【摘要】 和传统的高斯聚焦声束相比，有限衍射声束具有较大的声场深度，可以用于医学成像、组织定征、材料的无损检测、多普勒血流检测等许多领域。理论上非衍射声束只能由无限大孔径换能器产生，实际应用中，用有限孔径近似产生的有限衍射声束也具有很大的声场深度。本文介绍了有限衍射声束的产生、各方面特性、及在医学成像、血流估计方面的应用。更多还原

【Abstract】 Limited diffraction beams have a large depth of field and thus have many applications such as medical imaging、tissue characterization、material flaw detection and blood flow detection by Doppler method.Nondiffraction beams colud be produced only by transducer with an infinity large aperture in theory. The experimental results show that limited diffraction beams produced by a limited aperture have desirable large depth of field also. The theory of this kind of beams and their applications in field of medical imaging and blood flow estimation are introduced.更多还原