Abstract: Optical sensor formulations comprising polymeric sensing formulations and methods of predictably making optical sensor formulations, for, e.g., measuring O2 levels in patient blood samples. These formulations may be, e.g., deposited as a membrane on light-transmissive substrates. In an embodiment, O2-sensing formulations may be made by a process including selecting a first homopolymer comprised of first monomeric units, the first homopolymer having a first PermO2 value; selecting a second homopolymer comprised of second monomeric units, the second homopolymer having a second PermO2 value that is different from the first PermO2 value; and copolymerizing the first and second monomeric units to obtain a copolymer having an intermediate PermO2 value, i.e., between the two PermO2 values, the intermediate PermO2 providing the desired PermO2 for the desired oxygen sensing formulation.

Abstract: A control or calibration standard for use with instruments for the optical measurement of the hemoglobin content in blood samples, features scattering particles or beads dispersed in aqueous electrolyte solution. To prevent sedimentation of the beads during storage, they have a mean diameter of <0.6 &mgr;m, preferably about 0.3 &mgr;m, and a volume concentration of <1%, preferably <0.3%. To prevent long term agglomeration, a non-ionic surfactant with an added antioxidant can be included in the formulation.

Abstract: Multi-analyte reference solutions having a stable partial pressure of oxygen (pO.sub.2) in zero headspace packaging and methods for preparing such solutions are disclosed. The solutions have long shelf and use lives when stored at room temperature and are packaged in laminated foil containers having low or no oxygen reactivity. Access devices are also disclosed.

Abstract: In a method of optically determining the total hemoglobin concentration (tHb) in non-hemolyzed whole blood, using at least two wavelengths for measuring, a first wavelength of .lambda.<805 nm and a second wavelength of .lambda.>805 nm is employed, such that the following is valid for the absorption coefficients of the hemoglobin derivatives O.sub.2 Hb and RHb at the two measurement wavelengths .lambda..sub.1 and .lambda..sub.2 : .sigma.O(.lambda..sub.1).about..sigma.R(.lambda..sub.2) and .sigma.R(.lambda..sub.1).about..sigma.O(.lambda..sub.2). The sum of absorption values A.sub.1 and A.sub.2 measured at wavelengths .lambda..sub.1 and .lambda..sub.2 will be a quantity which is proportional to the total hemoglobin concentration tHb and independent of the oxygen saturation O.sub.2sat.

Abstract: A cassette useful for measuring one or more parameters of blood in, for example, a cardiopulmonary bypass circuit has a convex coupling for releasable connection with a mating, concave coupling of a measuring device. The coupling of the cassette includes flexible leg portions that can be moved toward each other under the influence of finger pressure to detach the cassette from the measuring device. Optionally, the cassette includes a body carrying one or more sensors, and also includes a casing that can be detached from the body when desired. A shunt circuit arrangement enables the cassette to be connected to the bypass circuit either before or during a surgical procedure.

Abstract: A method and system for controlling the concentration of one or more gaseous species of interest in a fluid reference medium throughout a range of temperatures in which a temperature related, dominant independent source of the gaseous species of interest is used to control the partial pressure of one or more gaseous species of interest contained in the reference medium in a manner such that the concentration of the gaseous species of interest in the reference medium is controlled as a predetermined, normally generally linear, function of temperature, f(T), over the temperature range. The source of the one or more gaseous species of interest is a separate reservoir containing an amount of a formulated temperature sensitive source of the one or more gaseous species of interest. The reference medium and the reservoir are contained in separate liquid-tight, gas-permeable enclosures contained in a common substantially gas-tight enclosure.

Abstract: The present invention relates to a method and apparatus for determining blood oxygen transport, and to measure lipid levels by correlating these levels with the rate at which oxygen diffuses through the red blood cell membrane.

Abstract: In a method for flushing and calibrating at least one sensor in a system for body fluid analysis, said system having a first container, connected to the sensor, holding a first flushing liquid, and a second container, connected to the sensor, holding a second flushing liquid, the flushing liquids having different analytic contents, a calibration measurement is performed with one of the flushing liquids before every body fluid analysis determination, with the different flushing liquids being used alternatively according to a predetermined pattern. The pattern is governed by certain criteria or a combination thereof.

Abstract: A cassette for tonometric calibration especially useful for systems that measure one or more blood parameters includes a cassette having an elongated fluid chamber. In one embodiment of the invention, the fluid chamber includes an expansion region that reduces the likelihood of bubble coalescence of the calibration gas. In another embodiment, inner wall sections of the chamber are provided with a hydrophilic surface. Optionally, a fitting is non-releasably coupled to a casing of the cassette and is movable between a first position for closing a calibration gas outlet port and a second position for venting the calibration gas outlet port. In another embodiment, the cassette includes an elongated sparging tube that extends in a direction generally parallel to the longitudinal axis of the chamber.

Abstract: A method of measuring microbial activity of microbes in real time includes preparing a medium to enable microbial activity and placing the medium in operative contact with an appropriate sensor. The sensor is scanned to provide measurement electrical signals representative of position and amount of microbial activity, the sensor being responsive to a by-product of the microbial activity, such as a change in pH. The measurement signals can then be processed to provide a visual image display, and the display can visually distinguish between levels of pH activity and coordinate positions of the microbial activity.

Abstract: A cartridge assembly is provided for analyzing characteristics of a sample fluid. The cartridge assembly comprises an assembly body having a passageway, a cavity and, interposed between the passageway and the cavity, a manifold containing a port that serves as a feedthrough between the cavity and the passageway. The passageway forms a flow path through which the sample is drawn. The cartridge assembly also comprises a sensor responsive to a characteristic of the sample fluid. The sensor is housed in the assembly body cavity and is in communication with the passageway by way of the port in the manifold. Optionally, the cartridge assembly includes a temperature monitoring means and a heating means in thermal communication with the passageway. In addition, a method is provided in which the cartridge assembly is used for analyzing a characteristic of a sample. A bedside system for monitoring characteristics of a physiologic fluid comprising the cartridge assembly is provided as well.

Abstract: The invention relates to a measuring process, the purpose of which is to increase the measuring accuracy of pulse oxymeters and comparable optical devices which are used in vivo to ascertain oxygen saturation of arterial blood. The measuring process according to the invention is provided for the purpose of ascertaining oxygenation of arterial blood in tissue by evaluating the differential light attenuation at several wavelengths. It is characterized by the fact that light attentuation of at least one wavelength is determined in order to choose those calibration curves of several variables (.OMEGA.1, .OMEGA.2. . . .) produced by different wavelength pairings with a minimized error in order to generate an output signal for the arterial blood oxygenation.

Abstract: A method and an equipment for determining components, particularly pH, pO.sub.2 and pCO.sub.2 in blood. In order to facilitate the determination of blood gases, one sensor is used for measurement of more than one component. The components are measured at the same measuring point, using an electrode based on antimony. The electrode potential is measured both with and without a known voltage applied over the electrode.

Abstract: Tests for elevated pH and volatile amines in aqueous fluids are disclosed, including tests useful in the diagnosis of bacterial vaginosis and in other biological conditions. By using formulated indicators and indicators held in matrices that are permeable to gas but not to liquid, the tests provide clear and sharp transitions detectable by visual or machine-readable means rather than by subjective judgments such as small gradations in color or olfactory determinations. The tests lend themselves readily to iconic readouts of the test indications and to the inclusion of positive and negative controls.

Abstract: Disclosed are oxygen concentration and/or pressure sensing devices and methods which incorporate photoluminescent silica aerogels. Disclosed sensors include a light proof housing for holding the photoluminescent aerogel, a source of excitation radiation (e.g., a UV source), a detector for detecting radiation emitted by the aerogel, a system for delivering a sample gas to the aerogel, and a thermocouple. Also disclosed are water resistant oxygen sensors having a photoluminescent aerogel coated with a hydrophobic material.

