Patent US3033984A successfully refreshed from Google Patents.
EP0140259A2
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Transverse gradient field coil
Assignee: General Electric Co
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Filing: 1984-10-13
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Granted: —
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Expires: 2004-10-13
Abstract
Abstract Etching methods are employed on a thin conducting sheet so as to fabricate complicated magnetic coil patterns which are necessary to produce magnetic fields of high uniformity or other given design. The etching is performed so that material is removed along a thin line or lines which correspond to current streamlines of the ideal current distribution so that the remaining material exhibits a relatively wide region of conducting material having reduced electrical resistance. The coil winding patterns described are capable of producing transverse gradient magnetic fields with an exceedingly high degree of linearity in intensity with respect to a cylindrical coil form on which the RF and gradient coils are generally disposed.
Inventors
- 👤 William Alan Edelstein
- 👤 John Frederick Schenck
- 👤 Moayyed Abdulhassain Hussain
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 16:30
CPC Classifications
H; H01; H01F; H01F5/00; H01F7/00; H01F7/06; H01F7/20; G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/385; H01F41/00; H01F41/02; H01F41/04; H01F41/041; H01F41/045
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
57 words
A method for producing electrical circuits in which currents are specified as being continuously distributed on a surface, said method comprising the steps of: determining current streamlines corresponding to said specified current distributions; and removing a thin line of conductive material from a conductive layer mounted on an insulating substrate, said line corresponding to said current streamlines.
Claim 2
Independent Claim
57 words
A method for producing electrical circuits in which currents are specified as being continuously distributed on a surface, said method comprising the steps of: determining current streamlines corresponding to said specified current distributions; and removing a thin line of conductive material from a conductive layer mounted on an insulating substrate, said line corresponding to said current streamlines.
Claim 3
Dependent Claim
12 words
The method of claim 1 in which said conductive material comprises copper.
Claim 4
Dependent Claim
16 words
The method of claim 1 in which said removing step comprises etching of said conductive material.
Claim 5
Dependent Claim
26 words
The method of claim 3 in which said etching is performed using a mask produced from a photographically negative image of the said specified current streamline.
Claim 6
Dependent Claim
12 words
The method of claim 1 in which said substrate comprises flexible material.
Claim 7
Dependent Claim
11 words
The method of claim 1 in which said substrate is cylindrical.
Claim 8
Dependent Claim
17 words
The method of claim 1 further including the step of conforming said conductive layer to said surface.
Claim 9
Dependent Claim
127 words
A transverse gradient coil, especially a coil for use in nuclear magnetic resonance imaging systems, comprising: a cylindrical coil form of nonmagnetic material; and four winding loop sets disposed in both radially and longitudinally symmetric positions on said cylindrical coil form, each of said loop sets having a saddle shape configuration; each of said loop sets being configured to produce a surface current density vector o(z), where z is a measure of the position on said coil form along the axis of said cylinder, said current density having an anqular component σ φ (z) and a longitudinal component σ z (z), said σ φ (z) and σ z (z) being defined to be substantially as follows: and in which: σ z (z) beinq a mathematically continuous function.
Claim 10
Dependent Claim
127 words
A transverse gradient coil, especially a coil for use in nuclear magnetic resonance imaging systems, comprising: a cylindrical coil form of nonmagnetic material; and four winding loop sets disposed in both radially and longitudinally symmetric positions on said cylindrical coil form, each of said loop sets having a saddle shape configuration; each of said loop sets being configured to produce a surface current density vector o(z), where z is a measure of the position on said coil form along the axis of said cylinder, said current density having an anqular component σ φ (z) and a longitudinal component σ z (z), said σ φ (z) and σ z (z) being defined to be substantially as follows: and in which: σ z (z) beinq a mathematically continuous function.
Claim 11
Dependent Claim
21 words
9 . The transverse gradient coil of claim 1 in which said winding loop sets comprise flexible printed circuit winding patterns.
Claim 12
Dependent Claim
42 words
10, The transverse gradient coil of claim 2 further includinq a second set of four winding loop sets having the same configuration as said first set of four winding loop sets but disposed at a different position, circumferentially, on said coil form.
Claim 13
Dependent Claim
47 words
11 , The transverse gradient coil of claim 3 in which said two sets of four winding loop sets are oriented so as to produce gradient fields oriented at right angles with respect to each other, whereby both x and y transverse radiant magnetic fields are provided.
Claim 14
Dependent Claim
23 words
The transverse gradient coil of claim 1 in which at least one of said four loop sets is disposed in a spiral pattern.
Claim 15
Dependent Claim
152 words
A transverse gradient coil, especially a coil for use in nuclear magnetic resonance imaging systems, comprising: a cylindrical coil form of nonmagnetic material; and four main winding loop sets disposed in both radially and longitudinally symmetric positions on said cylindrical coil form, each of said loop sets having a saddle shape configuration; each one of said four winding loop sets lying on the surface of said form, said sets being configured in a sequence of arcuate sections exhibiting increasing diameters in.a longitudinal direction along said coil form, toward the mid-portion thereof, each of said arcuate sections exhibiting an increasingly rectangular shape in said longitudinal direction toward the mid-portion of said coil form, said diameters of said arcuate sections being disposed along a single semicircular arc on said form; and arcuate current return paths lying on the surface of said form forming four spirally wound loop sets with said main winding loop sets.
Claim 16
Dependent Claim
152 words
A transverse gradient coil, especially a coil for use in nuclear magnetic resonance imaging systems, comprising: a cylindrical coil form of nonmagnetic material; and four main winding loop sets disposed in both radially and longitudinally symmetric positions on said cylindrical coil form, each of said loop sets having a saddle shape configuration; each one of said four winding loop sets lying on the surface of said form, said sets being configured in a sequence of arcuate sections exhibiting increasing diameters in.a longitudinal direction along said coil form, toward the mid-portion thereof, each of said arcuate sections exhibiting an increasingly rectangular shape in said longitudinal direction toward the mid-portion of said coil form, said diameters of said arcuate sections being disposed along a single semicircular arc on said form; and arcuate current return paths lying on the surface of said form forming four spirally wound loop sets with said main winding loop sets.
Claim 17
Dependent Claim
92 words
An NMR imaging system comprising: means for providing a constant magnetic field in a longitudinal direction; radio frequency means for exciting nuclear spins within a sample volume within said constant magnetic field; detector means for receiving radio frequency signals emitted by said excited nuclei; means for providing a gradient magnetic field in said longitudinal direction; means for providing gradient magnetic fields in at least two distinct directions, said directions being transverse to said longitudinal direction, at least one of said transverse gradient magnetic fields being provided by the coil of claim 6.
References Cited (Backward Citations)
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