Gas circuit control system and control method thereof

Abstract

The invention relates to the technical field of medical instruments, and discloses an air path control system and a control method thereof.The air path control system is applied to a double-airbag sphygmomanometer and comprises a measuring air path, a sensing module, a first air path, a second air path, an air path switching module, an inflation and deflation module and a control module, and the sensing module is arranged on the measuring air path; the gas path switching module is connected with the measuring gas path, the first gas path and the second gas path, the gas path switching module has a first state and a second state, the measuring gas path is communicated with the first gas path in the first state, the measuring gas path is communicated with the second gas path in the second state, and the inflating and deflating module is communicated with the measuring gas path. Or is communicated with any two of the measuring gas path, the first gas path and the second gas path. The control module can achieve inflation and deflation control and blood pressure measurement of the outer air bag and the inner air bag only through pressure data obtained by the sensing module, the air path structure is simplified, the number of elements is reduced, and the overall size is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a pneumatic control system and its control method. Background Technology

[0002] Among existing non-invasive blood pressure measurement technologies, the oscillometric method is the most common. Traditional electronic blood pressure monitors typically use a single-cuff cuff. However, with technological advancements, the measurement accuracy of single-cuff electronic blood pressure monitors can no longer meet user needs. Therefore, dual-cuff electronic blood pressure monitors have emerged, which typically include an external cuff to block blood flow and an internal cuff to sense the pulse wave.

[0003] However, dual-bag electronic blood pressure monitors usually require a complex airway structure, which takes up a lot of space. This results in dual-bag blood pressure monitors being bulky and inconvenient to carry. Summary of the Invention

[0004] This invention provides an airway control system and its control method to solve the problems of existing dual-bag electronic blood pressure monitors having a large airway control system, which is usually quite complex and the airway structure of the airway control system occupies a large space, thus causing the dual-bag blood pressure monitor to be large in size and inconvenient to carry.

[0005] In a first aspect, the present invention provides an airway control system for use in a dual-bag sphygmomanometer, the dual-bag sphygmomanometer comprising an outer bag and an inner bag, the airway control system comprising:

[0006] Measuring the gas path; The sensing module is located in the measuring gas path and is suitable for detecting the gas pressure data in the measuring gas path. The first air passage is adapted to communicate with the outer airbag, and the second air passage is adapted to communicate with the inner airbag. The gas path switching module is connected to the measuring gas path, the first gas path, and the second gas path. The gas path switching module has a first state and a second state. In the first state, the measuring gas path is connected to the first gas path, and in the second state, the measuring gas path is connected to the second gas path. The control module is electrically connected to the sensing module and the gas path switching module, and is suitable for controlling the gas path switching module to switch between a first state and a second state based on gas pressure data. The inflation / deflation module is connected to the measuring gas path, or to any two of the measuring gas path, the first gas path, and the second gas path.

[0007] Beneficial effects: By adopting the above technical solution, the gas path control system only needs to install a sensing module in the measuring gas path. The control module can then control the gas path switching module to switch between a first state and a second state based on the air pressure data measured by the sensing module. This allows the measuring gas path to alternately connect with the first and second gas paths, thereby enabling the inflation and deflation of the outer and inner air bladders and completing the blood pressure measurement. This design simplifies the structure of the gas path control system, reduces the number of components, and effectively reduces the overall size, which is beneficial for the portability of the dual-bladder blood pressure monitor.

[0008] In one alternative implementation, the gas path control system further includes: The timing module, which is electrically connected to the control module, is suitable for recording the first time when the gas path switching module is in the first state and the second time when it is in the second state.

[0009] Secondly, the present invention also provides a control method for a gas path control system, the gas path control system including an inflation stage and an deflation stage, the control method including: During the inflation or deflation phase, the control sensor module acquires air pressure data in the measurement air path. The air path switching module is controlled based on air pressure data to switch between the first and second states.

[0010] Beneficial effects: When adopting the above technical solution, the control module can simultaneously or subsequently control the inflation / deflation module to perform inflation / deflation actions on the outer and inner airbags. It can also acquire the air pressure in the outer and inner airbags separately through a single sensor module located in the measurement air path. This ensures that the pressure data in the outer and inner airbags are collected by the same sensor module. Hardware-wise, this avoids the problem of inconsistencies in zero-point offset, linearity error, and temperature drift characteristics between the two sensor modules when independently collecting air pressure data from the outer and inner airbags. This inconsistency leads to system errors when calculating transwall pressure or difference signals, thus ensuring the accuracy of the air path control system's measurements.

[0011] In one optional implementation, the control method of the gas path control system includes the following steps: During the inflation phase, the control air path switching module switches between the first and second states to allow the inflation / deflation module to inflate the outer airbag and / or the inner airbag. When the air path switching module is in the first state, the control sensor module obtains the first air pressure of the external airbag; When the airway switching module is in the second state, the control sensor module obtains the second air pressure of the inner airbag; When the first air pressure reaches the first preset pressure and the second air pressure reaches the second preset pressure, the control module for inflation and deflation stops the air circuit control system from intake.

[0012] Beneficial effects: When the above technical solution is adopted, the control module can detect the air pressure of the outer airbag and inner airbag during the inflation process by a single sensor module while controlling the inflation module to perform the inflation action and controlling the air path switching module to switch between the first and second states. Moreover, this method of alternating measurement of air pressure data in the outer airbag and inner airbag by a single sensor module can effectively reduce the data processing load on the control module.

[0013] In one optional implementation, the step of controlling the gas path switching module to switch between a first state and a second state includes: The control gas path switching module first enters the first state; When the first air pressure reaches the first preset pressure, the control air path switching module enters the second state; Alternatively, the control gas path switching module can switch between the first and second states alternately in a preset manner.

[0014] In one optional implementation, the control method of the gas path control system further includes: During the deflation phase, the control air path switching module switches between the first and second states to allow the outer and inner airbags to deflate to the outside by the air path control system. When the airway switching module is in the second state, the control sensor module obtains the third air pressure of the inner airbag; The blood pressure of the subject is determined based on the third atmospheric pressure.

[0015] In one optional implementation, the control method of the gas path control system further includes: The control gas path switching module switches between the first and second states at a preset time period. When the air path switching module is in the first state, the control sensor module obtains the fourth air pressure of the external airbag; The time ratio within a preset time period when the fourth and third air pressure adjustment air path switching module is in the first state.

[0016] Beneficial effects: When the above technical solution is adopted, the control module, in the process of controlling the inflation and deflation module to perform the deflation action of the outer and inner airbags, can adjust the ratio of the time the airway switching module stays in the first state to the preset time period based on the fourth air pressure of the outer airbag and the third air pressure of the inner airbag. This adjusts the deflation speed of the outer and inner airbags, thereby adjusting the air pressure difference between the outer and inner airbags so that the transwall pressure between the outer and inner airbags meets the blood pressure measurement requirements of the airway control system, thus ensuring the accuracy of blood pressure measurement by the airway control system.

[0017] In one optional implementation, the step of adjusting the time ratio of the gas path switching module in the first state within a preset time period based on the fourth and third gas pressures includes: When the pressure difference between the fourth and third atmospheres exceeds a preset threshold, the time ratio is increased. When the pressure difference between the third and fourth air pressures exceeds a preset threshold, the time ratio is reduced.

[0018] In one optional implementation, the control method of the gas path control system further includes: After a preset time has elapsed since the gas path switching module switched to the second state, the control sensor module acquires the blood pressure of the person being tested.

[0019] Beneficial effects: When the above technical solution is adopted, after the control module controls the gas path switching module to switch from the first state to the second state for a preset time, it controls the sensing module to obtain the air pressure in the inner air bag to obtain the blood pressure of the subject. This can avoid the problem of errors in the air pressure data measured by the sensing module caused by the gas oscillation in the inner air bag during the initial stage of the intermittent deflation of the inner air bag when the gas path switching module switches between the first state and the second state, thus ensuring the accuracy of the blood pressure measurement by the gas path control system.

[0020] In one optional embodiment, the control method of the gas path control system further includes the following steps: When the airway switching module switches to the second state, it acquires the instantaneous air pressure of the inner airbag; The preset duration is adjusted based on instantaneous air pressure.

[0021] Beneficial effects: When the above technical solution is adopted, when the control module controls the airway switching module to switch to the second state, it can determine and adjust the preset duration based on the instantaneous air pressure when the inner airbag begins to deflate. In this way, the preset duration can be adjusted accordingly based on the instantaneous air pressure when the inner airbag begins to deflate each time. This ensures the accuracy of the air pressure data measured by the sensing module in the inner airbag, while also ensuring the duration of the air pressure data measurement by the sensing module, thereby further improving the accuracy of blood pressure measurement by the airway control system. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1This is a schematic diagram of the gas path control system according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a control method for a gas path control system according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating another control method for a pneumatic control system according to an embodiment of the present invention. Figure 4 This is a flowchart illustrating another control method for a pneumatic control system according to an embodiment of the present invention. Figure 5 This is a flowchart illustrating another control method for a pneumatic control system according to an embodiment of the present invention. Figure 6 This is a flowchart illustrating another control method for a pneumatic control system according to an embodiment of the present invention. Figure 7 This is a schematic flowchart of another control method for a pneumatic control system according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures: 100. Airway control system; 1. Sensing module; 2. Measuring airway; 3. Airway switching module; 4. Inflation / depression module; 5. First airway; 6. Second airway; 7. External airbag; 8. Internal airbag. Detailed Implementation

[0025] 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 embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “” used herein may also mean including the plural forms. The terms “comprising,” “including,” and “having” are inclusive and therefore indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0027] Although terms such as first, second, third, and fourth may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," "third," and "fourth," as well as other numerical terms, do not imply order or sequence when used in this document. Furthermore, in the description of this application, unless otherwise expressly specified and limited, the terms "set up" and "connected" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] For ease of description, spatial relative terms can be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "end," "inner," and "outer." Such spatial relative terms are intended to include different orientations of the mechanism in use or operation, in addition to the orientations depicted in the figure.