Abstract: Non-invasive methods have been developed for the measurement of NO levels in a variety of fluid media, e.g., body fluids. The present invention embraces the use of a semi-permeable vessel wherein said vessel contains an NO reacting substance to trap NO diffusing thereinto, and a simple physical or chemical detection method to measure the levels of the end products. Since NO is a neutral gas molecule, it is capable of diffusing freely across a wide range of biocompatible polymer membranes which exhibit a high permeability to NO and other neutral gas molecules, such as O.sub.2 and CO.sub.2, but which are not permeable to charged molecules, such as NO.sub.3.sup.- or NO.sub.2.sup.-. The latter two compounds are ubiquitously present in body fluids and often interfere with the measurement of NO levels. The permeability of selected membranes to NO, but not to NO.sub.3.sup.- or NO.sub.2.sup.

Abstract: The present invention provides an optical fluorescence based sensor for measuring the concentration of a gas (e.g., CO.sub.2 or ammonia) in a medium such as blood which has improved drift stability. In a preferred embodiment, the sensors of the present invention comprise microcompartments of an aqueous phase having a pH sensitive sensing component within a hydrophobic barrier phase. The sensors of the present invention are substantially free of partitioning species other than the analyte of interest which can migrate from one phase to the other in response to a change in pH in the aqueous phase and which substantially affect the concentration dependent signal. In an alternative embodiment, the sensors of the present invention are constructed so as to retard the migration of partitioning species, thus reducing the initial rate of drift.

Abstract: The invention provides compounds which specifically inhibit factor Xa activity. The compounds consist of the structure X.sub.1 -YIR-X.sub.2, wherein X.sub.1 is H, acyl, alkyl, acylalkyl, arylalkyl or one or more amino acids, and X.sub.2 is a modified C-terminal group, one or more carboxy-protecting groups or one or more amino acids or other substituent, and Y, I and R are tyrosine, isoleucine and arginine, respectively, or peptidomimetic or organic structures that possess the same functional activity as Y, I and R, respectively. In addition, the present invention provides a compound having the structure A1-A2-(A3).sub.m --B, where m is 0 or 1. A compound of the invention can be linear or cyclic and can be about 2 and 43 residues in length. A compound of the invention is characterized, in part, in that it exhibits a specific inhibition of factor Xa activity with a K.sub.i of .ltoreq.100 .mu.M, preferably .ltoreq.

Abstract: The invention relates to a measurement apparatus (1) for analysing fluids, comprising a container (3) in the form of a syringe, into which a fluid may be taken in via an intake device (14) through at least one opening (5), and further comprising a sensor (7) which is either integrated in the container wall (9) or is attached to said container wall (9), the sensor(s) (7) being so disposed that it/they can come into contact with the fluid which may be taken up into the cavity (10).

Abstract: Physico-chemical parameters, such as pH, pO.sub.2, pCO.sub.2, % O.sub.2, sat, etc., are determined with the use of a sensitive medium, such as a chromophore, having at least one optical property the profile of the spectrum whereof over a predetermined wavelength spectrum of optical radiation varies as a function of the parameter to be determined. The profile of the spectrum is analysed, for example by means of polychromatic sensor means acting on the medium's spectrum, which is preferably substantially continuous, so as to enable the analysis to be carried out with the aid of a profile-recognition function by typical pattern-recognition operations. The determination is thus rendered largely independent of numerous perturbing factors such as those resulting from the use of partially disposable monitoring units, thus eliminating the need for calibration steps.

Abstract: Methods and apparatus for the measurement of oxygen, pH and CO.sub.2 in human and animal tissue is provided, in which the compounds preferably include a chromophore and/or fluorphor capable of absorbing an amount of energy and subsequently releasing the energy as phosphorescent and/or fluorescent light, and wherein the phosphorescence is quenched by molecular oxygen according to the Stern-Volmer relationship, CO.sub.2 is measured by fluorphor which alters fluorescence with pH.

Abstract: A method is taught by which a sample can be analyzed for the selective determination of the total concentration of bilirubin (B.sub.t), the concentration of conjugated bilirubin (B.sub.c), the concentration of unconjugated bilirubin (B.sub.u), the concentration of unbound bilirubin (b), the concentration of unbound, unconjugated bilirubin (b.sub.u) using a unique combination of enzymatic and colorimetric methods in a single assay, so that the potentially neurotoxic, non-albumin bound, unconjugated fraction of total bilirubin in the sample (i.e., b.sub.u) can be measured in a simple, quick and accurate manner. A kit utilizing the same assay is also described. Both kit and methods will be of use to the clinician and general researcher. The B.sub.t, B.sup.c, B.sub.u, b and b.sub.u are determined using spectra, absorption or emission characteristics in combination with kinetic measurements of rates of reaction of chemical processes.

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 "reagentless" chemiluminescent biosensor and method for the determination of hydrogen peroxide, ethanol and D-glucose in water. An aqueous stream is basified by passing it through a solid phase base bed. Luminol is then dissolved in the basified effluent at a controlled rate. Oxidation of the luminol is catalyzed by the target chemical to produce emitted light. The intensity of the emitted light is detected as a measure of the target chemical concentration in the aqueous stream. The emitted light can be transmitted by a fiber optic bundle to a remote location from the aqueous stream for a remote reading of the target chemical concentration.

Abstract: An apparatus and method of equilibrating the dissolved gas composition of an aqueous fluid to reflect the predetermined gas composition contained in a gas equilibration reservoir. The equilibrated aqueous fluid can be used in a method of determining the concentration of a dissolved gas in a fluid sample. In one embodiment, the method is used to control the equilibrated gas composition of a calibrant fluid which, in turn, is used to measure the concentration of a dissolved gas, such as oxygen and carbon dioxide, in a sample fluid, such as whole blood.

Abstract: A novel flexible package for an oxygen reference solution has been developed. This package is made from a laminated film including preferably polypropylene as the inner layer, aluminum foil as the middle layer, and polyester as the outer layer. The seams are heat sealed, while an optional access device for allowing access to the solution after the storage period, is attached to the inside wall of the bag without breeching the middle barrier layer.

Abstract: In a method of optically determining the total hemoglobin concentration (tHb) in non-hemolyzed whole blood, using at least two wavelengths for measuring, a first wavelength of .lambda.<805 nm and a second wavelength of .lambda.>805 nm is employed, such the following is valid for the absorption coefficients of hemoglobin derivatives O.sub.2 Hb and RHb at the two measurement wavelengths .lambda..sub.1 and .lambda..sub.2 : .sigma.O(.lambda..sub.1).about..sigma.R(.lambda..sub.2) and .sigma.R(.lambda..sub.1).about..sigma.O(.lambda..sub.2). The sum of absorption values A.sub.1 and A.sub.2 measured at wavelengths .lambda..sub.1 and .lambda..sub.2 will be a quantity which is proportional to the total hemoglobin concentration tHb and independent of the oxygen saturation O.sub.2sat.

Abstract: The invention is directed to a measuring method for determining the concentration of a gas in a measurement sample with the aid of a combined measuring apparatus. The measuring apparatus includes a first infrared optical gas analyzer 1 as well as a second gas analyzer 2, which contains an electrochemical measuring cell 13. The measuring result of the electrochemical measuring cell 13 functions to correct the concentration, which is determined by the infrared optical gas analyzer 1, when the infrared optical reference measurement has already been performed on a measurement sample with this measuring sample not being free of the substance to be detected.

Abstract: A stable single reagent for the determination of carbon dioxide in serum is provided as an aqueous solution of diagnostically amounts and NADH and/or NADPH, and a stabilizing system therefore reactively stabilized PEPC and a substrate for reacting with bicarbonate ion under alkaline conditions in the presence of PEPC.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: The present invention provides a method and apparatus for rapid measurement of a fluid bulk analyte, requiring only microscale volumes. Several fluid bulk analytes can be measured simultaneously and, for biological samples, the cell content can also be measured simultaneously. The invention comprises reporter beads for chemical analysis of fluid bulk properties such as pH, oxygen saturation and ion content. Each reporter bead comprises a substrate bead having a plurality of at least one type of fluorescent reporter molecules immobilized thereon. The fluorescent properties of the reporter bead are sensitive to a corresponding analyte. Reporter beads are added to a fluid sample and the analyte concentration is determined by measuring fluorescence of individual beads, for example in a flow cytometer. Alternatively, reporter molecules which change absorbance as a function of analyte concentration can be employed.

