The Use of Intrinsic Components in an ECG Filter

The problem of filtering artifact from QRST complexes of ECG records has been approached by the use of a digital, time-varying filter. The optimum form of this filter assuming uncorrelated, zero-mean, additive noise is presented and shown to be equivalent to estimating the coefficients of an intrinsic component expansion of the complex. Results are reported showing that QRST complexes in limb leads of normals may be accurately represented by only eight terms of the intrinsic component expansion. A suboptimum filter is presented and results reported which show that an order of magnitude reduction of the 0.05 to 100 Hz artifact energy in the filtered complex can be achieved.