Research And Design On Electronic System Of Automatic Biochemical Analyzer

Automatic biochemical analyzer is one of essential medical equipments for clinical diagnosis of medical institution. It is used to determine the various biochemical indicators of human body fluids to provide a scientific basis for doctors identifying patient's condition. It is a kind of biochemical inspection equipment which gathers optics, mechanics and electrics in one equipment.Introduce briefly automatic biochemical analyzer and describe the domestic and international development of automatic biochemical analyzer. Describe the working principle, the overall structure, work processes and methods commonly used in biochemical analysis of automatic biochemical analyzer. According to the whole control tasks, establish the control scheme and design the hardware circuit of the control scheme. In accordance with the functional requirements, accomplish the software design of lower computer using C language and assembly language, as well as draw flow charts of software. At last, analyze the reliability of the electronic system.The electronic system of automatic biochemical analyzer has many inputs and outputs, requires stringent operation time sequence and collects real-time data of multi-channel analog signals from current cuvette. Therefore, the system employs full-speed USB FLASH Micro Control Unit (MCU) C8051F340 as the core element to complete the electronic system design, which not only simplifies the system structure but also enhances the system stability and reliability. Detect the optical signal through the cuvette by ultraviolet and visible spectrophotometry. Detect the optical signal with photo diode and AD549, design signal conditioning circuit to improve detection accuracy, and design achieved analog-to-digital converting circuit with AD976A to complete the data collection. The motor drive module converts the microcontroller device commands into corresponding actions of the actuating mechanism. Owing to the reliability of the reaction, temperature should at a constant value and it needs the temperature measure and control circuits. By defining the upper and lower computer communication protocol, send commands down to the lower computer to complete analyze and operation and deliver the collected data to the upper computer by USB. Software development environment is Keil uVision3. Through the adapter U-EC5, debug and download programs into the microcontroller C8051F340. Software adopts the modular design, so the content of each other is independent and the program is written and debugged easily.Through repeated debugging, the functional requirements of the automatic biochemical analyzer electronic system have been tested. And the detection accuracy has been improved.