The Design Of Control Part Of Automatic Biochemistry Analyzer

Biochemistry analyzer is one of the most important diagnosis instrument used in hospitals of all levels. It can detect the content of varies biochemistry indexes which can provide useful information of patients for doctors to make right judgement and use as feedback afer patients leave hospital. Automatic biochemistry analyzer can do sampling, mixing, wiping off interferer, heat preservation, detecting, calculating etc all by itself and it is more and more popular with hospitals for fast speed and high precision.On the basis of refering large numbers of Chinese and English literature, this paper first introduces the background, meaning and development of automatic biochemistry analyzer and figures out the necessary of designing the machine. This paper then presents the principles of the machine besed on the similar products of inside and outside the country.This paper designs the control part of automatic biochemistry analyzer based on its principle and singlechip computer technology, TWI and CAN communication technology. The control part is consist of five modules:sampling,reagent 1 sampling, reagent 2 sampling, stiring and washing. Each module contains two layers: executing layer and controlling layer. Executing layer uses Atmega48 as main controller and controlling layer uses Atmega64. This paper presents the schematic circuit diagram and PCB in detail, writes programs of the controlling part and finally carries out the scheduled function.This paper designs step motor driving module based on motor controller L297 and dual full-bridge driver L298 and uses ATmega48 as main controller.It also designs circuit of liquid surface apperceive of sampling probe based on distribution of capacitance and crash protection. All schematic circuit diagrams and printed circuit boards are explained in detail,all procedures are wrote and finally actualized the functions.This paper provides all procedures of the controlling layer of sampling module, stirring module, washing module, CAN and TWI communications and are proved right after testing.At last, the paper introduces the process and debugging method of the instrument and figures out the points which needs to be improved. The machine achieves its goal through debugging which verifies the reasonableness of software and hardware designing.