Cancellation of contact artifacts in a differential electrophysiological signal

1 . A method to eliminate electrophysiological sensor contact artifacts in a composite differential signal comprising the steps of

(a) simultaneously and separately recording noise and a composite differential signal at a recording site;

(b) identifying a transform that may be used to transform the separately recorded noise into an approximation of noise present in the composite signal;

(c) reconstructing the noise present in the composite signal using the transformed recorded noise;

(d) canceling the noise present in the composite signal using the reconstructed noise.

2 . The method of claim 1 wherein the recording step records with a split sensor.

3 . The method of claim 1 whereby the transform and reconstruction steps are done on a synchronized noise block and signal block.

4 . A method for cancellation of local artifacts from differential recordings of electrophysiological signals comprising the steps of

(a) reconstructing a noise contribution to a measured composite differential signal that comprises desired differential signal and noise;

(b) subtracting the noise contribution from the composite differential signal.

(c) providing a representation of the desired differential signal.

5 . The method of claim 3 further comprising the steps of performing a batch least square fitting of noise blocks and removing the fitted noise blocks from the signal blocks.