Patents by Inventor Lee A. Christel
Lee A. Christel 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: 20020058282Abstract: An apparatus for determining a threshold value (e.g., a threshold cycle number or a time value) in a nucleic acid amplification reaction comprises a detection mechanism for measuring, at a plurality of different times during the amplification reaction, at least one signal whose intensity is related to the quantity of a nucleic acid sequence being amplified in the reaction. A controller in communication with the detection mechanism is programmed to store signal values defining a growth curve for the nucleic acid sequence, determine a derivative of the growth curve, and calculate a cycle number or time value associated with a characteristic of the derivative.Type: ApplicationFiled: December 19, 2001Publication date: May 16, 2002Applicant: CepheidInventors: William A. McMillan, Lee A. Christel, David A. Borkholder, Steven J. Young
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Publication number: 20020055167Abstract: A device for separating an analyte from a fluid sample comprises a cartridge having a sample port and a first flow path extending from the sample port. A microfluidic chip is positioned in the first flow path. The microfluidic chip includes an extraction chamber having an array of microstructures for capturing the analyte from the sample as the sample flows through the extraction chamber and for subsequently releasing the captured analyte into an elution fluid as the elution fluid flows through the extraction chamber. Each of the microstructures has an aspect ratio of at least 2:1. The cartridge also includes a second flow path for eluting the captured analyte from the microfluidic chip, the second flow path diverging from the first flow path after passing through the chip. At least one flow controller directs the sample into the first flow path and the eluted analyte into the second flow path.Type: ApplicationFiled: November 7, 2001Publication date: May 9, 2002Applicant: CepheidInventors: Farzad Pourahmadi, William A. McMillan, Jesus Ching, Ronald Chang, Lee A. Christel, Gregory T.A. Kovacs, M. Allen Northrup, Kurt E. Petersen
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Publication number: 20020045246Abstract: A device for use with an ultrasonic transducer to lyse components of a fluid sample comprises a cartridge having a lysing chamber, an inlet port in fluid communication with the lysing chamber, and an outlet port for exit of the sample from the lysing chamber. The inlet and outlet ports are positioned to permit flow of the sample through the lysing chamber, and the chamber contains at least one solid phase for capturing the sample components to be lysed as the sample flows through the chamber. The lysing chamber is defined by at least one wall having an external surface for contacting the transducer to effect the transfer of ultrasonic energy to the chamber.Type: ApplicationFiled: November 7, 2001Publication date: April 18, 2002Applicant: CepheidInventors: William A. McMillan, Kurt E. Petersen, Lee A. Christel, Ronald Chang, Farzad Pourahmadi, Jesus Ching, Gregory T.A. Kovacs, M. Allen Northrup
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Publication number: 20020042125Abstract: An analyte is separated from a fluid sample by introducing the sample into a cartridge having a sample port and a first flow path extending from the sample port. The first flow path includes an extraction chamber containing a solid support for capturing the analyte from the sample. The cartridge has a second flow path for eluting the captured analyte from the extraction chamber, the second flow diverging from the first flow path after passing through the extraction chamber. The sample is forced to flow through the extraction chamber and into a waste chamber, thereby capturing the analyte with the solid support as the sample flows through the extraction chamber. The captured analyte is then eluted from the extraction chamber by forcing an elution fluid to flow through the extraction chamber and along the second flow path.Type: ApplicationFiled: November 7, 2001Publication date: April 11, 2002Applicant: CepheidInventors: Kurt E. Petersen, William A. McMillan, Lee A. Christel, Ronald Chang, Farzad Pourahmadi, Jesus Ching, Gregory T.A. Kovacs, M. Allen Northrup
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Patent number: 6369893Abstract: An apparatus for thermally controlling and optically interrogating a reaction mixture includes a vessel [2] having a chamber [10] for holding the mixture. The apparatus also includes a heat-exchanging module [37] having a pair of opposing thermal plates [34A, 34B] for receiving the vessel [2] between them and for heating/and or cooling the mixture contained in the vessel. The module [37] also includes optical excitation and detection assemblies [46,48] positioned to optically interrogate the mixture. The excitation assembly [46] includes multiple light sources [100] and a set of filters for sequentially illuminating labeled analytes in the mixture with excitation beams in multiple excitation wavelength ranges. The detection assembly [48] includes multiple detectors [102] and a second set of filters for detecting light emitted from the chamber [10] in multiple emission wavelength ranges.Type: GrantFiled: May 19, 1999Date of Patent: April 9, 2002Assignee: CepheidInventors: Lee A. Christel, M. Allen Northrup, Kurt E. Petersen, William A. McMillan, Gregory T. A. Kovacs, Steven J. Young, Ronald Chang, Douglas B. Dority, Raymond T. Hebert, Gregory J. Kintz
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Publication number: 20020039783Abstract: A device for lysing components (e.g., cells, spores, or microorganisms) of a fluid sample comprises a cartridge having a lysing chamber for receiving the sample and having at least one solid phase in the lysing chamber for capturing the sample components to be lysed. An ultrasonic transducer is coupled to a wall of the lysing chamber to transfer ultrasonic energy to the captured sample components.Type: ApplicationFiled: November 7, 2001Publication date: April 4, 2002Applicant: CepheidInventors: William A. McMillan, Kurt E. Petersen, Lee A. Christel, Ronald Chang, Farzad Pourahmadi, Jesus Ching, Gregory T.A. Kovacs, M. Allen Northrup
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Publication number: 20020034746Abstract: A computer program product for determining a threshold value (e.g., a threshold cycle number or time value) in a nucleic acid amplification reaction tangibly embodies instructions readable by a machine to perform the steps of deriving a growth curve from measurements of a signal whose intensity is related to a quantity of nucleic acid sequence being amplified in the reaction, calculating a derivative of the growth curve, identifying a characteristic of the derivative, and determining a threshold value associated with the characteristic of the derivative. The method provides for highly reproducible threshold values that are independent of noise or background signal in the amplification reaction. Embodiments of a computer program product for determining a starting quantity of a nucleic acid sequence in a test sample are also provided.Type: ApplicationFiled: March 14, 2001Publication date: March 21, 2002Applicant: CepheidInventors: William A. McMillan, Lee A. Christel, David A. Borkholder, Steven J. Young
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Publication number: 20020034745Abstract: An apparatus for determining a threshold value (e.g., a threshold cycle number or a time value) in a nucleic acid amplification reaction comprises a detection mechanism for measuring, at a plurality of different times during the amplification reaction, at least one signal whose intensity is related to the quantity of a nucleic acid sequence being amplified in the reaction. The apparatus also includes a controller in communication with the detection mechanism. The controller is programmed to perform the steps of deriving a growth curve from the measurements of the signal; calculating a derivative of the growth curve; identifying a characteristic of the derivative; and determining a threshold value associated with the characteristic of the derivative. Embodiments of an apparatus for determining a starting quantity of a nucleic acid sequence in a test sample are also provided.Type: ApplicationFiled: March 14, 2001Publication date: March 21, 2002Applicant: CepheidInventors: William A. McMillan, Lee A. Christel, David A. Borkholder, Steven J. Young
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Publication number: 20020031768Abstract: A method for determining an unknown starting quantity of a target nucleic acid sequence in a test sample comprises the steps of amplifying the unknown starting quantity of the target nucleic acid sequence in the test sample and known starting quantities of a calibration nucleic acid sequence in respective calibration samples; and determining a respective threshold value for each of the nucleic acid sequences using a derivative of a growth curve derived for the sequence. The starting quantity of the target nucleic acid sequence in the test sample is determined using the threshold value determined for the target sequence and a calibration curve derived from the threshold values determined for the known starting quantities of the calibration nucleic acid sequences. The invention also provides methods for determining a starting quantity of a nucleic acid sequence in a sample using quantitative internal controls or using internal standards.Type: ApplicationFiled: March 14, 2001Publication date: March 14, 2002Applicant: CepheidInventors: William A. McMillan, Lee A. Christel, David A. Borkholder, Steven J. Young
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Patent number: 6140143Abstract: A method of micromachining silicon to form relatively thick boss areas and relatively thin flexure areas. The method includes the provision of a deep diffusion of n-type dopant atoms in the vicinity of the desired thick boss structures on a p-type silicon substrate. A layer having a thickness equal to the desired thickness of a flexure area is epitaxially grown of n-type doped silicon over the previously doped p-type substrate. Finally, the p-type doped silicon is etched away by a suitable etchant leaving relatively thick boss areas joined by relatively thin flexure areas.Type: GrantFiled: February 10, 1992Date of Patent: October 31, 2000Assignee: Lucas Novasensor Inc.Inventors: Lee A. Christel, Theodore J. Vermeulen
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Patent number: 5231301Abstract: An electromechanical sensor is provided which comprises an n-type semiconductor region which defines a flexible member surrounded by a thicker base portion; at least one piezoresistor formed in the semiconductor region; an n+ region formed in the thicker base portion; a first insulative layer which overlays the piezoresistor and which extends at least from the piezoresistor to the first n+ doped region; a guard layer which overlays at least a portion of the first insulative layer such that the guard layer overlays the piezoresistor and extends at least from the piezoresistor to a point adjacent to the n+ region; and a first bias contact which electrically interconnects the n+ region and the guard layer.Type: GrantFiled: October 2, 1991Date of Patent: July 27, 1993Assignee: Lucas NovaSensorInventors: Kurt E. Peterson, Lee A. Christel
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Patent number: 4963500Abstract: Method of determining contaminants in a semiconductor processing apparatus in which a high purity, high carrier lifetime semiconductor test wafer is processed and the degradation of its carrier lifetime is determined.Type: GrantFiled: February 2, 1988Date of Patent: October 16, 1990Assignee: Sera Solar CorporationInventors: George W. Cogan, Gary E. Miner, Lee A. Christel, James F. Gibbons
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Patent number: 4824489Abstract: A method for processing solar cells, and particularly thin solar cells is disclosed. The method contemplates processing the front surface of the cell on a wafer of normal thickness. A transparent substrate is adhered to the front of the processed cell. The bulk semiconductor layer is then thinned to the desired thickness. An amorphous doped semiconductor material is applied to the back surface of the thinned wafer and exposed to pulsed laser energy having a duration and intensity long enough to melt the amorphous material, but short enough to prevent thermal damage to the bondline. A back surface dielectric, backside contact mask and back surface reflector metal complete the cell.Type: GrantFiled: February 2, 1988Date of Patent: April 25, 1989Assignee: Sera Solar CorporationInventors: George W. Cogan, Lee A. Christel, J. Thomas Merchant, James F. Gibbons
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Patent number: 4612408Abstract: An interconnected array of solar cell or photodiode devices is formed by a method which includes the steps of forming on one major surface of a semiconductor wafer a plurality of said devices, forming grooves in said one major surface extending partway into said substrate between adjacent said devices, forming an oxide layer on selected portions of said one major surface and on the surfaces of said grooves, filling the grooves with an insulating material, forming metal interconnects between adjacent devices extending over said grooves and insulating material, attaching said one major surface to an insulating support, and severing through the wafer into the grooves from the other major surface to separate adjacent devices while leaving the metal interconnects.Type: GrantFiled: October 22, 1984Date of Patent: September 16, 1986Assignee: Sera Solar CorporationInventors: Garret R. Moddel, Lee A. Christel, James F. Gibbons