Research Of Signal Reception And Processing System Of Medical Phased Array Ultrasonic Endoscope

Medical ultrasonic endoscope sends the micro ultrasonic probe and electronic endoscope front-end into the human body together. The doctor can observe the surface of the digestive tract with electronic endoscope and the internal tomography information with ultrasound scanning at the same time. With the advantages of non-invasive, non-radiative, accurate diagnosis and high repeatability, it will be used widely.Compared with traditional mechanical rotating ultrasonic endoscope, phased array ultrasonic endoscope can get higher image quality and have longer using life. As a result, we propose an imaging system of medical phased array ultrasonic endoscope, on the foundation of the research on traditional mechanical rotating ultrasonic endoscope. This paper designs the analog receiving system and the digital processing system based on FPGA.The main work is shown below:1. Made the scheme of reception and processing system of phased array ultrasonic endoscope. Firstly, the analog receiving system received multi-channel echo. Then with digital beamforming and digital signal processing, the image data was uploaded to the computer by USB2.0.2. Designed the analog receiving circuit, which consisted of the amplitude limiting circuit, the gate circuit, the filter circuit and the amplifying circuit.3. Researched the digital beamforming technology, and designed the high-precision digital beamformer.4. Designed the digital processing program, which included digital beamforming, quadrature demodulation, digital filter and so on.5. Build experimental system. The results of the echo experiment of beaker and the imaging experiment of iron wires in a water tank proved the feasibility and correctness of the reception and processing system.