Time-frequency analysis of clinical percussion signals using Matrix Pencil Method

This paper discusses time-frequency analysis of clinical percussion signals produced by tapping over human chest or abdomen with a neurological hammer and recorded with an air microphone. the analysis of short,highly damped percussion signals using conventional time-frequency distributions (tfds) meets certain difficulties,such as poor time-frequency localization,cross terms,and masking of the lower energy features by the higher energy ones. the above shortcomings lead to inaccurate and ambiguous representation of the signal behavior in the time-frequency plane. this work describes an attempt to construct a tf representation specifically tailored to clinical percussion signals to achieve better resolution of individual components corresponding to physical oscillation modes. matrix pencil method (mpm) is used to decompose the signal into a set of exponentially damped sinusoids,which are then plotted in the time-frequency plane. such representation provides better visualization of the signal structure than the commonly used frequency-amplitude plots and facilitates tracking subtle changes in the signal for diagnostic purposes. the performance of our approach has been verified on both ideal and real percussion signals. the mpm-based time-frequency analysis appears to be a better choice for clinical percussion signals than conventional tfds,while its ability to visualize damping has immediate practical applications. © 2015 moinuddin bhuiyan et al.