Acoustic field simulation for arbitrarily shaped transducers in a stratified medium

An efficient approach to the simulation of the acoustic field from an ultrasound transducer is the impulse response method. A major limitation is the assumption of a homogeneous medium. When the medium contains aberrations, one has to use a direct summation of the Rayleigh integral, since in principle each path from a point on the source to the observation point has a unique time delay and attenuation profile. Using modern work stations, many problems of interest are now feasible to solve with reasonable processing time using a simulator based on direct summation. The method including the delay and amplitude calculations through the layered medium is described. The simulator has been used to find the resulting field after propagation through a layered medium such as a transducer with a dome or a transducer viewing through a layer of fat. Examples of such simulations are given and compared with measurements