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. 01, 1997
Filed:
Feb. 22, 1996
John Maurice Bird, Oxfordshire Ox, GB;
Alan George Armstrong, Oxon Ox, GB;
Elscint Ltd., Haifa, IL;
Abstract
This invention is concerned with actively shielded magnetic resonance (MR) devices and more particularly with protecting such systems in the event of a quench by preventing changes in the stray field outside the magnetic devices. The invention includes dividing the system's coils into groups each comprised of inner and outer coils and arranged so that the net dipole moment, and the contribution to stray field from each group is always close to zero. Each group is connected in parallel to a protective unit, for example a resistor, so that the excess current can flow through the protective unit in the event of a quench; thus avoiding the burnout of the system's coils.