04244376 is referenced by 26 patents and cites 2 patents.

Steady-state evoked potentials from the nervous system, measured on the scalp and elsewhere on the body in response to specific periodic sensory stimuli, contain the fundamental frequency of the stimulus and other waves, and are of the order of 40 dB below potentials due to general electrical activity of the nervous system which may be considered as noise. Medical information revealed by evoked potentials is extremely valuable but is limited by measuring methods of the prior art and by the background noise. In this disclosure the periodic steady-state evoked potential from a periodic stimulus, shifted to a suitable frequency band, is sampled at instants of zero-crossings of the shifted evoked potential, at the Nyquist frequency or greater for the noise frequency band, and the resultant samples of noise are reconstructed in a filter and subtracted from the entire evoked potential, to produce as a resultant the evoked potential substantially free from background noise.

Title
Measurement of evoked nervous system potentials
Application Number
6/119769
Publication Number
4244376
Application Date
February 8, 1980
Publication Date
January 13, 1981
Inventor
Sidney T Fisher
53 Morrison Ave., Mt. Royal, Montreal, Quebec H3R 1K3
CA
Charles B Fisher
2850 Hill Park Rd., Montreal, Quebec H3H 1T1
CA
IPC
A61B 5/04
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