11605 results about "Signal-to-noise ratio" patented technology

A blood glucose monitoring system is disclosed which provides for inducing an active pulse in the blood volume of a patient. The induction of an active pulse results in a cyclic, and periodic change in the flow of blood through a fleshy medium under test. By actively inducing a change of the blood volume, modulation of the volume of blood can be obtained to provide a greater signal to noise ratio. This allows for the detection of constituents in blood at concentration levels below those previously detectable in a non-invasive system. Radiation which passes through the fleshy medium is detected by a detector which generates a signal indicative of the intensity of the detected radiation. Signal processing is performed on the electrical signal to isolate those optical characteristics of the electrical signal due to the optical characteristics of the blood.

A blood constituent monitoring method for inducing an active pulse in the blood volume of a patient. The induction of an active pulse results in a cyclic, and periodic change in the flow of blood through a fleshy medium under test. By actively inducing a change of the blood volume, modulation of the volume of blood can be obtained to provide a greater signal to noise ratio. This allows for the detection of constituents in blood at concentration levels below those previously detectable in a non-invasive system. Radiation which passes through the fleshy medium is detected by a detector which generates a signal indicative of the intensity of the detected radiation. Signal processing is performed on the electrical signal to isolate those optical characteristics of the electrical signal due to the optical characteristics of the blood.

An electrosurgical system is disclosed comprising a generator configured to electrosurgical coagulation waveforms. The generator includes a closed loop control system for controlling the electrosurgical coagulation waveforms. The closed loop control system includes a sensor configured to sense a tissue property and / or an energy property and to transmit the tissue property and / or the energy property as one or more sensor signals having an amplitude. The control system also includes a gain controller configured to process the at least one sensor signal to reduce the amplitude of the sensor signals and to obtain a signal to noise ratio of the at sensor signals within a predetermine range. A microprocessor coupled to the generator and is configured to adjust the electrosurgical coagulation waveforms as a function of the sensor signals.

The invention provides a design process that is used in the determination of the pattern of detector and illumination optical fibers at the sampling area of a subject. Information about the system, specifically a monochromator (e.g. to determine the optimal number of fibers at an output slit) and the bundle termination at a detector optics stack (e.g. to determine the optimal number of fibers at the bundle termination), is of critical importance to this design. It is those numbers that determine the ratio and number of illumination to detection fibers, significantly limiting and constraining the solution space. Additional information about the estimated signal and noise in the skin is necessary to maximize the signal-to-noise ratio in the wavelength range of interest. Constraining the fibers to a hexagonal perimeter and prescribing a hex-packed pattern, such that alternating columns contain illumination and detection fibers, yields optimal results. In the preferred embodiment of the invention, two detectors share the totality of the detection fibers at the sampling interface. A third group of detection fibers is used for classification purposes.

The method and apparatus for information conveyance and distribution to bidirectionally focus or guide a wide spectrum of electromagnetic waves propagated over a possible variety of propagation media, including free space or wireless, surface wave, and cable or wired transmission lines. The apparatus communicates with information devices immediately adjacent to these media wherein the devices, which are not themselves part of the apparatus, may have electromagnetic access to one another. The apparatus maintains adequate signal to noise ratio and low distortion for a possible variety of different signal modulation and encoding types which it can support while permitting transparent, simultaneous communications among a variety of devices. Spread spectrum techniques may be used within the apparatus to mitigate propagation medium distortions and impairments as well as to control access and provide a means for securing information within the corridor and for obtaining revenue. Adapters may be employed to provide either full or half duplex access to the information devices which utilize it.

An Ultra-Tightly Coupled GPS-inertial navigation system for use in a moving agile platform includes a range residual extractor that uses best curve fitting of a third order polynomial for estimating range residual. The curve-fitted residual is used to update an error Kalman filter. The error Kalman filter includes correction for navigation solution, and IMU and GPS parameters. The navigation solution together with GPS parameter corrections are used in a Tracking Predictor to generate high-sampling-rate carrier and code replicas. The curve-fitting error covariance indicates signal to noise ratio for the tracked GPS signal and may be used for early indication of interference or jamming.

A near IR spectrometer-based analyzer attaches continuously or semi-continuously to a human subject and collects spectral measurements for determining a biological parameter in the sampled tissue, such as glucose concentration. The analyzer includes an optical system optimized to target the cutaneous layer of the sampled tissue so that interference from the adipose layer is minimized. The optical system includes at least one optical probe. Spacing between optical paths and detection fibers of each probe and between probes is optimized to minimize sampling of the adipose subcutaneous layer and to maximize collection of light backscattered from the cutaneous layer. Penetration depth is optimized by limiting range of distances between paths and detection fibers. Minimizing sampling of the adipose layer greatly reduces interference contributed by the fat band in the sample spectrum, increasing signal-to-noise ratio. Providing multiple probes also minimizes interference in the sample spectrum due to placement errors.

