Monitor Real-time Linux System

Patient monitor is a kind of clinical equipment, which can get the physiologically parameters'information from module with different frequencies, shows waveforms on the screen synchronous, alarms those parameters out of limits at one time, help physician and nurse to make a quick decision.Obviously, Linux, as a common universal operation system, has un-replaceable advantages, however, when Linux apply in embedded systems, it needs to modify real time to get with rapid interruption. In this thesis, a research has been made on a type of GE Healthcare patient monitor, do effort on enhance the real time of Linux which embedded in patient monitor.The methods this thesis used are in two ways:one is patching Linux inside, changing Linux's kernel data/dispatch function/interruption; second is design a co-processor to deal with the real time processes, called UMBC, USB module bus converter.UMBC is a data collection module, collect each physiologically parameters' information. Depending on different frequencies of parameters, UMBC catches them separately, and send one package to Linux every 10ms by USB(if there isn't a cardiac defibrillation signal).In hardware design, this thesis choose chip AT91SAM9G10 as the major chip of co-process UMBC, and design the related circuits, like power/timer/USART/USB.In software design, this thesis does the major work on 4 parts of programs. Kemimain is the main program which runs on UMBC, design for initialization of the kernel, the interruption and hardware resource, and enter the infinite task execution loop. Umbcmagr use to control communications with Linux. Mbhost use to control 485 module bus with module. Difibmaker is an independent program to check if the signal is a cardiac defibrillation signal. Anytime find this signal, don't need to follow the 10ms communication rules.The result of the research shows the methods of enhancing the real time of Linux is possible and effective. UMBC helps Linux to process the work of collecting physiologically parameters'information, lows the occupation of CPU, and prevents frequent interruptions causing overload.