Abstract: A device having a flow channel, wherein at least one flow-terminating interface is used to control the flow of liquid in the flow channel. The flow-terminating interface prevents the flow of the liquid beyond the interface. In one aspect, the invention provides a sensor, such as, for example, a biosensor, in the form of a strip, the sensor being suitable for electrochemical or optical measurement. The sensor comprises a base layer and a cover layer, and the base layer is separated from the cover layer by a spacer layer. The base layer, cover layer, and spacer layer define a flow channel into which a liquid sample is drawn therein and flows therethrough by means of capillary attraction. The flow of the sample is terminated by a flow-terminating interface positioned in the flow channel.

Abstract: A method for determining the value of MCV of a fresh sample of blood when the value of MCV for that sample of blood is known, but the period of time that the sample of blood has been stored is not known. The method of this invention allows an automated hematology analyzer to provide a more reliable indication of the initial value of MCV of a sample of blood, i.e., the value of MCV that would have been expected for the sample of blood when the sample was fresh. Furthermore, the method of this invention uses data that is readily available as part of the blood count data.

Abstract: An apparatus and method for dispensing protein-containing materials, such as, for example, pastes, gels, lipidic cubic phases, lipidic mesophases, and mixtures of the foregoing into containers, e.g., wells of assay trays. The invention further provides a method for preparing the aforementioned containers for various experiments involving soluble proteins or membrane proteins or both types of proteins. In a preferred embodiment, the apparatus includes (a) a gel dispenser assembly for dispensing small quantities of gels; (b) a pipette probe for dispensing fluids; (c) an actuator for moving the gel dispenser assembly vertically relative to the pipette probe; (d) a liquid-handling robot having a robot arm for moving the pipette probe and the gel dispenser assembly vertically and horizontally relative to containers, e.g.

Abstract: A connector suitable for connection of at least three different types of containers to administration sets, preferably enteral administration sets, and feeding tubes. The containers contain nutritional feed for administration thereof to various types of patients who require enteral nutrition. In one aspect, the connector comprises three different segments: (a) a first segment for connecting containers having mouths having a relatively large diameter, such as, for example, plastic and glass bottles having mouths having diameters of approximately 40 mm; (b) a second segment for connecting containers having mouths having a relatively intermediate diameter, such as, for example, crown cap bottles having mouths having diameters of approximately 26 mm; and (c) a third segment for connecting containers having mouths having relatively small diameters, such as, for example, flexible pouches having mouths having diameters of approximately 12.5 mm.

Abstract: A biosensor in the form of a strip. In one embodiment, the biosensor strip comprises an electrode support, a first electrode, i.e., a working electrode, a second electrode, i.e., a counter electrode, and a third electrode, i.e., a reference electrode. Each of the electrodes is disposed on and supported by the electrode support. Each of the electrodes is spaced apart from the other two electrodes. The biosensor strip can include a covering layer, which defines an enclosed space over the electrodes. This enclosed space includes a zone where an analyte in the sample reacts with reagent(s) deposited at the working electrode. This zone is referred to as the reaction zone. The covering layer has an aperture for receiving a sample for introduction into the reaction zone. The biosensor strip can also include at least one layer of mesh interposed in the enclosed space between the covering layer and the electrodes in the reaction zone.

Abstract: Method and apparatus for obtaining a sample of blood from a patient for subsequent diagnostic tests, e.g., glucose monitoring. In one aspect of the invention, the method comprises the steps of: (a) placing a blood collection device over a region on the surface of the skin from which said sample is to be obtained, (b) forming a seal between said blood collection device and said surface of the skin, (c) creating a vacuum sufficient to result in said surface of the skin becoming stretched and engorged with blood, (d) triggering a lancing assembly and causing a lancet to penetrate said skin, (e) retracting said lancet, (f) withdrawing blood toward and onto a fluid collector, and (g) releasing the vacuum. In another aspect of the invention, an apparatus for carrying out the method described previously is provided.

Abstract: A system for measuring a biological parameter, such as blood glucose, the system comprising the steps of directing laser pulses from a light guide into a body part consisting of soft tissue, such as the tip of a finger to produce a photoacoustic interaction. The resulting acoustic signal is detected by a transducer and analyzed to provide the desired parameter.

Abstract: Sensors that are capable measuring the rate of flow of a fluid that passes over the electrodes of the sensor. In these sensors, an electrode, designated the flow rate-determining electrode, is used in conjunction with the conventional electrodes, e.g., the working electrode, the reference electrode, and the counter electrode, to determine the rate of flow of the fluid. In one aspect, this invention provides a sensor for measuring the concentration of an analyte in a sample of fluid when the sample flows continuously over the electrodes of the sensor, especially when the rate of flow of the sample is relatively low. In another aspect, this invention provides a method for measuring the concentration of an analyte in a sample of fluid, wherein the rate of flow of the sample varies during the period of time that the sensor is in place. In a preferred embodiment, the sensor employs four electrodes, namely, a working electrode, a reference electrode, a counter electrode, and a flow rate-determining electrode.

Abstract: The present invention involves apparatus and methods for use in collecting bodily fluids, such as interstitial fluids, from the epidermal layer of an animal. A preferred apparatus includes a pressure head and, optionally, a holder therefor for supplying a positive pressure to the head. The methods include the application of a positive pressure to the area surrounding an epidermal site from which stratum corneum has been breached, such as by laser ablation, to cause bodily fluids, such as interstitial fluids, to exude from the site and collecting the fluids exuding therefrom.

Abstract: Apparatus and method for determining at least one parameter, e.g., concentration, of at least one analyte, e.g., urea, of a biological sample, e.g., urine. A biological sample particularly suitable for the apparatus and method of this invention is urine. In general, spectroscopic measurements can be used to quantify the concentrations of one or more analytes in a biological sample. In order to obtain concentration values of certain analytes, such as hemoglobin and bilirubin, visible light absorption spectroscopy can be used. In order to obtain concentration values of other analytes, such as urea, creatinine, glucose, ketones, and protein, infrared light absorption spectroscopy can be used. The apparatus and method of this invention utilize one or more mathematical techniques to improve the accuracy of measurement of parameters of analytes in a biological sample.

Abstract: A multichemistry measuring device and diagnostic test strips which, in combination with the multichemistry measuring device, provide a multichemistry testing system are disclosed. The test strips are for chemical analysis of a sample, and are adapted for use in combination with a measuring device having a test port and capable of performing a multiplicity of testing functionalities. Each type of test strip corresponds to at least one of the testing functionalities, and at least some types of test strips have indicators of the testing functionality on them. The test port is adapted for use in combination with a multiplicity of different types of test strips and includes a sensor capable of specifically interacting with the indicator(s) on the test strips, thereby selecting at least one of the multiplicity of testing functionalities corresponding to the type of test strip.

Abstract: Disclosed is an improved electrode for use in an electrochemical sensor for measuring an analyte in a sample. The electrode includes a thin working layer whose thickness is from 2 to 10 microns. Also disclosed is an electrode strip that includes an electrode with a thin working layer. Typically, the thin working layer includes an enzyme and a redox mediator. In an electrode for measuring glucose, the enzyme can be glucose oxidase and the redox mediator can be ferrocene.

Abstract: A method and apparatus for calibrating a sensor for determination of the concentration of a sterilant, e.g., hydrogen peroxide vapor, in a sterilization system. This invention provides a method for calibrating a sensor that is used for measuring the quantity of a sterilant in a system for delivering the sterilant, the method comprising the steps of: (a) generating reference calibration data, the reference calibration data showing a mathematical relationship between a measurable parameter, e.g. voltage, and a quantity of the sterilant, e.g.

Abstract: Cyanide-free reagents for the determination of hemoglobin and leukocytes present in a blood sample comprise an aqueous solutions of at least one quaternary ammonium salt, preferably selected from the group of alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts or alkylpyridium salts consisting of tetradecyltrimethyl ammonium bromide (TTAB), dodecyltrimethyl ammonium chloride, cetyltrimethyl ammonium bromide, hexadecyltrimethyl ammonium bromide and benzalkonium chlorides, and hydroxylamine salts, especially hydrochloride, sulfate and phosphates and other acid salts. The method involves mixing the reagent with a diluent-diluted blood sample, presenting it to an absorbance spectrophotometer and measuring the resulting optical density as an indicator of hemoglobin concentration. This cyanide-free reagent could be used solely for hemoglobin determinations, or, it can also be used in leukocyte counting and sizing using hematology instrumentation.

Abstract: The present invention is based on the discovery of NAD+ and NADP+ mediator compounds that do not bind irreversibly to thiol groups in the active sites of intracellular dehydrogenase enzymes. Such mediator compounds avoid a common mode of enzyme inhibition. The mediators can therefore increase the stability and reliability of the electrical response in amperometric electrodes constructed from NAD- or NADP-dependent enzymes.

Abstract: An electrochemical cell having an auxiliary area that contains a redox species on a working electrode. The auxiliary area provides a low resistance current path between the working electrode and a pseudo reference/counter electrode. The auxiliary area is an integral part of the working electrode and allows an enhanced current to flow. The enhanced current adds to the measurement signal. This reduces non-monotonic current decay, which can lead to erroneous analyte measurements.