The Research On The Design Of Electrical System Of Full Automatic Biochemical Analyzer

Full automatic biochemical analyzer is one of essential instruments for clinicaldiagnosis of medical institution. It is a kind of biochemical inspection equipment whichgathers optics, mechanics and electrics in one equipment. It is mainly used to determine thevarious biochemical indicators of human body fluids, which provides a scientific basis fordoctors identifying patient’s condition.In the paper, the analyzer is briefly introduced. Then its developments at home andbroad are elaborated, together with its classification, perform principles, overall structure,workflow and biochemical analyzing methods as commonly used.Not only are there a large number of inputs and outputs and strict demands for timingoperation, but also multi-analog signals from the current reaction cup are collected in realtime in the Electrical system of analyzer. Therefore, EP2C8Q208C8N of CycloneⅡ FPGAfamily is used as the core component to control the whole system, which both simplifies thesystem structure and improves stability and reliability of the electrical system. At firstduring the design on automatic sampling system, TC1002and L6203are used to control anddrive stepper motors, with direction signal and subdivision signal set. During the design onoptical path and its detection system, photodiode array S4111-16Q is applied to opticalsignal acquisition to convert optical signal to electric signal by spectrophotometer method.And log114logarithm amplifier circuit is used to calculate absorbance，which simplifies thedesign and enhances measurement precision. ADS8344can finish analog-digital conversion.In order to ensure constant reaction temperature (37℃0.1℃) for reaction, biochemicalreaction support system is designed. Within this system, temperature sensor is used toachieve data acquisition, with Fuzzy PID temperature controller adjusting PWM duty cycleto start the circuit controlling temperature and to drive peltiter semiconductor. Therefore, itcan ensure that the process of biochemical reactions is at the constant temperature. Everyblock is relatively separate, which is convenient to write and debug programmer. Then it isdescribed how to select test methods for different biochemistry quotas and part of testmethods of quotas for some body organ functions.Finally, summary and outlook are given, which contributes to the further study of thebiochemical analyzer.