Abstract: An exemplary embodiment of a method of detecting hydrocarbons in Systems and methods for sensing analytes in an aqueous solution, include pretreating a water sample to provide a test sample. A flow cell includes at least one sensor with a polymer coating having at least partial selectivity for at least one analyte. The flow cell receives a test sample and a reference sample. At least one output signal from the at least one sensor is processed with a microcontroller using a model of the sensor response and a bank of Kalman filters to estimate a concentration of at least one analyte in the aqueous solution.

Abstract: An exemplary embodiment of a method of detecting hydrocarbons in Systems and methods for sensing analytes in an aqueous solution, include pretreating a water sample to provide a test sample. A flow cell includes at least one sensor with a polymer coating having at least partial selectivity for at least one analyte. The flow cell receives a test sample and a reference sample. At least one output signal from the at least one sensor is processed with a microcontroller using a model of the sensor response and a bank of Kalman filters to estimate a concentration of at least one analyte in the aqueous solution.

Abstract: A process for a pre-concentration unit including: a sorbent material coated passage-way having an entrance for receiving a hydrocarbon-containing groundwater sample and for pre-concentrating the hydrocarbons in a hydrocarbon-containing groundwater sample by successive sorption/desorption cycles, and having an exit for discharging the pre-concentrated hydrocarbons; a heating unit for heating the sorbent material coated passage-way; and; an array of shear horizontal-surface acoustic wave sensors with coatings adapted for detecting and quantifying the pre-concentrated hydrocarbons, disposed at the exit of the sorbent material coated passage-way; and a housing for enclosing the pre-concentration unit and the array of shear horizontal-surface acoustic wave sensors, adapted for continuous use at a body of hydrocarbon-containing groundwater, and coupled to mathematical methods for generating concentrations of specific analytes from both transient and steady-state signals.

Abstract: A process for a pre-concentration unit including: a sorbent material coated passage-way having an entrance for receiving a hydrocarbon-containing groundwater sample and for pre-concentrating the hydrocarbons in a hydrocarbon-containing groundwater sample by successive sorption/desorption cycles, and having an exit for discharging the pre-concentrated hydrocarbons; a heating unit for heating the sorbent material coated passage-way; and; an array of shear horizontal-surface acoustic wave sensors with coatings adapted for detecting and quantifying the pre-concentrated hydrocarbons, disposed at the exit of the sorbent material coated passage-way; and a housing for enclosing the pre-concentration unit and the array of shear horizontal-surface acoustic wave sensors, adapted for continuous use at a body of hydrocarbon-containing groundwater, and coupled to mathematical methods for generating concentrations of specific analytes from both transient and steady-state signals.

Abstract: The present invention comprises a sensor for measuring an analyte in a medium comprising a piezoelectric resonator having a first side with an electroded region and a second opposing side having an electroded region that is different in size and/or shape of the first electrode. The piezoelectric resonator of the present invention is capable of measuring more than one parameter thereby providing a multi-information sensing device. The present invention also includes an apparatus and method for detecting and measuring an analyte in a medium which utilizes the piezoelectric resonator sensor of the present invention.

Abstract: An AT cut quartz crystal resonator has an unbalanced electrode geometry to induce a particularly strong electrical field in a surface of the resonator adjacent a medium. The electrical field will interact with ions and dipoles in the medium and may be used to accurately and repeatably measure the electrical characteristics of the medium. Specific examples are provided illustrating the use of a sensor designed in accord with the invention in sensing dilute electrolytes, and other applications are contemplated.

Abstract: A cochlear prosthesis composed of a transmitter part which is to be carried exterior to the user's body and a receiver part which is to be implanted in the user, the transmitter and receiver parts being coupled by a radio link provided by implanted receiver coils and external transmitter coils free of any percutaneous connections. In the transmitter part, sound signals are obtained in plurality of channels, and these channels are frequency multiplexed into a composite signal with the aid of a plurality of surface acoustic wave filters, each having a respective passband. In the implanted receiver, the received composite signal is frequency demultiplexed by means of a similar plurality of surface acoustic wave filters each having a respective passband. A further signal is transmitted from the transmitter part to the receiver part via the radio link in order to supply operating power for the circuits in the receiver part, where the further signal is rectified to produce d.c. operating voltages.