Patents by Inventor Dan Xu

Dan Xu 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: 7826587
    Abstract: A CT system includes a gantry, an x-ray source, a generator configured to energize the x-ray source to a first kVp and to a second kVp, a detector, and a controller. The controller is configured energize the x-ray source to the first kVp for a first time period, subsequently energize the x-ray source to the second kVp for a second time period, integrate data for a first integration period that includes a portion of a steady-state period of the x-ray source at the first kVp, integrate data for a second integration period that includes a portion of a steady-state period of the x-ray source at the second kVp, compare a signal-to-noise ratio (SNR) during the first integration period (SNRH) and the second integration period (SNRL), adjust an operating parameter of the CT system to optimize an SNRH with SNRL, and generate an image using the integrated data.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: November 2, 2010
    Assignee: General Electric Company
    Inventors: David Allen Langan, John Eric Tkaczyk, James Walter LeBlanc, Colin R. Wilson, Xiaoye Wu, Dan Xu, Thomas Matthew Benson, Jed Douglas Pack
  • Publication number: 20100264926
    Abstract: Techniques for designing RF pulses may be configured to produce improved magnitude profiles of the resulting magnetization by relaxing the phase constraint and optimizing the phase profiles. In one embodiment, a spinor-based, optimal control, optimal phase technique may be used to design arbitrary-tip-angle (e.g., large and small tip angle) RF pulses (both parallel transmission and single channel). In another embodiment, small tip angle RF pulses (both parallel transmission and single channel) may be designed using a small-tip-angle (STA) pulse design without phase constraint that is formulated as a parameter optimization problem.
    Type: Application
    Filed: April 16, 2009
    Publication date: October 21, 2010
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Dan Xu, Kevin F. King, Graeme C. McKinnon
  • Patent number: 7737690
    Abstract: A system and method are provided for adjusting RF pulses and gradient waveforms to reduce B1 field magnitude in MR imaging sequences. When an RF pulse is presented which has a high amplitude segment that would exceed a maximum B1 magnitude, the system and method provided herein can apply a variable slew rate design technique. A slew rate of at least one gradient waveform can be varied to reduce a B1 field magnitude during transmission of the high amplitude segment of the RF pulse. By controlling the slew rate of gradient waveforms for non-Cartesian k-space trajectories according to a calculated maximum allowable slew rate function, embodiments of the system and method can, in effect, reduce gradient amplitude.
    Type: Grant
    Filed: May 18, 2007
    Date of Patent: June 15, 2010
    Assignee: General Electric Company
    Inventors: Dan Xu, Kevin F. King
  • Patent number: 7705594
    Abstract: A system and method are provided for designing RF pulses which have improved magnetization profiles. By utilizing an optimal control approach as an alternative to, or in combination with, non-iterative approximations, RF pulses generated by the system and method described herein will exhibit less deviation from that of “ideal” Bloch solutions. Consequently, the magnetization profiles produced by the RF pulses generated by the system and method described herein will be closer to the desired profiles. In addition, limitations of non-iterative approximations, such as maximum tip angle limits and linearity constraints, can be avoided.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: April 27, 2010
    Assignees: General Electric Company, University of Illinois at Urbana Champaign
    Inventors: Dan Xu, Kevin F. King, Zhi-Pei Liang
  • Publication number: 20100086084
    Abstract: An OFDM demodulator which does not require a reference signal for synchronization of carriers and can reduce influence of phase rotation by a propagation path when carrier synchronization is made. The OFDM demodulator performs Fourier transform plural times in 2 or more different operation ranges for the same OFDM symbol, calculates phases of sub carriers from the plural-time results of the Fourier transform, compares the calculated phases for each of the plural-time results of the Fourier transform and detects an error in frequency of reproduction carrier from the compared results.
    Type: Application
    Filed: October 7, 2009
    Publication date: April 8, 2010
    Inventors: Koichi ARATANI, Hirotake ISHII, Dan XU
  • Publication number: 20100075886
    Abstract: An alkaline cleaning composition for use in aqueous medium comprising nanoparticles or a nanoparticles precursor and a polymeric nanoparticle-protease compatibilizer.
    Type: Application
    Filed: September 3, 2009
    Publication date: March 25, 2010
    Inventors: Anju Deepali Massey Brooker, Weihua LAN, Dan XU, Alberto MARTINEZ-BECARES, David William YORK
  • Publication number: 20100075884
    Abstract: An alkaline cleaning composition for use in a wash liquor comprising nanoparticles or a nanoparticles precursor and a nanoparticle compatible protease.
    Type: Application
    Filed: September 3, 2009
    Publication date: March 25, 2010
    Inventors: Anju Deepali Massey Brooker, Weihua Lan, Dan Xu, Alberto Martinez-Becares, David William York, Philip Frank Souter
  • Publication number: 20100075885
    Abstract: An alkaline cleaning composition for use in aqueous medium comprising nanoparticles or a nanoparticles precursor and a polymeric nanoparticle stabilizer.
    Type: Application
    Filed: September 3, 2009
    Publication date: March 25, 2010
    Inventors: ANJU DEEPALI MASSEY BROOKER, WEIHUA LAN, DAN XU, ALBERTO MARTINEZ-BECARES, DAVID WILLIAM YORK
  • Publication number: 20100046359
    Abstract: In a wireless communication system based on an OFDM access system, when forgetting averaging channel estimation is performed, there occurs a phase difference between a present channel estimated value and a past estimated value due to a change of FFT operation timing at a reception side. The error of the channel estimated value caused by the phase difference is corrected. A synchronization catching/tracking unit to determine an operation timing of an FFT from a received signal is provided, and an FFT operation timing difference acquisition section to grasp a change of the operation timing of the FFT generated by the synchronization catching/tracking unit is provided.
    Type: Application
    Filed: June 29, 2009
    Publication date: February 25, 2010
    Inventors: Dan Xu, Mikio Kuwahara, Yuji Ishida, Masanori Taira
  • Publication number: 20090264134
    Abstract: In a radio communication system wherein radio frequencies for communicating with a radio terminal are different in radio base stations, a table in which positional information, information on the frequency used for transmission/reception to/from the terminal, and a decision condition in a handoff operation are stored as to each base station is prepared in a base station controller beforehand. When the positional information is received from the radio terminal, the base station controller selects the base station being a handoff candidate, on the basis of the positional information of the radio terminal, the positional information of each base station and the decision condition of the handoff operation with reference to the table, and it transmits a handoff request message which contains the information on the frequency of the base station being the handoff candidate, to the radio terminal through the base station communicating with the radio terminal.
    Type: Application
    Filed: April 14, 2009
    Publication date: October 22, 2009
    Inventors: Dan Xu, Yuichiro Katsu, Tsutomu Uchida, Shiro Mazawa
  • Patent number: 7592809
    Abstract: Variable-density (VD), sequentially-interleaved sampling of k-space coupled with the acquisition of reference frames of data is carried out to improve spatiotemporal resolution, image quality, and signal-to-noise ratio (SNR) of dynamic images. In one example, ktSENSE is implemented with a non-static regularization image, such as that provided by RIGR or similar technique, to acquire and reconstruct dynamic images. The integration of ktSENSE and RIGR, for example, provides dynamic images with higher spatiotemporal resolution and lower image artifacts compared to dynamic images acquired and reconstructed using ktSENSE alone.
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: September 22, 2009
    Assignee: General Electric Company
    Inventors: Kevin F. King, Dan Xu, Zhi-Pei Liang
  • Publication number: 20090082242
    Abstract: A method of cleaning a soiled load in an automatic dishwasher comprising the step of contacting the load with a phosphate free wash liquor comprising exfoliated nanoclay, the liquor having a pH of from about 9 to about 12 and an ionic strength of from about 0.001 to about 0.02 moles/l.
    Type: Application
    Filed: September 17, 2008
    Publication date: March 26, 2009
    Inventors: Anju Deepali Massey Brooker, Alberto Martinez-Becares, David William York, Dan Xu
  • Publication number: 20090082243
    Abstract: A particle having a size of from about 50 to about 1,000 ?m comprising a low-shear exfoliable nanoclay, the nanoclay having a primary particle size of from about 10 to about 300 nm. The invention also includes detergents comprising the particle and a process for making the particle.
    Type: Application
    Filed: September 17, 2008
    Publication date: March 26, 2009
    Inventors: Anju Deepali Massey Brooker, Alberto Martinez-Becares, David William York, Dan Xu, Gillian Margaret Hardy
  • Patent number: 7466131
    Abstract: A system and method are provided for designing RF pulses for multi-channel and/or multi-dimensional spatially-selective applications using a linear approximation. Embodiments of the system and method may use a generalized linear-class large tip angle approximation to design RF pulses for multi-channel and parallel transmission. Further, some of these approximations allow for the design of arbitrarily large flip angles, irregularly-shaped flip angle profiles, or arbitrary initial magnetization values. Embodiments of the system and method may also provide for the design of k-space trajectories which aid in maintaining assumptions of the various linear class approximations.
    Type: Grant
    Filed: April 20, 2007
    Date of Patent: December 16, 2008
    Assignees: General Electric Company, The Board of Trustees of the University of Illinois
    Inventors: Dan Xu, Kevin F. King, Zhi-Pei Liang
  • Publication number: 20080284439
    Abstract: A system and method are provided for adjusting RF pulses and gradient waveforms to reduce B1 field magnitude in MR imaging sequences. When an RF pulse is presented which has a high amplitude segment that would exceed a maximum B1 magnitude, the system and method provided herein can apply a variable slew rate design technique. A slew rate of at least one gradient waveform can be varied to reduce a B1 field magnitude during transmission of the high amplitude segment of the RF pulse. By controlling the slew rate of gradient waveforms for non-Cartesian k-space trajectories according to a calculated maximum allowable slew rate function, embodiments of the system and method can, in effect, reduce gradient amplitude.
    Type: Application
    Filed: May 18, 2007
    Publication date: November 20, 2008
    Inventors: Dan Xu, Kevin F. King
  • Publication number: 20080238425
    Abstract: A system and method are provided for designing RF pulses which have improved magnetization profiles. By utilizing an optimal control approach as an alternative to, or in combination with, non-iterative approximations, RF pulses generated by the system and method described herein will exhibit less deviation from that of “ideal” Bloch solutions. Consequently, the magnetization profiles produced by the RF pulses generated by the system and method described herein will be closer to the desired profiles. In addition, limitations of non-iterative approximations, such as maximum tip angle limits and linearity constraints, can be avoided.
    Type: Application
    Filed: March 30, 2007
    Publication date: October 2, 2008
    Inventors: Dan Xu, Kevin F. King, Zhi-Pei Liang