US5325060A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coil circuits
Assignee: BTG International Ltd
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Filing: 1991-05-24
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Granted: 1994-06-28
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Expires: 2011-05-24
Abstract
Abstract A coil circuit comprising a multi-mode resonant gradient or RF coil circuits for imaging and spectroscopy in Nuclear Magnetic Resonance systems.
Inventors
- 👤 Peter Mansfield
- 👤 Ronald J. Coxon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:34
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3628; G01R33/3635; G01R33/38; G01R33/385; G01R33/3852
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
87 words
A multi-mode resonant coil circuit comprising: a magnetic gradient field coil designed to produce a desired magnetic field which changes in strength in a certain given direction, passive components which are effective to generate a square or trapezoidal output current waveform in said magnetic gradient field oil when supplied with an input current waveform comprising a series of weighted Fourier Harmonics, and connections between said passive components and said coil arranged so that a total current input to the components passes through the magnetic gradient field coil.
Claim 2
Dependent Claim
87 words
A multi-mode resonant coil circuit comprising: a magnetic gradient field coil designed to produce a desired magnetic field which changes in strength in a certain given direction, passive components which are effective to generate a square or trapezoidal output current waveform in said magnetic gradient field oil when supplied with an input current waveform comprising a series of weighted Fourier Harmonics, and connections between said passive components and said coil arranged so that a total current input to the components passes through the magnetic gradient field coil.
Claim 3
Dependent Claim
24 words
A multi-mode resonant coil circuit as claimed in claim 1 further comprising a voltage generator or current generator for supplying said input current waveform.
Claim 4
Dependent Claim
74 words
A multi-mode resonant coil circuit as claimed in claim 1 in which the passive components comprise a first arrangement including a plurality of capacitors, resistors and further coils, a second coil, in series with the first arrangement, the first arrangement including said plurality of capacitors, resistors and further coils connected in at least two parallel circuits, each parallel circuit comprising at least one capacitor and at least one of said further coils, in series.
Claim 5
Independent Claim
99 words
A method of generating a square wave or trapezoidal waveform for an NMR apparatus comprising the steps of: connecting a passive electrical circuit in series with one terminal of a gradient coil, connecting a source, which can be a current or voltage waveform source, across the coil and the passive electrical circuit, and energizing said source, in which said connecting step includes connecting the gradient coil in a way in which all of the current from said source passes through said gradient coil and in which the current or voltage waveform comprises a series of suitably weighted Fourier Harmonics.
Claim 6
Independent Claim
99 words
A method of generating a square wave or trapezoidal waveform for an NMR apparatus comprising the steps of: connecting a passive electrical circuit in series with one terminal of a gradient coil, connecting a source, which can be a current or voltage waveform source, across the coil and the passive electrical circuit, and energizing said source, in which said connecting step includes connecting the gradient coil in a way in which all of the current from said source passes through said gradient coil and in which the current or voltage waveform comprises a series of suitably weighted Fourier Harmonics.
Claim 7
Dependent Claim
47 words
A multi-mode resonant coil circuit as claimed in claim 1 wherein said passive components are arranged in the form of a ladder network or cascaded parallel circuit comprising a plurality of parallel resonant traps in series with periodically placed shunt capacitors forming rungs of the ladder network.
Claim 8
Dependent Claim
45 words
A multi-mode resonant coil circuit as claimed in claim 1 wherein said passive components are arranged in the form of a ladder network or cascaded parallel circuit comprising a plurality of series capacitors with periodically placed parallel resonant traps forming rungs of the ladder network.
Claim 9
Dependent Claim
44 words
A multi-mode resonant coil circuit as claimed in claim 1 wherein said passive components are arranged in the form of a ladder network or cascaded parallel circuit comprising a plurality of series coils with periodically placed shunt capacitors forming rungs of the ladder network.
Claim 10
Dependent Claim
44 words
A multi-mode resonant coil circuit as claimed in claim 1 wherein said passive components are arranged in the form of a ladder network or cascaded parallel circuit comprising a plurality of series capacitors with periodically placed shunt coils forming rungs of the ladder network.
Claim 11
Dependent Claim
22 words
A multi-mode resonant current as claimed in claim 1 in which the circuit is driven by at least one constant current amplifier.
Claim 12
Dependent Claim
21 words
A multi-mode resonant circuit according to claim 1 in which the circuit is driven by at least one constant voltage amplifier.
Claim 13
Dependent Claim
16 words
A coil as claimed in claim 8 in which the coil is driven by two amplifiers.
Claim 14
Dependent Claim
16 words
A coil as claimed in claim 9 in which the coil is driven by two amplifiers.
Claim 15
Dependent Claim
17 words
A coil as claimed in claim 11 in which one of the amplifiers is a d.c. amplifier.
References Cited (Backward Citations)
US4680545A
Cited
GB2184625A
Cited
US4742304A
Cited
US4862084A
Cited
US5168228A
Cited
US5162736A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |