Abstract: A method of and apparatus for determining stable and labile glycated compound levels in blood. Electromagnetic energy covering a multiplicity of wavelength bands within a wavelength range from 380 nm to 2500 nm is directed into a sample volume containing blood. Portions of the energy representative of both the source energy and energy after interacting with material within the sample volume are collected. The energy portions carry information relating to the source energy and the levels of labile and stable compounds within the sample volume, respectively. The portions are converted into electrical signals representative of the intensities of the respective portions in each of the multiplicity of wavelength bands.

Abstract: The present invention is directed to an improved analyte systems which are able to compensate for interfering signals and to provide accurate detection and/or quantification of analytes in a sample. In particular, the invention describes new methods, systems, and devices for indirectly determining the presence of one or more analytes in a multi-component medium.

Abstract: The present invention provides a device and a process for detecting an analyte in a biological fluid. That device comprises a cover portion with a restricted area for sample application, a separation matrix for separation of the analyte from substances in the sample that can interfere with detection of the analyte and means for detecting the analyte. The restricted area of sample application is less than 90 percent of the cross-sectional area of the separation matrix and the separation matrix and the means for detecting analyte are under compression of between 14 to 43 percent. A process comprises applying a sample of fluid to such a device and detecting a signal generated from an interaction between the analyte and the detection means in the device.

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 sample analyzer incorporates a sensor unit for providing a desired analysis of a sample. The analyzer includes a first body portion having a sensor surface (of the sensor unit) to which a sample is applied for effecting the analysis, a second body portion which is openable and closable together with said first body portion, a chamber incorporating the sensor surface when the first and second body portions are in the closed position, at least one reservoir for holding a treatment liquid and is capable of communicating with the chamber and providing a supply of treatment liquid to the chamber when the body portions are closed.

Abstract: A method for determining the application of a sample fluid on an analyte strip using first and second derivatives. Sample fluid, such as whole blood, is applied to a reagent matrix and sensor readings, such as reflectance readings or current readings, are taken of the fluid/reagent combination. The first and second derivatives of the sensor readings are calculated. A predetermined incubation time period is begun at either a local minimum in the first derivative or a local maximum following a local minimum in the second derivative data. At the expiration of the incubation period, another sensor reading is taken which is indicative of an analyte concentration in the sample fluid (such as glucose concentration in a whole blood sample).

Abstract: Sensors (20, 50, 70) for use in detecting the presence of sugars and other analytes (target molecules). The sensor is composed of a metal complex that binds to the target molecule and releases a proton or includes an exchangable ligand which is exchanged for the target molecule during the binding interaction between the metal complex and the target molecule. The result of the binding interaction is the release of a proton, hydroxide ion or ligand species generated during the ligand exchange. Measurement of the release of proton, hydroxide ion or other ligand species from the sensor (20, 50, 70) provides an indirect indication of target molecule concentration. The metal complexes may be attached to support structures (10, 12) to provide both anchoring and positioning of the metal ions to increase selectivity of sugar/metal complex interactions. Detection systems in which pH is used as an indication of proton or hydroxide release are disclosed, as are detection systems in which Cl.sup.- release is used.

Abstract: Disclosed are water soluble azo dyes, represented by Formula I or II, and their synthesis and use. The water soluble azo dyes are synthesized by diazotizing 4-aminopyridine and coupling the resulting diazo intermediate with alkylated metanilic or orthanilic acid. To be suitable for measuring blood glucose levels, the dyes are combined with m-nitrophenyl boronic acid in an aqueous solvent. A combined ao form of the dyes with glucose shows a peak at 540 nm. At this wavelength, the absorptivity has a tendency to increase with the increasing of glucose level, which allows the measurement of blood glucose levels. ##STR1## wherein R has a 1-4 carbon atom length and is an alkyl, a hydroxy alkyl, a carboxyl-containing alkyl, or a sulfonyl-containing alkyl.

Abstract: An in vivo method and apparatus for detecting an analyte in an individual. A sensor that includes a fluorescence reagent is placed in communication with the body fluids of the individual suspected of containing the analyte in such a way that once in place said sensor does not exit the skin of the individual. The sensor is configured to retain the fluorescence reagent while allowing analyte to diffuse into and out of said sensor. The sensor is illuminated transdermally, and the fluorescence from the fluorescence reagent associated with the presence of the analyte is measured.

Abstract: The present invention is directed to a single test system and method for determining the integrated glycemic condition of a subject by measuring the concentration of glucose and the level of protein-bound glucose in a subject's body fluid, such as whole blood. The glucose concentration is indicative of the subject's immediate glycemic condition, whereas the protein-bound glucose concentration is indicative of either intermediate or long-term glycemic condition. Optionally, other analytes indicative of glycemic condition, such as ketone bodies or fatty acid derivatives, can also be measured. The present invention also provides a method of diagnosing diabetes. The invention additionally provides a method for analyzing the concentration of fructosamine in less than or equal to five minutes without the use of a reaction accelerator.

Abstract: A reagent test strip is adapted for use in a blood glucose meter. A sample of whole blood is applied to one surface of a matrix on the strip and the meter measures the reflectance of the opposite surface of the matrix at about 635 nm and 700 nm and calculates from the reflectance the concentration of glucose in the sample. The portion of the applied sample that penetrates the matrix and is visible from the testing surface does not absorb light to any appreciable extent at 700 nm. Nevertheless, the glucose-containing sample interacts with the components of the reagent-containing matrix to cause a change in reflectance at 700 nm that simulates the effect of the blood color. As a result, the strip can be used in meters that measure glucose concentration in whole blood samples in the presence of optically visible hemoglobin.

Abstract: An improved biologic electrode array and methods for manufacturing and using the same. In one aspect, a matrix of electrodes each coupled to a respective sample-and-hold circuit is provided. The electrodes and sample-and-hold circuits are integral and form an array within a single semiconductor chip, such that each sample-and-hold circuit may be loaded with a predefined voltage provided by a single, timeshared digital-to-analog converter (DAC). Further, all of the sample-and-hold circuits may be accessed through a multiplexer which may be scanned through some or all of the electrode locations. Each sample-and-hold circuit may comprise a capacitor and one or more transistor switches, the switch(es), when closed, providing electrical communication between the capacitor and a source line formed in the matrix.

Abstract: The present invention describes electrochemical sensors, preferably electrochemical biosensors, in which the reference electrode and the measuring electrode are separated from one another by a porous, electrically nonconductive sheet material.

Abstract: A diagnostic agent for glycometabolic function comprising a glucose derivative of the formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and each represents hydrogen or acyl having 2 to 8 carbon atoms, with the proviso that at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is acyl and R.sup.5 represents X or --NHCOR.sup.6 X wherein X is a radioisotope of halogen and R.sup.6 is arylene or alkylene having 1 to 3 carbon atoms.

Abstract: The present invention provides a method of using a reflectance-reading device to determine an initiation time point for measuring the chemical reaction of an analyte from a biological liquid sample on a test surface. The initiation time point is determined by using a device to read a reflectance of a test surface at a plurality of time points, and calculating the K/S ratio of the test surface at each time point according to the Kubelka-Munk equation. As the device continues to calculate a K/S ratio for each time point, the device monitors the rate of change of the K/S ratio with respect to time. The device then determines the initiation time point to be when the rate of change of the K/S ratio is maximal. The present invention also provides a method of measuring the concentration of an analyte on a test surface. The concentration is measured by determining an initiation time point according to the method described above and then measuring the concentration of the analyte at a variable end point.

