16166 results about "Harmonic" patented technology

A method and an apparatus measure blood oxygenation in a subject. A first signal source applies a first input signal during a first time interval. A second signal source applies a second input signal during a second time interval. A detector detects a first parametric signal responsive to the first input signal passing through a portion of the subject having blood therein. The detector also detects a second parametric signal responsive to the second input signal passing through the portion of the subject. The detector generates a detector output signal responsive to the first and second parametric signals. A signal processor receives the detector output signal and demodulates the detector output signal by applying a first demodulation signal to a signal responsive to the detector output signal to generate a first output signal responsive to the first parametric signal. The signal processor applies a second demodulation signal to the signal responsive to the detector output signal to generate a second output signal responsive to the second parametric signal. The first demodulation signal and the second demodulation signal both include at least a first component having a first frequency and a first amplitude and a second component having a second frequency and a second amplitude. The second frequency is a harmonic of the first frequency. The second amplitude is related to the first amplitude to minimize crosstalk from the first parametric signal to the second output signal and to minimize crosstalk from the second parametric signal to the first output signal.

A processor provides signal quality based limits to a signal strength operating region of a pulse oximeter. These limits are superimposed on the typical gain dependent signal strength limits. If a sensor signal appears physiologically generated, the pulse oximeter is allowed to operate with minimal signal strength, maximizing low perfusion performance. If a sensor signal is potentially due to a signal induced by a dislodged sensor, signal strength requirements are raised. Thus, signal quality limitations enhance probe off detection without significantly impacting low perfusion performance. One signal quality measure used is pulse rate density, which defines the percentage of time physiologically acceptable pulses are occurring. If the detected signal contains a significant percentage of unacceptable pulses, the minimum required signal strength is raised proportionately. Another signal quality measure used in conjunction with pulse rate density is energy ratio, computed as the percentage of total energy contained in the pulse rate fundamental and associated harmonics.

A system for transmitting power without wires or with no more than one connection, wherein communication is provided between an unlimited number of electronic devices, or to connect these devices to an unlimited number networks that are located externally to the system to thereby enable high speed voice and data communications over a single resonant connection At least one transmitter and one receiver are utilized, which may have the same or different configurations, such that an induced oscillating electπc current, which occurs at the resonant frequency of a transmitter, induces a standing wave The standing wave is tuned and “tapped” by a receiver having a coil or set of plates and receivers that are tuned to oscillate at the same frequency or one of its harmonics and, thus, absorb an electrical current and / or signals at the receiver

The present invention relates to using a trap-rich layer, such as a polycrystalline Silicon layer, over a semiconductor substrate to substantially immobilize a surface conduction layer at the surface of the semiconductor substrate at radio frequency (RF) frequencies. The trap-rich layer may have a high density of traps that trap carriers from the surface conduction layer. The average release time from the traps may be longer than the period of any present RF signals, thereby effectively immobilizing the surface conduction layer, which may substantially prevent capacitance and inductance changes due to the RF signals. Therefore, harmonic distortion of the RF signals may be significantly reduced or eliminated. The semiconductor substrate may be a Silicon substrate, a Gallium Arsenide substrate, or another substrate.

A telemetry method and apparatus using pressure sensing elements remotely located from associated pick-up, and processing units for the sensing and monitoring of pressure within an environment. This includes remote pressure sensing apparatus incorporating a magnetically-driven resonator being hermetically-sealed within an encapsulating shell or diaphragm and associated new method of sensing pressure. The resonant structure of the magnetically-driven resonator is suitable for measuring quantities convertible to changes in mechanical stress or mass. The resonant structure can be integrated into pressure sensors, adsorbed mass sensors, strain sensors, and the like. The apparatus and method provide information by utilizing, or listening for, the residence frequency of the oscillating resonator. The resonant structure listening frequencies of greatest interest are those at the mechanical structure's fundamental or harmonic resonant frequency. The apparatus is operable within a wide range of environments for remote one-time, random, periodic, or continuous / on-going monitoring of a particular fluid environment. Applications include biomedical applications such as measuring intraocular pressure, blood pressure, and intracranial pressure sensing.

