The Development Of Non-Invasive Ventilator Based On Dual Control

In recent years,the incidence of various chronic respiratory diseases has been rising year by year,and the number of patients is also increasing,which poses a great threat to the health of patients and affects their daily life to a certain extent.Ventilators can effectively treat some diseases of the respiratory system,and the non-invasive ventilator has attracted people’s attention and entered more and more People’s Daily life because of its advantages such as simple operation and less trauma to patients.Due to the late start of ventilator in China,and most of the key technologies are monopolized by foreign ventilator companies,the market share is low and there is a certain gap between domestic and foreign products in terms of technology.Therefore,according to the relevant standards of the non-invasive ventilator industry,this topic conducts in-depth analysis and research on its internal core algorithm,and designs a non-invasive ventilator based on dual control.This paper first introduces the background of the research topic and the development history of the ventilator,and then compares the research status of the non-invasive ventilator at home and abroad.By analyzing the working principle of the ventilator and referring to industry standards,the main functional requirements of the non-invasive ventilator are formulated,and the indicators of important technical parameters are stipulated.The non-invasive ventilator developed is based on NXP’s MIMXRT1052 chip as the main control chip of the system in this paper.On this basis,it is equipped with various external functional modules necessary for the non-invasive ventilator to complete the design of the entire hardware system of the non-invasive ventilator.This paper combines the two modes of constant pressure ventilation and constant volume ventilation,and according to the characteristics of the current ventilation modes,the dual control mode is specially designed in this system,so that the non-invasive ventilator can be based on the preset tidal volume dynamically adjusts the treatment pressure to ensure the patient’s tidal volume supply,and can choose a different pressure rise times according to needs.In the aspect of fan control,the position type PID control is adopted,and the PID control parameters are optimized by using genetic algorithm.The stable output pressure of the ventilator is realized,and the pressure overshoot is reduced when the pressure is switched,so that the ventilator has a better pressure control ability.At the same time,this paper also studies and designs some key algorithms of the non-invasive ventilator,including intelligent start,air leakage measurement,breathing trigger and so on.In the software system design of the non-invasive ventilator,this paper transplants the domestic real-time operating system RT-Thread to MIMXRT1052,and uses the task management and scheduling mechanism of this operating system to design and develop the tasks corresponding to the various functions of the ventilator,such as data acquisition,pressure adjustment,key detection,alarm and data transmission,so as to realize the multi-task operation of the ventilator system.In order to verify the technical indicators and performance of the developed non-invasive ventilator,this paper uses the active simulated lung ASL5000 as the main test tool to build a test environment for the ventilator.This paper has conducted a comprehensive and detailed test on the function and parameters of the non-invasive ventilator.The test results show that the main functions of the non-invasive ventilator designed in this project have reached the expected goals,and the parameters have also met the relevant standards.The operation is reliable and pressure output is stable,and the expected design goals have been reached.