Patents by Inventor Kwok Tam

Kwok Tam 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: 7257186
    Abstract: An imaging method is disclosed for a multi-slice spiral CT scan. A CT unit is disclosed for carrying out this method. In the method, the filtering may be formed by use of multiple applications of a ramp filter and a masking operation to a projection image in a different sequence. The CT unit may include, for filtering purposes, multiple applications of a ramp filter and a masking operation to a projection image in a different sequence.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: August 14, 2007
    Assignee: Siemens Aktiengesellschaft
    Inventors: Herbert Bruder, Guenter Lauritsch, Karl Stierstorfer, Kwok Tam
  • Publication number: 20070101982
    Abstract: A toy launcher for launching soft darts includes a housing; a motor in the housing; a dart magazine subassembly supported by the housing; a dart magazine rotation subassembly supported by the housing and operated by the motor; and a dart launcher assembly supported by the housing and operated by the motor.
    Type: Application
    Filed: September 30, 2006
    Publication date: May 10, 2007
    Inventors: Kenlip Ong, Kwok Tam, Tai Lee
  • Patent number: 6928137
    Abstract: In a method for generating an image of an examination subject with a tomography-capable X-ray device, particularly a computed tomography device, having a multi-row X-ray detector array, an X-ray radiator that rotates about a system axis and emits a conical x-ray beam, and a positioning device by means of which the subject is positionable relative to the X-ray radiator in different z-positions in a direction parallel to the system axis, the image is reconstructed from the raw data that are generated from the X-ray radiator. Raw data are generated from both a rotation scan and a linear scan. In the linear scan, all transmission values for the image reconstruction are acquired in one continuous linear scanning movement, so that the rotation scan can be picked up while the X-ray radiator is in continuous rotation.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: August 9, 2005
    Assignee: Siemens Aktiengesellschaft
    Inventors: Herbert Bruder, Thomas Flohr, Karl Stierstorfer, Kwok Tam
  • Publication number: 20040264630
    Abstract: An imaging method is for a multi-slice spiral CT scan. An object to be examined is scanned with reference to its absorption behavior by a rotating ray bundle moving in the direction of the axis of rotation, and the measured absorption data are collected. In order to reconstruct volumetric images from the measured data, the latter are filtered and the filtered data are subsequently back-projected in three dimensions in order to generate at least one volumetric image of the object to be examined. The volumetric image represent absorption values, obtained from the data, of the voxels, belonging to the layer of the object to be examined, for the radiation of the ray bundle. A CT unit is for carrying out this method. In the method, the filtering is formed by use of multiple application of a ramp filter R{right arrow over (t)} and a masking operation M to a projection image in a different sequence.
    Type: Application
    Filed: October 17, 2003
    Publication date: December 30, 2004
    Inventors: Herbert Bruder, Guenter Lauritsch, Karl Stierstorfer, Kwok Tam
  • Publication number: 20040141581
    Abstract: In a method for generating an image of an examination subject with a tomography-capable X-ray device, particularly a computed tomography device, having a multi-row X-ray detector array, an X-ray radiator that rotates about a system axis and emits a conical x-ray beam, and a positioning device by means of which the subject is positionable relative to the X-ray radiator in different z-positions in a direction parallel to the system axis, the image is reconstructed from the raw data that are generated from the X-ray radiator. Raw data are generated from both a rotation scan and a linear scan. In the linear scan, all transmission values for the image reconstruction are acquired in one continuous linear scanning movement, so that the rotation scan can be picked up while the X-ray radiator is in continuous rotation.
    Type: Application
    Filed: September 26, 2003
    Publication date: July 22, 2004
    Inventors: Herbert Bruder, Thomas Flohr, Karl Stierstorfer, Kwok Tam
  • Patent number: 6763081
    Abstract: Improved image reconstruction methods for cone beam ROI (region of interest) imaging of long objects with an area detector using a two or more circular scans and a connecting line scan, wherein essentially the entire detector area is utilized for acquiring cone beam data for all source positions.
    Type: Grant
    Filed: October 2, 2002
    Date of Patent: July 13, 2004
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Publication number: 20040066876
    Abstract: Improved image reconstruction methods for cone beam ROI (region of interest) imaging of long objects with an area detector using a two or more circular scans and a connecting line scan, wherein essentially the entire detector area is utilized for acquiring cone beam data for all source positions.