Abstract: Reagent and method are offered for the screening of the functional condition of the body by the person's saliva. Reagent presents itself as an H2O solution, containing ions of Fe3+, chloride ions and multi-atom alcohol .n the concentrations 0.05-3.0M; 0.05-4.0M, and 0.1-5.0M accordingly. Screening is conducted by means of mixing of the persons saliva with the reagent in the following comparison of colour mix with control; during this an orange colour is correlated with the norm; yellow-diabetes SD-1, functional disorders of pancreas; bright-pink and red initial stages of hypertonic disease, diabetes SD-2, pathological influence of smoking; dark-red, developed forms of hypertension, diabetes SD-2, pathogenic-influence of smoking or other toxic substances, leading to the emphasized energetic disorder.

Abstract: Novel sensor devices composed of a crystalline colloidal array (CCA) polymerized in a hydrogel are disclosed. The hydrogels are characterized as being capable of shrinking and swelling in response to specific stimuli applied thereto. As the hydrogels shrink or swell, the lattice structure of the CCA embedded therein changes, thereby changing the wavelength of light diffracted by the CCA. Thus by monitoring the change in diffracted wavelength, the concentration of a stimulus is determined. The gels can be modified to sense numerous different stimuli. The sensor devices are specific in that they are modified to react with only one species or family of species. These sensors have various applications in areas including, for example, environmental and chemical systems, chemomechanical systems, sensor devices and medical diagnostic tools. Various methods for making and using these devices are also disclosed.

Abstract: A minimally intrusive and less painful, self-use microsampling device and method for the measurement of glucose and other analytes in blood are provided. The device of the invention may have one or two optical windows for measuring the concentration of an absorbent reaction product or no windows if methods other than optical absorbance is used. The sampling chamber of the device can contain analytical reagents and other additives to facilitate the sampling and analytical steps. Also provided is a fabrication method for the microsampling device.

Abstract: A method for assessing or determining alcohol consumption rates including using a blood specimen from a human subject to develop an individual blood constituent panel; comparing the individual panel with a reference blood constituent panel to provide categories corresponding to rates of alcohol consumption; and identifying the category of consumption rate. The methods of the invention can be varied through modification of one of several statistical models used therewith to preferentially weigh the analysis and identify one consumption category over another. Multi-variate and similar such statistical techniques correlate comparisons of individual/subject blood and reference panel constituents with recognized consumptions rates.

Abstract: The invention relates to a disposable electronic diagnostic instrument designed for use in an Over-the-Counter (OTC) cholesterol test kit for measuring cholesterol levels of blood. The instrument is designed and calibrated specifically for use with diagnostic test strips supplied with the OTC cholesterol test kit.

Abstract: Concentration of a target chemical in the presence of other substances in a specimen is determined by subjecting the specimen to radio frequency electromagnetic components, sequentially or otherwise, ranging to about 5 GHz. The reflected and/or transmitted signal real and imaginary components at the specimen are spectrally examined as a function of frequency to identify the presence and/or concentration of the chemical of interest. Such examination includes analysis of the effective complex impedance presented by the specimen, and/or effective phase shift between the transmitted and reflected signal at the specimen. The effects upon glucose concentration measurements of varying electrolytes, primarily NaCl, can be nulled-out by examining impedance magnitude at a cross-over frequency, for example about 2.5 GHz. NaCl concentration exhibits a very linear relationship with phase shift change at frequencies in the 2 GHz-3 GHz range.

Abstract: The present invention relates to reagents and processes for the preparation of diagnostics which use a chromogenic redox detection system and whose chromogenic redox detection system essentially remains unaffected by interference from reducing. compounds in the sample material.

Abstract: A method for distinguishing between carbohydrates or glycoconjugates in a mixture thereof, wherein the or each carbohydrate or glycoconjugate is a hydrophilic fluorescently-labelled saccharide molecule, wherein the label is a --NR--Ph--CO-- group, wherein R is selected from H and substituents, and Ph is phenylene.

Abstract: The invention relates to a disposable electronic diagnostic instrument designed for use in an Over-the-Counter (OTC) cholesterol test kit for measuring cholesterol levels of blood. The instrument is designed and calibrated specifically for use with diagnostic test strips supplied with the OTC cholesterol test kit.

