US4996481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic resonance RF probe with electromagnetically isolated transmitter and receiver coils
Assignee: Washington University in St. Louis
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Filing: 1989-08-07
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Granted: 1991-02-26
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Expires: 2009-08-07
Abstract
Abstract An RF probe for use in magnetic resonance applications includes a transmitter coil for transmitting RF energy to excite a specimen and a receiver coil for sensing the RF energy absorbed or emitted by the specimen wherein the receiver coil is electrically decoupled from the transmitter coil through the geometrical shape and positioning of the receiver coil with respect to the transmitter coil. Both the transmitter and receiver coils are used to produce well defined RF magnetic fields. The technique includes the concept of physically locating multiple elements of either a transmitter or receiver coil such that the net current induced in the receiver coil is equal to zero. This technique is achieved in a frequency independent manner without orthogonally aligning the receiver coil with the transmitter coil, the coils being suitable for co-axial alignment as well as other alignments, much akin to prior art probes and thus readily adaptable to exisiting devices and protocols.
Inventors
- 👤 Joseph J. H. Ackerman
- 👤 Wei Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:11
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3642; G01R33/3657; G01R33/34; G01R33/341; G01R33/3621
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
86 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receive coil mounted non-orthogonally thereto, each of said coils having a near field radiation pattern of a well defined RF magnetic field, and said coils having a specific geometric orientation such that no significant coupling occurs therebetween as the coils radiate in each other's field and in the presence of said sample.
Claim 2
Dependent Claim
86 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receive coil mounted non-orthogonally thereto, each of said coils having a near field radiation pattern of a well defined RF magnetic field, and said coils having a specific geometric orientation such that no significant coupling occurs therebetween as the coils radiate in each other's field and in the presence of said sample.
Claim 3
Dependent Claim
17 words
The probe of claim 1 wherein one of said coils is comprised of at least two elements.
Claim 4
Dependent Claim
31 words
The probe of claim 2 wherein the receive is comprised of at least two elements and the net current induced in said two elements by the transmitter coil is substantially zero.
Claim 5
Dependent Claim
18 words
The probe of claim 3 wherein the said two elements are arranged substantially symmetrically about said transmitter coil.
Claim 6
Dependent Claim
16 words
The probe of claim 4 wherein said elements are substantially the same geometric size and shape.
Claim 7
Dependent Claim
26 words
The probe of claim 5 wherein said receiver coil is formed from a single length of conductor, and said elements are wound therefrom in opposite directions.
Claim 8
Dependent Claim
14 words
The probe of claim 6 wherein said receiver coil and transmitter coil are co-axial.
Claim 9
Dependent Claim
27 words
The probe of claim 1 further comprising means to adjust the relative spacing between the transmitter coil and the receiver coil to thereby tune the coupling therebetween.
Claim 10
Dependent Claim
31 words
The probe of claim 7 wherein the transmitter coil is comprised of a single loop of conductor and the receiver coil elements are each comprised of a single loop of conductor.
Claim 11
Dependent Claim
14 words
The probe of claim 9 wherein each of said loops is substantially a circle.
Claim 12
Dependent Claim
31 words
The probe of claim 2 wherein the transmitter coil is comprised of at least two elements and the current induced by said two elements in the receiver coil is substantially zero.
Claim 13
Dependent Claim
21 words
The probe of claim 1 further comprising means for tuning the probe to adjust the amount of coupling between the coils.
Claim 14
Dependent Claim
22 words
The probe of claim 12 wherein the probe tuning means comprises means for shifting one coil with respect to the other coil.
Claim 15
Dependent Claim
60 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil of generally circular shape and a receiver coil consisting of a pair of oppositely wound, generally circular coil elements, said receiver coil elements being symmetrically disposed about the transmitter coil so that RF energy transmitted from the transmitter coil does not induce substantially any significant current in the receiver coil.
Claim 16
Dependent Claim
60 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil of generally circular shape and a receiver coil consisting of a pair of oppositely wound, generally circular coil elements, said receiver coil elements being symmetrically disposed about the transmitter coil so that RF energy transmitted from the transmitter coil does not induce substantially any significant current in the receiver coil.
Claim 17
Dependent Claim
27 words
The probe of claim 14 further comprising means for tuning the probe to adjust the amount of current induced in said receiver coil by the transmitter coil.
Claim 18
Dependent Claim
26 words
The probe of claim 15 wherein said probe tuner means comprises means for adjusting the relative position of one coil with respect to the other coil.
Claim 19
Dependent Claim
70 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil consisting of a pair of oppositely wound coil elements, said coil elements being spaced apart from each other, and a receiver coil consisting of a single element, said receiver coil being positioned in a symmetrical location between and non-orthogonally to said transmitter coil elements so that substantially no significant current is induced by the transmitter coil in the receiver coil.
Claim 20
Dependent Claim
70 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil consisting of a pair of oppositely wound coil elements, said coil elements being spaced apart from each other, and a receiver coil consisting of a single element, said receiver coil being positioned in a symmetrical location between and non-orthogonally to said transmitter coil elements so that substantially no significant current is induced by the transmitter coil in the receiver coil.
Claim 21
Dependent Claim
97 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receiver coil mounted non-orthogonally thereto, each of said coils having a near field radiation pattern of a well defined RF magnetic field, said coils having a specific geometric orientation such that substantially no significant current is induced in one of said coils by the other of said coils as the coils radiate in each other's field and in the presence of said sample.
Claim 22
Dependent Claim
97 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receiver coil mounted non-orthogonally thereto, each of said coils having a near field radiation pattern of a well defined RF magnetic field, said coils having a specific geometric orientation such that substantially no significant current is induced in one of said coils by the other of said coils as the coils radiate in each other's field and in the presence of said sample.
Claim 23
Dependent Claim
14 words
The probe of claim 18 wherein one of said coils has multiple radiating elements.
Claim 24
Dependent Claim
17 words
The probe of claim 19 wherein said multiple radiating elements are symmetrically oriented about the other coil.
Claim 25
Dependent Claim
20 words
The probe of claim 20 wherein at least some of said elements are oppositely wound from others of said elements.
Claim 26
Dependent Claim
18 words
The probe of claim 21 wherein each of said coils are wound with a single loop of conductor.
Claim 27
Dependent Claim
27 words
The probe of claim 18 further comprising means for tuning the probe to adjust the amount of current induced in said receiver coil by the transmitter coil.
Claim 28
Dependent Claim
26 words
The probe of claim 23 wherein said probe tuner means comprises means for adjusting the relative position of one coil with respect to the other coil.
Claim 29
Dependent Claim
91 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receiver coil mounted non-orthogonally thereto, each of said coils having near field radiation pattern of a well defined RF magnetic field, said receiver coil comprising two elements, each of said elements being electrically symmetric so that no significant coupling occurs between said coils as they radiate in each other's fields and in the presence of the sample.
Claim 30
Dependent Claim
91 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receiver coil mounted non-orthogonally thereto, each of said coils having near field radiation pattern of a well defined RF magnetic field, said receiver coil comprising two elements, each of said elements being electrically symmetric so that no significant coupling occurs between said coils as they radiate in each other's fields and in the presence of the sample.
Claim 31
Dependent Claim
112 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receiver coils mounted non-orthogonally thereto, each of said coils having a near field radiation pattern of a well defined RF magnetic field, said receiver coil comprising two elements, one of said elements having a greater inductance than the other of said elements, so that no significant coupling occurs between said coils with the transmitter coil positioned closer to the element of lesser inductance as the coils radiate in each other's field and in the presence of the sample.
Claim 32
Dependent Claim
112 words
A probe for transmitting RF energy in an externally generated magnetic field and sensing a magnetic field induced in a sample by said transmitted RF energy, said probe comprising a transmitter coil and a receiver coils mounted non-orthogonally thereto, each of said coils having a near field radiation pattern of a well defined RF magnetic field, said receiver coil comprising two elements, one of said elements having a greater inductance than the other of said elements, so that no significant coupling occurs between said coils with the transmitter coil positioned closer to the element of lesser inductance as the coils radiate in each other's field and in the presence of the sample.
Claim 33
Dependent Claim
26 words
The probe of claim 26 wherein one of said receiver coil elements has a greater number of loops than the other of said receiver coil elements.
Claim 34
Dependent Claim
25 words
The probe of claim 26 wherein one of said receiver coil elements is a loop of larger diameter than the other of said receiver elements.
Claim 35
Dependent Claim
85 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil of generally circular shape and a receiver coil of oppositely wound, generally circular coil elements, one of said receiver coil elements comprising a single loop of conductor and the other of said receiver coil elements comprising a plurality of loops of conductor, the transmitter coil being positioned closer to the single loop receiver coil element so that RF energy transmitted from the transmitter coil does not induce substantially any significant current in the receiver coil.
Claim 36
Dependent Claim
85 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil of generally circular shape and a receiver coil of oppositely wound, generally circular coil elements, one of said receiver coil elements comprising a single loop of conductor and the other of said receiver coil elements comprising a plurality of loops of conductor, the transmitter coil being positioned closer to the single loop receiver coil element so that RF energy transmitted from the transmitter coil does not induce substantially any significant current in the receiver coil.
Claim 37
Dependent Claim
74 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil of generally circular shape and a receiver coil of oppositely wound, generally circular coil elements, one of said receiver coil elements having a greater diameter than the other of said receiver coil elements, the transmitter coil being positioned closer to the smaller coil element so that RF energy transmitted from the transmitter coil does not induce substantially any significant current in the receiver coil.
Claim 38
Dependent Claim
74 words
A multiple antenna surface-coil NMR probe comprising a transmitter coil of generally circular shape and a receiver coil of oppositely wound, generally circular coil elements, one of said receiver coil elements having a greater diameter than the other of said receiver coil elements, the transmitter coil being positioned closer to the smaller coil element so that RF energy transmitted from the transmitter coil does not induce substantially any significant current in the receiver coil.
Claim 39
Dependent Claim
27 words
The probe of claim 25 further comprising means for tuning the probe to adjust the amount of current induced in said receiver coil by the transmitter coil.
Claim 40
Dependent Claim
26 words
The probe of claim 31 wherein said probe tuner means comprises means for adjusting the relative position of one coil with respect to the other coil.
References Cited (Backward Citations)
US2220070A
Cited
US2451596A
Cited
US3826973A
Cited
US4093910A
Cited
US4620155A
Cited
US4636730A
Cited
US4887039A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |