Multi-parameter monitoring and multi-mode control oxygen therapy remote monitoring system and control method

Abstract

According to the multi-parameter monitoring and multi-mode control oxygen therapy remote monitoring system and the control method, in the whole oxygen therapy process, a central processing unit executes an output medium closed-loop control loop while executing a blood oxygen-flow feedback control loop or executing a blood oxygen-oxygen concentration feedback control loop. Flow is controlled through a blood oxygen feedback closed loop, and the blood oxygen of a patient is maintained at the optimal level. Meanwhile, the flow, humidity, temperature, pressure or oxygen concentration of the output oxygen is dynamically sensed, regulated and controlled, so that the flow, humidity, temperature, pressure or oxygen concentration of the output oxygen is stably maintained in a target interval, and an intelligent oxygen therapy ecological system is established.

Description

Technical Field

[0001] This invention relates to healthcare informatics, specifically to the field of ICT for treatment or health improvement. Background Technology

[0002] Oxygen therapy is the most common means of correcting abnormal oxygenation caused by various reasons and maintaining vital functions. During oxygen therapy monitoring, oxygen flow rate and blood oxygen saturation (SpO2) are among the parameters most closely monitored by healthcare professionals. Based on the variable relationship between oxygen input flow rate and SpO2, the applicant has proposed several technical solutions, including CN104826204A and CN108310566A, which dynamically adjust oxygen flow rate according to a set target SpO2, ensuring the patient's SpO2 is stably controlled within the target range. After these technical solutions were converted into medical device products for clinical application, research revealed that many medical data monitoring aspects are still lacking in the field of oxygen therapy monitoring, indicating significant deficiencies. For example, maintaining the output oxygen at humidity and temperature similar to natural inhalation is a new technical requirement for reducing clinical risks and improving patient compliance and comfort. However, in existing oxygen therapy processes, although humidification bottles (also known as humidification cups) are used to humidify the output oxygen, there is no dynamic monitoring of the output oxygen humidity or temperature, making it impossible to verify whether the output oxygen humidity or temperature is suitable for the patient. For example, during oxygen therapy, blockages caused by twisting, bending, or knotting of the oxygen tubing during patient turning over or sleeping are a common clinical risk. Current technology lacks dynamic monitoring data on the patency of the oxygen tubing. If blockages are not promptly identified, alerted, and intervened, they can lead to patient hypoxia or even suffocation. Furthermore, they can cause pressure overload within the humidification fluid container, potentially leading to container rupture and posing a safety risk.

[0003] Timeliness, accuracy, and remote management of medical data are key technologies for early identification and intervention of clinical risks, and are also one of the core components of improving the level of medical informatization in my country. To address the shortcomings of existing oxygen therapy monitoring technologies, this application proposes a multi-parameter monitoring and multi-modal control remote oxygen therapy monitoring system and control method to meet the higher-level clinical informatization needs of modern medicine. Summary of the Invention

[0004] This application proposes a remote monitoring system and control method for oxygen therapy with multi-parameter monitoring and multi-modal control.

[0005] A remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control includes a flow control unit, a blood oxygen monitoring module, an adjustable humidification module, an output medium sensing module, a memory, a communication module, a central processing unit, and a human-machine interface.

[0006] The flow control unit includes a flow valve and a flow sensor, and is controlled by a central processing unit. Wherein: Flow valves are used to regulate the output flow rate of oxygen. These valves may include miniature electronic gas flow control valves or proportional valves. Based on instructions from the central processing unit, the flow valve dynamically adjusts the oxygen output, including executing commands such as opening the valve, adjusting the flow rate, or closing the valve.

[0007] The flow sensor is used to dynamically monitor and measure the oxygen flow rate output from the oxygen output path and feed it back to the central processing unit.

[0008] The upstream gas passage of the flow control unit is connected to the output pipeline of the oxygen supply source, and the downstream gas passage of the flow control unit is connected to the adjustable humidification module or oxygen inhalation pipeline (including nasal oxygen tube or mask).

[0009] The aforementioned blood oxygen monitoring module is used to non-invasively and in real-time monitor the patient's blood oxygen saturation (SpO2) data and feed it back to the central processing unit. The blood oxygen monitoring module mainly consists of a blood oxygen sensor and a blood oxygen calculation module. The blood oxygen sensor is coupled to the monitored site on the patient (such as the finger or the sole of a newborn's foot) to dynamically monitor the patient's SpO2, and can also simultaneously monitor the pulse rate and perfusion index (PI).

[0010] The adjustable humidification module is a device used to humidify or heat the oxygen supplied to the patient. The adjustable humidification module is controlled by a central processing unit, and its humidification amount or heating power is adjustable and controllable. The adjustable humidification module includes a humidification container, a humidification liquid, an output control element, and connecting circuitry. Wherein: A humidification container is used for pre-filling and sealing humidification fluid. Humidification containers are made of medical-grade polymer materials, and their shape and structure are not limited. The outer periphery of the humidification container has an oxygen inlet and an oxygen outlet. The oxygen inlet is the channel through which oxygen enters the humidification container, while the oxygen outlet connects to oxygen delivery lines such as oxygen tubing or a face mask, and is the channel through which humidified oxygen is delivered to the patient.

