Method and device for controlling air valve of SMA sphygmomanometer to release air at fixed air release speed, electronic equipment and storage medium

Abstract

The invention relates to a method for controlling an air valve of an SMA sphygmomanometer to deflate at a fixed deflation speed. The method comprises the steps that an air pressure value is collected, and the change speed of an air pump is calculated to adjust the air pump to inflate to a set value; the air leakage speed of the air pump is calculated, and the first output duty ratio is adjusted, so that the SMA sphygmomanometer leaks air at the fixed air leakage speed; and according to the first output duty ratio, the air leakage speed and the fixed air leakage speed, a second output duty ratio is calculated, and the air pump air leakage process is adjusted through duty ratio amplitude limiting till air leakage is completed. By means of the method and device for controlling the air valve of the SMA sphygmomanometer to conduct deflation at the fixed deflation speed, the electronic equipment and the storage medium, the following problems caused by the too high deflation speed can be solved: early pulsation amplitude sampling is insufficient, and first effective pulsation missing possibly occurs; coupling change of bandwidth and noise is introduced due to instability of the air leakage speed, and the stability of pulsation envelope fitting is influenced; the measurement time is prolonged due to too slow air leakage, discomfort of a tested person is easily caused, and the motion artifact probability is increased.

Description

Technical Field

[0001] This invention relates to the field of medical measurement and control technology, specifically to a method, apparatus, electronic device, and storage medium for controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate. Background Technology

[0002] Cuff blood pressure monitors typically use an air pump to inflate the blood vessels and then collect the pulsating signal generated as the pressure decreases during deflation. Systolic and diastolic blood pressure are estimated based on the oscillation method or related algorithms.

[0003] Traditional deflation methods often rely on mechanical needle valves, orifice plate throttling, or pulse width modulation control of solenoid valves. Due to factors such as nonlinearity of the gas path, high sensitivity of valve opening to flow rate, cuff volume changes, micro-movements of the subject's limbs, residual pressure of the air pump, and fluctuations in power supply voltage, the actual deflation rate often varies at any time. Excessive deflation rate can lead to insufficient sampling of early pulsation amplitude, potentially causing the first effective pulsation to be "missed". Unstable deflation rate introduces coupling changes in bandwidth and noise, affecting the stability of pulsation envelope fitting. Excessive deflation prolongs the measurement time, which can easily cause discomfort to the subject and increase the probability of motion artifacts.

[0004] SMA blood pressure monitors use SMA (Silk Magnesium Ammonium Hydrocarbon) wire to control the valve. Compared to traditional blood pressure monitors, SMA valves are lighter, consume less power, are noiseless, and have no electromagnetic interference. The valve control in SMA blood pressure monitors is completely different from traditional valves. The SMA wire's temperature changes with the amount of current flowing through it, causing a phase transition. When using an SMA blood pressure monitor, it's necessary to balance the lifespan of the SMA wire with the deflation rate. Excessive temperature can cause overheating, significantly impacting the wire's lifespan. Therefore, the SMA wire temperature must be controlled within its phase transition temperature range to ensure optimal lifespan. Furthermore, the valve opening size in an SMA blood pressure monitor is also temperature-dependent. Compared to solenoid valve-type blood pressure monitors, after setting the valve opening size to a fixed deflation rate, it's also necessary to additionally control the SMA wire temperature within the temperature range corresponding to the set opening size. Therefore, SMA blood pressure monitors are greatly affected by temperature, and temperature control can be used to balance the deflation rate and lifespan of the SMA blood pressure monitor.

[0005] Therefore, existing technologies have shortcomings and need to be improved and developed. Summary of the Invention

[0006] The present invention provides a method, apparatus, electronic device, and storage medium for controlling the deflation valve of an SMA blood pressure monitor at a fixed deflation rate. This addresses the problems in the prior art where traditional deflation methods rely on mechanical needle valves, orifice plate throttling, or pulse width modulation control of solenoid valves. These methods often suffer from variations in actual deflation rate due to factors such as nonlinearity of the air path, high sensitivity of valve opening to flow rate, cuff volume changes, micro-movements of the subject's limbs, residual pressure in the air pump, and fluctuations in power supply voltage. This can lead to problems such as excessively fast deflation rates resulting in insufficient sampling of early pulse amplitude, potentially causing the first effective pulse to be "missed"; unstable deflation rates introducing bandwidth and noise coupling changes, affecting the stability of pulse envelope fitting; and excessively slow deflation prolonging measurement time, easily causing discomfort to the subject and increasing the probability of motion artifacts.

[0007] In a first aspect, the present invention provides a method for controlling the gas valve of an SMA blood pressure monitor to release gas at a fixed rate, comprising:

[0008] Real-time acquisition of air pressure values ​​from the SMA blood pressure monitor detected by the air pressure sensor;

[0009] Adjust the air pump to inflate to the set value based on the air pressure value and the calculated air pump change rate.

[0010] The deflation rate of the air pump is calculated based on the air pressure value, and the first output duty cycle is adjusted based on the deflation rate so that the SMA blood pressure monitor deflates at the required fixed deflation rate.

[0011] The second output duty cycle is calculated based on the first output duty cycle, the venting speed, and the fixed venting speed, so as to adjust the air pump venting process by limiting the duty cycle until venting is completed.

[0012] Furthermore, adjusting the air pump to inflate to the set value based on the air pump change rate calculated from the air pressure value includes:

[0013] The SMA filament in the SMA blood pressure monitor is energized at 80% duty cycle for 200ms, and then continuously energized at 20% duty cycle.

[0014] The air pressure value of the air pressure sensor is read every 1ms. The change rate of the air pump is obtained by subtracting the air pressure value of the next 1ms time from the air pressure value of the current 1ms time interval and dividing the result by the 1ms time interval.

[0015] Compare the pump's rate of change with the pump's standard rate of pressure increase. If the pump's rate of change is greater than or equal to the pump's standard rate of pressure increase, then turn off the pump, stop inflation, and replace with a new SMA blood pressure monitor to inflate to the set value while ensuring that the pump's rate of change is less than the pump's standard rate of pressure increase. If the pump's rate of change is less than the pump's standard rate of pressure increase, then continue inflation to the set value.

[0016] Furthermore, the set value is 140, and the unit is mmHg.

[0017] Furthermore, the step of calculating the deflation rate of the air pump based on the air pressure value, and adjusting the first output duty cycle based on the deflation rate to allow the SMA blood pressure monitor to deflate at the desired fixed deflation rate, includes:

[0018] Adjust the initial duty cycle to a range of 15% to 20%, and adjust the duration of each power-on cycle to a range of 500ms to 1s;

[0019] The first output duty cycle value, which is the same as the initial duty cycle value, is output to the drive circuit where the SMA filament is located, so as to control the SMA filament to be energized with the first output duty cycle.

[0020] Determine whether the deflation rate is within 5% of the fixed deflation rate. If the deflation rate is within 95% to 105% of the fixed deflation rate, continue deflation and enter the PID closed-loop control stage. Otherwise, adjust the first output duty cycle by 1% step size until the deflation rate is within 95% to 105% of the fixed deflation rate and enter the PID closed-loop control stage. That is, if the deflation rate is less than 95% of the fixed deflation rate, the deflation rate is too low, so increase the first output duty cycle by 1% of the value of the first output duty cycle until the deflation rate is within 95% to 105% of the fixed deflation rate. If the deflation rate is greater than 105% of the fixed deflation rate, the deflation rate is too high, so decrease the first output duty cycle by 1% of the value of the first output duty cycle until the deflation rate is within 95% to 105% of the fixed deflation rate.

[0021] Furthermore, the step of calculating the second output duty cycle based on the first output duty cycle, the venting speed, and the fixed venting speed, and adjusting the air pump venting process by limiting the duty cycle until venting is completed, includes:

[0022] An incremental PID controller is used to calculate the deviation by taking the difference between the fixed venting speed and the real-time venting speed as input, and outputting the increment of the SMA wire duty cycle. ;

[0023] Calculate the increment of the first output duty cycle and the SMA filament duty cycle. The sum of the values ​​is used to obtain the second output duty cycle;

[0024] The second output duty cycle is controlled to be energized within the set upper and lower limits of the duty cycle to adjust the air pump venting process until venting is completed.

