Abstract: An apparatus for the nondestructive measurements of materials. Eddy current sensing arrays are described which provide a capability for high resolution imaging of test materials and also a high probabilitity of detection for defects. These arrays incorporate layouts for the sensing elements which take advantage of microfabrication manufacturing capabilities for creating essentially identical sensor arrays, aligning sensing elements in proximity to the drive elements, and laying out conductive pathways that promote cancellation of undesired magnetic flux.

Abstract: A digital potentiometer device has a potentiometer, coupled to a reference voltage, that generates a voltage that can be varied. A programmable scaling function scales the reference voltage and the potentiometer's wiper voltage depending on stored user variables. An analog-to-digital converter converts the scaled potentiometer voltage to a digital value readable by a controller circuit. The controller circuit controls the scaling function and display of the potentiometer position with the user variables.

Abstract: Described is an inspection method for detecting defects in dielectic test materials using a penetrant material and a dielectric sensor. The penetrant material provides differing dielectric properties from test material and improves the dielectric contrast between defects substantially filled by the penetrant and the test material. The penetrant can be a liquid, such as water, or a powder, as long as it provides a substantially different complex permittivity than the test material.

Abstract: A sensor is provided for measuring the speed of a moving sports object, particularly an object being shot or launched, for example, from a gun, bow or other implement, such as a bullet or paint ball being shot from a gun or an arrow being shot from a bow. The sensor is operable over a short range and is preferably mounted in close proximity to the path of the moving object. The sensor of the preferred embodiment utilizes CW Doppler radar in the form of a microwave radio frequency transmitter and receiver that has a single-transistor integrated antenna/oscillator. A simple, low cost unit having a low radiation and low energy consumption transmitter, receiver and signal processor, is provided. In use, the unit is situated so as to place a transmit/receive antenna close to or in the line of motion of the object. Such an antenna, so positioned, may be separated from the unit and connected through a transmission line.

Abstract: There is a need for a technique to compensate for, or eliminate, motion-induced artifacts in patient-attached critical care monitoring instruments. Also, a need exists to extend the accurate operational range of patient-attached pulse oximeters in environments when the patient's blood oxygen saturation is well below the normal physiologic range, or where there is low blood flow. Accordingly, 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. These approaches include measuring a pulsatile characteristic of the patient at a position close to, or at the pulse-oximetry measurement site, or using pulsatile characteristics that result from contraction of the patient's heart.

Abstract: Described are methods for pressurizing elastic support structures or balloons in sensor probes used for the inspection of components having areas of limited access. When inflated, the balloons press flexible sensors against the surface of the material under test. When deflated, the balloons permit easier insertion of the probes into the component and reduce the mechanical stresses on the sensors, thereby extending the sensor lifetime. By sequentially partially inserting the sensor into a limited access area from either side of the limited access area and scanning in opposite directions, the entire surface of the test material can be inspected.

Abstract: A sensor having a conductive protective sheath, an internal sensor element, and a conductive end cap. The conductive end cap is connected to the distal end of the conductive protective sheath and is in contact with the internal sensor element. The conductive protective sheath has a plurality of apertures symmetrically arranged to prevent fluid flow in a straight direction of a sample fluid through the conductive protective sheath. A sensor having a conductive protective sheath, an internal sensor element, and a conductive end cap. The conductive end cap is connected to the distal end of the conductive protective sheath. The conductive end cap one or more contact areas from the group including a side contact area, an upper contact area, and an internal indentation contact area. The internal sensor is in contact with at least one of the contact areas of the conductive end cap.

Abstract: The present invention relates to the use asymmetric monolayer forming species and electroconduit forming species to detect target analytes.

Abstract: The invention relates to the use of signal processing methods in order to acheive higher signal to noise ratios, to increase the detection limits of target analytes. These techniques include the monitoring of the output signal at higher harmonic frequencies.

Abstract: A sensor that characterizes welds in materials. The sensor includes a meandering drive winding with at least three extended portions and at least one sensing element placed between an adjacent pair of extended portions. A time varying electric current is passed through the extended portions to form a magnetic field. The sensor is placed in proximity to the test material and translated over the weld region. An electrical property of the weld region is measured for each sensing element location. The weld quality is determined using a feature of the electrical property measurement and location.

Abstract: A sensor signal conditioner for temperature compensating, linearizing, and amplifying sensor signal output in electronic instrumentation circuits includes a programmable gain instrument amplifier having an input connected to a sensor; and a comparator for comparing an output voltage of the amplifier to a desired output voltage value. A micro-controller controls the instrument amplifier gain and offset. A mode switch converts an I/O pin to input the desired output voltage value in programming mode and connects the I/O pin to the amplifier output in user mode. A memory stores a programming protocol in the sensor signal conditioner so that in programming mode, the protocol stores programmed values and linearly fits the programmed values to set trim values for temperature compensating, linearizing, and amplifying the instrument amplifier output. The I/O pins and mode switches of several sensor signal conditioners can be controlled simultaneously to mass produce transducers using the sensor signal conditioner.

