Study on the influence of a noisy environment on the ECG correlation dimension determination; possible use for noise estimation

It is shown how the determination of the correlation dimension (D/sub 2/), an algorithm which allows the estimation of a nonlinear system degrees of freedom, is affected by the presence of noise. The poor accuracy in computing D/sub 2/ is related to the noise fraction of the signal measurement. A very simple empirical way to adjust the D/sub 2/ value is presented. Some preliminary results on a rough way for the noise fraction estimation are given. This study has been done mainly on a Henon attractor, and D/sub 2/ adjustments have been tried on electrocardiogram (ECG) signals, yielding D/sub 2/ values ranging between 1 and 2, in healthy subjects.<
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