Isolating the lung component from the resonant response of the thorax in impact excited resonance by wavelet decomposition

The human thorax resonates when excited by an impulse such as a percussion. Like every structure it has a modal response related to the degrees of freedom of the system. However we excite not just the thorax itself but the underlying tissue groups. We are interested in the lung tissue component since changes in its mechanical properties may indicate some lung condition or disorder. Thus we are required to perhaps isolate, or at least understand which components are effected by the thoracic shell in resonance. Analytical first principle models predict that since we have fundamentally two tissue densities we have two different propagation velocities. This paper presents evidence that more than one system would resonate when a percussion is performed at the sternum manubrium.