The Data Acquisition And Pretreatment Of Dynamic Spectrum Based On Linear CCD And FPGA

The detection of blood component is the important method to keep fit and disease diagnosis. And non-invasion diagnosis based on the near infrared spectrum has a bright future, especially the method of Dynamic Spectrum (DS), with which we can remove the affect of the individual discrepancy and the measurement conditions. However, because of various components of blood and severe spectrum overlap, and DS needs high precision, so how to get perfect DS becomes the key to if we can implement the non-invasion detection of component blood.DS can be obtained by the Photo pulse PlethysmoGraphy. The system of data acquisition must be higher precision, sensitivity and speed, and need to process large data. So the ability of control and processing is called. We designed data acquisition and pretreatment of DS based on linear CCD and FPGA.According to so weak signal in DS detecting system, we select high feature linear CCD-IL-C6-2048C, and design time and driving circuit for it. In order to acquire CCD's signal, we select 18-bit ADC-AD7674.We not only need to design the time of CCD and ADC, but also implement log and FFT arithmetic, and acquire and control data. We select high speed and strong controlling FPGA and Nios II microprocessor. And we make a data acquisition and pretreatment system based on FPGA and Nios II. FPGA is high speed, programmable and flexible configured, and Nios II can be added into FPGA. All these make easy to design the time of CCD and ADC, and to implement log and FFT arithmetic.The data acquisition system must be higher precision and speed, so it's hard to design with hardware. However, we designed the system successfully. It met the request theoretically. In order to validate the system, we did various experiments to validate our system. It improved our system meet expecting request, and is suitable to the detecting of DS. The system which is made up of FPGA and Nios II is able to process large data and can control all the devices, which make our system programmable. It's available to make our system upgrade.