US3753081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gyromagnetic resonance method and apparatus for obtaining spin-spin coupling constants
Assignee: Varian Medical Systems Inc
•
Filing: 1971-12-30
•
Granted: 1973-08-14
•
Expires: 1991-12-30
Abstract
Abstract Spin-spin coupling constants are obtained by exciting and detecting a decaying train of time displaced spin echo resonances of a plurality of spin-spin coupled groups of gyromagnetic resonators, such as a group of chemically shifted homonuclear atomic nuclei, within a sample under analysis. The envelope of the peak amplitude of the train of spin echo resonances decays and is modulated in accordance with the spin-spin coupling constants. The modulated envelope is Fourier analyzed to separate the individual Fourier frequency components, each component corresponding to one-half the sums and differences of the different spin-spin coupling constants, whereby a spectrum of spin-spin coupling constants is obtained which is free of magnetic field inhomogeneity effects and chemical shifts.
Inventors
- 👤 R Freeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:13
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4625
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
125 words
In a method for obtaining spin-spin coupling gyromagnetic resonance data from a sample of matter immersed in a polarizing magnetic field the steps of, exciting and detecting a sequence of time displaced spin echo resonances of a plurality of spin-spin coupled groups of gyromagnetic resonators within the sample, said sequence of detected spin echo resonances having an envelope of echo peak amplitude which is modulated in accordance with a plurality of spin-spin coupling constants between at least three groups of spin-spin coupled gyromagnetic resonators, and analyzing said modulation of said envelope of spin echo peak amplitude to separate at least one of the Fourier components thereof, whereby spin-spin coupling constant gyromagnetic resonance spectral data is obtained which is substantially free of magnetic field inhomogeneity effects.
Claim 2
Dependent Claim
125 words
In a method for obtaining spin-spin coupling gyromagnetic resonance data from a sample of matter immersed in a polarizing magnetic field the steps of, exciting and detecting a sequence of time displaced spin echo resonances of a plurality of spin-spin coupled groups of gyromagnetic resonators within the sample, said sequence of detected spin echo resonances having an envelope of echo peak amplitude which is modulated in accordance with a plurality of spin-spin coupling constants between at least three groups of spin-spin coupled gyromagnetic resonators, and analyzing said modulation of said envelope of spin echo peak amplitude to separate at least one of the Fourier components thereof, whereby spin-spin coupling constant gyromagnetic resonance spectral data is obtained which is substantially free of magnetic field inhomogeneity effects.
Claim 3
Dependent Claim
85 words
The method of claim 1 wherein the step of analyzing said modulation of said envelope of echo peak amplitude includes the step of, exciting forced precession of at least one of said spin-spin coupled groups of gyromagnetic resonators to decouple the spin of the forced precessional group of gyromagnetic resonators from at least two other groups of spin-spin coupled resonators to remove at least one of the Fourier components from said modulation of said envelope to simplify said analysis of said modulation of said envelope.
Claim 4
Dependent Claim
78 words
The method of claim 1 wherein the step of detecting said excited sequence of spin echo resonances includes the step of, selectively detecting said excited spin echo resonances within a band of gyromagnetic resonance frequencies which excludes at least the gyromagnetic resonance frequency of at least one of said excited groups of spin-spin coupled gyromagnetic resonators, whereby at least one spin-spin constant Fourier component is eliminated from said spin-spin coupling modulation of said envelope of spin echo amplitude.
Claim 5
Dependent Claim
36 words
The method of claim 1 wherein the step of analyzing said modulation of said envelope of spin echo peak amplitude includes the step of, Fourier transforming said modulation from the time domain to the frequency domain.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein said at least three groups of gyromagnetic resonators are separate chemically shifted groups of homonuclei.
Claim 7
Dependent Claim
139 words
In an apparatus for obtaining spin-spin coupling gyromagnetic resonance data from a sample of matter immersed in a polarizing magnetic field, means for exciting a sequencE of time displaced spin echo resonances of a plurality of spin-spin coupled gyromagnetic resonators within said sample, means for detecting said sequence of excited spin echo resonances and for producing an output in accordance with the envelope of detected peak echo amplitude, such envelope being modulated in accordance with at least one spin-spin coupling constant between at least a plurality of said excited groups of spin-spin coupled gyromagnetic resonators, and means for analyzing said detected modulation of said envelope of spin echo peak amplitude to separate at least one of the Fourier components therefrom, whereby spin-spin coupling constant gyromagnetic resonance spectral data is obtained which is substantially free of magnetic field inhomogeneity effects.
Claim 8
Dependent Claim
139 words
In an apparatus for obtaining spin-spin coupling gyromagnetic resonance data from a sample of matter immersed in a polarizing magnetic field, means for exciting a sequencE of time displaced spin echo resonances of a plurality of spin-spin coupled gyromagnetic resonators within said sample, means for detecting said sequence of excited spin echo resonances and for producing an output in accordance with the envelope of detected peak echo amplitude, such envelope being modulated in accordance with at least one spin-spin coupling constant between at least a plurality of said excited groups of spin-spin coupled gyromagnetic resonators, and means for analyzing said detected modulation of said envelope of spin echo peak amplitude to separate at least one of the Fourier components therefrom, whereby spin-spin coupling constant gyromagnetic resonance spectral data is obtained which is substantially free of magnetic field inhomogeneity effects.
Claim 9
Dependent Claim
53 words
The apparatus of claim 6 wherein said means for detecting said sequence of spin echoes and for producing an output in accordance with the envelope of detected peak echo amplitude includes, means for sampling the echo amplitude of said sequency of spin echos substantially only at the peak amplitude of each respective echo.
Claim 10
Dependent Claim
110 words
The apparatus of claim 6 wherein said sample includes at least three spin-spin coupled groups of gyromagnetic resonators to define at least three spin-spin coupling constants, and including means for exciting forced precession of at least one of said spin-spin coupled groups of gyromagnetic resonators during the sequence of spin echo resonance of at least the other two groups of resonators to decouple the spins of the forced precessional group of gyromagnetic resonators from at least the two other groups of spin-spin coupled resonators to remove at least one of the spin-spin coupling Fourier components from said modulation of said envelope to simplfy analysis of said modulation of said envelope.
Claim 11
Dependent Claim
78 words
The apparatus of claim 6 wherein said means for detecting said sequence of excited spin echo resonances includes, means for selectively detecting said excited spin echo resonances within a band of gyromagnetic resonance frequencies which excludes at least the gyromagnetic resonance frequency of at least one of said excited groups of spin-spin coupled gyromagnetic resonators, whereby at least one spin-spin coupling constant Fourier component is eliminated from said spin-spin coupling modulation of said envelope of peak echo amplitude.
Claim 12
Dependent Claim
49 words
The apparatus of claim 6 wherein said means for analyzing said detected modulation of said envelope of spin echo peak amplitude to separate at least one of the Fourier spin-spin coupling constant components therefrom includes, means for Fourier transforming said modulation from the time domain to the frequency domain.
Claim 13
Dependent Claim
15 words
The apparatus of claim 10 wherein said Fourier transforming means includes a programmed digital computer.
Claim 14
Dependent Claim
22 words
The apparatus of claim 6 wherein said spin-spin coupled groups of gyromagnetic resonators are separate chemically shifted homonuclear groups of atomic nuclei.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |