Abstract: A device for assessing capillary vitality comprises an inflatable cuff, a blood flow sensor and a pressure sensor in communication with the cuff, a pressure instrument in fluid communication with the cuff for inflation and deflation thereof, a microprocessor coupled to the pressure instrument for controlling airflow, at least one metabolic sensor for measuring a metabolic condition, and a computer program executable by the microprocessor. The pressure instrument includes a source of pressurized air and a conduit connecting the source of pressurized air to the cuff. The microprocessor is arranged to receive inputs from the blood flow, pressure and metabolic sensors.

Abstract: There is a need within the medical community for non-invasive instruments to measure critical physiologic parameters at the point of care. Such a technique may be applicable to a wide variety of commonly monitored physiologic parameters during critical care patient management. The invention is directed to a method of measuring the pH of a patient's tissue. The method includes measuring the optical signal from a specie whose fluorescence is pH sensitive, such as nicotinamide adenine dinucleotide (NADH) and also measuring the optical signal from a second biological marker, such as FAD, the fluorescence from the second marker being substantially insensitive to pH. The method includes determining the patient's pH by using the first and second optical signals.

Abstract: There is a need for a technique to compensate for, or eliminate, motion-induced artifacts in patient-attached critical care monitoring instruments. Consequently, the invention is directed to improving pulse-oximetry by incorporating additional signals to aid in the triggering of the pulse-oximeter or in analyzing the data received by the pulse oximeter. This includes detecting when the patient moves and analyzing the pulse-oximetry data in light of the detected movement.

Abstract: The present invention discloses novel polymer compositions comprising cellulose acrylamide, acrylamide and/or a fluorescent indicator species, and membranes made with these compositions. Optical pH sensors for monitoring the pH in a fluid sample, and methods for making such pH sensors are also disclosed. The pH sensors have reduced sensitivity to sample components that can interfere with pH measurements.

Abstract: A system for characterizing coatings and substrates of a material under test. A sensor is positioned against a coated sample which is to be measured to obtain phase and magnitude measurements. Penetration depth of the magnetic waves of the sensor is a function of frequency. Measurements are made at each of a plurality of signal frequencies. The measured phase and magnitude data is applied with respect to a frequency independent parameter, such as conductivity, using a grid method. The conductivities of the coating and the substrate are determined by the limits of conductivity with respect to frequency. With the assumed conductivities of the coating and substrate, the sensor is once again placed over the material, and coating thickness and lift-off are determined. By examining the coating thickness versus frequency the accuracy of the measurement can be determined, since actual coating thickness does not vary with frequency in the material.

Abstract: A method for making a fiber optic sensor includes the steps of applying an adhesive composition to the distal end of an optical fiber, and applying a solution containing a copolymer of (a) a cellulose acrylamide, (b) an acrylamide, and (c) a copolymerizable monomeric fluorescent indicator species thereto to form a sensing layer.

Abstract: The present invention discloses novel polymer compositions comprising cellulose acrylamide, acrylamide and/or a fluorescent indicator species, and membranes made with these compositions. Optical pH sensors for monitoring the pH in a fluid sample, and methods for making such pH sensors are also disclosed. The pH sensors have reduced sensitivity to sample components that can interfere with pH measurements.

Abstract: A method is provided for calibrating sensors used to analyze characteristics of physiologic fluids such as blood. The method involves the use of a sensor assembly having an analyte-responsive sensor in communication with a passageway which is in divertable fluid communication with a physiologic line and a conduit by which a reference sample may be introduced into the passageway. The method involves exposing the sensor to the reference sample, thereby producing a sensor response. The method also allows performing quality control on the sensors. Also provided is an apparatus with which the claimed method may be practiced.

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: 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 ratiometric optical sensors method of making is provided to measure dissolved oxygen in a fluid sample. The sensor is formulated so as to contain an oxygen permeable membrane of a cured perfluorinated urethane polymer and, incorporated therein, an oxygen-sensitive indicator component and a reference dye component. The emission spectrum from the indicator component is calibrated by comparison with that of the reference dye, which is substantially less sensitive to oxygen-quenching and which has a photodecomposition rate similar to the indicator component. Methods for making and using the membrane and sensor are provided as well.

Abstract: A method is provided for manufacturing a fiber optic sensor for detecting or measuring the concentration of carbon dioxide in a sample fluid. The method involves incorporation of a fluorescent indicator composition in a silicone capsule slidably arranged over the tip of a fiber optic, sealed with a suitable adhesive. To amplify the detectable signal obtained, the capsule is preferably fabricated so as to contain reflective particles, and tapers to a narrow tip. Novel optical sensors, manufactured using the aforementioned method, are provided as well.

Abstract: A fiber optic sensing device for measuring a chemical or physiological parameter of a body fluid or tissue is provided. To one end of the fiber is attached a polymer including a plurality of photoactive moieties selected from the group consisting of chromophores and lumophores, the photoactive moieties spaced apart so as to minimize chemical or physical interaction therebetween while optimizing the density of photoactive moieties. In one embodiment, a polymer chain is covalently bound to photoactive moieties through functional groups such as esters, amides, or the like. In a second embodiment, a polymer chain is inherently fluorescent and is formed from at least one monomeric unit. These devices are particularly useful as pH and oxygen sensors.

Abstract: A method is provided for calibrating sensors used to analyze characteristics of physiologic fluids such as blood. The method involves the use of a sensor assembly having an analyte-responsive sensor in communication with a passageway which is in divertable fluid communication with a physiologic line and a conduit by which a reference sample may be introduced into the passageway. The method involves exposing the sensor to the reference sample, thereby producing a sensor response. The method also allows performing quality control on the sensors. Also provided is an apparatus with which the claimed method may be practiced.

Abstract: A device is provided for maintaining a volume of gas dissolved in a fluid at a predetermined partial pressure. The device includes a first sealable, gas-tight pouch containing the fluid and a second sealable, gas-tight pouch encasing the first pouch and providing a space between the first and second pouches. The space may be charged with an atmosphere containing a volume of the gas dissolved in the fluid that is greater than the volume of dissolved gas, at a partial pressure that is substantially the same as the partial pressure of the dissolved gas. A method is also provided for using the device to maintain a volume of a gas dissolved in a fluid at a predetermined partial pressure.

Abstract: A ratiometric method for using optical sensors is provided to measure dissolved oxygen in a fluid sample. The sensor is formulated so as to contain an oxygen permeable membrane of a cured perfluorinated urethane polymer and, incorporated therein, an oxygen-sensitive indicator component and a reference dye component. The emission spectrum from the indicator component is calibrated by comparison with that of the reference dye, which is substantially less sensitive to oxygen-quenching and which has a photodecomposition rate similar to the indicator component. Methods for making and using the membrane and sensor are provided as well.

Abstract: A simultaneous dual excitation/single emission ratiometric method using fiber optic sensors is provided for detecting or measuring a parameter of interest in a sample, including pH, concentration of gases such as CO.sub.2, and the like. The method involves simultaneously providing modulated optical light corresponding to first and second regions of an indicator species' absorption or excitation spectrum, detecting modulated emission signals from the indicator species, demodulating the emission signals, calculating the apparent quantity of analyte present in the sample from the indicator emission signals and correcting the apparent quantity of analyte present for variations resulting from external factors, by determining the ratio of the demodulated indicator emission signals. An apparatus is provided for performing the method as well.

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 ratiometric method for using optical sensors is provided to measure dissolved oxygen in a fluid sample. The sensor is formulated so as to contain an oxygen permeable membrane of a cured perfluorinated urethane polymer and, incorporated therein, an oxygen-sensitive indicator component and a reference dye component. The emission spectrum from the indicator component is calibrated by comparison with that of the reference dye, which is substantially less sensitive to oxygen-quenching and which has a photodecomposition rate similar to the indicator component. Methods for making and using the membrane and sensor are provided as well.

Abstract: An optical sensor is provided for measuring dissolved gases such as O.sub.2 or CO.sub.2 in a fluid sample. The sensor is formulated so as to contain a gas permeable membrane of a cured perfluorinated urethane polymer and, incorporated therein, a gas-sensitive indicator component. Methods for making and using the membrane and sensor are provided as well.