Ultrasonic Endoscope Digital Imaging System

The ultrasonic endoscope imaging technique for medical diagnosis plays animportant role in the detection of human alimentary canal and other parts of the bodybecause of its non-destructive feature and the ability of potential lesions detection.However, nowadays the core technology in this field is mainly monopolized byforeign enterprises. Therefore, in order to fill the gaps in the medical ultrasonicdetection products in the domestic field and promote the steps of the development andpopularization of the endoscopic ultrasonography detection technology in our country,this paper designed an ultrasonic endoscope digital imaging system. The imagingsystem used the FPGA as the core device and realized many functions, such as thedata processing which compatible with multi frequency ultrasonic probes, thereal-time display of high resolution image and the gain compensation control functionwhich is an essential feature for ultrasonic imaging system.The main work of this paper is shown as the following:Make the scheme of the ultrasonic endoscope digital imaging system. UsingFPGA as the core device of the system and using USB2.0as the interfacebetween FPGA and host computer to transmit the image data and the commandcodes respectively.Design the digital circuit of the ultrasonic imaging system, which consists of thedata acquisition circuit, the gain compensation circuit, the PING-PONG cachescircuit, the USB2.0interface circuit and so on.Design the program of the ultrasonic digital imaging system. Based on thesynchronous of the system, coding the data processing module capable ofvariable probes with different frequency, the coordinate transformation modulewith CORDIC algorithm which satisfies the real-time display, the USB2.0communication module and the gain compensation control module.Complete the USB2.0driver design between the ultrasonic digital board and thehost computer, realize the real-time display of the ultrasound images and thedownload receiving of the control signal.Research the method of coded excitation and side-lobe suppression, design themismatched filters to reduce the side-lobe of the ultrasound coded echo. Design the S compression curve to achieve a reasonable data compression.Build a complete ultrasonic imaging experimental platform, using beaker andtarget lines as the detecting material, finally get the correct ultrasound image andrealize the real-time display and the control of the whole system.