Patents by Inventor John M. Siegel

John M. Siegel 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: 6409700
    Abstract: Blood is withdrawn from a vein by a double lumen catheter that has an elongated tube with unitary outer walls. A longitudinal planar septum divides the interior of the tube into an inlet lumen and a longer return lumen. The inlet lumen extends from a proximal end of the tube to an end terminating in a distally forward facing aperture. The return lumen extends contiguously with the inlet lumen from the proximal end of the tube to an end terminating in a distally forward facing aperture spaced in the longitudinal direction distally forward of the inlet lumen aperture. A diverting structure extends from an outer wall of the return lumen distally forward of the aperture of the inlet lumen. The diverting structure diverts flow of treated fluid discharged from the return lumen away from the distally forward facing aperture of the inlet lumen. The blood withdrawn via the catheter is circulated for treatment in a blood purification system.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: June 25, 2002
    Assignee: CFD Research Corporation
    Inventors: John M. Siegel, Jr., Vinod B. Makhijani, Ming Lei, Jagannath Raghavan
  • Publication number: 20020032629
    Abstract: A method of screening equities is disclosed. The method includes the steps of ranking a plurality of equity parameters to normalize each equity parameter with respect to each other equity parameter. User preferences respecting the weight to be given equity parameters of interest are received and the ranked equity parameters of interest are weighted based upon the received user preferences to assign each equity a score. A scored equity appropriate for the user preferences may then be selected. A system for screening equities is also disclosed.
    Type: Application
    Filed: April 26, 2001
    Publication date: March 14, 2002
    Inventors: John M. Siegel, Fyodor N. Golos
  • Patent number: 5521502
    Abstract: A flow differentiation scheme is disclosed for magnetic resonance imaging (MRI) of fluid flow in regions of turbulent flow. The flow differentiation scheme comprises the steps of (1) obtaining a first magnetic resonance (MR) image of the region, (2) obtaining a second MR image of the same region with an imaging parameter or imaging sequence altered, and (3) logically differentiating the first and second images with respect to flow to create a difference image. The process may be enhanced by superimposing one of the original images, upon an image that has been flow differentiated. As a result, a substantial amount of the static signal is suppressed producing superior angiograms of diseased and undiseased blood vessels. Additionally, the scheme can be used to image any fluid flow in any body or thing.
    Type: Grant
    Filed: April 25, 1994
    Date of Patent: May 28, 1996
    Assignee: Georgia Tech Research Corporation
    Inventors: John M. Siegel, Jr., David N. Ku
  • Patent number: 5438992
    Abstract: Magnetic resonance imaging of a blood vessel exhibits flow artifacts, or signal loss, around a constriction (26) due to turbulent fluid flow. Signal loss in a region (27) prior to the constricted region (26) is primarily caused by convective acceleration, and this signal loss is substantially eliminated by performing an acceleration compensation process. Signal loss in a region (32) situated after the constriction (26) is primarily caused by velocity fluctuations, and this signal loss is cured by an imaging process which does not rely on the phase of the electromagnetic excitation signal(s) for spatial localization. Examples of imaging processes for minimizing signal loss due to turbulence include a projection reconstruction process (34) and a two dimensional slice selection process (56). Further, the two dimensional slice selection process (56) may be used for generating instantaneous velocities of fluid flowing through a fluid channel.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: August 8, 1995
    Assignee: Georgia Tech Research Corporation
    Inventors: John M. Siegel, Jr., David N. Ku, John N. Oshinski, Roderic I. Pettigrew