A technique for enhancing audio signals generated from compressed digital audio files is described. The technique uses a Bass Maximizer module, a Harmonic Exciter module and a Quasi Stereo module. The Bass Exciter module enhances the intensity, depth and punch of the bass audio content by creating harmonic sequences from low frequency components contained in the original input signal. The Harmonic Exciter module adds to the treble audio content of the original input signal by generating harmonic series from the high frequency components contained in the input signal. The Quasi Stereo Module creates a stereo image of the enhanced input signal by adding and subtracting delayed and filtered versions of the enhanced input signal with itself to create left and right channeled stereo-like outputs. The technique provides a useful tool to regenerate from an audio signal more pleasant and joyful sounds.

Dual-band and multi-band radiating elements are described based on composite right / left-handed (CRLH) meta-material transmission line (TL). These elements can operate as resonators and / or antennas depending on feed-line configuration. The radiating elements are based on the fundamental backward wave supported by a composite right / left-handed (CRLH) meta-material transmission line (TL). Unit-cells of the transmission line comprise conductive patches coupled through vias to a ground plane. The physical size and operational frequencies of the radiating element is determined by the unit cell of the CRLH meta-material. This radiating element is configured for monopolar radiation at a first resonant frequency and patch-like radiation at a second resonant frequency. The first and second resonant frequencies are not constrained to a harmonic relationship.

An improved audio coding technique encodes audio having a low frequency transient signal, using a long block, but with a set of adapted masking thresholds. Upon identifying an audio window that contains a low frequency transient signal, masking thresholds for the long block may be calculated as usual. A set of masking thresholds calculated for the 8 short blocks corresponding to the long block are calculated. The masking thresholds for low frequency critical bands are adapted based on the thresholds calculated for the short blocks, and the resulting adapted masking thresholds are used to encode the long block of audio data. The result is encoded audio with rich harmonic content and negligible coder noise resulting from the low frequency transient signal.

A method and apparatus for use in improving the linearity characteristics of MOSFET devices using an accumulated charge sink (ACS) are disclosed. The method and apparatus are adapted to remove, reduce, or otherwise control accumulated charge in SOI MOSFETs, thereby yielding improvements in FET performance characteristics. In one exemplary embodiment, a circuit having at least one SOI MOSFET is configured to operate in an accumulated charge regime. An accumulated charge sink, operatively coupled to the body of the SOI MOSFET, eliminates, removes or otherwise controls accumulated charge when the FET is operated in the accumulated charge regime, thereby reducing the nonlinearity of the parasitic off-state source-to-drain capacitance of the SOI MOSFET. In RF switch circuits implemented with the improved SOI MOSFET devices, harmonic and intermodulation distortion is reduced by removing or otherwise controlling the accumulated charge when the SOI MOSFET operates in an accumulated charge regime.

The present invention is directed toward a pulse oximetry system for the determination of a physiological parameter capable of removing motion artifacts from physiological signals comprises a hardware subsystem and a software subsystem. The software subsystem is used in conjunction with the hardware subsystem to perform a method for removing a plurality of motion artifacts from the photo-plethysmographic data and for obtaining a measure of at least one physiological parameter from the data. The method comprises acquiring the raw photo-plethysmographic data, transforming the data into the frequency domain, analyzing the transformed data to locate a series of candidate cardiac spectral peaks (primary plus harmonics), reconstructing a photo-plethysmographic signal in the time domain with only the candidate cardiac spectral peaks (primary plus harmonics), computing the second order derivative of the reconstructed photo-plethysmographic signal, analyzing the candidate second order derivative photo-plethysmographic signal to determine the absence or presence of cardiac physiologic signal characteristics, and finally selecting the best physiologic candidate from the series of potential cardiac spectral peaks (primary plus harmonics) based upon a second derivative scoring system. This scoring system is preferentially based upon second derivative processing analysis, but can be equally applied using the first, third, fourth or other similar derivative processing analysis.

