Study On Digital Beamforming Of Ultrasound Apparatus

Medical ultrasound imaging technology and X ray imaging technology,magnetic resonance imaging and nuclear medicine imaging technique are considered for four major medical imaging technology so far,which has become the indispensable role of medical imaging technology.Compared with other imaging techniques,ultrasound imaging technology has received wide attention from all walks of life and the application due to the advantages of simple operation,safe,rapid,painless and no measurement accumulation error.Beam forming technique has been the focus of ultrasound imaging system,which directly affects the final quality of the ultrasound imaging system.To this end,it is very important to study the new and high efficiency beam combination technology,which is of great significance to improve the overall quality of medical ultrasonic diagnostic equipment in China.The method of delay stack beam synthesis is the most widely used.However,there are some problems,such as the beam scanning dead zone and the storage capacity,which are too large to be gathered,which limit the further improvement of the image resolution.For this purpose,the following aspects are studied:(1)The combination method of subsection emission and point by point clustering is proposed,which is used to transmit the dynamic aperture in the launch part,and the receiving part is assembled by point by point,which improves the lateral resolution.(2)In this method,a linear scanning method is proposed,which is based on the dynamic aperture technique,which can minimize the displacement of the scanning line,covering the scanning area as far as possible.(3)The method of storing the delay parameters of the adjacent displacement is proposed.By studying the relative sound difference,the time delay parameters are decomposed and compressed.In the process of focusing synthesis,the delay parameters are generated in real time,the algorithm can reduce the complexity of multiplication and reduce the hardware resources which reduced the storage capacity.(4)High speed LVDS serial interface is designed.By external clock chip to ensure multi-channel AD conversion circuit synchronous sampling.(5)The hardware system based on FPGA is designed,the design of the front end system of ultrasonic beam is finished,and the transmitting and receiving of ultrasonic beam is realized,which prepare for subsequent data processing.(6)Set up the ultrasonic hardware platform based on FPGA,data acquisition.Through the analysis of MATLAB data,compared the effect of the image.