Servo value calibration method and calibration system based on volume compensation method blood pressure measurement

Abstract

The present disclosure provides a calibration method and a calibration system for a servo value of blood pressure measurement based on a volume compensation method. The calibration method comprises: within a predetermined pressure acquisition period, a wearable sensor worn by a measured object is driven by a motor to sequentially apply multiple initial pressures to the measured object, and multiple blood pressure values ​​and photoplethysmography signals of the measured object are acquired; based on the multiple blood pressure values, an initial average blood pressure of the measured object is calculated; based on the multiple initial pressures, multiple AC signal amplitudes corresponding to the multiple initial pressures are determined from the photoplethysmography signal; when the magnitude relationship between the multiple AC signal amplitudes satisfies a first predetermined condition, the multiple initial pressures are calibrated based on the initial average blood pressure and a predetermined pulse pressure difference to obtain multiple target pressures corresponding to the multiple initial pressures; and a target servo value is obtained based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures.

Description

Technical Field

[0001] The present disclosure relates to the technical field of continuous blood pressure measurement, and more specifically, to a calibration method and a calibration system for a servo value of blood pressure measurement based on a volume compensation method. Background Art

[0002] Blood pressure can not only effectively reflect the heart's pumping function, blood flow speed and peripheral vascular resistance, but is also an important indicator in the medical field. Whether in the monitoring and management of hypertension or hypotension, blood pressure measurement is a basic and key means. Therefore, continuous and accurate blood pressure measurement plays an important role in the medical field.

[0003] Volume compensation is a non-invasive continuous blood pressure measurement technology that drives the wearable sensor worn by the subject through a motor, so that the pressure applied by the wearable sensor to the subject at any time is consistent with the blood vessel pressure of the subject. However, factors such as body temperature, nerves and drugs can cause the contraction or relaxation of smooth muscles in blood vessels. This change can cause the current servo value of the motor to deviate from the correct value. It takes more than 30 seconds to re-determine the servo value. The servo value obtained over a long period of time may be delayed or inaccurate, which in turn affects the accuracy of blood pressure measurement. Summary of the invention

[0004] In order to solve at least one of the technical problems in the prior art, an embodiment of the present disclosure provides a calibration method and a calibration system for a servo value of blood pressure measurement based on a volume compensation method, which can shorten the time to obtain a target servo value and improve the accuracy of blood pressure measurement.

[0005] The embodiment of the present disclosure provides a method for calibrating a servo value of blood pressure measurement based on a volume compensation method, the calibration method comprising: within a predetermined pressure acquisition period, a wearable sensor worn by a measured object is driven by a motor to sequentially apply multiple initial pressures to the measured object, and multiple blood pressure values ​​and photoplethysmography signals of the measured object are collected, wherein the multiple initial pressures correspond to the multiple blood pressure values ​​one by one; based on the multiple blood pressure values, an initial average blood pressure of the measured object is calculated; based on the multiple initial pressures, multiple AC signal amplitudes corresponding to the multiple initial pressures are determined from the photoplethysmography signal; when the magnitude relationship between the multiple AC signal amplitudes meets a first predetermined condition, the multiple initial pressures are calibrated based on the initial average blood pressure and a predetermined pulse pressure difference to obtain multiple target pressures corresponding to the multiple initial pressures; based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures, a target servo value is obtained, so as to use the target servo value to control the motor to apply pressure matching the vascular pressure of the measured object to the measured object.

[0006] According to some embodiments of the present disclosure, in the case where the size relationship between the amplitudes of the above-mentioned multiple AC signals satisfies the first predetermined condition, the above-mentioned multiple initial pressures are calibrated based on the above-mentioned initial average blood pressure and the predetermined pulse pressure difference, and the multiple target pressures corresponding to the above-mentioned multiple initial pressures are obtained, including: in the case where the size relationship between the amplitudes of the above-mentioned multiple AC signals satisfies the above-mentioned first predetermined condition, based on the above-mentioned multiple initial pressures, generating pressure interval information; based on the above-mentioned pressure interval information, the above-mentioned initial average blood pressure and the above-mentioned predetermined pulse pressure difference, updating the above-mentioned multiple initial pressures to obtain the above-mentioned multiple target pressures corresponding to the above-mentioned multiple initial pressures.

[0007] According to some embodiments of the present disclosure, the above-mentioned multiple initial pressures include at least a first initial pressure, a second initial pressure and a third initial pressure, the above-mentioned first initial pressure is smaller than the above-mentioned second initial pressure, the above-mentioned second initial pressure is smaller than the above-mentioned third initial pressure, the above-mentioned multiple AC signal amplitudes include at least a first AC signal amplitude corresponding to the above-mentioned first initial pressure, a second AC signal amplitude corresponding to the above-mentioned second initial pressure and a third AC signal amplitude corresponding to the above-mentioned third initial pressure, and when the magnitude relationship between the above-mentioned multiple AC signal amplitudes satisfies the above-mentioned first predetermined condition, generating pressure interval information based on the above-mentioned multiple initial pressures includes: when the above-mentioned second AC signal amplitude is greater than the above-mentioned third AC signal amplitude and the above-mentioned second AC signal amplitude is smaller than the above-mentioned first AC signal amplitude, taking the above-mentioned first initial pressure as the lower limit of the interval and taking the above-mentioned second initial pressure as the upper limit of the interval to generate the above-mentioned pressure interval information; or, taking the minimum value of the above-mentioned initial average blood pressure as the lower limit of the interval and taking the above-mentioned first initial pressure as the upper limit of the interval to generate the above-mentioned pressure interval information.

[0008] According to some embodiments of the present disclosure, when the magnitude relationship between the amplitudes of the above-mentioned multiple AC signals satisfies the above-mentioned first predetermined condition, generating the pressure interval information based on the above-mentioned multiple initial pressures also includes: when the amplitude of the above-mentioned second AC signal is greater than the amplitude of the above-mentioned first AC signal and the amplitude of the above-mentioned second AC signal is less than the amplitude of the above-mentioned third AC signal, using the above-mentioned second initial pressure as the lower limit of the interval and the above-mentioned third initial pressure as the upper limit of the interval to generate the above-mentioned pressure interval information; or, using the above-mentioned third initial pressure as the lower limit of the interval and the maximum value of the above-mentioned initial average blood pressure as the upper limit of the interval to generate the above-mentioned pressure interval information.

