2764 results about "Time constant" patented technology

A cooled electrosurgical system includes an electrosurgical device having at least one electrode for applying electrical energy to tissue. In one embodiment, the electrode includes an internal cavity in which a cooling medium such as water is contained. The internal cavity is closed at both ends of the device such that the cooling medium is contained within the electrode at the surgical site such that the cooling medium does not contact the tissue being treated. The electrosurgical device has an electrode and a heat pipe to conduct heat from the electrodes where substantially all heat conducted from the electrode through the heat pipe is dissipated along the length of the heat pipe. The heat pipe can have a thermal time constant less than 60 seconds and preferably less than 30 seconds.

A charge control circuit for controlling a micro-electromechanical system (MEMS) device having variable capacitor formed by first conductive plate and a second conductive plate separated by a variable gap distance. The charge control circuit comprises a switch circuit configured to receive a reference voltage having a selected voltage level and configured to respond to an enable signal having a duration at least as long as an electrical time constant constant of the MEMS device, but shorter than a mechanical time constant of the MEMS device, to apply the selected voltage level across the first and second plates for the duration to thereby cause a stored charge having a desired magnitude to accumulate on the variable capacitor, wherein the variable gap distance is a function of the magnitude of the stored charge.

A control circuit controlling output current at the primary side of a power converter is provided. A waveform detector generates a current-waveform signal. A discharge-time detector detects a discharge-time of a secondary side switching current. An oscillator generates an oscillation signal for determining the switching frequency of the switching signal. An integrator generates an integrated signal by integrating an average current signal with the discharge-time. The average current signal is generated in response to the current-waveform signal. The time constant of the integrator is correlated with the switching period of the switching signal, therefore the integrated signal is proportional to the output current. An error amplifier amplifies the integrated signal and provides a loop gain for output current control. A comparator controls the pulse width of the switching signal in reference to the output of the error amplifier. Therefore, the output current of the power converter can be regulated.

The present invention comprises one or more microprocessors programmed to execute methods for improving the performance of an analyte monitoring device including prediction of glucose levels in a subject by utilizing a predicted slower-time constant (1 / k2). In another aspect of the invention, pre-exponential terms (1 / c2) can be used to provide a correction for signal decay (e.g., a Gain Factor). In other aspects, the present invention relates to one or more microprocessors comprising programming to control execution of (i) methods for conditional screening of data points to reduce skipped measurements, (ii) methods for qualifying interpolated / extrapolated analyte measurement values, (iii) various integration methods to obtain maximum integrals of analyte-related signals, as well as analyte monitoring devices comprising such microprocessors. Further, the present invention relates to algorithms for improved optimization of parameters for use in prediction models that require optimization of adjustable parameters.

A method, electrical tissue stimulation system, and programmer for providing therapy to a patient are provided. Electrodes are placed adjacent tissue (e.g., spinal cord tissue) of the patient, electrical stimulation energy is delivered from the electrodes to the tissue in accordance with a defined waveform, and a pulse shape of the defined waveform is modified, thereby changing the characteristics of the electrical stimulation energy delivered from the electrode(s) to the tissue. The pulse shape may be modified by selecting one of a plurality of different pulse shape types or by adjusting a time constant of the pulse shape.

A generic model structure captures basic characteristics in BIS-based patients' responses to anesthesia and surgical stimulation, the model being used in combination with the insight of an anesthesiologist. The model structure represents the patient response with a time delay, a time constant for response speed, and a nonlinear function for drug sensitivity. Clinical data confirms the model structure and is used to establish parameters and function forms for individual patients. A feedback and predictive control strategy for anesthesia drug infusion is then introduced on the basis of the patient model. Feedback control alone cannot avoid large fluctuations in BIS values when significant surgical stimulation is imposed, as a result of time delays in a patient's response to drug infusion. Predictive control attenuates fluctuations of BIS levels from surgical stimulation.

NAND architecture Flash memory strings, memory arrays, and memory devices are described that utilize depletion mode floating gate memory cells. Depletion mode floating gate memory cells allow for increased cell current through lower channel rdS resistance and decreased “narrow width” effect, allowing for increased scaling of NAND memory cell strings. In addition, the required voltages for reading and programming operations are reduced, allowing the use of more efficient, lower voltage charge pumps and a reduction circuit element feature sizes and layouts. Cell inhibit of unselected cells is also increased, reducing the likelihood of cell disturb in the memory array. Operation speed is improved by increasing read current of the selected NAND string and by increasing the ability to overcome the RC time constants of circuit lines and capacitances through lowered voltage swings and increased current supplies.

Voltage regulators often have coupled output inductors because coupled output inductors provide improvements in cost and efficiency. Coupled inductors are often used in multi-phase voltage regulators. Feedback control of voltage regulators often requires accurate and responsive sensing of output current. Provided is a technique for accurately sensing the magnitude of output current in coupled inductors. An RC circuit (comprising a resistor and capacitor in series) is connected in parallel with the coupled inductor. The inductor has a leakage inductance Lk and a DC (ohmic) resistance of DCR. The resistor and capacitor are selected such that an RC time constant is equal to an L / R time constant of Lk / DCR. With the matching time constants, a sum of voltages on the capacitors is accurately proportional to a sum of currents flowing in the output inductors. Also provided is a technique for sensing current when an uncoupled center tap inductor is present.

A method and system for calibrating a time constant within an integrated circuit. A voltage storage element is charged, and the time required to achieve a reference voltage on the storage element is measured. The measured time is compared to a desired time. It necessary, an adjustable impedance is modified to change the charging time, and the cycle may be repeated until the charging time matches the desired time. In this novel manner, an actual RC time constant, as rendered in a particular integrated circuit, is measured and potentially adjusted to match a desired time constant. Advantageously, configuration information of the adjustable impedance may be communicated to other circuitry within the integrated circuit to enable such circuitry to implement the same RC time constant in analog signal processing. Consequently, embodiments of the present invention overcome incidences of wide tolerance in passive components implemented in integrated circuits. Beneficially, no external test equipment is required.

Methods and apparatuses for providing virtual temperature sensor to control temperatures in a data processing system. In one aspect, a data processing system includes a virtual temperature sensor to provide system temperature for different system configurations, and a controller coupled to the sensor to control operations of the data processing system according to the virtual temperature. The virtual temperature sensor typically derives the temperature of a particular configuration of the data processing system using mathematical models or one or more operating parameters of the data processing system. In one example, the mathematical models include a characterization table which provides the measured temperature data from various system configurations. These measurements are performed with temperature sensors positioned in ideal locations for different configuration, and are preprocessed to provide the virtual temperature computation. The characterization table also includes thermal characteristics, such as thermal time constant and thermal resistance, of the critical components at multiple thermal control states.

A background noise estimate based upon a modified Doblinger noise estimate is used for modulating the output of a pseudo-random phase spectrum generator to produce the comfort noise. The circuit for estimating noise includes a smoothing filter having a slower time constant for updating the noise estimate during noise than during speech. Comfort noise is smoothly inserted by basing the amount of comfort noise on the amount of noise suppression. A discrete inverse Fourier transform converts the comfort noise back to the time domain and overlapping windows eliminate artifacts that may have been produced during processing.

It is an object of the invention to improve the utility of an electromagnetic absorber system which is disposed in a suspension system of a vehicle and which generates a damping force by a generation force of a motor. The electromagnetic absorber system 18 is equipped with high-speed-motion responding means, thereby obviating an insufficiency of the damping force and a deterioration of the controllability in a high-speed stroke motion. More specifically, a hydraulic absorber 64 is provided in combination with the electromagnetic absorber system such that the hydraulic absorber 64 operates in the high-speed motion in which an electromotive force of the motor 68 exceeds a power source voltage Further, two motors having mutually different T-N characteristics are provided, and the two motors are selectively operated depending upon a stroke speed. Further, a variable resistor is interposed between the motor and the power source, and a resistance value of the variable resistor is increased in the high-speed motion to realize a decrease in a time constant of the motor, etc. Moreover, to cope with a large extent of unevenness of a road surface, an active stroke motion is performed by a drive force of the motor, thereby preventing the high-speed motion from being performed.

A direct current (DC)-DC converter that includes a first switching converter and a multi-stage filter is disclosed. The multi-stage filter includes at least a first inductance (L) capacitance (C) filter and a second LC filter coupled in series between the first switching converter and a DC-DC converter output. The first LC filter has a first LC time constant and the second LC filter has a second LC time constant, which is less than the first LC time constant. The first switching converter and the multi-stage filter form a feedback loop, which is used to regulate the first switching power supply output signal based on the setpoint. The first LC filter includes a first capacitive element having a first self-resonant frequency, which is about equal to a first notch frequency of the multi-stage filter.

A real-time multicast scheduler method and apparatus is presented, to facilitate multicasting of real-time constant bit rate data in wireless ad-hoc networks. Constant bit rate traffic cannot tolerate delay jitter. However, a small amount of packet losses may be tolerable. In order to ensure the provisioning of a desired level of quality of service, bandwidth is reserved on the multicast structure. A goal of the real-time multicast scheduler is to avoid packet collisions and to facilitate color re-use, where "color" is defined as a channel selected as a combination of time-division multiple access, frequency-division multiple access, and code-division multiple access schemes. The real-time multicast scheduler provides a self-healing network which corrects for disconnections caused by node movement and nodes moving out of range of each other, while accounting for colors already assigned for data transmission in order to prevent packet collisions.

An apparatus and method thereof for measuring an output current from a primary side of a power converter are provided. A peak detector is designed to sample a peak value of a converted voltage of a primary-side switching current. A zero-current detector detects a discharge-time of a secondary-side switching current through an auxiliary winding of a transformer. An oscillator generates a switching signal for switching the power converter. An integrator generates an integrated signal by integrating the converted voltage of the primary-side switching peak current with the discharge-time. The time constant of the integrator is correlated with the switching period of the switching signal. The integrated signal is thus proportional to the output current of the power converter.

A diesel powered vehicle is provided with an SCR system which uses an external reducing reagent to convert NOx emissions in a manner which accounts for the effects of NOx transient emissions on the reducing catalyst. Actual NOx emissions produced by the engine are filtered using a variable NOx time constant in turn correlated to the reductant / NOx storage capacity of the reducing catalyst at its current temperature to account for changes in the SCR system attributed to NOx transient emissions. Catalyst temperature is filtered using a variable catalyst time constant corresponding to current space velocity of the exhaust gas to account for changes in the catalyst temperature attributed to NOx transient emissions. The reductant is metered on the basis of the filtered, corrected NOx concentration applied at a NSR ratio based, in turn, on the filtered, corrected reducing catalyst temperature.

A method of synchronizing clocks in the stations of ad hoc and infrastructure networks includes providing a time stamp field in a header; reading the header by all stations in a network; extracting the time stamp information from the header by each station in the network as time information; sending extracted time information to a station clock; and adjusting the station clock as a function of the extracted time information. A system for synchronizing clocks in the stations of ad hoc and infrastructure networks includes a DLL having a comparator for receiving the time stamp information and a low-pass filter having a long time-constant for adjusting the station clock in a gradual manner; a time stamp field in a header; and time information extracted from the time stamp information of the header by each station in the network.

Method and apparatus for the treatment of cardiac failure, Cheyne Stokes breathing or central sleep apnea are disclosed. A subject is provided with ventilatory support, for example positive pressure ventilatory support using a blower and mask. Respiratory airflow is determined. From the respiratory airflow are derived a measure of instantaneous ventilation (for example half the absolute value of the respiratory airflow) and a measure of longterm average ventilation (for example the instantaneous ventilation low pass filtered with a 100 second time constant). A target ventilation is taken as 95% of the longterm average ventilation. The instantaneous ventilation is fed as the input signal to a clipped integral controller, with the target ventilation as the reference signal. The output of the controller determines the degree of ventilatory support. Clipping is typically to between half and double the degree of support that would do all the respiratory work. A third measure of ventilation, for example instantaneous ventilation low pass filtered with a time constant of 5 seconds, is calculated. Ventilatory support is in phase with the subject's respiratory airflow to the fuzzy extent that this ventilation is above target, and at a preset rate conversely.