Abstract: The invention provides a diagnostic method of determining Rh genotypes by the identification of the molecular basis of Rh polymorphisms. Specifically, the invention provides a method for directly determining Dd and associated CcEe genotypes with great accuracy, overcoming problems associated with traditional serologic typing methods and leading to a direct discrimination of D/D, D/d, and d/d genetic status. The diagnostic method allows genotyping of fetuses to assess the risk of hemolytic diseases caused by Rh alloimmunization and genetic counseling and/or testing of couples to predict the outcome of pregnancies in relation to Rh incompatibilities. The method of the invention preferably employs amplification of Rh nucleic acid sequences, and employs differential cleavage of RhD-, RhCc- and/or RhEe-specific nucleic acid sequences by a restriction enzyme. Furthermore, diagnostic kits for the determination of Rh genotypes are provided.

Abstract: A system for real time, breath by breath sampling of a patient receiving up to 100 percent oxygen to determine nutritional requirements of the patient through indirect calorimetry includes a pneumotach member for measuring the volume rate of flow of inspired and expired gas flow at the patient/endotracheal tube/ventilator connection. A sample line extends from the pneumotach to a gas analyzer which measures the percent concentration of constituent respiratory gases in the expired gas flow. A flowmeter is coupled to the gas analyzer for determining the volume flow rate of the expiratory gas flow through the sample line. A microprocessor control samples the analog electrical signals from the gas analyzer, the flow meter and the pneumotach in a predetermined sequence, dynamically compensating for variations in gas flow rate.

Abstract: A method is provided-for manufacturing a fiber optic sensor for detecting or measuring a parameter of interest in a sample fluid, including pH, concentration of dissolved gases such as O.sub.2 or CO.sub.2, and the like. The sensing chemistry is affixed to the distal end of an elongated optical fiber by way of an adhesive layer typically comprised of an acrylic adhesive composition. Novel optical sensors, fabricated using the aforementioned method, are provided as well.

Abstract: A method for determining pH or pCO.sub.2 using luminescent lifetimes and energy transfer in which an energy transfer donor-acceptor pair is exposed to a sample to be analyzed, the donor of the donor-acceptor pair being photoluminescent and the acceptor of the donor-acceptor pair being sensitive to the pH or pCO.sub.2 of the sample. One or both of the donor-acceptor pair may be bound to a carrier. The sample is irradiated and the resultant emission detected. By measuring the apparent luminescent lifetime, the pH or pCO.sub.2 of the sample can be determined.

Abstract: A flow through cell for non-invasive monitoring of fluids flowing therethrough includes a membrane covered view window through which sensors may monitor the fluids. The membranes are secured in position by a frame and retainer assembly with the frame and retainer clamping the membranes in place between the frame support structure and the retainer. The frame is snugly fitted into the cell and includes a sensor receptive chamber for positioning the sensors in the window and in position with the membranes.

Abstract: A method of determining the total carbon dioxide concentration in plasma (TCO.sub.2 plasma) directly from a whole blood sample involves adjusting total carbon dioxide concentration measured in the whole blood sample (TCO.sub.2 whole blood) using a volume dilution factor (VDF) to give a value that is equivalent to TCO.sub.2 plasma.

Abstract: A system and method in which a photoluminescent ligand is added to a sample to be analyzed in the form of a photoluminescent probe having intrinsic analyte-induced lifetime changes. The method preferably employs phase-modulation fluorometry to measure the lifetime changes. Specific probes are disclosed for measuring various analytes, particularly ionic solutes, including H.sup.+, Ca.sup.2+ and K.sup.+.

Abstract: Disclosed is an apparatus and method of equilibrating the dissolved gas composition of an aqueous fluid to reflect the predetermined gas composition contained in a gas equilibration reservoir. The equilibrated aqueous fluid can be used in a method of determining the concentration of a dissolved gas in a fluid sample. In one embodiment, the disclosed method is used to control the equilibrated gas composition of a calibrant fluid which, in turn, is used to measure the concentration of a dissolved gas, such as oxygen and carbon dioxide, in a sample fluid, such as whole blood.

Abstract: Disclosed is an apparatus and method of equilibrating the dissolved gas composition of an aqueous fluid to reflect the predetermined gas composition contained in a gas equilibration reservoir. The equilibrated aqueous fluid can be used in a method of determining the concentration of a dissolved gas in a fluid sample. In one embodiment, the disclosed method is used to control the equilibrated gas composition of a calibrant fluid which, in turn, is used to measure the concentration of a dissolved gas, such as oxygen and carbon dioxide, in a sample fluid, such as whole blood.

