Abstract: A system and method for determining from an arbitrary signal a characteristic signature or other characterizing feature and for distinguishing signals associated with one specific condition from those associated with one or more other conditions. The system uses dictionaries of plural sets of basis signal elements, for example, combinations of orthogonal bases with different characteristics. It optimizes the fit of part of an arbitrary signal to one or more elements of one class of basis signals from a dictionary and iteratively fits the remainder of the arbitrary signal to elements of an optimal class of basis signals, either the original or a different class depending on the goodness of match between the residual part of the signal and the subsequent basis class.

Abstract: Disclosed herein is a method and system for calibrating line drive currents in systems that generate data signals by varying line drive currents and that interpret the data signals by comparing them to one or more reference voltages. The calibration includes varying the line drive current at a transmitting component. At different line drive currents, a receiver reference voltage is varied while the transmitting component transmits data to a receiving component. At each line drive current, the system records the highest and lowest receiver reference voltages at which data errors do not occur. The system then examines the recorded high and low receiver reference voltages to determine a desirable line drive current.

Abstract: A system, method and program product for monitoring a complex signal for ultrasensitive detection of state changes, or for signature recognition and classification is provided. A complex signal is decomposed periodically for empirical modeling. Wavelet analysis, frequency band filtering or other methods may be used to decompose the complex signal into components. A library of signature data may be referenced for selection of a recognized signature in the decomposed complex signal. The recognized signature may indicate data being carried in the complex signal. Estimated signal data may be generated for determination of an operational state of a monitored process or machine using a statistical hypothesis test with reference to the decomposed input signal.

Abstract: The present invention provides an apparatus and method for inspecting electrical continuity of a circuit board, capable of decreasing the impedance in a current path as an inspection object to achieve enhanced SN ratio. A coupling capacitance is formed at one of terminals of a pattern wire on a board as an inspection object in a non-contact manner, and an inductance (450) and a lead wire are connected to this capacitance. An AC inspection signal is applied to the other terminal through the lead wire in a contact manner. A resonance circuit is defined by the capacitance, inductance and pattern wire, and thereby an output signal can be detected with lowering the impedance.

Abstract: FFT section 102 transforms a windowed input noise signal into a frequency spectrum. Spectral model storing section 103 stores model information on spectral models. Spectral model series calculating section 104 calculates spectral model number series corresponding to amplitude spectral series of the input noise signal, using the model information stored in spectral model storing section 103. Duration model/transition probability calculating section 105 outputs model parameters using the spectral model number series calculated in spectral model series calculating section 104. It is thereby possible to synthesize a background noise with perceptual high quality.

Abstract: A method and apparatus for real-time derivation of precise digital clock edges and synchronous logic samples from a digital signal having a clock channel and at least one data channel acquires a plurality of temporally offset analog samples during each of a sequence of sample periods and from consecutive samples where there is a logic level transition estimates an edge time. From the edge times for the clock channel an offset is added and applied to the at least one data channel to determine the synchronous logic samples for the data channel at each offset clock edge time.

Abstract: The start up performance of an ultrasonic system under zero load conditions is improved by setting a phase set point in a frequency control loop such that, at start up under zero load conditions, the phase set point intersects a point on a phase-frequency response curve which has a low positive slope. This intersection point on the phase-frequency response curve changes as the load is increased and the system Q is decreased. The controller “seeks” a target 0° impedance phase angle. The frequency of the ultrasonic generator is set to an off-resonance frequency which is lower than the resonance of any known hand piece/blade combination. In order for the drive voltage to not exceed the physical limit of the system, the drive current is set to a low level. The drive frequency is then smoothly increased in steps until the target 0° impedance phase delta is located.

Abstract: A measuring apparatus includes a spectrum analysis unit having an input for receiving an input signal to be measured. The input signal includes a carrier signal located within a predetermined band of frequencies and the spectrum analysis unit is arranged to store a set of user definable parameters including the location of the carrier signal within the predetermined band of frequencies, and to use the set of user definable parameters to measure a quantity associated with the carrier signal.

Abstract: Representative embodiments are directed to systems and methods for processing analyzer trace data of a multi-tone signal to more accurately estimate the frequencies and amplitudes of the tones of the multi-tone signal. Specifically, trace data may be processed to determine peak trace points. For each identified peak point, an error minimization algorithm minimizes the sum of differences between a plurality of trace points surrounding the respective peak point and the predicted Fourier transform through a raised-cosine window of a theoretical tone. The result of the minimization algorithm identifies the amplitude and frequency of a tone of the multi-tone signal with appreciable degree of accuracy.

Abstract: The spectrum of a PCM signal is divided into bands. Combinations of a reference band inclusive of a highest frequency band and another band, one of the reference band and other band being normalized, are checked to identify a combination having a highest spectrum distribution correlation. The spectrum having the same distribution as the spectrum distribution of the reference band contained in the identified combination is scaled along an envelope function and added to a higher frequency side than the reference band to generate an output signal. A presence/absence of high frequency components of a PCM signal is detected. Only if there are high frequency components, the spectrum components are added to generate an output signal.

Abstract: A measurement system for analyzing data values that are stored in memory and that represent a sampled electrical signal under analysis (SUA). Each of the data values represents the SUA at respective points in time over a time interval during which the SUA was sampled. The stored data values constitute a main data record. The system includes processing logic that is configured to generate at least a first reduced data record from the main data record. The first reduced data record comprises a subset of the data values of the main data record. The first reduced data record is processed by the processing logic to locate an edge (i.e., a voltage transition) in the first reduced data record. Thus, it is not necessary that the main data record, which is more voluminous than the first reduced data record, be used to locate the edge.

Abstract: Digital peak detection among multiple signals, or inputs. In one embodiment, a detection method that includes receiving multiple digitized input signals. For each digitized input signal, the method also includes noting a first data value associated with the digitized input signal at a first time. The method includes comparing the first data values to determine a largest first data value from among the first data values. For each digitized input signal, the method includes noting a second data value associated with the digitized input signal at a second time. The method includes comparing the second data values to determine a largest second data value from among the second data values. The method includes comparing the largest second data value with a threshold data value. The method includes detecting a peak when the largest second data value is greater than the threshold data value, and less than the largest first data value.

Abstract: The present invention relates to a method and system for efficiently determining grating profiles using dynamic learning in a library generation process. The present invention also relates to a method and system for searching and matching trial grating profiles to determine shape, profile, and spectrum data information associated with an actual grating profile.

Abstract: A system and method of reducing cross talk in pulse oximetry signals that are attenuated by a patient tissue site are provided. In one embodiment, Red and IR LEDs of a pulse oximeter are separately excited (1010) and the respective Red and IR data vectors output by the detector are measured (1020). The Red and IR data vectors are normalized (1030). Red to IR and IR to Red cross talk vectors are computed (1040). Red and IR demodulation vectors are obtained by subtracting (1050) the respective Red and IR cross talk vectors from the respective normalized Red and IR data vectors. The demodulation vectors are normalized (1060), scaled (1070), and the magnitudes of the Red and IR signal components are obtained by computing (1080) the dot product of the composite signal data vector with the normalized and scaled Red demodulation and IR demodulation vectors, respectively.

Abstract: An improved method and system for solving a combinatorial optimization problem, such as a tracking problem, to define a plurality of associations of measurements taken of a plurality of objects is provided. In one aspect, a method, a system and a computer program product are provided for constructing a plurality of updated tracks by solving a Lagrangian dual in which each of the measurement constraints has been relaxed. In another aspect, a hybrid branch and bound and LR technique is provided to select a plurality of updated tracks from among a plurality of candidate tracks having respective initial costs. In this regard, a search tree of the candidate tracks is ordered based upon the initial costs of the candidate tracks as adjusted by the dual variables that have been defined as a result of solving a Lagrangian dual.