Abstract: The present invention is a method for the detection of hydrogen peroxide in biological fluids or an aqueous solution which involves contacting the solution with an oxidation-reduction indicator and a transition metal complex. The transition metal complex is either a creatinine coordinated with iron or a guanidine coordinated with iron.

Abstract: A method of noninvasive and in-vitro glucose and cholesterol concentration measurement employing nuclear magnetic resonance (NMR) spectroscopy is described. The measurement comprises a ratio formed by dividing the area of the resonance of the desired analyte, e.g., glucose or cholesterol, by the area of the water resonance in a spectrum of blood or tissue. In the in-vivo setting, the spectrum is obtained either in linkage with the pulsation of blood or by using a slice selection gradient such as that employed in the magnetic resonance imager. This measurement is then correlated to a traditional serum analyte concentration.

Abstract: The present invention relates to reagents and processes for the preparation of diagnostics which use a chromogenic redox detection system and whose chromogenic redox detection system essentially remains unaffected by interference from reducing compounds in the sample material.

Abstract: Methods of diagnosis of gestational diabetes mellitus are disclosed. In preferred embodiments, a blood sample is obtained from a pregnant female in the 24th to 28th week of pregnancy after an overnight fast, after a 1-hour 50-gram glucose challenge test, or at the 1-hour time point during a 3-hour 100-gram oral glucose tolerance test. The concentrations of fasting plasma glucose and glycosylated plasma proteins in this blood sample are then determined. A fasting plasma glucose concentration equal to or exceeding 90 mg/dL is 100% sensitive and 64% specific in predicting glucose-related macrosomia (i.e., birth weight above 4000 grams). A glycosylated plasma protein concentration equal to or exceeding 23% is 100% sensitive and 52% specific in predicting glucose-related macrosomia. A fasting plasma protein value equal to or exceeding 90 mg/dL and a glycosylated plasma protein value equal to or exceeding 23% is 100% sensitive and 93% specific in predicting glucose-related macrosomia.

Abstract: The inclusion of succinic acid or a salt thereof to stabilize compositions that include glucose oxidase and/or ferricyanide. Typically, the succinic acid or succinic acid salt is included in a diagnostic reagent utilized in test strips or test solutions useful for the analysis of glucose from a fluid sample.

Abstract: For determining 3-deoxyglucosone derivatives which are intermediate metabolites of the Maillard reaction in body fluids such as blood, urine, serum, plasma and the like in gas chromatography/mass spectrometry, .sup.13 C-labelled compounds or .sup.14 C-labelled compounds are useful as an internal standard substance. More specifically, 3-deoxyglucosone derivatives having the formula (I): ##STR1## wherein *C is .sup.13 C or .sup.14 C, X is O or N--OR wherein R is Me, Et or H, and Y is SiMe.sub.3 or SiMe.sub.2 tBu, and their production are provided. The measurement of 3-deoxyglucosone derivatives is useful in diagnosing diseases such as diabetes and diseases complicated with diabetes, including diabetic nephrosis, various renal disorders, renal insufficiency, metabolic diseases of carbohydrate and the like.

Abstract: A seal and wiper assembly covers the opening of a reservoir of buffer solution in a blood glucose level. A monitor. A replaceable test cap is designed for single use. As the test cap is installed, a clock starts to run. After a predetermined time, the clock disables the monitor. As the test cap is removed from the buffer, the assembly wipes the buffer from the glucose sensor.

Abstract: The present invention relates to polymeric luminophores which contain ruthenium, osmium, and rhenium complexes covalently attached to polymer matrices. The polymeric luminophores are capable of having their luminescence quenched by molecular oxygen and may be coated on optical fibers to form sensing elements to detect oxygen in gases and fluids.

