Abstract: MRI signals from two species such as fat and water are separated by repeatedly applying a steady state free precession (SSFP) sequence to an object with the phase of each RF excitation pulse in a sequence being increased by 2?n/N radians on each repetition, where acquisition number n ranges from 1 to N. Alternatively, center frequency for each scan is incremented compared with the first scan center frequency. Images are reconstructed from the acquired signals and summed. Slowing varying phase due to sources other than chemical shift can be removed. Species signals are separated based on phase (sign) of the summed image signals.
Type:
Grant
Filed:
September 13, 2005
Date of Patent:
March 6, 2007
Assignee:
The Board of Trustees of the Leland Stanford Junior Univeristy
Abstract: A measurement tool connects to an automatic inspection machine for identifying and measuring microscopic dimensions such as area, diameter, height and line width of defects and lines of a photographic mask. An operator draws a rough region of interest around a feature and the tool automatically identifies the feature and calculates its dimensions. For features less than one micron in size, the size of light photons interferes with measurement, so a non-linear polynomial calibration curve is developed for each machine. Features of known sizes are measured on a production machine to produce a calibration curve for each type of defect or line. Features of unknown sizes are measured on the same machine and the measured size in pixels are calibrated using the calibration curve to return a more accurate reading in microns.
Abstract: A swiveling electrical connector is described which includes a male assembly and a female assembly having a receptacle for receiving the male assembly. A locking mechanism coupled to the female assembly locks the male and female assemblies together when the male assembly is inserted into the female assembly thereby providing electrical contact between conductors in the male assembly and corresponding conductors in the female assembly. The locking mechanism is operable to facilitate a quick release of the male assembly from the female assembly. The male and female assemblies rotate relative to each other when locked together.
Type:
Grant
Filed:
April 18, 1996
Date of Patent:
September 8, 1998
Inventors:
Kim Purington, Jeffrey Powers, Robert J. Wright