35 results about "Immittance" patented technology

An apparatus and method manage impedance values in a radio in a wireless network. The apparatus includes a tunable matching network (TMN) positioned on a path between a transceiver and an antenna. The TMN includes a plurality of immittance elements. A voltage standing wave ratio (VSWR) detector is configured to detect a ratio of a signal passing the VSWR detector and a signal reflected from the TMN. A control circuit is configured to identify an operating setting for the radio, set a number of the immittance elements based on the operating setting, monitor the ratio detected by the VSWR detector, and modify a setting of at least one of the immittance elements based on the ratio detected.

This invention relates to a high efficiency single-phase and the three-phase incorporation generating system. This incorporation generating system is composed by the high frequency inverter, immittance convertor, high-frequency transformer, high frequency rectifier, power frequency inverter, lowpass filter, voltage zero crossing detector, high frequency drive circuit and power frequency drive circuit. This system counter turn the direct voltage which are gained by light battery array, fuel cell, windpower generation and other methods to high-frequency voltage and input immittance convertor. The high-frequency current output by immittance convertor is merged into single-phase or three-phase electric network olationand by the high-frequency transformer, ranking transformed by electric current, commutated by the high frequency rectifier, counter turned by the power frequency inverter and filtered by lowpass filter. By improving the system topology, reducing the power transistor number, this invention not only reduces the cost, realize installment miniaturization, but also reduces the power loss in the energy transfer process.

A testing device detects and quantifies cell deterioration of an electrochemical cell or battery. The device contains measuring circuitry adapted to apply time-varying electrical excitation to said cell or battery, to sense time-varying electrical response to said excitation, and to utilize said excitation and response to determine components of complex immittance (i.e., either impedance or admittance) at n+m discrete frequencies, where n is an integer equal to or greater than two and m is an integer equal to or greater than one. Computation circuitry utilizes measured complex immittance components at the n discrete frequencies to evaluate the elements of a 2n-element equivalent circuit model. It then calculates the complex immittance of this model at the m discrete frequencies and mathematically compares components of the calculated immittances with components of the measured immittances at the m discrete frequencies. The results of this comparison are related to the degree of cell deterioration. A pass/fail determination can thus be made based solely upon cell deterioration—without even knowing the battery's manufacturer, group size, or its electrical ratings.

This invention relates to a sensor assembly and a method for measuring characteristics of a surface, preferably skin, comprising a first pair of current supply electrodes coupled to a current source, providing an electrical current to the skin, at least one pickup electrodes at chosen positions relative to the current supply electrodes, at least a first of said pickup electrodes being coupled to an instrument for measuring the voltage between said first pickup electrode and at least one of the pickup or current supply electrodes.

A differential circuit topology that produces a tunable floating negative inductance, negative capacitance, negative resistance/conductance, or a combination of the three. These circuits are commonly referred to as “non-Foster circuits.” The disclosed embodiments of the circuits comprises two differential pairs of transistors that are cross-coupled, a load immittance, multiple current sources, two Common-Mode FeedBack (CMFB) networks, at least one tunable (variable) resistance, and two terminals across which the desired immittance is present. The disclosed embodiments of the circuits may be configured as either a Negative Impedance Inverter (NII) or a Negative Impedance Converter (NIC) and as either Open-Circuit-Stable (OCS) and Short-Circuit-Stable (SCS).

Described herein are devices, systems, and methods for determining the composition of liquids, including the identity of one or more drugs in the liquid, the concentration of the drug, and the type of diluent using immittance spectroscopy. These devices, systems and methods are particularly useful for describing the identity and, in some variations, concentration of one or more components of a medical liquid such as intravenous fluid. In particular, described herein are devices, systems and methods that may operate in low ionic strength diluents. Also described are methods of recognizing complex immittance spectrograph patterns to determine the composition of a liquid by pattern recognition.

The invention provides a digital automatic acoustic-control otoacoustic immittance detection system and a digital signal compensation method thereof. The system sequentially comprises a probe tone D/A (digital to analog) conversion circuit, a drive circuit, a speaker, a human ear, a pick-up and an A/D (analog to digital) conversion circuit which are connected in series, wherein the input end of the probe tone D/A conversion circuit and the output end of the A/D conversion circuit are connected with an FPGA (field programmable gate array) chip correspondingly and respectively; the output end of the FPGA chip is connected with the probe tone D/A conversion circuit through an acoustic-control D/A conversion circuit; and the FPGA chip is also connected with a CPU (central processing unit) which is connected with a display/peripheral interface unit. The method comprises the following steps of: calculating an echo signal difference deltaV= Vi-Vref between a test ear and a standard ear, wherein Vi is a test ear echo signal, and Vref is standard ear reference voltage; and calculating a volume control voltage value delta= KdeltaV+ Vref according to the echo signal difference between the test ear and the standard ear, wherein K is between 0 and 1. According to the system and the method, digital real-time otoacoustic immittance measurement and a constant-voltage acoustic control functioncan be realized, and acoustic measurement strength in a detection and measurement process is maintained to be constant.

An apparatus and method for encoding/decoding a speech signal which determines a variable bit rate based on reserved bits obtained from a target bit rate, is provided. The variable bit rate is determined based on a source feature of the speech signal and the reserved bits is obtained based on the target bit rate. The apparatus for encoding the speech signal may include a linear predictive (LP) analysis unit/quantization unit to determine an immittance spectral frequencies (ISF) index, a closed loop pitch search unit, a fixed codebook search unit, a gain vector quantization (VQ) unit to determine a gain vector quantization (VQ) index, and a bit rate control unit to control at least two indexes of the ISF index, the pitch index, the code index, and the gain VQ index to be encoded to be variable bit rates based on a source feature of a speech signal and the reserved bits.

A hemolysis detection method and system includes measuring a conductance of a blood sample in a sample test module at a plurality of multiple-frequency AC inputs provided by a sine-wave generator module, calculating an immittance value for each of the plurality of multiple-frequency AC inputs received from a multichannel A/D converter module using a computer processing module, and subjecting each immittance value calculated to a function that maps immittance values to either lysed blood levels or hematocrit levels residing in the processing module and applying further processing residing in a memory module to produce respective percent-lysed value or hematocrit value of the blood sample.

Electrochemical detection method and related aspects Herein is disclosed an electrochemical test method comprising (i) comparing how a plurality of immittance functions and/or components thereof vary with a change in a parameter of interest for a first system, and then selecting an immittance function or component thereof for use in an electrochemical test; (ii) carryingout an electrochemical test step for a second system to determine at least one value for the immittance function or component thereof selected in step (i), and then, by using a quantitative relationship between the selected immittance function and the parameter of interest, determining a value in the parameter of interest. A computer program and apparatus are also disclosed herein.

An immittance conversion circuit includes a first terminal and a second terminal, and includes: a conversion target circuit configured to amplify or attenuate a signal with desired frequency and gain characteristics, and output the resultant signal; a difference signal detection circuit configured to supply the input terminal of the conversion target circuit with a signal of a difference between signals generated at the first and second terminals; an immittance conversion drive circuit configured to perform differential output processing to generate a voltage of a difference between a correction voltage and the signal outputted from the conversion target circuit, and output feedback signals to an immittance conversion generation circuit; and the immittance conversion generation circuit having an immittance conversion generation action to generate, at each of the first and second terminals, a signal of currents or voltages of the corresponding inputted feedback signal and the signal inputted to the first or second terminal. A signal of a difference between the signals generated at the first and second terminals is inputted to the immittance conversion drive circuit as the correction voltage.