[0025] Furthermore, the incremental PID controller uses the difference between the fixed venting speed and the real-time venting speed as input to calculate the deviation, and outputs the increment of the SMA filament duty cycle. ,include:

[0026] The increment of the duty cycle of the output SMA filament The calculation formula is:

[0027] ;

[0028] in, This is the proportionality constant, with a value of 2.5;

[0029] This is the integral coefficient, with a value of 0.1;

[0030] is the differential coefficient, with a value of 0.05;

[0031] , , Represent The difference between the time-based deflation rate and the real-time deflation rate, The difference between the previous deflation rate and the real-time deflation rate. The difference between the first two deflation rates and the real-time deflation rate, with an interval of 1ms between each adjacent deflation rate.

[0032] Furthermore, controlling the second output duty cycle to be energized within a set upper and lower limit range to adjust the air pump venting process until venting is completed includes:

[0033] The duty cycle of the second output is adjusted within the range of 5% to 40%, wherein the upper limit of the duty cycle limit is 40% and the lower limit is 5%.

[0034] A second aspect of the present invention provides a device for controlling the gas valve of an SMA blood pressure monitor to release gas at a fixed rate, characterized in that it comprises:

[0035] The data acquisition module is used to acquire the air pressure value of the SMA blood pressure monitor detected by the air pressure sensor in real time;

[0036] The first calculation module is used to adjust the air pump to inflate to a set value based on the air pump change rate calculated from the air pressure value.

[0037] The second calculation module is used to calculate the air pump's deflation rate based on the air pressure value, and adjust the first output duty cycle based on the deflation rate so that the SMA blood pressure monitor deflates at the required fixed deflation rate.

[0038] The adjustment module is used to calculate the second output duty cycle based on the first output duty cycle, the venting speed, and the fixed venting speed, so as to adjust the air pump venting process by limiting the duty cycle until venting is completed.

[0039] In a third aspect, the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the electronic device implements the method of controlling the air valve of an SMA blood pressure monitor to release air at a fixed deflation rate.

[0040] In a fourth aspect, the present invention provides a computer-readable storage medium for storing a computer program that, when executed on a computer, causes the computer to perform the method of controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate.

[0041] Beneficial effects:

[0042] As can be seen from the above technical solutions, the present invention provides a method for controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate, which has the following beneficial effects:

[0043] 1. Constant deflation rate: Two-stage control, consisting of coarse adjustment and closed-loop PID, is adopted to keep the actual deflation rate within ±5% of the fixed deflation rate, which helps to stabilize the pulsation envelope sampling conditions and improve the consistency of blood pressure estimation.

[0044] 2. Achieved no missed detection of early beats: By controlling the upper limit to suppress excessively rapid deflation, the risk of the first beat being skipped is reduced, and the accuracy of systolic blood pressure estimation is improved.

[0045] 3. Reduce steady-state error: Estimate the leakage rate with a sampling period of 1ms and correct it in real time. Fine-tune the duty cycle in 1% increments to enter the error band before closing the loop, taking into account both response speed and steady-state error.

[0046] 4. Improved safety of the blood pressure monitor: By limiting the duty cycle of the second output to 5%~40%, the risk of SMA overheating and the inability of the blood pressure monitor valve to close is reduced, thereby improving device lifespan and measurement safety.

[0047] 5. Consistent control: By comparing the rate of change of the air pump with the standard pressurization rate, the system status is checked to avoid deviations in the initial conditions caused by excessively rapid inflation, thereby improving the effectiveness of subsequent deflation control.

[0048] 6. High compatibility: The method relies only on pressure sensor readings, SMA drive circuit and microcontroller software strategy, without the need to modify the main gas path components, is compatible with existing hardware, and is easy to use directly on the SMA valve blood pressure monitor platform.

[0049] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0050] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0051] The accompanying drawings are not drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0052] Figure 1 This is a flowchart illustrating a method for controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate, according to an embodiment of this application.

[0053] Figure 2 This is a flowchart of step S104 of a method for controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate, according to an embodiment of this application.

