US5003266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Passively improving magnetic field homogeneity
Assignee: General Electric Co
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Filing: 1989-07-12
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Granted: 1991-03-26
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Expires: 2009-07-12
Abstract
Abstract Shim holding independently accessible open cavities are attached to the magnet bore. The holding independently accessible open cavities are arranged in rows and columns to provide readily identifiable locations. The shim holding indpendently accessible open cavities increase the effeciency of shimming to improve the homogeneity of magnets in magnetic resonance systems.
Inventors
- 👤 Alex Palkovich
- 👤 Ratson Morad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:26
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/387; G01R33/3873
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
96 words
A system for passively improving homogeneity of the main magnet in magnetic resonance systems by shimming the main static magnetic field, said main magnet including a bore therein for receiving patients in the main magnet, said shimming being done responsive to computerized indications of shim locations, said system comprising: shims, tray means attached to the bore of said magnet, said tray means including means for holding said shims in independently accessible locations in accordance with the computerized indications of the shim locations, and said tray means comprising location indications providing readily identifiable locations for the shims.
Claim 2
Independent Claim
96 words
A system for passively improving homogeneity of the main magnet in magnetic resonance systems by shimming the main static magnetic field, said main magnet including a bore therein for receiving patients in the main magnet, said shimming being done responsive to computerized indications of shim locations, said system comprising: shims, tray means attached to the bore of said magnet, said tray means including means for holding said shims in independently accessible locations in accordance with the computerized indications of the shim locations, and said tray means comprising location indications providing readily identifiable locations for the shims.
Claim 3
Dependent Claim
20 words
The system of claim 1, wherein said tray means comprises plurality of independently accessible open cavities for receiving said shims.
Claim 4
Dependent Claim
33 words
The system of claim 2, wherein the surface dimensions of the shims are slightly smaller than the opening dimensions of said independently accessible open cavities whereby said shims press fit into said cavities.
Claim 5
Dependent Claim
31 words
The system of claim 2, wherein thickness dimension of said shims is less than the depth of said cavities whereby a plurality of shims fit into each independently accessible open cavity.
Claim 6
Dependent Claim
18 words
The system of claim 3 wherein glue means are provided for affixing the shims to said holding means.
Claim 7
Dependent Claim
20 words
The system of claim 5 wherein said cavities are shaped to enhance the removal of said shims from said cavities.
Claim 8
Dependent Claim
24 words
The system of claim 2, wherein said shim trays have said cavities arranged in rows and columns, with each row and column separately identified.
Claim 9
Dependent Claim
22 words
The system of claim 7 wherein said rows and columns are unevenly spaced to provide effective shimming even to the tenth harmonic.
Claim 10
Dependent Claim
22 words
The system of claim 8 wherein means are provided to attach said trays to each other forming a cylinder within said bore.
Claim 11
Independent Claim
22 words
The system as in any one of claims 7-9 wherein said shim trays are glued to the bore of said main magnet.
Claim 12
Dependent Claim
29 words
The system of claim 2 wherein the thickness dimension of said shims in less than the depth of said pockets whereby a plurality of shims fit into each pocket.
Claim 13
Dependent Claim
18 words
The system of claim 1 wherein glue means are provided for affixing the shims to said holding means.
Claim 14
Dependent Claim
18 words
The system of claim 2 wherein glue means are provided for affixing the shims to said holding means.
Claim 15
Dependent Claim
20 words
The system of claim 2 wherein said pockets are shaped to enhance the removal of said shims from said pockets.
Claim 16
Dependent Claim
20 words
The system of claim 3 wherein said pockets are shaped to enhance the removal of said shims from said pockets.
Claim 17
Dependent Claim
20 words
The system of claim 4 wherein said pockets are shaped to enhance the removal of said shims from said pockets.
Claim 18
Dependent Claim
33 words
The system of claim 2 wherein said holding means comprises a plurality of shim trays, said shim trays having said pockets arranged in rows and columns with each row and column separately identified.
Claim 19
Dependent Claim
33 words
The system of claim 3 wherein said holding means comprises a plurality of shim trays, said shim trays having said pockets arranged in rows and columns with each row and column separately identified.
Claim 20
Dependent Claim
33 words
The system of claim 4 wherein said holding means comprises a plurality of shim trays, said shim trays having said pockets arranged in rows and columns with each row and column separately identified.
Claim 21
Dependent Claim
33 words
The system of claim 5 wherein said holding means comprises a plurality of shim trays, said shim trays having said pockets arranged in rows and columns with each row and column separately identified.
References Cited (Backward Citations)
US4743853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-25 | 1994-09-24 | 1995-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-25 | 1998-09-24 | 1999-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-25 | 2002-09-24 | 2003-03-26 | $7700.00 | Window Closed / Lapsed |