US4398150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ironless high-homogenety magnet and its application to nuclear magnetic resonance imaging
Assignee: THOMSON-CGR 13
•
Filing: 1981-02-02
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Granted: 1983-08-09
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Expires: 2001-02-02
Abstract
Abstract The magnet essentially comprises at least three pairs of coaxial coils in order to increase the number of available parameters, to reduce the non-uniformity B d , to provide an examination volume with a double access consisting of a longitudinal access along the axis of revolution Oz and of a transverse access parallel to the plane of symmetry, to minimize the overall size as well as the dissipated electric power. The nine principal characteristic parameters of the coils are chosen so as to optimize the uniformity of the magnetic field within the examination volume.
Inventors
- 👤 Yves M. Barjhoux
- 👤 Herve Saint Jalmes
- 👤 Jacques R. Taquin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:49
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/3806
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
132 words
An ironless magnet having high field uniformity comprising an even number of electromagnetic coils of revolution which are symmetrical with respect to a plane of symmetry at right angles to their axis of revolution, each coil being defined by its characteristic parameters: its excitation current NI, its means radius R, the distance d between said coil and the plane of symmetry; said magnet comprises at least two pairs of coils for increasing the number of available parameters and reducing the non-uniformity B b of the magnetic field; said coils defining an examination volume with a double access consisting of a longitudinal access along the axis of revolution and of a transverse access parallel to the plane of symmetry, thereby reducing the overall size and also the dissipated electric power of said magnets.
Claim 2
Dependent Claim
132 words
An ironless magnet having high field uniformity comprising an even number of electromagnetic coils of revolution which are symmetrical with respect to a plane of symmetry at right angles to their axis of revolution, each coil being defined by its characteristic parameters: its excitation current NI, its means radius R, the distance d between said coil and the plane of symmetry; said magnet comprises at least two pairs of coils for increasing the number of available parameters and reducing the non-uniformity B b of the magnetic field; said coils defining an examination volume with a double access consisting of a longitudinal access along the axis of revolution and of a transverse access parallel to the plane of symmetry, thereby reducing the overall size and also the dissipated electric power of said magnets.
Claim 3
Dependent Claim
16 words
A magnet according to claim 1, wherein said magnet is constituted by three pairs of coils.
Claim 4
Dependent Claim
29 words
A magnet according to claim 2, wherein one of the pairs of coils is located within the interior of that pair of coils which is nearest the examination volume.
Claim 5
Dependent Claim
29 words
A magnet according to claim 1, wherein each coil is made up of main turns and adjustment turns which are employed for adjusting the uniformity of the magnetic field.
Claim 6
Dependent Claim
37 words
A magnet according to claim 1, wherein said magnet is employed in an examination system which utilizes nuclear magnetic resonance for producing the orienting magnetic field B o in which the body to be examined is placed.
Claim 7
Dependent Claim
124 words
An ironless magnet having high field uniformity and comprising an examination space for submitting a body to this field, comprising a set of electromagnetic coils for revolution which are symmetrically arranged in pairs with respect to a plane of symmetry at right angles to their axis of revolution, each coil being defined by its characteristic parameters: its excitation current NI, its mean radius R and its distance d to the plane of symmetry, wherein said magnet comprises at least three pairs of coils, said space having a double access one on one side and the other on the other of the plane of symmetry, and said space being delimited by opposite faces of the pair of coils the nearest from said plane of symmetry.
Claim 8
Dependent Claim
124 words
An ironless magnet having high field uniformity and comprising an examination space for submitting a body to this field, comprising a set of electromagnetic coils for revolution which are symmetrically arranged in pairs with respect to a plane of symmetry at right angles to their axis of revolution, each coil being defined by its characteristic parameters: its excitation current NI, its mean radius R and its distance d to the plane of symmetry, wherein said magnet comprises at least three pairs of coils, said space having a double access one on one side and the other on the other of the plane of symmetry, and said space being delimited by opposite faces of the pair of coils the nearest from said plane of symmetry.
References Cited (Backward Citations)
US2856579A
Cited
US3488561A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |