Research On Ultrasonic Imaging Technology Based On Focused Transducers

Ultrasonic imaging technology can use different acoustic parameters to generate different acoustic images.In this paper,focused transducers are applied in ultrasonic imaging technology,and its acoustic field characteristics are used to improve the detection performance,thereby improving the imaging quality of the ultrasonic technology.The specific theoretical and experimental research contents are as follows:(1)The basic theory of detecting ultrasonic transducers was studied.The acoustic field characteristics of non-focusing and focusing transducers and their effects on ultrasonic testing were analyzed.It is found that the acoustic field characteristics of the focusing transducers will be helpful to improve the detection performance.(2)For ultrasound transmission CT technology,the relationship between the focused slice size of the arc line-focused transducer and its geometric size,and the influence of the size of focus slice on the CT detection were analyzed.The detection system was designed and set up.The projection data were obtained by the scanning mode of equiangular fan beam.FBP and LSQR algorithms were used to reconstruct the image.By comparison,the LSQR algorithm is more universal and its imaging quality is better.The experimental results show that,using the focused transducer and the LSQR algorithm to detect objects,good imaging results with detection resolution reaching millimeter scale can be obtained.(3)For ultrasound scattering imaging technology,a method of target scattering imaging based on a spherical shell focused array was studied.At first,a part of array elements in the spherical shell transmitted the focusing sound waves.After the sound waves acted on the target,the scattering echoes were received by the remaining array elements.The transmitter and receiver arrays were selected randomly to suppress the side lobes.By the three-dimensional automatic scanning detection system,the scattered echo intensity of the focused beam along the surface of the measured object can be obtained,so as to realize the imaging of the target.The computer simulation results show that the above method can effectively suppress the side lobes of the focused beam and shorten the width of the main lobe.The experiment results show that a resolution of sub millimeter level was achieved,obtaining a high contrast image.