A numerical model simulating sound propagation in human thorax

Auscultation sounds offer a rich source of diagnostic information to allow for noninvasive detection of various thoracic pathologies. However, recent efforts attempting to use an array of acoustic sensors for diagnostic purposes has seen marginal success owing to the simplifying assumptions employed in their models. In particular, factors such as heterogeneity of medium, shear wave contributions and extreme near-field conditions are often ignored. This work presents a 2D numerical model capable of simulating the propagation of intra-thoracic acoustic sources that can assist in development of improved diagnostic schemes. Specifically, the model employs a finite-difference time-domain (FDTD) scheme to solve the viscoelastic wave equations while taking the intrinsic anatomy and associated stiffness properties of various tissue structures into account. The simulated sound distribution maps can then be employed to develop better inverse problem techniques for disease diagnosis.