The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 1997
Filed:
Mar. 28, 1996
Alfred Dean Forbes, Palo Alto, CA (US);
Eric D Helfenbein, Sunnyvale, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An apparatus and method for the filtering of signals collected during a period that includes a quiet ('signal-free') epoch and an event epoch is disclosed. The apparatus includes a means for generating electrical digitized signals of the event episode, memory for receiving and storing the digitized signals of the event episode, an event detector for determining the event epoch and the quiet epoch of the event episode in the digitized signals, a spectrum analyzer to analyze the power spectrum of the digitized signals of at least one event episode, an estimator to estimate electromagnetic interference (EMI) based on the digitized signals of the quiet epoch and the frequencies obtained in the spectral analysis; and a subtractor to subtract the estimated EMI from the digitized signals of the event epoch. The resulting signals are signals of the event epoch with reduced EMI. The apparatus uses basis function(s) at one or more dominant frequencies determined from the spectral analysis to curve-fit data of the quiet-epoch signals to generate the EMI estimate.