A Comparison of Digital Algorithms Used in Computing the Derivative of Left Ventricular Pressure

Five commonly used algorithms for digital differentiation are evaluated to determine how they perform in the presence of 8,12, and 16 bit quantization noise. The algorithms are compared on the basis of rms error between a model derivative of the left ventricular pressure waveform and the approximate results of each algorithm. Algorithms based on interpolating techniques introduced the least amount of error when 16 bit data were used while algorithms based on least-squares data fit methods performed best on the less accurate 8 bit data. Some of the band-limiting characteristics of the algorithms are also discussed.