The invention comprises transformation of a section of a data block independently of the transformation of separate or overlapping data blocks to determine a property related to the original matrix, where each of the separate or overlapping data blocks are derived from an original data matrix. The transformation enhances parameters of a first data block over a given region of an axis of the data matrix, such as signal-to-noise, without affecting analysis of a second data block derived from the data matrix. This allows for enhancement of analysis of an analyte property, such as concentration, represented within the original data matrix. A separate decomposition and factor selection for each selected data matrix is performed with subsequent score matrix concatenization. The combined score matrix is used to generate a model that is subsequently used to estimate a property, such as concentration represented in the original data matrix.

In vivo or in vitro monitoring of chemical and biochemical species (e.g., pH, or glucose levels) in the interstitial fluid of patients or in a sample of a fluid to be analyzed is provided by a probe (10, 70, 210, 270). For in vivo monitoring, the probe is readily inserted by a minimally invasive method. Optical or electrochemical sensing methods are employed to detect a physical or chemical change, such as pH, color, electrical potential, electric current, or the like, which is indicative of the concentration of the species or chemical property to be detected. Visual observation by the patient may be sufficient to monitor certain biochemicals (e.g., glucose) with this approach. A CAP membrane allows high enzyme loadings, and thus enables use of microminiature probes, and / or diagnosis of low levels of the analyte(s), with sufficient signal-to-noise ratio and low background current.

There are provided methods and apparatus for stereoscopic video coding using scalable video coding. A scalable video encoder includes an encoder (100) for encoding at least two views corresponding to multi-view video content by, encoding a particular view of the at least two views as a base layer, and encoding each of at least one other view of the at least two views as an enhancement layer using a prediction from a lower layer corresponding to at least one of the particular view and the at least one other view. The at least two views are encoded based on a selection from among at least two of temporal, spatial, and signal to noise ratio scalability techniques.

System comprised of a portable medical device and method for registering at least one of electrocardiographic (ECG), magnetocardiographic (MCG), physical activity, body position, respiration, temperature, blood pressure, vasomotor activity, blood flow, neural activity, and other physiological, and health data, extracting and representing the most significant parameters from time series (trends) of said data. The system achieves the necessary sensitivity (signal-to-noise ratio) in order to miniaturize the device by collecting data of at least one fiducial point in a cardiac complex over a period of at least one, and preferably, several seconds, and extracting the underlying typical patterns from these data. Due to the miniaturization (pocket-size), the system can be implemented in a shape of a pen (or another miniature shape) that can be worn in a pocket.

An apparatus and method for non-invasive measurement of glucose in human tissue by quantitative infrared spectroscopy to clinically relevant levels of precision and accuracy. The system includes six subsystems optimized to contend with the complexities of the tissue spectrum, high signal-to-noise ratio and photometric accuracy requirements, tissue sampling errors, calibration maintenance problems, and calibration transfer problems. The six subsystems include an illumination subsystem, a tissue sampling subsystem, a calibration maintenance subsystem, an FTIR spectrometer subsystem, a data acquisition subsystem, and a computing subsystem.

Embodiments of the invention relate to cellular wireless networks and are particularly suited to networks including different types of base stations. So-called femtocell base stations are typically deployed within a subscriber's premises and operate at low transmit power, providing a very limited area of wireless coverage. A femtocell is typically deployed within the area of wireless coverage of a conventional macrocell type of base station, and if handover from a macrocell is performed on the basis of the best signal to noise plus interference ratio, a connection is likely to be transferred to another macrocell rather than to a femtocell. However, in view of the low density of user equipments capable of transceiving with a femtocell, the femtocell could potentially provide a greater data rate to the user equipment terminal than is possible with a macrocell. A cellular wireless network according to an embodiment of the invention employs a method of handover algorithm that has dependence on both a measure of signal quality such as signal to noise plus interference ratio and on a measure of loading of the base station. The handover algorithm is thereby able to weight selection of a base station on the basis of data rate, and intelligently engineer handover to a femtocell.

The invention relates to pulsed oximeters used to measure blood oxygenation. The current trend towards mobile oximeters has brought the problem of how to minimize power consumption without compromising on the performance of the device. To tackle this problem, the present invention provides a method for controlling optical power in a pulse oximeter. The signal-to-noise ratio of the received baseband signal is monitored, and the duty cycle of the driving pulses is controlled in dependence on the monitored signal-to-noise ratio, preferably so that the optical power is minimized within the confines of a predetermined lower threshold set for the signal-to-noise ratio. In this way the optical power is made dependent on the perfusion level of the subject, whereby the power can be controlled to a level which does not exceed that needed for the subject.

A method and system for optimizing performance in a data-over-cable system. The method includes determining parameters for data transmission on an upstream channel of the data-over-cable system, and negotiating use of the parameters. A measurement is made of a signal-to-noise ratio (“SNR”) on the upstream channel. Associated with the SNR and a target packet-error-ratio (“PER”) are parameters that provide optimal data throughput. The parameters, such as symbol rate, type of modulation, or amount of error correction, are used to construct a message that is sent to the cable modems. The message instructs the cable modems to reconfigure themselves to transmit according to the parameters. The reconfiguration helps ensure optimal performance.

A system for providing an accurate prediction of a signal-to-interference noise ratio is described. The system includes a first circuit for receiving a signal transmitted across a channel via an external transmitter. A second circuit generates a sequence of estimates of signal-to-interference noise ratio based on the received signal. A third circuit determines a relationship between elements of the sequence of estimates. A fourth circuit employs the relationship to provide a signal-to-interference noise ratio prediction for a subsequently received signal. In the illustrative embodiment, the inventive system further includes a circuit for generating a data rate request message based on the signal-to-noise ratio prediction. A special transmitter transmits the data rate request message to the external transmitter. In the specific embodiment, the relationship between elements of the sequence of estimates is based on an average of the elements of the sequence of estimates. The third circuit includes a bank of filters for computing the average. The bank of filters includes finite impulse response filters. Coefficients of the transfer functions associated with each filter in the bank of filters are tailored for different fading environments. The different fading environments include different Rayleigh fading environments, one environment associated with a rapidly moving system, a second environment associated with a slow moving system, and a third system associated with a system moving at a medium velocity. A selection circuit is connected to each of the filter banks and selects an output from one of the filters in the filter bank. The selected output is associated with a filter having a transfer function most suitable to a current fading environment.

Radio communication apparatus for receiving OFDM signal from base station and transmitting FH signal to base station, using sub-channels, base station comparing hopping pattern information items indicating hopping patterns from radio communication apparatuses including radio communication apparatus, and generating collision information when hopping patterns include colliding hopping patterns, includes estimation unit configured to estimate channel response values of sub-channels based on OFDM signal, selector which selects, from sub-channels, several sub-channels which have higher channel response values than a value, each of channel response values being expressed by power level, signal-to-noise power ratio, or signal-to-interference ratio, determination unit configured to determine hopping pattern from selected sub-channels, transmitter which transmits, to base station, hopping pattern information item indicating determined hopping pattern, receiver which receives collision information from base station, and correction unit configured to correct hopping pattern based on collision information.

A panoramic high-dynamic range (HDR) image method and system of combining multiple images having different exposures and at least partial spatial overlap wherein each of the images may have scene motion, camera motion, or both. The major part of the panoramic HDR image method and system is a two-pass optimization-based approach that first defines the position of the objects in a scene and then fills in the dynamic range when possible and consistent. Data costs are created to encourage radiance values that are both consistent with object placement (defined by the first pass) and of a higher signal-to-noise ratio. Seam costs are used to ensure that transitions occur in regions of consistent radiances. The result is a high-quality panoramic HDR image having the full available spatial extent of the scene along with the full available exposure range.

Based on a received signal y(t) received by a radiating element of an array antenna including the single radiating element and a plurality of parasitic elements, an adaptive controller calculates and sets a reactance value of a variable reactance element for directing a main beam of the array antenna in a direction of a desired wave and directing nulls in directions of interference waves so that a value of an objective function expressed by only the received signal y(t) becomes either one of the maximum and the minimum by using an iterative numerical solution of a nonlinear programming method.

System comprised of a portable medical device and method for non-contact registering at least one of electrocardiographic (ECG), magnetocardiographic (MCG), physical activity, body position, respiration, temperature, blood pressure, vasomotor activity, blood flow, neural activity, and other physiological, and health data, extracting and representing the most significant parameters from time series (trends) of said data. The system achieves the necessary sensitivity (signal-to-noise ratio) in order to miniaturize the device by collecting data of at least one fiducial point in a cardiac complex over a period of at least one, and preferably, several seconds, and extracting the underlying typical patterns from these data. Due to the miniaturization (pocket-size), the system can be implemented in a shape of a pen (or another miniature shape) that can be worn in a pocket.

