The Design And Implementation Of Quantitative Detection For Immuno-Chromatography Based On FPGA Control

Immunochromatography testing technology has advantages of high sensitivity,strong specificity,quickness and simplicity,which is widely used in medicine testing,biological detection,environment protection,food security inspection and other fields.With the universal application of EDA electronic technology in various fields,immune-chromatography detector is developing towards specialization,intelligentialize,miniaturization,integration,integration and one-chip.Both immunochromatography detector at foreign market and current immunochromatography quantitative determination technology around the world are applying existing processors such as single chip,ARM and DSP in system control and management.It requires to re-arrange terminal functions,update design of peripheral circuit or even alternate chips when adding customization function or updating hardware modules.Consequently,this would constrain the flexibility of system updating,prolong development cycle and increase R&D costs.In this paper,it summarizes the current situations of domestic and foreign immunochromatography quantitative determination technology and analyzes the merits of FPGA processor.FPGA technology have been applied to immunochromatography detecting system,which built a immunochromatography quantitative determination system with high sensitivity,perfect consistency and excellent accuracy.This system mainly consists of data-collection and data-processing module.Thus,detailed researches of this work are as follows:(1)To analyze the principle of fluorescence immunochromatography quantitative determination and builds optical measurement device based on the fluorescence characteristics of samples to be tested.To design front-end amplifier circuit,magnifying nA current conversion to V-level voltage and transferring to A/D converter to obtain fluorescent digital signal.(2)The data acquisition module of immunochromatography was designed to drive the A/D chip and the motor.The module includes the control unit,the RAM storage unit,the A/D driver unit and the motor driver unit.The working procedure is to have synchronous sampling by A/D chip at every rotation of motor,then store the original collection data in dual port RAM.(3)To analyze original fluorescence signal and build immunochromatography data-processing module,eliminating noise in its one-dimensional median filter at first.Then in light of the waveform characteristics of fluorescence signal,select peak value as flag value and put forward peak detection algorithm and background basic value identification.Finally,the results was computed by floating number divider.(4)Simulation and verification:ModelSim software and SignalTap ? were used to perform fast functional simulation and real-time logic verification in the system of immunochromatography detection.After the system was downloaded to the development board for debugging,the detection results of the immunochromatographic strips with different concentrations were tested,and the performance of the detection system was analyzed.The detecting system can collect and process the fluorescence signal of immunochromatographic strip.The experimental results show that the concentration of the tested sample is linear with detection result,and the linear correlation coefficient R2>0.99.Morever,the linear detection range of the system is 1.95-256mg/mL,the minimum detectable concentration is 1.95mg/mL,and the repeatability of CV value is less than 5%,which can meet the actual testing requirements.