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:
Aug. 13, 2002
Filed:
Feb. 13, 2001
Ilmari Kinanen, Espoo, FI;
Koninklijke Philips Corporation N.V., Eindhoven, NL;
Abstract
In an open magnetic resonance system, pole pieces ( ) on opposite sides of an imaging region ( ) are supported by a ferrous flux return path ( ). During normal operation, environmental disturbances that cause low frequency vertical vibrations in the floor cause corresponding fluctuations in the main field of the magnet. A spacing between the pole pieces ( ) expands and contracts with the vibration causing a strength of the main field to fluctuate. A force transducer ( ) under the magnet assembly measures the magnitude of the vibrations. A vibration analyzer ( ) analyzes the vibrations waveform and calculates compensation for the changes in the interpole spacing. The vibration analyzer ( ) controls one or more of a shim coil ( ) which produces a field equal and opposite to the main field fluctuations, a reconstruction processor ( ) to compensate for magnetic field resonance frequency fluctuations attributable to the main field fluctuations, and gradient magnetic fields applied by gradient field coils ( ).