[0009] According to some embodiments of the present disclosure, the above-mentioned multiple initial pressures are updated based on the above-mentioned pressure interval information, the above-mentioned initial average blood pressure and the above-mentioned predetermined pulse pressure difference to obtain the above-mentioned multiple target pressures corresponding to the above-mentioned multiple initial pressures, including: comparing the above-mentioned pressure interval information with the above-mentioned initial average blood pressure, and when the above-mentioned initial average blood pressure is greater than the maximum value of the above-mentioned pressure interval information, the above-mentioned first initial pressure, the above-mentioned second initial pressure and the above-mentioned third initial pressure are respectively updated to the first target pressure, the second target pressure and the third target pressure, wherein the above-mentioned first target pressure is determined based on the above-mentioned first initial pressure and the above-mentioned predetermined pulse pressure difference, the above-mentioned second target pressure is determined based on the above-mentioned first initial pressure, and the above-mentioned third target pressure is determined based on the above-mentioned second initial pressure; when the above-mentioned initial average blood pressure is less than the minimum value of the above-mentioned pressure interval information, the above-mentioned first initial pressure, the above-mentioned second initial pressure and the above-mentioned third initial pressure are respectively updated to the fourth target pressure, the fifth target pressure and the sixth target pressure, wherein the above-mentioned fourth target pressure is determined based on the above-mentioned second initial pressure, the above-mentioned fifth target pressure is determined based on the above-mentioned third initial pressure, and the above-mentioned sixth target pressure is determined based on the above-mentioned third initial pressure and the above-mentioned predetermined pulse pressure difference.

[0010] According to some embodiments of the present disclosure, obtaining the target servo value based on the above-mentioned multiple target pressures and the multiple AC signal amplitudes corresponding to the above-mentioned multiple target pressures includes: obtaining the target average blood pressure based on the above-mentioned multiple target pressures and the multiple AC signal amplitudes corresponding to the above-mentioned multiple target pressures; obtaining the above-mentioned target servo value based on the above-mentioned target average blood pressure.

[0011] According to some embodiments of the present disclosure, obtaining the target average blood pressure based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures includes: inputting the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures into a function to be fitted, and fitting to obtain fitting parameters of the function to be fitted; and determining the target average blood pressure based on the fitting parameters.

[0012] According to some embodiments of the present disclosure, obtaining the target servo value based on the target average blood pressure includes: acquiring the DC component of the target average blood pressure from the photoplethysmography signal; calculating the average value of the DC component of the target average blood pressure; and determining the average value as the target servo value.

[0013] According to some embodiments of the present disclosure, obtaining the target servo value based on the target average blood pressure also includes: determining the AC signal amplitude of the target average blood pressure from the photoplethysmography signal; and obtaining the target servo value based on the AC signal amplitude of the target average blood pressure.

[0014] According to some embodiments of another aspect of the present disclosure, a calibration system for a servo value of blood pressure measurement based on a volume compensation method is provided, which is suitable for implementing the above-mentioned calibration method, wherein the above-mentioned calibration system includes: an acquisition module, which is used to acquire multiple blood pressure values ​​and photoplethysmographic signals of a measured object within a predetermined pressure acquisition period; a calculation module, which is used to calculate the initial average blood pressure of the measured object based on the above-mentioned multiple blood pressure values; a determination module, which is used to determine multiple AC signal amplitudes corresponding to the above-mentioned multiple initial pressures from the photoplethysmographic signals based on the multiple initial pressures; a calibration module, which is used to calibrate the above-mentioned multiple initial pressures based on the above-mentioned initial average blood pressure and a predetermined pulse pressure difference when the size relationship between the above-mentioned multiple AC signal amplitudes meets a first predetermined condition, so as to obtain multiple target pressures corresponding to the above-mentioned multiple initial pressures; and a control module, which is used to obtain a target servo value based on the above-mentioned multiple target pressures and the multiple AC signal amplitudes corresponding to the above-mentioned multiple target pressures, so as to apply a pressure matching the vascular pressure of the above-mentioned measured object to the above-mentioned measured object using the above-mentioned target servo value.

[0015] According to a calibration method and calibration system for a servo value of blood pressure measurement based on a volume compensation method according to an embodiment of the present disclosure, within a predetermined pressure acquisition period, a wearable sensor worn by a measured object is driven by a motor to sequentially apply multiple initial pressures to the measured object, and multiple blood pressure values ​​and photoplethysmographic signals of the measured object are acquired, wherein the multiple initial pressures correspond to the multiple blood pressure values ​​one by one; based on the multiple blood pressure values, the initial average blood pressure of the measured object is calculated; based on the multiple initial pressures, multiple AC signal amplitudes corresponding to the multiple initial pressures are determined from the photoplethysmographic signals; when the magnitude relationship between the multiple AC signal amplitudes meets a first predetermined condition, the multiple initial pressures are calibrated based on the initial average blood pressure and a predetermined pulse pressure difference to obtain multiple target pressures corresponding to the multiple initial pressures; based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures, a target servo value is obtained, which can shorten the time for obtaining the target servo value, and at the same time, the target servo value can be used to control the motor to apply a pressure matching the vascular pressure of the measured object to the measured object, thereby improving the accuracy of blood pressure measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, 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:

[0017] Figure 1 is a flow chart of a method for calibrating a servo value of blood pressure measurement based on a volume compensation method according to an exemplary embodiment of the present disclosure;

[0018] Figure 2is a system block diagram of blood pressure measurement based on a volume compensation method according to an illustrative embodiment of the present disclosure;

[0019] Figure 3 is a graph of a cuff pressure and a photoplethysmographic signal determined based on a volume oscillometric method according to an illustrative embodiment of the present disclosure;