A hybrid image sensor includes an infrared detector array and a CMOS readout integrated circuit (ROIC). The CMOS ROIC is coupled to at least one detector of the IR detector array, e.g., via indium bump bonding. Each pixel of the CMOS ROIC includes a first, relatively lower gain, wide dynamic range amplifier circuit which is optimized for a linear response to high light level input signals from the IR detector. Each pixel also includes a second, relatively higher gain, lower dynamic range amplifier circuit which is optimized to provide a high signal to noise ratio for low light level input signals from the IR detector (or from a second IR detector). A first output select circuit is provided for directing the output of the first circuit to a first output multiplexer. A second output select circuit is provided for directing the output of the second circuit to a second output multiplexer. Thus, separate outputs of the first and second circuits are provided for each of the individual pixel sensors of the CMOS imaging array.

Systems and methods of use involving sensors having a signal-to-noise ratio that is substantially unaffected by non-constant noise are provided for continuous analyte measurement in a host. In some embodiments, a continuous analyte measurement system is configured to be wholly, transcutaneously, intravascularly or extracorporeally implanted.

What are described herein are implantable cardiac devices such as pacemakers and defibrillators that deliver cardiac resynchronization therapy (CRT), and to a method of optimizing acquisition of impedance signals between electrodes present on implanted lead systems. This system then automatically determines which electrodes or electrode combinations acquire impedance waveforms that have the best signal to noise ratio (highest fidelity) and characterize data most representative of dysynchronous electro-mechanical events. Using closed loop algorithms which provide electrograms and a variety of impedance data reflective of the patient's clinical status, the system autonomously modifies interval timing within the CRT device.

An anti-ferromagnetically coupled, granular-continuous (“AFC-GC”) magnetic recording medium having increased thermal stability, writability, and signal-to-medium noise ratio (“SMNR”), comprising a layer stack including, in sequence from a surface of a non-magnetic substrate: (a) a continuous ferromagnetic stabilizing layer; (b) a non-magnetic spacer layer; and (c) a granular ferromagnetic recording layer; wherein: (i) the continuous ferromagnetic stabilizing and granular ferromagnetic recording layers are anti-ferromagnetically coupled across the non-magnetic spacer layer, the amount of anti-ferromagnetic coupling preselected to ensure magnetic relaxation after writing; (ii) lateral interactions in the granular, ferromagnetic recording layer are substantially completely eliminated or suppressed; and (iii) the exchange coupling strength in the continuous, ferromagnetic stabilizing layer is preselected to be slightly larger than the strength of the anti-ferromagnetic coupling provided by the non-magnetic spacer layer to thereby enhance thermal stability of the recording bits.

The present invention provides the multiuser Multiple-Input Multiple-Output (MIMO) systems with a feedback method which includes measuring, at the terminal, received Signal to Noise Ratios (SNRs) for all transmit antennas, selecting one of precoding matrixes, which has best SNRs, retrieving an index mapped to the selected preceding matrix from a predetermined mapping table, and transmitting the index with the SNRs of the selected precoding matrix. In the present invention, it is possible to reduce feedback information amount without degradation of the sum rate performance of the system since the feedback information is transmitted in a form of index implying appropriate precoding matrix and corresponding SNRs.

This invention incorporates the techniques of geophysical technology into medical imaging. Ultrasound waves are generated from multiple, simultaneous sources tuned for maximum penetration, resolution, and image quality. Digitally recorded reflections from throughout the body are combined into a file available for automated interpretation and wavelet attribute analyses. Unique points within the object are imaged from multiple positions for signal-to-noise enhancement and wavelet velocity determinations. This system describes gaining critical efficiencies by reducing equation variables to known quantities. Sources and receivers are locked in invariant, known positions. Statistically valid measurements of densities and wavelet velocities are combined with object models and initial parameter assumptions. This makes possible three-dimensional images for viewing manipulation, mathematical analyses, and detailed interpretation, even of the body in motion. The invention imposes a Cartesian coordinate system on the image of the object. This makes reference to any structure within the object repeatable and precise. Finally, the invention teaches how the recording and storing of the received signals from a whole body analysis makes a subsequent search for structures and details within the object possible without reexamining the object.

Audio frames are classified as either speech, non-transient background noise, or transient noise events. Probabilities of speech or transient noise event, or other metrics may be calculated to indicate confidence in classification. Frames classified as speech or noise events are not used in updating models (e.g., spectral subtraction noise estimates, silence model, background energy estimates, signal-to-noise ratio) of non-transient background noise. Frame classification affects acceptance / rejection of recognition hypothesis. Classifications and other audio related information may be determined by circuitry in a headset, and sent (e.g., wirelessly) to a separate processor-based recognition device.