Patent US1925565A successfully refreshed from Google Patents.
US6885192B2
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SQUID detected NMR and MRI at ultralow fields
Assignee: University of California
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Filing: 2003-02-06
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Granted: 2005-04-26
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Expires: 2023-02-06
Abstract
Abstract Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned de superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.
Inventors
- 👤 John Clarke
- 👤 Robert McDermott
- 👤 Alexander Pines
- 👤 Andreas Heinz Trabesinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 01:31
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/323; G01R33/326; G01R33/02; G01R33/035; G01R33/0354; G01R33/0356; G01R33/44; G01R33/445
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
61 words
A method for nuclear magnetic resonance (NMR) of a sample in an ambient room temperature environment, comprising: prepolarizing nuclear spins in the sample in a millitesla magnetic field; detecting nuclear magnetic resonance (NMR) signals from the sample in the ambient room temperature environment in a microtesla magnetic field with an untuned low critical temperature (Tc) superconducting quantum interference device (SQUID) magnetometer.
Claim 2
Independent Claim
61 words
A method for nuclear magnetic resonance (NMR) of a sample in an ambient room temperature environment, comprising: prepolarizing nuclear spins in the sample in a millitesla magnetic field; detecting nuclear magnetic resonance (NMR) signals from the sample in the ambient room temperature environment in a microtesla magnetic field with an untuned low critical temperature (Tc) superconducting quantum interference device (SQUID) magnetometer.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the detecting magnetic field is in the range of about 150 μT to about 1 μT.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein the prepolarizing magnetic field is tens of mT.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein the SQUID is maintained substantially at liquid helium temperature and the sample is at room temperature.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein the prepolarization is performed by resonant spin manipulation and the prepolarization and detection fields are orthogonal.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein the prepolarization is performed by nonresonant spin manipulation and the prepolarization and detection fields are parallel.
Claim 8
Dependent Claim
13 words
The method of claim 1 wherein the detection magnetic field is substantially inhomogeneous.
Claim 9
Dependent Claim
15 words
The method of claim 1 further comprising operating the SQUID in a flux locked mode.
Claim 10
Dependent Claim
31 words
The method of claim 8 wherein the output of the SQUID is amplified, integrated, and then fed back to a flux modulating coil positioned near the input coil of the SQUID.
Claim 11
Dependent Claim
24 words
The method of claim 1 further comprising performing magnetic resonance imaging (MRI) of the sample by forming an image from the detected NMR signals.
Claim 12
Dependent Claim
15 words
The method of claim 10 further comprising applying encoding magnetic field gradients to the sample.
Claim 13
Dependent Claim
11 words
The method of claim 1 further comprising simultaneously detecting multinuclear species.
Claim 14
Dependent Claim
16 words
The method of claim 1 further comprising obtaining scalar (“J”) coupling information from the NMR signals.
Claim 15
Dependent Claim
14 words
The method of claim 13 , comprising following a reporter nucleus through bond formation.
Claim 16
Dependent Claim
17 words
The method of claim 13 , comprising identifying specific covalent bonds from said scalar (“J”) coupling information.
Claim 17
Dependent Claim
16 words
The method of claim 1 , wherein a strength of said detecting magnetic field is adjustable.
Claim 18
Dependent Claim
30 words
The method of claim 16 , comprising adjusting said strength of said detecting magnetic field in response to inhomogeneous broadening due to spurious gradients generated by a measurement field coil.
Claim 19
Dependent Claim
29 words
The method of claim 16 , comprising adjusting said strength of said detecting magnetic field in response to a level of environmental interference and noise over a signal band.
Claim 20
Dependent Claim
35 words
The method of claim 16 , comprising adjusting said strength of said detecting magnetic field in response to a strength of field generated by gradient coils relative to said strength of said detecting magnetic field.
Claim 21
Dependent Claim
19 words
The method of claim 1 , comprising isolating said SQUID magnetometer from amplifier noise by means of mechanical relays.
Claim 22
Dependent Claim
20 words
The method of claim 20 , wherein isolating said SQUID magnetometer comprises opening mechanical relays in series with polarizing coils.
Claim 23
Dependent Claim
20 words
The method of claim 20 , wherein isolating the SQUID magnetometer comprises opening mechanical relays in series with echo coils.
Claim 24
Dependent Claim
24 words
The method of claim 1 , comprising performing magnetic resonance imaging (MRI): of the sample by forming an image from the detected NMR signals.
Claim 25
Dependent Claim
16 words
The method of claim 23 , comprising performing magnetoencephalography (MEG) with an array of SQUID sensors.
Claim 26
Dependent Claim
19 words
The method of claim 24 , wherein said array of SQUID sensors is also used to perform the MRI.
Claim 27
Dependent Claim
19 words
The method of claim 25 , wherein the MRI and the MEG are performed in a single time period.
Claim 28
Dependent Claim
16 words
The method of claim 24 , comprising averaging signals received from said array of SQUID sensors.
