11923results about "Material resistance" patented technology

A method of measuring an analyte in a biological fluid comprises applying an excitation signal having a DC component and an AC component. The AC and DC responses are measured; a corrected DC response is determined using the AC response; and a concentration of the analyte is determined based upon the corrected DC response. Other methods and devices are disclosed.

The invention relates to a method for detecting a double-stranded region in a nucleic acid by (1) providing two separate, adjacent pools of a medium and a interface between the two pools, the interface having a channel so dimensioned as to allow sequential monomer-by-monomer passage of a single-stranded nucleic acid, but not of a double-stranded nucleic acid, from one pool to the other pool; (2) placing a nucleic acid polymer in one of the two pools; and (3) taking measurements as each of the nucleotide monomers of the single-stranded nucleic acid polymer passes through the channel so as to differentiate between nucleotide monomers that are hybridized to another nucleotide monomer before entering the channel and nucleotide monomers that are not hybridized to another nucleotide monomer before entering the channel.

Improved microfluidic devices, systems, and methods allow selective transportation of fluids within microfluidic channels of a microfluidic network by applying, controlling, and varying pressures at a plurality of reservoirs. Modeling the microfluidic network as a series of nodes connected together by channel segments and determining the flow resistance characteristics of the channel segments may allow calculation of fluid flows through the channel segments resulting from a given pressure configuration at the reservoirs. To effect a desired flow within a particular channel or series of channels, reservoir pressures may be identified using the network model. Viscometers or other flow sensors may measure flow characteristics within the channels, and the measured flow characteristics can be used to calculate pressures to generate a desired flow. Multi-reservoir pressure modulator and pressure controller systems can optionally be used in conjunction with electrokinetic or other fluid transport mechanisms.

An apparatus for detection and quantitation of an electrochemically-detectable analyte, such as glucose, in blood or interstitial fluid includes a meter unit, a lancet and an electrochemical sensor. Of these components, the meter is preferably reusable, while the lancet and the electrochemical sensor are preferably incorporated in assemblies intended for single-use. The meter unit has a housing, within which a lancet is engaged with a mechanism for moving then lancet; a connector disposed within the housing for engaging an electrochemical sensor specific for the analyte and transmitting a signal indicative of the amount of analyte, and a display operatively-associated with a connector for displaying the amount of the analyte to user. The electrochemical sensor is adapted for detection of a particular analyte. In addition, the electrochemical sensor has an absorptive member for uptake of a sample of blood or interstitial fluid. In one version, the lancet moves from a initial position to a piercing position in which skin of the user is pierced and optionally back to a retracted position. The electrochemical sensor is disposed such that the absorptive member takes up a sample from the pierced skin of the user when it is pierced by the lancet without movement of the apparatus. In an alternative version, the lancet is a hollow cannula through which blood or interstitial fluid is transported from the puncture site to an absorbent portion of the electrochemical sensor. In either version, the apparatus provides single-step operation in which sample acquisition and analysis occur as a result of the single action of pressing, the apparatus against the users skin.

A method and apparatus that use complex impedance measurements of tissue in human or animal bodies for the detection and characterization of medical pathologies is disclosed. An analysis of the complex impedance measurements is performed by a trained evaluation system that uses a nonlinear continuum model to analyze the resistive, capacitive, and inductive measurements collected from a plurality of sensing electrodes. The analysis of the impedance measurements results in the construction of a multidimensional space that defines the tissue characteristics, which the trained evaluation system uses to detect and characterize pathologies. The method and apparatus are sufficiently general to be applied to various types of human and animal tissues for the analysis of various types of medical pathologies.

The invention is embodied in a plasma flow device or reactor having a housing that contains conductive electrodes with openings to allow gas to flow through or around them, where one or more of the electrodes are powered by an RF source and one or more are grounded, and a substrate or work piece is placed in the gas flow downstream of the electrodes, such that said substrate or work piece is substantially uniformly contacted across a large surface area with the reactive gases emanating therefrom. The invention is also embodied in a plasma flow device or reactor having a housing that contains conductive electrodes with openings to allow gas to flow through or around them, where one or more of the electrodes are powered by an RF source and one or more are grounded, and one of the grounded electrodes contains a means of mixing in other chemical precursors to combine with the plasma stream, and a substrate or work piece placed in the gas flow downstream of the electrodes, such that said substrate or work piece is contacted by the reactive gases emanating therefrom. In one embodiment, the plasma flow device removes organic materials from a substrate or work piece, and is a stripping or cleaning device. In another embodiment, the plasma flow device kills biological microorganisms on a substrate or work piece, and is a sterilization device. In another embodiment, the plasma flow device activates the surface of a substrate or work piece, and is a surface activation device. In another embodiment, the plasma flow device etches materials from a substrate or work piece, and is a plasma etcher. In another embodiment, the plasma flow device deposits thin films onto a substrate or work piece, and is a plasma-enhanced chemical vapor deposition device or reactor.

An air monitoring system is disclosed having an air monitoring unit with at least one sensor for measuring data of an air quality parameter and a computer for storing the air quality parameter data received from the sensor. The air monitoring unit may use an installed or a portable system, or a combination of both, for measuring the air quality parameters of interest. A remote data center may be provided, and the data may be uploaded to the data center from the unit by a communications media such as the Internet. Information or instructions may also be downloaded from the data center to the unit via the communications media for controlling or modifying the function of the unit. An expert system may be provided with the air monitoring system for controlling the unit. The information or instructions downloaded to the unit may be generated by the expert system.

