Research International, Inc.

Metricor, Inc.

David A McCrae

Elric W Saaski

Chuck C Jung

Dale M Lawrence

James C Hartl

Roger A Wolthuis

Optical assay apparatus and methods are provided having an optical assay cup for detecting analytes in a sample fluid. The cup's sidewall may include an optical waveguide having a detection coating on its inner surface. During use, the waveguide receives evanescent or darkfield interrogation light, interrogates at least part of cup's interior volume with it, and emits signal light as a function of the analytes. The detection coating may have fluid or non-fluid detection layers, at least part of which may form at least part of a waveguide for the interrogation light. The cup may be spun during use, such as to centrifugally-concentrate any high-density analytes towards cup's sidewall. The assay apparatus may further include an interrogation light source, a cover or spinning apparatus for the cup, and an optical detector for the signal light.

Optical assay apparatus and methods

An air sampler having a fan; an air inlet tube; a main body having a cyclonic cup, a stripping column and a demister; and fluidic circuitry for inputting fluids to the main body and the air inlet tube, and for outputting fluids from the main body. Air flow through the air sampler may be generated by a fan that is either external or internal with respect to the main body's cyclonic cup. A thin film of stripping liquid and/or a fog of stripping liquid particles in the air inlet tube, the cyclonic cup, the stripping column and/or the demister strip a target material from the air flow through the air sampler. A passive fog generating slot or a passive spiral fog generating nozzle may be placed over the fluid input conduit in the center of the cyclonic cup. The air sampler's main body and/or an air inlet tube may be integrally formed as one part. The main body's inner surfaces may be selected to be hydrophilic, for better flow of the thin film of stripping liquid across them; and its intersecting internal surfaces may be provided with smoothly curved fillets for better air and liquid flow over them. The air sampler may be provided with a liquid level control that may have a reservoir float monitored by external optical sensors; a flexible, capacitive effect, dual electrode bearing substrate that is wrapped around the exterior of the air sampler's stripping column; or an external optical bubble sensor for the reservoir's output conduit. The air sampler may be so small, light and low in energy consumption that it may be battery powered and human-portable; and may be so efficient that it may be used to strip target material that is present in the incoming air in concentrations of only a few parts per trillion, or less.

Air sampler

High efficiency wetted surface cyclonic air sampler

An air sampler which has an air impeller mounted within a cyclonic cup housing. A thin film of stripping liquid and/or fog of stripping liquid particles within the sampler strip target material from the air flowing through it. The inner surfaces of the sampler may be selected to be hydrophilic, for better flow of the thin film of stripping liquid across them. The stripping target material concentration in it. The sampler may be so small, light and low in energy consumption that it may be battery powered and human-portable; and may be so efficient that it may be used to strip target material that is present in the incoming air in concentrations of only a few parts per trillion, or less.

High efficiency a wetted surface cyclonic air sampler

A multifunctional sensor system for an intrinsic type optical sensing fiber. A numerical aperture controlling optical input element for the excitation fiber may maximize the amount of sensing fiber modulated return light. The excitation fiber may be centered in a ring or linear array of return fibers, to inject excitation light into the return light poor center of the sensing fiber; and to capture return light from the return light rich outer parts of the sensing fiber. Tipping the return fibers with respect to the sensing fiber may increase their capture of high numerical aperture return light. The sizes and number of the adjacent ends of the excitation, return and sensing fibers may be selected to minimize the effects of any lateral displacement between the adjacent ends. The sensing fiber may generate both reference and sensor return light; and a ratiometric output signal may be derived from the reference and sensor return light which may be free of certain system errors. Ribbon-like sensor and sensing fibers may be provided; along with a transition fiber if the sensor and sensing fibers are of different sizes. An annular, possibly tapered, waveguide may be provided around the sensing fiber, to better capture the return light. The waveguide may either pass the target objective; or it may be hollow, and define a sample chamber for the target objective. The ends of the sensing fiber and/or the annular waveguide may be mirrored, to dramatically increase the output of return light, and thus, the sensitivity of the sensor system.

Multifunctional sensor system

An oxygen sensor contains an indicator whose change in absorption is a function of the concentration of oxygen in a sample bathing the indicator. Light transmitted and reflected through the indicator of the sensor undergoes an absorption that is characteristic of the concentration of oxygen. The indicator is a viologen whose absorption returns to a steady-state value after it has been subjected to a pulse of short-wavelength light. The rate at which the absorption returns to the steady-state value is a function of the concentration of oxygen bathing the viologen indicator. A measurement system for use with the pO.sub.2 sensor causes a short-wavelength flash to be sent to the sensor and thereafter monitors the time-varying absorption of the sensor to measure the oxygen content of the sample bathing the viologen indicator.

Optical oxygen sensor

An optical pH sensor and a gas sensor utilizing the pH sensor. The pH sensor includes an indicator whose absorbance is a function of the concentration of hydronium ions in a media surrounding the indicator. Light transmitted and reflected through the indicator of the sensor undergoes an absorption that is characteristic of the concentration of the hydrogen ion. The pH sensor can be used as to sense the concenration of a gas in a sample by surrounding the indicator with a liquid or liquid-containing media that changes pH as it is exposed to the gas, and separating the indicator and liquid or liquid-containing media from the gas with a membrane that is permeable to the gas to be measured. A measuring system used with the sensors transmits coherent radiation to the sensor through an optical fiber, separates the radiation returning from the sample into two wavelength bands, and digitally samples the photocurrents produced within the two wavelength bands. A microprocessor performs ratiometric calculations to measure the pH or gas concentration.

Growing community of inventors

Richmond, CA, United States of America

David A McCrae