Enhancement and Dynamic Time Warping of Somatosensory Evoked Potential Components Applied to Patients with Multiple Sclerosis

A zero-phase, high-pass digital filter at 300 Hz was used to emphasize the higher frequency, smaller peaks of the somatosensory evoked potential (SEP). Using the digital filter, a consistent pattern of peaks was observed in normals. A dynamic time-warping technique was created to align the peaks of digitally high-pass filtered SEP's. Based on this technique, a clinical test for abnormality of the SEP was developed and applied to 25 multiple sclerosis patients. The results showed that three times as many multiple sclerosis SEP's were identified by the dynamic time warping as by the traditional latency measurement.