【摘要】 为了提高超声虚源次序波束形成的成像分辨率，提出一种基于虚源的延时乘累加波束形成算法，即VS-DMAS(delay multiply and sum beamforming based on virtual source)算法.该算法将DMAS的思想引入虚源次序波束形成的第二阶段，利用DMAS算法中相乘耦合运算的特点，充分考虑信号之间的相干性，以抑制低回声区域伪影的产生，提高超声成像的分辨率和对比度.对该算法进行了点目标仿体仿真以及实体数据成像实验.结果表明，相较于常规的聚焦方式，VS-DMAS算法具有更低的旁瓣和更窄的主瓣，能够更好地将点目标从背景噪声中分离出来，随着深度的增加，依然有着较高的成像分辨率.且随着算法中p值适当增大，成像分辨率和对比度均有一定的提升.更多还原

【Abstract】 In order to improve the imaging resolution in ultrasonic sequential beamforming based on virtual source, a delay multiply and sum beamforming algorithm based on virtual source, namely VS-DMAS algorithm, is proposed. The algorithm introduces the idea of DMAS into the second stage of sequential beamforming based on virtual source, taking advantage of the characteristics of multiplication coupling operation in DMAS algorithm, with the consideration of the coherence between signals, in order to suppress the generation of artifacts in low echo areas and improve the resolution and contrast of ultrasonic imaging. The point target phantom simulation and entity data imaging experiment are carried out. The results show that compared with the conventional focusing method, VS-DMAS algorithm has lower side lobe and narrower main lobe and can better separate the point target from the background noise, with the increase of depth as well as a higher imaging resolution. And with the appropriate increase of p value in the algorithm, the imaging resolution and contrast are improved to a certain extent.更多还原