High-Speed Image Acquisition System For PS-OCT Based On USB2.0

OCT (Optical Coherence Tomography) is a new optical technology imaging technology based on white light interference. OCT is a non-invasive, non-intervention, high-resolutionand technology which greatly meets the requirements of the medical technology development. With OCT imaging technology used in the eye, skin, gastrointestinal and cardiovascular and other biological tissue successfully, it is gradually recognized by the medical area. OCT system is mainly composed of optical measurement, signal processing modules, synchronization control by FPGA, image acquisition interface. Image acquisition interface used for image data transmission and display.In recent years USB (Universal Serial Bus) has became a widely used interface technology, it has advantages that other bus is incomparable, such as hot-plug, high-speed and stability, low-power and so on.At present USB2.0 standard agreement that the USB bus transfer rate up to 480Mbps which meet need of the bulk data transmission, provides a high-speed data exchange method between computer and peripherals.This text finished the main work as follows:1,Based on the functions and features of new USB2.0 chip EZ-USB FX2LP from CYPRESS, formulate an appropriate data transmission programme, and completed the design of USB2.0 high-speed circuit.2,Used the firmware framework provide by USB device manufacturers, completed the equipment firmware and finished compiling and debugging under Keil CμVision2 environment;In-depth analysis of the WDM,to find the factors affecting the speed of USB, compiler USB drivers and firmware download drivers under Windows DDK environment;Developed OCT image acquisition client program under VC++ 6.0 environment.3,Analysis OCT structure and the impact on system performance. Analysis of the signal transmission process controlled by the FPGA, define the transport protocol of the image data between the FPGA and USB2.0 interface, which combine the OCT system and image transmission interface perfectly.4,Used FPGA as the controller and simulate data source,completed data transmission experiment for USB interface circuits,verified stability and reliability of system. In addition, add USB2.0 acquisition interface to the polarization OCT system, got the multi-wave plate images, and achieve the 8MB/s transmission speed in asynchronous mode.