Sensor platforms and methods of making them are described. A platform having a non-horizontally oriented sensor element comprising one or more nanostructures such as nanotubes is described. Under certain embodiments, a sensor element has or is made to have an affinity for an analyte. Under certain embodiments, such a sensor element comprises one or more pristine nanotubes. Under certain embodiments, the sensor element comprises derivatized or functionalized nanotubes. Under certain embodiments, a sensor is made by providing a support structure; providing one or more nanotubes on the structure to provide material for a sensor element; and providing circuitry to electrically sense the sensor element's electrical characterization. Under certain embodiments, the sensor element comprises pre-derivatized or pre-functionalized nanotubes. Under other embodiments, sensor material is derivatized or functionalized after provision on the structure or after patterning. Under certain embodiments, a large-scale array of sensor platforms includes a plurality of sensor elements.

A device, system and method for diagnosing and treating gastric disorders is provided. A functional device resides within the patient's stomach and is secured to the stomach wall by an attachment device. The functional device may be a sensor for sensing various parameters of the stomach or stomach environment, or may be a therapeutic delivery device. The functional device in one embodiment provides a device, system and method for gastric electrical stimulation where stimulating electrodes are secured to the wall of the stomach by the attachment device or otherwise. A preferred device includes: at least one stimulating electrode in electrical contact with the stomach wall; an electronics unit containing the electronic circuitry of the device; and an attachment mechanism for attaching the device to the stomach wall. The functional devices may be programmed to respond to sensed information or signals. An endoscopic delivery system delivers the functional device through the esophagus and into the stomach where it is attached the stomach wall. The endoscopic instruments attach or remove the attachment devices and functional devices from the stomach and may be used to assist in determining the optimal attachment location.

The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components. For example, semiconductor materials can be doped to form n-type and p-type semiconductor regions for making a variety of devices such as field effect transistors, bipolar transistors, complementary inverters, tunnel diodes, light emitting diodes, sensors, and the like.

A microfluidic analytical system for monitoring an analyte (for example, glucose) in a liquid sample (e.g., ISF) includes an analysis module with at least one micro-channel for receiving and transporting a liquid sample, at least one analyte sensor for measuring an analyte in the liquid sample and at least one position electrode. The analyte sensor(s) and position electrode(s) are in operative communication with the micro-channel. The microfluidic system also includes a meter configured for measuring an electrical characteristic (such as impedance or resistance) of the position electrode(s). Moreover, the measured electrical characteristic is dependent on the position of the liquid sample in the micro-channel that is in operative communication with the position electrode for which an electrical characteristic is measured.

A sensing system for use in monitoring the structural health of a structure such as a polymeric matrix composite structure is provided. The system includes a sensor formed from a conductive ink containing carbon nanofibers and a polymeric resin, and a data acquisition system for acquiring and evaluating data from the sensor. The conductive ink may be applied directly to the structure to be monitored in the form of a grid pattern. Damage to the structure may be detected by measuring changes in resistance values detected from the sensor.

A remote-control self-navigation water quality sampling and analyzing device belongs to the field of water quality monitoring, sampling and analyzing system integration in environmental protection, and in particular relates to self-navigation running and water quality sampling and analyzing detection technology. The device comprises a carrier [1], a wireless communication module [2], a sampling and analyzing module [3], an environmental sensor module [4], a remote monitoring platform [5], a self-navigation system [6], a control module [7], and the like. The device has the characteristics of remote monitoring, automatic acquisition, sample dividing storage, automatic record of related information and the like in the overall process of sampling water quality, and simultaneously has the advantage of quick and accurate acquisition of time and spacial information; and the water quality analyzing module of the device can acquire partial water quality analyzing results in the first time, so the device can greatly improve the accuracy, authenticity, timeliness, intellectuality and monitoring efficiency of water quality field sampling, can reduce sampling risk and cost, and has significance on water area water quality monitoring.

Absorbent articles comprising one or more sensors capable of detecting the presence of a body waste in the absorbent article are described. In particular, the absorbent articles comprise at least one chemiresistor capable of detecting the presence of volatile organic compounds associated with a body waste. When a body waste is detected, an indicator means signals a caregiver and / or a user of the absorbent article that an insult has occurred

A direct resistance measurement probe for measuring corrosion levels and material loss. The probe includes a hollow body having a resistive element at one end that is exposed to the environment. The probe can have an internal or external power source that is electrically connected to the resistive element. A meter measures the electrical resistance of the resistive element providing data from which corrosion rates may be ascertained. A temperature sensing device measures the temperature of the resistive element. A pressure sensing device measures the pressure of the environment that the resistive element is subjected to. The probe does not use a comparative or ratiometric reference element.

An electric conductivity water probe consisting of a test chamber having a wall, a fluids input / output port, and a water input port, the wall having a first and at least a second wall section, the first and at least second wall sections being electrically isolated from each other by an electrical insulator; and a valve connected operatively to the fluids input / output port, the valve being adapted for alternately and permitting and resisting flows of fluids through the fluids port.

An analyte test sensor for use in measuring the concentration of a particular analyte in a test sample includes a non-conductive substrate, a reference electrode deposited on the substrate, a working electrode deposited on the substrate and a compensation electrode deposited on the substrate. The compensation electrode is provided with a resistive ladder and is designed to correct for test result inaccuracies which are the result of variances in the manufacturing of the test sensor. Specifically, in one embodiment, the compensation electrode corrects for test result inaccuracies in an analog manner by shunting a portion of the working current away from working electrode. In another embodiment, the compensation electrode corrects for test result inaccuracies in a digital manner by providing a calibration code which is proportional its resistance value. A batch of analyte test sensors are preferably manufactured in the following manner. An initial batch of the test sensors is constructed. Then, a limited sampling of the sensors is tested for accuracy using a control sample. Based on the test results, the resistance value of the compensation electrode for each remaining sensor in the batch is adjusted accordingly.