Abstract:
A device (10) is provided for minimizing outgassing of a gas dissolved in a fluid at a predetermined partial pressure. The device includes a first pouch (12) containing the fluid (18) and a compressing means (14, 42, 42', 52, 52') for subjecting the first pouch to greater-than-ambient pressure. Methods are also provided for using the device to minimize outgassing.
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 CO2, 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 O2 or CO2, and the like. The sensing chemistry (20) is affixed to the distal end of an elongated optical fiber device (10) by way of an adhesive layer (16) typically comprised of an acrylic adhesive composition. Novel optical sensors, fabricated using the aforementioned method, 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 preparation of a suitable indicator composition (16) and incorporation thereof in a silicone capsule (14) slidably arranged over the tip of a fiber optic (12), sealed with a suitable adhesive means (18). To amplify the signal obtained, the capsule (14) is preferably fabricated so as to contain reflective particules, and tapers to a narrow tip. Novel optical sensors are also provided, as are methods for using the sensors to evaluate CO2 concentration in a sample fluid.
Abstract:
A ratiometric method for using optical sensors (11) is provided to measure dissolved oxygen in a fluid sample. The sensor (11) is formulated so as to contain an oxygen permeable membrane (16) 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 (11) are provided as well.
Abstract:
A device (10) is provided for maintaining a volume of gas dissolved in a fluid (18) at a predetermined partial pressure. The device includes a first sealable, gas-tight pouch (12) containing the fluid and a second sealable, gas-tight pouch (14) encasing the first pouch and providing a space (16) 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 method is provided for calibrating sensors (14) used to analyze characteristics of physiologic fluids such as blood. The method involves the use of a sensor assembly (12) having an analyte responsive sensor (14) in communication with a physiologic line (28) and a conduit passageway (16). The method involves exposing the sensor (14) to a reference sample, thereby producing a sensor response. The method also allows performing quality control on sensors (14). Also provided is an apparatus (10) with which the claimed method may be practiced.
Abstract:
An optical sensor is provided for measuring the pH of a fluid sample. The sensor is formulated using a fluorescent polymer composition comprising a copolymer of a water-dispersable, polyether-containing urethane olefin precursor and a fluorescent monomer species, wherein the ratio of precursor and fluorescent monomer species is such that a predetermined apparent pKa is provided. The sensor is prepared by coating the distal end of an optical waveguide with the fluorescent polymer composition, and curing the copolymer contained in the composition, e.g., by exposure to radiation of a suitable wavelength.
Abstract:
An optical sensor (11) is provided for measuring dissolved gases such as O2 or CO2 in a fluid sample. The sensor (11) is formulated so as to contain a gas permeable membrane (17) of a cured perfluorinated urethane polymer and, incorporated therein, a gas-sensitive indicator component (22). Methods for making and using the membrane (17) and sensor (11) are provided as well.