Ultrasonic Acoustic Probing Based on Gaussian Beam Analysis

Acoustic contrast describes the relationship between a material’s density and the speed of sound through it. Analyzing the difference in phase and amplitude, information about the differing acoustic contrast between materials can be quantified. Prior methods used a scanning acoustic microscope (SAM) which allowed for phase shifts to be identified by reflections but could not actually quantify phase shifts besides 0° or 180°. The new method uses a continuous signal and Gaussian beam analysis to identify more precisely the change in phase and amplitude to analyze the transmitted signal. By keeping the transmitter stationary and probing the receiver, we examine how the phase and amplitude change as the distance between transducers varies (transverse profiles). This approach is believed to have a potential biological application. Because cells are made mostly of water, the acoustic contrast between healthy cells and cancerous cells is difficult to identify using current ultrasonic methods. This testing method could potentially gather more precise data with respect to the slightly differing contrasts between the cells and help better identify the presence and location of unhealthy cells.