Patents by Inventor Charles N. Stewart

Charles N. Stewart 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: 8447385
    Abstract: A microwave handheld radiometer for measuring subsurface tissue temperature of a subject includes a microwave antenna disposed relative to a handheld radiometer housing and adapted to electromagnetically couple to a skin surface of a subject, a circulator having a first circulator input and a second circulator input, wherein the first circulator input is electrically coupled to said antenna via a microwave feedline. A switch is electrically disposed between the antenna and an microwave feedline, said switch having a calibrate state and a measure state. A noise source, electrically coupled to the circulator, is being configured to provide a first source of thermal noise at a first temperature and a second source of thermal noise at a second temperature, wherein the noise source is switched between the first source and second source upon external command wherein a detector provides an output wherein surface temperature effects are corrected for the sub-surface measurement.
    Type: Grant
    Filed: July 28, 2010
    Date of Patent: May 21, 2013
    Assignee: Welch Allyn, Inc.
    Inventors: Fred Sterzer, Daniel D. Mawhinney, Laleh Rabieirad, David E. Quinn, John A. Lane, Matthew D. Mullin, Charles N. Stewart
  • Publication number: 20120029359
    Abstract: A microwave handheld radiometer for measuring subsurface tissue temperature of a subject includes a microwave antenna disposed relative to a handheld radiometer housing and adapted to electromagnetically couple to a skin surface of a subject, a circulator having a first circulator input and a second circulator input, wherein the first circulator input is electrically coupled to said antenna via a microwave feedline. A switch is electrically disposed between the antenna and an microwave feedline, said switch having a calibrate state and a measure state. A noise source, electrically coupled to the circulator, is being configured to provide a first source of thermal noise at a first temperature and a second source of thermal noise at a second temperature, wherein the noise source is switched between the first source and second source upon external command wherein a detector provides an output wherein surface temperature effects are corrected for in the sub-surface measurement.
    Type: Application
    Filed: July 28, 2010
    Publication date: February 2, 2012
    Applicant: Welch Allyn, Inc.
    Inventors: Fred Sterzer, Daniel D. Mawhinney, Laleh Rabieirad, David E. Quinn, John A. Lane, Matthew D. Mullin, Charles N. Stewart
  • Publication number: 20090290719
    Abstract: A stethoscopic assembly includes a stethoscope having a chest piece interconnected to at least one earpiece, the chest piece having an acoustical sensor enabling patient sounds to be heard through the at least one earpiece. A microprocessor connected to the acoustical sensor of the stethoscope includes a buffer wherein sound data picked up from the microphone is stored in volatile memory for a predetermined time period. At least one user operable switch connected to the microprocessor enables selective capture of sound data for storage and playback, such as through at least one speaker. In some versions the acoustical sensor is releasable from the chest piece.
    Type: Application
    Filed: May 22, 2008
    Publication date: November 26, 2009
    Inventors: Andrew J. Kugler, Charles N. Stewart, John A. Lane, Alisa Jean Robinson, Suzanne Abate Gunter, Udaya Patnaik, Michael D. Smith, Lucas C. McCann, Ashley Elizabeth Tudor, Isabel P. O'Meara
  • Patent number: 7458934
    Abstract: An LED for use with a medical diagnostic instrument having an adapter disposed between an instrument head and a hand-grippable handle, the LED being removably attachable in relation to the adapter in order to permit selective replacement of the LED, as needed. The LED is situated in order to provide mechanical and electrical interface with at least one of the adapter and the instrument, thereby enabling the adapter and the LED to convert the illumination source of the instrument selectively between an incandescent light source and the LED. The adapter matches a polarity between the LED and a power supply that is specifically intended for powering an incandescent light source.
    Type: Grant
    Filed: May 17, 2007
    Date of Patent: December 2, 2008
    Assignee: Welch Allyn, Inc.
    Inventors: Chris R. Roberts, Corinn C. Fahrenkrug, Allan I. Krauter, Shawn A. Briggman, Michael A. Pasik, Peter J. Davis, John R. Strom, Charles N. Stewart, Jon R. Salvati, Robert L. Vivenzio
  • Patent number: 7276025
    Abstract: An adapter for permitting a medical diagnostic instrument having an illumination source including at least one LED (light emitting diode) to be used with a power supply normally configured for use with a diagnostic instrument having at least one incandescent lamp as an illumination source. The adapter includes circuitry for compensating LED specific characteristics for permitting the power supply to be used with the LED.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: October 2, 2007
    Assignee: Welch Allyn, Inc.
    Inventors: Chris R. Roberts, Corinn C. Fahrenkrug, Allan I. Krauter, Shawn A. Briggman, Michael A. Pasik, Peter J. Davis, John R. Strom, Charles N. Stewart, Jon R. Salvati, Robert L. Vivenzio
  • Publication number: 20040183482
    Abstract: An adapter for permitting a medical diagnostic instrument having an illumination source including at least one LED (light emitting diode) to be used with a power supply normally configured for use with a diagnostic instrument having at least one incandescent lamp as an illumination source. The adapter includes circuitry for compensating LED specific characteristics for permitting the power supply to be used with the LED.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Applicant: Welch Allyn, Inc.
    Inventors: Chris R. Roberts, Corinn C. Fahrenkrug, Allan I. Krauter, Shawn A. Briggman, Michael A. Pasik, Peter J. Davis, John R. Strom, Charles N. Stewart, Jon R. Salvati, Robert L. Vivenzio
  • Patent number: 5394057
    Abstract: An arc tube of fused silica for a metal halide arc discharge lamp including a fill for the arc tube comprised of a sodium halide, at least one additional metal halide, and an inert starting gas, the arc tube including a tube of fused silica having an inner wall defining an arc chamber, the inner wall of the tube having provided thereon a metal silicate coating which is vitreous and light-transmissive, and which is comprised of a silicate of at least one metal selected from the group consisting essentially of scandium, yttrium, and a rare earth element, and preferably which is the same metal as that of the at least one additional metal halide. Protection of the fused silica arc tube with the metal silicate coating reduces loss of the metallic portion of the fill by diffusion or reaction and corresponding buildup of free halogen in the arc tube.
    Type: Grant
    Filed: August 7, 1992
    Date of Patent: February 28, 1995
    Assignee: General Electric Company
    Inventors: Timothy D. Russell, Curtis E. Scott, Charles N. Stewart, Ranajit K. Datta, Mary S. Kaliszewski, Paul G. Mathews
  • Patent number: 5013968
    Abstract: Metal halide vapor arc lamps for reprographic and projection processes emitting in the blue, green and red bands with excellent primary color separation and having long life and lumen maintenance contain mercury, zinc, indium, lithium, thallium, a halogen and a rare earth metal such as lanthanum, scandium or dysporsium in the arc tube.
    Type: Grant
    Filed: March 10, 1989
    Date of Patent: May 7, 1991
    Assignee: General Electric Company
    Inventors: Timothy D. Russell, Carl H. Hess, Paul G. Hlahol, Charles N. Stewart
  • Patent number: RE44806
    Abstract: An adapter for permitting a medical diagnostic instrument having an illumination source including at least one LED (light emitting diode) to be used with a power supply normally configured for use with a diagnostic instrument having at least one incandescent lamp as an illumination source. The adapter includes circuitry for compensating LED specific characteristics for permitting the power supply to be used with the LED.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: March 18, 2014
    Assignee: Welch Allyn, Inc.
    Inventors: Chris R. Roberts, Corinn C. Fahrenkrug, Allan I. Krauter, Shawn A. Briggman, Michael A. Pasik, Peter J. Davis, John R. Strom, Charles N. Stewart, Jon R. Salvati, Robert L. Vivenzio