Abstract: Inductive sensors measure the near surface properties of conducting magnetic materials. The sensors generally include parallel winding segments to induce a spatially periodic magnetic field in a material under test. The sensors may provide a directionally dependent measure with measurements made in varying orientations of the sensor with respect to the material property variation directions. The sensors may be thin, conformable sensors that can be mounted on a test material and, for example, monitor crack initiation under the sensor. A second sensor may be left in air to provide a reference measurement, or the temperature of the material under test can be varied to verify the response of the individual sensing elements. Sensors can be mounted to materials under test in order to not modify the environment that is causing the stress being monitored.

Abstract: Described are methods for monitoring of stresses and other material properties. These methods use measurements of effective electrical properties, such as magnetic permeability and electrical conductivity, to infer the state of the test material, such as the stress, temperature, or overload condition. The sensors, which can be single element sensors or sensor arrays, can be used to periodically inspect selected locations, mounted to the test material, or scanned over the test material to generate two-dimensional images of the material properties. Magnetic field or eddy current based inductive and giant magnetoresistive sensors may be used on magnetizable and/or conducting materials, while capacitive sensors can be used for dielectric materials. Methods are also described for the use of state-sensitive layers to determine the state of materials of interest. These methods allow the weight of articles, such as aircraft, to be determined.

Abstract: An apparatus and method for detecting at least one component gas in a sample includes a radiation source for providing radiation along an optical path in a pre-selected spectral band having at least one absorption line of the component gas to be detected and an optical detector for detecting radiation at the optical path. A sample chamber is positioned in the optical path between the source and the optical detector to contain a quantity of a sample gas. At least one gas cell enclosing an amount of the gas to be detected is fixedly positioned in the optical path in series with the gas chamber. A mathematical relationship is determined between the detected radiation and the concentration of a sample gas filling the sample chamber.

Abstract: A sensor for measuring the dielectric constant of a fluid uses time of flight measurements. The sensor has a conduit for the fluid, preferably a transmission line. The dielectric constant of the fluid affects tranmission of electrical energy along the transmission line. An electrical generator, having as output an electrical transient, is operably connected to one end of the transmission line for transmitting the electrical transient along the conduit, where propagation of the electrical conduit is affected by the fluid. A receiver is connected to the other end of the conduit for detecting electrical transients that have passed along the conduit from the electrical generator.

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: There is a need for a technique to compensate for, or eliminate, motion-induced artifacts in patient-attached critical care monitoring instruments. Also, a need exists to extend the accurate operational range of patient-attached pulse oximeters in environments when the patient's blood oxygen saturation is well below the normal physiologic range, or where there is low blood flow. Accordingly, 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. These approaches include measuring a pulsatile characteristic of the patient at a position close to, or at the pulse-oximetry measurement site, or using pulsatile characteristics that result from contraction of the patient's heart.

Abstract: Methods and apparatus are described for the inspection of materials and the detection and characterization of hidden objects, features, or flaws. Sensors and sensor arrays are used to image form two-dimensional images suitable for characterizing the hidden features. Magnetic field or eddy current based inductive and giant magnetoresistive sensors may be used on magnetizable and conducting materials, while capacitive sensors can be used for dielectric materials. Enhanced drive windings and electrode structures permit nulling or cancellation of local fields in the vicinity of the sense elements to increase sensor sensitivity. The addition of calibration windings, which are not energized during measurements, allows absolute impedance and material property measurements with nulled sensors. Sensors, sensor arrays, and support fixtures are described which permit relative motion between the drive and sense elements. This facilitates the volumetric reconstruction of hidden features and objects.

Abstract: The invention relates to a cartridge for packaging an analyte-containing fluid calibrant. The cartridge is formed from a container having an opening sealed by a sealing member. A septum divides the container into a calibrant compartment and an outer compartment. A probe is provided comprising an analyte-detecting portion and a connecting portion that allows for operative connection to a device for quantitating or determining the concentration of the analyte. The probe may extend sealingly through the septum such that the analyte-detecting portion is located in the calibrant compartment and the connecting portion is located in the outer compartment. The construction of the cartridge provides ease and reduces the likelihood of error in calibrating the probe. The invention also relates to a method of manufacturing the cartridge and a method for calibrating a device for analyte concentration determination and quantitation using the inventive cartridge.

Abstract: The invention relates to compositions and methods useful in the detection of nucleic acids using a variety of amplification techniques, including both signal amplification and target amplification. Detection proceeds through the use of an electron transfer moiety (ETM) that is associated with the nucleic acid, either directly or indirectly, to allow electronic detection of the ETM using an electrode.