Patents by Inventor Amar C. Dhanantwari

Amar C. Dhanantwari 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: 6719696
    Abstract: An adaptive multidimensional beamformer having near-instantaneous convergence for ultrasound imaging systems deploying multidimensional sensor arrays is disclosed. In a first step, the multidimensional beamformer is decomposed into sub-apertures. Each sub-aperture is then again decomposed into two coherent subsets of circular and/or line array beamformers in different coordinate directions of the multidimensional array. Implementation of the multidimensional beamformer according to the present invention provides the basis for a 3D ultrasound imaging system according to the present invention comprising a compact multidimensional sensor array and a compact processing unit that is field deployable and generates high resolution three-dimensional images in real time. It is also possible to capture four-dimensional images, the fourth dimension being time and the resulting images forming a video image of a volume of a moving organ.
    Type: Grant
    Filed: October 21, 2002
    Date of Patent: April 13, 2004
    Assignee: Her Majesty the Queen in right of Canada as represented by the Minister of National Defence
    Inventors: Stergios Stergiopoulos, Amar C. Dhanantwari
  • Publication number: 20030065262
    Abstract: An adaptive multidimensional beamformer having near-instantaneous convergence for ultrasound imaging systems deploying multidimensional sensor arrays is disclosed. In a first step, the multidimensional beamformer is decomposed into sub-apertures. Each sub-aperture is then again decomposed into two coherent subsets of circular and/or line array beamformers in different coordinate directions of the multidimensional array. Implementation of the multidimensional beamformer according to the present invention provides the basis for a 3D ultrasound imaging system according to the present invention comprising a compact multidimensional sensor array and a compact processing unit that is field deployable and generates high resolution three-dimensional images in real time. It is also possible to capture four-dimensional images, the fourth dimension being time and the resulting images forming a video image of a volume of a moving organ.
    Type: Application
    Filed: October 21, 2002
    Publication date: April 3, 2003
    Inventors: Stergios Stergiopoulos, Amar C. Dhanantwari
  • Patent number: 6535570
    Abstract: A method of tracking organ motion and removing motion artifacts in conventional computer tomography scans is disclosed. Sensor time series indicative of projection measurement data of the object are correlated using a software spatial overlap correlator method in order to obtain a sinogram indicative of organ motion. The software spatial overlap correlator method is based on the fact that the image sampling process of a computer tomography scanner is periodical, therefore, image samples taken at a time t and at a time t+T are taken from identical spatial locations. The sinogram is then processed using a retrospective gating method or a coherent sinogram synthesis method in order to correct the image data for motion effects. This method for motion correction is software based and, therefore, can be easily implemented in existing computer tomography systems without major hardware modification.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: March 18, 2003
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence of Her Majesty's Canadian Government
    Inventors: Stergios Stergiopoulos, Amar C. Dhanantwari
  • Patent number: 6520918
    Abstract: A method and a device for measuring systolic and diastolic blood pressure and heart rate in an environment comprising extreme levels of noise and vibrations is disclosed. Blood pressure signals corresponding to the heart beat are detected using a first acoustic sensor placed on a patient near an artery. A second acoustic transducer is placed on the patient away from the artery for detecting noise and vibrations. Pressure is applied to the artery forcing the artery to close. The pressure is then reduced and while reducing the pressure the acoustic signals detected by the first and second acoustic sensor as well as a signal indicative of the pressure applied to the artery are provided to a processing unit. The signal of the first acoustic sensor is then processed using an adaptive interferer canceller algorithm with the signal of the second acoustic sensor as interferer.
    Type: Grant
    Filed: November 24, 2000
    Date of Patent: February 18, 2003
    Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of National Defence
    Inventors: Stergios Stergiopoulos, Amar C. Dhanantwari
  • Patent number: 6482160
    Abstract: An adaptive multidimensional beamformer having near-instantaneous convergence for ultrasound imaging systems deploying multidimensional sensor arrays is disclosed. In a first step, the multidimensional beamformer is decomposed into sub-apertures. Each sub-aperture is then again decomposed into two coherent subsets of circular and/or line array beamformers in different coordinate directions of the multidimensional array. Implementation of the multidimensional beamformer according to the present invention provides the basis for a 3D ultrasound imaging system according to the present invention comprising a compact multidimensional sensor array and a compact processing unit that is field deployable and generates high resolution three-dimensional images in real time. It is also possible to capture four-dimensional images, the fourth dimension being time and the resulting images forming a video image of a volume of a moving organ.
    Type: Grant
    Filed: November 24, 2000
    Date of Patent: November 19, 2002
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence
    Inventors: Stergios Stergiopoulos, Amar C. Dhanantwari
  • Publication number: 20020025017
    Abstract: A method of tracking organ motion and removing motion artifacts in conventional computer tomography scans is disclosed. Sensor time series indicative of projection measurement data of the object are correlated using a software spatial overlap correlator method in order to obtain a sinogram indicative of organ motion. The software spatial overlap correlator method is based on the fact that the image sampling process of a computer tomography scanner is periodical, therefore, image samples taken at a time t and at a time t+T are taken from identical spatial locations. The sinogram is then processed using a retrospective gating method or a coherent sinogram synthesis method in order to correct the image data for motion effects. This method for motion correction is software based and, therefore, can be easily implemented in existing computer tomography systems without major hardware modification.
    Type: Application
    Filed: February 2, 2001
    Publication date: February 28, 2002
    Inventors: Stergios Stergiopoulos, Amar C. Dhanantwari
  • Patent number: 6236705
    Abstract: A method of tracking organ motion and removing motion artifacts in X-ray computer tomography scans is disclosed. An object is irradiated by two sources such that the object is irradiated from a same location at two different time instances. Projection measurement data are detected by a receiving sensor array. The projection measurement data of the object irradiated from the same location at the two different time instances are correlated using a spatial overlap correlator method in order to obtain data indicative of organ motion. The projection measurement data and the data indicative of organ motion are then processed using an adaptive processing method to remove artifacts due to organ motion.
    Type: Grant
    Filed: June 17, 1999
    Date of Patent: May 22, 2001
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence
    Inventors: Stergios Stergiopoulos, Amar C. Dhanantwari