[0054] Figure 3 This is a flowchart of step S106 of a method for controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate, according to an embodiment of this application.

[0055] Figure 4 This is a flowchart of step S108 of a method for controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate, according to an embodiment of this application.

[0056] Figure 5 This is a control venting logic diagram for a method of controlling the air valve of an SMA blood pressure monitor to vent at a fixed venting rate, according to an embodiment of this application.

[0057] Figure 6This is a general framework diagram of a method for controlling the air valve of an SMA blood pressure monitor to release air at a fixed rate, according to an embodiment of this application.

[0058] Figure 7 This is a schematic diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0060] The terms "first," "second," and similar words used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the features, integrals, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or sets thereof. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0061] A shape memory alloy (SMA) blood pressure monitor is an electronic blood pressure monitor that uses shape memory alloy wire as a valve actuator in its gas circuit. Electrical heating drives the SMA wire to undergo a phase change, which, through levers, springs, or guide rod mechanisms, actuates the valve core or throttling component to change the equivalent opening of the venting channel, thereby controlling the inflation and deflation process. Its basic components typically include: an air pump, an SMA-driven air valve, a pressure sensor, a microcontroller, and an SMA drive circuit. The SMA wire acts as a resistive load, generating different heating powers controlled by the PWM duty cycle; through heat dissipation and elastic reset, the valve position returns to its initial state after cooling.

[0062] In existing technologies, traditional deflation methods mostly rely on mechanical needle valves, orifice plate throttling, or pulse width modulation control of solenoid valves. Due to factors such as nonlinearity of the gas path, high sensitivity of valve opening to flow rate, cuff volume changes, micro-movements of the subject's limbs, residual pressure of the air pump, and fluctuations in power supply voltage, the actual deflation rate often varies at any time. This can easily lead to insufficient sampling of early pulsation amplitude due to excessively fast deflation, potentially causing the first effective pulsation to be "missed". Unstable deflation rate introduces coupling changes in bandwidth and noise, affecting the stability of pulsation envelope fitting. Excessively slow deflation prolongs the measurement time, easily causing discomfort to the subject and increasing the probability of motion artifacts.

[0063] In view of this, embodiments of the present invention provide a method for controlling the gas valve of an SMA blood pressure monitor to release gas at a fixed rate, referring to... Figure 1 ,include:

[0064] Step S102: Real-time acquisition of air pressure values ​​from the SMA blood pressure monitor detected by the air pressure sensor.

[0065] Step S104: Adjust the air pump to inflate to the set value based on the air pump change rate calculated from the air pressure value.

[0066] Step S106: Calculate the deflation rate of the air pump based on the air pressure value, and adjust the first output duty cycle based on the deflation rate so that the SMA blood pressure monitor deflates at the required fixed deflation rate.

[0067] Step S108: Calculate the second output duty cycle based on the first output duty cycle, the venting speed, and the fixed venting speed, and adjust the air pump venting process by limiting the duty cycle until venting is completed.

[0068] After pressure acquisition, inflation speed verification and inflation to the set value, estimation of deflation speed and coarse adjustment using the first output duty cycle, and calculation combining the fixed deflation speed and real-time deflation speed, the final calculation is performed. After steps including superimposing the second output duty cycle and limiting the amplitude, maintaining the closed loop until deflation is complete, the air valve of the SMA sphygmomanometer is controlled to deflate at a fixed rate. During the process, the air pressure value is read in with a 1ms sampling period, the deflation rate is calculated differentially, and the SMA wire is driven by PWM to adjust the valve opening. This achieves a near-constant fixed deflation rate by adjusting the valve opening over time within repeatable sampling and control cycles.

[0069] In some embodiments, reference is made to Figure 2 The air pump is adjusted to inflate to the set value based on the calculated air pressure change rate, including:

[0070] Step S1041: Control the SMA filament in the SMA blood pressure monitor to be energized at 80% duty cycle for 200ms, and then continuously energized at 20% duty cycle.

[0071] Step S1042: Read the air pressure value of the air pressure sensor every 1ms. Divide the value obtained by subtracting the air pressure value of the adjacent 1ms time interval from the current 1ms air pressure value and divide it by the 1ms interval to obtain the air pump change rate.