Medical diagnostic apparatus and methods are disclosed. Ultrasound radiation pressure selectively modulates a target area within a body. One or more pulses of radiation containing temporally correlated groups of photons are generated. The photons are characterized by two or more different wavelengths that are selected to have specific interaction with a target chromophore. The two or more different wavelengths are also selected to have substantially similar scattering cross-sections and anisotropy parameters in the target and its surroundings. The pulses of radiation are injected into the body proximate the target area being modulated by the radiation pressure field. Photon groups at each of the different wavelengths that are backscattered from the target area are detected in temporal coincidence. Time-gated background-free amplification of the return signal is used to exclude photons which could not by virtue of their arrival time have interacted with the radiation-pressure-modulated target. Photon groups are selected with a modulation component at the modulation frequency of the radiation pressure modulation field, or at a harmonic of the modulation frequency. From the arrival rate of the detected temporally correlated photon pairs or multiplets, chemical information about the target area, such as an oxygenation or pH level can be inferred. Cardiac output may be computed from measurements of venous and / or arterial oxygenation using this technique.

The present invention discloses a primary-side feedback switching power supply that uses a sample-and-hold circuit to obtain a corner voltage of a harmonic wave voltage while the primary-side auxiliary winding is operating at a discontinuous mode as a feedback control, and provides both voltage regulation and current limit functions. A stable voltage output is provided within the nominal input voltage and nominal output load, such that when the output reaches a current limit, the output voltage drops but the output current is controlled to remain unchanged, so as to provide an over-current protection.

The determination of blood glucose in an individual is carried out by projecting illuminating light into an eye of the individual to illuminate the retina with the light having wavelengths that are absorbed by rhodopsin and with the intensity of the light varying in a prescribed temporal manner. The light reflected from the retina is detected to provide a signal corresponding to the intensity of the detected light, and the detected light signal is analyzed to determine the changes in form from that of the illuminating light. For a biased sinusoidal illumination, these changes can be expressed in terms of harmonic content of the detected light. The changes in form of the detected light are related to the ability of rhodopsin to absorb light and regenerate, which in turn is related to the concentration of blood glucose, allowing a determination of the relative concentration of blood glucose. Other photoreactive analytes can similarly be determined by projecting time varying illuminating light into the eye, detecting the light reflected from the retina, and analyzing the detected light signal to determine changes in form of the signal due to changes in absorptivity of a photoreactive analyte.

A voltage controlled oscillator having low phase noise and including: a variable resonator including a varactor and a control voltage terminal; and an open-end stub connected in parallel to the variable resonator, the open-end stub having a length shorter than or equal to an odd multiple of one quarter of a wavelength of a harmonic signal plus one sixteenth of the wavelength of the harmonic signal, and longer than or equal to an odd multiple of one quarter of the wavelength of the harmonic signal minus one sixteenth of the wavelength of the harmonic signal. In this structure, a high Q value is realized for a fundamental wave frequency. Fluctuation in a control voltage due to a harmonic signal is controlled.

The invention discloses an array of pixels to be arranged in electronic color imaging devices, where the risk of aliasing is reduced by arranging the pixels in the array according to irregular patterns. The array is provided with a first, a second and a third set of pixels representing a first, a second and a third color respectively. The pixels in the first set of pixels and / or the pixels in the second set of pixels are arranged in at least a first spatial frequency, and the pixels in the third set of pixels are arranged in at least a second spatial frequency. In addition, one of said first or second set of pixels may be arranged in at least a third spatial frequency. None of said first, second and third spatial frequencies are harmonics of each other. The array may be implemented in one or several different matrixes of pixels.

Apparatus for transmitting a digital signal within, for example, an integrated circuit includes a signal transmission line with a directional coupler at one or both ends. The directional coupler blocks the direct-current component of the digital signal while transmitting the alternating-current component, including enough higher harmonics to transmit a well-defined pulse waveform. A suitable directional coupler consists of two adjacent line pairs in materials with different dielectric constants. The apparatus may also include a driver of the inverter type, a receiver of the differential amplifier type, a terminating resistor, and a power-ground transmission line pair for supplying power to the driver. An all-metallic transmission-line structure is preferably maintained from the output interconnections in the driver to the input interconnections in the receiver.