Abstract: System and method for characterizing a Gaussian pulse in a signal. The system includes a computer operable to receive the signal, determine a set of estimated parameters for the Gaussian pulse using a “zoom-in” approach, permute the estimated parameter set to generate one or more permuted parameter sets, where the estimated and permuted parameter sets each represent a corresponding waveform, generate closed form inner products between the received signal and each waveform, generate linear equations from the inner products, each linear equation being a function of a respective one of the parameter sets and corresponding parameter variables for the Gaussian pulse, and determine values for the parameter variables by solving the linear equations. The determined parameters characterize the Gaussian pulse. If there are N parameters to determine and M permutations generated, where M is greater than or equal to N, M+1 linear equations are solved to overdetermine the N parameters.

Abstract: This invention unifies a set of statistical signal processing, neuromorphic systems, and microelectronic implementation techniques for blind separation and recovery of mixed signals. A set of architectures, frameworks, algorithms, and devices for separating, discriminating, and recovering original signal sources by processing a set of received mixtures and functions of said signals are described. The adaptation inherent in the referenced architectures, frameworks, algorithms, and devices is based on processing of the received, measured, recorded or otherwise stored signals or functions thereof. There are multiple criteria that can be used alone or in conjunction with other criteria for achieving the separation and recovery of the original signal content from the signal mixtures. The composition adopts both discrete-time and continuous-time formulations with a view towards implementations in the digital as well as the analog domains of microelectronic circuits.

Abstract: A system for analyzing the behavior of electronic devices includes a first database for storing simulation values and a second database for storing actual waveform values. The system further includes software for aligning the values stored in the first and second databases, so that simulated and actual values can be readily compared. Analysis tools are included for examining similarities and differences between simulated and actual behavior.

Abstract: A frequency detector includes a slicer to receive and slice a phase error against a compare threshold value. The slicer generates a symbol based on the phase error sliced against the compare threshold value. A symbol counter is provided to increment a symbol count if the symbol generated is the same as a last symbol. A logic circuit compares the symbol count with a symbol count limit if the symbol is different from the last symbol. The logic circuit increments a high counter and clears a low counter if the symbol count is less than the symbol count limit. The logic circuit increments the low counter and clears the high counter if the symbol count is greater than the symbol count limit. A combinational logic circuit is provided to generate a high frequency jitter true signal or a high frequency jitter false signal based on at least one of the symbol count, the high counter, and the low counter.

Abstract: Failures associate with bad hand pieces and blade failures in an ultrasonic surgical system are distinguished by monitoring the rate of change of the resonance frequency and the rate of change of the resonance impedance of the hand piece/blade as the drive frequency is changed. As the system reaches resonance, the control system locks onto the resonance frequency. When a loss of lock occurs with no recovery, the rate of change of the frequency and rate of change of the impedance are compared to obtain the fastest rate of change which is stored in non-volatile memory of the ultrasonic generator. If the rates of change are higher than normal rates of change due to temperature changes with the longest blades, a “Bad Blade” message is displayed on an LCD.

Abstract: A method according to which a discrete waveform is multiplied by a sine function having an arbitrary period. The product is summed over a selected interval to derive a first summation and multiplied by a cosine function having the same period and the product is summed over the interval to provide a second summation. The sine and cosine functions are multiplied together and the product is summed over the interval to provide a third summation. The sine function is squared and summed over the interval to provide a fourth summation. Similarly, the cosine function is squared and summed over the interval to provide a fifth summation. Based on the five values, sinusoids contained in the discrete waveform are detected by subtracting each sinusoid from the discrete waveform to provide an associated residual waveform and detecting each residual waveform whose power is a local minimum as a result of varying the period.

Abstract: A correlation function measuring method and apparatus can correct a correlation vector with high accuracy. The correlation function measuring apparatus includes first signal processing means 18a to 22a for processing a first monitored signal to give a first spectrum, second signal processing means 18b to 22b for processing a second monitored signal to give a second spectrum, correction value computing means 26 for inputting correction signals to the first and second signal processing means to give correction values corresponding to respective frequencies, based on the first spectrum and the second spectrum, and correlation function computing means 30 for obtaining a correlation function between the first spectrum and the second spectrum by using correction values given by the correction value computing means.

Abstract: An apparatus and method that tests an NMR system, including MRI scanners, by taking H-B measurements for the apparatus at any stage during the manufacture thereof, to thereby detect any defects of the NMR system at any point during the manufacture thereof.

Abstract: A time stamping method for threshold crossing points of an input signal uses a dithered threshold level. Digital data samples are acquired for the input signal and time marks are determined for the threshold crossings using interpolation. The time marks are stores as the time stamps. A threshold offset value generator generates a distribution of offset values for dithering the threshold value. Time interval values are generated from the time stamps and the number of occurrences of time interval values are accumulated in time bins. A time interval distribution histogram and statistical time interval distribution data, such as the mean, standard deviation and minimum and maximum time intervals may be generated.

Abstract: A pulse oximeter (100) includes two or more light sources (102) for transmitting optical signals through an appendage (103) of patient. The sources (102) are operated to transmit code division multiplexed (CDM) signals. That is, the sources (102) are driven by drives (104) in response to signals from a digital processing unit (116) such that the sources (102) are modulated using different code sequences. The code sequences are preferably non-periodic and may be orthogonal to one another. The use of such CDM signals provides certain advantages related to noise reduction.

Abstract: The start up performance of an ultrasonic system under zero load conditions is improved by setting a phase set point in a frequency control loop such that, at start up under zero load conditions, the phase set point intersects a point on a phase-frequency response curve which has a low positive slope. This intersection point on the phase-frequency response curve changes as the load is increased and the system Q is decreased. The controller “seeks” a target 0° impedance phase angle. The frequency of the ultrasonic generator is set to an off-resonance frequency which is lower than the resonance of any known hand piece/blade combination. In order for the drive voltage to not exceed the physical limit of the system, the drive current is set to a low level. The drive frequency is then smoothly increased in steps until the target 0° impedance phase delta is located.

Abstract: A phase detector with a linear gain characteristic includes two exclusive-OR gates with inputs connected to an input signal and an inverted input signal and a reference signal in a phase locked loop. The outputs of the exclusive-OR gates are connected to a plurality of switches. The switches are connected to a plurality of resistors and the resistors are connected together to form an output signal. Switches and resistors are selected in complementary pairs by a gain select function to provide a linear gain characteristic for the output signal.

Abstract: A method and apparatus for spectral analysis of a sampled signal are provided. According to the method, a first time interval &Dgr;T is determined which represents a sample set over which the signal can be averaged for purpose of decomposing the signal into instantaneous mean and random components. From random component of the signal, the optimal time-dependent time interval AW over which the random component should be averaged to obtain the instantaneous frequency spectrum (IFS) is then calculated based upon the instantaneous signal memory. Signal memory specifies the extent in time beyond which the signal “forgets” its past behavior and thus is a measure of its degree-of-randomness. Defining AW in this way reduces the likelihood that short-lived events are lost (or masked) due to uncharacteristically short (or long) averaging intervals. Importantly, both time intervals &Dgr;T and AW are dynamic and vary randomly with time.

Abstract: A tone detector includes at least one circuit (hereinafter “single phase reference matcher”) that not only performs a convolution of an input signal with a reference signal, but also compares the result of convolution with a threshold to determine if there is a match, and if so drives a signal active indicating that tone is present. If there is no match, another circuit (hereinafter “phase shifter”) delays the reference signal by a fraction (e.g. ⅛) of the measuring period, thereby to introduce a phase shift (e.g. &pgr;/8) between the input signal and the reference signal. The “single phase reference matcher” again performs the just-described operation, this time with a delayed reference signal, and repeats the operation as often as necessary (e.g. eight times) to cycle through the entire measuring period, thereby to ensure that tone (if present in the input signal) is detected irrespective of phase, during one of the operations.