[0072] Step S1043: Compare the pump change rate with the pump standard pressure increase rate. If the pump change rate is greater than or equal to the pump standard pressure increase rate, turn off the pump, stop inflation, and replace with a new SMA blood pressure monitor to inflate to the set value while ensuring that the pump change rate is less than the pump standard pressure increase rate. If the pump change rate is less than the pump standard pressure increase rate, continue inflation to the set value.

[0073] First, a higher duty cycle is used to initiate the movement of the SMA filament and bring it to a steady state. Then, the pump's rate of change is calculated at 1ms intervals and compared with the standard pressurization rate. If the condition is met, inflation continues to the set value; otherwise, it stops and the device is replaced. An 80% duty cycle is applied for 200ms to quickly drive the mechanism to reset or close the valve, then maintained at 20%. The pump's rate of change is calculated and compared with the calibrated standard pressurization rate to determine whether to allow continued inflation, thereby eliminating abnormal inflation states and ensuring the consistency of the deflation start point (i.e., the set value) and safety during deflation.

[0074] In some embodiments, the set value is 140, in mmHg. The set value is adjustable based on actual measurements, and generally 140 mmHg is sufficient for blood pressure measurement. When the set value is 140 mmHg as the deflation initiation pressure reference, inflation is considered complete when the set value is greater than or equal to 140 mmHg, and the deflation phase begins. This standardization of the initiation pressure improves the consistency between deflation rate control and pulsation detection.

[0075] In some embodiments, reference is made to Figure 3 The process involves calculating the deflation rate of the air pump based on the air pressure value, and adjusting the first output duty cycle based on the deflation rate to deflate the SMA blood pressure monitor at the desired fixed deflation rate, including:

[0076] Step S1061: Adjust the initial duty cycle to a range of 15% to 20%, and adjust the duration of each power-on cycle to a range of 500ms to 1s.

[0077] Due to the high temperature sensitivity of SMA filament, the temperature drops significantly during initial venting as the airflow passes through it. Therefore, venting is initially performed with a small duty cycle before the PID closed-loop control phase. The initial duty cycle setting range is based on the thermal characteristics of the SMA filament model and is determined through factory calibration to ensure that the initial valve opening corresponds to 70%~80% of the required fixed venting speed. The energizing duration setting range is based on temperature sensor feedback to ensure that the SMA filament temperature fluctuation does not exceed 2℃ within the duration interval.

[0078] Step S1062: Output the value of the first output duty cycle, which is the same as the initial duty cycle value, to the drive circuit where the SMA filament is located, so as to control the SMA filament to be energized with the first output duty cycle.

[0079] Step S1063: Determine whether the deflation speed is within 5% of the fixed deflation speed. If the deflation speed is within 95% to 105% of the fixed deflation speed, continue deflation and enter the PID closed-loop control stage; otherwise, adjust the first output duty cycle by 1% step size until the deflation speed is within 95% to 105% of the fixed deflation speed and enter the PID closed-loop control stage. That is, if the deflation speed is less than 95% of the fixed deflation speed, the deflation speed is too low, so the first output duty cycle is increased by 1% of the value of the first output duty cycle until the deflation speed is within 95% to 105% of the fixed deflation speed; if the deflation speed is greater than 105% of the fixed deflation speed, the deflation speed is too high, so the first output duty cycle is decreased by 1% of the value of the first output duty cycle until the deflation speed is within 95% to 105% of the fixed deflation speed.

[0080] Open-loop regulation is performed using the initial duty cycle and energizing duration. The system checks if the system has entered a fixed venting speed error band of ±5%. If not, the first output duty cycle is adjusted in 1% increments until it enters the error band, at which point the system switches to the closed-loop stage. These steps reduce overshoot caused by large deviations in the initial closed-loop operation, improving efficiency and stability in reaching steady state.

[0081] In some embodiments, reference is made to Figure 4 The second output duty cycle is calculated based on the first output duty cycle, the venting speed, and the fixed venting speed. The venting process of the air pump is adjusted by limiting the duty cycle until venting is complete, including:

[0082] Step S1081: An incremental PID controller is used to calculate the deviation by taking the difference between the fixed venting speed and the real-time venting speed as input, and outputting the increment of the SMA filament duty cycle. An incremental PID controller is used to avoid the risk of sudden output changes associated with an absolute PID controller.

