Design Of Automatic Biochemical Analyzer And Control System

Automatic biochemical analyzer is an instrument which can obtain a variety of biochemical indicators via detecting human blood or body fluid samples. Currently, there is a great demand on biochemical tests in society. The device has been widely used in hospitals because it can reduce the workload of medical staff. The technology of the analyzer is complex. Chinese research in this area is late and the domestic products have poor quality. There is a large gap between domestic and foreign. This paper aims to design the control system of an analyzer which performs stable and is easy to operate. It can play a guiding role for the the development of subsequent products.Firstly, the research situation at home and abroad is learned. A design plan is proposed after analyzing the works and overall structure of the biochemical analyzer. Then lower hardware and software are designed in detail. In terms of hardware, the photovoltaic cells are uded as a front-end signal detection unit. STM32F217ZET6is selected as the control core and the processor collects the signal through A/D converter. The large amounts of data are transferred up crew through the USB interface circuit. The RS232circuit is used for debugging and the ethernet circuit is used for remote control. The main board is the key of coordinating other modules to work correctly. Taking the reliability, scalability, real-time and other factors into account, the CAN bus is chosen to communicate modules. On the software side, the three-tier architecture of application layer, driver layer and operating system layer is used. The RT-Thread operating system is chosen for STM32. It provides real-time and multi-tasking capabilities to meet the requirements of complex control. On the basis of the operating system, the drivers for USB and Ethernet communications are realized. The function of the system is divided into multiple parts and each part is achieved by a thread in the application layer.Finally, each module of the system was debugged.Then a series of experiments was conducted. The analysis of the experimental data shows that the instrument performance meets the design specifications.