Method and apparatus for the treatment of cardiac failure, Cheyne Stokes breathing or central sleep apnea are disclosed. A subject is provided with ventilatory support, for example positive pressure ventilatory support using a blower and mask. Respiratory airflow is determined. From the respiratory airflow are derived a measure of instantaneous ventilation (for example half the absolute value of the respiratory airflow) and a measure of longterm average ventilation (for example the instantaneous ventilation low pass filtered with a 100 second time constant). A target ventilation is taken as 95% of the longterm average ventilation. The instantaneous ventilation is fed as the input signal to a clipped integral controller, with the target ventilation as the reference signal. The output of the controller determines the degree of ventilatory support. Clipping is typically to between half and double the degree of support that would do all the respirator work. A third measure of ventilation, for example instantaneous ventilation low pass filtered with a time constant of 5 seconds, is calculated. Ventilatory support is in phase with the subject's respiratory airflow to the fuzzy extent that this ventilation is above target, and at a preset rate conversely.

A bio-electrode for detecting heart signals and the like comprises a dry electode surface having an elevated resistivity to reduce the effect of polarization noise. The electrode is combined with a circuit having an external discharge resistor across which an output signal is obtained wherein the discharge resistor has a value which reduces the time constant of polarization noise to less than one second.

A method of determining state of charge of an energy delivery device includes sampling voltage values of the energy delivery device during relaxation of the device. The method further includes regressing an open circuit voltage value and the total overpotential being relaxed. The regression includes a predetermined time constant of relaxation associated with the energy delivery device. One embodiment uses the equation V(t)=OCV−α exp(−t / tau), where V(t) represents the sampled voltage values, t represents times at which each of the voltage values are sampled, OCV represents the open circuit voltage value of the energy delivery device, α represents the overpotential value, and tau represents the time constant of relaxation. The method uses a predetermined profile that relates open circuit voltage of the energy delivery device to state of charge of the device, to determine a particular state of charge corresponding to the regressed open circuit voltage value.

A liquid crystal display panel with reduced flicker comprises an active matrix substrate equipped with a plurality of thin film transistors. The active matrix substrate has an active area that is formed with a plurality of first signal lines and a plurality of second signal lines crossing each other. The active area includes a plurality of pixels arranged in a matrix. There are outer-lead bonding areas around the active area. There are a plurality of pad areas within the outer-lead bonding areas. A plurality of second wires arranged in a fan-out configuration extend from the pad areas and stretch toward the active area. The second wires are connected to their respective first signal lines by their serpentine or zigzag routes resulting in various wire lengths. A frame-like lead overlaps the second wires, and a capacitor exists between each of the second wires and the closed frame-like lead. The induced capacitor and the resistance of the corresponding second wire together result in a compensation effect so as to uniform the time constants of the plurality of first signal lines.

A speech separating apparatus includes: a PARCOR calculating unit (102) that extracts vocal tract information from an input speech signal; a filter smoothing unit (103) that smoothes, in a first time constant, the vocal tract information extracted by the PARCOR calculating unit (102); an inverse filtering unit (104) that calculates a filter coefficient of a filter having a frequency amplitude response characteristic inverse to the vocal tract information smoothed by the filter smoothing unit (103), so as to filter the input speech signal using the filter having the calculated filter coefficient; and a voicing source modeling unit (105) that cuts out, from the input speech signal filtered by the inverse filtering unit (104), a waveform included in a second time constant shorter than the first time constant, so as to calculate, for each waveform that is taken, voicing source information from the each waveform.

When an accelerator opening Acc is equal to or more than a threshold value A2 upon a shift from a N position to a D position, a target torque T* is set to gradually change in comparison with when the accelerator opening Acc is less than the threshold value A2 based on a torque demand Trq corresponding to the accelerator opening Acc and a time constant T or a gradual change restriction until a satisfaction of a release condition. An Engine 22, motors MG1 and MG2 are controlled so as to ensure a driving torque equivalent to the target torque T*.