[0083] Step S1082: Calculate the increment of the first output duty cycle and the SMA filament duty cycle. The sum of the values ​​is used to obtain the second output duty cycle.

[0084] Step S1083: Control the second output duty cycle to be energized within the set upper and lower limits of the duty cycle to adjust the air pump venting process until venting is completed.

[0085] Using the difference between the fixed venting rate and the real-time venting rate as input, the incremental PID controller outputs the duty cycle increment. The second output duty cycle is obtained by adding it to the first output duty cycle. Upper and lower limits are applied to the second output duty cycle, and SMA is driven. This achieves approximately constant venting speed within a small error range and suppresses excessive duty cycle adjustment.

[0086] In some embodiments, an incremental PID controller is used to calculate the deviation by taking the difference between the fixed venting rate and the real-time venting rate as input, and outputting the increment of the SMA filament duty cycle. ,include:

[0087] Increment of duty cycle of output SMA filament The calculation formula is:

[0088] ;

[0089] in, This is the proportionality constant, with a value of 2.5;

[0090] This is the integral coefficient, with a value of 0.1;

[0091] is the differential coefficient, with a value of 0.05;

[0092] , , Represent The difference between the time-based deflation rate and the real-time deflation rate, The difference between the previous deflation rate and the real-time deflation rate. The difference between the first two deflation rates and the real-time deflation rate, with an interval of 1ms between each adjacent deflation rate.

[0093] In some embodiments, controlling the second output duty cycle to be energized within a set upper and lower limit range of the duty cycle to adjust the air pump venting process until venting is completed includes:

[0094] The duty cycle of the second output is controlled to be adjusted within the range of 5% to 40%, with the upper limit of the duty cycle limit being 40% and the lower limit being 5%.

[0095] By setting duty cycle limits, with an upper limit of 40% and a lower limit of 5%, it is convenient to control the SMA heat load and valve stroke boundary, thereby improving reliability and safety. On the other hand, under prolonged energization, the temperature of the SMA filament can exceed 120 degrees Celsius, leading to fatigue failure. Continuous energization with too small a duty cycle will cause the SMA filament to over-cool, lose its contractile force, and thus fail to control the valve port. Therefore, upper and lower limits are set for the duty cycle, with an upper limit of 40% and a lower limit of 5%. This ensures the stability and controllability of the SMA filament by continuously energizing with a duty cycle greater than 40% and continuously energizing with a duty cycle less than 5%.

[0096] Reference Figure 5 It shows the logic diagram for controlling venting, combined with Figure 6 The provided general framework diagram shows that the airbag, air pressure sensor, air pump, and deflation valve of the SMA blood pressure monitor are all on the same air path and are uniformly controlled by the control board, realizing the method provided in this application for controlling the air valve of the SMA blood pressure monitor to deflate at a fixed deflation rate.

[0097] Another embodiment of the present invention provides a device for controlling the gas valve of an SMA blood pressure monitor to release gas at a fixed rate, characterized in that it comprises:

[0098] The data acquisition module is used to acquire the air pressure value of the SMA blood pressure monitor detected by the air pressure sensor in real time;

[0099] The first calculation module is used to adjust the air pump to inflate to the set value based on the air pump change rate calculated from the air pressure value.

[0100] The second calculation module is used to calculate the air pump's deflation rate based on the air pressure value, so as to adjust the first output duty cycle based on the deflation rate so that the SMA blood pressure monitor deflates at the required fixed deflation rate.

[0101] The adjustment module is used to calculate the second output duty cycle based on the first output duty cycle, the venting speed, and the fixed venting speed, so as to adjust the air pump venting process by limiting the duty cycle until venting is completed.

[0102] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0103] Based on the same inventive concept as the above method embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it enables the electronic device to implement the control method described in the above embodiments.

[0104] In one embodiment, the electronic device may be a server, and in this embodiment, the structure of the electronic device may be as follows: Figure 7 As shown, it includes a memory, a communication module, and one or more processors.

