Patents by Inventor Hammond Glenn Reynolds

Hammond Glenn Reynolds has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6323646
    Abstract: A technique is provided for generating images on an MRI system in which errors due to gradient pulses are compensated. The errors are identified in advance, such as in a calibration sequence performed on the MRI system. Receiver phase adjustment and logical gradient error values are derived from the identified error values. The calibration sequence may be a modified version of the MRI imaging sequence used to produce the images. The correction values may be based upon corrections at the center of k-space. The technique is particularly useful in compensating for effects of eddy currents in pulse sequences employing high slew rate gradient pulses, such as diffusion weighted echo planar imaging sequences.
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: November 27, 2001
    Assignee: General Electric Company
    Inventors: Xiaohong Zhou, Joseph K. Maier, Steven J. Huff, Hammond Glenn Reynolds
  • Patent number: 5864233
    Abstract: An eddy current correction method is provided for use in an MR system disposed to generate difflusion-weighted echo planar images by employing a bipolar diffusion-weighting gradient as well as the nominal components in an echo planar imaging pulse sequence. The correction method comprises the steps of deriving eddy current parameters (i.e., amplitude and time constant) associated with each eddy-current-induced magnetic field component caused by the diffusion-weighting gradient, and generating a set of correction terms, each of the correction terms being a function of the parameters. The method includes the further steps of modifyg a set of ideal echo planar imaging gradients and the receiver phase and frequency to respectively offset the eddy current induced magnetic field gradient and the spatially independent B.sub.0 -magnetic field. The modification occurs in two stages.
    Type: Grant
    Filed: February 22, 1997
    Date of Patent: January 26, 1999
    Assignee: General Electric Company
    Inventors: Xiaohong Zhou, Joseph K. Maier, Hammond Glenn Reynolds