Claim 29
Dependent Claim
77 words
Apparatus for nuclear magnetic resonance (NMR) of a sample in an ambient room temperature environment, comprising: prepolarization coils for providing a millitesla magnetic field for prepolarizing nuclear spins in the sample; measurement coils for providing a microtesla magnetic field for detecting nuclear magnetic resonance (NMR) signals from the sample in the ambient room temperature environment; an untuned low critical temperature (Tc) superconducting quantum interference device (SQUID) magnetometer for detecting nuclear magnetic resonance (NMR) signals from the sample.
Claim 30
Dependent Claim
77 words
Apparatus for nuclear magnetic resonance (NMR) of a sample in an ambient room temperature environment, comprising: prepolarization coils for providing a millitesla magnetic field for prepolarizing nuclear spins in the sample; measurement coils for providing a microtesla magnetic field for detecting nuclear magnetic resonance (NMR) signals from the sample in the ambient room temperature environment; an untuned low critical temperature (Tc) superconducting quantum interference device (SQUID) magnetometer for detecting nuclear magnetic resonance (NMR) signals from the sample.
Claim 31
Dependent Claim
15 words
The apparatus of claim 28 further comprising a flux locked loop connected to the SQUID.
Claim 32
Dependent Claim
31 words
The apparatus of claim 28 wherein the detecting magnetic field is in the range of about 150 μT to about 1 μT and the prepolarizing magnetic field is tens of mT.
Claim 33
Dependent Claim
32 words
The apparatus of claim 28 further comprising a liquid helium dewar in which the SQUID is mounted to maintain the SQUID at liquid helium temperature while the sample is at room temperature.
Claim 34
Dependent Claim
26 words
The apparatus of claim 28 further comprising means to perform magnetic resonance imaging (MRI) of the sample by forming an image from the detected NMR signals.
Claim 35
Dependent Claim
15 words
The apparatus of claim 32 wherein the means to perform MRI include gradient field coils.
Claim 36
Dependent Claim
13 words
The apparatus of claim 32 further comprising a SQUID array for performing magnetoencephalography.
Claim 37
Dependent Claim
16 words
The apparatus of claim 34 , wherein said means to perform MRI comprises said SQUID array.
Claim 38
Dependent Claim
16 words
The apparatus of claim 35 , wherein said means to perform MRI further comprises a gradiometer.
Claim 39
Dependent Claim
16 words
The apparatus of claim 36 , wherein the gradiometer has a diameter up to 160 mm.
Claim 40
Independent Claim
97 words
An apparatus for performing magnetic resonance imaging (MRI) and magnetoencephalography (MEG) on a subject in an ambient room temperature environment, the apparatus comprising: a) prepolarizing coils for providing a prepolarizing magnetic field for prepolarizing nuclear spins in the subject; b) measurement coils for providing a detecting magnetic field for generating nuclear magnetic resonance (NMR) signals in the subject; and c) an array of superconducting quantum interference devices (SQUIDs) for performing MRI on the subject by forming an image from said NMR signals and for performing MEG on the subject by measuring biomagnetic signals generated within the subject.
Claim 41
Independent Claim
97 words
An apparatus for performing magnetic resonance imaging (MRI) and magnetoencephalography (MEG) on a subject in an ambient room temperature environment, the apparatus comprising: a) prepolarizing coils for providing a prepolarizing magnetic field for prepolarizing nuclear spins in the subject; b) measurement coils for providing a detecting magnetic field for generating nuclear magnetic resonance (NMR) signals in the subject; and c) an array of superconducting quantum interference devices (SQUIDs) for performing MRI on the subject by forming an image from said NMR signals and for performing MEG on the subject by measuring biomagnetic signals generated within the subject.
Claim 42
Dependent Claim
21 words
The apparatus of claim 38 , wherein said array of SQUIDs comprises an array of low critical temperature untuned SQUID magnetometers.
Claim 43
Dependent Claim
21 words
The apparatus of claim 38 , wherein said array of SQUIDs comprises an array of low critical temperature untuned SQUID gradiometers.
Claim 44
Dependent Claim
23 words
The apparatus of claim 38 , wherein said detecting magnetic field is in the range of about 150 μT to about 1 μT.
Claim 45
Dependent Claim
15 words
The apparatus of claim 41 , wherein said prepolarizing magnetic field is tens of mT.
Claim 46
Dependent Claim
40 words
The apparatus of claim 38 , comprising a liquid helium dewar in which said array of SQUIDs is mounted to maintain said array of SQUIDs at liquid helium temperature while the subject's head is in the ambient room temperature environment.
Claim 47
Dependent Claim
17 words
The apparatus of claim 38 , comprising means for adjusting a strength of said detecting magnetic field.
Claim 48
Dependent Claim
17 words
The apparatus of claim 38 , comprising means for averaging signals received by said array of SQUIDs.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2008-04-25 | 2008-10-25 | 2009-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-04-25 | 2012-10-25 | 2013-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-04-25 | 2016-10-25 | 2017-04-26 | $7700.00 | Window Closed / Lapsed |