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: 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: An efficient method for the microfabrication of electronic devices which have been adapted for the analyses of biologically significant analyte species is described. The techniques of the present invention allow for close control over the dimensional features of the various components and layers established on a suitable substrate. Such control extends to those parts of the devices which incorporate the biological components which enable these devices to function as biological sensors. The materials and methods disclosed herein thus provide an effective means for the mass production of uniform wholly microfabricated biosensors. Various embodiments of the devices themselves are described herein which are especially suited for real time analyses of biological samples in a clinical setting. In particular, the present invention describes assays which can be performed using certain ligand/ligand receptor-based biosensor embodiments.

Abstract: A microfabricated sensing device is disclosed, including methods for using the same for the measurement of the concentration of a gas in a sample. Unique sensor configurations are described which substantially eliminate electrode cross-contamination during operation of the microfabricated sensing devices.

Abstract: An efficient method for the microfabrication of electronic devices which have been adapted for the analyses of biologically significant analyte species is described. The techniques of the present invention allow for close control over the dimensional features of the various components and layers established on a suitable substrate. Such control extends to those parts of the devices which incorporate the biological components which enable these devices to function as biological sensors. The materials and methods disclosed herein thus provide an effective means for the mass production of uniform wholly microfabricated biosensors. Various embodiments of the devices themselves are described herein which are especially suited for real time analyses of biological samples in a clinical setting. In particular, the present invention describes assays which can be performed using certain ligand/ligand receptor-based biosensor embodiments.

Abstract: The present invention relates to an apparatus for conducting a variety of assays that are responsive to a change in the viscosity of a sample fluid and relates to methods of conducting such assays. In particular, the present invention is related to the use of a cartridge for conducting one or more coagulation assays or, conversely, fibrinolysis assays. The disclosed device enjoys simplicity and is adaptable to the point-of-care clinical diagnostic area, including use in accident sites, emergency rooms, surgery or intensive care units.

Abstract: A method of forming a permselective layer on preselected areas of a substantially planar sensing device is disclosed. The claimed method includes establishing and confining a liquid film, derived from a silane compound mixed in a suitable solvent, within a predetermined area of the sensing device. The process relates to photolithographic imaging and developing methods coupled to a film-curing step that provides a patterned permselective layer having the desired semipermeable characteristics.

Abstract: An efficient method for the microfabrication of electronic devices which have been adapted for the analyses of biologically significant analyte species is described. The techniques of the present invention allow for close control over the dimensional features of the various components and layers established on a suitable substrate. Such control extends to those parts of the devices which incorporate the biological components which enable these devices to function as biological sensors. The materials and methods disclosed herein thus provide an effective means for the mass production of uniform wholly microfabricated biosensors. Various embodiments of the devices themselves are described herein which are especially suited for real time analyses of biological samples in a clinical setting. In particular, the present invention describes assays which can be performed using certain ligand/ligand receptor-based biosensor embodiments.

Abstract: A method of determining the concentration of a preselected analyte species present in a sample fluid is disclosed, which method comprises: (a) providing an external computational means, a reference electrode and at least one substantially dry-stored sensor capable of exhibiting a response to changes in the concentration of a preselected analyte species before the sensor attains full equilibrated wet-up; (b) establishing electrical contact between the sensor, reference electrode and external computational means; (c) contacting the sensor and reference electrode with a calibrant fluid; (d) performing a first signal measurement in a first time window in the presence of the calibrant fluid; (e) displacing the calibrant fluid after performing the first signal measurement; (f) contacting the sensor and reference electrode with a sample fluid; (g) performing a second signal measurement in a second time window in the presence of the sample fluid; and (h) relating the first and second signal measurements to determine

Abstract: A system comprising a disposable device and hand held reader can perform a variety of electrochemical measurements on blood or other fluids. In operation, a fluid sample is drawn into the disposable device through an orifice by capillary action. The orifice is sealed off and the disposable device is inserted into the reader. The reader which controls the test sequence and flow of fluid causes a calibrant pouch located inside the device to be pierced, releasing the calibrant fluid to flow across the sensor arrays to perform calibration. Next an air bladder located in the device is depressed, forcing the sample across the sensors where measurements are performed and read by the reader which performs the calibrations. Once the measurements are made, the device can be withdrawn from the reader and discarded.

