Author(s)

K. Hamamoto, T. Nishimura & M. Saito

Abstract

Axial resolution of the pulse-echo ultrasonic image depends on pulse duration. Therefore, the inverse filtering methods have been proposed to improve resolution. However, the centre frequency of the pulse wave shifts lower as it travels in biological media, so that pulse duration becomes longer. In addition to this problem, pulse waves reflected in deep regions cannot be recognized because of the low signal-to-noise ratio. We propose a method using the wavelet transform to improve resolution. The wavelet transform is one of the methods for time- frequency analysis. The incident pulse wave is used as the mother wavelet in th

Keywords