    Type: Application
    Filed: October 2, 2002
    Publication date: April 8, 2004
    Inventor: Kwok Tam
  • Patent number: 6574297
    Abstract: A system and method for accurately reconstructing an image of a ROI (region of interest) within a long object by removing components associated with data contamination. In one aspect, an image reconstruction method comprises collecting a set of image data along a spiral scan path of a ROI (region of interest) portion of an object, identifying contaminated data within the collected set of image data, the contaminated data corresponding to image data associated with an object outside the ROI, and reconstructing an image of the ROI using the set of image data less the contaminated data.
    Type: Grant
    Filed: October 30, 2001
    Date of Patent: June 3, 2003
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Publication number: 20030081715
    Abstract: A system and method for accurately reconstructing an image of a ROI (region of interest) within a long object by removing components associated with data contamination. In one aspect, an image reconstruction method comprises collecting a set of image data along a spiral scan path of a ROI (region of interest) portion of an object, identifying contaminated data within the collected set of image data, the contaminated data corresponding to image data associated with an object outside the ROI, and reconstructing an image of the ROI using the set of image data less the contaminated data.
    Type: Application
    Filed: October 30, 2001
    Publication date: May 1, 2003
    Inventor: Kwok Tam
  • Patent number: 6459756
    Abstract: A system and method for 3D image reconstruction in a spiral scan cone beam computed tomography (CT) imaging system that allows the pitch of spiral scan projection to be reduced by a factor of 1/n (where n=3, 5, 7, 9, etc), thereby increasing the x-ray dosage to obtain a higher S/N (signal-to-noise) ratio, while achieving efficient use of a fixed-size detector. In addition, an image reconstruction protocol computes a correction factor for integration planes that intersect the reduced-pitch spiral path (which surrounds a ROI) at only M<n locations within an angular range that is determined, e.g., for M=1 planes, based on mask boundaries applied to the cone beam data. Despite the reduced pitch, the M<n integration planes do not provide increased flux (in contrast to other integration planes that intersect the object and scan path in M∃n locations).
    Type: Grant
    Filed: October 30, 2001
    Date of Patent: October 1, 2002
    Assignee: Siemens Corporate Research, Inc.
    Inventors: Kwok Tam, Günter Lauritsch, Herbert Bruder
  • Patent number: 6333960
    Abstract: A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of an ROI in an object, wherein data is calculated on a plurality of line segments L formed in cone beam projection data acquired on a detector at a plurality of source positions. The endpoints of the line segments L formed in the data acquired at each of the source positions is determined by a data combination mask having its bounds formed by cone beam projection onto the plane of the detector of portions of the source scan path that are above and below the source position that acquired the cone beam data in which the data for the line segments L are being calculated.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: December 25, 2001
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Patent number: 6330298
    Abstract: A method and apparatus for three dimensional (3D) computerized tomographic (CT) imaging of an object, wherein image reconstruction processing is applied to a plurality of sets of 2D cone beam projection data, each set being acquired on a 2D detector at a corresponding plurality of scan path source positions. A first image reconstruction processing step comprises applying a mask to each set of the projection data so that data inside the boundaries of each mask form a corresponding plurality of masked 2D data sets. Next, the data inside each masked 2D data set is processed along line segments formed in the masked 2D data set, and having their endpoints determined by the mask boundaries, to develop a first 2D estimate of data determined from a given set of the 2D cone beam projection data.
    Type: Grant
    Filed: October 17, 2000
    Date of Patent: December 11, 2001
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Patent number: 6324245
    Abstract: A method and apparatus for three dimensional (3D) computerized tomographic (CT) imaging of an object, wherein image reconstruction processing is applied to a plurality of sets of 2D cone beam projection data, each set being acquired on a 2D detector at a corresponding plurality of scan path source positions. A first image reconstruction processing step comprises applying a mask to each set of the projection data so that data inside the boundaries of each mask form a corresponding plurality of masked 2D data sets. Next, the data inside each masked 2D data set is processed along line segments formed in the masked 2D data set, and having their endpoints determined by the mask boundaries, to develop a first 2D estimate of data determined from a given set of the 2D cone beam projection data. The next step comprises identifying portions of said line segments which is not used to develop said first 2D estimate of data, to develop 2D correction data for each of the first 2D estimates of data.
    Type: Grant
    Filed: October 17, 2000
    Date of Patent: November 27, 2001
    Assignee: Siemens Corporation Research, Inc.
