Patent US5840087A successfully refreshed from Google Patents.
Patent US5777474A successfully refreshed from Google Patents.
US5777474A
Expired / Lapsed
US
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Radio-frequency coil and method for resonance imaging/analysis
Assignee: Advanced Imaging Research Inc
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Filing: 1996-11-08
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Granted: 1998-07-07
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Expires: 2016-11-08
Abstract
Abstract An RF coil which includes an RF coil primary, an RF coil secondary, and coupling impedances that connect the two at several points along the coil peripheries. The coupling impedances are primarily reactive, and may be fixed or variable, depending on the purpose of use.
Inventors
- 👤 Ravi Srinivasan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:07
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3628; G01R33/34; G01R33/34046; G01R33/42; G01R33/422; G01R33/341; G01R33/3635
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
147 words
A radio-frequency (RF) coil for resonance imaging/analysis, comprising: an RF coil primary sensitive to RF signals produced during resonance imaging/analysis, the RF coil primary having a usable field of view; an RF coil secondary positioned physically adjacent the RF coil primary at a predetermined distance apart and mutually coupled to the RF coil primary at a frequency of the RF signals; and coupling impedances electrically connecting the RF coil primary to the RF coil secondary to regulate an amount of current induced in the RF coil secondary at the frequency to provide screening relative to the RF coil primary, and to form current loops between the RF coil primary and the RF coil secondary serving to redirect at least a substantial portion of flux back into the useable field of view which would otherwise impinge on the RF coil secondary in the absence of the coupling impedances.
Claim 2
Dependent Claim
147 words
A radio-frequency (RF) coil for resonance imaging/analysis, comprising: an RF coil primary sensitive to RF signals produced during resonance imaging/analysis, the RF coil primary having a usable field of view; an RF coil secondary positioned physically adjacent the RF coil primary at a predetermined distance apart and mutually coupled to the RF coil primary at a frequency of the RF signals; and coupling impedances electrically connecting the RF coil primary to the RF coil secondary to regulate an amount of current induced in the RF coil secondary at the frequency to provide screening relative to the RF coil primary, and to form current loops between the RF coil primary and the RF coil secondary serving to redirect at least a substantial portion of flux back into the useable field of view which would otherwise impinge on the RF coil secondary in the absence of the coupling impedances.
Claim 3
Dependent Claim
20 words
The RF coil of claim 1, wherein the RF primary and secondary coils each comprise a planar loop type coil.
Claim 4
Dependent Claim
24 words
The RF coil of claim 2, wherein the loop type coils of the RF primary and secondary coils are respectively oriented in parallel planes.
Claim 5
Dependent Claim
13 words
The RF coil of claim 3, wherein the loop type coils are rectangular.
Claim 6
Dependent Claim
13 words
The RF coil of claim 3, wherein the loop type coils are circular.
Claim 7
Dependent Claim
14 words
The RF coil of claim 3, wherein the RF coil is a quadrature coil.
Claim 8
Dependent Claim
13 words
The RF coil of claim 1, wherein the RF coil secondary is resonant.
Claim 9
Dependent Claim
42 words
The RF coil of claim 1, wherein the RF coil primary comprises a planar coil having an axis substantially perpendicular to the plane thereof, and a magnetic B field profile of the RF coil at the frequency is asymmetric along the axis.
Claim 10
Dependent Claim
19 words
The RF coil of claim 1, wherein the RF primary and secondary coils each comprise a volume type coil.
Claim 11
Dependent Claim
16 words
The RF coil of claim 9, wherein the volume type coils are each birdcage type coils.
Claim 12
Dependent Claim
43 words
A resonance imaging/analysis system, comprising; an RF coil as recited in claim 1; and means for processing RF signals which are at least one of received from the RF coil and transmitted from the RF coil in order to obtain a resonance image/analysis.
Claim 13
Dependent Claim
85 words
A multiple tuned RF coil, comprising: an RF coil primary having a usable field of view; an RF coil secondary physically adjacent the RF coil primary and mutually coupled to the RF coil primary; and coupling impedances electrically connecting the RF coil primary to the RF coil secondary to regulate an amount of current flowing between the RF coil primary and the RF coil secondary, wherein the RF coil is tuned to resonate at a plurality of different RF signal frequencies produced during resonance imaging/analysis.
Claim 14
Dependent Claim
85 words
A multiple tuned RF coil, comprising: an RF coil primary having a usable field of view; an RF coil secondary physically adjacent the RF coil primary and mutually coupled to the RF coil primary; and coupling impedances electrically connecting the RF coil primary to the RF coil secondary to regulate an amount of current flowing between the RF coil primary and the RF coil secondary, wherein the RF coil is tuned to resonate at a plurality of different RF signal frequencies produced during resonance imaging/analysis.
Claim 15
Dependent Claim
28 words
The RF coil of claim 162 wherein a B field profile in the usable field of view is substantially similar at the plurality of different RF signal frequencies.
Claim 16
Dependent Claim
44 words
The RF coil of claim 12, wherein the RF coil primary represents substantially an RF short circuit at one of the plurality of different frequencies and the RF coil secondary represents substantially an RF open circuit at another of the plurality of different frequencies.
Claim 17
Dependent Claim
13 words
The RF coil of claim 12, wherein the RF coil secondary is non-resonant.
Claim 18
Dependent Claim
16 words
The RF coil of claim 12, wherein the RF coil secondary functions as an RF screen.
Claim 19
Dependent Claim
138 words
A radio-frequency (RF) coil for resonance imaging/analysis, comprising: an RF coil primary sensitive to RF signals produced during resonance imaging/analysis, the RF coil primary having a usable field of view; an RF coil secondary positioned physically adjacent the RF coil primary at a predetermined distance apart and mutually coupled to the RF coil primary at a frequency of the RF signals; and coupling impedances electrically connecting the RF coil primary to the RF coil secondary to regulate an amount of current induced in the RF coil secondary at the frequency, and to form current loops between the RF coil primary and the RF coil secondary serving to redirect at least a substantial portion of flux back into the useable field of view which would otherwise impinge on the RF coil secondary in the absence of the coupling impedances.
Claim 20
Dependent Claim
138 words
A radio-frequency (RF) coil for resonance imaging/analysis, comprising: an RF coil primary sensitive to RF signals produced during resonance imaging/analysis, the RF coil primary having a usable field of view; an RF coil secondary positioned physically adjacent the RF coil primary at a predetermined distance apart and mutually coupled to the RF coil primary at a frequency of the RF signals; and coupling impedances electrically connecting the RF coil primary to the RF coil secondary to regulate an amount of current induced in the RF coil secondary at the frequency, and to form current loops between the RF coil primary and the RF coil secondary serving to redirect at least a substantial portion of flux back into the useable field of view which would otherwise impinge on the RF coil secondary in the absence of the coupling impedances.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-07-06 | 2002-01-05 | 2002-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-07-06 | 2006-01-05 | 2006-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-07-06 | 2010-01-05 | 2010-07-07 | $7700.00 | Window Closed / Lapsed |