Patent US4564017A successfully refreshed from Google Patents.
US4564017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for respiration monitoring with an NMR scanner
Assignee: General Electric Co
•
Filing: 1984-11-21
•
Granted: 1986-01-14
•
Expires: 2004-11-21
Abstract
Abstract A method for eliminating or reducing breathing artifacts due to motion-induced phase and amplitude errors in the phase-encoding dimension when using Fourier transform imaging methods, such as spin warp, utilizes a repetition time (TR) which is an odd multiple of one quarter of the breathing cycle. In the preferred embodiment, method and apparatus are provided for determining the breathing cycle by monitoring the integrated spin-echo signal magnitude spectrum as a function of time.
Inventors
- 👤 Gary H. Glover
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:02
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/567; G01R33/5676; A; A61; A61B; A61B5/00; A61B5/08; A61B5/0816; A61B5/72; A61B5/7203; A61B5/7207; A61B5/7235; A61B5/7253; A61B5/7257; A61B5/7242
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
49 words
A method of determining the respiration period of a patient using scan data obtained with an NMR scanner, said method comprising the steps of: acquiring amplitude-modulated NMR scan data of a predetermined region of the patient; and analyzing said scan data to derive the respiration rate of the patient.
Claim 2
Independent Claim
49 words
A method of determining the respiration period of a patient using scan data obtained with an NMR scanner, said method comprising the steps of: acquiring amplitude-modulated NMR scan data of a predetermined region of the patient; and analyzing said scan data to derive the respiration rate of the patient.
Claim 3
Dependent Claim
45 words
The method of claim 1 wherein said step of acquiring comprises scanning the patient with a Fourier transform pulse sequence having a plurality of views, and wherein the scan data comprises spin-echo signals acquired in the absence of phase-encoding variable amplitude magnetic field gradient pulses.
Claim 4
Dependent Claim
30 words
The method of claim 2 wherein said step of analyzing comprises: determining the spin-echo modulus, M i , to ascertain the cyclic character thereof and estimating therefrom the respiration period.
Claim 5
Dependent Claim
40 words
The method of claim 3 wherein the spin-echo modulus is determined using equation ##EQU3## where T s is the spin-echo sampling rate and R(S i ) and I(S i ) designate real and imaginary parts of the complex spin echo.
Claim 6
Dependent Claim
49 words
The method of claim 3 wherein the spin-echo modulus is determined using equation ##EQU4## where N s is the number of times each spin-echo signal is sampled and R(S i (t k )) and I(S i (t k )) designate real and imaginary parts of the complex spin echo.
Claim 7
Dependent Claim
68 words
The method of claim 2 wherein said step of analyzing comprises: determining the spin-echo modulus, M i ; taking the Fourier transform of M i with respect to time to determine the spectral density (F K ) of M i ; and identifying a spectrum component having maximum magnitude at the lowest frequency, wherein the time of occurrence of said spectrum component is taken as the respiration period.
Claim 8
Dependent Claim
40 words
The method of claim 6 wherein the spin-echo modulus is determined using equations ##EQU5## where T s is the spin-echo sampling duration and R(S i ) and I(S i ) designate real and imaginary parts of the complex spin echo.
Claim 9
Dependent Claim
49 words
The method of claim 6 wherein the spin-echo modulus is determined using equation ##EQU6## where N s is the number of times each spin-echo signal is sampled and R(S i (t k )) and I(S i (t k )) designate real and imaginary parts of the complex spin echo.
Claim 10
Dependent Claim
49 words
Apparatus for determining the respiration period of a patient using scan data obtained with an NMR scanner, said apparatus comprising: means for acquiring amplitude-modulated NMR scan data of a predetermined region of the patient; and means for analyzing said scan data to derive the respiration rate of the patient.
Claim 11
Dependent Claim
49 words
Apparatus for determining the respiration period of a patient using scan data obtained with an NMR scanner, said apparatus comprising: means for acquiring amplitude-modulated NMR scan data of a predetermined region of the patient; and means for analyzing said scan data to derive the respiration rate of the patient.
Claim 12
Dependent Claim
47 words
The apparatus of claim 9 wherein said means for acquiring comprises means for scanning the patient with a Fourier transform pulse sequence having a plurality of views, and wherein the scan data comprises spin-echo signals acquired in the abscence of phase-encoding variable amplitude magnetic field gradient pulses.
Claim 13
Dependent Claim
32 words
The apparatus of claim 10 wherein said means for analyzing comprises: means for determining the spin-echo modulus, M i , to ascertain the cyclic character thereof and estimating therefrom the respiration period.
Claim 14
Dependent Claim
74 words
The apparatus of claim 10 wherein said means for analyzing comprises: means for determining the spin-echo modulus, M i ; means for taking the Fourier transform of M i with respect to time to determine the spectral density (F K ) of M i ; and means for identifying a spectrum component having maximum magnitude at the lowest frequency, wherein the time of occurrence of said spectrum component is taken as the respiration period.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-13 | 1989-07-15 | 1990-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-13 | 1993-07-15 | 1994-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-13 | 1997-07-15 | 1998-01-14 | $7700.00 | Window Closed / Lapsed |