Study On Core Algorithms Of Ultrasound Imaging Based On FPGA

Recently the continuous development of computer technology and integrated circuitspromotes the development and perfection of the all-digital ultrasound diagnosticapparatus. The essential purpose to improve the core algorithms inside the digitalultrasound diagnostic apparatus under the hardware environment of FPGA is mainly toprovide a fast imaging system as well as better quality ultrasound images, which will laya basis for further study of3D ultrasound in medicine.After shortly explaining the basic framework of all-digital ultrasound diagnosticapparatus, firstly I design the dynamic band-pass filter whose central frequency ischanged with the scan depth based on the phenomenon that ultrasound will attenuatewith the increasing scan depth. Meanwhile, to lower the error brought by square rootoperation using IP core in FPGA and reduce the computational complexity, themagnitude extraction of the digital quadrature is combined with logarithmic compression.Each single-channel digital RF echo-signal is processed into8bit gray scale pixelaccording to these four steps. Secondly, the introduction focuses on the CORDIC andtwo-dimensional linear interpolation algorithm inside the digital scan converter (DSC).Corresponding improvement in the accuracy is made.Then the display plane includingthe effective imaging area and the data storage is designed. Finally, according to thevisual residual image and results of quantitative evaluation indexes (PSNR and SSIM),the correctness and feasibility of this design is verified by comparing MATLAB withFPGA. Furthermore, a summary of research work and suggestion about someimprovement is made.