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:
Jul. 02, 1991
Filed:
Jul. 12, 1990
Duane B Crum, San Diego, CA (US);
Biomagnetic Technologies, Inc., San Diego, CA (US);
Abstract
A biomagnetometer measures the magnetic field produced by the brain as a result of a visual stimulus delivered by a display device such as a cathode ray tube (CRT). The output signal of the biomagnetometer is filtered to remove noise introduced by the operation of the display device itself, such as the repetitive scan signal of the CRT, and the CRT monitor is otherwise operated from DC power to minimize periodic variations that can interfere with the detection of brain signals. The filtering is preferably accomplished using a comb-notch filter. Cancellation coils and shielding are also preferably used to remove a portion of the noise introduced by the display device.