[0011] Humidifying fluid is a medical liquid used to humidify oxygen and increase its humidity. It is usually made of pharmaceutical-grade purified water or sterile water. During oxygen therapy, humidifying fluid can be temporarily added to the humidifying fluid container. Typically, the humidifying fluid is pre-filled and sealed inside the container.

[0012] In one embodiment, the humidifying liquid container is further provided with an oxygen guide tube, which is used to guide the input oxygen to the bottom of the humidifying liquid, disperse the oxygen into small bubbles, and improve the humidification effect.

[0013] The output control element is an electronic component that uses humidifying liquid to humidify or heat oxygen and increase the humidity or temperature of the output oxygen. The output control element is controlled by the central processing unit and is located on the inner wall at the bottom of the humidification container or at the tail of the oxygen guide tube.

[0014] In one embodiment, based on the physical principle that liquid temperature is positively correlated with liquid evaporation rate, the output control element employs a heating element. By heating the humidifying liquid, the liquid evaporation rate is accelerated, thereby increasing the humidity and temperature of the output oxygen. The heating element comprises an insulated heating wire coil and a PI heating film.

[0015] In one embodiment, based on the physical principle that high-frequency ultrasonic oscillation of liquid accelerates liquid atomization and evaporation, in order to improve the humidification rate, the output control element is further provided with an ultrasonic atomizing plate for humidification. The ultrasonic atomizing plate is disposed on the inner wall of the humidification container or at the tail of the oxygen guide tube and the oxygen dispersion device. It is preferable that the ultrasonic atomizing plate is immersed in the humidification liquid.

[0016] The advantages of ultrasonic humidification are its fast response speed and significant increase in humidity. However, using ultrasonic nebulizers alone for humidification has significant drawbacks, such as: (1) over-humidification is easy, and water droplets can easily accumulate inside the oxygen delivery line, causing patients to choke on water; (2) the temperature of the output oxygen after humidification is not increased, and the comfort of the oxygen entering the respiratory tract is not as good as the heating and humidification output method using heating element technology. Therefore, in another embodiment, the output control element uses a combination of heating element and ultrasonic nebulizer. The heating element increases the oxygen output temperature, and the ultrasonic nebulizer increases the humidification rate. The advantage of using a combination of heating element and ultrasonic nebulizer is that the oxygen heating or humidification can be controlled separately according to the set target value, making the adjustment method simpler and the control more precise.

[0017] The output medium sensing module is used to monitor the physical parameters of the output medium in real time and feed them back to the central processing unit. The output medium includes oxygen and moisture, primarily oxygen. The output medium sensing module is integrated into the adjustable humidification module or the oxygen output path, and includes one or more of the following: humidity sensor, temperature sensor, pressure sensor, or oxygen concentration sensor. The humidity sensor is used to dynamically monitor the oxygen humidity at the output after the oxygen is humidified by the humidifying liquid, and then feeds it back to the central processing unit.

[0018] The temperature sensor is used to dynamically monitor the oxygen temperature when it is heated and output, and then feeds it back to the central processing unit.

[0019] Pressure sensors are used to dynamically monitor the pressure inside the adjustable humidification module or oxygen output path and feed it back to the central processing unit.

[0020] The oxygen concentration sensor is used to dynamically monitor the oxygen concentration (FiO2) delivered to the patient after oxygen humidification.

[0021] The output medium sensing module includes a humidity sensor, a temperature sensor, a pressure sensor, and an oxygen concentration sensor. They can be independently set in the adjustable humidification module or the oxygen output path respectively, or integrated into a multi-parameter output multi-functional sensing module. For example, the humidity sensor, temperature sensor, and pressure sensor are set in the path between the adjustable humidification module and the end of the oxygen output path, and the oxygen concentration sensor is set outside the mask or nose tip at the end of the oxygen output path. Preferably, the output medium sensing module adopts a sensing module with integrated multi-parameter output and is set in the adjustable humidification module or the oxygen output path.

[0022] Based on the current hospital infection control requirements, products that are not easily cleaned and disinfected are required to be used once. The adjustable humidification module is a disposable component supporting the oxygen therapy monitoring device described in this application, and the adjustable humidification module uses the oxygen input port and the oxygen output interface of the oxygen therapy monitoring device for quick combination.

[0023] The described memory is used to store control programs, monitoring information, and device operation information.

[0024] The communication module is used for remotely sending dynamic monitoring data, device operation information, and prompt alarm information, and dynamically uploading the obtained monitoring data to the medical terminal. The medical terminal includes but is not limited to HIS system, CIS system, LIS system, and nursing software system. The communication module includes but is not limited to technical methods such as wired transmission, Bluetooth, WiFi, or RF, etc. Preferably, a WiFi communication module is adopted.

[0025] The human-machine interaction interface is mainly used for power on / off, parameter setting, function setting, and information reading.

[0026] The central processing unit is an integrated circuit mainly constructed based on a core processor, a signal processor, etc. The core processor includes a microcontroller (MCU) or a CPU, etc.; a control program software is provided in the central processing unit, and the control program software is burned in the memory; the central processing unit is used to exchange information with logical components, perform data analysis and processing, issue execution instructions, and issue prompt and alarm information, etc.

[0027] The central processing unit is electrically connected to the blood oxygen monitoring module, the output medium sensing module, the adjustable humidification module, and the flow control unit. It is configured by the central processing unit to form a feedback control loop that includes blood oxygen, flow rate, humidity, temperature, pressure, or oxygen concentration. It dynamically senses and regulates the flow rate, humidity, temperature, pressure, or oxygen concentration of the output oxygen to keep the flow rate, humidity, temperature, pressure, or oxygen concentration of the output oxygen stably within the target range.

[0028] In one embodiment, a carbon dioxide monitoring module is also provided, which is electrically connected to the central processing unit. The sampling port of the carbon dioxide monitoring module is located on the periphery of the patient's exhalation port, dynamically collecting the carbon dioxide concentration in the patient's exhaled airflow, and feeding back the acquired end-tidal CO2 concentration, partial pressure (ETCO2), and carbon dioxide curve to the central processing unit.

[0029] A carbon dioxide curve is a graph plotting the measured carbon dioxide concentration against corresponding time points during respiration. The standard curve consists of four parts: the ascending limb, the alveolar plateau, the descending limb, and the baseline. Expiration begins at point P on the ascending limb, proceeds through point Q to point R, with QR representing the alveolar plateau (also known as the peak phase). Point R represents the peak value of the alveolar plateau, indicating the carbon dioxide concentration at the end of expiration (also known as the end-tidal phase). The descending limb marks the beginning of inspiration, and as fresh air is inhaled, the carbon dioxide concentration gradually returns to the baseline. Therefore, clinically, PQR is defined as the expiratory phase, and RSP as the inspiratory phase.

[0030] A control method, configured by the central processing unit, to perform the following operations: 1. The executed blood oxygen-flow feedback control loop includes: the central processing unit receiving real-time SpO2 data sent by the blood oxygen monitoring module; comparing the real-time SpO2 with a preset target SpO2 range; if the real-time SpO2 is lower than the target range, generating a first control command to increase the flow rate and sending it to the flow control unit; if the real-time SpO2 is higher than the target range, generating a second control command to decrease the flow rate and sending it to the flow control unit; if the real-time SpO2 is stably maintained within the target range, generating a command to maintain the current flow rate.

[0031] Alternatively, it could be an oxygen-to-oxygen concentration feedback control loop. This loop includes: an oxygen concentration adjustment range of 21%-100%; the central processing unit receiving real-time SpO2 data from the oxygen monitoring module; comparing the real-time SpO2 with a preset target SpO2 range; if the real-time SpO2 is below the target range, generating a third control command to increase the oxygen concentration and sending it to the flow control unit; if the real-time SpO2 is above the target range, generating a fourth control command to decrease the increased oxygen concentration and sending it to the flow control unit; and if the real-time SpO2 remains stably within the target range, maintaining the current increased oxygen concentration.

[0032] 2. The humidity, temperature, and pressure of the output oxygen will change accordingly when the flow rate increases or decreases. For example, when the oxygen flow rate increases, the humidity and temperature of the output oxygen decrease, while the output pressure increases. Therefore, the central processing unit executes an output medium closed-loop control loop simultaneously with the blood oxygen-flow feedback control loop or the blood oxygen-oxygen concentration feedback control loop. The execution of the output medium closed-loop control loop includes: The central processing unit receives real-time temperature, humidity, and pressure data sent by the output medium sensing module. The central processing unit compares the acquired monitoring data with the respective preset target values; Based on the comparison results of humidity or temperature data, the central processing unit generates a fifth control command to adjust the adjustable humidification module, regulating the humidification rate or heating power of the output control element to ensure that the output oxygen humidity or temperature reaches and is maintained within a preset target range. Specifically, the settable humidity control range in the central processing unit control program includes at least 40%RH-100%RH, and the settable temperature control range includes at least 20℃-41℃. Preferably, the settable humidity control range is 70%RH-100%RH, and the settable temperature control range is 32℃-38℃. In the central processing unit control program, the default humidity control range is 95%RH±2%, and the default temperature control range is 37℃±1℃.

[0033] Based on the comparison of flow and pressure data, diagnostic data for oxygen delivery status is generated. When the output flow rate decreases and the pressure in the oxygen delivery pipeline increases, an abnormal oxygen delivery status is diagnosed. Abnormal delivery status includes blocked pipes or other causes leading to poor ventilation. The human-machine interface provides prompts or warnings and generates a sixth control command for the flow control unit to intervene and adjust the output oxygen flow rate. This sixth control command includes reducing the oxygen output flow rate or closing the oxygen output valve.

[0034] When the central control unit fails to issue a second control command to reduce the flow rate, but the output flow rate decreases arbitrarily while the pressure in the oxygen delivery pipeline remains normal, an abnormal oxygen supply status is diagnosed. This abnormality includes insufficient oxygen supply volume or pressure, prompting the flow control unit to issue a seventh control command to increase the oxygen output flow rate. If, after executing the seventh control command (e.g., 3 minutes), the abnormal oxygen supply status is not resolved, the human-machine interface will display a prompt or warning, requiring manual intervention. Once manual intervention is completed, or the output flow rate and pressure return to normal, the prompt or alarm will automatically clear.

[0035] In embodiments equipped with a carbon dioxide monitoring module, the central processing unit automatically adjusts the oxygen output based on the end-tidal CO2 concentration or partial pressure (ETCO2) to maintain ETCO2 at a near-normal level. Simultaneously, it pulses the oxygen output according to the carbon dioxide curve, delivering oxygen normally during the inspiratory phase (RSP) and pausing oxygen delivery during the expiratory phase (PQR) to conserve oxygen consumption.

[0036] Compared with existing technologies, the technical advantages of this application are as follows: Throughout the entire oxygen therapy process, while executing the blood oxygen-flow feedback control loop, it monitors multiple parameters of the output oxygen, including flow rate, temperature, humidity, pressure, and oxygen concentration. This forms a closed-loop feedback control system for multimodal regulation of flow rate, humidity, temperature, pressure, and oxygen concentration through a "sensing-decision-execution" mechanism, establishing an intelligent oxygen therapy ecosystem integrating monitoring, treatment, management, and safety assurance. This application has the following beneficial effects: 1. Achieved precision in oxygen therapy technology: Through closed-loop control of blood oxygen feedback, the oxygen flow rate or oxygen concentration is dynamically adjusted to always maintain the patient's blood oxygen at the optimal level, thereby improving efficacy and safety.

[0037] 2. Significantly improves the comfort of oxygen therapy: Based on the PID control algorithm of flow-temperature-humidity established within the control program, the working power of the output control element is dynamically adjusted, ensuring that the output oxygen reaches the target temperature or humidity smoothly and quickly, avoiding temperature or humidity oscillations, and achieving stable closed-loop control of the output oxygen temperature and humidity. It outputs warm and humid oxygen that is essentially consistent with the body's natural environment, avoiding respiratory dryness or coldness, overcoming the long-standing shortcomings of existing humidification technologies, and improving patient compliance with oxygen therapy.

[0038] 3. Enhanced safety of the oxygen therapy system: Real-time monitoring of multiple parameters constitutes a complete safety monitoring network, which can provide early warning of poor pipeline ventilation, pressure overload in the humidification liquid container, and timely warning of potential risks such as insufficient oxygen supply at the oxygen source (including central oxygen supply stations or oxygen cylinders), greatly improving clinical safety. Attached Figure Description

[0039] Figure 1 This is a block diagram illustrating the working principle of this application. Figure 2 This is a schematic diagram of the external structure of this application. Figure 3 This is a schematic diagram of the execution logic framework of the central processing unit of this application. The diagram shows: oxygen therapy monitoring equipment main unit 10, flow control unit 20, blood oxygen monitoring module 30, output medium sensing module 40, human-machine interface 50, adjustable humidification module 60, humidification container 601, humidification liquid 602, output control element 603, connecting circuit 604, oxygen guide tube 605, and oxygen inhalation tube 606. Detailed Implementation

[0040] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] Example 1: Preparation of a main unit for an oxygen therapy monitoring device 10 The main structure of the product is as follows: Figure 2 The specific parameters of the main components shown are as follows: 1. The flow control unit 20 includes a flow valve composed of a micro stepper motor, a valve needle, a reduction gear, and a valve body. The flow rate is adjusted by regulating the throttling area between the valve needle and the air inlet through the stepper motor. The micro stepper motor operates at 3.5V, is two-phase four-wire, has 42 steps, and a step angle of 15 degrees. The flow rate adjustment range of the flow control unit 20 is 0-15L.

[0042] 2. Requirements for the flow sensor included in the flow control unit 20: measuring range not less than 0-10L / min, permissible error ±0.2L / FS, and power supply voltage 3.3V.

[0043] 3. The blood oxygen monitoring module 30 adopts a finger clip blood oxygen probe and a blood oxygen monitoring motherboard (Guangdong Sicheng). The blood oxygen monitoring range is 65%-100%, with an accuracy of 1%; the allowable error is ±2% (no definition below 75%).

[0044] 4. Output medium sensing module 40, using an AHT20+BMP280 temperature, humidity, and pressure / concentration three-in-one module, powered by 3.3V. (The details are as follows:) Temperature monitoring resolution is 0.1℃, with an allowable error of ±0.3℃, and a measurement range of not less than 0-50℃; Humidity monitoring resolution is 0.1%RH, with an allowable error of ±2%RH, and a measurement range of not less than 0-50%RH; The pressure monitoring resolution is 0.01 kPa, the allowable error is 0.1 kPa, and the measurement range is not less than 0-500 kPa.

[0045] 5. The human-computer interaction interface 50 consists of a conventional LCD screen and touch buttons.

