81 results about "Coherence analysis" patented technology

Systems and methods are provided for monitoring changes in blood volume using waveforms in the peripheral vasculature. In particular, the systems and methods relate to detecting ventilation-induced variation (VIV) of waveforms in the peripheral vasculature. Advantageously, the systems and methods may relate to analyzing VIV in peripheral venous pressure (PVP). Thus, the VIV of PVP may be measured, wherein decreased VIV is indicative of decreased blood volume In exemplary embodiments, such as involving spontaneous breathing, it may be necessary to account for changes in respiratory signal strength. Thus systems and methods are also provided for assessing coherence between ventilation and VIV for a flow or pressure waveform. Specifically, coherence is evaluated by comparing the waveform to a detected respiratory signal. Finally, systems and method are provided for distinguishing the impact of respiration on the PG signal during hypervolemia as compared to hypovolemia. Such systems and methods may advantageously be utilized to monitor fluid status during fluid replacement.

An optical coherence analysis system uses a laser swept source that is constrained to operate in a mode locked condition. This is accomplished by synchronously changing the laser cavity's gain and/or phase based on the round trip travel time of light in the cavity. This improves high speed tuning by taking advantage of frequency shifting mechanisms within the cavity and avoids chaotic laser behavior.

A conjoint analysis method for electroencephalograph and electromyography signals based on autonomous movement and imagination movement comprises the steps of performing system setup, and using a LabVIEW 8.6 to generate square wave pulse signals; respectively collecting electroencephalograph signals and electromyography signals including electroencephalograph signals and electromyography signals in autonomous movement modalities and in imagination movement modalities; performing noise removal pretreatment on collected original data; performing electroencephalograph and electromyography time-domain signal analysis in the autonomous movement and imagination movement modalities on electroencephalograph and electromyography signal time-domain pictures which are performed with noise removal pretreatment in the autonomous movement and imagination movement modalities; performing time-frequency signal analysis on electroencephalograph and electromyography signals performed with noise removal pretreatment and in the autonomous movement and imagination movement modalities based on Morlet wavelet transformation; and performing partial directional coherence analysis, and in particular adopting granger causality to perform the partial directional coherence analysis. The conjoint analysis method provides new evaluation parameters for monitoring recovery auxiliary equipment and assessing organism movement level.

The invention relates to a lower limb rehabilitation robot control method and a lower limb rehabilitation robot control system based on electroencephalogram-myoelectricity signals. The lower limb rehabilitation robot control method based on the electroencephalogram-myoelectricity signals includes following steps: a, according to specific motion intention of a user, synchronously collecting corresponding electroencephalogram signals and corresponding myoelectricity signals; b, preprocessing the collected signals, and removing noise; c, extracting features of the myoelectricity signals, and establishing a motion model based on the myoelectricity signals; d, performing coherence analysis on the myoelectricity signals and the electroencephalogram signals, and building an electroencephalogram-myoelectricity classifier model; e, in rehabilitation training, collecting the electroencephalogram signals and the myoelectricity signals of the user in real time, inputting the electroencephalogram signals and the myoelectricity signals into the electroencephalogram-myoelectricity classifier model, outputting a classification result of the motion intention, and meanwhile using the motion model for verification. The lower limb rehabilitation robot control method and the lower limb rehabilitation robot control system based on the electroencephalogram-myoelectricity signals adopt the electroencephalogram-myoelectricity coherence analysis for performing clarification of lower limb motions, and meanwhile perform a contrast test on the classification result and a result of the mechanical motion model, and enhances accuracy of the classification result.

A method for analyzing relativity between electroencephalograph and myoelectricity based on autonomous and stimulation movement modalities comprises the steps of performing system setup, and using a LabVIEW 8.6 to generate synchronizing pulse signals; respectively collecting electroencephalograph signals and electromyography signals including electroencephalograph signals and electromyography signals in autonomous movement modalities and in stimulation movement modalities; analyzing electroencephalograph and electromyography time-domain signals in the autonomous movement and stimulation movement modalities according to time domain pictures of electroencephalograph and electromyography signals of a subject in the autonomous movement and stimulation movement modalities; removing noise of the electromyography signals in the stimulation modality; performing time-frequency analysis on electroencephalograph signals based on Morlet wavelet transformation; and performing coherence analysis. The method can obtain activating or restraining information of electroencephalograph in different time frequency in initiative and passive states to be used for guiding and feeding back recovery indexes of physical disability patients of apoplexy patients and the like, thereby enabling recovery to be a quantitative process instead of a qualitative definition.

The invention discloses a force-displacement hybrid control motorcycle frame fatigue test method which comprises the following steps that 1), finite element analysis is performed on a motorcycle frame, and a road load spectrum during actual running is acquired in a durability test road; 2), the road load spectrum is subjected to analysis processing and validity check, and a concentrated load spectrum is obtained; 3), a motorcycle frame assembly is mounted on a test system, and a frequency response function and a coherence function are calculated; 4), a frequency response function for calculating an excitation driving signal is constructed; and 5), a corresponding strain signal and an acceleration signal are extracted from the concentrated load spectrum, and driving signals of two vibration exciters are calculated. According to the test method, a force-displacement hybrid control mode is adopted, so that an actual stress situation of the motorcycle frame is completely matched; decoupling of a multi-axial and multi-excitation test is achieved; very high simulation precision can be obtained; and simulation points are found out by coherence analysis, and the load spectrum is concentrated, so that a test period is shortened greatly.

The invention discloses a method for obtaining a minor fault for seismic tectonic interpretation. The method comprises the steps that (a) spectral analysis is carried out on seismic data so that the spectral range of the seismic data can be obtained; (b) spectral decomposition is carried out through generalized S conversion, the parameters of fractional frequency are determined according to the spectral range obtained in the step (a); (c) high-resolution coherence analysis is carried out on high-frequency fractional frequency seismic data, middle-frequency fractional frequency seismic data and low-frequency fractional frequency seismic data by adopting a coherence method, and the coherence bodies of data bodies of different frequency bands are obtained; (d) fault lines of strata slice interpretation projection are extracted at the corresponding positions on the seismic sections of the fractional frequency seismic data bodies of the corresponding frequency bands, and the extending and spreading conditions of the fault on a time section are interpreted. According to the method for obtaining the minor fault for seismic tectonic interpretation, coherence body fault plane recognition is carried out by adopting a strata slice mode, the situation of loss, caused by tectonic reasons, of minor fault information can be eliminated, and tiny faults can be recognized more easily. The faults are interpreted on the sections of the fractional frequency seismic data bodies of the different frequency bands, the fault information of different scales can be recognized, and the interpretation of the minor fault is facilitated.

An embodiment of a method of predicting maternal hypertension during pregnancy is disclosed. The method may include measuring a maternal blood velocity waveform and measuring a fetal blood velocity waveform. The method may further include the calculation of a coherence value using a magnitude-squared coherence function between the maternal and fetal blood velocity waveforms and comparing the coherence value to a predetermined threshold value.

An optical coherence analysis system uses a laser swept source that is constrained to operate in a mode locked condition using regenerative mode-locking This is accomplished by synchronously changing the laser cavity's net gain and/or phase based on time varying intensity of the swept optical signal generated by the laser. This produces a stable pulsation behavior, which is associated with smooth tuning (low optical frequency reference clock jitter) and low relative intensity noise (RIN).