Abstract: A method and system for detecting a coherent signal of unknown frequency from an incoming electrical signal comprising a multiplicity of frequencies is disclosed. A time sequence of sample data signals generated from the incoming electrical signal is decomposed into a plurality of frequency range signals using wavelet functions. The coherent signal is detected in the time sequence based on the frequency range signals. In one embodiment, a program gate array is used to process the time sequence of data samples using wavelet functions. In another embodiment, the data samples are decomposed using Haar scaling and wavelet functions to form smoothed and detailed components of the frequency range signals. The frequency range signals may be compared to at least one predetermined threshold signal to detect the coherent signal in the time sequence of sample data signals.

Abstract: An improved method and apparatus for identifying peaks and for determining the boundaries of those peaks, and boundaries of multiple peaks and shoulders within chromatograms. The method and apparatus effects real time identification and determination of the boundaries of these peaks for the purpose of fraction collection. The method and apparatus determines the boundary of a peak within a detector response profile that comprises data points plotted graphically on an X and Y-axis wherein the X-axis represents a first variable and the Y-axis represents a second variable, each variable having a value. The plot at each of the data points has a slope. Data points having a slope which deviates from a consistent value define a peak, and data points having a slope with a consistent value define a baseline.

Abstract: A time domain data converter with output frequency domain conversion. A data conversion circuit is operable to receive a signal in the time domain and provide an output in the frequency domain. It includes a data converter for converting data from an analog format to a digital format in the time domain. It also includes a processor for processing the data in the digital format output from the data converter through a time domain/frequency domain transform to provide data in the digital format in the frequency domain. The output of the frequency domain operation or the time domain operation can be provided for output in response to the generation of a data ready signal.

Abstract: A process for identifying and rejecting pile-up pulses in a system is provided. Preferably, the process is applied to mine detection where time is at a premium. A thermal neutron activator sensor (TNA) trails a mine-detecting vehicle and is dwells over the coordinates of a target of interest for a short a time as possible. The TNA interrogates the object with slow neutrons, the required time being brief due to the use of a strong source coupled with a the process for analyzing the resultant high number and rate of pulses and rejecting piled-up pulses. Specifically, low energy pulses are removed and the remaining pulse is analyzed for its shape in comparison to the known shape of a non-piled-up pulse. The pulse is integrated using a gated integrator between a designated portion the pulse and for the whole pulse. For a normal pulse, the difference between the two integrations produces a repeatable baseline which is zeroed out to a null difference.

Abstract: A method of determining peaks in a discrete function. The method comprising the steps of: applying a closing function to the discrete function to generate a closed discrete function; defining peaks within the closed discrete function; sorting the defined peaks according to function value; and applying a threshold value to each sorted defined peak in individual succession, wherein sorted defined peaks having a peak height value above the threshold value are retained within the closed discrete function.

Abstract: A computer-implemented modeling tool for cellular telephone systems predicts signal strength under real conditions by considering the effects of terrain and man-made structures on transmitted signals. The modeling tool gives more accurate predictions under line of sight conditions, when obstructions occur due to terrain contours, and when mobile or transmitter antennas are blocked by buildings or other structures.

Abstract: A self-framing serial trigger within an oscilloscope or specialized analyzer construes an absence of the data's clock signal for at least a selected length of time as implying the occurrence of a framing signal. This frees the serial trigger from otherwise needing an externally supplied framing signal. The serial trigger may include a shift register containing the most recent N-bits of the data, which is then bit-wise compared to the trigger pattern (stored in a register). This level of comparison may provide for don't care bits in the trigger pattern. The results of this bit-wise comparison are then inspected for a certain uniformity indicating that the trigger pattern has been matched. An additional circuit may count clock signals since the last implied framing pulse. If this additional count has not yet reached M (or counted down from M to zero) the match is premature, and no trigger signal is generated.