Medical & biological engineering & computing vol:27 issue:1 pages:47-56
An algorithm is presented for the processing of smooth biological signals with an important implicit data reduction. It is a solid basis for an automatic analysis of these signals. The algorithm is based on the approximation of the signals with a linear combination of cubic B-splines. Depending on the parameters, a data reduction of between 8:1 and 12:1 can be achieved. The most important differences from conventional biological signal processing methods are the representation of the signal by the coefficients of the linear combination instead of a series of samples and the analysis by calculations of the time of the appearance of patterns instead of iterative searching. The approximation and analysis of long-lasting multichannel signals can be performed online with a modern microprocessor. Approximating the signal with a linear combination of cubic B-splines with equally spaced knots, according to the linear least-squares criterion gives the desired data reduction and an elegant way to perform an automatic analysis. A window calculation scheme makes it possible to handle very long signals online.