[0029] Existing dual-bag sphygmomanometers typically have two independent pressure sensing modules, each connected to the outer and inner bladders of the sphygmomanometer via air passages. This allows the sphygmomanometer to monitor the pressure in the inflated and deflated outer and inner bladders, thus measuring the patient's blood pressure. However, dual-bag sphygmomanometers with two independent pressure sensing modules usually require two separate air pumps and air passages, resulting in large size, high cost, and high power consumption. Furthermore, the inconsistencies in zero-point offset, linearity error, and temperature drift characteristics of the two sensing modules can lead to errors in data processing by the control module, ultimately causing errors in blood pressure measurement.

[0030] To solve the above problems, such as Figure 1As shown, this invention provides an airway control system 100 applied to a dual-bag sphygmomanometer. The dual-bag sphygmomanometer includes an outer bag 7 for blocking blood flow to the limbs and an inner bag 8 for detecting limb pulse fluctuations. The airway control system 100 includes a measuring airway 2, a sensing module 1, a first airway 5, a second airway 6, an airway switching module 3, and a control module (not shown). The sensing module 1 is located in the measuring airway 2 and is used to detect the air pressure data in the measuring airway 2. Specifically, the sensing module 1 is a pressure sensor, and more specifically, the sensing module 1 is a piezoresistive pressure sensor. The first airway 5 is connected to the outer bag 7, and the second airway 6 is connected to the inner bag 8. The air path switching module 3 is connected to the measuring air path 2, the first air path 5, and the second air path 6. The air path switching module 3 has a first state and a second state. In the first state, the measuring air path 2 is connected to the first air path 5 so that the sensing module 1 can measure the air pressure of the outer airbag 7. In the second state, the measuring air path 2 is connected to the second air path 6 so that the sensing module 1 can measure the air pressure of the inner airbag 8. The inflation / deflation module 4 is connected to the measuring air path 2 so that it can inflate the outer airbag 7 through the measuring air path 2 and the first air path 5, or inflate the inner airbag 8 through the measuring air path 2 and the second air path 6. The control module is electrically connected to the sensing module 1, the air path switching module 3, and the inflation / deflation module 4 so that the control module can alternately connect the measuring air path 2 to the first air path 5 and the measuring air path 2 to the second air path 6 when controlling the inflation / deflation module 4 to perform inflation / deflation actions. This allows the sensor module 1 to measure the air pressure data in the external airbag 7 or the internal airbag 8 while simultaneously inflating or deflating the external airbag 7 or the internal airbag 8.

[0031] In this invention, only one sensor module 1 needs to be set. With the above setting method, regardless of whether the inflation / deflation module 4 performs inflation or deflation, the control module can measure the air pressure data in the outer airbag 7 and the inner airbag 8 through a sensor module 1 set on the measuring air path 2 during the process of controlling the air path switching module 3 to switch between the first state and the second state.

[0032] Specifically, when the inflation / deflation module 4 inflates the outer airbag 7 and the inner airbag 8, the control module controls the air path switching module 3 to switch between a first state and a second state, thereby switching the connection state between the measuring air path 2 and the first air path 5, and between the measuring air path 2 and the second air path 6. This enables the inflation of the outer airbag 7 and the inner airbag 8, as well as the detection of their air pressure, thus completing the preparation work for blood pressure measurement by the dual-airbag sphygmomanometer. When the inflation / deflation module 4 deflates the outer airbag 7 and the inner airbag 8, the control module controls the air path switching module 3 to switch the connection state between the measuring air path 2 and the first air path 5, and between the measuring air path 2 and the second air path 6. This enables the measurement of the blood pressure of the subject while simultaneously detecting the pressure of the outer airbag 7 and the inner airbag 8. This simplifies the air path control system 100 of the present invention, reduces the number of components, effectively reduces the overall size, and facilitates the portability of the dual-airbag sphygmomanometer.

[0033] It should be noted that although the sensing module 1 described above is located inside the measuring air path 2, this is not a limitation. In specific implementations of the present invention, the sensing module 1 can also be located at the end of the measuring air path 2, but this is also not a limitation. Obviously, the sensing module 1 can also be located in other positions, as long as the sensing module 1 can detect the air pressure inside the measuring air path 2. For example, the sensing module 1 can also be connected to the measuring air path 2 through other air path connectors.