The invention relates to a fluctuation source localization method of multi-loop oscillation of a novel process industry. According to the method, a frequency domain independent component analysis (ICA) is employed to carry out independent component decomposition on industry historical process data; a variable quantity that plays a leading role in fluctuation oscillation and a dominant frequency can be screened; a local directed coherence analysis is carried out on the screened data; and a cause-and-effect relationship graph is used to visually express a cause-and-effect relationship between loop variables, so that a propagation path of a fluctuation interference can be characterized; process priori knowledge is used to simplify the cause-and-effect relationship graph as well as a threshold automatic searching mode is utilized to filter a secondary cause-and-effect relationship branch, so that a main propagation path of fluctuation is obtained and thus a fluctuation source is localized and identified. Compared with the prior art, the technology employed in the invention enables the method to have the following beneficial effects: a signal analysis on a frequency domain is utilized to reveal an essential attribute of oscillation of a multi-loop control system, so that a fluctuation source of the oscillation is determined; and thus, it is beneficial for a factory engineer to carry out follow-up maintenance and repairing work of a fault circuit.

The invention discloses a diagnosis method for a low-frequency fluid vibration excitation failure of a compressor based on axial vibration analysis. The method comprises the steps that an acquired shaft vibration signal is resolved into a direct current component and a dynamic alternating current component; then dynamic signal frequencies related to axial movement of a rotor are removed by coherence analysis; a residual frequency spectrum is continuously refined by further local frequencies; fluid impact characteristic frequency range energy in a low-frequency component is analyzed; analysis and comparison with a typical failure characteristic signal are conducted; and the low-frequency fluid vibration excitation failure can be quickly distinguished and judged. With the adoption of the method, quantification description of states of vane blades impacted by abnormal fluid is conducted with energy spectrum density of a low-frequency air flow characteristic frequency range, and the low-frequency fluid vibration excitation failure is accurately identified and quantified, tracked and monitored in real time through trend tracking analysis.

A signal processing system is described for a bilateral hearing implant system having left side and right side hearing implants. An interaural coherence analysis module receives input signals from each hearing implant including sensing microphone signals and band pass signals, and analyzes the input signals to produce an interaural coherence signal output characterizing reverberation-related similarity of the input signals. A pulse timing and coding module for each hearing implant then processes the band pass signals to develop stimulation timing signals, wherein for one or more selected band pass signals, wherein the processing includes using an envelope gating function developed from the interaural coherence signal.

The invention brings forward a test board of an automobile shock damper and a steel plate spring, a compatibility test system and a method thereof. The compatibility test system comprises the test board, a road condition analog control apparatus and a coherence analysis apparatus. The road condition analog control apparatus is used for controlling the motion of a driving oil cylinder in the test board according to a prestored road load spectrum. The coherence analysis apparatus is used for receiving an acceleration signal of the shock damper sensed by a first sensor and an acceleration signal of the steel plate spring sensed by a second sensor in the test board, carrying out coherence analysis on the acceleration signal of the steel plate spring and the acceleration signal of the shock damper, and determining that the shock damper and the steel plate spring are compatible when a result of the coherence analysis is less than a preset threshold. According to the test board, the system and the method of the invention, utilizing an empirical formula for calculation can be avoided, and raising accuracy is facilitated.

The invention discloses a coherence-nonnegative matrix factorization based multichannel myoelectricity coupling characteristic analysis method. The method comprises the steps that traditional coherence analysis is combined with nonnegative matrix factorization, multichannel electromyographic signals are collected synchronously and preprocessed, multichannel electromyographic signal coherence is calculated, and finally the function connection strength among all frequency band muscles is obtained through nonnegative matrix factorization. Accordingly, the multichannel myoelectricity coupling characteristics and the function connection strength among all the frequency band muscles are analyzed quantificationally, an effective observation method is provided for deep exploring a central nervous system motion control mechanism, and the important application value is achieved in the field of rehabilitation medicine.