[0046] 6. The adjustable humidification module 60 is constructed using a humidification container 601, a humidification liquid 602, an output control element 603, a connection circuit 604, and an oxygen guide tube 605, wherein: The humidification container 601 is made of medical-grade PET material and manufactured by blow molding. The bottle wall thickness is 0.3mm, the pressure resistance is not less than 0.4MPa, and the internal volume is 300ml.

[0047] (2) The top of the humidification container 601 lid is provided with an oxygen inlet and the right side is provided with an oxygen outlet. The oxygen inlet is required to match the gas supply interface of the oxygen therapy monitoring device host 10 and the oxygen outlet is required to match the gas inlet connector of the oxygen inhalation tube 606.

[0048] (3) At the center of the inner circumference of the humidification container 601, there is a circular mounting hole that is combined with the oxygen guide tube 605. The inner diameter of the circular mounting hole is 10mm.

[0049] (4) The humidification container 601 is also provided with a hole for the installation of the output medium sensing module 40, specifically located on the left side of the oxygen output port.

[0050] (5) The oxygen guide tube 605 is produced by extrusion process, with an outer diameter of 9.8 mm and a wall thickness of 0.3 mm. The outer circumference of the oxygen guide tube 605 is a perfect circle, and the inside is a double-channel double-lumen pipeline. The main cavity is the oxygen guide cavity, and the secondary cavity is the wiring cavity for connecting the circuit 604.

[0051] 7. Central Control Unit: An integrated circuit using an STM32F103RCT6 32-bit microcontroller (MCU) as the main control chip. The memory uses a W25Q128JVSIQ SOIC-8 surface-mount memory chip. The communication module uses an ESP32-C3FH4 QFN-32 WiFi + Bluetooth dual-mode wireless communication chip. The control motherboard is manufactured using traditional integrated circuit surface-mount technology. Figure 3 The central processing unit shown executes logic, programs control programs, and burns the control programs into memory.

[0052] 8. According to Figure 2 The external structure diagram shown illustrates the design and manufacture of a protective shell to encapsulate components such as the central control unit, flow control unit 20, blood oxygen monitoring module 30, communication module, and human-machine interface 50.

[0053] Example 2: One method for constructing a "blood oxygen-oxygen concentration feedback control loop" within the central control unit. like Figure 2As shown, the central control unit uses a set target SpO2 as the target point, and the blood oxygen monitoring module 30 dynamically monitors the patient's SpO2. The central control unit analyzes and calculates the fitting state between the patient's SpO2 and the target SpO2. Control adjustments are executed according to the following control logic: 1. If the patient's real-time SpO2 is below the target range, a third control command to increase the oxygen concentration is generated and sent to the flow control unit 20; 2. If the real-time SpO2 is higher than the target range, a fourth control command to reduce the oxygen concentration is generated and sent to the flow control unit 20; if the real-time SpO2 is within the target range, a command to maintain the current oxygen concentration is generated.

[0054] 3. When the patient's SpO2 deviates from the target SpO2, the flow control unit 20 dynamically corrects the oxygen concentration of the output oxygen to keep the patient's SpO2 stably within the target SpO2 range.

[0055] Specifically, for example: the target SpO2 for this patient's oxygen therapy is set at 94%-98%, and the prescribed oxygen concentration is 33%. During oxygen therapy, if the patient's SpO2 ≤ 94%, the flow control unit 20 uses titration to adjust the oxygen concentration, increasing the output oxygen concentration with a titration adjustment coefficient of 2% (i.e., increasing or decreasing the oxygen concentration by 2% each time). Conversely, if the patient's SpO2 ≥ 98%, the flow control unit 20 uses titration to adjust the output oxygen concentration with a titration adjustment coefficient of 2%, ensuring that the patient's SpO2 remains stably within the target SpO2 range of 94%-98%. If the patient's SpO2 remains within the target SpO2 range of 94%-98%, the current state is maintained.

[0056] Example 3: One method for constructing the "output medium closed-loop control loop" within the central control unit. The output medium sensing module 40 dynamically monitors the humidity or temperature of the output oxygen. The central processing unit performs comparative analysis between the acquired humidity or temperature and the set target value, and controls the humidity or temperature of the output oxygen in a closed loop. Specific methods include: S1 sensing and adjustable humidification module 40 dynamically monitor the humidity or temperature of the output oxygen at the oxygen output end. The oxygen output end includes, but is not limited to, the interior of the humidifier, oxygen delivery tubing, nasal cannula, and mask.

[0057] In S2 decision-making, the central processing unit analyzes and compares the humidity or temperature values ​​it reads with the set target humidity or temperature values. For example, it uses an established flow-temperature-humidity PID control algorithm to develop an adaptive temperature and humidity target curve and quickly calculate the heating power or humidification rate.

[0058] S3 execution: If the humidity or temperature of the output oxygen is too low, calculate and increase the working power of the output control element 603 or the ultrasonic atomizing plate to increase the humidity or temperature of the output oxygen. If the humidity or temperature of the output oxygen is too high, calculate and reduce the working power of the output control element 603 or the ultrasonic atomizing plate to reduce the humidity or temperature of the output oxygen. If the humidity or temperature of the output oxygen remains stable within the set range, the existing operating state of the output control element 603 or the ultrasonic atomizing plate is maintained.