[0105] Memory is used to store computer programs executed by the processor. Memory can be mainly divided into a program storage area and a data storage area. The program storage area can store the operating system and programs required to run instant messaging functions, etc.; the data storage area can store various instant messaging information and operation instruction sets, etc.

[0106] Memory can be volatile memory, such as random access memory (RAM); memory can also be non-volatile memory, such as read-only memory, flash memory, hard disk drive (HDD), or solid-state drive (SSD); or memory can be any other medium capable of carrying or storing a desired computer program having the form of instructions or data structures and accessible by a computer, but is not limited thereto. Memory can be a combination of the above-mentioned types of memory.

[0107] A processor may include one or more central processing units (CPUs) or digital processing units, etc. The processor is used to implement the aforementioned audio data processing methods when it invokes computer programs stored in memory.

[0108] The communication module is used to communicate with terminal devices and other servers.

[0109] This application embodiment does not limit the specific connection medium between the above-described memory, communication module, and processor. This application embodiment... Figure 7 The memory and processor are connected via a bus, and the bus is in... Figure 7 The connections between other components are illustrated with arrows and are for illustrative purposes only, not as limiting information. Buses can be categorized as address buses, data buses, control buses, etc. For ease of description, Figure 7 The text uses only one arrow to describe it, but does not indicate that there is only one bus or one type of bus.

[0110] Based on the same inventive concept as the above-described method embodiments, embodiments of the present invention also provide a computer-readable storage medium for storing a computer program. When the computer program is run on a computer, it enables an electronic device to implement the control methods described in the above embodiments. The computer-readable storage medium can be a readable signal medium or a readable storage medium. A readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0111] Based on the same inventive concept as the above-described method embodiments, embodiments of the present invention also provide a computer program product. The computer program product includes a computer program that, when run on an electronic device, causes the electronic device to perform the steps of the control methods described above according to various exemplary embodiments of this application. The program product may take the form of any combination of one or more readable media. These computer program commands can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the commands executed by the processor of the computer or other programmable data processing device generate a process for implementing... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0112] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A method of controlling a gas valve of an SMA sphygmomanometer to deflate at a fixed rate, characterized by, The method comprises: real-time acquisition of the air pressure value of the SMA sphygmomanometer detected by the air pressure sensor; adjustment of the air pump inflation to the set value according to the air pressure value; calculation of the air pump deflation speed according to the air pressure value, so as to adjust the first output duty cycle based on the deflation speed to deflate the SMA sphygmomanometer at the required fixed deflation speed; calculation of the second output duty cycle according to the first output duty cycle, the deflation speed and the fixed deflation speed, so as to adjust the air pump deflation process in the form of duty cycle limiting until the deflation is completed.

2. A method of controlling the air valve of an SMA sphygmomanometer to deflate at a fixed rate according to claim 1, characterized in that, The adjustment of the air pump inflation to the set value according to the air pressure value comprises: controlling the SMA wire in the SMA sphygmomanometer to be powered on for 200 ms at a duty cycle of 80%, and continuously powered on at a duty cycle of 20%; reading the air pressure value of the air pressure sensor every 1 ms, and obtaining the air pump change speed by dividing the difference between the air pressure value of the current 1 ms and the air pressure value of the adjacent 1 ms by the interval time of 1 ms; comparing the air pump change speed with the standard air pump pressure increasing speed, and if the air pump change speed is greater than or equal to the standard air pump pressure increasing speed, then closing the air pump, ending the inflation and replacing the new SMA sphygmomanometer to inflate to the set value under the condition that the air pump change speed is less than the standard air pump pressure increasing speed; if the air pump change speed is less than the standard air pump pressure increasing speed, then continuously inflating to the set value.

3. A method of controlling the air valve of an SMA sphygmomanometer to deflate at a fixed rate according to claim 2, characterized in that, The set value is 140 mmHg.

