Research And Development Of Ventilator Software Based On Customized Android Platform

As an important emergency machine which provides life support, ventilator has been continuously developed and improved since the early twentieth century. Intelligentialize and informatization are important trends of ventilators. Android, as an open source operating system, has extensive application space in medical field. With the combination of Android system, Traditional medical equipment would gain the capability of mobile network access, rich graphical interfaces and decent hardware compatibility. The research and development process of customized Android platform based ventilator software is introduced in this thesis. The software which runs on an embedded ARM platform, has sufficient human-machine interface and full function of ventilator monitoring. It satisfies the needs of actual use of ventilator.First, the function and performance requirements of ventilator software are discussed. Aiming to take advantage of this platform and improve the ventilator function, new requirements are elicited, such as graphic interface optimization, combination of touch screen and external device input operation and support of mobile storage.Second, the Android system tailoring, customization and optimization procedure is introduced. After analyzing the system booting process and system service, these unnecessary services and applications are removed. System booting animation and home application are customized as needed. Preloaded classes are reduced in order to accelerate the system startup speed. After system optimization, memory usage is reduced by 44.19%. The Space occupation of file system is reduced by 46.45% in directory of/system and user data reduction is 37.85% in directory of/data.Third, the development of external input device drivers is introduced. The necessity and principle of the drivers of physical keys and rotary encoder are discussed. After that, the way to program, compile and call drivers from Android application using JNI and NDK is presented.Fourth, the design and implementation of the application is introduced. Based on the three tier architecture, the application is divided into user interface layer, business logic layer and data access layer. Components called models are used for data exchange between layers. Major work of user interface design and optimization is discussed from three aspects:dynamic interface design, operation optimization and smoothing of real time waveform. The application functions are presented respectively.At last, the software test method and procedure are introduced. Application stability and functional correctness are automatically tested by Monkey and Monkeyrunner. Code defects are fixed and the stability of application is improved. Application performance is analyzed using Traceview. Performance testing and optimization procedure is introduced. Memory leak is detected and corrected using MAT.