US4623844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
NMR inhomogeneity compensation system
Assignee: Individual
•
Filing: 1983-07-18
•
Granted: 1986-11-18
•
Expires: 2003-07-18
Abstract
Abstract The volume of interest is excited. An array of pickup coils with water cores provide an array of signals whose frequencies indicate the magnetic field distribution. These frequencies are estimated and used to produce controlled magnetic field inhomogeneities which substantially cancel the undesired inhomogeneities in the field. The control signals can be stored and updated with each subsequent excitation.
Inventors
- 👤 Albert Macovski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:52
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/387; G01R33/3875; G01R33/24; G01R33/389; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/844
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
48 words
In a method for correcting magnetic field inhomogeneities in an NMR system the steps of: measuring the degree of homogeneity by measuring the duration of a received NMR signal following an excitation; and generating magnetic fields which substantially cancel the inhomogeneities so as to maximize the measured homogeneity.
Claim 2
Dependent Claim
48 words
In a method for correcting magnetic field inhomogeneities in an NMR system the steps of: measuring the degree of homogeneity by measuring the duration of a received NMR signal following an excitation; and generating magnetic fields which substantially cancel the inhomogeneities so as to maximize the measured homogeneity.
Claim 3
Dependent Claim
46 words
Apparatus for correcting magnetic field inhomogeneities in an NMR system comprising: means for measuring the degree of homogeneity by measuring the duration of a received nmr signal following an excitation; and means for generating magnetic fields which substantially cancel the inhomogeneities and maximize the measured homogeneity.
Claim 4
Dependent Claim
46 words
Apparatus for correcting magnetic field inhomogeneities in an NMR system comprising: means for measuring the degree of homogeneity by measuring the duration of a received nmr signal following an excitation; and means for generating magnetic fields which substantially cancel the inhomogeneities and maximize the measured homogeneity.
Claim 5
Dependent Claim
25 words
Apparatus as described in claim 2 wherein the means for generating fields which substantially cancel the inhomogeneities includes the step of applying controlled gradient fields.
References Cited (Backward Citations)
US3510832A
Cited
US3564398A
Cited
US4284950A
Cited
US4417209A
Cited
US4424488A
Cited
GB2076540B
Cited
GB2076542B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-17 | 1990-05-19 | 1990-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-17 | 1994-05-19 | 1994-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-17 | 1998-05-19 | 1998-11-18 | $7700.00 | Window Closed / Lapsed |