[0059] For example, by controlling electronic switches such as MOSFETs through pulse width modulation (PWM) signals, the power of the supply output control element 603 is precisely adjusted according to the S2 decision program, so that the humidity or temperature of the output oxygen is kept stable within the set range, providing patients with a comfortable gas that is warm and humid.

[0060] Example 4: In the "output medium closed-loop control loop" of the central control unit, one type of PID control algorithm is based on flow rate, temperature, and humidity. To accelerate the closed-loop control of the output medium's humidity or temperature, a PID control program based on flow rate-temperature-humidity is established using the relationship between output humidity H, heater power U (control variable), and oxygen flow rate F (disturbance variable). This system employs a cascaded PID control architecture and includes feedforward compensation to handle wide-ranging flow rate variations.

[0061] 1. System Overview and Control Strategy Control objective: To control the output oxygen humidity (`H_out) between 80%RH and 95%RH, under varying flow rates (F) of 1L / min-10 L / min and temperature setpoints (T_set) of 25°C-41°C. Flow rate F is the primary disturbance, significantly impacting humidity and therefore requires feedforward compensation.

[0062] 2. Control architecture design: feedforward + cascade PID control.

[0063] Outer loop (main controller): Humidity PID controller. The input is humidity error, and the output is the desired water temperature setpoint T_setpoint.

[0064] Inner loop (secondary controller): Temperature PID controller. The input is the water temperature error, and the output is the heater PWM duty cycle U_pwm.

[0065] Feedforward compensator: Based on the real-time flow rate F, a basic PWM value U_ff is directly calculated and superimposed on the inner loop output to quickly cancel out flow interference.

[0066] 3. System Mathematical Model (Basic of Feedforward Compensation) (1) Study on the linear relationship of related elements Following existing clinical oxygen therapy nursing guidelines, this study investigated the correlation between four factors: oxygen input flow rate, humidifier 602 temperature, output oxygen humidity, and output oxygen temperature, under oxygen therapy orders of low flow rate (1L / min-2L / min), medium flow rate (3L / min-4L / min), and high flow rate (5L / min-6L / min). A precision water bath (temperature error ±0.1℃) was used as the heating tool, and a precision thermometer and hygrometer (temperature error ±0.1℃, humidity error ±0.1%RH) were used as the measuring tools. A humidifier bottle containing 150ml of humidifier 602 was fixedly immersed in the thermostat, and an oxygen cylinder was used as the output gas source. At each oxygen input flow rate value, the humidity and temperature at the end of the nasal cannula connected to the oxygen output port of the humidifier bottle were measured in 1℃ increments. Three experimental cohorts were used, and over 580 sets of actual test data were collected. Some of the experimental data are shown in the table below.

[0067] Experiments revealed that, under the premise of using the same oxygen input flow rate and the same specification of oxygen guide tube 605 (i.e., the degree of bubble dispersion of input oxygen in humidifying liquid 602 is the same), the output oxygen maintains the set humidity and temperature with an approximately linear relationship to the temperature and flow rate of humidifying liquid 602. As the oxygen input flow rate increases, the humidifying liquid 602 needs to provide a higher temperature to ensure that the output oxygen humidity or output oxygen temperature is maintained within the set range.

[0068] (2) Based on the linear relationship of "flow rate-water temperature-humidity" obtained from the experiment, establish a feedforward lookup table or formula: U_ff = base_U + K_ff * (F - F_base) in: F_base: Baseline flow rate (e.g., a set baseline flow rate of 3 L / min). base_U`: The empirically derived baseline PWM value (e.g., 60% based on experimental measurements) at the baseline flow rate and target humidity. K_ff`: Feedforward compensation coefficient (for example, according to experimental measurements, a feedforward compensation coefficient of 5.0% / L / min means that for every 1L / min increase in flow rate, the PWM needs to be increased by about 5% to compensate). (3) Parameter tuning process Determine the feedforward parameters (BASE_PWM_FF, K_FF): Set the system to open loop, comment out the PID calculation, and only keep the feedforward.

[0069] Set a fixed target humidity (e.g., 90%RH), and manually adjust BASE_PWM_FF to keep the humidity stable at 90% when the flow rate is at FLOW_BASE (e.g., 5L / min).

[0070] Change the flow rate (e.g., to 2 L / min and 8 L / min) and adjust K_FF to minimize humidity changes. K_FF is generally a positive number.

[0071] Tuning the inner loop (temperature loop) PID: Fix a flow rate and humidity, and disable the outer loop (directly give the inner loop a fixed T_setpoint, such as 35°C). Use the Ziegler-Nichols method or trial and error to tune KP_TEMPERATURE, KI_TEMPERATURE, KD_TEMPERATURE enables the water temperature to reach the set value quickly and steadily, without overshoot or static error.

[0072] Tuning the outer loop (humidity loop) PID: Enables the entire cascade system. The outer loop parameters are typically much smaller than the inner loop parameters because the humidity response is slower. First, set KI_HUMIDITY and KD_HUMIDITY to 0.

[0073] Increase KP_HUMIDITY until the system starts to oscillate slightly, then decrease it to 60%-80%.

[0074] Gradually add integral KI_HUMIDITY to eliminate steady-state error.

[0075] 4. Write a C language PID program and burn it into memory. The control program can switch different PID parameter groups according to different flow ranges to achieve better control.

[0076] Example 5: One method for establishing oxygen delivery status diagnostic data based on flow rate and pressure data. 1. Research and data acquisition of real-world pressure safety data According to GB 50751-2012 "Technical Specifications for Medical Gas Engineering", the terminal oxygen pressure in central oxygen supply systems for general wards should not be lower than 0.2 MPa, and the terminal pressure for ventilators should not be lower than 0.4 MPa. This study used oxygen cylinders as the gas source, with an output oxygen pressure of 0.3 MPa ± 0.05 MPa. The experimental method involved connecting a precision pressure gauge (error ± 0.01 kPa) to the output path between the humidification bottle and the nasal cannula. Pressure values ​​were measured using the precision pressure gauge under normal oxygen output and when the tubing was folded (using a natural folding method). A flow sensor (error ± 0.2 L / min) was connected to the output port at the end of the nasal cannula. Test flow rates were set according to the clinical oxygen therapy nursing guidelines: low flow (1 L / min-2 L / min), medium flow (3 L / min-4 L / min), and high flow (5 L / min-6 L / min). Each flow rate was tested three times, and the average value was calculated. Some of the experimental data are shown in the table below.

[0077] The collected experimental data revealed that when oxygen was output normally within the range of 1L / min to 6L / min, the output pressure was between 0.093KPa and 0.239KPa, indicating that the pressure within the gas delivery pipeline was at an extremely low level under unobstructed output conditions. However, when the oxygen delivery pipeline was folded in half, the oxygen flow rate decreased significantly, with a reduction of 33% to 55.17%; while the pressure within the oxygen delivery pipeline increased dramatically, exceeding 328.96%. This demonstrates that the changes in pressure and flow rate were highly significant and recognizable.

[0078] 2. Based on the preliminary experimental results, establish a feedback control algorithm for flow rate and pressure factors. The central processing unit dynamically acquires the pressure parameters output by the output medium sensing module 40 and the flow rate value output by the flow control unit 20, compares them with the safety thresholds built into the control program, and generates oxygen delivery status diagnostic data.

[0079] (1) Flow abnormality warning: Based on the initial flow value set by medical staff on the human-machine interface 50, when the flow rate drops by 30%, the central control unit instructs the flow control unit 20 to increase the oxygen output. If the flow rate cannot be restored to the set initial value after adjustment, the central control unit will give a tube blockage prompt or warning message.

[0080] For example, the initial setting is 3L / min. When the central control unit senses that the actual output oxygen flow rate has dropped to 70% of the set value (≤2.1L / min), it will issue a safety warning. When the actual output oxygen flow rate further drops to 60% of the set value (≤1.8L / min), it will issue an alarm warning and require manual intervention.

[0081] (2) Pressure Anomaly Warning When the actual output oxygen flow rate drops to 70% of the set value and the pressure in the oxygen delivery pipeline increases to 0.03 kPa, the central control unit will issue a safety warning, indicating the risk of pipeline blockage.

[0082] When the actual oxygen output flow rate drops to 60% of the set value and the pressure in the oxygen delivery pipeline increases to 0.06 kPa, the central control unit issues an alarm, warning of the risk of pipeline blockage and requesting manual intervention. Simultaneously, it issues a sixth control command to the flow control unit 20 to adjust the oxygen output flow rate, including reducing the oxygen output flow rate and closing the oxygen output valve.

[0083] (3) Early warning of abnormal gas supply status When the output oxygen flow rate drops to 60%-80% and the pressure in the gas pipeline does not change significantly, it indicates that the oxygen supply pressure or supply volume at the oxygen source is insufficient. The central control unit will use sound, light, and electricity to prompt or warn of the risk until manual intervention is performed and the prompt or warning is eliminated.

[0084] The above figures and embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and such modifications or substitutions should be covered within the scope of the claims of this application, and do not constitute any limitation on the scope of protection of this application.

Claims

1. A remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control, comprising a flow control unit (20), a blood oxygen monitoring module (30), an adjustable humidification module (60), an output medium sensing module (40), a memory, a communication module, a central processing unit, and a human-machine interface (50); characterized in that: The central processing unit is electrically connected to the blood oxygen monitoring module (30), the output medium sensing module (40), the adjustable humidification module (60), and the flow control unit (20), and is configured by the central processing unit to form a feedback control loop that includes blood oxygen, flow rate, humidity, temperature, pressure, or oxygen concentration. It dynamically senses and regulates the flow rate, humidity, temperature, pressure, or oxygen concentration of the output oxygen so that the flow rate, humidity, temperature, pressure, or oxygen concentration of the output oxygen is stably maintained within the target range.

2. The remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control according to claim 1, characterized in that: The output medium sensing module (40) is used to monitor the physical parameters of the output medium in real time and feed them back to the central processing unit. The output medium sensing module (40) includes one or a combination of humidity sensor, temperature sensor, pressure sensor or oxygen concentration sensor.

3. The remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control according to claim 1, characterized in that: The adjustable humidification module (60) is a device for humidifying or heating the oxygen supplied to the patient. The adjustable humidification module (60) is controlled by the central processing unit, and its humidification amount or heating power is adjustable and controllable.

4. The remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control according to claim 1, characterized in that: The adjustable humidification module (60) includes a humidification container (601), a humidification liquid (602), an output control element (603), and a connection circuit (604).

5. The remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control according to claim 1, characterized in that: The output control element (603) is an electronic component that uses humidifying liquid (602) to humidify or heat oxygen and increase the humidity or temperature of the output oxygen. The output control element (603) is controlled by the central processing unit. The output control element (603) is set on the inner wall of the bottom of the humidification container (601) or at the tail of the oxygen guide tube (605).

6. The remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control according to claim 1, characterized in that: The output control element (603) is a combination of a heating element and an ultrasonic atomizing plate. The heating element increases the oxygen output temperature, and the ultrasonic atomizing plate increases the humidification rate and humidity. The oxygen heating or humidification is controlled separately according to the set target value.

7. The remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control according to claim 1, characterized in that: The central processing unit control program allows for a humidity control range of at least 40%RH-100%RH and a temperature control range of at least 20℃-41℃.

8. The remote oxygen therapy monitoring system with multi-parameter monitoring and multi-modal control according to claim 1, characterized in that: It also includes a carbon dioxide monitoring module, which is electrically connected to the central processing unit. The sampling port of the carbon dioxide monitoring module is located around the patient's exhalation port to dynamically collect the carbon dioxide concentration in the patient's exhaled airflow, and feeds back the acquired end-tidal CO2 concentration, partial pressure (ETCO2), and carbon dioxide curve to the central processing unit.

9. A control method, characterized in that: While executing the blood oxygen-flow feedback control loop, or the blood oxygen-oxygen concentration feedback control loop, the central processing unit also executes the output medium closed-loop control loop. The execution of the output medium closed-loop control loop includes: The central processing unit receives real-time temperature, humidity and pressure data sent by the output medium sensing module (40); The central processing unit compares the acquired monitoring data with the respective preset target values; Based on the comparison results of humidity or temperature data, the central processing unit generates a fifth control command for adjusting the adjustable humidification module (60), adjusting the humidification rate or heating power of the output control element (603) so that the output oxygen humidity or temperature reaches and is maintained within the preset target range.

10. A control method according to claim 9, characterized in that: Based on the comparison results of flow rate and pressure data, diagnostic data of oxygen delivery status is generated; when the output flow rate decreases and the pressure in the oxygen delivery pipeline increases, it is diagnosed as an abnormal oxygen delivery status. Abnormal delivery status includes poor ventilation caused by pipe blockage or other reasons. The human-machine interface (50) gives prompts or warnings and generates a sixth control command for the flow control unit (20) to intervene and adjust the output oxygen flow rate. The sixth control command for the intervention and adjustment of the oxygen output flow rate includes reducing the oxygen output flow rate or closing the oxygen output valve.

11. A control method according to claim 9, characterized in that: When the central control unit does not issue a second control command to reduce the flow rate, but the output flow rate drops arbitrarily and the pressure in the oxygen pipeline is normal, it is diagnosed as an abnormal oxygen supply status at the gas source end. The abnormal oxygen supply status includes insufficient oxygen supply or insufficient supply pressure, and the flow control unit (20) generates a seventh control command to increase the oxygen output flow rate. If the abnormal oxygen supply status is not eliminated after the seventh control command is executed, the human-machine interface (50) will give a prompt or warning, requiring manual intervention.

12. The control method according to claim 9, characterized in that: The central processing unit automatically adjusts the oxygen output based on the end-tidal CO2 concentration or partial pressure (ETCO2) to maintain ETCO2 close to normal levels. At the same time, it controls the oxygen output in a pulsed manner according to the carbon dioxide curve, outputting oxygen normally when RSP is the inspiratory phase and pausing oxygen supply when PQR is the expiratory phase, thus saving oxygen consumption.

13. A control method according to claim 9, characterized in that: The executed blood oxygen-oxygen concentration feedback control loop includes: the oxygen concentration adjustment range is 21%-100%; the central processing unit receives real-time SpO2 data sent by the blood oxygen monitoring module (30); compares the real-time SpO2 with the preset target SpO2 range; if the real-time SpO2 is lower than the target range, a third control command to increase the oxygen concentration is generated and sent to the flow control unit (20); if the real-time SpO2 is higher than the target range, a fourth control command to decrease the increased oxygen concentration is generated and sent to the flow control unit (20); if the real-time SpO2 is stably maintained within the target range, a sixth control command to maintain the current increased oxygen concentration is generated.

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