US4994743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for monitoring respiration with acquired NMR data
Assignee: General Electric Co
•
Filing: 1989-10-27
•
Granted: 1991-02-19
•
Expires: 2009-10-27
Abstract
Abstract NMR data indicative of the motion of the anterior abdominal wall of a subject is acquired just prior to each image data pulse sequence in an NMR scan. The acquired motion NMR data is processed on-line to produce a signal indicative of the displacement of the abdominal wall from a reference position. The displacement values may be employed to produce a signal indicative of a respiration phase that can be used in connection with motion artifact reduction techniques.
Inventors
- 👤 Gary H. Glover
- 👤 Stephen W. Flax
- 👤 Ann Shimakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:25
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/567; G01R33/5676; A; A61; A61B; A61B6/00; A61B6/54; A61B6/541
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
A system for providing respiratory phase information during an NMR scan of a subject, which comprises: means for producing an NMR motion pulse sequence during the NMR image data scan; means for acquiring the NMR motion signals produced by said NMR motion pulse sequence; means for processing the motion NMR signals to produce a data set which indicates the position of features in the subject; means for locating the position of a specific feature in said data set; and means for producing a respiratory signal by correlating the current position of the specific feature with a reference position for that feature.
Claim 2
Independent Claim
101 words
A system for providing respiratory phase information during an NMR scan of a subject, which comprises: means for producing an NMR motion pulse sequence during the NMR image data scan; means for acquiring the NMR motion signals produced by said NMR motion pulse sequence; means for processing the motion NMR signals to produce a data set which indicates the position of features in the subject; means for locating the position of a specific feature in said data set; and means for producing a respiratory signal by correlating the current position of the specific feature with a reference position for that feature.
Claim 3
Dependent Claim
40 words
The system as recited in claim 1 in which the means for processing the motion NMR signals includes means for performing a Fourier transformation along a dimension which corresponds to the axis along which the position of features is measured.
Claim 4
Dependent Claim
74 words
The system as recited in claim 2 in which the means for producing the NMR motion pulse sequence includes means for producing an RF excitation pulse which produces transverse magnetization in spins contained in the subject, and means for producing a magnetic field gradient along said axis; and the means for acquiring the NMR motion signals includes means for receiving and digitizing the NMR motion signals while said magnetic field gradient is being produced.
Claim 5
Dependent Claim
24 words
The system as recited in claim 1 in which the specific feature in the subject is the anterior abdominal wall of a human subject.
Claim 6
Dependent Claim
61 words
The system as recited in claim 1 in which the NMR scan is comprised of a series of NMR image pulse sequences and an NMR motion pulse sequence is produced prior to each such NMR image pulse sequence and the data acquired therefrom is used to produce said respiratory signal prior to the production of the following NMR image pulse sequence.
Claim 7
Dependent Claim
60 words
The system as recited in claim 1 in which the NMR scan is comprised of a series of NMR image pulse sequences and an NMR motion pulse sequence is produced following each such NMR image pulse sequence and the data acquired therefrom is used to produce said respiratory signal prior to the production of the following NMR image pulse sequence.
References Cited (Backward Citations)
USRE32701E
Cited
US4564017A
Cited
US4567893A
Cited
US4724386A
Cited
US4710717A
Cited
US4761613A
Cited
US4857846A
Cited
US4937526A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-18 | 2002-08-20 | 2003-02-19 | $7700.00 | Window Closed / Lapsed |