[0020] Figure 4 is a waveform diagram of the Gaussian function relationship between the amplitude of the AC signal of the photoplethysmography signal and the change of the cuff pressure according to an exemplary embodiment of the present disclosure;

[0021] Figure 5 is a flowchart of sub-steps of calibrating multiple initial pressures to obtain multiple target pressures corresponding to the multiple initial pressures according to an exemplary embodiment of the present disclosure;

[0022] Figure 6 is a waveform diagram of a cuff pressure and a photoplethysmography signal determined based on a volume compensation method according to an illustrative embodiment of the present disclosure;

[0023] Figure 7 is a flowchart of sub-steps of obtaining a target servo value based on a plurality of target pressures and a plurality of AC signal amplitudes corresponding to the plurality of target pressures according to an exemplary embodiment of the present disclosure;

[0024] Figure 8 is a flowchart of sub-steps of obtaining a target average blood pressure based on multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures according to an exemplary embodiment of the present disclosure;

[0025] Fig. 9 is a flowchart of sub-steps of obtaining a target servo value based on a target average blood pressure according to an illustrative embodiment of the present disclosure;

[0026] Fig.10 is a flowchart of sub-steps of obtaining a target servo value based on a target average blood pressure according to another exemplary embodiment of the present disclosure;

[0027] Fig.11 is a block diagram of a calibration system for a servo value of blood pressure measurement based on a volume compensation method according to an exemplary embodiment of the present disclosure;

[0028] Fig.12 4 is a block diagram of an electronic device for a method for calibrating a servo value of blood pressure measurement based on a volume compensation method according to an exemplary embodiment of the present disclosure.

[0029] In the drawings, the meanings of the reference numerals are as follows:

[0030] 1. Air pump;

[0031] 2. Proportional valve;

[0032] 3. Wearable sensors;

[0033] 4. Controller;

[0034] 5. Driving circuit;

[0035] 6. Pressure sensor;

[0036] 7. Signal acquisition module;

[0037] 8. Analog-to-digital converter. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.).

[0042] In order to solve the problem of inaccurate blood pressure measurement, according to the inventive concept of one aspect of the present disclosure, within a predetermined pressure collection period, a wearable sensor worn by a measured object is driven by a motor to sequentially apply multiple initial pressures to the measured object, and multiple blood pressure values ​​and photoplethysmography signals of the measured object are collected, and the multiple initial pressures correspond to the multiple blood pressure values ​​one by one; based on the multiple blood pressure values, the initial average blood pressure of the measured object is calculated; based on the multiple initial pressures, multiple AC signal amplitudes corresponding to the multiple initial pressures are determined from the photoplethysmography signal; when the magnitude relationship between the multiple AC signal amplitudes meets a first predetermined condition, the multiple initial pressures are calibrated based on the initial average blood pressure and a predetermined pulse pressure difference to obtain multiple target pressures corresponding to the multiple initial pressures; based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures, a target servo value is obtained, which can shorten the time for obtaining the target servo value, and at the same time, the target servo value can be used to control the motor to apply a pressure matching the vascular pressure of the measured object to the measured object, thereby improving the accuracy of blood pressure measurement.

[0043] Figure 1 The present invention is a flowchart of a method for calibrating a servo value of blood pressure measurement based on a volume compensation method according to an exemplary embodiment of the present invention.

[0044] According to the embodiments of the present disclosure, Figure 1 As shown, a method for calibrating a servo value of blood pressure measurement based on a volume compensation method is provided, comprising the following steps S1 to S5.

[0045] Step S1: within a predetermined pressure collection period, a wearable sensor worn by the measured object is driven by a motor to sequentially apply multiple initial pressures to the measured object, and multiple blood pressure values ​​and photoplethysmography signals of the measured object are collected.

[0046] According to an embodiment of the present disclosure, there is a one-to-one correspondence between the multiple initial pressures and the multiple blood pressure values.

[0047] According to an embodiment of the present disclosure, the predetermined pressure collection period may be 10 blood pressure beats, 20 blood pressure beats, 30 blood pressure beats, ..., 100 blood pressure beats.

[0048] Figure 2 4 is a system block diagram of blood pressure measurement based on volume compensation method according to an illustrative embodiment of the present disclosure.

[0049] In an illustrative embodiment, Figure 2As shown, the wearable sensor 3 can be set in the form of an airbag bandage or an airbag finger sleeve. The wearable sensor 3 can be worn on the finger of the object being measured. The wearable sensor 3 includes an LED light and a photoelectric sensor. The photoelectric sensor can select a photodiode. The controller 4 controls the drive circuit 5, the pressure sensor 6 and the signal acquisition module 7. The controller 4 can be a microcontroller (MCU controller). The drive circuit 5 drives the air pump 1. The air pump 1 controls the airbag of the wearable sensor 3 to be inflated or deflated through the proportional valve 2 to apply pressure to the finger. The pressure sensor 6 collects the blood pressure value by measuring the pressure change in the blood vessels of the finger. When the heart beats, the blood flow will produce pressure on the blood vessel wall. The pressure sensor 6 can detect this pressure change. The controller 4 converts it into an electrical signal through the analog-to-digital converter 8 and analyzes these electrical signals, so that the systolic pressure and the diastolic pressure can be calculated to obtain the blood pressure value reading of the finger artery. The signal acquisition module 7 is used to collect the photoelectric volumetric recording signal of the finger artery.

[0050] According to the embodiment of the present disclosure, the volume compensation method is to apply initial pressure to the object under test at any time through a wearable sensor, so that the vascular pressure of the object under test is consistent with the initial pressure. At this time, the diameter of the vascular wall will not change due to blood pressure fluctuations, but will be maintained in a fixed volume state, that is, a no-load state. In this state, the initial pressure applied externally is equal to the vascular pressure, so the pressure difference (transmural pressure) between the cuff pressure of the wearable sensor and the pressure in the finger artery is zero, which can achieve accurate non-invasive blood pressure measurement.

