【作者】 李仙琴；

【导师】 王延群； 杨军； 李跃杰； 计建军；

【作者基本信息】 中国协和医科大学 ， 生物医学工程， 2010， 硕士

【摘要】 超声诊断仪作为现代医学四大影像设备之一,在临床中得到了广泛应用。随着电子技术的发展,小型化、智能化、全数字化成为超声诊断系统发展的必然趋势。全数字化超声成像设备克服了传统模拟超声诊断设备易受干扰、性能不稳定、精度较低等缺点,成为超声成像设备的一个重要发展方向。目前国内市场上的数字化超声诊断仪由于自身平台、超声数据处理和超声成像实现技术的限制,在处理速度、机器性能、稳定性、成像质量和功能扩展方面都有很多地方可以改进。本课题就其动态滤波器的结构设计做了详细的讨论。论文首先从理论上分析了滤波模块在全数字超声诊断系统中的重要应用,接着对FIR滤波器设计的关键技术：滤波器的基本结构、滤波系数的设计、基于分布式算法的滤波器硬件结构等进行了详细的阐述,并结合目前广泛应用于超声系统的FPGA技术给出了实现方案。然后通过仿真验证,并对比各种滤波器结构的优劣选出最适合处理高频超声信号的滤波器结构。最后以前面选出的基于全并行分布式算法的级联型FIR滤波器结构为基础,采用动态输入滤波系数的方法,实现了能够运用于现有的全数字超声诊断系统中的动态滤波器,并将其下载到该系统中,对仿组织超声体模块以及肝组织、颈动脉进行图像采集,获得了良好的效果。本设计对全数字超声系统的动态滤波具有良好的实时处理能力,达到了预期的设计要求,从整体上讲是对数字化超声系统的细化而有益的探索,对从事相关滤波工作的技术人员有一定得借鉴意义。更多还原

【Abstract】 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.更多还原