US4851777A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduced noise NMR localization system
Assignee: Leland Stanford Junior University
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Filing: 1988-04-11
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Granted: 1989-07-25
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Expires: 2008-04-11
Abstract
Abstract Magnetic resonance signals are received using a plurality of coils, each sensitive to different but overlapping regions of the volume being studied. The signals are combined so as to cancel in undesired regions of the body and receive net signals from only desired parts of the volume to enhance the signal-to-noise ratio for imaging and spectroscopy.
Inventors
- 👤 Albert Macovski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:17
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/28; G01R33/32; G01R33/34; G01R33/341; G01R33/3415
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
108 words
In a method for isolating nuclear magnetic resonance signals from a limited region in a volume the steps of receiving signals from a plurality of coils where all coils receive signals from different but overlapping portions of the volume including said limited region, weighting said received signals whereby signals from outside of said limited region can be suppressed and signals from said limited region can be enhanced, and combining the weighted signals to provide an increased signal-to-noise ratio nuclear magnetic resonance signal from said limited region of interest including adding weighted signals from said limited region and subtracting weighted signals from outside of said limited region of interest.
Claim 2
Dependent Claim
108 words
In a method for isolating nuclear magnetic resonance signals from a limited region in a volume the steps of receiving signals from a plurality of coils where all coils receive signals from different but overlapping portions of the volume including said limited region, weighting said received signals whereby signals from outside of said limited region can be suppressed and signals from said limited region can be enhanced, and combining the weighted signals to provide an increased signal-to-noise ratio nuclear magnetic resonance signal from said limited region of interest including adding weighted signals from said limited region and subtracting weighted signals from outside of said limited region of interest.
Claim 3
Dependent Claim
93 words
In a method for isolating nuclear magnetic resonance signals from a limited region in a volume the steps of receiving signals from a plurality of coils where all coils receive signals from different but overlapping portions of the volume, weighting said received signals to isolate a limited region of interest in said volume, and combining the received signals to provide an increased signal-to-noise ratio nuclear magnetic resonance signal from said limited region of interest, including the step of subtracting at least one of the received signals from at least one other received signal.
Claim 4
Dependent Claim
93 words
In a method for isolating nuclear magnetic resonance signals from a limited region in a volume the steps of receiving signals from a plurality of coils where all coils receive signals from different but overlapping portions of the volume, weighting said received signals to isolate a limited region of interest in said volume, and combining the received signals to provide an increased signal-to-noise ratio nuclear magnetic resonance signal from said limited region of interest, including the step of subtracting at least one of the received signals from at least one other received signal.
Claim 5
Dependent Claim
20 words
The method as defined by claim 2 wherein said signals are weighted prior to the step of combining said signals.
Claim 6
Dependent Claim
24 words
The method as defined by claim 3 wherein said signals are weighted by the number of turns in each of said plurality of coils.
Claim 7
Dependent Claim
20 words
The method as described in claim 4 where the step of combining includes the step of connecting the coils together.
Claim 8
Dependent Claim
32 words
The method as described in claim 3 where the step of combining includes the step of applying the output of each coil to an amplifier and combining the outputs of the amplifiers.
Claim 9
Dependent Claim
34 words
The method as described in claim 1 where the step of combining includes the step of sequentially combining combinations of different coils whereby a region of the volume is imaged with high signal-to-noise ratio.
Claim 10
Dependent Claim
106 words
Apparatus for isolating nuclear magnetic signals from a limited region in a volume comprising: a plurality of coils positioned adjacent the volume to receive signals from different but overlapping portions of the volume including said limited region, means for receiving and weighting signals from each coil including said limited region; and means for combining the weighted signals to provide high sensitivity in said limited region and low sensitivity outside of said limited region whereby the signal-to-noise ratio in the desired portion is increased, said means for combining adding weighted signals from said limited region and subtracting weighted signals from outside of said limited region of interest.
Claim 11
Dependent Claim
106 words
Apparatus for isolating nuclear magnetic signals from a limited region in a volume comprising: a plurality of coils positioned adjacent the volume to receive signals from different but overlapping portions of the volume including said limited region, means for receiving and weighting signals from each coil including said limited region; and means for combining the weighted signals to provide high sensitivity in said limited region and low sensitivity outside of said limited region whereby the signal-to-noise ratio in the desired portion is increased, said means for combining adding weighted signals from said limited region and subtracting weighted signals from outside of said limited region of interest.
Claim 12
Dependent Claim
27 words
Apparatus as described in claim 8 where the means for combining includes means for subtracting at least one received signal from at least one other received signal.
Claim 13
Dependent Claim
58 words
Apparatus for isolating nuclear magnetic signals from a limited region in a volume comprising: a plurality of coils positioned adjacent the volume; means for receiving signals from each coil; means for weighting said signals, and means for combining the received signals and including means for subtracting at least one received signal from at least one other received signal.
Claim 14
Dependent Claim
58 words
Apparatus for isolating nuclear magnetic signals from a limited region in a volume comprising: a plurality of coils positioned adjacent the volume; means for receiving signals from each coil; means for weighting said signals, and means for combining the received signals and including means for subtracting at least one received signal from at least one other received signal.
Claim 15
Dependent Claim
20 words
Apparatus as defined in claim 10 wherein said plurality of coils have selected numbers of turns for weighting said signals.
Claim 16
Dependent Claim
18 words
Apparatus as described in claim 11 where the means for combining includes means for connecting the coils together.
Claim 17
Dependent Claim
30 words
Apparatus as described in claim 11 where the means for combining includes means for applying the output of each coil to an amplifier and combining the outputs of the amplifiers.
Claim 18
Dependent Claim
12 words
Apparatus as described in claim 13 where the amplifiers have controlled gain.
Claim 19
Dependent Claim
72 words
Apparatus for isolating nuclear magnetic signals from a limited region in a volume comprising: a plurality of coils positioned adjacent the volume; means for receiving and weighting signals from each coil; and means for combining the weighted signals including means for sequentially adding and subtracting combinations of weighted signals from different coils thereby providing high sensitivity in said limited region of the volume and increasing the signal-to-noise ratio in said limited region.
Claim 20
Dependent Claim
72 words
Apparatus for isolating nuclear magnetic signals from a limited region in a volume comprising: a plurality of coils positioned adjacent the volume; means for receiving and weighting signals from each coil; and means for combining the weighted signals including means for sequentially adding and subtracting combinations of weighted signals from different coils thereby providing high sensitivity in said limited region of the volume and increasing the signal-to-noise ratio in said limited region.
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) | 1992-07-24 | 1993-01-23 | 1993-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-24 | 1997-01-23 | 1997-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-24 | 2001-01-23 | 2001-07-25 | $7700.00 | Window Closed / Lapsed |