IMPROVED METHOD FOR DETERMINING TOPLINE AND BASELINE OF WAVEFORMS USING DIFFERENTIATION

• Main Authors: TILDEN, MARK D, BONHAM, BETTY A
• Format: Patent
• Language: English
• Published: 29.04.1992
• Edition: 5
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

An improved method of finding the topline and baseline of a digitized waveform entails smoothing the original waveform, taking the derivative of the smoothed waveform to produce a derivative waveform, smoothing the derivative waveform, identifying the most important peaks in the smoothed derivative waveform, locating the points where these important peaks cross a threshold, for each crossing point recording in a table whether it was crossing the positive threshold or the negative threshold and whether it was crossing that threshold in a positive-going direction or a negative-going direction, and then using the information in this table to classify all of the points on the original waveform into one of the following seven categories: ignore points, topline points, topline-end points, topline-begin points, baseline points, baseline-end points, or baseline-begin points. Then, the topline value is calculated by averaging the points in the topline group unless there are none, in which case averaging the points in the topline-end group and/or the topline-begin group unless there are none in either of these groups, in which case the maximum value of the whole waveform is used as the topline value. The baseline value is calculated by an analogous procedure.