Patents by Inventor Ha Wong
Ha Wong 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).
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Publication number: 20200234939Abstract: Certain configurations of mass spectrometer components are described herein that comprise one or more mass spectrometer programmable elements. In some instances, the mass spectrometer programmable element can be configured as an electrode that can function independently of any underlying substrate or component. Ion guides, lenses, ion switches, mass analyzers and other components of a mass spectrometer are described which comprise one or more mass spectrometer programmable elements.Type: ApplicationFiled: December 12, 2019Publication date: July 23, 2020Inventors: Tak Shun Cheung, Chui Ha Wong, William Fisher, Hamid Badiei
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Publication number: 20140218025Abstract: A transverse volume magnetic resonance (MR) coil includes a cylindrical geometry of electrical conductors configured for generating a B1 field comprising nth mode spatial harmonics along a first transverse axis in a transverse plane orthogonal to a central axis of the coil, while being uniform along a second transverse axis orthogonal to the first transverse axis in the transverse plane, where n is an integer ranging from 1 or greater. The coil may be included with other coils in an array coil. The coil may be utilized to detect geometric echoes resulting from excitation of an MR sample.Type: ApplicationFiled: February 1, 2013Publication date: August 7, 2014Applicant: AGILENT TECHNOLOGIES, INC.Inventor: WAI HA WONG
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Patent number: 8766636Abstract: According to one aspect, a magnetic resonance imaging (MRI) scanner includes a short birdcage (e.g. millipede) distributed-capacitance radio-frequency (RF) coil formed from one or more patterned planar conductive foils. The transverse extent (e.g. diameter) of the coil is at least a factor of 3, for example about a factor of 10, larger than the longitudinal (z-axis) extent of the coil. Flux-return gaps may be provided between the sample measurement volume defined by the coil and RF shields adjacent to the sample measurement volume, to confine the RF magnetic field to the sample measurement volume. Exemplary coils described herein are particularly suited for very high-frequency MRI measurements.Type: GrantFiled: December 15, 2010Date of Patent: July 1, 2014Assignee: Agilent Technologies, Inc.Inventor: Wai Ha Wong
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Publication number: 20130082709Abstract: A magnetic resonance imaging (MRI) apparatus comprises a plurality of cylindrical electromagnetic coils arranged in a coaxial configuration around a sample region. The coils are used to capture resonance signals from a sample at different times according to a geometric echo effect. The measurements can then be combined to produce an MRI signal.Type: ApplicationFiled: August 13, 2012Publication date: April 4, 2013Applicant: AGILENT TECHNOLOGIES, INC.Inventors: Alan R. RATH, Wai Ha WONG, Weston A. ANDERSON
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Publication number: 20120153955Abstract: According to one aspect, a magnetic resonance imaging (MRI) scanner includes a short birdcage (e.g. millipede) distributed-capacitance radio-frequency (RF) coil formed from one or more patterned planar conductive foils. The transverse extent (e.g. diameter) of the coil is at least a factor of 3, for example about a factor of 10, larger than the longitudinal (z-axis) extent of the coil. Flux-return gaps may be provided between the sample measurement volume defined by the coil and RF shields adjacent to the sample measurement volume, to confine the RF magnetic field to the sample measurement volume. Exemplary coils described herein are particularly suited for very high-frequency MRI measurements.Type: ApplicationFiled: December 15, 2010Publication date: June 21, 2012Applicant: AGILENT TECHNOLOGIES, INC.Inventor: Wai Ha Wong
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Patent number: 8125226Abstract: A low pass RF ladder coil, which is named as a millipede surface coil, comprises a first and a second conductor end strips running parallel to each other. A set of rung elements are placed between them, alternate rung elements are connected to the first and second strip respectively. The number and spacing of the rung elements are sufficient for resonating the coil at the desired imaging frequency. This millipede surface coil may have 100 or more rung elements. Fixed and variable capacitors are provided for separately tuning and matching the first and second mode resonant frequencies, and for coupling and impedance matching the two modes to external circuits. An active detuning is provided that detunes the ladder coil when a separate RF coil is transmitting.Type: GrantFiled: July 2, 2009Date of Patent: February 28, 2012Assignee: Agilent Technologies, Inc.Inventors: Wai Ha Wong, Subramaniam Sukumar
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Publication number: 20110001479Abstract: A low pass RF ladder coil, which is named as a millipede surface coil, comprises a first and a second conductor end strips running parallel to each other. A set of rung elements are placed between them, alternate rung elements are connected to the first and second strip respectively. The number and spacing of the rung elements are sufficient for resonating the coil at the desired imaging frequency. This millipede surface coil may have 100 or more rung elements. Fixed and variable capacitors are provided for separately tuning and matching the first and second mode resonant frequencies, and for coupling and impedance matching the two modes to external circuits. An active detuning is provided that detunes the ladder coil when a separate RF coil is transmitting.Type: ApplicationFiled: July 2, 2009Publication date: January 6, 2011Inventors: Wai Ha Wong, Subramaniam Sukumar
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Patent number: 7791339Abstract: A multimode resonator resonating at two or more frequencies is operated at cryogenic temperatures and composed of a superconducting material or a normal metal with a superconducting section serving as a RF superconducting switch. The multimode resonator is coupled to a NMR spectrometer and a RF switch power source, wherein its one frequency is selected to correspond to the operating frequency of the NMR spectrometer and at least a second frequency is tuned to a frequency of RF switch power source, unrelated to the spectrometer frequency, therefore power at this frequency does not perturb the operation of the spectrometer. When activated, the RF switch power source induces a current sufficient to approach or exceeds the critical current in one or more sections of the superconducting material of the multimode resonator, thereby increasing its resistance and reducing the Q factor of the multimode resonator.Type: GrantFiled: September 7, 2007Date of Patent: September 7, 2010Assignee: Varian, Inc.Inventors: Wai Ha Wong, Richard Stacy Withers, Weston A. Anderson
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Publication number: 20090302846Abstract: A multimode resonator resonating at two or more frequencies is operated at cryogenic temperatures and composed of a superconducting material or a normal metal with a superconducting section serving as a RF superconducting switch. The multimode resonator is coupled to a NMR spectrometer and a RF switch power source, wherein its one frequency is selected to correspond to the operating frequency of the NMR spectrometer and at least a second frequency is tuned to a frequency of RF switch power source, unrelated to the spectrometer frequency, therefore power at this frequency does not perturb the operation of the spectrometer. When activated, the RF switch power source induces a current sufficient to approach or exceeds the critical current in one or more sections of the superconducting material of the multimode resonator, thereby increasing its resistance and reducing the Q factor of the multimode resonator.Type: ApplicationFiled: September 7, 2007Publication date: December 10, 2009Inventors: Wai Ha Wong, Richard Stacy Withers, Weston A. Anderson
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Patent number: 7501828Abstract: A switchable birdcage coil functioning as a transmitter coil and a separate RF surface coil functioning as the receiver coil are utilize in NMR and MRI apparatus. To prevent the switchable birdcage coil from absorbing energy by coupling to the receiver coil or by absorbing power from the RF field produced by the precessing nuclear spins, one or more of the reactive elements of the birdcage coil are switched from a normal reactive impedance state to a high impedance state. The high impedance state is formed by switchably combining the reactive element with a complementary reactive element thereby forming parallel resonant high impedance circuit that is tuned to resonate at the NMR frequency.Type: GrantFiled: December 19, 2007Date of Patent: March 10, 2009Assignee: Varian, Inc.Inventors: Wai Ha Wong, Alan R. Rath, Steven A. Suddarth
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Publication number: 20070168297Abstract: A system and method of conducting secure business-to-business transactions by exchanging commitments and secure transaction tokens, where two levels of verification stringency are used for increasing the efficiency while maintaining sufficient security. The commitments are verified by a more stringent standard, such as PKI operations while the secure transaction tokens are verified by a more efficient but less stringent standard such as hash operations. The transaction token both represents a monetary value and provides an instruction on how to treat the monetary value it represents. In other words, the token has dual attributes: value and type. Particular embodiments based on the well-known PayWord specification are disclosed.Type: ApplicationFiled: January 18, 2006Publication date: July 19, 2007Inventors: Siu Cheng, Ha Wong, Kam Lau
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Publication number: 20070150744Abstract: Embodiments include a method and a system of authenticating a client when the client logs in a servicing. According to one embodiment, a first authentication code and a second authentication code is submitted from the client to the servicing server. The second authentication code includes a secure token of a reversal secure token chain with a hash function and an index of the secure token in the reversal secure token chain. The first authentication code is then verified at the servicing server. The secure token is also verified at the servicing server by comparing a hash value of the secure token with a previously acquired secure token or a root of the reversal secure token chain. If the first authentication code and the second authentication code are associated, the login is confirmed.Type: ApplicationFiled: December 22, 2005Publication date: June 28, 2007Inventors: Siu Cheng, Ha Wong, Kam Lau
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Patent number: 6980000Abstract: NMR coils are formed from transmission line comprising a tuned LC circuit determined substantially from the distributed capacitance and inductance of the transmission line operated in common mode. Introduction of gaps staggered between opposite conductors of 2-conductor transmission line contribute a desired distributed capacitance with reduced effective inductance to sustain resonant behavior at higher frequency than achievable with conventionally tuned coils and with relaxation of dimensional constraints as the resonant half wavelength approaches coil dimensions.Type: GrantFiled: April 29, 2003Date of Patent: December 27, 2005Assignee: Varian, Inc.Inventors: Wai Ha Wong, Jimmy Leung, Alexander Funk, Knut Mehr
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Patent number: 6876200Abstract: A high resolution NMR probe having two or more resonators, an inner resonator which is closely coupled to a sample and is used to stimulate and receive a response from one nuclear species, and an outer resonator to induce transitions in another nuclear species, wherein the resonators may be provided with cooling capability and may be made of superconducting material, and wherein the inner resonator may be a saddle coil or a birdcage coil with capability of being tuned, and wherein the outer resonator may be one or more spiral wound saddle coil.Type: GrantFiled: March 31, 2003Date of Patent: April 5, 2005Assignee: Varian, Inc.Inventors: Weston Anderson, Wai Ha Wong, James Finnigan
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Publication number: 20040217761Abstract: NMR coils are formed from transmission line comprising a tuned LC circuit determined substantially from the distributed capacitance and inductance of the transmission line operated in common mode. Introduction of gaps staggered between opposite conductors of 2-conductor transmission line contribute a desired distributed capacitance with reduced effective inductance to sustain resonant behavior at higher frequency than achievable with conventionally tuned coils and with relaxation of dimensional constraints as the resonant half wavelength approaches coil dimensions.Type: ApplicationFiled: April 29, 2003Publication date: November 4, 2004Inventors: Wai Ha Wong, Jimmy Leung, Alexander Funk, Knut Mehr
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Patent number: 6806713Abstract: A multimode RF probe for use with a sample oriented at an angle &thgr; to a polarizing field B0 produces a resultant RF magnetic field exhibiting enhanced coupling to the sample. The multiple modes are furnished by a quadrature coil, or a solenoidal coil in combination with either a saddle coil or quadrature coil.Type: GrantFiled: October 15, 2002Date of Patent: October 19, 2004Assignee: Varian, Inc.Inventor: Wai Ha Wong
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Publication number: 20040189304Abstract: A high resolution NMR probe having two or more resonators, an inner resonator which is closely coupled to a sample and is used to stimulate and receive a response from one nuclear species, and an outer resonator to induce transitions in another nuclear species, wherein the resonators may be provided with cooling capability and may be made of superconducting material, and wherein the inner resonator may be a saddle coil or a birdcage coil with capability of being tuned, and wherein the outer resonator may be one or more spiral wound saddle coil.Type: ApplicationFiled: March 31, 2003Publication date: September 30, 2004Inventors: Weston Anderson, Wai Ha Wong, James Finnigan
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Patent number: 6794868Abstract: A method of optimizing effects of a shim system on static magnetic field in an imaging system or liquid spectroscopy system, wherein for each cell of a probe disposed within the magnetic field, the resonant frequency is obtained without any current being supplied to any shim coil, then for each cell, the resonant frequency thereof is obtained by a current being supplied to one shim without any current being supplied to the other shims, and a factor is obtained for each cell due only to the magnetic field produced by current supplied to the one shim, and the resulting difference divided by the current supplied to the shim is obtained for each cell for each separate shim current, from the data an equation is derived relating the field at each cell to the individual shim current. For the case when the number of cells is equal to or less than the number of shim coils, this equation is inverted to give the shim current values to produce the same field at all cells.Type: GrantFiled: June 20, 2003Date of Patent: September 21, 2004Assignee: Varian, Inc.Inventors: Wai Ha Wong, Weston A. Anderson
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Patent number: 6735851Abstract: Superconducting birdcage coil with low-pass and high-pass coil configurations are formed by using strips each with an elongated sapphire substrate with a layer of a high temperature superconductor (HTS) material grown in a wavy pattern over its entire length on one of its main surfaces. A low-pass coil is formed with a pair of ring elements made of an electrically conductive metal and a plurality of such strips arranged parallel to one another and interconnecting these ring elements at junctions which are spaced peripherally along each of the rings. At each of the junctions, the ring element and the HTS layer form a capacitance. A high-pass coil is formed by a plurality of such strips each with electrodes of the HTS material also grown at two end positions separated from each other on the other main surface of its sapphire substrates. These strips are arranged parallel to each other and sequentially around a central axis, each lying in a plane which includes the center axis.Type: GrantFiled: January 8, 2002Date of Patent: May 18, 2004Assignee: Varian, Inc.Inventors: Marco A. Romo, Wai Ha Wong
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Publication number: 20040070398Abstract: A multimode RF probe for use with a sample oriented at an angle &thgr; to a polarizing field B0 produces a resultant RF magnetic field exhibiting enhanced coupling to the sample. The multiple modes are furnished by a quadrature coil, or a solenoidal coil in combination with either a saddle coil or quadrature coil.Type: ApplicationFiled: October 15, 2002Publication date: April 15, 2004Inventor: Wai Ha Wong