Patent US5243289A successfully refreshed from Google Patents.
US5243289A
Expired / Lapsed
US
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Multiply-tuned probe for magnetic resonance imaging or spectroscopy
Assignee: TRUSTEES OF UNIVERSITY OF PENNSYLVANIA A NON-PROFIT CORP OF PENNSYLVANIA
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Filing: 1991-08-09
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Granted: 1993-09-07
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Expires: 2011-08-09
Abstract
Abstract A multiply-tuned probe for magnetic resonance imaging or spectroscopy in which a driving inductor is separately coupled to two or more trap inductors. The impedance match at each frequency is adjusted independently of the impedance match at the other frequencies and independent of the tuning by using a novel coil geometry with no overcoupling. In a preferred embodiment, a triple-tuned probe has a first inductor L1 disposed in a first plane and tuned to a first resonant frequency and a second inductor L2 disposed in a second plane parallel to the first plane and tuned to a second resonant frequency. A driving and receiving primary inductor Lp is disposed in a third plane parallel to the first and second planes and placed with respect to the first and second inductors L1 and L2 such that mutual inductance between L1 and Lp in between L2 and Lp is adjustable in accordance with the positions of the inductors L1, L2 and Lp. A sample surface inductor Ls tuned to a third resonant frequency provides the third frequency. Mutual inductance between L1 and Lp in between L2 and Lp is changed by repositioning the inductors L1, L2 and Lp to vary the amount of overlap between the cross-sections of the primary inductor Lp and the circular coils L1, L2 and the distances between inductors L1 and Lp and between inductors L2 and Lp. Since each inductive coupling adds another variable to the probe circuit, more and easier ways are provided for adjusting the tuning and impedance matching.
Inventors
- 👤 Haywood Blum
- 👤 Matthew D. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:03
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3628; G01R33/3635
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
193 words
A multi-frequency tuned probe, comprising: a first substantially planar inductor L1 disposed in a first plane; first means for tuning said first planar inductor L1 to a first resonant frequency; a second substantially planar inductor L2 disposed in a second plane, parallel to said first plane; second means for tuning said second planar inductor L2 to a second resonant frequency; and a substantially planar driving and receiving primary inductor Lp disposed in a third plane which is parallel to said first and second planes, said primary inductor Lp being adapted to transmit and receive RF pulses and signals and being disposed with respect to said first and second inductors L1 and L2 such that mutual inductance between L1 and Lp and between L2 and Lp occurs when a current is applied to L1, L2 and Lp, said mutual inductance being adjustable in accordance with the respective distances between each of said inductors L1, L2 and Lp in a direction perpendicular to said first, second and third planes and in accordance with the amount of overlap among said inductors L1, L2 and Lp in coordinate directions parallel to said first, second and third planes.
Claim 2
Dependent Claim
193 words
A multi-frequency tuned probe, comprising: a first substantially planar inductor L1 disposed in a first plane; first means for tuning said first planar inductor L1 to a first resonant frequency; a second substantially planar inductor L2 disposed in a second plane, parallel to said first plane; second means for tuning said second planar inductor L2 to a second resonant frequency; and a substantially planar driving and receiving primary inductor Lp disposed in a third plane which is parallel to said first and second planes, said primary inductor Lp being adapted to transmit and receive RF pulses and signals and being disposed with respect to said first and second inductors L1 and L2 such that mutual inductance between L1 and Lp and between L2 and Lp occurs when a current is applied to L1, L2 and Lp, said mutual inductance being adjustable in accordance with the respective distances between each of said inductors L1, L2 and Lp in a direction perpendicular to said first, second and third planes and in accordance with the amount of overlap among said inductors L1, L2 and Lp in coordinate directions parallel to said first, second and third planes.
Claim 3
Dependent Claim
38 words
A multi-frequency tuned probe as in claim 1, further comprising a sample surface inductor Ls for transmitting and receiving RF pulses and signals and third means for tuning said sample surface inductor Ls to a third resonant frequency.
Claim 4
Dependent Claim
22 words
A multi-frequency tuned probe as in claim 2, wherein said first inductor L1 and second inductor L2 comprise coaxially disposed circular coils.
Claim 5
Dependent Claim
63 words
A multi-frequency tuned probe as in claim 3, wherein said primary inductor Lp comprises a primary circular coil disposed between said first inductor L1 and second inductor L2 such that at least a portion of a cross-section of said primary circular coil overlaps a cross-section of said coaxially disposed circular coils in said coordinate directions parallel to said first, second and third planes.
Claim 6
Dependent Claim
58 words
A multi-frequency tuned probe as in claim 4, wherein said mutual inductance between L1 and Lp and between L2 and Lp is changed in accordance with the amount of overlap between the cross-sections of said primary circular coil and said coaxially disposed circular coils and the distances between inductors L1 and Lp and between inductors L2 and Lp.
Claim 7
Dependent Claim
21 words
A multi-frequency tuned probe as in claim 4, wherein said primary circular coil is coaxial with said coaxially disposed circular coils.
Claim 8
Dependent Claim
100 words
A multi-frequency tuned probe as in claim 2, wherein said first tuning means comprises a first variable capacitance C1 electrically connected in parallel with said first inductor L1 so as to form a first tank circuit which is tuned to said first resonant frequency by adjusting a capacitance of said first variable capacitance C1 and said second tuning mean comprises a second variable capacitance C2 electrically connected in parallel with said second inductor L2 so as to form a second tank circuit which is tuned to said second resonant frequency by adjusting a capacitance of said second variable capacitance C2.
Claim 9
Dependent Claim
54 words
A multi-frequency tuned probe as in claim 7, further comprising a sample variable capacitance Cs electrically connected in series with said sample surface inductor Ls and said first and second tank circuits, said sample surface inductor Ls being tuned to said third resonant frequency by adjusting a capacitance of said sample variable capacitance Cs.
Claim 10
Dependent Claim
71 words
A multi-frequency tuned probe as in claim 8, further comprising a transmission line connected to said primary inductor Lp, wherein said first inductor L1, said second inductor L2 and said sample surface inductor Ls are respectively impedance matched to said transmission line at said first, second and third resonant frequencies simultaneously by adjusting capacitances of said first variable capacitance C1, said second variable capacitance C2, and said sample variable capacitance Cs.
Claim 11
Dependent Claim
98 words
A multi-frequency tuned probe, comprising: at least two trap circuits disposed concentrically about a common axis; means for tuning each trap circuit to a desired resonant frequency; and a driving and receiving primary inductor Lp substantially concentrically disposed with respect to said at least two trap circuits about said common axis such that mutual inductance between Lp and each of said trap circuits occurs when a current is applied to said trap circuits and Lp, said mutual inductance being adjustable in accordance with the respective distances between Lp and each of said trip circuits along said common axis.
Claim 12
Dependent Claim
98 words
A multi-frequency tuned probe, comprising: at least two trap circuits disposed concentrically about a common axis; means for tuning each trap circuit to a desired resonant frequency; and a driving and receiving primary inductor Lp substantially concentrically disposed with respect to said at least two trap circuits about said common axis such that mutual inductance between Lp and each of said trap circuits occurs when a current is applied to said trap circuits and Lp, said mutual inductance being adjustable in accordance with the respective distances between Lp and each of said trip circuits along said common axis.
References Cited (Backward Citations)
US4742304A
Cited
US4792759A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-09-06 | 1997-03-08 | 1997-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-06 | 2001-03-08 | 2001-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-06 | 2005-03-08 | 2005-09-07 | $7700.00 | Window Closed / Lapsed |