    Inventor: Kwok Tam
  • Patent number: 6292525
    Abstract: A method and apparatus for three dimensional (3D) computerized tomography (CT) imaging wherein a reconstructed image is developed by calculating along line segments L formed in cone beam data. The endpoints of which are determined by a data combination mask. At source positions near the top and bottom of the ROI, the mask is divided into separate portions using a horizontal line, each having a set of line segments L formed therein. The reconstruction data is calculated by performing one-dimensional (1D) convolving operations of the data along the line segments L, the 1D convolving operation developing an additive contribution to a new projection image. Finally, the new projection image is backprojected into a 3D space, thereby reconstructing a 3D image of the ROI in the object.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: September 18, 2001
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Patent number: 6233303
    Abstract: A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of an ROI in an object, wherein a reconstructed image is developed by calculating reconstruction data along a plurality of line segments L formed in cone beam data acquired on a detector at a plurality of source positions about the ROI. The endpoints of the line segments L formed in the cone beam data acquired at each of the source positions is determined by a data combination mask which is applied to the cone beam data. When acquiring cone beam data near the top or bottom edges of the ROI, a radiation blocking element is operated for blocking radiation directed toward the ROI, so that only that portion of the detector is exposed to radiation.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: May 15, 2001
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Patent number: 6130930
    Abstract: A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of an ROI in an object, wherein data is calculated on a plurality of line segments L formed in cone beam projection data acquired on a detector at a plurality of source positions. The endpoints of the line segments L formed in the data acquired at each of the source positions is determined by a data combination mask having its bounds formed by cone beam projection onto the plane of the detector of portions of the source scan path that are above and below the source position that acquired the cone beam data in which the data for the line segments L are being calculated.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: October 10, 2000
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Patent number: 6078638
    Abstract: A method and apparatus for three dimensional (3D) computerized tomographic (CT) imaging of a region-of-interest (ROI) in an object, wherein image reconstruction processing is applied to a plurality of sets of pixels of 2D image data, each set being acquired on a pixelated 2D detector. The image reconstruction processing comprises filtering each of the acquired 2D image data sets for developing a corresponding plurality of filtered 2D images; and then 3D backprojecting the filtered 2D images into a common 3D space, thereby reconstructing in the 3D space a 3D image of the ROI in the object. In the present invention the filtering step comprises dividing the pixels of each set of the acquired 2D image data sets into first and second groups, and separately filtering the image data of each group to develop for each group it's own contribution to the corresponding filtered 2D image.
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: June 20, 2000
    Assignee: Siemens Corporate Research, Inc.
    Inventors: Frank Sauer, Kwok Tam, Bruce Ladendorf
  • Patent number: 6018561
    Abstract: A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomographic (CT) imaging of a region-of-interest (ROI) in an object, wherein image reconstruction processing is applied to a plurality of sets of 2D cone beam projection data, each set being acquired on a 2D detector at a corresponding plurality of scan path source positions. A first image reconstruction processing step comprises applying a mask to each set of the projection data so that data inside the boundaries of each mask form a corresponding plurality of masked 2D data sets. The next step comprises ramp filtering of each masked 2D data set along a plurality of parallel lines formed therein, to generate a corresponding plurality of filtered 2D data sets. Each filtered 2D data set is a calculation of a first estimate of Radon derivative data determined from a given set of the 2D cone beam projection data.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: January 25, 2000
    Assignee: Siemens Corporate Research, Inc.
    Inventor: Kwok Tam
  • Patent number: 6009142
    Abstract: A method and apparatus of operating a CT imaging apparatus having a cone beam radiation source and a 2D detector arrangement, for exactly reconstructing an image of a 3D region of interest (ROI) in an object. Measurement data acquired by the 2D detector is processed to develop sub-sets of Radon data. Each of the sub-sets of Radon data is targeted for reconstructing a corresponding local 2D ROI in a 2D parallel projection of the object. Accordingly, after a sub-set of Radon data is completely developed, it is subjected to a first inversion processing step for developing the corresponding local 2D ROI. Multiple ones of the local ROIs are then grouped together and subjected to a second inversion processing step to develop an image reconstruction of a part of the 3D ROI in the object.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: December 28, 1999
    Assignee: Siemens Corporate Research, Inc.
    Inventors: Frank Sauer, Supun Samarasekera, Kwok Tam
  • Patent number: 5970111
    Abstract: A computed tomographic imaging apparatus performs three-dimensional (3D) image reconstruction of a region of interest of an object using a plurality of processors for processing successive sets of cone beam measurement data that are acquired by scanning about the object with a cone beam radiation source and an area detector. A central memory has stored therein a plurality of subsets of pre-calculated image processing information, and the plurality of processors are responsive to a given sequence of successive ones of the subsets of pre-calculated image processing information for converting the cone beam measurement data to Radon derivative data on a plurality of Radon .phi.-planes.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: October 19, 1999
    Assignee: Siemens Corporate Research, Inc.
    Inventors: Supun Samarasekera, Frank Sauer, Kwok Tam, Ali R. Bani-Hashemi