Abstract: An improved method of testing individuals for diabetes, even if they have levels of interfering substances (e.g., uric acid, bilirubin, and glutathione) that would otherwise interfere with such testing, is disclosed. The individual's protein-bound glucose level and glucose level are compared to the analogous values for a reference population to enable the risk of that individual's having diabetes to be assessed. The substances that would otherwise tend to interfere with the assay for protein-bound glucose are removed before the assay, desirably by precipitating the protein-bound glucose using uranyl acetate, which desirably leaves substantially all of the interfering substances in the supernatant, then separating the precipitate from the supernatant, redissolving the precipitate, and conducting the colorimetric assay on the resulting solution. An improved colorimetric test for protein-bound glucose using viologens as the colorimetric electron acceptors is also disclosed.

Abstract: A system for determining the concentration of fructosamine in sera which consists of a first reagent in which a tetrazolium salt which reduces all reactive substances in sera including fructosamine and a second reagent which is responsive to all reactive substance in sera other than fructosamine. The difference in color change as between the two allows the determination of concentration of fructosamine.

Abstract: The invention relates to polymeric compositions useful in analyte determination. The compositions contain a polymer, a reagent system for analyte determination, and an extender. The last component alleviates tackiness in the composition, and thus reduces damage in preparation of test apparatus. Mica is the particularly preferred extender.

Abstract: The present invention is a method for assaying enzyme activity in a red blood sample. The method comprises these steps: (a) placing the following in a sample well: (1) a red blood sample containing an enzyme, (2) a substrate or substrates for the enzyme, (3) water, and (4) a buffer; (b) incubating the contents of the sample well for sufficient time and at sufficient temperature to allow for the formation of a fluorescent enzyme product should the enzyme be present in the red blood sample; (c) precipitating the hemoglobin; and (d) measuring the fluorescence of any fluorescent enzyme product formed in the sample well, directly from that sample well. The method of the invention may be used for assaying the activity of an enzyme, such as galactose-1-phosphate uridyl transferase (GALT) or biotinidase, in a red blood sample.

Abstract: A non-invasive glucose concentration measurement apparatus includes: a light source which projects at the sample radiation of a wavelength range including a wavelength at which absorption greatly changes with glucose concentration but does not greatly vary with temperature; a photosensor which receives the radiation which have been projected by the light source, and transmitted through or reflected by the sample, and generates an electrical signal corresponding to a through-transmitted or reflected level of the radiation of the wavelength; and a calculator which calculates a glucose concentration based on the electrical signal. A more accurate glucose concentration can be obtained without the influence of temperature.

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 source of high frequency electromagnetic radiation is coupled to a specimen containing a target chemical whose presence and/or concentration is to be ascertained. Preferably the source radiation includes a plurality of high frequency spectra, at least one of which encourages energy transfer with the chemical of interest. The source radiation is coupled to the specimen via a probe pair that is also used to access a return signal representing an interaction between the source signal and the specimen. The return signal is processed to yield a spectral signature correlating to the target chemical and/or its concentration. Preferably signal processing compares frequency spectra within the source signal to spectra within a sampled return signal. The sampled return signal is a signal obtained by sampling a return signal at the probe pair and by sampling the response to the source signal of a circuit that electrically approximates the specimen.

Abstract: A method is provided for determining glucose-6-phosphate, including the step of dehydrogenating glucose-6-phosphate and NAD or NADP in the presence of glucose-6-phosphate dehydrogenase to produce 6-phosphogluconate and NADH or NADPH, wherein the determination is carried out in the presence of 6-phosphogluconolactonase. Also provided is a composition for determining glucose-6-phosphate, characterized by containing 6-phosphogluconolactonase, glucose-6-phosphate dehydrogenase, and NAD or NADP.

Abstract: A device for measuring the ingredients in liquid, primarily a body fluid. A valve has a reservoir composed of a communicating hole in the valve and a cell which is able to communicate with the reservoir. The cell may be connected with an inlet for a diluent through the reservoir and has a sensor and a stirrer. It is possible to measure the ingredients with accuracy and to realize a continuous monitoring thereof.

