| Publication: J. Lariviere, T. Mussivand and R.A. Goubran, "Effects of Thrombus Simulants on Acoustic Characteristics of Artificial Heart-Valves". |
| Abstract: Thrombus simulants were attached to the inflow valve housing and in-vitro sound recordings were made of mechanical aortic valves in a mock circulatory loop driven by a pulsatile artificial heart (ventricle). The valves were isolated from the ambient sound by means of a semi-anechoic chamber. Nine trials of .60 cycles each were recorded and the power spectra within 10 frequency bands (from 0 to 1000Hz) were calculated using pole-zero modelling and Fast Fourier Transforms (FFTs) and submitted to ANOVA (analysis of variance) tests. FFT results showed a significant difference (p < 0.01) in power levels within the 650 to 750Hz band between valves with and without thrombus simulants when blockage exceeded 10% of total flow area. Pole-zero results showed a significant difference (p < 0.05) when blockage exceeded 25% of total flow area. |