A novel MMIC on-chip power-combined frequency multiplier device and a method of fabricating the same, comprising two or more multiplying structures integrated on a single chip, wherein each of the integrated multiplying structures are electrically identical and each of the multiplying structures include one input antenna (E-probe) for receiving an input signal in the millimeter-wave, submillimeter-wave or terahertz frequency range inputted on the chip, a stripline based input matching network electrically connecting the input antennas to two or more Schottky diodes in a balanced configuration, two or more Schottky diodes that are used as nonlinear semiconductor devices to generate harmonics out of the input signal and produce the multiplied output signal, stripline based output matching networks for transmitting the output signal from the Schottky diodes to an output antenna, and an output antenna (E-probe) for transmitting the output signal off the chip into the output waveguide transmission line.

A set (50) of one or more laser pulses (52) is employed to remove passivation layer (44) over a conductive link (22). The link (22) can subsequently be removed by a different process such as chemical etching. The duration of the set (50) is preferably shorter than 1,000 ns; and the pulse width of each laser pulse (52) within the set (50) is preferably within a range of about 0.05 ps to 30 ns. The set (50) can be treated as a single “pulse” by conventional laser positioning systems (62) to perform on-the-fly material removal without stopping whenever the laser system (60) fires a set (50) of laser pulses (52) at each target area (51). Conventional wavelengths in the IR range or their harmonics in the green or UV range can be employed.

A self-powered current monitor for monitoring current in electric power systems. Various data relating to input currents may be displayed, such as current magnitude, current demand, and harmonics levels. Operating power is derived from one or more of the input currents. The power supply configuration may include a burden-reducing means to reduce the burden on input current sources during sampling of the input currents. The self-powered current monitor (1) includes a power supply section (3), input resistors (R1 and R3), an analog-to-digital converter circuit (5), a microprocessor circuit (6), a memory circuit (9), and a display circuit (7). Optional features include a burden-reducing circuit (2), input circuit protective elements (D1, D2, D3, D4, R2, and R4), an amplifier circuit (4), a user interface circuit (10), and an interface circuit (8) for communication to other equipment.

Disclosed is a transmission system for transmitting digital information via a power supply network. In one embodiment, there is a transmission device which comprises a generator for generating a simulated digital wave-form carrying the digital information to be transmitted, and a high-voltage injector to inject the generated simulated digital wave-form carrying the digital information into the power supply network. A receiving device is also disclosed, which comprises an analog detector for detecting predetermined harmonic frequencies of a signal frequency, and a logic device to output a logic signal corresponding to the output of the analog detector as said digital information.

A novel and useful apparatus for and method of distributed coexistence for mitigating interference in a single chip radio and / or a multi-radio (i.e. multi-transceiver) communications device. The invention enables coexistence ‘friendly’ radio IPs having frequency agility in that they are capable of shifting their clock frequencies thereby avoiding frequency bands of potential victim radios. Frequency agility on the aggressor radio side (rather than by mitigating the effect of interference on the victim radio side) prevents harmonics from the aggressor's clock scheme from falling in the operating frequency band of the victim radio, and in turn causing degradation to its performance. Each aggressor radio, based on information received from other radios, configures the root clock frequency of its RX and / or TX chain clock generation circuits.

An optical fiber scanner is used for multiphoton excitation imaging, optical coherence tomography, or for confocal imaging in which transverse scans are carried out at a plurality of successively different depths within tissue. The optical fiber scanner is implemented as a scanning endoscope using a cantilevered optical fiber that is driven into resonance or near resonance by an actuator. The actuator is energized with drive signals that cause the optical fiber to scan in a desired pattern at successively different depths as the depth of the focal point is changed. Various techniques can be employed for depth focus tracking at a rate that is much slower than the transverse scanning carried out by the vibrating optical fiber. The optical fiber scanner can be used for confocal imaging, multiphoton fluorescence imaging, nonlinear harmonic generation imaging, or in an OCT system that includes a phase or frequency modulator and delay line.

