prop = 0.5 and V physio (t) = 0 to continuously track MAP:

[0161] P MAP (n) = P MAP (n-1)+ΔP Prop (n)+ΔP physio (n) 19)

[0162] Among them, P MAP (n) may be the Nth instant pressure information mentioned above. MAP (n-1) may be the N-1th instantaneous pressure information mentioned above. ΔP Prop (n) can be the shape feature increment information. ΔP physio (n) may be blood pressure increment information.

[0163] ΔP Prop (n) and ΔP physio (n) According to Prop and V physio (t) to calculate:

[0164]

[0165] Among them, the K P_Prop , K I_Prop and K D_Prop That is, it is the predetermined system constant corresponding to the shape feature information. P_Prop , K I_Prop and K D_Prop They are the proportional constant, integral constant and differential constant of the continuous control system based on Prop respectively.

[0166]

[0167] Among them, the K P_physio , K I_physio and K D_physio That is, it is the predetermined system constant corresponding to the pulse wave fluctuation signal. P_physio , K I_physio and K D_physio Based on V physio (t) The proportional constant, integral constant and differential constant of a continuous control system.

[0168] In formula (16), the shape feature error information e Prop (n) is defined as:

[0169] e Prop (n)=Prop(n)-0.5 (22)

[0170] In formula (17), Defined as V in the ith pulsation cycle physio The average value of (i):

[0171]

[0172] Unlike conventional constant volume control systems, pulsating volume regulation technology operates on the basis of a pulsating cycle and uses slow pressure adjustment to maintain a constant volume waveform, thereby ensuring that the average pressure P in the cuff isMAP Always matches MAP.

[0173] In the process of tracking MAP using pulsatile volume modulation technology, the relationship between vascular PV and P MAP (t) is in an approximately linear state. Therefore, P MAP (t) and the signal derived from V(t) to reconstruct the continuous pulsatile blood pressure waveform P BP (t):

[0174] P BP (t) = P MAP (t)+k·V BP (t)-P H (t) (24)

[0175] in:

[0176]

[0177] P H (t) = ρ·g·Δh (26)

[0178] P MAP (t) is P c (t) through the cutoff frequency f c = 0.2Hz low-pass digital filter, representing the average pressure of the cuff. BP (t) is the pulsatile blood pressure information, which is closer to the contour of the real blood pressure waveform. BP (t) is obtained by processing the pressure pulsation information using the transfer function. The transfer function is obtained by using the filtered pulse wave signal V pulse (t) and pressure pulsation information P pulse (t) can be derived from the system identification of V. pulse (t) and P pulse (t) Determine the function parameters of the transfer function. SBP Init and DBP Init It is the value determined in the open loop phase or the calibration value obtained externally. BP_sys It is the initial stage V BP The maximum value of (t) is the maximum amplitude of the pulsating blood pressure information corresponding to the first pulse pulse. BP_dia It is the initial stage V BP The minimum value of (t) is the minimum amplitude of the pulsating blood pressure information corresponding to the first pulse pulse. H (t) represents the hydrostatic pressure difference information calculated by the heart reference system based on the vertical distance difference between the heart and the finger. ρ represents blood density information. g represents gravity acceleration information. Δh represents height difference information. During the initial calibration, PMAP (t) Calibration is performed by subtracting the initial hydrostatic pressure differential information.

[0179] Based on this, the wearable non-invasive continuous blood pressure monitoring method based on pulsating volume regulation technology disclosed in the present invention, its MAP tracking and continuous pulsating blood pressure reconstruction algorithm in the closed-loop stage, is used for continuous blood pressure measurement in the closed-loop stage. The algorithm controls the finger cuff pressure based on the scale of the pulsating cycle by analyzing the morphological characteristics and physiological components of the PPG signal in each cycle. Its uniqueness lies in that it combines the physiological components of the pulsating PPG signal shape factor PPG for control. This method is used to track slow blood pressure changes and rapid physiological changes (such as breathing), enhancing the real-time and efficiency of monitoring blood pressure and vasoconstriction and tension changes.

[0180] According to an embodiment of the present disclosure, the wearable non-invasive continuous blood pressure monitoring method further includes: inputting the sample pulse wave signal and the first sample pressure pulsation information into a target cross-correlation function, and outputting phase delay information. When the phase delay information does not satisfy the third predetermined condition, the second sample pressure pulsation information having a different phase from the first sample pressure pulsation information is input into the target cross-correlation function, until the phase delay information satisfies the third predetermined condition, the sample pressure pulsation information corresponding to the phase delay information satisfying the third predetermined condition is determined as the target sample pressure pulsation information, wherein the target cross-correlation function is used to characterize the phase relationship between the sample pressure pulsation information and the sample pulse wave signal. According to the target sample pressure pulsation information and the sample pulse wave signal, the normalized sample pressure pulsation information and the normalized sample pulse wave signal are generated. According to a predetermined frequency, the normalized sample pressure pulsation information and the normalized sample pulse wave signal are sampled respectively to obtain K pressure pulsation amplitudes corresponding to the sample pressure pulsation information and K pulsating blood pressure amplitudes corresponding to the sample pulse wave signal, and the k-th pressure pulsation amplitude among the K pressure pulsation amplitudes and the k-th pulsating blood pressure amplitude among the K pulsating blood pressure amplitudes both correspond to the k-th sampling moment among the K sampling moments, K is a positive integer greater than 1, and k is a positive integer less than or equal to K. The information of the K pressure pulsation amplitudes and the K sampling moments is input into the initial transfer function, and K predicted pulsating blood pressure amplitudes corresponding to the K sampling moments are output. The K predicted pulsating blood pressure amplitudes and the K pulsating blood pressure amplitudes are processed using a pre-constructed loss function, and loss information is output. The function parameters of the initial transfer function are adjusted until the loss information meets the fourth predetermined condition, and the pre-constructed transfer function is obtained.

[0181] According to an embodiment of the present disclosure, the third predetermined condition may be determined based on a predetermined phase delay value. For example, when the phase delay information is greater than the predetermined phase delay value, it may be determined that the phase delay information does not satisfy the third predetermined condition. When the phase delay information is less than or equal to the predetermined phase delay value, it may be determined that the phase delay information satisfies the third predetermined condition.

[0182] According to an embodiment of the present disclosure, the sample pulse wave signal may be a filtered pulse wave signal, and thus V pulse (t) represents the sample pulse wave signal. For the reconstruction of continuous pulsating blood pressure, if V pulse (t) superimposed on P MAP (t) Reconstruct P BP (t), resulting in the blood pressure waveform having the contour of the PPG waveform, which will cause the reconstructed blood pressure waveform to be distorted and affect the calculation of subsequent hemodynamic parameters. C (t) Still includes a small amplitude BP (Blood Pressure) pulsation signal P pulse (t), the P pulse (t) is the pressure pulsation information mentioned above. The present invention proposes to use system identification technology to estimate V pulse (t) and P pulse (t) The linear transfer function relationship between them. The design steps of the linear transfer function for system identification are as follows:

[0183] V pulse (t) and P pulse (t) phase matching. Although V pulse (t) and P pulse (t) is obtained by synchronous acquisition and filtering, but due to the different arrival times of the optical signal and the pressure signal, P pulse (t) relative to V pulse (t) has a certain time delay. In order to simplify the delay estimation and computational complexity during model identification, the cross-correlation method is used to eliminate V pulse (t) and P pulse (t) The phase delay between V pulse (t) and P pulse (t) are all discrete signals after sampling, and their cross-correlation functions are as follows:

[0184]

[0185] In formula (27), R VP The horizontal coordinate corresponding to the peak point of the function is V pulse (t) and P pulse (t) and then realize Vpulse (t) and P pulse For example, by changing n, the cyclic shift of the phase can be achieved, and then the second sample pressure pulsation information P with different phases can be used. pulse (t) is related to the sample pulse wave signal V pulse (t) to perform phase matching. Both n and m can represent phase.

[0186] Use Min-Max normalization to normalize the two signals. Since the blood pressure waveform is estimated, each set of signals needs to be normalized and limited. The specific method is to map the signal result value to the interval [0, 1]:

[0187]

[0188]

[0189] Among them, V* pulse (i) and P* pulse (i) represents the normalized sample pulse wave signal and the normalized sample pressure pulsation information respectively; V pulse_max and P pulse_max Respectively represent V pulse and P pulse The maximum value of V pulse_min and P pulse_min Respectively represent V pulse and P pulse The minimum value of V pulse (i) and P pulse (i) represents the i-th data respectively.

[0190] K groups can be generated based on K pressure pulsation amplitudes and K pulsation blood pressure amplitudes, and then the K groups are divided into training data and verification data. Each group of time series data is divided into two parts in a ratio of 7:3, which serve as training data for identifying function parameters and verification data for evaluating function performance. pulse (t) and P pulse The sampling frequency of (t) is 250 Hz.

[0191] For the architecture used to build the transfer function, considering the linear parameter relationship between the input (PPG) and the output (BP), and due to its numerical stability and low parameter estimation error, the auto-regressive with eXogenous function (ARX) becomes our preferred function. In the ARX transfer function, the input x(t) and output y(t) at discrete sampling time t are related by the following equation:

[0192]

[0193] In the ARX transfer function, a(k) and b(k) represent the coefficients of the denominator and numerator, respectively. The orders of the denominator and numerator are represented by n a and n b , where n k represents the delay between input and output, and ε(t) is the residual noise. Since phase matching is used for signal preprocessing, in this example, n k Set to 0. This model can be called ARX[n a n b n k ]. t can represent time.

[0194] Perform system identification using V pulse Reconstruction P pulse Assuming that the transfer function impulse response sequence of the selected ARX transfer function is T(n), in a discrete system, the input V pulse (n) Output P pulse The relationship between (n) is:

[0195]

[0196] According to the requirements of the physiological changes of blood pressure on the convergence speed and model stability, the recursive least squares adaptive filter can be selected for system identification. Formula (22) can be transformed into the following loss function:

[0197]

[0198] in, is the estimated signal data of T(n), which can be obtained based on experience. λ represents the different forgetting speeds of old data, called the forgetting factor (0<λ<1).

[0199] In order to make the loss information of the loss function L in formula (32) satisfy the fourth predetermined condition, the function parameters of the transfer function are adjusted through the following process. For example, the fourth predetermined condition may refer to a predetermined loss value. In the case where the loss information is greater than the predetermined loss value, it is determined that the loss information does not satisfy the fourth predetermined condition. In the case where the loss information is less than or equal to the predetermined loss value, it is determined that the loss information satisfies the fourth predetermined condition:

[0200] Parameter initialization: Initialization P(0)=δ -1 I. δ is a small positive number that can be obtained based on experience. I is the identity matrix.

[0201] Update the gain vector:

[0202]

[0203] ③Update model coefficients:

[0204]

[0205] ④Update the Riccati equation:

[0206]

[0207] Where I is the unit matrix. It should be noted that the meanings of the symbols in the above formulas (33) to (35) are the same as those in the above formulas (27) to (32), and are not described in detail here.

[0208] According to an embodiment of the present disclosure, in order to evaluate the fit between the model and the actual system in the verification phase, the following goodness of fit indicator Fit is used:

[0209]

[0210] Among them, ||·|| represents the 2-norm, is the estimated BP value, y is the actual BP value, is the mean value of y.

[0211] Fig.13 The flowchart of the method for constructing a transfer function according to an embodiment of the present disclosure is schematically shown.

[0212] like Fig.13 As shown, the method for constructing the transfer function of this embodiment includes operations S1310 to S1360.

[0213] In operation S1310, target sample pressure pulsation information that matches a phase of the sample pulse wave signal is obtained according to the sample pulse wave signal.

[0214] In operation S1320, normalized sample pressure pulsation information and a normalized sample pulse wave signal are generated according to the target sample pressure pulsation information and the sample pulse wave signal.

[0215] In operation S1330, the normalized sample pressure pulsation information and the normalized sample pulse wave signal are sampled at a predetermined frequency to obtain K pressure pulsation amplitudes and K pulsating blood pressure amplitudes.

[0216] In operation S1340, information of K pressure pulsation amplitudes and K sampling moments are input into an initial transfer function, and K predicted pulsating blood pressure amplitudes corresponding to the K sampling moments are output.

[0217] In operation S1350, the K predicted pulsatile blood pressure amplitudes and the K pulsatile blood pressure amplitudes are processed using a pre-constructed loss function, and loss information is output.

[0218] In operation S1360, function parameters of the initial transfer function are adjusted until the loss information satisfies a fourth predetermined condition, thereby obtaining a pre-constructed transfer function.

[0219] So far, the embodiments of the present disclosure have been described in detail in conjunction with the accompanying drawings. It should be noted that the implementation methods not shown or described in the drawings or the body of the specification are all forms known to ordinary technicians in the relevant technical field and are not described in detail. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and ordinary technicians in the field can simply change or replace them.

[0220] Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted when they may cause confusion in the understanding of the present disclosure.

[0221] Moreover, the shapes and sizes of the components in the figures do not reflect the real size and proportion, but only illustrate the contents of the embodiments of the present disclosure. In addition, in the claims, any reference symbols between brackets shall not be constructed as limiting the claims.

[0222] Unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can vary according to the desired properties obtained through the content of the present disclosure. In particular, all numbers used in the specification and claims to express the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0223] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element, or the order in the manufacturing method. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0224] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems may also be used together with the enlightenment based thereon. According to the above description, it is apparent that the structure required for constructing such systems is. In addition, the present disclosure is not directed to any particular programming language either. It should be understood that various programming languages ​​may be utilized to implement the disclosure described herein, and the description of the specific languages ​​above is for the purpose of disclosing the best mode of implementation of the present disclosure.

[0225] The present disclosure can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. The various component embodiments of the present disclosure can be implemented in hardware, or implemented in software modules running on one or more processors, or implemented in a combination thereof. It should be understood by those skilled in the art that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all functions of some or all components in the related equipment according to the embodiments of the present disclosure. The present disclosure can also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present disclosure can be stored on a computer-readable medium, or can have the form of one or more signals.

[0226] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and set in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition they may be divided into multiple submodules or subunits or subcomponents. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose. Furthermore, in a unit claim that lists several devices, several of these devices may be embodied by the same hardware item.

[0227] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the following intention: the claimed disclosure requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, the disclosed aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present disclosure.

[0228] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A wearable non-invasive continuous blood pressure monitoring device, comprising: A wearable sensor, worn on a target part of a target object, so as to collect a pulse wave signal of the target object; Controller for: In response to a blood pressure measurement instruction, controlling the wearable sensor to apply pressure to the target object, while receiving a pulse wave signal from the wearable sensor, until the pressure satisfies a first predetermined condition, and generating a pulse wave oscillation curve, wherein the pulse wave oscillation curve includes N pulse pulses formed by the pulse wave signal, where N is a positive integer greater than 1; Determining amplitude information of each of the N pulse pulses and time information corresponding to the amplitude information; generating a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve according to the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information; Generating continuous pulsating blood pressure information corresponding to the N pulse pulses according to the amplitude information of the pulse wave oscillation curve envelope; Wherein, the amplitude information of the pulse wave oscillation curve envelope includes the maximum amplitude of the pulse wave oscillation curve envelope; the generating of the continuous pulsating blood pressure information corresponding to the N pulse pulses according to the amplitude information of the pulse wave oscillation curve envelope includes: determining the average blood pressure information of the target object according to the maximum amplitude of the pulse wave oscillation curve envelope; calculating the diastolic pressure information corresponding to the average blood pressure information according to the average blood pressure information and a predetermined diastolic pressure coefficient; calculating the systolic pressure information corresponding to the average blood pressure information according to the average blood pressure information and a predetermined systolic pressure coefficient; obtaining the continuous pulsating blood pressure information according to the diastolic pressure information and the systolic pressure information; Wherein, the obtaining of the continuous pulsating blood pressure information according to the diastolic pressure information and the systolic pressure information includes: generating the Nth instantaneous pressure information corresponding to the Nth pulse pulse according to the shape feature increment information, the blood pressure increment information and the N-1th instantaneous pressure information corresponding to the N-1th pulse pulse, wherein the shape feature increment information is generated according to the predetermined system constants and shape feature error information corresponding to the shape feature information, the shape feature error information is generated according to the amplitude information and the pulsation period of the pulse pulse, the blood pressure increment information is generated according to the predetermined system constants corresponding to the pulse wave fluctuation signal and the pulse wave fluctuation signal, the pulse wave fluctuation signal is generated according to the pulse wave signal and the filtered pulse wave signal, the filtered pulse wave signal is obtained by filtering the pulse wave signal, and the instantaneous pressure information is used to characterize the pressure exerted by the wearable sensor on the target object when collecting the pulse pulse. The instant average pressure added; the pulsation coefficient is determined according to the maximum amplitude and the minimum amplitude of the diastolic pressure information, the systolic pressure information and the pulsating blood pressure information corresponding to the first pulse pulse; the hydrostatic pressure difference information corresponding to the target object is generated according to the blood density information, the gravitational acceleration information and the height difference information of the target object, wherein the gravitational acceleration information is determined according to the geographical location of the target object, and the height difference information represents the vertical height difference between the heart and the finger of the target object; the continuous pulsating blood pressure information is generated according to the Nth instant pressure information, the pulsation coefficient, the pulsating blood pressure information and the hydrostatic pressure difference information, wherein the pulsating blood pressure information is obtained according to a pre-constructed transfer function and the pressure pulsation information in the pressure information, the pressure pulsation information is the force information generated in response to the pulsation of the target object, and the transfer function represents the correlation between the pulsating blood pressure information and the pressure pulsation information.

2. The device according to claim 1, wherein: The controller includes a control module, a motor drive module, a motor, a pressure sensor and a syringe, and the wearable sensor includes a liquid capsule; The control module is used to send a control signal to the motor drive module in response to the blood pressure measurement instruction; The motor driving module is used to output a driving pulse corresponding to the control signal to the motor; The motor is connected to a screw nut arranged in the piston of the syringe through a screw, and the injection head of the syringe is located inside the liquid capsule; The motor is used to rotate the lead screw according to the driving pulse to control the extension and retraction of the lead screw nut, thereby driving the piston to move, so as to adjust the volume of liquid inside the liquid bag by changing the volume of liquid inside the syringe, thereby controlling the pressure applied by the liquid bag to the target object.

3. The device according to claim 2, wherein: The controller also includes a limit switch; Wherein, when the piston is at the target position, the limit switch is closed so as to send a limit signal to the control module via a closed loop corresponding to the limit switch, so that the control module stops sending the control signal to the motor drive module; When the piston is not in the target position, the limit switch is disconnected. When the limit switch is disconnected, the control module is also used to count the drive pulses, generate pulse quantity information, and determine that the pressure satisfies the first predetermined condition when the pulse quantity information satisfies the second predetermined condition.

4. The device according to claim 2, wherein: The controller also includes a pressure sensor and an analog-to-digital converter; The first end of the pressure sensor is connected to the liquid capsule and is used to collect information about the pressure applied by the liquid capsule to the target object, wherein the collected pressure information is in the form of an analog signal; The first end of the analog-to-digital converter is electrically connected to the second end of the pressure sensor, and the second end of the analog-to-digital converter is electrically connected to the control module. The analog-to-digital converter is used to process the pressure information in the form of an analog signal into pressure information in the form of a digital signal, and send the pressure information in the form of a digital signal to the control module.

5. A wearable non-invasive continuous blood pressure monitoring method, comprising: In response to a blood pressure measurement instruction, control the wearable sensor to apply pressure to the target object, and simultaneously receive a pulse wave signal from the wearable sensor until the pressure satisfies a first predetermined condition, and generate a pulse wave oscillation curve, wherein the pulse wave oscillation curve includes N pulse pulses formed by the pulse wave signal, and N is a positive integer greater than 1; Determining amplitude information of each of the N pulse pulses and time information corresponding to the amplitude information; generating a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve according to the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information; Generating continuous pulsating blood pressure information corresponding to the N pulse pulses according to the amplitude information of the pulse wave oscillation curve envelope; Wherein, the amplitude information of the pulse wave oscillation curve envelope includes the maximum amplitude of the pulse wave oscillation curve envelope; the generating of the continuous pulsating blood pressure information corresponding to the N pulse pulses according to the amplitude information of the pulse wave oscillation curve envelope includes: determining the average blood pressure information of the target object according to the maximum amplitude of the pulse wave oscillation curve envelope; calculating the diastolic pressure information corresponding to the average blood pressure information according to the average blood pressure information and a predetermined diastolic pressure coefficient; calculating the systolic pressure information corresponding to the average blood pressure information according to the average blood pressure information and a predetermined systolic pressure coefficient; obtaining the continuous pulsating blood pressure information according to the diastolic pressure information and the systolic pressure information; Wherein, the obtaining of the continuous pulsating blood pressure information according to the diastolic pressure information and the systolic pressure information includes: generating the Nth instantaneous pressure information corresponding to the Nth pulse pulse according to the shape feature increment information, the blood pressure increment information and the N-1th instantaneous pressure information corresponding to the N-1th pulse pulse, wherein the shape feature increment information is generated according to the predetermined system constants and shape feature error information corresponding to the shape feature information, the shape feature error information is generated according to the amplitude information and the pulsation period of the pulse pulse, the blood pressure increment information is generated according to the predetermined system constants corresponding to the pulse wave fluctuation signal and the pulse wave fluctuation signal, the pulse wave fluctuation signal is generated according to the pulse wave signal and the filtered pulse wave signal, the filtered pulse wave signal is obtained by filtering the pulse wave signal, and the instantaneous pressure information is used to characterize the pressure exerted by the wearable sensor on the target object when collecting the pulse pulse. The instant average pressure added; the pulsation coefficient is determined according to the maximum amplitude and the minimum amplitude of the diastolic pressure information, the systolic pressure information and the pulsating blood pressure information corresponding to the first pulse pulse; the hydrostatic pressure difference information corresponding to the target object is generated according to the blood density information, the gravitational acceleration information and the height difference information of the target object, wherein the gravitational acceleration information is determined according to the geographical location of the target object, and the height difference information represents the vertical height difference between the heart and the finger of the target object; the continuous pulsating blood pressure information is generated according to the Nth instant pressure information, the pulsation coefficient, the pulsating blood pressure information and the hydrostatic pressure difference information, wherein the pulsating blood pressure information is obtained according to a pre-constructed transfer function and the pressure pulsation information in the pressure information, the pressure pulsation information is the force information generated in response to the pulsation of the target object, and the transfer function represents the correlation between the pulsating blood pressure information and the pressure pulsation information.

