Abstract: The present invention relates to cost effective analytical instruments for determining the presence or amount of an analyte in a sample. The analytical instruments utilize an assay cartridge which has a sample receiving port and a rotatable carousel containing a plurality of reagent wells. Each reagent well includes a piston element for delivery of reagent to a test surface. The instrument is capable of indexing the assay cartridge to deliver sample and reagents to a test surface in a predetermined and flexibile manner, thus providing an assay protocol which is specific to the type of sample under analysis. The invention also relates to components, features, disposables, reagent delivery systems, accessories, and methods for using such instruments. Appropriate applications include infectious disease testing, cancer detection and monitoring, therapeutic drug level monitoring, allergy testing, environmental testing, food testing, diagnostic testing of human and veterinary samples, and off-line process testing.

Abstract: Improvements in a biosensor are disclosed. A biosensor includes a waveguide, at least a portion of which is substantially planar. One or more reservoirs may be formed adjacent to a chemistry-bearing surface of the waveguide. The biosensor may include a gasket to form a seal between the waveguide and side walls of the reservoir. A sample solution may be introduced into the reservoir or otherwise onto the surface of a waveguide through an input port. Waveguides of varying composition (e.g., plastic, quartz, glass, or other suitable waveguide materials) may be used in the biosensor. Also disclosed is a sled-shaped waveguide, which includes a planar portion and a lens at an end thereof and angled relative thereto for coupling light into the waveguide.

Abstract: Improvements in a biosensor are disclosed. A biosensor includes a waveguide, at least a portion of which is substantially planar. One or more reservoirs may be formed adjacent to a chemistry-bearing surface of the waveguide. The biosensor may include a gasket to form a seal between the waveguide and side walls of the reservoir. A sample solution may be introduced into the reservoir or otherwise onto the surface of a waveguide through an input port. Waveguides of varying composition (e.g., plastic, quartz, glass, or other suitable waveguide materials) may be used in the biosensor. Also disclosed is a sled-shaped waveguide, which includes a planar portion and a lens at an end thereof and angled relative thereto for coupling light into the waveguide.

Abstract: Improvements in a biosensor of the type having reservoirs or wells for analyzing a biological liquid are disclosed. A biosensor includes a waveguide placed between a plurality of members such as plates at least one of the members being formed to define the walls of the reservoirs where the liquid is biologically analyzed. The walls of the reservoirs are made of an inert, opaque material such as a metal. Although the biosensor may include a gasket, the gasket is associated with the members and waveguide in such a way (e.g., by recessing the gasket into a channel formed into a metal plate) so that the gasket does not form any significant portion of the reservoir wall. Waveguides of varying composition (e.g., plastic, quartz or glass) may be associated with the members to form the biosensor. The metal plate of the biosensor has input and output ports for infusing, draining, or oscillating the liquid to be analyzed in the reaction reservoir.

Abstract: The present invention relates to a instrument for use in an air abrasion dental instrument that allows direct contact between a nozzle which delivers a stream of abrasive particles directly through a primary opening to a tooth surface. As the primary opening if the nozzles of this invention are in continuous close contact with a tooth surface, exhaust amounts of abrasive-laden fluid escape secondary openings at a direction lateral to the tooth surface. The invention also embodies removable nozzle covers having both primary and secondary openings that enable prior art nozzles to be easily converted to contact nozzles. Both the nozzles and removable nozzle covers of this invention define areas for dental restoration that remove a minimal amount of healthy tooth structure. The invention allows the comfort of air abrasion dentistry to the patient as well as both visual and tactile feedback to the dentist, the latter filling a long felt need of the practicing dental community.

Abstract: Improvements in a biosensor of the type having reservoirs or wells for analyzing a biological liquid are disclosed. A biosensor (190) includes a waveguide (164) placed between a plurality of members such as plates (100, 186), at least one of the members (100) being formed to define the walls (132, 134, 136) of the reservoirs where the liquid is biologically analyzed. The walls of the reservoirs are made of an inert, opaque material such as a metal. Although the biosensor may include a gasket (162), the gasket is associated with the members and waveguide in such a way (e.g. by recessing the gasket into a channel formed into a metal plate) so that the gasket does not form any significant portion of the reservoir wall. Waveguides of varying composition (e.g. plastic, quartz or glass) may be associated with the members to form the biosensor. The metal plate of the biosensor has input and output ports for infusing, draining, or oscillating the liquid to be analyzed in the reaction reservoir.

Abstract: A fluid delivery system (10) is provided for delivering at least one chemical (26) onto a field in a desired concentration. A carrier fluid (67) is provided for diluting the farm chemical (26). The mixture is pumped through a spray boom (18) onto the field by a main fluid pump (74). The chemical (26) is delivered to the inlet port (76) of the main fluid pump (74) by a chemical pump (54). The chemical pump (54) is operated by a variable speed stepping motor (56). The speed of the stepping motor (56) is controlled by a speed sensing wheel (88) to provide a uniform concentration of chemical on the field independent of vehicle speed. The motor speed is also controlled by a thumbwheel switch (116) to deliver a desired concentration on the field compensating for drive vehicle wheel slippage. The motor speed is also adjusted to calibrate the delivery concentration to the nozzle pattern through calibration switches.

Abstract: A bimodal automatic lens focussing apparatus including detection and switching means for detecting a loss in a localized focal condition and switching to a search mode wherein the objective lens is scanned between its outer limits to reacquire focus. Photodiode arrays sense respective light images on either side of the desired focal plane, and the resulting signals are processed to drive the lens to the desired focal plane. A level discriminator monitors the processed signals. Upon detection of a loss of the localized focus condition a mode switch is gated to couple a ramp generator to the lens driver. The lens is scanned between its outer limits until the level discriminator again detects the localized focus condition and the ramp generator is decoupled from the lens driver.

Abstract: Improvements in a biosensor of the type having reservoirs or wells for analyzing a biological liquid are disclosed. A biosensor (190) includes a waveguide (164) placed between a plurality of members such as plates (100, 186), at least one of the members (100) being formed to define the walls (132, 134, 136) of the reservoirs where the liquid is biologically analyzed. The walls of the reservoirs are made of an inert, opaque material such as a metal. Although the biosensor may include a gasket (162), the gasket is associated with the members and waveguide in such a way (e.g. by recessing the gasket into a channel formed into a metal plate) so that the gasket does not form any significant portion of the reservoir wall. Waveguides of varying composition (e.g. plastic, quartz or glass) may be associated with the members to form the biosensor. The metal plate of the biosensor has input and output ports for infusing, draining, or oscillating the liquid to be analyzed in the reaction reservoir.