[0051] According to the embodiment of the present disclosure, the blood pressure measurement based on the volume compensation method is mainly divided into two stages, one stage is an open loop stage, and the other stage is a closed loop stage. Step S1 is the open loop stage, and the open loop stage is to find the reference value of the servo control in the closed loop stage, that is, the blood vessel volume V0 under the no-load state. If the blood vessel volume V0 under the no-load state is determined using the volume oscillometric method, the pressure in the airbag (P C ), and determine the DC signal corresponding to the maximum pressure of the AC signal amplitude of the photoplethysmography signal (PPG) as the target servo value. Steps S2 to S5 are the closed-loop stage, and the continuous blood pressure monitoring in the closed-loop stage is achieved by high-speed servo control based on the servo set value determined in the open-loop stage.

[0052] Figure 3 is a graph of cuff pressure and photoplethysmographic signals determined based on plethysmography according to an illustrative embodiment of the present disclosure.

[0053] According to the embodiments of the present disclosure, Figure 3As shown, during the uniform increase of the cuff pressure, the AC signal amplitude of the photoplethysmography signal is the largest at the initial average blood pressure P_MAP, and the AC signal amplitude gradually decreases at both ends of the initial average blood pressure P_MAP.

[0054] Figure 4 It is a waveform diagram of the Gaussian function relationship between the AC signal amplitude of the photoplethysmography signal and the change of the finger cuff pressure according to an exemplary embodiment of the present disclosure.

[0055] According to the embodiments of the present disclosure, Figure 4 As shown, the AC signal amplitude of the photoplethysmography signal presents a single peak value as the cuff pressure increases and is a Gaussian function relationship with symmetrical characteristics. When the cuff pressure is the initial average blood pressure P_MAP, the AC signal amplitude of the photoplethysmography signal is the largest, and the corresponding DC component of the photoplethysmography signal is the target servo value.

[0056] Step S2: Calculate the initial average blood pressure of the subject based on the multiple blood pressure values.

[0057] According to an embodiment of the present disclosure, based on the continuous blood pressure waveform, a calibration time is first set, and then the blood pressure values ​​of three blood pressure beats before the calibration time are selected, and the average of the three blood pressure values ​​is calculated as the initial average blood pressure P_MAP.

[0058] In an illustrative embodiment, if the 10th blood pressure beat is selected as the calibration moment, the average of the blood pressure value of the 7th blood pressure beat, the blood pressure value of the 8th blood pressure beat and the blood pressure value of the 9th blood pressure beat is calculated as the initial average blood pressure P_MAP.

[0059] Step S3: Based on the multiple initial pressures, determine multiple AC signal amplitudes corresponding to the multiple initial pressures from the photoplethysmography signal.

[0060] Step S4: When the magnitude relationship between the amplitudes of the multiple AC signals satisfies the first predetermined condition, the multiple initial pressures are calibrated based on the initial average blood pressure and the predetermined pulse pressure difference to obtain multiple target pressures corresponding to the multiple initial pressures.

[0061] Step S5: Based on multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures, a target servo value is obtained, so as to use the target servo value to control the motor to apply a pressure matching the blood vessel pressure of the measured object to the measured object.

[0062] According to an embodiment of the present disclosure, within a predetermined pressure collection period, a wearable sensor worn by a measured object is driven by a motor to sequentially apply multiple initial pressures to the measured object, and multiple blood pressure values ​​and photoplethysmography signals of the measured object are collected, and the multiple initial pressures correspond to the multiple blood pressure values ​​one by one; based on the multiple blood pressure values, the initial average blood pressure of the measured object is calculated; based on the multiple initial pressures, multiple AC signal amplitudes corresponding to the multiple initial pressures are determined from the photoplethysmography signal; when the magnitude relationship between the multiple AC signal amplitudes meets the first predetermined condition, the multiple initial pressures are calibrated based on the initial average blood pressure and the predetermined pulse pressure difference to obtain multiple target pressures corresponding to the multiple initial pressures; based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures, a target servo value is obtained, which can shorten the time for obtaining the target servo value, and at the same time, the target servo value can be used to control the motor to apply a pressure matching the vascular pressure of the measured object to the measured object, thereby improving the accuracy of blood pressure measurement.

[0063] Figure 5 It is a flowchart of sub-steps of calibrating multiple initial pressures to obtain multiple target pressures corresponding to the multiple initial pressures according to an exemplary embodiment of the present disclosure.

[0064] According to the embodiments of the present disclosure, Figure 5 As shown, when the magnitude relationship between the amplitudes of multiple AC signals satisfies the first predetermined condition, multiple initial pressures are calibrated based on the initial average blood pressure and the predetermined pulse pressure difference, and multiple target pressures corresponding to the multiple initial pressures are obtained, including the following steps S40-S41.

[0065] Step S40: When the magnitude relationship between the multiple AC signal amplitudes satisfies the first predetermined condition, pressure interval information is generated based on the multiple initial pressures.

[0066] According to an embodiment of the present disclosure, the multiple initial pressures include at least a first initial pressure, a second initial pressure, and a third initial pressure, the first initial pressure is less than the second initial pressure, the second initial pressure is less than the third initial pressure, the multiple AC signal amplitudes include at least a first AC signal amplitude corresponding to the first initial pressure, a second AC signal amplitude corresponding to the second initial pressure, and a third AC signal amplitude corresponding to the third initial pressure, and when the magnitude relationship between the multiple AC signal amplitudes satisfies the first predetermined condition, based on the multiple initial pressures, generating pressure interval information includes: when the second AC signal amplitude is greater than the third AC signal amplitude and the second AC signal amplitude is less than the first AC signal amplitude, using the first initial pressure as the interval lower limit and the second initial pressure as the interval upper limit to generate pressure interval information. Alternatively, using the minimum value of the initial average blood pressure as the interval lower limit and the first initial pressure as the interval upper limit to generate pressure interval information.

[0067] Figure 6 is a waveform diagram of a finger cuff pressure and a photoplethysmography signal determined based on a volume compensation method according to an illustrative embodiment of the present disclosure.

[0068] According to the embodiments of the present disclosure, Figure 6 As shown, PID control of pressure is performed, and the multiple initial pressures at least include a first initial pressure P1, a second initial pressure P2, and a third initial pressure P3. The second initial pressure P2 can be expressed by the following formula (1):

[0069] P2=P_MAP(1).

[0070] According to an embodiment of the present disclosure, the first initial pressure P1 can be expressed by the following formula (2):

[0071] P1=P2-ΔP(2).

[0072] According to an embodiment of the present disclosure, the third initial pressure P3 can be expressed by the following formula (3):

[0073] P3=P2+ΔP(3).

[0074] Among them, ΔP is determined according to the predetermined pulse pressure difference of the continuous blood pressure waveform, for example, 5 mmHg, to ensure that P1 and P3 are within the diastolic and systolic pressure ranges of the continuous blood pressure waveform. The initial average blood pressure P_MAP enters the PID control of pressure at half the diastolic amplitude of the continuous blood pressure waveform, while maintaining the cuff pressure at the first initial pressure P1, the second initial pressure P2 and the third initial pressure P3. The duration of each pressure interval is determined by the extracted photoplethysmographic signal waveform, and the next pressure gradient is switched at half the diastolic amplitude of the photoplethysmographic signal waveform of each blood pressure beat.

[0075] According to an embodiment of the present disclosure, the AC signal amplitude is the amplitude of the systolic period of each blood pressure beat, and the first AC signal amplitude V corresponding to the first initial pressure P1 is pp1 , the second AC signal amplitude V corresponding to the second initial pressure P2 pp2 and the third AC signal amplitude V corresponding to the third initial pressure P3 pp3 , assuming that the target mean blood pressure P_MAP new The AC signal amplitude of the photoplethysmographic signal under PPnew , when the amplitude of the second AC signal is greater than the amplitude of the third AC signal and the amplitude of the second AC signal is less than the amplitude of the first AC signal, it can be expressed by the following formula (4):

[0076] V pp1 >V pp2 >Vpp3 (4).

[0077] According to the embodiments of the present disclosure, according to Figure 4 , we can know the target mean blood pressure P_MAP new In the pressure interval [P1, P2] or in the pressure interval [0, P1].

[0078] According to an embodiment of the present disclosure, when the magnitude relationship between the amplitudes of multiple AC signals satisfies the first predetermined condition, generating pressure interval information based on multiple initial pressures further includes: when the amplitude of the second AC signal is greater than the amplitude of the first AC signal and the amplitude of the second AC signal is less than the amplitude of the third AC signal, using the second initial pressure as the lower limit of the interval and the third initial pressure as the upper limit of the interval to generate the pressure interval information. Alternatively, using the third initial pressure as the lower limit of the interval and the maximum value of the initial average blood pressure as the upper limit of the interval to generate the pressure interval information.

[0079] According to an embodiment of the present disclosure, when the amplitude of the second AC signal is greater than the amplitude of the first AC signal and the amplitude of the second AC signal is less than the amplitude of the third AC signal, it can be expressed by the following formula (5):

[0080] V pp3 >V pp2 >V pp1 (5).

[0081] According to the embodiments of the present disclosure, according to Figure 4 , we can know the target mean blood pressure P_MAP new In the pressure range [P2, P3] or in the pressure range [P3, P max ], P max is the maximum value of the initial average blood pressure, for example, 250 mmHg.

[0082] According to an embodiment of the present disclosure, when the amplitude of the first AC signal is greater than the amplitude of the third AC signal and the amplitude of the first AC signal is less than the amplitude of the second AC signal, it can be expressed by the following formula (6):

[0083] V pp2 >V pp1 >V pp3 (6).

[0084] According to the embodiments of the present disclosure, according to Figure 4 , we can know the target mean blood pressure P_MAP new In the pressure range [P1, P2].

[0085] According to an embodiment of the present disclosure, when the amplitude of the third AC signal is greater than the amplitude of the first AC signal and the amplitude of the third AC signal is less than the amplitude of the second AC signal, it can be expressed by the following formula (7):

[0086] V pp2 >V pp3 >V pp1 (7).

[0087] According to the embodiments of the present disclosure, according to Figure 4 , we can know the target mean blood pressure P_MAP new In the pressure range [P2, P3].

[0088] According to the embodiments of the present disclosure, based on the linear increasing relationship between the AC signal amplitude of the photoplethysmography signal and the cuff pressure, and using a Gaussian function model to describe its single peak and symmetric characteristics, during the continuous blood pressure measurement process in the closed-loop stage, the target servo value is obtained by setting three different pressure gradients. The calibration can be completed in as fast as four cardiac cycles. The cardiac cycle refers to the time required for the heart to complete a complete contraction and relaxation, which greatly shortens the calibration time.

[0089] Step S41: Based on the pressure interval information, the initial average blood pressure and the predetermined pulse pressure difference, multiple initial pressures are updated to obtain multiple target pressures corresponding to the multiple initial pressures.

[0090] According to an embodiment of the present disclosure, based on the pressure interval information, the initial average blood pressure and the predetermined pulse pressure difference, multiple initial pressures are updated to obtain multiple target pressures corresponding to the multiple initial pressures, including: comparing the pressure interval information with the initial average blood pressure, and when the initial average blood pressure is greater than the maximum value of the pressure interval information, the first initial pressure, the second initial pressure and the third initial pressure are respectively updated to the first target pressure, the second target pressure and the third target pressure. The first target pressure is determined based on the first initial pressure and the predetermined pulse pressure difference, the second target pressure is determined based on the first initial pressure, and the third target pressure is determined based on the second initial pressure. When the initial average blood pressure is less than the minimum value of the pressure interval information, the first initial pressure, the second initial pressure and the third initial pressure are respectively updated to the fourth target pressure, the fifth target pressure and the sixth target pressure. The fourth target pressure is determined based on the second initial pressure, the fifth target pressure is determined based on the third initial pressure, and the sixth target pressure is determined based on the third initial pressure and the predetermined pulse pressure difference.