4. A method of controlling the air valve of an SMA sphygmomanometer to deflate at a fixed rate according to claim 1, wherein, The calculation of the air pump deflation speed according to the air pressure value, so as to adjust the first output duty cycle based on the deflation speed to deflate the SMA sphygmomanometer at the required fixed deflation speed, comprises: adjusting the initial duty cycle to be within the range of 15% to 20%, and adjusting the duration of each power-on to be within the range of 500 ms to 1 s; outputting the value of the first output duty cycle to the driving circuit where the SMA wire is located, so as to control the SMA wire to be powered on at the first output duty cycle; judging whether the deflation speed is within the error range of 5% of the fixed deflation speed, if the deflation speed is within the range of 95% to 105% of the fixed deflation speed, then continuing to deflate and entering the PID closed-loop control stage; otherwise, adjusting the first output duty cycle by a step of 1% to meet the condition that the deflation speed is within the range of 95% to 105% of the fixed deflation speed and enter the PID closed-loop control stage, that is, if the deflation speed is less than 95% of the fixed deflation speed, the deflation speed is low, then increasing the first output duty cycle by 1% of the value of the first output duty cycle until the deflation speed is within the range of 95% to 105% of the fixed deflation speed; if the deflation speed is greater than 105% of the fixed deflation speed, the deflation speed is high, then decreasing the first output duty cycle by 1% of the value of the first output duty cycle until the deflation speed is within the range of 95% to 105% of the fixed deflation speed.

5. A method of controlling the air valve of an SMA sphygmomanometer to deflate at a fixed rate according to claim 1, wherein, The second output duty cycle is calculated according to the first output duty cycle, the deflation speed, and the fixed deflation speed to regulate the air pump deflation process by duty cycle limiting until the deflation is completed. An incremental PID controller is used to take the difference between the fixed air release speed and the real-time air release speed as the input for deviation calculation, and output the increment of the SMA wire duty cycle ; computing a sum of values of the first output duty cycle, the increment of the SMA wire duty cycle to obtain the second output duty cycle; The second output duty cycle is controlled to be powered on within the upper and lower limit range of the set duty cycle to regulate the air pump deflation process until the deflation is completed.

6. A method of controlling the air valve of an SMA sphygmomanometer to deflate at a fixed rate according to claim 5, wherein, The incremental PID controller takes the difference between the fixed air release speed and the real-time air release speed as input to perform deviation calculation, and outputs the duty ratio increment of the SMA wire , comprising: The output SMA wire duty cycle increment The calculation formula is: ; wherein, is a proportionality factor having a value of 2.5; is the integral coefficient, and has a value of 0.1; Differential coefficient, value 0.05; , , Represent The difference between the time-based deflation rate and the real-time deflation rate, The difference between the previous deflation rate and the real-time deflation rate. The difference between the first two deflation rates and the real-time deflation rate, with an interval of 1ms between each adjacent deflation rate.

7. A method of controlling the air valve of an SMA sphygmomanometer to deflate at a fixed rate according to claim 5, wherein, The second output duty cycle is controlled to be powered on within the upper and lower limit range of the set duty cycle to regulate the air pump deflation process until the deflation is completed. The second output duty cycle is controlled to be powered on within the range of 5% to 40% to perform duty cycle regulation, wherein the upper limit of the duty cycle limiting is 40% and the lower limit is 5%.

8. A device for controlling the air valve of an SMA sphygmomanometer to deflate at a fixed rate, characterized in that, It comprises: The acquisition module is used to acquire the air pressure value of the SMA sphygmomanometer detected by the air pressure sensor in real time. The first calculation module is used to calculate the air pump change speed to adjust the air pump inflation to the set value according to the air pressure value. The second calculation module is used to calculate the deflation speed of the air pump according to the air pressure value to adjust the first output duty cycle based on the deflation speed to deflate the SMA sphygmomanometer at the required fixed deflation speed. The adjustment module is used to calculate the second output duty cycle according to the first output duty cycle, the deflation speed, and the fixed deflation speed to regulate the air pump deflation process by duty cycle limiting until the deflation is completed.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to enable the electronic device to implement the method for controlling the air valve of the SMA sphygmomanometer to deflate at the fixed deflation speed according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium is used to store the computer program, and when the computer program runs on the computer, the computer is enabled to execute the method for controlling the air valve of the SMA sphygmomanometer to deflate at the fixed deflation speed according to any one of claims 1-7.

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