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:
Dec. 01, 1992
Filed:
Jun. 29, 1990
Gary H Glover, Menlo Park, CA (US);
Erika Schneider, New Berlin, WI (US);
General Electric Company, Milwaukee, WI (US);
Abstract
Determination of the shimming fields for a polarizing NMR magnet is performed by acquiring two NMR images with evolution times differing by .tau.. A pixel by pixel division of the images yields a third image whose phase is proportional to magnetic field inhomogeneity. Several such inhomogeneity images are acquired within a cylindrical volume and the data of the images is fit according to a set of polynomials approximating the fields of the magnet shim coils. The coefficients of this fitting procedure are used to set the current level in the corresponding shim coils. The interaction between correction fields is accommodated by an empirically derived correction matrix. This procedure may be repeated to provide more accurate shimming.