Research On Dynamically Filtering Of High-frequency Ultrasonic Signals Based On Distributed Algorithms

Ultrasonic diagnostic apparatus, as one of the four modern imaging equipments, is widely used in clinical. With the development of electronic technologies, miniaturized, intelligent, fully-digital ultrasound systems become the inevitable trend of development. Overcoming defects in the traditional analog equipment, such as sensitivity to interference, unstable performance, low accuracy and so on, the fully-digital ultrasound diagnostic apparatus becomes an important direction of development. Now there are many restrictions in the fully-digital ultrasound imaging devices on marketing, owing to limitations of their own platforms, ultrasonic data processing and ultrasonic imaging technology. There is a lot of room to be improved in processing speed, machine performance, stability, imaging quality and functionality extensions. A detailed discussion on the dynamic filter structure was presented in this paper.Firstly, the important applications of filtering modules in digital ultrasound diagnostic system was analyzed in the paper. Secondly, several critical technologies had been explained, such as basic filter structures, design of filter coefficients, hardware architectures based on Distributed Algorithm and so on. Then with FPGA technology, hardware architectures of FIR filters were designed. By simulation and comparison during various filter structures, it showed that the best filter structure suited to handle high-frequency ultrasonic signal, was the cascade FIR filter structure based on Parallel Distributed Algorithm. With above-mentioned best filter and the method of dynamic input coefficients, the dynamic filter used in the fully-digital ultrasound diagnostic apparatus was designed and downloaded to the system. Then ultrasound images of Ultrasonic body simulation module, the liver and carotid artery were observed. Design requirements to the fully-digital ultrasound system, and good real-time dynamic filtering performances were achieved. Overall speaking, this paper was a detailed and useful exploration to Digital Ultrasound System, and there must be a reference to the associated staff working on filtering.