University of Washington

Korry Electronics Co.

The United States of America As Represented by the United States

Mathematical Sciences Northwest, Inc.

Leonard Y Nelson

Eric J Seibel

Charles David Melville

Richard Stephen Johnston

Timothy D Soper

Cameron M Lee

Timothy R Robinson

John R Green

Melvin I Buchwald

Claude R Jones

Jasmine Graham

Manuja Sharma

Liang Zhang

Chenying Yang

Joel Berg

Stephen E Moody

Jack Grynberg

Carol W Wong

Systems and methods for accurate optical pH sensing of biofilms are disclosed. In one embodiment, a method of measuring an extracellular pH level using multiple wavelengths emitted by a fluorescent substance includes: exciting the fluorescent substance at an excitation wavelength; measuring a first fluorescence intensity at a first wavelength of a fluorescence emission; and measuring a second fluorescence intensity at a second wavelength of the fluorescence emission. The second wavelength is different from the first wavelength. The method also includes determining the extracellular pH level based on the first fluorescence intensity at the first wavelength and the second fluorescence intensity at the second wavelength.

Systems and methods for accurate optical pH sensing of biofilms

A photosensitive medical tape includes a backing layer that is at least partially transparent to a first spectrum of electromagnetic radiation. The photosensitive medical tape also includes a coupling layer disposed on a first side of the backing layer to provide adhesion of the photosensitive medical tape to the human skin. The photosensitive medical tape is disposed to absorb a second spectrum of electromagnetic radiation to decrease a strength of the adhesion provided by the coupling layer. The photosensitive medical tape is also flexible.

Photosensitive medical tape

Methods and systems for detecting early stage dental caries and decays are provided. In particular, in an embodiment, laser-induced autofluorescence (AF) from multiple excitation wavelengths is obtained and analyzed. Endogenous fluorophores residing in the enamel naturally fluoresce when illuminated by wavelengths ranging from ultraviolet into the visible spectrum. The relative intensities of the AF emission changes between different excitation wavelengths when the enamel changes from healthy to demineralized. By taking a ratio of AF emission spectra integrals between different excitation wavelengths, a standard is created wherein changes in AF ratios within a tooth are quantified and serve as indicators of early stage enamel demineralization. The techniques described herein may be used in conjunction with a scanning fiber endoscope (SFE) to provide a reliable, safe and low-cost means for identifying dental caries or decays.

Dental demineralization detection, methods and systems

Improved methods, systems and apparatus relating to wide field fluorescence and reflectance imaging are provided, including improved methods, systems and apparatus relating to removal of background signals such as autofluorescence and/or fluorophore emission cross-talk; distance compensation of fluorescent signals; and co-registration of multiple signals emitted from three dimensional tissues.

Multispectral wide-field endoscopic imaging of fluorescence

A method and apparatus for ultrasonic assisted deposition of a release agent onto a workpiece is disclosed. The release agent can be any fluorinated or non-fluorinated phosphorous-containing organic acid. The workpiece can be any workpiece desired to be coated with the release agent, such as a surface needing an anti-stick coating required in a plastic casting or injection mold. Metal oxide workpiece surfaces strongly bond to fluorinated phosphorus-containing organic acids. In particular, the present invention can deposit anti-stick coatings onto smooth or porous surfaces, such as anodized aluminum and its alloys, using ultrasonic assisted deposition.

Ultrasonic assisted deposition of anti-stick films on metal oxides

A luminosity control system (10) for a fluorescent lamp (12) that has a glass enclosure (18) and a pair of lead wires (14) at each end of the glass enclosure is provided. A filament (16) is electrically coupled to each pair of lead wires. An amalgam (22) is located adjacent each filament. The amalgam releases mercury into the glass enclosure upon activation of the fluorescent lamp. A wrapped wire heater (24) is in thermal contact with a first portion of the exterior surface of the glass enclosure. The heater and a thermoelectric cooler (36) raise the temperature of the fluorescent lamp to a level above the temperature at which the fluorescent lamp produces maximum visible light as determined by mercury pressure within the glass enclosure while the amalgam releases mercury into the fluorescent lamp. Thereafter, the thermoelectric cooler (36) maintains a portion of the glass enclosure at this temperature.

Hybrid luminosity control system for a fluorescent lamp

A switch mechanism (11) comprising a red LED light source (13), a filter assembly (15) and a photodetector assembly (17) is disclosed. The photodetector assembly (17) includes two filtered photodetectors (33 and 35) that are aligned with the light source (13) either directly or via a light canal (19). The filtered photodetectors (33 and 35) are designed to detect light in different narrow wavelength bands lying within the band of energy produced by the light source (13). The filter assembly (15) includes a two-position movable element (23) located between the light source (13) and the photodetector assembly (17). The movable element (23) includes two sections (25 and 27) having different light-passing abilities. In one of the movable element positions one section (25) is located between the light source and both filtered photodetectors and in the other movable element position the other section (27) is located therebetween. Preferably, one section (25) is a thin slab of transparent material and the other section (27) is a thin slab of filter material. The transmittance of the filter dye slab (27) is such that the ratio of the energy detected by the filtered photodetectors (33 and 35) when the filter dye slab (27) is located between the light source (13) and the filtered photodetectors (33 and 35) is different than the ratio of the energy detected when the transparent slab (25) is located between the light source (13) and the filtered photodetectors (33 and 35). Thus, the difference in ratios determines the position of the movable element (23).

Wavelength encoded optical switches

Beams (11) and (13) produced by helium-neon gas lasers (10) and (12) are directed at photoacoustic absorption cells (20) and (21) containing a flowing sample gas stream recovered from coal, oil and natural gas well drilling. The common hydrocarbon gases and vapors within cell (20) highly absorb the infrared energy emitted by laser (10) thereby producing an acoustic disturbance which is detected by a transducer (34) which produces an electrical output signal proportional to the concentration of the hydrocarbon gases and vapors. The methane gas within cell (21) weakly absorbs the infrared energy of laser beam (13), and thus the resulting output signal produced by a transducer (35) serves as a reference signal for determining the methane concentration. The output signals from transducers (34) and (35) are used by data processing unit (40) to compute the total concentration of hydrocarbon gases and vapors and the concentration of methane gas within cells (20) and (21). A turnable carbon dioxide gas laser (44) produces laser beams (45) and (47) both in the infrared region which are highly absorbed by the propane and n-butane component gases, respectively, flowing through photoacoustic cell (48). The level of energy absorbed from these two beams, as determined by the energy of the acoustic disturbance produced within cell (48) induces production of an electrical output signal by transducer (56) at levels proportional to the concentrations of the propane and n-butane gases in cell (48). The output signals from transducer (56) are then used by data processing unit (40) to compute the concentrations of propane, n-butane gases and C.sub.5.sup.+ gases in the sample.

Method and apparatus for analyzing components of hydrocarbon gases

An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

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Seattle, WA, United States of America

Leonard Y Nelson