This paper presents modelling and simulation of the B-scanner. A particular emphasis is placed on the dynamic focusing method for improving the lateral resolution. The number and delay times of transducer elements and focal depth of the transmitter and the receiver are decided by ultrasonic beam simulation. As a result of the simulation, 8 dynamic focal points are determined. 2-3 mm lateral resolution along the maximum diagnostic depth is achieved by this dynamic focusing method.
And also signal processing by deconvolution method is used to enhance ultrasonic image quality. In this simulation, the axial kernel is evaluated from the Hamming window and the axial beam profile, and the lateral kernel from the Gaussian window and the lateral beam profile. As a result of the above signal processing, the axial resolution is improved by about 40 percents and the lateral resolution by about 30 percents.