An optical coherence analysis system uses a laser swept source that is constrained to operate in a mode locked condition. This is accomplished by synchronously changing the laser cavity's gain and/or phase based on the round trip travel time of light in the cavity. Many high-speed wavelength swept laser sources emit pulses synchronized with the round trip time of the cavity as part of a nonlinear optical frequency red shifting process. Stable pulsation is associated with smooth tuning and low relative intensity noise. Addition of mode-locking methods to this class of lasers can control and stabilize these lasers to a low clock jitter and RIN state, and in specific cases allow long-to-short wavelength tuning in addition to the usual short-to-long (red shifting). The laser may comprise a SOA (410), a tunable Fabry-Perot-Filter (412) as one reflector and an Output coupler (405) in an optical fiber (406) to adjust the cavity length.

A signal processing arrangement is described for signal processing in a bilateral hearing implant system having left side and right side hearing implants. An interaural coherence analysis module analyzes system input signals to produce an interaural coherence signal output characterizing reverberation-related similarity of the input signals. And a stimulation timing and coding module for each hearing implant processes band pass signals to develop stimulation timing signals based on selecting as a function of the interaural coherence signal a stimulation coding strategy from a plurality of different stimulation coding strategies including an envelope-based stimulation coding strategy based on the band pass envelope, and an event-based stimulation coding strategy based on the temporal fine structure features, producing the stimulation timing signals using the selected stimulation coding strategy, and switching between different selected stimulation coding strategies as a function of changes in the interaural coherence signal.

The invention provides a method for analyzing discourse coherence quality of an English writing. The method refers to an analysis model composed of an English writing preprocessing module, an English writing grammatical role marking module, an English writing feature extraction module, an English writing coreference resolution module, an English writing physical link network construction module and an English writing discourse coherence analysis module. After an English writing is processed by the analysis model, the discourse coherence quality analysis results of the English writing can be finally obtained. According to the method disclosed by the invention, the problem of coherence analysis of reference relation and language words in the English writing is solved, and the analysis result of the method disclosed by the invention is better than that of the traditional method for analyzing the discourse coherence quality of the English writing.

The invention discloses a device and a method for the coherent separation of the noise of the equipment of a direct-current convertor station. A sound transmission device and a laser vibration measurer are respectively arranged outside equipment to be measured, a noise signal and a vibration signal of the equipment to be measured are respectively measured by the sound transmission device and the laser vibration measurer, and coherence analysis is carried out on the noise signal and the vibration signal by a computer, i.e. the noise at the position of a frequency with large coherence value is generated by the equipment when working, and the noise at the position of a frequency with small coherence value (such as smaller than 0.8 under a given confidence) is not caused by the vibration of the equipment to be measured. The invention does not need to contact with the equipment to be measured, can remotely measure the vibration and the noise of the equipment to be measured, avoids high-voltage danger and guarantees the safety of instruments; and by utilizing the coherence between the vibration and the noise, the noise spectrum and the noise magnitude of certain equipment can be separated from a complicated place with the together radiating noise of various kinds of equipment.

The invention discloses a concrete shallow-surface-layer ultrasonic surface wave detection method based on an arrangement type ultrasonic seismic focus. The concrete shallow-surface-layer ultrasonic surface wave detection method is implemented by a seismic focus device and a receiving device and comprises three stages of data acquisition, data processing and shallow surface layer shear wave velocity calculation; in the data acquisition stage, before data acquisition is started, firstly, a detection region needs to be determined, region meshing is carried out on a to-be-detected surface according to a detection level resolution demand, and all scanning point positions are determined, then scanning is sequentially carried out on each point position, and the process is repeated until scanningon all the point positions is finished; the data processing comprises signal coherence analysis, phase extraction and average surface wave velocity calculation; and according to a data processing result, shallow surface layer shear wave velocity calculation is carried out so as to judge whether a shallow surface layer below the detection region has defects. According to the invention, a surface wave phase velocity is extracted by phase analysis and an average shear wave velocity of a shallow surface layer of concrete is estimated hereby; and on the basis of a corresponding relationship between the shear wave velocity and medium hardness, a defect region of the shallow surface layer of the concrete is detected and identified.