A user interface (210) includes an RC circuit (213). The RC circuit (213) includes a variable capacitance. The variable capacitance is produced by a sensing member (310) in cooperation with a user's finger (311). When a user makes a selection with the user interface (210), the user places a finger (311) in close proximity and in a facing relationship to a section, or discrete surface (320, 322, 324), of the sensing member (310). The discrete surfaces (320, 322, 324) can correspond to keys of a keypad (138) or to directions of a directional button (1030), for example. The time constant of the RC circuit (213) varies according to which discrete surface (320, 322, 324) is determining the capacitance of the RC circuit (213). A controller (118) determines the user's selection based on the time constant of the RC circuit (213).

A process for measuring the absorption spectrum of a target analyte using a cavity ring down spectrometer, comprising the steps of: i) tuning the spectrometer laser so that the light transmitted from the laser into the spectrometer optical cavity is varied over a wavelength interval which encompasses both the absorption wavelength of a spectral feature of the target analyte and a plurality of the free spectral ranges of the optical cavity; ii) triggering a plurality of ringdown events; iii) for each ringdown event, recording the decay time constant and the trigger time at which the light into the cavity is shut off; iv) organizing the decay time constants, light wavelengths and trigger times as a function of trigger time; v) ordering said light wavelengths by increasing value and placing groups of wavelengths into individual bins; vi) computing the average wavelength of each bin group; vii) grouping the decay time constants and trigger times into bins that parallel said wavelength bins, with the decay time constants in each of said parallel bin being arranged by increasing trigger time; viii) computing the average decay time for each decay time bin and using this decay time average, together with the average wavelength from the parallel wavelength bin, to compute the optical loss for the target analyte at said average wavelength.

Systems and methods are disclosed that facilitate determining coil temperature in a proximity sensor, such as an extended range inductive proximity sensor. Voltage measurements can be taken before, and during, damped oscillatory decay of a voltage in a resonant circuit in the proximity sensor to determine a value, γ, associated with an inductive time constant for the resonant circuit. The gamma value comprises information related to both inductance and resistance in the sensor coil, and can be employed to determine coil temperature. Derivation of the gamma value, and thus of coil temperature, can utilize a current pulse of a duration of approximately one RC time constant of the resonant circuit, thus mitigating current consumption by the proximity sensor during temperature assessment.

An output buffer having a controlled output slew rate comprises a first predriver circuit having a first RC circuit and a first output node and a second predriver circuit having a second RC circuit and a second output node. A buffer input node is coupled to the first and second predriver circuits. The output buffer further includes an output circuit having first and second input nodes and a third output node, where the first and second input nodes are coupled, respectively, to the first and second output nodes. The time constants of the RC circuits control a signal slew rate at the third output node of the output circuit, and the value of R may be selected to provide a predetermined, controlled slew rate range at the third output node. A selection circuit aids in the selection of an appropriate value for R.

A response delay compensation element for compensating a response delay of an output gMAF of an airflow meter by a phase advance compensation is provided so that an output g of the response delay compensation element is input to the intake air system model. A transfer function of the phase advance compensation is <paragraph lvl="0"><in-line-formula>g=(1+T1.s) / (1+T2s).gMAF< / in-line-formula>where T1 and T2 are time constant of the phase advance compensation, which is set based on at least one of the output gMAF of the airflow meter, engine speed, an intake air pressure, and a throttle angle. The model time constant τIM of the intake air system model is calculated by variables including volumetric efficiency and the engine speed. The volumetric efficiency is calculated by two-dimensional map having the engine speed and the intake air pressure as parameters thereof.

An apparatus and method thereof for measuring an output current from a primary side of a power converter are provided. A peak detector is designed to sample a peak value of a converted voltage of a primary-side switching current. A zero-current detector detects a discharge-time of a secondary-side switching current through an auxiliary winding of a transformer. An oscillator generates a switching signal for switching the power converter. An integrator generates an integrated signal by integrating the converted voltage of the primary-side switching peak current with the discharge-time. The time constant of the integrator is correlated with the switching period of the switching signal. The integrated signal is thus proportional to the output current of the power converter.