US4862086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for generating magnetic fields utilized for magnetic resonance imaging apparatus
Assignee: Toshiba Corp
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Filing: 1988-04-21
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Granted: 1989-08-29
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Expires: 2008-04-21
Abstract
Abstract In an MRI apparatus, a static magnetic field is generated by a pair of magnets facing each other within a spacing. An axis direction of a subject inserted within the spacing is orthogonal to that of the static magnetic field. Gradient magnetic fields with X, Y and Z direction are generated by two pairs of plane coils, two pairs of plane coils, and a pair of plane coils, respectively, arranged between a pair of magnets. The plane coils for generated the gradient magnetic field in X direction is the same form as the plane coils for generating the gradient magnetic field in Z direction. By such an arrangement, gradient magnetic fields generated within the spacing have enough magnitude and linearity to obtain magnetic resonance signals. It is also enough spacing to insert a subject.
Inventors
- 👤 Tomohisa Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:52
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/385; G01R33/3806; G01R33/383
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
194 words
A system for generating magnetic fields utilized for magnetic resonance imaging apparatus, the system comprising: magnetic field generating means for generating a static magnetic field relative to a subject positioned within a space by arranging a pair of magnets facing each other; first coil means, including at least one pair of first plane coils facing each other between the pair of magnets, for generating a first gradient magnetic field within the space, each said first plane coil having at least one circular concentric turn; second coil means, including at least one pair of second plane coils facing each other between the pair of magnets, for generating a second gradient magnetic field within the space, each said second plane coil having at least one turn; and third coil means, including at least one pair of third plane coils facing each other between the pair of magnets, for generating a third gradient magnetic field within the space, each said third plane coil having at least one turn; wherein each of said second plane coil and third plane coil includes at least one straight portion corresponding to a chord and a return portion corresponding to an arc.
Claim 2
Independent Claim
194 words
A system for generating magnetic fields utilized for magnetic resonance imaging apparatus, the system comprising: magnetic field generating means for generating a static magnetic field relative to a subject positioned within a space by arranging a pair of magnets facing each other; first coil means, including at least one pair of first plane coils facing each other between the pair of magnets, for generating a first gradient magnetic field within the space, each said first plane coil having at least one circular concentric turn; second coil means, including at least one pair of second plane coils facing each other between the pair of magnets, for generating a second gradient magnetic field within the space, each said second plane coil having at least one turn; and third coil means, including at least one pair of third plane coils facing each other between the pair of magnets, for generating a third gradient magnetic field within the space, each said third plane coil having at least one turn; wherein each of said second plane coil and third plane coil includes at least one straight portion corresponding to a chord and a return portion corresponding to an arc.
Claim 3
Independent Claim
211 words
A system for generating magnetic fields utilized for magnetic resonance imaging apparatus, the system comprising: magnetic field generating means for generating a static magnetic field relative to a subject positioned within a space by arranging at least one static field coil outside the space, the static field coil being ring-shaped; first coil means, including at least one pair of first plane coils facing each other inside said at least one static field coil, for generating a first gradient magnetic field within the space, each of said first plane coil having at least one circular concentric turn; second coil means, including at least one pair of second plane coils facing each other inside said at least one static field coil, for generating a second gradient magnetic field within the space, each said second plane coil having at least one turn; and third coil means, including at least one pair of third plane coils facing each other inside said at least one static field coil, for generating a third gradient magnetic field within the space, each said third plane coil having at least one turn; wherein the second plane coil and the third plane coil include at least one straight portion corresponding to a chord and a return portion corresponding to an arc.
Claim 4
Independent Claim
211 words
A system for generating magnetic fields utilized for magnetic resonance imaging apparatus, the system comprising: magnetic field generating means for generating a static magnetic field relative to a subject positioned within a space by arranging at least one static field coil outside the space, the static field coil being ring-shaped; first coil means, including at least one pair of first plane coils facing each other inside said at least one static field coil, for generating a first gradient magnetic field within the space, each of said first plane coil having at least one circular concentric turn; second coil means, including at least one pair of second plane coils facing each other inside said at least one static field coil, for generating a second gradient magnetic field within the space, each said second plane coil having at least one turn; and third coil means, including at least one pair of third plane coils facing each other inside said at least one static field coil, for generating a third gradient magnetic field within the space, each said third plane coil having at least one turn; wherein the second plane coil and the third plane coil include at least one straight portion corresponding to a chord and a return portion corresponding to an arc.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |