Patent EP0170514A2 successfully refreshed from Google Patents.
EP0170514A2
Expired / Lapsed
EP
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Method and apparatus for obtaining N.M.R. spectra and coils for use therein
Assignee: Oxford Research Systems Ltd
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Filing: 1985-07-29
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Granted: —
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Expires: 2005-07-29
Abstract
Abstract Apparatus for obtaining an N.M.R. spectrum comprises two Rf coils (1) and (2), connected to an Rf source (54). Switches (15) and (16) inserted between the Rf coils (1) and (2) and ground at the end of coaxial cables (10) and (11) having a length of 4 allow the coils (1) and (2) to be tuned and detuned at will. The detune switches (15) and (16) essentially eliminate coupling between adjacent coils permitting operation of multiple transmit coils at the same frequency. There are important uses in in-vivo spectroscopy.
Inventors
- 👤 Max Robin Bendall
- 👤 Jamie M. Mckendry
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 08:53
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/34; G01R33/341; G01R33/34046; G01R33/36; G01R33/3628; G01R33/44; G01R33/46; G01R33/465; G01R33/48; G01R33/483; G01R33/4831
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
121 words
Apparatus for obtaining an N.M.R. spectrum of a sample, which apparatus comprises means for generating a static magnetic field, a sample location space within the magnetic field for containing the sample, means for applying to the space an Rf field having a wavelength such as to cause perturbation of nuclear spins in the sample space in the presence of the magnetic field, and means for detecting the Rf signal induced in the sample as a consequence of the applied Rf field, the apparatus comprising at least two tuned Rf coils, at least one of the said Rf coils being connected to ground via switching means, whereby operation of the switching means causes the detuning of the said at least one coil.
Claim 2
Dependent Claim
121 words
Apparatus for obtaining an N.M.R. spectrum of a sample, which apparatus comprises means for generating a static magnetic field, a sample location space within the magnetic field for containing the sample, means for applying to the space an Rf field having a wavelength such as to cause perturbation of nuclear spins in the sample space in the presence of the magnetic field, and means for detecting the Rf signal induced in the sample as a consequence of the applied Rf field, the apparatus comprising at least two tuned Rf coils, at least one of the said Rf coils being connected to ground via switching means, whereby operation of the switching means causes the detuning of the said at least one coil.
Claim 3
Dependent Claim
60 words
Apparatus as claimed in Claim 1, wherein the switching means includes a transmission line having its conductors connected respectively to the said at least one coil and ground at one of its ends, and being provided with a switch at its other end, the transmission line having a length equivalent to an integral multiple of quarters of the said wavelength.
Claim 4
Dependent Claim
19 words
Apparatus as claimed in Claim 1 or Claim 2, wherein the transmission line is a length of coaxial cable.
Claim 5
Dependent Claim
26 words
Apparatus as claimed in any one of Claims 1 to 3, wherein at least two RF coils are provided with switching means of the said kind.
Claim 6
Dependent Claim
42 words
Apparatus as claimed in any one of Claims 1 to 4 for obtaining an N.M.R. spectrum of a portion of a human body, comprising means for supporting the human body with the said portion of the human body in the sample space.
Claim 7
Dependent Claim
13 words
Apparatus as claimed in Claim 5, wherein the said portion is the head.
Claim 8
Dependent Claim
47 words
A coil assembly for use in an N.M.R. spectrometer, comprising at least two pairs of complimentary electrical coils, the coils being arranged in a non-coplanar 'flower-petal' configuration, with coils corresponding to diametrically opposite petals connected together such that the same electrical current flows in diametrically opposed coils.
Claim 9
Dependent Claim
47 words
A coil assembly for use in an N.M.R. spectrometer, comprising at least two pairs of complimentary electrical coils, the coils being arranged in a non-coplanar 'flower-petal' configuration, with coils corresponding to diametrically opposite petals connected together such that the same electrical current flows in diametrically opposed coils.
Claim 10
Dependent Claim
38 words
A coil assembly as claimed in Claim 7, wherein coils of the assembly corresponding to diametrically opposed petals are corrected such that electrical current flows in the same direction about an axis passing through the diametrically opposed coils.
Claim 11
Dependent Claim
20 words
A coil assembly as claimed in Claim 7 or Claim 8, wherein the number of pairs of coils is two.
Claim 12
Dependent Claim
24 words
A coil assembly as claimed in Claim 9, wherein the axes of the said coil pairs are substantially at right angles to each other.
Claim 13
Dependent Claim
28 words
A coil assembly as claimed in any one of Claims 7 to 10, wherein the two coils of each pair are substantially at right angles to each other.
Claim 14
Dependent Claim
48 words
A coil assembly as claimed in any one of Claims 7 to 11, wherein the coils aranged in the 'flower-petal' configuration have an axis of symmetry, and wherein the assembly comprises an additional coil, the additional coil being disposed in a plane perpendicular to the axis of symmetry.
Claim 15
Dependent Claim
25 words
Apparatus as claimed in any one of Claims 1 to 6, including a coil assembly as claimed in any one of Claims 7 to 12.
Claim 16
Dependent Claim
22 words
Apparatus as claimed in Claim 13, wherein the coils constituting the said 'flower-petal' configuration are connected to ground via the said switch.
Claim 17
Dependent Claim
46 words
Apparatus as claimed in Claim 13, wherein the coil assembly is as defined in Claim 12, all the coils arranged in the said 'flower-petal' configuration are connected to ground via first switching means, and the said additional coil is connected to ground via second switching means.
Claim 18
Independent Claim
30 words
A method of detuning a radiofrequency coil during a pulsed nuclear magnetic resonance procedure of sample analysis which method comprises operating a switch provided between the radiofrequency coil and ground.
Claim 19
Independent Claim
30 words
A method of detuning a radiofrequency coil during a pulsed nuclear magnetic resonance procedure of sample analysis which method comprises operating a switch provided between the radiofrequency coil and ground.
Claim 20
Dependent Claim
41 words
A method as claimed in Claim 16, wherein the switch is connected at one end of an electrical transmission line across the electrical conductors at the other end of the transmission line being connected respectively to the coil and to ground.
Claim 21
Dependent Claim
35 words
A method as claimed in Claim 17, wherein the transmission line is a length of coaxial cable, the inner conductor of this coaxial cable being connected to the coil, and the outer conductor to ground.
Claim 22
Dependent Claim
38 words
A method as claimed in Claim 16 or Claim 17, wherein the length of the transmission line is approximately equal to an integral number of quarter wavelengths of the radiofrequency used in the coil, in the tranmission line.
Claim 23
Dependent Claim
13 words
A method as claimed in Claim 19, wherein the integral number is one.
Claim 24
Dependent Claim
30 words
A method as claimed in any one of Claims 16 to 20, wherein at least two radiofrequency coils are provided, each having a switch arrangement as defined in Claim 1.
Claim 25
Independent Claim
30 words
A method of obtaining an N.M.R. signal which method includes the step of detuning a radiofrequency coil, by a method as claimed in any one of Claims 16 to 21.
References Cited (Backward Citations)
No citation records indexed.
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