Robert Steven Perlmutter

US Patent:

48765090, Oct 24, 1989

Filed:

Nov 3, 1987

Appl. No.:

7/116437

Inventors:

Robert J. Perlmutter - Palo Alto CA

Assignee:

Resonex, Inc. - Sunnyvale CA

International Classification:

G01R 3320

US Classification:

324309

Abstract:

An improved image restoration technique for an MRI method is provided where after the corrected location of image points is determined, an improved interpolation technique is used in determining the intensity value of that image point utilizing the surrounding pixels, e. g. , 4 or 16. The interpolation technique provides for a uniform noise variance by using a weighted average interpolation technique with the added constraint that the sum of the squares of the interpolation weighting functions is substantially equal to a constant. The resulting image may be sharpened by a hybrid convolution technique which separately processes border regions.

US Patent:

47010061, Oct 20, 1987

Filed:

Feb 20, 1985

Appl. No.:

6/703521

Inventors:

Robert J. Perlmutter - Palo Alto CA

Assignee:

Stanford University - Stanford CA

International Classification:

G03H 108

US Classification:

350 366

Abstract:

A hologram is formed of an object by calculating a two dimensional complex field distribution for a diffraction pattern of the object, and then modulating a first coherent light beam with amplitude and phase values of the two-dimensional complex field distribution as the first coherent light beam is scanned across a recording medium. A second reference coherent light beam is scanned across the recording medium and intersects the first modulated coherent light beam in the recording medium as the two beams are scanned. A reflection hologram is synthesized in the recording medium by directing the two beams from opposite sides of the film recording medium.

US Patent:

52143830, May 25, 1993

Filed:

Oct 16, 1991

Appl. No.:

7/778305

Inventors:

Robert J. Perlmutter - Palo Alto CA
Brian P. Wilfley - Los Altos CA
Rick Motamedi - Sunnyvale CA
John Moberly - Mountain View CA

Assignee:

Resonex, Inc. - Sunnyvale CA

International Classification:

G01R 3320

US Classification:

324313

Abstract:

External field compensation is provided for MRI apparatus which is in a magnetically noisy environment such as that caused by nearby subway trains. By means of a magnetometer type sensor, the external field fluctuation is sensed and after being adjusted for the filtering effect of the magnet structure of the MRI device itself, the master oscillator of the MRI device is adjusted to compensate for the external field fluctuation. Alternatively the current of the magnet coil is adjusted.