Magnetic field control apparatus
US5134374A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1990 |
| Grant date | Jul 28, 1992 |
| Priority date | — |
| Expiry date | Jul 18, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/0278
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic field control apparatus for establishing a uniform field of flux for use in magnetic resonance imaging has a pair of opposed magnetic poles mounted on end plates of variable thickness. A pair of substantially flat parallel pole faces are attached to the facing surfaces of the magnetic poles. The end plates are supported by connecting members. In addition, there is included a plurality of segments movably mounted to the periphery of the pole face for adjusting the density of the magnetic field. The top and bottom end plates may have substantially identical concave portions on the opposite outside surfaces thereof. The magnetic poles and pole faces are preferably in the shape of thin, flat, circular plates. In one embodiment, there is included one or more inner segmented concentric rings for further adjustably controlling the homogeneity of the uniform magnetic flux in the air gap between the opposing pole faces into which a patient can be inserted for magnetic resonance imaging. In another embodiment, the end plates are shaped so that the aggregate cross-sectional area taken in any plane perpendicular to the direction of the return flow of flux is substantially constant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.