(s)
Figure 4: Variation of transmission coefficient with heart dimensions during a cardiac cycle at specific frequencies in the range 1-10 GHz.
It is seen from the CST MWS simulations that there is the same trend of increase (upto 0.3s), maximum at 0.3s (time at which the heart is completely in contracted state) and decrease (from 0.3 to 0.8s) at the specific frequencies. The shapes of variations of transmission coefficients are consistent with the variations of heart size in a cardiac cycle. This is a unique observation for the transmission coefficients (dB) of the UWB signal corresponding to the varying dimensions of heart over one cardiac cycle.