Abstract: A plurality of uniform microfabricated sensing devices are produced by establishing a plurality of base sensors on a substrate wafer, forming over at least a portion of each base sensor a permselective layer, superimposing a photoformable proteinaceous photoresist layer over a substantial portion of the permselective layer, and forming a topmost layer of an immobilized ligand receptor. The ligand receptor and corresponding ligand may be immunoreactive species.

Abstract: An electrode for measuring the activity of ionic species. The electrode comprises a material which is chemically sensitive to at least one ionic species. The material comprises an insulating component and a conductive component of lower resistivity than the insulating component. The insulating component has a density of proton binding sites sufficiently large to be sensitive to the ionic species. The conductive component comprises particles, the size of which are sufficiently small to modify the bulk conductive properties such that the susceptibility of the particles to redox interference in the operation of the electrode is decreased, while maintaining sufficient conductivity to operate in Faradaic electrode configurations. Illustratively, the insulating component is tantalum oxide, zirconium oxide or aluminum oxide and the conductive component is iridium, platinum, ruthenium, palladium, rhodium or osmium oxide.

Abstract: A fluidics head to facilitate the automatic testing of chemical and ionic sensing electronic circuit devices is provided. The fluidics head comprises a fluid confining cell having an open orifice capable of containing a known test fluid while the orifice is in leakproof engagement with sensing electronic circuit devices, an inlet and outlet opening capable of filling and discharging test fluids, and electrical probes capable of contacting the sensing electronic circuit devices so as to test the electrical response of the devices with the test fluids.

Abstract: An improved connector for connection to and identification and testing of electric components such as integrated circuits is described which features a number of spring biased contact elements normally in contacting relation with a shorting bar. When a particular component is placed in a specified physical relation to the connector, a combination of exposed electrical contacts and nonconductive elements on the component to be tested displace specified ones of the contact members away from the shorting bars, providing a connection pattern which can be detected. At the same time, test signals can be applied to the electric component to be tested. The circuit may be identified and its specific parameters identified and characterized in a single operation according to the invention. Advantageously, the shorting bar is grounded so that any static charge on the component to be tested is grounded before the contact elements are displaced from the shorting bar.

Abstract: An improved reference electrode is disclosed for use in potentiometric measurements of the amount of ions in an aqueous solution. The reference electrode illustratively comprises a metal member on a substrate, and a layer of a salt reversible to the ion X overlying the metal member. The reference electrode is overlaid by a quantity of an electrolyte, which may be a polymer gel having a salt including the ion X dispersed therein. This structure is overlaid by a membrane permeable to water but not to the ion X that extends beyond the portion of the electrolyte overlying the electrode, but leaves a portion of the electrolyte exposed. This assembly may be shipped dry. In use, when the electrode is disposed in an aqueous solution containing an ionic species to be measured, water permeates the membrane and "wets up" the electrolyte relatively quickly.

Abstract: A method and apparatus for automatically testing chemical and ionic sensing electronic circuits is provided. A fluid used in testing is placed in a hollow pipette with at least one open end. The open end of the pipette is applied directly against a sensing layer on the sensing electronic circuit forming a leakproof seal. Alternatively, a flow-through type fluid container is used and is advantageously applied with gas measurements. Test electronics are provided to compile and analyze the performance of various sensing layers. Aligning means automatically select a sensing electronic circuit and position the circuit such that the holding device can be urged against the sensing layer automatically.

Abstract: An ambient sensing device is described especially suited to the sensing of a variety of ambient parameters. Photolithographic techniques are used to pattern a multiplicity of sensitive layers on a single monolithic substrate taking into account the wide range of plastic, gelatinous and ceramic materials to be patterned and the problems of their cross-contamination when in contact.