Daniel J Schaefer

US Patent:

6882153, Apr 19, 2005

Filed:

Apr 7, 2004

Appl. No.:

10/709016

Inventors:

Robert Michael Vavrek - Waukesha WI, US
Graeme Colin McKinnon - Hartland WI, US
Daniel Joseph Schaefer - Waukesha WI, US

Assignee:

GE Medical Systems Global Technology Company, LLC - Waukesha WI

International Classification:

G01V003/00

US Classification:

324322, 600410

Abstract:

A method for decreasing gradient field pulse sequence duration for a magnetic resonance imaging system, the method comprising: establishing an allowable gradient field strength for an axis of a plurality of axes for a field of view; applying a weighting factor associated with each axis of the plurality of axes; establishing a slew rate responsive to a selected axis of the plurality of axes that exhibits a largest gradient field strength in light of the weighting factor and the field of view; and operating the plurality of axes at the largest gradient field strength.

US Patent:

7081752, Jul 25, 2006

Filed:

Apr 4, 2003

Appl. No.:

10/249390

Inventors:

Timothy W. Skloss - Waukesha WI, US
Dewain A. Purgill - Waukesha WI, US
Roman I. Dachniwskyj - Pewaukee WI, US
Daniel J. Schaefer - Waukesha WI, US
Steven C. Davis - Oconomowoc WI, US
Daniel J. Weyers - Wauwatosa WI, US

Assignee:

General Electric Company - Schenectady NY

International Classification:

G01V 3/00

US Classification:

324318

Abstract:

A system and method including an apparatus for use in electrically loading RF coils of an MRI system is disclosed. The apparatus includes a polymer interdispersed with an electrically conductive additive such that the apparatus provides the necessary electrical loading of the RF coils for testing and calibration of the MRI system but is free of liquid. Furthermore, the apparatus is capable of providing the requisite electrical load in high magnet magnetic fields without introducing image distortion as a result of standing waves within the apparatus.

US Patent:

20040075434, Apr 22, 2004

Filed:

Oct 16, 2002

Appl. No.:

10/065422

Inventors:

Robert Vavrek - Waukesha WI, US
Graeme McKinnon - Hartland WI, US
Daniel Schaefer - Waukesha WI, US

International Classification:

G01V003/00

US Classification:

324/318000, 324/309000

Abstract:

A gradient coil assembly for a magnetic resonance imaging system comprising: a first gradient coil configured to generate a first gradient field in a first field of view; a second gradient coil configured to generate a second gradient field orthogonal to the first gradient field in a second field of view; and a third gradient coil configured to generate a third gradient field orthogonal to the first gradient field and the second gradient field in a plurality of fields of view.

US Patent:

20050262819, Dec 1, 2005

Filed:

Sep 29, 2004

Appl. No.:

10/953875

Inventors:

Steve Weber - Germantown WI, US
Daniel Schaefer - Port Washington WI, US

International Classification:

A01D069/00

US Classification:

056010800

Abstract:

A control assembly for use with a vehicle having a power take off and a gear shift device. The assembly can include a modular housing and a control that can be movable between a default position and an override position. The assembly can include a terminal block and a control circuit electrically connected to the terminal block and coupled to the modular housing. The assembly can further include an indicator electrically connected to the control circuit and coupled to the modular housing to indicate whether the control circuit is operating according to a default condition or an override condition.

US Patent:

20050274098, Dec 15, 2005

Filed:

Jun 1, 2004

Appl. No.:

10/858569

Inventors:

Steve Weber - Germantown WI, US
Daniel Schaefer - Port Washington WI, US

International Classification:

A01D075/28

US Classification:

05601020R

Abstract:

Override assembly apparatus and method for use with a lawnmower including a control circuit coupled to a first housing. The control circuit can prevent the lawnmower from cutting while the lawnmower is moving in a reverse direction. The override assembly can include a second housing separate from the first housing, a user-manipulatable control, and a terminal block. The override assembly can include an override circuit that can operate in a first state in which the control circuit is enabled and a second state in which the control circuit is disabled in response to the user-manipulatable control.

US Patent:

52931269, Mar 8, 1994

Filed:

Nov 9, 1992

Appl. No.:

7/973444

Inventors:

Daniel J. Schaefer - Waukesha WI

Assignee:

General Electric Company - Milwaukee WI

International Classification:

G01R 3320

US Classification:

324318

Abstract:

A local coil assembly includes an RF coil disposed inside a cylindrical form and a pair of z-axis gradient coils wound around the outside of the cylindrical form. First and second pairs of gradient coils are mounted on opposite sides and extend radially outward from the cylindrical form. These pairs of gradient coils produce a gradient field perpendicular to the z-axis with minimal effect on the operation of the RF coil.

US Patent:

47125608, Dec 15, 1987

Filed:

Aug 9, 1985

Appl. No.:

6/764092

Inventors:

Daniel J. Schaefer - Waukesha WI
Kenneth W. Belt - Fort Atkinson WI

Assignee:

General Electric Company - Milwaukee WI

International Classification:

A61B 505

US Classification:

128653

Abstract:

An apparatus and method are disclosed which provide signals corresponding to physiological motion of an imaging slice in an MR system for use in synchronizing acquisition of MR data with movement of the slice. The signals are generated by initiating an incident signal of a frequency. omega. which interacts with the imaging slice and returns a reflected signal of a frequency. omega. By mixing the incident and reflected signal, a baseband signal is generated which is indicative of changes in the phase and magnitude relationships between the signals. Because changes in the phase and magnitude relationships between the signals are related in an approximately linear manner to movement of the imaging slice, the baseband signal provides an indication of movement of the imaging slice of sufficient quality to serve as an accurate triggering signal to synchronize acquistion of MR data with movement of the imaging slice.

US Patent:

51072157, Apr 21, 1992

Filed:

Jun 25, 1990

Appl. No.:

7/543609

Inventors:

Daniel J. Schaefer - Waukesha WI
Hammond G. Reynolds - Milwaukee WI
Joseph K. Maier - Milwaukee WI

Assignee:

General Electric - Milwaukee WI

International Classification:

G01V 300

US Classification:

324314

Abstract:

An NMR imaging system includes a prescan procedure in which the RF transmit power level is calibrated to produce an optimal, uniform RF field. Pulse sequences are conducted at a series of RF power levels and from the resulting acquired NMR data the power level which produces the most uniform signal across the extent of the subject being imaged is determined.