[0091] According to an embodiment of the present disclosure, when the second AC signal amplitude is greater than the third AC signal amplitude and the second AC signal amplitude is less than the first AC signal amplitude, according to the target average blood pressure P_MAP new The target average blood pressure P_MAP can be known from the pressure range newis less than the initial average blood pressure P_MAP, the first initial pressure is updated to the first target pressure, the first target pressure is expressed as P1-ΔP, the second initial pressure is updated to the second target pressure, the second target pressure is expressed as P1, and the third initial pressure is updated to the third target pressure, the third target pressure is expressed as P2.

[0092] According to an embodiment of the present disclosure, when the second AC signal amplitude is greater than the first AC signal amplitude and the second AC signal amplitude is less than the third AC signal amplitude, according to the target average blood pressure P_MAP new The target average blood pressure P_MAP can be known from the pressure range new is greater than the initial average blood pressure P_MAP, the first initial pressure is updated to the fourth target pressure, the fourth target pressure is represented by P2, the second initial pressure is updated to the fifth target pressure, the fifth target pressure is represented by P3, and the third initial pressure is updated to the sixth target pressure, the sixth target pressure is represented by P3+ΔP.

[0093] According to an embodiment of the present disclosure, when the amplitude of the first AC signal is greater than the amplitude of the third AC signal and the amplitude of the first AC signal is less than the amplitude of the second AC signal, the first initial pressure, the second initial pressure and the third initial pressure are directly determined as target pressures corresponding to the first initial pressure, the second initial pressure and the third initial pressure, respectively.

[0094] According to an embodiment of the present disclosure, when the amplitude of the third AC signal is greater than the amplitude of the first AC signal and the amplitude of the third AC signal is less than the amplitude of the second AC signal, the first initial pressure, the second initial pressure and the third initial pressure are directly determined as target pressures corresponding to the first initial pressure, the second initial pressure and the third initial pressure, respectively.

[0095] According to an embodiment of the present disclosure, by acquiring the systolic amplitude of the blood pressure beat of each photoplethysmography signal under different initial pressures of the cuff and updating multiple initial pressures, multiple target pressures corresponding to the multiple initial pressures are obtained, and the target servo value can be accurately acquired in real time, thereby avoiding the hysteresis problem in obtaining the target servo value and ensuring the high accuracy and reliability of blood pressure measurement in the closed-loop stage.

[0096] Figure 7 The present invention is a flowchart of sub-steps of obtaining a target servo value based on a plurality of target pressures and a plurality of AC signal amplitudes corresponding to the plurality of target pressures according to an exemplary embodiment of the present invention.

[0097] According to the embodiments of the present disclosure, Figure 7 As shown, obtaining a target servo value based on a plurality of target pressures and a plurality of AC signal amplitudes corresponding to the plurality of target pressures includes the following steps S50 - S51 .

[0098] Step S50: obtaining a target average blood pressure based on multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures.

[0099] Figure 8 It is a flowchart of sub-steps of obtaining a target average blood pressure based on multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures according to an exemplary embodiment of the present disclosure.

[0100] According to the embodiments of the present disclosure, Figure 8 As shown, based on multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures, obtaining the target average blood pressure includes the following steps S501-S502.

[0101] Step S501: inputting a plurality of target pressures and a plurality of AC signal amplitudes corresponding to the plurality of target pressures into a function to be fitted, and fitting parameters of the function to be fitted are obtained by fitting.

[0102] Step S502: Determine the target mean blood pressure based on the fitting parameters.

[0103] According to an embodiment of the present disclosure, a set of discrete data points (x ) of the volume oscillometric waveform amplitude with respect to the pressure sequence can be obtained according to the finger cuff pressure and the AC signal amplitude of the photoplethysmographic signal. i ,y i ), i=1, 2, 3, where x i is the pressure sequence point of the glove, which are the first initial pressure P1, the second initial pressure P2 and the third initial pressure P3, y i are the AC signal amplitude points V of the photoplethysmographic signal corresponding to the first initial pressure P1, the second initial pressure P2 and the third initial pressure P3 respectively. pp1 、V pp2 and V pp3 , using the least squares Gaussian fitting method based on (x i ,y i ) constructs the oscilloscope waveform envelope, and the Gaussian function used is expressed as shown in the following formula (8):

[0104] (8).

[0105] According to an embodiment of the present disclosure, the first fitting parameter A, the second fitting parameter B and the third fitting parameter C in formula (8) can be calculated by the least square method, and the second fitting parameter B is determined as the target mean blood pressure P_MAP new .

[0106] According to an embodiment of the present disclosure, a set of discrete data points of volume oscillometric waveform amplitude with respect to the pressure sequence can be obtained based on the cuff pressure and the AC signal amplitude of the photoplethysmography signal. The target average blood pressure is obtained based on the discrete data point set using a least squares Gaussian fitting method, thereby ensuring the accuracy of the target servo value subsequently obtained based on the target average blood pressure.

[0107] Step S51: Obtain a target servo value based on the target average blood pressure.

[0108] Fig. 9 is a flowchart of sub-steps of obtaining a target servo value based on a target average blood pressure according to an exemplary embodiment of the present disclosure.

[0109] According to the embodiments of the present disclosure, Fig. 9 As shown, obtaining the target servo value based on the target average blood pressure includes the following steps S511 to S513.

[0110] Step S511: Obtain the DC component of the target mean blood pressure from the photoplethysmography signal.

[0111] Step S512: Calculate the average value of the DC component of the target average blood pressure.

[0112] According to an embodiment of the present disclosure, the average value of the DC component of the target average blood pressure is calculated by the following formula (9):

[0113] (9).

[0114] Where N represents the cuff pressure at the target mean blood pressure P_MAP new The signal length under V DC is the DC signal component of the target mean blood pressure.

[0115] Step S513: Determine the average value as the target servo value .

[0116] Fig.10 is a flowchart of sub-steps of obtaining a target servo value based on a target average blood pressure according to another exemplary embodiment of the present disclosure.

[0117] According to the embodiments of the present disclosure, Fig.10 As shown, based on the target average blood pressure, obtaining the target servo value also includes the following steps S514-S515.

[0118] Step S514: Determine the AC signal amplitude of the target mean blood pressure from the photoplethysmography signal.

[0119] Step S515: Obtain a target servo value based on the AC signal amplitude of the target average blood pressure.

[0120] According to an embodiment of the present disclosure, half of the AC signal amplitude of the target average blood pressure is taken to obtain the target servo value .

[0121] According to an embodiment of the present disclosure, the target servo value is obtained After that, the PID control of the servo value is entered. At this time, the servo value is , and wait for the next calibration.

[0122] According to an embodiment of the present disclosure, a target servo value is used to control a motor to apply a pressure matching the blood vessel pressure of the measured object to the measured object, thereby improving the accuracy of blood pressure measurement.

[0123] Fig.11 4 is a block diagram of a system for calibrating a servo value of blood pressure measurement based on a volume compensation method according to an exemplary embodiment of the present disclosure.

[0124] According to another aspect of the present disclosure, a calibration system for a servo value of blood pressure measurement based on a volume compensation method is provided, which is suitable for implementing the above calibration method, such as Fig.11 As shown, the calibration system 600 includes an acquisition module 610 , a calculation module 620 , a determination module 630 , a calibration module 640 and a control module 650 .

[0125] According to an embodiment of the present disclosure, the acquisition module 610 is used to collect multiple blood pressure values ​​and photoplethysmography signals of the subject within a predetermined pressure acquisition period. In one embodiment, the acquisition module 610 can be used to execute step S1 described above, which will not be repeated here.

[0126] According to an embodiment of the present disclosure, the calculation module 620 is used to calculate the initial average blood pressure of the subject based on multiple blood pressure values. In one embodiment, the calculation module 620 can be used to execute step S2 described above, which will not be repeated here.

[0127] According to an embodiment of the present disclosure, the determination module 630 is used to determine multiple AC signal amplitudes corresponding to multiple initial pressures from the photoplethysmography signal based on multiple initial pressures. In one embodiment, the determination module 630 can be used to execute step S3 described above, which will not be repeated here.

[0128] According to an embodiment of the present disclosure, the calibration module 640 is used to calibrate multiple initial pressures based on the initial average blood pressure and the predetermined pulse pressure difference when the size relationship between the amplitudes of multiple AC signals meets the first predetermined condition, so as to obtain multiple target pressures corresponding to the multiple initial pressures. In one embodiment, the calibration module 640 can be used to execute step S4 described above, which will not be repeated here.

[0129] According to an embodiment of the present disclosure, the control module 650 is used to obtain a target servo value based on multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures, so as to use the target servo value to apply a pressure matching the vascular pressure of the object under test to the object under test. In one embodiment, the control module 650 can be used to execute step S5 described above, which will not be repeated here.

[0130] According to an embodiment of the present disclosure, any multiple modules of the acquisition module 610, the calculation module 620, the determination module 630, the calibration module 640 and the control module 650 can be combined into one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present disclosure, at least one of the acquisition module 610, the calculation module 620, the determination module 630, the calibration module 640 and the control module 650 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation modes of software, hardware and firmware or in a suitable combination of any of them. Alternatively, at least one of the acquisition module 610 , the calculation module 620 , the determination module 630 , the calibration module 640 and the control module 650 may be at least partially implemented as a computer program module, and when the computer program module is executed, a corresponding function may be performed.

[0131] Fig.12 4 is a block diagram of an electronic device for a method for calibrating a servo value of blood pressure measurement based on a volume compensation method according to an exemplary embodiment of the present disclosure. Fig.12 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0132] like Fig.12As shown, the electronic device 700 according to an embodiment of the present disclosure includes a processor 701, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 702 or a program loaded from a storage part 708 to a random access memory (RAM) 703. The processor 701 may include, for example, a general-purpose microprocessor (such as a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (for example, an application-specific integrated circuit (ASIC)), etc. The processor 701 may also include an onboard memory for caching purposes. The processor 701 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0133] In RAM 703, various programs and data required for the operation of electronic device 700 are stored. Processor 701, ROM 702 and RAM 703 are connected to each other via bus 704. Processor 701 performs various operations of the method flow according to the embodiment of the present disclosure by executing the program in ROM 702 and / or RAM 703. It should be noted that the program can also be stored in one or more memories other than ROM 702 and RAM 703. Processor 701 can also perform various operations of the method flow according to the embodiment of the present disclosure by executing the program stored in the one or more memories.

[0134] According to an embodiment of the present disclosure, the electronic device 700 may further include an input / output (I / O) interface 705, which is also connected to the bus 704. The electronic device 700 may further include one or more of the following components connected to the input / output (I / O) interface 705: an input portion 706 including a keyboard, a mouse, etc.; an output portion 707 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 708 including a hard disk, etc.; and a communication portion 709 including a network interface card such as a LAN card, a modem, etc. The communication portion 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the input / output (I / O) interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 710 as needed, so that a computer program read therefrom is installed into the storage portion 708 as needed.

[0135] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the calibration method according to the embodiment of the present disclosure is implemented.

[0136] According to an embodiment of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, it may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device. For example, according to an embodiment of the present disclosure, the computer-readable storage medium may include the ROM 702 and / or RAM 703 described above and / or one or more memories other than ROM 702 and RAM 703.

[0137] The embodiment of the present disclosure also includes a computer program product, which includes a computer program, and the computer program contains program code for executing the method shown in the flowchart. When the computer program product is run in a computer system, the program code is used to enable the computer system to implement the method provided by the embodiment of the present disclosure.

[0138] The above functions defined in the system / device of the embodiment of the present disclosure are performed when the computer program is executed by the processor 701. According to the embodiment of the present disclosure, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0139] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 709, and / or installed from the removable medium 711. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0140] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 709, and / or installed from the removable medium 711. When the computer program is executed by the processor 701, the above functions defined in the system of the embodiment of the present disclosure are performed. According to the embodiment of the present disclosure, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0141] According to an embodiment of the present disclosure, the program code for executing the computer program provided by the embodiment of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0142] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0143] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0144] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure, and the shapes and sizes of the components in the drawings do not reflect the actual size and proportion, but only illustrate the contents of the embodiments of the present disclosure.

[0145] Unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can be changed according to the desired properties obtained by the content of the present disclosure. Specifically, 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. In general, the meaning of the expression is to include changes in some embodiments of ±10%, in some embodiments of ±5%, in some embodiments of ±1%, and in some embodiments of ±0.5% by a specific number.

[0146] 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.

[0147] In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to the above list, and can be changed or rearranged according to the required design. And the above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0148] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for calibrating a servo value of blood pressure measurement based on a volume compensation method, the method comprising: In a predetermined pressure collection period, a wearable sensor worn by a measured object is driven by a motor to sequentially apply a plurality of initial pressures to the measured object, and a plurality of blood pressure values ​​and photoplethysmography signals of the measured object are collected, wherein the plurality of initial pressures correspond to the plurality of blood pressure values ​​one by one; Calculating an initial average blood pressure of the subject based on the multiple blood pressure values; Based on the multiple initial pressures, determining from the photoplethysmographic signal a plurality of AC signal amplitudes corresponding to the multiple initial pressures; In the case where the magnitude relationship between the amplitudes of the multiple AC signals satisfies a first predetermined condition, generating pressure interval information based on the multiple initial pressures, wherein the multiple initial pressures at least include a first initial pressure, a second initial pressure, and a third initial pressure; Comparing the pressure interval information with the initial average blood pressure, and when the initial average blood pressure is greater than the maximum value of the pressure interval information, updating the first initial pressure, the second initial pressure, and the third initial pressure to a first target pressure, a second target pressure, and a third target pressure, respectively, wherein the first target pressure is determined based on the first initial pressure and a predetermined pulse pressure difference, the second target pressure is determined based on the first initial pressure, and the third target pressure is determined based on the second initial pressure; When the initial average blood pressure is less than the minimum value of the pressure interval information, the first initial pressure, the second initial pressure and the third initial pressure are respectively updated to a fourth target pressure, a fifth target pressure and a sixth target pressure, wherein the fourth target pressure is determined based on the second initial pressure, the fifth target pressure is determined based on the third initial pressure, and the sixth target pressure is determined based on the third initial pressure and the predetermined pulse pressure difference; Based on multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures, a target servo value is obtained, so that the motor is controlled by the target servo value to apply a pressure matching the blood vessel pressure of the measured object to the measured object.

2. The calibration method according to claim 1, wherein: The first initial pressure is less than the second initial pressure, the second initial pressure is less than the third initial pressure, the multiple AC signal amplitudes at least include a first AC signal amplitude corresponding to the first initial pressure, a second AC signal amplitude corresponding to the second initial pressure, and a third AC signal amplitude corresponding to the third initial pressure, and when the magnitude relationship between the multiple AC signal amplitudes satisfies a first predetermined condition, generating pressure interval information based on the multiple initial pressures includes: In the case where the amplitude of the second AC signal is greater than the amplitude of the third AC signal and the amplitude of the second AC signal is less than the amplitude of the first AC signal, the pressure interval information is generated using the first initial pressure as the interval lower limit and the second initial pressure as the interval upper limit; or The pressure interval information is generated by taking the minimum value of the initial average blood pressure as the lower limit of the interval and taking the first initial pressure as the upper limit of the interval.

3. The calibration method according to claim 2, wherein: When the magnitude relationship between the amplitudes of the multiple AC signals satisfies a first predetermined condition, generating the pressure interval information based on the multiple initial pressures further includes: In the case where the amplitude of the second AC signal is greater than the amplitude of the first AC signal and the amplitude of the second AC signal is less than the amplitude of the third AC signal, the pressure interval information is generated using the second initial pressure as the interval lower limit and the third initial pressure as the interval upper limit; or The pressure interval information is generated by taking the third initial pressure as the interval lower limit and taking the maximum value of the initial average blood pressure as the interval upper limit.

4. The calibration method according to claim 1, wherein: The obtaining of the target servo value based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures comprises: obtaining a target average blood pressure based on the multiple target pressures and multiple AC signal amplitudes corresponding to the multiple target pressures; The target servo value is obtained based on the target average blood pressure.

5. The calibration method according to claim 4, wherein: The obtaining of the target average blood pressure based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures comprises: Inputting the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures into a function to be fitted, and fitting to obtain fitting parameters of the function to be fitted; Based on the fitting parameters, the target mean blood pressure is determined.

6. The calibration method according to claim 5, wherein: The step of obtaining the target servo value based on the target average blood pressure comprises: acquiring a DC component of the target mean blood pressure from the photoplethysmography signal; Calculating an average value of the DC component of the target mean blood pressure; The average value is determined as the target servo value.

7. The calibration method according to claim 5, wherein: The step of obtaining the target servo value based on the target average blood pressure further comprises: determining an AC signal amplitude of the target mean blood pressure from the photoplethysmographic signal; The target servo value is obtained based on the AC signal amplitude of the target average blood pressure.

8. A calibration system for servo values ​​of blood pressure measurement based on volume compensation method, suitable for implementing the calibration method according to any one of claims 1 to 7, wherein: The calibration system comprises: An acquisition module, used to acquire multiple blood pressure values ​​and photoplethysmography signals of a subject within a predetermined pressure acquisition period; A calculation module, configured to calculate an initial average blood pressure of the subject based on the multiple blood pressure values; a determination module, configured to determine, based on the multiple initial pressures, from the photoplethysmographic signal, multiple AC signal amplitudes corresponding to the multiple initial pressures; a calibration module, configured to calibrate the multiple initial pressures based on the initial average blood pressure and a predetermined pulse pressure difference to obtain multiple target pressures corresponding to the multiple initial pressures when the magnitude relationship between the multiple AC signal amplitudes satisfies a first predetermined condition; The control module is used to obtain a target servo value based on the multiple target pressures and the multiple AC signal amplitudes corresponding to the multiple target pressures, so as to use the target servo value to apply a pressure matching the blood vessel pressure of the measured object to the measured object.

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