Abstract: A composition for detecting or quantitatively measuring a peroxide active material in a sample, containing an organic hydroperoxide, a chromogen, and an iron (111) complex of the formula: [(OOC-X-COO).sub.3 Fe]M.sub.3 in which X is an alkylene group:-(CH.sub.2).sub.n - (n=0-5) or an allyl group, and M is a monovalent cation, which can eliminate the influence of reducing compounds such as ascorbic acid contained in the sample.

Abstract: Described are control reagents useful in analyte determination. The reagents contain a known concentration or amount of the analyte to be assayed, and a polymer. The polymer is made up of monomers of either water soluble acrylic monomers, water soluble quaternary amines, or mixtures of these two types of molecules. Various control reagent formulations, as well as new polymers useful in control reagents, are disclosed.

Abstract: An improved screening test method and kit for cancerous and precancerous conditions which is rapid, employs reagents which can be provided in kit form and which does not give false negatives due to sampling error, immobilizes a sample of a proteinaceous body fluid in a membrane filter, tests for marker carbohydrates therein which have vicinal galactose moieties and which are enzymatically oxidized with galactose oxidase to vicinal aldehydic moieties which then visualizes any thus-produced vicinal aldehydic moieties with Schiff's Reagent, then further oxidizes those samples which test negative for the marker carbohydrates with periodic acid, thereby rendering the sample visualizable with Schiff's Reagent if the sample contains glycoprotein, which applies the galactose oxidase directly to the membrane filter, thereby speeding up color developed, and employs Schiff's Reagent which was refrigerated after preparation until its color faded to a straw shade before being treated with activated charcoal, which treatme

Abstract: A method for quantifying glucose concentration in blood, body fluids, and other samples within, below and above the normal physiological range, which relies on non-radiative fluorescence resonance energy transfer, as well as devices useful in quantifying blood glucose concentration using the present method.

Abstract: A system for determining the concentration of fructosamine in sera which consists of a first reagent in which a tetrazolium salt which reduces all reactive substances in sera including fructosamine and a second reagent which is responsive to all reactive substance in sera other than fructosamine. The difference in color change as between the two allows the determination of concentration of fructosamine.

Abstract: A method for measurement of fructosamines in an aqueous liquid characterized by including the steps of:(a) bringing an aqueous liquid sample into contact with one or more active oxygen producing substances;(b) bringing the product of said step (a) into contact with a reagent producing a detectable change in the presence of hydrogen peroxide derived from the active oxygen, and(c) detecting an occurrence of the detectable change of said step (b).

Abstract: A method for determining the presence of an analyte in a fluid is described along with various components of an apparatus specifically designed to carry out the method. The method involves taking a reflectance reading from one surface of an inert porous matrix impregnated with a reagent that will interact with the analyte to produce a light-absorbing reaction product when the fluid being analyzed is applied to another surface and migrates through the matrix to the surface being read. Reflectance measurements are made at two separate wavelengths in order to eliminate interferences, and a timing circuit is triggered by an initial decrease in reflectance by the wetting of the surface whose reflectance is being measured by the fluid which passes through the inert matrix. Repeatability is insured by a normalization technique performed on the light source before each reading, and an alignment method operated on the reagent strip prior to emplacement on the apparatus.

Abstract: Control reagents an oxidant or a hydroxylamine compound together with other ingredients, the most important of which is a known amount of the analyte for which the reagent acts as a control.

Abstract: A portable blood chemistry monitoring meter that employs an analog circuit in conjunction with a manually adjustable potentiometer to locate a null position that balances the measure taken of the blood chemistry-induced changes in the chemistries of disposable test strips. The meter displays in pre-printed, man-readable format blood chemistry concentrations that are individually calibrated to the specific batch-lot chemistries of the disposable test strips used with the meter. In a preferred embodiment, the meter is a blood glucose monitoring meter.