[0034] Furthermore, although the number of the above-described charging / discharging module 4 is one and it is connected to the measuring gas path 2, this is not limiting. Those skilled in the art can also set the number of charging / discharging modules 4 to two as needed, and configure the two charging / discharging modules 4 to be connected to any two of the measuring gas path 2, the first gas path 5, and the second gas path 6. Such adjustments do not depart from the basic principles of the present invention and therefore will also fall within the protection scope of the present invention.

[0035] Furthermore, the control module can be a control chip inherent in the dual-bag blood pressure monitor itself, a control unit specifically designed to execute the control method of the present invention, or a functional unit within the aforementioned control chip.

[0036] In this invention, the gas path control system 100 also includes a gas path main control board (not shown), on which the gas charging / discharging module 4, gas path switching module 3, sensing module 1, and control module are all integrated. Specifically, the control module uses a main control unit (MCU) as the core scheduling center, and through collaboration with a high-precision timer, an analog-to-digital converter (ADC module), and a DMA controller, it constructs an efficient and stable control and data processing link. The high-precision timer generates a precise control signal with a period of T, providing a reference for the timing synchronization of the entire system, and records absolute timestamps in real time, laying the foundation for timing traceability and logical linkage of gas path switching and data sampling. Based on this reference timing, the MCU outputs multi-channel control signals through general purpose input / output (GPIO): First, it outputs PWM or level signals to control the start and stop of the gas supply module in the gas charging / discharging module 4; second, it outputs linear voltage or PWM signals to adjust the opening of the exhaust module in the gas charging / discharging module 4, precisely controlling the depressurization speed; third, it outputs PWM signals or high-frequency switching signals to drive the gas path switching module 3 to quickly switch between the first and second states, working in conjunction with the ADC module at a high sampling rate (e.g., 1kHz) to ensure signal capture within the effective sampling window. To address the massive digital signal transmission requirements of the ADC module at its high sampling rate, the DMA controller electrically connected to the MCU is configured in "software discard mode," automatically transferring the ADC-converted digital signals to a dual buffer without consuming CPU resources, achieving high-speed batch data transmission and caching. The MCU, without needing to participate in the data transfer process, can focus on the timestamps and control signal timing based on a high-precision timer, coordinating the duty cycle adjustment of the PWM signal, the state logic judgment of gas path switching, and subsequent pressure calculation and estimation based on the effective data from the dual buffer. This forms a complete interactive closed loop: "high-precision timer timing reference → MCU instruction scheduling → multi-channel PWM / control signal output → ADC high-sampling-rate data acquisition → DMA high-speed transmission without CPU occupation." This ensures the real-time performance and accuracy of gas path switching and inflation / deflation control, while also improving system data processing efficiency through efficient data transfer via DMA, thereby achieving blood pressure measurement and ensuring measurement accuracy. Preferably, in a specific implementation of this invention, the gas path main control board also integrates a communication module. The communication module is used to convert the acquired pulse wave signal or the blood pressure data determined by the control module into an electrical signal and transmit it to an external device. The external device can be an electronic product such as a mobile phone, watch, or tablet computer that can convert the electrical signal sent by the communication module into blood pressure data and display it, so that the blood pressure monitor using the gas path control system of this invention can send the pulse wave signal or blood pressure data to the external device.

[0037] As one possible implementation, the gas path control system 100 also includes a timing module (not shown), which is electrically connected to the control module and is adapted to record the first time when the gas path switching module 3 is in the first state and the second time when it is in the second state.

[0038] This embodiment also provides a control method for a pneumatic control system, which is used to implement the above embodiments and preferred embodiments. Details that have been described will not be repeated here.

[0039] The following is combined Figures 2 to 7 This describes possible implementations of the control method for the pneumatic control system 100 of the present invention.

[0040] like Figure 2 As shown, in one possible embodiment, the control method of the pneumatic control system 100 of the present invention includes the following steps: S101: During the inflation or deflation phase, control sensor module 1 acquires air pressure data in air path 2. S102: Based on air pressure data, control the air path switching module 3 to switch between the first state and the second state.

[0041] Specifically, the control method of the airway control system 100 of the present invention includes an inflation stage and a deflation stage. Based on the airway structure of the airway control system 100, in any stage, the sensing module 1 continuously or intermittently acquires the air pressure data in the measuring airway 2. The control module then makes decisions and controls the working state of the airway switching module 3 based on this air pressure data, switching it between a first state and a second state. Here, the air pressure data is the sole direct basis for the control decision. The first state refers to the measuring airway 2 being connected to the first airway 5 connecting to the outer airbag 7 through the airway switching module 3. The second state refers to the measuring airway 2 being connected to the second airway 6 connecting to the inner airbag 8 through the airway switching module 3.

