Patents by Inventor John G. Parker

John G. Parker 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).

  • Two-band optical comparator for use with chopped CW singlet oxygen monitor
    Patent number: 4827938
    Abstract: An improved apparatus and method for detecting singlet oxygen emission produced during photoradiation is disclosed. The invention utilizes a two-band optical comparator to detect optical emissions. The optical comparator comprises an in-band filter that passes light in the 1270 nm singlet oxygen emission band and an out-of-band filter that passes light outside of the 1270 nm singlet oxygen emission band. The signal detected when the out-of-band filter is used is composed essentially of a fluorescence emission. This detected signal is used to synchronize an electronic reference signal. The electronic reference signal is used by a signal processing means to isolate a phase delayed singlet oxygen emission component which appears with a fluorescence emission component in the 1270 nm singlet oxygen emission band.
    Type: Grant
    Filed: August 9, 1988
    Date of Patent: May 9, 1989
    Assignee: The Johns Hopkins University
    Inventor: John G. Parker
  • Electro-optical device and method for monitoring instantaneous singlet oxygen concentration produced during photoradiation using pulsed excitation and time domain signal processing
    Patent number: 4592361
    Abstract: A method and apparatus is disclosed for optically monitoring the concentration of singlet oxygen produced during photoradiation. A composite optical emission in the 1.27 micron frequency band is detected and electrically processed to separate a first component due to the decay of singlet oxygen from a second unwanted component due to the fluorescence of the photosensitizing dye.A pulsed excitation source is used to excite the photosensitizing dye and a time domain signal processor, such as a box-car integrator, is used to separate and process the singlet oxygen emission component in the time domain.The magnitude and/or other characteristics of the singlet oxygen emission component can be used to determine properties of complex biological or other media. In a therapeutic environment the magnitude and/or other characteristics of the singlet oxygen emission can be used by the treating physician to set a therapeutic light dosimetry.
    Type: Grant
    Filed: July 11, 1984
    Date of Patent: June 3, 1986
    Assignee: The Johns Hopkins University
    Inventors: John G. Parker, William D. Stanbro
  • Electro-optical device and method for monitoring instanteous singlet oxygen concentration produced during photoradiation using a CW excitation source
    Patent number: 4576173
    Abstract: A method and apparatus is disclosed for optically monitoring the concentration of singlet oxygen produced during photoradiation. A composite optical emission in the 1.27 micron frequency band is detected and electrically processed to separate a first component due to the decay of singlet oxygen from a second unwanted component due to the fluorescence of the photosensitizing dye.A chopped CW excitation source is used to excite the photosensitizing dye and a signal processing means such as a lock-in amplifier is used to separate the singlet oxygen emission component which appears out of phase from the chopped excitation signal and the in-phase photosensitizer fluorescence.The magnitude and/or other characteristics of the singlet oxygen emission component can be used to determine properties of complex biological or other media. In a therapeutic environment the magnitude and/or other characteristics of the singlet oxygen emission can be used by the treating physician to set a therapeutic light dosimetry.
    Type: Grant
    Filed: July 11, 1984
    Date of Patent: March 18, 1986
    Assignee: The Johns Hopkins University
    Inventors: John G. Parker, William D. Stanbro
  • Localization of cancerous tissue by monitoring infrared fluorescence emitted by intravenously injected porphyrin tumor-specific markers excited by long wavelength light
    Patent number: 4541438
    Abstract: An improved apparatus and method for optically localizing cancer lesions occluded beneath healthy tissue layers. A porphyrin tumor-specific marker is injected into a patient. After several days the healthy tissue has released the tumor-specific marker but the cancerous tissue has retained the tumor-specific marker. A long wavelength red excitation light illuminates an area of tissue and excites the porphyrin tumor-specific marker to fluorescence. An optical detection means monitors fluorescent emissions in the near infrared band and locates the source of the emissions.
    Type: Grant
    Filed: June 2, 1983
    Date of Patent: September 17, 1985
    Assignee: The Johns Hopkins University
    Inventors: John G. Parker, William D. Standbro