Abstract: A diffused light reflectance readhead is disclosed. The readhead employs an improved light emitting diode (LED) providing a more strongly collimated beam of fight around a beam axis onto a reagent test pad. The reagent test pad is supported on a strip guide at an angle .alpha. of 5 degrees with respect to the perpendicular of the beam axis. It has been discovered that when .alpha. is between 3 and 8 degrees that specular reflection is dramatically reduced in relation to the small reduction in reflected light received by a sensor. The diffuse reflected light travels to the sensor by passing through a staircase optical baffle at an angle of 45 degrees to the perpendicular of the beam axis. The sensor converts the optical signal into an electrical one for processing and analysis. One embodiment of the present invention can detect the presence of glucose in a blood sample.

Abstract: Disclosed is a device for discriminating the right sides of test strips in an automated analyzer for arranging the test strips such that the right sides thereof may face in one direction, which comprises: suction holes formed on a transportation stage to be aligned in the direction orthogonal to the direction that the test strips are moved, at the positions corresponding to the intervals between test pads impregnated with reagents of the test strip; and suction holes formed on a turntable disposed subsequent to the transportation stage, at the positions corresponding to the intervals between the test pads impregnated with reagents of the test strip.

Abstract: An improved device and method of separating the cellular components of whole blood from plasma or serum and assaying the plasma or serum for a predetermined soluble constituent are disclosed. The device includes a filter pad, that separates the cellular components of whole blood from the serum or plasma, and a test pad, that assays the serum or plasma for a predetermined soluble constituent. The filter pad effectively separates and retains cellular components of the whole blood sample, thereby eliminating assay interference by the cellular components of whole blood.

Abstract: A test strip pick-up mechanism in an automated analyzer, which comprises: a bottle holder removably holding a test strip bottle containing a plurality of test strips and having a pierced groove formed in the peripheral direction and a test strip pick-up portion connected to the groove and formed in the longitudinal direction; a bottle turning motor connected to the bottle holder; a guide member extended from the inner part of the bottle holder in parallel to the central axis of the test strip bottle and having a L-shaped guide portion formed over the entire length of the guide member with suction holes for adsorbing the test strips being formed on the guide portion which is adjacent to the test strip pick-up portion; claws engaged with the groove of the bottle holder; an air chuck having suction holes for drawing out the test strips contained in the test strip bottle; a movable member on which the air chuck is mounted; a test strip drawing out motor connected to the movable member via a guide bar; depressing

Abstract: A fluid sensing pipette includes an outer conductive tube forming a first electrode and an inner conductive tube forming a second electrode. The inner conductive tube is disposed concentrically within the outer conductive tube. To insulate the inner conductive tube from the outer conductive tube, the inner conductive tube is coated with a thin, uniform, and consistent Parylene coating. A hydrophobic polymeric tube is disposed concentrically within the inner conductive tube to prevent cross-contamination between different biological samples aspirated into the pipette. The inner and outer conductive tubes are separately coupled to a level detection circuit which permits the pipette to detect entry of the pipette into a conductive fluid. The level detection circuit determines the impedance between the first and second electrodes and produces a control signal in response to the impedance falling below a predetermined threshold.

Abstract: A test strip overturning mechanism in an automated analyzer for arranging test strips such that the right sides thereof may face in one direction, which comprises: an overturning device having an arm portion with suction holes being formed thereon; and a motor connected to the overturning device via a rotary shaft, wherein the suction holes formed on the arm portion are aligned in a straight line with suction holes formed on a transportation stage, arranged in the direction orthogonal to the direction that the test strips are moved; and a turntable is disposed at the position corresponding to the location of the arm portion when the overturning device is turned 180.degree. around the rotary shaft.

Abstract: Test devices are disclosed which are useful for determining glucose or occult blood comprising a carrier matrix, glucose oxidase, an indicator system and a glucose derivative that upon addition of water hydrolizes to produce glucose.

Abstract: A diffused light reflectance readhead is disclosed. The readhead employs an improved light emitting diode (LED) providing a more strongly collimated beam of light around a beam axis onto a reagent test pad. The reagent test pad is supported on a strip guide at an angle .alpha. of 5 degrees with respect to the perpendicular of the beam axis. It has been discovered that when .alpha. is between 3 and 8 degrees that specular reflection is dramatically reduced in relation to the small reduction in reflected light received by a sensor. The diffuse reflected light travels to the sensor by passing through a staircase optical baffle at an angle of 45 degrees to the perpendicular of the beam axis. The sensor converts the optical signal into an electrical one for processing and analysis. One embodiment of the present invention can detect the presence of glucose in a blood sample.

Abstract: A test device for determining the presence of leukocyte cells, esterase or protease in a test sample is disclosed. The test device comprises a carrier matrix having a reagent composition incorporated therein, wherein the reagent composition comprises a lactate ester having the structure ##STR1## wherein A is an alcohol blocking group, and wherein B--O-- is a residue of compound B--OH and provides a detectable response when the lactate ester is hydrolyzed; and a buffer. In a preferred embodiment, the lactate ester has the structure ##STR2## wherein X is O, S or NR.sup.2, R is aryl or lower alkyl, R.sup.1 is hydrogen or lower alkyl, and R.sup.2 is hydrogen, lower alkyl or aryl.

Abstract: A composition, test device and method of determining the presence or concentration of ketone bodies, and specifically D-.beta.-hydroxybutyrate, in a test sample are disclosed. The test device includes a test pad comprising a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with D-.beta.-hydroxybutyrate to produce a detectable or measurable response. In addition, a new and improved indicator reagent composition, comprising a) an indicator dye that is responsive to thiols, such as a substituted isobenzothiazolone, Ellman's reagent or a derivative of Ellman's reagent; b) D-.beta.-hydroxybutyrate dehydrogenase; c) lipoamide dehydrogenase; d) D,L-lipoamide; and e) nicotinamide adenine dinucleotide, is incorporated into the carrier matrix to provide an accurate and sensitive assay of a test sample for D-.beta.-hydroxybutyrate (DHBA) in particular, and for ketone bodies in general.

Abstract: A composition and method for determining the presence of leukocyte cells, esterase or protease in a test sample are disclosed. The composition contains a lactate ester having the structure ##STR1## wherein A is an alcohol blocking group, and wherein B-O- is a residue of compound B-OH and provides a detectable response when the lactate ester is hydrolyzed; and a buffer. One class of lactate ester has the structure ##STR2## wherein X is O, S or NR.sup.2, R is aryl or lower alkyl, R.sup.1 is hydrogen or lower alkyl, and R.sup.2 is hydrogen, lower alkyl or aryl.

Abstract: An improved device and method of a) separating the cellular components of whole blood from plasma or serum, b) separating the low density lipoprotein (LDL) fraction and the very low density lipoprotein (VLDL) fraction from the plasma or serum, then c) assaying the plasma or serum for cholesterol present in the high density lipoprotein (HDL) fraction are disclosed. The device includes a separation area that separates the cellular components of whole blood from the serum or plasma and separates the LDL and VLDL fractions from the serum or plasma, and a test area that assays the serum or plasma for the concentration of the HDL cholesterol. The method includes introducing a whole blood sample to a test device including a separation area comprising a first zone that separates the cellular components of the whole blood from the plasma or serum; and a second zone that separates the LDL and the VLDL fractions from the plasma or serum.

Abstract: The detection of protein is accomplished using novel composition and method involving phenolsulfonephthalein protein error indicator, buffer and an aliphatic ether-polycarbonate present in an amount equal to or less than ten percent by weight.

Abstract: The buttonless memory system of the present invention retrieves and stores the measurement results of a sample for the user of an electronic measurement device, particularly a portable and personal electrical measurement device, with minimal user interaction. The user simply activates the portable measurement device and waits as the buttonless memory system initially cycles through the stored measurement results. The buttonless memory system stops retrieving from memory when the measurement device detects a sample or control solution. After test measurement of the sample, the user can choose to store the measurement result by deactivating the measurement device during the time the memory display is on. If the sample is a control solution, the user can delete the measurement result from memory by waiting and deactivating the measurement device after the memory display is off. In this way, the buttonless memory system provides a simple and effective memory management scheme for measurement devices.

Abstract: A video test strip reader uses a video imager or camera for viewing a viewing field containing reagent test strips each having test pads reacted with a specimen containing constituents of interest. The video imager produces an analog signal representing an image of the viewing field. An image handler coupled to the video imager converts or digitizes the analog signal into a digital signal representing the image and stores the image in the form of an array of pixels representing the image. Each pixel contains color information broken down into red, green or blue (RGB). A processor coupled to the image handler analyzes the array of pixels, determines the location and orientation of a test strip, identifies the test areas on the test strip, measures the corresponding test areas on the strip at the proper times and calculates the test results, such as the concentration of the constituents of interest in the specimen or other measurable properties of the specimen such as color or specific gravity, etc.

Abstract: A method, composition and test device for determining the ionic strength or specific gravity of a test sample are disclosed. The method utilizes a test device comprising a test pad, wherein the test pad includes a carrier matrix incorporating a reagent composition capable of producing a detectable and measurable response that correlates to the ionic strength and the buffer capacity, and therefore the specific gravity, of the test sample. The reagent composition, comprising a strong polyelectrolyte, an indicator comprising: (i) a dye that is metachromatic and sensitive to pH changes, or (ii) or a combination of metachromatic dye and a pH indicator dye, in a suitable carrier, and buffered at a pH of 3 or less, is incorporated into a carrier matrix to provide a test pad of a device useful in an ionic strength or specific gravity assay of a test sample.