Research Of Multi-channel Transmission And Signal Reception System Of Phased Array Ultrasonic Endoscope

The endoscope ultrasound system(EUS) imaging technology for medical diagnosis plays an important role in the detection of human gastrointestinal diseases. The EUS imaging technique is considered one of the best detection methods in the nearly gastric cancer for its non-destructive, painless and unique ability to probe the mechanical properties of tissue. China's EUS Instruments are mostly imported, which make the EUS detection costly for patients. In order to change the monopoly of imported products and promote the popularization of the EUS imaging detection technology in our country, this paper designed a phased array ultrasonic endoscope imaging system.All the work in this paper is based on the research of the rotating scan ultrasonic imaging system of single element array done in my laboratory. In this paper, the phased array EUS used an array probe as the transmitting and echo receiving element, and the FPGA as an controller. The multi-channel transmission circuit is designed and the FPGA was set to realize the function of timing control and echo data acquisition as well as the beam scan control. Finally the echo data was sent to the computer, in use of further study of phased array imaging algorithm for higher resolution.The main work of this paper is listed as the following:·Make a scheme of the phased array ultrasonic endoscope imaging system. Using FPGA as the core and making an circuit with 16-channel parallel launch excitatting the array probe and 1 channel receiving the echo.·Design the multi-channel transmitting circuit of the phased array ultarsonic imaging system, which consists of the phased control circuit, the excitation pulse trasmitting circuit, high voltage drive with the hige voltage monitor circuit and power conversion circuit. The circuit is able to launch 16 channel parallelly and the excitaion pulse amplitude is adjustable from 0 to 200 V, the time delay accuracy between channels is 0.5ns.·Design the program of the phased array ultarsonic imaging system using Verilog HDL, Making the FPGA control the whole system to send the ultrasound wave and transmite the echo data to the computer by USB2.0.·Build the phased array ultrasonic imaging experimental platform with several wires in a water tank as the detectiong material. Use the Field II in MATLAB to process the data obtained to verify the whole system...