Design And Implementation Of Biochemistry Analyzer Control System Based On ARM

This paper is an improving project of the sub-subject of automatic biochemical analyzer’s develop (Subject Number:2004BA706B05) which is under the support of the National Science and Technology Department’s Tenth Five-year Plan. The sub-subject is the design of800tests/hour full-automatic biochemistry analyzer control system. Automatic biochemistry analyzer is a biochemical testing equipment integrated with optics, machine and electricity technology. It provides physicians with important scientific bases in disease diagnosis, treatment and prevention.In this paper, the principle of the biochemistry analyzer, classification and developing state at home and abroad are repesented. The composition and the working process of the automatic biochemistry analyzer are also described. On this basis the focus on the improving design and implementation of the electronic control system of the automatic biochemistry analyzer NSA-800is brought into. In this new scheme, one microcontroller ARM replaces multiprocessor and the working process of the biochemistry analyer runs under the control of the real-time operating system μC/OS-Ⅱ. Control system design has two parts including system circuit design and software design.In the aspect of hardware design, the design uses ARM, which is the faster and the better electronic controller in performance, as a whole core chip. This makes μC/OS-Ⅱ embedded operating system and software based on this run smoothly. In this paper, the serial communication module, the stepping motor drive system module, the location signal module, the temperature control module, the data acquisition module and other modules in the automatic biochemistry analyzer electronically controlled system are presented.In the aspect of software programming, the design bases on μC/OS-Ⅱ which is hard real-time embedded operating system and whose core is concise. The article focuses on how to use a timer to achieve many virtual timers in order to generate pulse to drive stepping motors, how to control stepping motors in micro-step method, serial communication with PC, data acquisition and the programming of temperature control.Based on the design of hardware and software above presented, the scheme has realized by debugging at Examination Division of Medical Electronics in Neusoft Group. The debugging results show that:under the scheduling of μC/OS-Ⅱ ARM is capable of communicating with PC, a uniform movement, an accelerating movement and an decelerating movement of the stepping motor movement are achieved, the temperature of reagent discs and reaction plates are controlled stably, and the data acquisiting module is initially debugged well. Practice has proved that the scheme of the system design in which one chip ARM replaces multiprocessor (AVR processors) to control eliminates the need for a large number of external bus and the original chips that support the RS485agreement, and reduces the number of processors. Accordingly, reliablity has been improved and cost and power consumption of the system is significantly reduced. To sum up, the automatic biochemistry analyzer electronic system based on ARM and μC/OS-Ⅱ is reasonable, feasible. It is a perfect scheme for control system upgrade. The prespects of the product upgrade scheme are also put forward.