Measurement of visually induced biomagnetic responses
US5027819A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 12, 1990 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Jul 12, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S128/901
- WIPO fieldMedical technology
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.