6. The method according to claim 5, wherein: The pulse wave signal includes Q signal values, the pulse wave signal is collected in the Mth time period, and Q and M are both positive integers; The determining of the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information comprises: Generate a first-order difference value corresponding to the qth signal according to the qth signal value and the q-1th signal value among the Q signal values, where q is a positive integer greater than 1 and less than or equal to Q; generating a first-order difference signal corresponding to the pulse wave signal according to the first-order difference values ​​corresponding to Q-1 signal values; Calculate the differential threshold corresponding to the Mth time period according to the first-order differential values ​​corresponding to the Q-1 signal values ​​and a predetermined threshold coefficient; According to the differential threshold corresponding to the Mth time period, determining the differential peak points and J differential zero-crossing points corresponding to the N pulse pulses from the first-order differential signal, where J is a positive integer greater than 1; According to the relative order relationship between the pulse pulse corresponding to the differential peak point and the pulse pulse corresponding to the J differential zero-crossing points, the maximum peak point and the minimum valley point in the pulse wave oscillation curve are determined from the J differential zero-crossing points; According to the maximum peak point and the minimum valley point, amplitude information of each of the N pulse pulses and time information corresponding to the amplitude information are generated.

7. The method according to claim 5, wherein: The step of generating a pulse wave oscillation curve envelope corresponding to the pulse wave oscillation curve according to the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information comprises: Inputting the amplitude information of each of the N pulse pulses and the time information corresponding to the amplitude information into a first predetermined function, and fitting to obtain fitting parameters of the first predetermined function; Inputting the fitting parameters into a second predetermined function to calculate Gaussian parameters; The pulse wave oscillation curve envelope is obtained according to the Gaussian parameters and the Gaussian function.

8. The method according to claim 5, wherein: The method further comprises: Inputting the sample pulse wave signal and the first sample pressure pulsation information into a target cross-correlation function, and outputting phase delay information; In the case where the phase delay information does not satisfy the third predetermined condition, second sample pressure pulsation information having a phase difference from the first sample pressure pulsation information is input into the target cross-correlation function, until, in the case where the phase delay information satisfies the third predetermined condition, sample pressure pulsation information corresponding to the phase delay information satisfying the third predetermined condition is determined as target sample pressure pulsation information, wherein the target cross-correlation function is used to characterize the phase relationship between the sample pressure pulsation information and the sample pulse wave signal; generating normalized sample pressure pulsation information and a normalized sample pulse wave signal according to the target sample pressure pulsation information and the sample pulse wave signal; According to a predetermined frequency, the normalized sample pressure pulsation information and the normalized sample pulse wave signal are sampled respectively to obtain K pressure pulsation amplitudes corresponding to the sample pressure pulsation information and K pulsating blood pressure amplitudes corresponding to the sample pulse wave signal, wherein the kth pressure pulsation amplitude of the K pressure pulsation amplitudes and the kth pulsating blood pressure amplitude of the K pulsating blood pressure amplitudes both correspond to the kth sampling moment of the K sampling moments, K is a positive integer greater than 1, and k is a positive integer less than or equal to K; Inputting the information of the K pressure pulsation amplitudes and the K sampling moments into an initial transfer function, and outputting K predicted pulsating blood pressure amplitudes corresponding to the K sampling moments; Processing the K predicted pulsating blood pressure amplitudes and the K pulsating blood pressure amplitudes using a pre-constructed loss function, and outputting loss information; The function parameters of the initial transfer function are adjusted until the loss information satisfies a fourth predetermined condition, thereby obtaining the pre-constructed transfer function.

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