A New Model of Ultrasonic Imaging System Based on Plane Wave Transmission and Angular Spectrum Propagation Principle

A kind of high frame rate (HFR) 2D and 3D imaging method based on array beams, which belong to limited diffraction beams family, was developed about several years ago. Because only one transmission is required to construct an image, this method can reach an ultra high frame rate. Compared with conventional delay-and-sum (dynamic focusing) method, the HFR system is simple because it uses the fast Fourier transform (FFT) algorithm to get image from the received signal. As the HFR method needs array beams as transmit acoustic field, it is difficult to be realized directly in dynamic focusing system. And when constructing image, a special weighting on the received signal is required. So the imaging system is still a little complicated. In this paper, another kind of HFR method is presented. There arc two characteristics in the method. First, the plane wave is employed as transmitting acoustic field, so it is to be realized in dynamic focusing system. Second, the method constructs image in the view of angular spectrum propagation, so the Fourier transform replaces the weighting process in the original HFR method. Computer simulation, which uses experimental data, is performed to verify the method. Results show that images constructed have the same high quality as the original HFR method while the system implementation of the method could be greatly simplified.