Abstract: A fiber optic sensor for measurement of in vivo nitric oxide concentrations in a subject. The sensor contains a nitric oxide-sensing compound in a polymer matrix attached to an optical fiber. The sensor may be placed in any blood vessel, including one within the heart of a subject for continuous measurement of nitric oxide concentrations in blood.

Abstract: A CO.sub.2 electrode can be calibrated with two PCO.sub.2 calibration standard solutions having known pH values and known bicarbonate ion source concentrations. An O.sub.2 electrode can be calibrated using air as one calibration standard and a solution containing an excess of an O.sub.2 depleting agent as a second calibration standard.

Abstract: A blood analyzer includes a display means that visually informs operating room personnel of the instantaneous condition of a patient's blood. Arterial or central venous tubing connects the analyzer to a blood vessel, either arterial, venous, or both, of the patient. In a first embodiment, a plurality of sensor means are positioned within a primary chamber of the analyzer. In a second embodiment, a secondary chamber in valved fluid communication with the primary chamber enables introduction of blood thereinto and a port is provided for entry of a syringe needle so that reactants may be introduced into the secondary chamber so that an additional test may be performed. In a third embodiment, the primary chamber is in valved fluid communication with a conventional pressure transducer.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

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 method of photometric in vitro determination of at least one blood gas parameter in a sample of whole blood. The whole blood sample is obtained by connecting an at least partially transparent sample container to an in vivo locality and transferring whole blood into the sample container, then breaking the connection. The sample container is arranged in an optical system which has a radiation source and a means for detecting radiation to locate the sample container between the radiation source and the radiation detection means. Radiation is transmitted to the sample from the radiation source and radiation emitted from the sample is transmitted to the radiation detection means. The detected radiation is used to determine the blood gas parameter of the sample. A system for use in this method has a radiation source, a radiation detection means, an at least partially transparent sample container, and a sample container station.

Abstract: Aqueous solutions containing buffers and electrolytes are adjusted to levels required for calibration of both blood gas analyzers and ion selective electrolyte analyzers. A control material, composed of similar matrix, is adjusted to three levels of blood gas and electrolyte conditions. These quality control materials are used to monitor blood gas/electrolyte laboratory instrumentation.

Abstract: Sensing elements, useful in sensing the concentration of a gas, e.g., carbon dioxide, in a medium, e.g. blood, and methods for making such sensing elements are disclosed. In one embodiment, the method comprises continuously placing a sensing composition precursor in contact with a continuous web, forming a continuous sensing composition from the precursor, and applying a continuous opaque film to the sensing composition. A plurality of individual sensing elements are formed from this composite structure. These sensing elements, which each have very similar sensing characteristics, are placed in a sensor fixture for use.

Abstract: A sensor for measuring the concentration of an analyte in a medium is disclosed. In one embodiment, the sensor comprises a sensing element including a matrix material and, covalently bonded thereto, one or more monomeric indicator components each of which is capable of providing a first emitted signal of a given wavelength in response to being exposed to an excitation signal. The sensing element is capable of providing a second emitted signal having a longer wavelength than the first emitted signal or signals in response to being exposed to the excitation signal, the second emitted signal being provided by an excimer component produced in the sensing element from the monomeric indicator component(s) and being dependent on the concentration of the analyte in the medium to a greater extent than the first emitted signal or signals.

Abstract: A sensor device is disclosed for identification of a gaseous component in a gaseous or liquid sample. The sensor device comprises an optode membrane having sensitivity for the gaseous component to be identified. The optode membrane incorporates two ionophores, at least one of which is a chromoionophore capable of changing absorption spectrum. The sensor device further comprises a hydrophobic gas-permeable membrane, one side of which is positioned upon the optode membrane to prevent direct contact of the optode membrane with the liquid or gaseous sample while still permitting passage of the gaseous component to be identified. As a result, ionic compounds incapable of passing through the lipophilic gas-permeable membrane do not interfere with the identification process leading to a highly sensitive sensor.