11948results 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.

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.

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.

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.