[0042] Through the aforementioned configuration, the gas path control system 100, via the collaborative operation of the single gas path switching module 3 and the single sensing module 1, manages and measures the pressure of the outer bladder 7 and the inner bladder 8 of the dual-bladder sphygmomanometer in a time-division multiplexing manner. This method aims to efficiently and collaboratively establish initial pressure for both bladders during the inflation phase. In the more critical deflation phase, the method dynamically adjusts the deflation rate of the two bladders to precisely maintain the transwall pressure between them, thereby creating stable and reliable conditions for blood pressure measurement based on the pressure oscillation wave of the inner bladder 8. The implementation of this method significantly simplifies the hardware structure and fundamentally eliminates the systematic errors that may arise from using two independent pressure sensors, ensuring the consistency of the measurement data source and ultimately improving the accuracy of blood pressure measurement and the portability of the device.

[0043] The inflation and deflation phases are described separately below.

[0044] like Figure 3As shown, in one possible implementation, during the inflation phase, the control method of the air circuit control system 100 of the present invention includes the following steps: S201: During the inflation phase, the control air path switching module 3 switches between the first state and the second state so that the inflation / deflation module 4 inflates the outer airbag 7 and / or the inner airbag 8. S202: When the air path switching module 3 is in the first state, the control sensor module 1 obtains the first air pressure of the external airbag 7; S203: When the air path switching module 3 is in the second state, the control sensor module 1 obtains the second air pressure of the inner airbag 8; S204: When the first air pressure reaches the first preset pressure and the second air pressure reaches the second preset pressure, control the inflation / deflation module 4 to stop the air circuit control system 100 from intake.

[0045] Specifically, during the inflation phase, the control module first activates the inflation pump in the inflation / deflation module 4. Simultaneously, the control module controls the air path switching module 3 to switch between a first state and a second state. When switched to the first state, airflow is directed to the outer airbag 7, and the pressure data detected by the sensing module 1 reflects the real-time pressure of the outer airbag 7, referred to as the first pressure. When switched to the second state, airflow is directed to the inner airbag 8, and the pressure detected by the sensing module 1 reflects the real-time pressure of the inner airbag 8, referred to as the second pressure. The control module continuously monitors these pressure data. When it determines that the first pressure has reached the first preset pressure set for the outer airbag 7, and the second pressure has reached the second preset pressure set for the inner airbag 8, the control module instructs the inflation / deflation module 4 to stop inflation, for example, by turning off the inflation pump, thus completing the inflation phase.

[0046] It should be noted that, in the control step S201, preferably, the air circuit control system 100 includes only one inflation / deflation module 4. Therefore, during the inflation phase, when the control module controls the air circuit switching module 3 to switch between the first and second states, the inflation / deflation module 4 can only alternately inflate the outer airbag 7 and the inner airbag 8, that is, the inflation / deflation module 4 inflates either the outer airbag 7 or the inner airbag 8. However, this is not limiting. In specific implementations of the invention, the number of inflation / deflation modules 4 can also be two. In this way, when the control module controls the air circuit switching module 3 to switch between the first and second states, it can inflate the outer airbag 7 and the inner airbag 8 respectively through the two inflation / deflation modules 4, that is, the inflation / deflation module 4 inflates both the outer airbag 7 and the inner airbag 8.

[0047] like Figure 4 As shown, in one possible embodiment, the control method of the pneumatic control system 100 of the present invention includes the following steps: S301: Control gas path switching module 3 first enters the first state; S302: When the first air pressure reaches the first preset pressure, the control air path switching module 3 enters the second state.

[0048] Specifically, during the inflation phase, a sequential inflation strategy can be adopted. The control module first controls the air path switching module 3 to enter the first state, at which point the inflation / deflation module 4 is dedicated to inflating the outer airbag 7. The sensing module 1 continuously monitors the first air pressure and feeds it back to the control module. When the control module determines that the first air pressure has reached the first preset pressure, it immediately issues a command to switch the air path switching module 3 to the second state, switching to inflating the inner airbag 8, until the second air pressure reaches the second preset pressure. This strategy has clear logic, simple control, and reduces the design difficulty of the control program during the inflation phase.

[0049] In a preferred embodiment of the present invention, an alternating switching strategy can also be employed. The control module controls the operation of the airway switching module 3 according to a preset switching mode. This preset mode can be a fixed time period, such as switching states every 100 milliseconds, so that the outer airbag 7 and the inner airbag 8 are alternately and intermittently inflated, allowing their pressures to rise more synchronously. The preset mode can also be an asymmetric duty cycle mode that varies with time. For example, in the initial stage of inflation, the airway switching module 3 stays in the first state for a longer time to quickly establish the baseline pressure of the outer airbag 7, and then the duty cycle is adjusted in the later stage to balance the final pressure of the two airbags. This method of alternating measurement of inflation pressure reduces the data processing load of the control module compared to processing data from two sensors simultaneously. It should be noted that the preset mode can also be based on determining the time ratio of the airway switching module 3 in the first and second states based on the first inflation volume of the outer airbag 7 and the second inflation volume of the inner airbag 8 at the end of the inflation phase of the dual-airbag sphygmomanometer, so as to alternately inflate the outer airbag 7 and the inner airbag 8.

[0050] like Figure 5 As shown, in one possible implementation, during the venting phase, the control method of the gas path control system 100 of the present invention includes the following steps: S401: During the deflation phase, the control air path switching module 3 switches between the first state and the second state so that the outer airbag 7 and the inner airbag 8 are deflated to the outside by the air path control system 100. S402: When the air path switching module 3 is in the second state, control the sensing module 1 to obtain the third air pressure of the inner airbag 8; S403: Determine the blood pressure of the subject based on the third atmospheric pressure.

[0051] Specifically, during the deflation phase, the control module controls the inflation / deflation module 4 to activate the deflation function, for example, by opening the exhaust valve. Similarly, the control module controls the air path switching module 3 to continue switching between the first and second states, allowing the gas in the outer airbag 7 and the inner airbag 8 to be alternately released to the outside through the measuring air path 2 and the exhaust valve. In particular, when the air path switching module 3 is in the second state, the third air pressure detected by the sensing module 1 directly reflects the pressure change of the inner airbag 8 during the deflation process. By analyzing the pressure oscillation wave characteristics caused by arterial pulsation contained in this third air pressure data, such as the maximum amplitude of the oscillation corresponding to the mean pressure, and combining this with the pressure drop curve, the control module can calculate the systolic and diastolic blood pressure of the subject.

[0052] When the above technical solution is adopted, the pressure detection of both the outer airbag 7 and the inner airbag 8 is completed by the same sensing module 1 in the measurement air path 2 throughout the entire deflation measurement process. This fundamentally eliminates the systematic errors introduced by the inherent differences in zero-point offset, linearity, and temperature drift characteristics between two independent sensors, which greatly ensures the accuracy of transwall pressure calculation or differential signal analysis.

[0053] like Figure 6 As shown, in one possible embodiment, the control method of the pneumatic control system 100 of the present invention includes the following steps: S501: Control gas path switching module 3 switches between the first state and the second state at a preset time period; S502: When the air path switching module 3 is in the first state, control the sensing module 1 to obtain the fourth air pressure of the external airbag 7; S503: When the air path switching module 3 is in the first state based on the fourth air pressure and the third air pressure, the time ratio within the preset time period.

[0054] Specifically, during the venting phase, the control module controls the gas path switching module 3 to cycle through a preset time period. Within this preset time period, i.e., within one cycle, the control module controls the gas path switching module 3 to complete one switch between the first and second states. For example, a time period of 500 milliseconds is set. Within each cycle, the gas path switching module 3 first enters the first state and lasts for a first time, which is less than the preset time period. After the duration of entering the first state reaches the first time, it switches to the second state. This cycle continues until the sum of the times in the first and second states reaches the preset time period, at which point the preset time period ends. This cycle repeats until the measurement is completed.

[0055] When the air path switching module 3 is in the first state, the sensing module 1 detects the fourth air pressure, i.e., the real-time pressure of the outer airbag 7. When it is in the second state, the sensing module 1 detects the third air pressure, i.e., the real-time pressure of the inner airbag 8. The control module compares the most recently acquired fourth air pressure with the third air pressure in each cycle or every few cycles.

[0056] Based on the comparison of these two air pressures, the control module dynamically adjusts the ratio of the time the air path switching module 3 remains in the first state to the total length of the preset time cycle in the next time period, i.e., the time ratio. The specific adjustment logic is as follows: the control module calculates the difference between the fourth and third air pressures. A preset difference threshold, such as 5 mmHg, is set within the system. If the difference between the fourth and third air pressures is greater than this threshold, it indicates that the pressure in the external airbag 7 is too high, and the transwall pressure may be too large. In this case, the control module increases the time ratio for the next cycle, i.e., extends the dwell time of the air path switching module 3 in the first state, thereby accelerating the deflation speed of the external airbag 7 and causing its pressure to drop faster, thus reducing the pressure difference between the two airbags. Conversely, if the difference between the third and fourth air pressures is greater than the difference threshold, it indicates that the pressure in the external airbag 7 is relatively low, and the transwall pressure is insufficient. In this case, the control module decreases the time ratio, shortening the deflation time of the external airbag 7, slowing its pressure drop, and thus increasing the pressure difference.

[0057] Through this closed-loop control based on real-time air pressure feedback, the system can automatically stabilize the pressure difference between the outer airbag 7 and the inner airbag 8 within an ideal range, creating a stable and optimal mechanical environment for the inner airbag 8 to detect weak arterial oscillation waves, thereby significantly improving the accuracy and reliability of blood pressure measurement.

[0058] In a preferred embodiment of the present invention, the control method of the gas path control system 100 further includes: after a preset time period when the gas path switching module 3 switches to the second state, controlling the sensing module 1 to acquire the blood pressure of the person to be tested.

[0059] Specifically, during the dynamic adjustment process of the deflation phase, whenever the gas path switching module 3 switches from the first state to the second state, due to the sudden change in the gas path connection and the effect of gas inertia, the gas in the inner airbag 8 and the connected measuring gas path 2 may experience brief turbulence or pressure fluctuations. If the data from the sensing module 1 is read immediately, the data may not stably and accurately reflect the static pressure of the inner airbag 8, thus leading to incorrect blood pressure readings.

[0060] To address this issue, the control module incorporates a stabilization waiting mechanism when performing blood pressure measurement sampling. Specifically, after each switch of the control gas path switching module 3 to the second state, it does not immediately read data from the sensor module 1 for blood pressure calculation. Instead, it waits for a preset duration, such as 50 milliseconds. After this preset duration, the gas flow in the gas path system has stabilized, and the pressure reading has returned to a stable level. Only then does the control module instruct the sensor module 1 to sample and obtain the stable third gas pressure for blood pressure analysis. This mechanism effectively avoids measurement errors introduced by transient interference during switching.

[0061] The specific control process is as follows: The main control unit generates a control signal with a period of T based on a high-precision timer. Within each period T, the control signal causes the gas path switching module 3 to maintain a first state for a first time, and then switch to a second state for a second time, where the sum of the first time and the second time equals the preset time period T. In both the first and second states, the control module divides the sampling timing of the sensing module 1 into two stages: a stabilization avoidance stage and an effective sampling window stage. In the stabilization avoidance stage, from the moment the gas path switching module 3 receives the switching command, a preset duration, such as 5ms-10ms, is maintained. During this period, the gas path is in a transient response process, and the fluid oscillates. The main control unit configures the ADC module to be in a stopped state, or configures the DMA controller to enable software discard mode to discard the conversion data within this time period, in order to prevent noise signals from interfering with the measurement results. Based on the principle that the higher the pressure, the longer the oscillation, the preset duration of the stabilization avoidance stage is adjustable. The main control unit can dynamically adjust the length of this preset duration according to the current pressure level, thereby maximizing the width of the effective sampling window to obtain more pulse wave feature points while ensuring data accuracy. Effective sampling window phase: This phase follows the stabilization and avoidance phase and continues until the connectivity state ends. Within this window, the gas pressure has reached a steady state. The main control unit activates the ADC module to continuously acquire analog signals at a high sampling rate and directly stores them into the effective data buffer via the DMA controller.

[0062] Furthermore, because the airway control system 100 employs an alternating sampling mode, the pressure signals of each path, especially the pulse wave signals contained in the internal air bladder 8, are discontinuous and discrete in time. Therefore, the control module acquires the discrete sampling points stored in the buffer within the effective sampling window of the sensing module 1, and reconstructs these discrete points into continuous pulse wave data through interpolation algorithms or signal fitting. The main control unit converts the extracted and reconstructed pulse wave signals into corresponding electrical signals, which are then transmitted to external devices via the communication module or used directly to calculate the blood pressure of the person being tested.

[0063] Furthermore, in the specific implementation of this invention, the DMA controller equipped with a software discard mode plays a crucial noise reduction role during the stabilization and avoidance phase. Specifically, during the pressure oscillation period generated at the moment of switching the airway connectivity state, in response to the timing control of the main control unit, the DMA controller activates the software discard mode, blocking the noise data converted by the ADC module during this phase from entering the effective data buffer, thereby avoiding interference with subsequent pulse wave feature extraction. Once the effective sampling window phase is entered, the DMA controller resumes normal operation, transferring the high-frequency digital signals continuously sampled by the ADC module to the buffer in real time. In this way, the control module uses interpolation algorithms or signal fitting to reconstruct these high-quality discrete segmented data into continuous pulse wave data. This not only physically isolates the oscillation noise at the source, ensuring the accuracy of blood pressure measurement, but also greatly reduces the computational load of the MCU by eliminating the need for frequent CPU intervention in the entire data transfer and discard process.

[0064] like Figure 7 As shown, in one possible implementation, the control method of the pneumatic control system 100 of the present invention includes the following steps: S601: When the air path switching module 3 switches to the second state, it acquires the instantaneous air pressure of the inner airbag 8; S602: Adjust the preset duration based on instantaneous air pressure.

[0065] Furthermore, to more intelligently determine the required stabilization time, this embodiment also dynamically adjusts the aforementioned preset duration. Specifically, the control module records the instantaneous value of the third air pressure at the moment the air path switching module 3 switches from the first state to the second state. This value represents the real-time pressure of the inner airbag 8 before the switch. The control module stores empirical data or calculation formulas corresponding to the optimal stabilization time for different pressure ranges. Based on this instantaneous air pressure value, the control module queries or calculates the most suitable stabilization waiting time and adjusts the preset duration of the delay measurement of the third air pressure by the sensing module 1 accordingly. For example, when the air pressure is high, the airflow speed may be faster, and the oscillation may be more obvious, requiring a longer stabilization time, so the preset duration can be set longer; conversely, when the air pressure is low, the waiting time can be appropriately shortened, so the preset duration can be set shorter. This adaptive adjustment ensures that stable and reliable sampling data can be obtained under various pressure conditions, further improving the measurement accuracy.

[0066] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A pneumatic control system applied to a dual-bag sphygmomanometer, the dual-bag sphygmomanometer comprising an outer bag and an inner bag, characterized in that, The gas path control system includes: Measuring the gas path; A sensing module, which is located in the measuring gas path, is adapted to detect the gas pressure data in the measuring gas path; A first air passage and a second air passage, wherein the first air passage is adapted to communicate with the outer airbag and the second air passage is adapted to communicate with the inner airbag; A gas path switching module is connected to the measuring gas path, the first gas path, and the second gas path. The gas path switching module has a first state and a second state. In the first state, the measuring gas path is connected to the first gas path, and in the second state, the measuring gas path is connected to the second gas path. A control module, which is electrically connected to the sensing module and the gas path switching module, is adapted to control the gas path switching module to switch between the first state and the second state based on the gas pressure data; The inflation / deflation module is connected to the measuring gas path, or to any two of the measuring gas path, the first gas path, and the second gas path.

2. The gas path control system according to claim 1, characterized in that, The gas path control system also includes: A timing module, which is electrically connected to the control module, is adapted to record the first time when the gas path switching module is in the first state and the second time when it is in the second state.

3. A control method for the gas path control system according to claim 1, characterized in that, The gas circuit control system includes an inflation stage and an deflation stage, and the control method includes: During the inflation or deflation phase, the sensing module is controlled to acquire the air pressure data in the measurement air path. Based on the air pressure data, the air path switching module is controlled to switch between the first state and the second state.

4. The control method of the gas circuit control system according to claim 3, characterized in that, The control method includes the following steps: During the inflation phase, the air path switching module is controlled to switch between the first state and the second state so that the inflation / deflation module inflates the outer airbag and / or the inner airbag. When the air path switching module is in the first state, the sensing module is controlled to obtain the first air pressure of the external airbag; When the air path switching module is in the second state, the sensing module is controlled to obtain the second air pressure of the inner airbag; When the first air pressure reaches the first preset pressure and the second air pressure reaches the second preset pressure, the inflation / deflation module is controlled to stop the air circuit control system from intake.

5. The control method for the gas path control system according to claim 4, characterized in that, The step of controlling the gas path switching module to switch between the first state and the second state includes: The gas path switching module is controlled to first enter the first state; When the first air pressure reaches the first preset pressure, the air path switching module is controlled to enter the second state; Alternatively, the gas path switching module can be controlled to alternate between the first state and the second state in a preset manner.

6. The control method for the gas path control system according to claim 3, characterized in that, The control method further includes: During the deflation phase, the air path switching module is controlled to switch between the first state and the second state so that the outer airbag and the inner airbag are deflated to the outside by the air path control system. When the air path switching module is in the second state, the sensing module is controlled to acquire the third air pressure of the inner airbag; The blood pressure of the person being tested is determined based on the third air pressure.

7. The control method for the gas path control system according to claim 6, characterized in that, The control method further includes: The gas path switching module is controlled to switch between the first state and the second state at a preset time period; When the air path switching module is in the first state, the sensing module is controlled to acquire the fourth air pressure of the external airbag; The time proportion within the preset time period is adjusted based on the fourth and third air pressures when the gas path switching module is in the first state.

8. The control method for the gas path control system according to claim 7, characterized in that, The step of adjusting the time ratio of the gas path switching module in the first state within the preset time period based on the fourth gas pressure and the third gas pressure includes: When the pressure difference between the fourth air pressure and the third air pressure is greater than a preset difference threshold, the time ratio is increased. When the pressure difference between the third and fourth air pressures exceeds a preset threshold, the time ratio is reduced.

9. The control method for the gas circuit control system according to any one of claims 6-8, characterized in that, The control method further includes the following steps: After a preset time has elapsed since the gas path switching module switched to the second state, the sensing module is controlled to acquire the blood pressure of the person to be tested.

10. The control method for the gas path control system according to claim 9, characterized in that, The control method further includes the following steps: When the air path switching module switches to the second state, it acquires the instantaneous air pressure of the inner airbag; The preset duration is adjusted based on the instantaneous air pressure.

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