US4616181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear magnetic resonance tomography apparatus
Assignee: US Philips Corp
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Filing: 1983-10-06
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Granted: 1986-10-07
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Expires: 2003-10-06
Abstract
Abstract The transmitter/measurement coil of a nuclear magnetic resonance tomography apparatus for medical diagnosis in which comparatively high Larmor frequencies are used, is divided into a number of parallel-connected subcoils. The self resonance frequency of the coil can thus be made substantially higher than the Larmor frequency, with the result that the coil will have a suitably improved quality factor at higher frequencies, and measurements can be performed with an acceptable signal-to-noise ratio.
Inventors
- 👤 Rudolf Kemner
- 👤 Dirk Sinnema
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:44
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/34; G01R33/34046; G01R33/34069; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/844
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
161 words
In nuclear magnetic resonance tomography apparatus which comprises: first coil means for generating a primary magnetic field; second coil means for generating a pulsed RF magnetic field, said first and second coil means being disposed around a substantially cylindrical examination space for an object to be examined; and measurement means for detecting nuclear magnetic resonance signals which are generated in the object; the improvement wherein: the self-resonance frequency of the second coil means is substantially higher than the highest frequency component of the resonance signals which are to be detected; the second coil means comprises two saddle-shaped coils which are disposed on diametrically opposite sides of the examination space, each of said saddle-shaped coils comprising at least two sub-coils; each of the sub-coils comprises a winding; further comprising means which supply the sub-coils with pulsed radio frequency electric current; the windings of all the sub-coils being connected, in parallel, to the means which supply them with pulsed radio frequency electric current.
Claim 2
Dependent Claim
161 words
In nuclear magnetic resonance tomography apparatus which comprises: first coil means for generating a primary magnetic field; second coil means for generating a pulsed RF magnetic field, said first and second coil means being disposed around a substantially cylindrical examination space for an object to be examined; and measurement means for detecting nuclear magnetic resonance signals which are generated in the object; the improvement wherein: the self-resonance frequency of the second coil means is substantially higher than the highest frequency component of the resonance signals which are to be detected; the second coil means comprises two saddle-shaped coils which are disposed on diametrically opposite sides of the examination space, each of said saddle-shaped coils comprising at least two sub-coils; each of the sub-coils comprises a winding; further comprising means which supply the sub-coils with pulsed radio frequency electric current; the windings of all the sub-coils being connected, in parallel, to the means which supply them with pulsed radio frequency electric current.
Claim 3
Dependent Claim
33 words
The apparatus of claim 1 wherein, in each of the saddle-shaped coils, the sub-coils are separated from one another by planes which extend perpendicular to the axis of the substantially cylindrical examination space.
Claim 4
Dependent Claim
33 words
The apparatus of claim 1 wherein, in each of the saddle-shaped coils, the sub-coils are separated from one another by planes which extend perpendicular to the axis of the substantially cylindrical examination space.
Claim 5
Dependent Claim
31 words
A nuclear magnetic resonance tomography apparatus as claimed in any one of claims 3, 2, or 1 further comprising comb-shaped electrical screening elements disposed in openings between the two saddle-shaped coils.
Claim 6
Dependent Claim
27 words
A nuclear magnetic resonance tomography apparatus as claimed in any one of claims 3, 2 or 1, wherein the first coil means comprises a superconducting magnet coil.
Claim 7
Dependent Claim
36 words
The apparatus of claim 1 wherein each of the sub-coils comprises a winding and the windings of all of the sub-coils are connected, in parallel, to means which supply them with pulsed radio frequency electric current.
References Cited (Backward Citations)
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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) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |