Patents by Inventor Timothy R. Fox
Timothy R. Fox 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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Patent number: 9778391Abstract: Radiation scanning systems providing multiple views of an object in different planes and a reconstruction algorithm for reconstructing quasi-three-dimensional images from a limited number of views. A system may include bend magnets to direct accelerated charged particles to multiple targets in different viewing locations. Another system collimates radiation generated by a plurality of radiation sources into multiple beams for scanning an object at multiple angles. The object may be a cargo container, for example. The reconstruction algorithm uses an optimization algorithm and imaging and feasibility models to reconstruct quasi-three-dimensional images from the limited number of views.Type: GrantFiled: March 18, 2014Date of Patent: October 3, 2017Assignee: VAREX IMAGING CORPORATIONInventors: Gongyin Chen, Kevin Holt, Robert E. Drubka, John Stammetti, Michael Z. Duncan, Timothy R. Fox, David Nisius, Martin Hu
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Patent number: 9635748Abstract: The present invention proposes a high speed radiographic system for use with megavolt linear-accelerator pulsed x-ray sources to produce video images of large-area fields. A linear accelerator is positioned above a field of view. X-ray photons are directed through an object of interest traveling and/or colliding within the field of view. A large area scintillator system, either truly continuous or in large continuous adjacent pieces, converts the x-ray photons that pass through the object into visible light, and an arrangement of cameras, focused at that plane, where each camera sees a sub-area of the entire scintillator, and these sub-areas overlap somewhat to cover the entire scintillator. The resulting images generated in each camera are synchronized to produce one contiguous, synchronized stream of images.Type: GrantFiled: March 21, 2013Date of Patent: April 25, 2017Assignee: Varex Imaging CorporationInventor: Timothy R. Fox
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Patent number: 9198276Abstract: A circuit to power an electron source includes a filament transformer comprising a primary side and a secondary side, a high-voltage transformer coupled to the filament transformer and the electron source, and an alternating current (AC) current limiter coupled in series with the primary side or the secondary side of the filament transformer. The AC current limiter includes a diode bridge and a current-limiting device in the diode bridge.Type: GrantFiled: March 15, 2013Date of Patent: November 24, 2015Assignee: Varian Medical Systems, Inc.Inventor: Timothy R. Fox
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Patent number: 9086496Abstract: Methods and systems for scanning objects comprising scanning a portion of an object by a first radiation beam having a first value of a beam characteristic, such as the dose, and detecting the first radiation beam after interaction with the object by a first detector. It is determined whether to change the first value to a second value based, at least in part, on the detected first radiation beam. That portion of the object is then scanned by a second radiation beam having the first value or the second value based on the determination. The second radiation is detected after interacting with the object by a second detector. The second detector may have a second resolution greater than a first resolution of the first detector. The first and second radiation beams may be formed by first and second slots angled with respect to each other.Type: GrantFiled: November 15, 2013Date of Patent: July 21, 2015Assignee: Varian Medical Systems, Inc.Inventors: Daniel Shedlock, Timothy R. Fox, Josh Star-Lack, Richard E. Colbeth, Gary Virshup, James E. Clayton, David T. Nisius
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Publication number: 20150139386Abstract: Methods and systems for scanning objects comprising scanning a portion of an object by a first radiation beam having a first value of a beam characteristic, such as the dose, and detecting the first radiation beam after interaction with the object by a first detector. It is determined whether to change the first value to a second value based, at least in part, on the detected first radiation beam. That portion of the object is then scanned by a second radiation beam having the first value or the second value based on the determination. The second radiation is detected after interacting with the object by a second detector. The second detector may have a second resolution greater than a first resolution of the first detector. The first and second radiation beams may be formed by first and second slots angled with respect to each other.Type: ApplicationFiled: November 15, 2013Publication date: May 21, 2015Applicant: Varian Medical Systems, Inc.Inventors: Josh STAR-LACK, Timothy R. Fox, Daniel Shedlock, Richard E. Colbeth, Gary Virshup, James E. Clayton, David T. Nisius
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Publication number: 20140294147Abstract: Radiation scanning systems providing multiple views of an object in different planes and a reconstruction algorithm for reconstructing quasi-three-dimensional images from a limited number of views. A system may include bend magnets to direct accelerated charged particles to multiple targets in different viewing locations. Another system collimates radiation generated by a plurality of radiation sources into multiple beams for scanning an object at multiple angles. The object may be a cargo container, for example. The reconstruction algorithm uses an optimization algorithm and imaging and feasibility models to reconstruct quasi-three-dimensional images from the limited number of views.Type: ApplicationFiled: March 18, 2014Publication date: October 2, 2014Applicant: Varian Medical Systems, Inc.Inventors: Gongyin CHEN, Kevin Holt, Robert E. Drubka, John Stammetti, Michael Z. Duncan, Timothy R. Fox, David Nisius, Martin Hu
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Publication number: 20140286476Abstract: The present invention proposes a high speed radiographic system for use with megavolt linear-accelerator pulsed x-ray sources to produce video images of large-area fields. A linear accelerator is positioned above a field of view. X-ray photons are directed through an object of interest traveling and/or colliding within the field of view. A large area scintillator system, either truly continuous or in large continuous adjacent pieces, converts the x-ray photons that pass through the object into visible light, and an arrangement of cameras, focused at that plane, where each camera sees a sub-area of the entire scintillator, and these sub-areas overlap somewhat to cover the entire scintillator. The resulting images generated in each camera are synchronized to produce one contiguous, synchronized stream of images.Type: ApplicationFiled: March 21, 2013Publication date: September 25, 2014Applicant: Varian Medical Systems, Inc.Inventor: Timothy R. FOX
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Publication number: 20140265847Abstract: A circuit to power an electron source includes a filament transformer comprising a primary side and a secondary side, a high-voltage transformer coupled to the filament transformer and the electron source, and an alternating current (AC) current limiter coupled in series with the primary side or the secondary side of the filament transformer. The AC current limiter includes a diode bridge and a current-limiting device in the diode bridge.Type: ApplicationFiled: March 15, 2013Publication date: September 18, 2014Applicant: VARIAN MEDICAL SYSTEMS, INC.Inventor: Timothy R. Fox
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Patent number: 8803453Abstract: A method for generating stabilized particle acceleration by a radio-frequency (RF) accelerator is described, comprising operating the accelerator in a warm-up mode during a warm-up time period, without injecting charged particles or without accelerating injected charged particles, and operating the accelerator in a beam-on mode during a beam-on time period after the warm-up time period, to accelerate charged particles injected by the charged particle source. Automatic frequency control to match an expected frequency of the accelerator during the beam-on time period, prior to the start of the beam-on time period, for stability, is also described.Type: GrantFiled: June 22, 2011Date of Patent: August 12, 2014Assignee: Varian Medical Systems, Inc.Inventors: Douglas W. Eaton, Gongyin Chen, Timothy R. Fox
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Patent number: 8565380Abstract: An x-ray detector amplifier operably couples to an analog-to-digital converter interface and a switched voltage clamp is operably disposed there between. By one approach, the switched voltage clamp comprises a switched electrical connection to a constant potential (such as, but not limited to, ground). These teachings will accommodate a control circuit configured to control the switched voltage clamp. This can comprise, for example, controlling the switched voltage clamp in synchronicity with the pulsed x-ray source. These teachings will also accommodate an integrator operably connected between the x-ray detector amplifier and the analog-to-digital converter interface. In such a case, the switched voltage clamp and be controlled to remove substantially any voltage offset contribution of the x-ray detector amplifier (due, for example, to significant temperature excursions) to a signal that is integrated by the aforementioned integrator.Type: GrantFiled: October 5, 2010Date of Patent: October 22, 2013Assignee: Varian Medical Systems, Inc.Inventor: Timothy R. Fox
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Patent number: 8416919Abstract: One facilitates capturing samples as pertain to an object to be imaged by providing N pulsed sampling chains (where N is an integer greater than 1) where these sampling chains are in planes substantially parallel to one another and are substantially equidistant from adjacent others by a given distance. By one approach, the ratio of this given distance to a desired sample interval is approximately an integer that is relatively prime to N. So configured, a complete set of samples of the object can be captured by the sampling chains in a single pass notwithstanding that the object and the sampling chains are moving quickly with respect to one another.Type: GrantFiled: August 20, 2009Date of Patent: April 9, 2013Assignee: Varian Medical Systems, Inc.Inventors: Timothy R. Fox, David T. Nisius
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Publication number: 20120326636Abstract: A method for generating stabilized particle acceleration by a radio-frequency (RF) accelerator is described, comprising operating the accelerator in a warm-up mode during a warm-up time period, without injecting charged particles or without accelerating injected charged particles, and operating the accelerator in a beam-on mode during a beam-on time period after the warm-up time period, to accelerate charged particles injected by the charged particle source. Automatic frequency control to match an expected frequency of the accelerator during the beam-on time period, prior to the start of the beam-on time period, for stability, is also described.Type: ApplicationFiled: June 22, 2011Publication date: December 27, 2012Inventors: Douglas W. Eaton, Gongyin Chen, Timothy R. Fox
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Patent number: 8184769Abstract: At least three radiation-detection views are used to facilitate identifying material as comprises an object being assessed along a beam path relative to that object. This comprises developing a first radiation-detection view (101) as corresponds to the material along the beam path, a second radiation-detection view (102) as corresponds to the material along substantially the beam path, and at least a third radiation-detection view (103) as corresponds to the material along substantially the beam path. At least one of the source spectra and detector spectral responses used for these radiation-detection views are different from one another for each view. One then uses (104) these radiation-detection views to identify the material by, at least in part, differentiating the material from other possible materials.Type: GrantFiled: June 5, 2009Date of Patent: May 22, 2012Assignee: Varian Medical Systems, Inc.Inventors: Timothy R. Fox, Gongyin Chen, Kevin M. Holt, Paul J. Bjorkholm, David T. Nisius
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Publication number: 20120082297Abstract: An x-ray detector amplifier operably couples to an analog-to-digital converter interface and a switched voltage clamp is operably disposed there between. By one approach, the switched voltage clamp comprises a switched electrical connection to a constant potential (such as, but not limited to, ground). These teachings will accommodate a control circuit configured to control the switched voltage clamp. This can comprise, for example, controlling the switched voltage clamp in synchronicity with the pulsed x-ray source. These teachings will also accommodate an integrator operably connected between the x-ray detector amplifier and the analog-to-digital converter interface. In such a case, the switched voltage clamp and be controlled to remove substantially any voltage offset contribution of the x-ray detector amplifier (due, for example, to significant temperature excursions) to a signal that is integrated by the aforementioned integrator.Type: ApplicationFiled: October 5, 2010Publication date: April 5, 2012Applicant: VARIAN MEDICAL SYSTEMS, INC.Inventor: Timothy R. Fox
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Publication number: 20110044493Abstract: One facilitates capturing samples as pertain to an object to be imaged by providing N pulsed sampling chains (where N is an integer greater than 1) where these sampling chains are in planes substantially parallel to one another and are substantially equidistant from adjacent others by a given distance. By one approach, the ratio of this given distance to a desired sample interval is approximately an integer that is relatively prime to N. So configured, a complete set of samples of the object can be captured by the sampling chains in a single pass notwithstanding that the object and the sampling chains are moving quickly with respect to one another.Type: ApplicationFiled: August 20, 2009Publication date: February 24, 2011Applicant: VARIAN MEDICAL SYSTEMS, INC.Inventors: Timothy R. Fox, David T. Nisius
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Publication number: 20100310042Abstract: At least three radiation-detection views are used to facilitate identifying material as comprises an object being assessed along a beam path relative to that object. This comprises developing a first radiation-detection view (101) as corresponds to the material along the beam path, a second radiation-detection view (102) as corresponds to the material along substantially the beam path, and at least a third radiation-detection view (103) as corresponds to the material along substantially the beam path. At least one of the source spectra and detector spectral responses used for these radiation-detection views are different from one another for each view. One then uses (104) these radiation-detection views to identify the material by, at least in part, differentiating the material from other possible materials.Type: ApplicationFiled: June 5, 2009Publication date: December 9, 2010Applicant: Varian Medical Systems, Inc.Inventors: Timothy R. Fox, Gongyin Chen, Kevin M. Holt, Paul J. Bjorkholm, David T. Nisius
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Patent number: 7780352Abstract: A detector array is disposed relative to a radiation source such that radiation from the radiation source over a predetermined time period is substantially similar across the detector array. The detector array includes radiation detectors operatively coupled to detector electronics. The radiation filter material is disposed at least partially between the radiation source and the detector array such that different portions of the detector array are exposed to radiation from the radiation source through either different radiation filter material thicknesses or different radiation filter material compositions during the predetermined time period. So configured, information regarding the radiation such as beam quality information for radiation pulses is collected and used to confirm the quality of the radiation source or to adjust data collected by the radiation system.Type: GrantFiled: March 13, 2008Date of Patent: August 24, 2010Assignee: Varian Medical Systems, Inc.Inventors: Timothy R. Fox, David T. Nisius
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Publication number: 20080226038Abstract: A detector array is disposed relative to a radiation source such that radiation from the radiation source over a predetermined time period is substantially similar across the detector array. The detector array includes radiation detectors operatively coupled to detector electronics. The radiation filter material is disposed at least partially between the radiation source and the detector array such that different portions of the detector array are exposed to radiation from the radiation source through either different radiation filter material thicknesses or different radiation filter material compositions during the predetermined time period. So configured, information regarding the radiation such as beam quality information for radiation pulses is collected and used to confirm the quality of the radiation source or to adjust data collected by the radiation system.Type: ApplicationFiled: March 13, 2008Publication date: September 18, 2008Applicant: Varian Medical Systems Technologies, Inc.Inventors: Timothy R. Fox, David T. Nisius
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Patent number: 6901135Abstract: A method and apparatus are provided for extending a dynamic range of an X-ray imaging system. The method includes the steps of detecting a plurality of X-ray beams, amplifying each of the plurality of detected X-ray beams using a first gain value, amplifying each of the plurality of detected X-ray beams using a second gain value, and forming an X-ray image from the detected X-ray beams amplified by the first gain value and from the detected X-ray beams amplified by the second gain value.Type: GrantFiled: August 28, 2003Date of Patent: May 31, 2005Assignee: Bio-Imaging Research, Inc.Inventors: Timothy R. Fox, David T. Nisius, Michael T. Duncan
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Patent number: 5661774Abstract: The disclosed dual energy baggage scanning assembly includes a CT scanning system, and a conveyor belt for transporting items through the CT scanning system, and an improved power supply for the X-ray source of the CT scanner so that a dual energy beam is provided. The power supply alternately powers the X-ray tube of the scanning system at high and low voltage levels at a predetermined rate and comprises at least one high voltage DC power supply for providing a stable, high DC voltage the X-ray tube; means, including at least one waveform generator, for providing a periodic time varying waveform; and coupling means, including a transformer, for coupling the waveform generator to said DC voltage supply so that the total voltage across the cathode and anode of the tube is periodically changed between the high and low voltage levels at the predetermined rate in response to the periodic time varying waveform provided by the waveform generator.Type: GrantFiled: June 27, 1996Date of Patent: August 26, 1997Assignee: Analogic CorporationInventors: Bernard M. Gordon, Hans Weedon, Iosif Izrailit, Timothy R. Fox, John F. Moore