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:
Apr. 17, 2001
Filed:
Aug. 28, 1998
John V. M. McGinley, London, GB;
Ian R. Young, Marlborough, GB;
Gordon D. DeMeester, Wickliffe, OH (US);
Ilmari Kinanen, Espoo, FI;
Picker International, Inc., Highland Heights, OH (US);
Abstract
A pair of annular magnets (,) generate a vertical magnetic flux field through an imaging volume (,). The flux is focused by a pair of Rose rings (,) of high cobalt steel. A high order shim set includes a plurality of permanently magnetized or magnetized iron rings (,) which cooperatively interact with the magnet assembly to optimize the homogeneity of the magnetic flux through the imaging volume. One of the permanent magnetic rings (,), is mounted with an opposite polarity relative to the others. The magnetized rings are mounted in a non-ferrous, electrically insulating support structure (,) such that gradient coils (,) can be positioned behind the permanent magnet rings. A flux return path (,) provides a low flux resistant path from adjacent the Rose ring at one side of the imaging volume remotely around the imaging volume to a position adjacent the Rose ring at the other side of the imaging volume.