New time-frequency analyses of EMG and TMJ sound signals

The use of the reduced interference distribution (RID) to obtain improved energy density representation of nonstationary signals in time and frequency is described. Two applications of clinical interest, namely, 3-D graphical presentations of motor unit action potentials (MUAPs) and of temporomandibular joint (TMJ) sounds, have been performed and are presented to show the advantages of using the RID. It is found that the RID gives more detailed and more accurate information about those signals when compared with other methods for time-frequency representation.<>