A passive harmonic switch mixer is shown that is immune to self mixing of the local oscillator greatly reducing leakage noise, pulling noise, and flicker noise when used in a direct conversion receiver or direct conversion transmitter circuit. The passive harmonic switch mixermixes an input signal received on an input port with an in-phase oscillator signal and a quadrature-phase oscillator signal and outputs an output signal on an output port. Because the quadrature-phase oscillator signal is the in-phase oscillator signal phase shifted by 90 °, the passive harmonic switch mixer operates with a local oscillator running at half the frequency of the carrier frequency of an RF signal. Additionally, because the passive harmonic switch mixer has no active components, the DC current passing through each switch device is reduced and the associated flicker noise of the mixer is also greatly reduced.

A handheld ultrasound instrument is disclosed having enhanced diagnostic modes including pulse / continuous wave Doppler, time-motion analysis, spectral analysis and tissue harmonic imaging. An external electrocardiograph (ECG) recording unit is also disclosed. The ECG unit is adaptable to be used with the handheld ultrasound instrument to provide for ECG monitoring while performing an ultrasound scan in B-mode, Doppler, color Doppler, M-mode, and CW / PW mode. The enhanced handheld ultrasound instrument further includes a security mechanism allowing any combination of the diagnostic modes to be enabled by the manufacturer, and later to enable or disable any one or group of the diagnostic modes. The invention also discloses a method for a manufacturer to maintain a database of handheld ultrasound instrument capabilities after the instruments enter the stream of commerce.

A varying magnetic field excites slight vibrations in an object and a radar sensor detects the vibrations at a harmonic of the excitation frequency. The synergy of the magnetic excitation and radar detection provides increased detection range compared to conventional magnetic metal detectors. The radar rejects background clutter by responding only to reflecting objects that are vibrating at a harmonic excitation field, thereby significantly improving detection reliability. As an exemplary arrangement, an ultra-wideband micropower impulse radar (MIR) is capable of being employed to provide superior materials penetration while providing range information. The magneto-radar may be applied to pre-screening magnetic resonance imaging (MRI) patients, landmine detection and finding hidden treasures.

A power converting device includes a single-phase multiplex converter used as an active filter and a control device. The single-phase multiplex converter includes multiple single-phase inverters connected in series at AC output sides. Each of the single-phase inverters converts DC power fed from a DC power supply into AC power. The control device includes hysteresis comparators and controls output voltage of the single-phase multiplex converter by gradational output voltage control, based on the sum of selectively combined output voltages of the multiple single-phase inverters. The control device controls the single-phase multiplex converter so that an output current follows a harmonic compensation reference current, canceling harmonics leaking from a load to which the power converting device is connected.

High-frequency couplers and coupling techniques are described utilizing artificial composite right / left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight / loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.

PCT No. PCT / SG97 / 00013 Sec. 371 Date Oct. 8, 1998 Sec. 102(e) Date Oct. 8, 1998 PCT Filed Apr. 7, 1997 PCT Pub. No. WO97 / 37591 PCT Pub. Date Oct. 16, 1997A method and apparatus for determination of heart rate, heart stroke volume, heart stroke volume, and cardiac output from thoracic bioimpedance signals and electrocardiograms. A unique bioimpedance electrode arrangement is employed, and the bioimpedance signals are corrected for gain-phase-frequency distortion through the use of sinusoidal test signals through the measuring or detection electrodes to identify distortions and correct for same during actual measurements. Time-derivative bioimpedance signals are employed, the power spectrum calculated, and a novel autoconvolution procedure used to emphasize the heart rate harmonic. Breath waves and other signals not indicative of the patient's cardiocycles are removed. Left ventricular ejection time is derived from the bioimpedance signals, and an improved version of Kubicek's equation is employed to derive heart stroke volume and thus cardiac output.

In one embodiment, a method of receiving a decoded audio signal that has a transmitted pitch lag is disclosed. The method includes estimating pitch correlations of possible short pitch lags that are smaller than a minimum pitch limitation and have an approximated multiple relationship with the transmitted pitch lag, checking if one of the pitch correlations of the possible short pitch lags is large enough compared to a pitch correlation estimated with the transmitted pitch lag, and selecting a short pitch lag as a corrected pitch lag if a corresponding pitch correlation is large enough. The postprocessing is performed using the corrected pitch lag. In another embodiment, when the existence of irregular harmonics or wrong pitch lag is detected, a coded-excited linear prediction (CELP) postfilter is made more aggressive.