David Charles Ryan

US Patent:

6850066, Feb 1, 2005

Filed:

May 15, 2003

Appl. No.:

10/438523

Inventors:

Timothy J. Havens - Florence SC, US
Xianrui Huang - Clifton Park NY, US
David T Ryan - Niskayuna NY, US

Assignee:

GE Medical Systems Global Technology Company LLC - Waukesha WI

International Classification:

G01V 300

US Classification:

324318, 324322

Abstract:

A gradient compensation system comprising a magnet assembly, at least one field-generating gradient coil operable for generating magnetic field gradients in three orthogonal coordinates, and at least one gradient compensation coil positioned adjacent to the magnet assembly and operable for generating a magnetic field to compensate for leakage fields. A system for eliminating image distortion in magnetic resonance imaging comprising a magnet assembly comprising an imaging gradient coil and an imaging volume, and at least one gradient compensation coil positioned adjacent to the magnet assembly operable for generating gradient compensation fields in response to the magnetic field change. A method for counter-acting unwanted fields generated by eddy currents in conducting structures of a magnetic resonance system comprising generating a magnetic field change signal indicative of a change in a magnetic field of an imaging volume, determining a compensation signal in response to the magnetic field change signal, adding at least one gradient compensation coil to the magnetic resonance imaging system, and controlling current through the at least one gradient compensation coil.

US Patent:

6900714, May 31, 2005

Filed:

Jun 30, 2004

Appl. No.:

10/882024

Inventors:

Xianrui Huang - Clifton Park NY, US
Evangelos Trifon Laskaris - Schenectady NY, US
Kiruba Haran Sivasubramaniam - Clifton Park NY, US
James William Bray - Niskayuna NY, US
David Thomas Ryan - Niskayuna NY, US
James Michael Fogarty - Schenectady NY, US
Albert Eugene Steinbach - Schenectady NY, US

Assignee:

General Electric Company - Niskayuna NY

International Classification:

H01F006/00
H02H007/00
H02H009/00

US Classification:

335216, 310 52, 310 53, 310 54, 62 471, 62 511, 505850, 505879, 505885, 505892, 505893, 361 19

Abstract:

A system and method for protecting a superconductor. The system may comprise a current sensor operable to detect a current flowing through the superconductor. The system may comprise a coolant temperature sensor operable to detect the temperature of a cryogenic coolant used to cool the superconductor to a superconductive state. The control circuit is operable to estimate the superconductor temperature based on the current flow and the coolant temperature. The system may also be operable to compare the estimated superconductor temperature to at least one threshold temperature and to initiate a corrective action when the superconductor temperature exceeds the at least one threshold temperature.

US Patent:

7053509, May 30, 2006

Filed:

Mar 30, 2004

Appl. No.:

10/813281

Inventors:

David Thomas Ryan - Niskayuna NY, US
Evangelos Trifon Laskaris - Schenectady NY, US
Xianrui Huang - Clifton Park NY, US

Assignee:

General Electric Company - Niskayuna NY

International Classification:

H02K 7/10
H02P 15/00

US Classification:

310 68C, 310 64

Abstract:

A rotating machine comprising a superconductive coil and a temperature sensor operable to provide a signal representative of superconductive coil temperature. The rotating machine may comprise a control system communicatively coupled to the temperature sensor. The control system may be operable to reduce electric current in the superconductive coil when a signal representative of a defined superconducting coil temperature is received from the temperature sensor.

US Patent:

7342757, Mar 11, 2008

Filed:

Jun 28, 2004

Appl. No.:

10/878589

Inventors:

Xianrui Huang - Clifton Park NY, US
Kiruba Haran Sivasubramaniam - Clifton Park NY, US
James William Bray - Niskayuna NY, US
David Thomas Ryan - Niskayuna NY, US

Assignee:

General Electric Company - Niskayuna NY

International Classification:

H02H 5/04
H02H 7/08
H02H 7/00
H02H 9/00
H01H 73/00
H01F 36/00
H01F 1/00
H01F 6/00
H01F 7/00

US Classification:

361 23, 361 19, 361 93, 361115, 323360, 335216

Abstract:

A system and method for protecting a superconductor from a quench condition. A quench protection system is provided to protect the superconductor from damage due to a quench condition. The quench protection system comprises a voltage detector operable to detect voltage across the superconductor. The system also comprises a frequency filter coupled to the voltage detector. The frequency filter is operable to couple voltage signals to a control circuit that are representative of a rise in superconductor voltage caused by a quench condition and to block voltage signals that are not. The system is operable to detect whether a quench condition exists in the superconductor based on the voltage signal received via the frequency filter and to initiate a protective action in response.

US Patent:

7464558, Dec 16, 2008

Filed:

Nov 19, 2003

Appl. No.:

10/718439

Inventors:

Xianrui Huang - Clifton Park NY, US
Paul Shadforth Thompson - Stephentown NY, US
David Thomas Ryan - Niskayuna NY, US
Gregory Alan Lehmann - Florence SC, US
Timothy John Havens - Florence SC, US

Assignee:

General Electric Company - Niskayuna NY

International Classification:

F25B 19/00

US Classification:

62 511, 62 471

Abstract:

A low eddy current cryogen circuit for superconducting magnets including at least a first cooling coil made of an electrically conducting material and having at least one electrical isolator incorporated in the first cooling coil. The electrical isolator is located to inhibit induced eddy current loops due to inductive coupling of the first cooling coil with eddy current inducing field sources.

US Patent:

8033121, Oct 11, 2011

Filed:

Oct 7, 2008

Appl. No.:

12/246800

Inventors:

Xianrui Huang - Clifton Park NY, US
Paul Shadforth Thompson - Stephentown NY, US
David Thomas Ryan - Niskayuna NY, US
Gregory Alan Lehmann - Brookfield WI, US
Timothy John Havens - Florence SC, US

Assignee:

General Electric Company - Schenectady NY

International Classification:

F17C 7/02

US Classification:

62 511

Abstract:

A low eddy current cryogen circuit for superconducting magnets including at least a first cooling coil made of an electrically conducting material and having at least one electrical isolator incorporated in the first cooling coil. The electrical isolator is located to inhibit induced eddy current loops due to inductive coupling of the first cooling coil with eddy current inducing field sources.

US Patent:

20050062473, Mar 24, 2005

Filed:

Sep 24, 2003

Appl. No.:

10/671146

Inventors:

David Ryan - Niskayuna NY, US
Evangelos Laskaris - Niskayuna NY, US
Xianrui Huang - Clifton Park NY, US

International Classification:

G01V003/00

US Classification:

324318000, 324315000

Abstract:

A cryogen free superconducting magnet assembly having a high Tsuperconducting magnet and a thermal reservoir in thermal contact with the high Tsuperconducting magnet. A method of cooling a cryogen free superconducting magnet assembly and an MRI system having cryogen free superconducting magnet assemblies.