Patent application number | Description | Published |
20090324033 | Signal Processing Systems and Methods for Determining Slope Using an Origin Point - The present disclosure relates to signal processing and, more particularly, relates to determining the slope of a signal. In embodiments, slopes between an origin point of the plot and at least two points in the signal may be determined. The slopes may be used to generate a histogram, and a desired slope of the signal corresponding to a preferred value in the histogram may be selected. In an embodiment, a two-dimensional Lissajous figure may be selected from a three-dimensional Lissajous figure and a histogram of the slopes within the selected Lissajous figure may be created to determine the desired slope. The desired slope may have clinical relevance (e.g., it may be used to determine a patient's blood oxygen saturation level). The three-dimensional Lissajous figure may be derived from surface signals related to two scalograms. Each scalogram may be the result of performing a continuous wavelet transform on a signal. A confidence measure may be generated with respect to determining the desired slope. | 12-31-2009 |
20100013642 | Systems And Methods For Evaluating A Physiological Condition - A method and system are provided for evaluating in patient monitoring whether a signal is sensed optimally by receiving a signal, transforming the signal using a wavelet transform, generating a scalogram based at least in part on the transformed signal, identifying a pulse band in the scalogram, identifying a characteristic of the pulse band, determining, based on the characteristic of the pulse band, whether the signal is sensed optimally; and triggering an event. The characteristics of the pulse band and scalogram may be used to provide an indication of monitoring conditions. | 01-21-2010 |
20100014723 | SIGNAL PROCESSING SYSTEMS AND METHODS USING MULTIPLE SIGNALS - According to embodiments, techniques for signal processing using multiple signals are disclosed. A first scalogram may be generated from a first signal and a second scalogram may be generated from a second signal. A modified or masked scalogram may then be generated based on the first and second scalograms. The modified scalogram may then be used to determine at least one physiological parameter. In some embodiments, one or both of the first signal and the second signal may be photoplethysmograph (PPG) signals obtained from a pulse oximeter. | 01-21-2010 |
20100014724 | SIGNAL PROCESSING SYSTEMS AND METHODS USING BASIS FUNCTIONS AND WAVELET TRANSFORMS - According to embodiments, systems and methods are provided that use continuous wavelet transforms and basis functions to provide an optimized system for the determination of physiological information. In an embodiment, the basis functions may be used to refine an area of interest in the signal in frequency or in time, and the continuous wavelet transform may be used to identify a maxima ridge in the scalogram at scales with characteristic frequencies proximal to the frequency or frequencies of interest. In another embodiment, a wavelet transform may be used to identify regions of a signal with the morphology of interest while basis functions may be used to focus on these regions to determine or filter information of interest. In yet another embodiment, basis functions and continuous wavelet transforms may be used concurrently and their results combined to form optimized information or a confidence metric for determined physiological information. | 01-21-2010 |
20100014725 | Systems And Methods For Filtering A Signal Using A Continuous Wavelet Transform - According to embodiments, systems and methods for reducing noise in a signal are provided. A signal may be transformed using a continuous wavelet transform and a corresponding scalogram may be generated. Regions of noise may be identified from the resulting scalogram. These regions may be masked by, for example, removing, altering, or appropriately tagging the regions. After masking the regions of noise, the scalogram may be converted to a filtered signal using an inverse wavelet transform. Alternatively or additionally, desirable regions of non-noise may instead be identified from the resulting scalogram. These desirable regions may be extracted from the scalogram and an inverse wavelet transform performed on the extracted regions in order to generate a filtered signal. | 01-21-2010 |
20100016676 | Systems And Methods For Adaptively Filtering Signals - According to embodiments, systems and method are provided for adaptively filtering signals. A combination of filtering techniques is described in which non-wavelet based filtering techniques are used with wavelet-based filtering techniques to filter an input signal. One or more physiological parameters may then be determined from the filtered output signal. | 01-21-2010 |
20100016680 | Signal Processing Systems and Methods for Analyzing Multiparameter Spaces to Determine Physiological States - The present disclosure relates to signal processing systems and methods, and more particularly, to systems and methods for analyzing multiparameter spaces to determine changes in a physiological state. In embodiments, a first signal and a second signal may be obtained, from which a first plurality of values of a physiological parameter may be determined. At least one of the signals also may be used to generate a scalogram derived at least in part from the signal. A second plurality of values may be determined based at least in part on a feature in the scalogram. The first and second plurality of values may then be associated, and a physiological state may be analyzed using the associated first and second values. In an embodiment, the signals may be PPG signals and the associated first and second values may include a parameter scatter plot that may permit a user to determine changes in a patient's ventilation state over time. | 01-21-2010 |
20100016691 | Methods And Systems For Determining Whether To trigger An Alarm - According to embodiment, systems and methods for processing a physiological measurement and generating alarms based on the measurement are provided. Multiple features of a single physiological measurement may be concurrently monitored to generate alarms. One or more of the features may be based on a trend of the physiological measurement. One or more of the features may be based on a wavelet transform of the physiological measurement. Different features may be used in different combinations to lower the percentage of false alarms while still recognizing valid alarm events. | 01-21-2010 |
20100016692 | SYSTEMS AND METHODS FOR COMPUTING A PHYSIOLOGICAL PARAMETER USING CONTINUOUS WAVELET TRANSFORMS - According to embodiments, systems and methods for computing a physiological parameter are provided. The physiological parameter may be calculated using a continuous wavelet transform technique as well as using a non-continuous wavelet transform technique. More than one value for the physiological parameter may be calculated using various techniques. The values may be evaluated to select a desired value, or an average or weighted average of the values may be computed to generate a desired value. | 01-21-2010 |
20100016693 | Systems And Methods For Identifying Pulse Rates - According to embodiments, techniques for using continuous wavelet transforms and spectral transforms to identify pulse rates from a photoplethysmographic (PPG) signal are disclosed. According to embodiments, candidate pulse rates of the PPG signal may be identified from a wavelet transformed PPG signal and a spectral transformed PPG signal. A pulse rate may be determined from the candidate pulse rates by selecting one of the candidate pulse rates or by combining the candidate pulse rates. According to embodiments, a spectral transform of a PPG signal may be performed to identify a frequency region associated with a pulse rate of the PPG signal. A continuous wavelet transform of the PPG signal at a scale corresponding to the identified frequency region may be performed to determine a pulse rate from the wavelet transformed signal. | 01-21-2010 |
20100016695 | Methods And Systems For Filtering A Signal According To A Signal Model And Continuous Wavelet Transform Techniques - According to embodiments, systems and methods are provided for filtering a signal. A first reference signal may be generated according to a signal model and a second reference signal may be generated by analyzing a continuous wavelet transform of a signal The first and second reference signals may then both be applied to an input signal to filter the input signal according to the components of both of the reference signals. | 01-21-2010 |
20100016696 | SYSTEMS AND METHODS FOR GENERATING REFERENCE SIGNALS - According to embodiments, systems and methods for generating reference signals are provided. A signal may be transformed using a continuous wavelet transform, Regions of interest may be selected from a transform or the resulting scalogram that may be used to generate a reference signal to use in filtering the signal or other signals. Cross-correlation techniques may be used to cancel noise components or isolate non-noise components from the signal. A physiological parameter may then be determined from the filtered signal or isolated components in the signal. | 01-21-2010 |
20100016734 | Systems and Methods Using Induced Perturbation to Determine Physiological Parameters - According to embodiments, systems and methods for non-invasive blood pressure monitoring are disclosed. An exciter may induce perturbations in a subject, and a sensor or probe may be used to obtain a detected signal from the subject. The detected signal may then be used to measure one or more physiological parameters of the patient. For example if the perturbations are based on a known signal, any differences between the known signal and the input signal may be attributable to the patient's physiological parameters. A phase drift between the perturbation signal and the detected signal may be determined from a comparison of the scalograms of the exciter location and the sensor or probe location. From the scalogram comparison, more accurate and reliable physiological parameters may be determined. | 01-21-2010 |
20100016738 | SYSTEMS AND METHODS FOR PULSE PROCESSING - According to embodiments, techniques for using continuous wavelet transforms to process pulses from a photoplethysmographic (PPG) signal are disclosed. The continuous wavelet transform of the PPG signal may be used to identify and characterize features and their periodicities within a signal. Regions, phases and amplitudes within the scalogram associated with these features may then be analyzed to identify, locate, and characterize a true pulse within the PPG signal. Having characterized and located the pulse in the PPG (possibly also using information gained from conventional pulse processing techniques such as, for example, by identifying turning points for candidate pulse maxima and minima on the PPG, frequency peak picking for candidate scales of pulses, etc.), the PPG may be parameterized for ease of future processing. | 01-21-2010 |
20100017142 | Low Perfusion Signal Processing Systems And Methods - In some embodiments, systems and methods for identifying a low perfusion condition are provided by transforming a signal using a wavelet transform to generate a scalogram. A pulse band and adjacent marker regions in the scalogram are identified. Characteristics of the marker regions are used to detect the existence of a lower perfusion condition. If such a condition is detected, an event may be triggered, such as an alert or notification. | 01-21-2010 |
20100079279 | Detecting a Signal Quality Decrease in a Measurement System - Techniques for detecting a signal quality decrease are disclosed. A sensor or probe may be used to obtain a plethysmograph or photoplethysmograph (PPG) signal from a subject. A wavelet transform of the signal may be performed and a scalogram may be generated based at least in part on the wavelet transform. One or more characteristics of the scalogram may be determined. The determined characteristics may include, for example, energy values and energy structural characteristics in a pulse band, a mains hum band, and/or a noise band. Such characteristics may be analyzed to produce signal quality values and associated signal quality trends. One or more signal quality values and signal quality trends may be used to determine if a signal quality decrease has occurred or is likely to occur. | 04-01-2010 |
20100081892 | Systems and Methods for Combined Pulse Oximetry and Blood Pressure Measurement - The present disclosure relates to pulse oximetry measurements and, more particularly, relates to a combined sensor that includes a pulse oximetry (SpO | 04-01-2010 |
20100081898 | Detecting A Probe-Off Event In A Measurement System - According to embodiments, techniques for detecting probe-off events are disclosed. A sensor or probe may be used to obtain a plethysmograph or photoplethysmograph (PPG) signal from a subject. A wavelet transform of the signal may be performed and a scalogram may be generated based at least in part on the wavelet transform. One or more characteristics of the scalogram may be determined. The determined characteristics may include, for example, an energy decrease, a broadscale high-energy cone, a regular, repeated high-scale pattern, a low-scale information pattern; and a pulse band. The absence or presence of these and other characteristics, along with information about the characteristics, may be analyzed to detect a probe-off event. A confidence indicator may be calculated in connection with probe-off event detections and alarms may be generated when probe-off events occur. | 04-01-2010 |
20100081944 | Systems and Methods for Recalibrating a Non-Invasive Blood Pressure Monitor - Techniques for non-invasive blood pressure monitoring are disclosed. Data corresponding to a patient may be received from a hospital information system. The data may include, for example, drug administration data, medical procedure data, medical equipment data, or a combination thereof. Whether a blood pressure monitoring system needs to be recalibrated may be determined, based at least in part on the received data. If it is determined that the blood pressure monitoring system needs to be recalibrated, the recalibration may be performed and at least one blood pressure measurement of the patient may be computed using the recalibrated blood pressure monitoring system. | 04-01-2010 |
20100298728 | Signal Processing Techniques For Determining Signal Quality Using A Wavelet Transform Ratio Surface - According to embodiments, a wavelet transform ratio surface measure signal may be generated from two PPG signals. Values of the wavelet transform ratio surface measure signal at a given moment of time (i.e., instantaneous values) may be indicative of localized signal discrepancies within and/or between the PPG signals such as noise and signal artifacts. Spikes in the instantaneous values of the wavelet transform ratio surface measure signal may be located and used to determine a signal quality measure for the PPG signals. Characteristics of the spikes such as number, location, grouping, distribution, amplitude, and polarity may be used in the signal quality determination. | 11-25-2010 |
20100324431 | Determining Disease State Using An Induced Load - The present disclosure relates to determining a patient's disease state based at least in pail on obtaining or determining certain underlying characteristics, such as vasotone, venous compliance, or ability of the vascular system to drain venous blood, of the patient's vascular system. The characteristics may be obtained by analyzing changes to a patient signal, such as the overall signal change, the rate of change, the shape of the change, changes in signal energy, or changes in the baseline and/or the amplitude of the signal, and/or the time period(s) over which the signal changes, that are caused by inducing a load on the vascular system. In some embodiments, the signal changes may be analyzed by transforming the signal using, for example, a continuous wavelet transform. The patient's health status or disease state may be determined using the one or more vascular system characteristics that influenced the signal change. | 12-23-2010 |
20100324827 | Fluid Responsiveness Measure - A method and system for measuring fluid responsiveness of a patient is disclosed. Information related to fluid responsiveness of a patient may be derived from a PPG signal, for example, by analyzing the PPG signal transformed by a continuous wavelet transform. Other techniques for deriving information related to fluid responsiveness of a patient include, for example, analyzing the amplitude modulation, frequency modulation, and/or baseline changes of a PPG signal. | 12-23-2010 |
20110004069 | Systems And Methods For Processing Physiological Signals In Wavelet Space - Methods and systems are disclosed for analyzing multiple scale bands in the scalogram of a physiological signal in order to obtain information about a physiological process. An analysis may be performed to identify multiple scale bands that are likely to contain the information sought. Each scale band may be assessed to determine a band quality, and multiple bands may be combined based on the band quality. Information about a physiological process may determined based on the combined band. In an embodiment, analyzing multiple scale bands in a scalogram arising from a wavelet transformation of a photoplethysmograph signal may yield clinically relevant information about, among other things, the blood oxygen saturation of a patient. | 01-06-2011 |
20110026784 | Systems And Methods For Determining Physiological Information Using Selective Transform Data - According to embodiments, a pulse band region is identified in a wavelet scalogram of a physiological signal (e.g., a plethysmograph or photoplethysmograph signal). Components of the scalogram at scales larger than the identified pulse band region are then used to determine a baseline signal in wavelet space. The baseline signal may then be used to normalize the physiological signal. Physiological information may be determined from the normalized signal. For example, oxygen saturation may be determined using a ratio of ratios or any other suitable technique. | 02-03-2011 |
20110028810 | Systems And Methods For Resolving The Continuous Wavelet Transform Of A Signal - According to an embodiment, techniques for estimating scalogram energy values in a wedge region of a scalogram are disclosed. A pulse oximetry system including a sensor or probe may be used to receive a photoplethysmograph (PPG) signal from a patient or subject. A scalogram, corresponding to the obtained PPG signal, may be determined. In an approach, energy values in the wedge region of the scalogram may be estimated by performing convolution-based or convolution-like operations on the obtained PPG signal, or a transformed version thereof, and the scalogram may be updated according to the estimated values. In an approach, a deskewing technique may be used to align data prior to adding the data to the scalogram. In an approach, one or more signal parameters may be determined based on the resolved and estimated values of the scalogram. | 02-03-2011 |
20110028813 | Systems And Methods For Estimating Values Of A Continuous Wavelet Transform - According to embodiments, techniques for estimating scalogram energy values in a wedge region of a scalogram are disclosed. A pulse oximetry system including a sensor or probe may be used to receive a photoplethysmograph (PPG) signal from a patient or subject. A scalogram, corresponding to the obtained PPG signal, may be determined. In an arrangement, energy values in the wedge region of the scalogram may be estimated by calculating a set of estimation locations in the wedge region and estimating scalogram energy values at each location. In an arrangement, scalogram energy values may be estimated based on an estimation scheme and by combining scalogram values in a vicinity region. In an arrangement, the vicinity region may include energy values in a resolved region of the scalogram and previously estimated energy values in the wedge region of the scalogram. In an arrangement, one or more signal parameters may be determined based on the resolved and estimated values of the scalogram. | 02-03-2011 |
20110071406 | Determining A Characteristic Respiration Rate - The present disclosure relates to monitoring a characteristic respiration rate of a patient based at least in part on a suitable time period that either precedes or follows a triggering event, such as a clinician/patient interaction, where the triggering event may negatively impact the physiological parameter. In some embodiments, physiological parameter values falling between one or more pre-set thresholds may be used to derive the characteristic physiological parameter. In some embodiments, monitoring the respiration rate may provide additional information about the patient's status. In some embodiments, confidence measures may be associated with, or may be used to analyze features of the patient signal to derive information about, the characteristic respiration rate. The patient signal used to derive a patient's respiration rate may be of an oscillatory nature or may include oscillatory features that may be analyzed to derive a characteristic respiration rate. | 03-24-2011 |
20110077484 | Systems And Methods For Identifying Non-Corrupted Signal Segments For Use In Determining Physiological Parameters - According to embodiments, non-corrupted signal segments are detected by a data modeling processor implementing an artificial neural network. The neural network may be trained to detect artifact in the signal (e.g., a PPG signal or some wavelet representation of a PPG signal) and gate valid signal segments for use in determining physiological parameters, such as, for example, pulse rate, oxygen saturation, pulse rate, respiration rate, and respiratory effort. When an artifact is detected, previously received known-good signal segments may be buffered and replace the signal segment or segments containing artifact. A regression analysis may also be performed in order to extrapolate new data from previously received known-good signal segments. In this way, more accurate and reliable physiological parameters may be determined. | 03-31-2011 |
20110307184 | LOW PERFUSION SIGNAL PROCESSING SYSTEMS AND METHODS - In some embodiments, systems and methods for identifying a low perfusion condition are provided by transforming a signal using a wavelet transform to generate a scalogram. A pulse band and adjacent marker regions in the scalogram are identified. Characteristics of the marker regions are used to detect the existence of a lower perfusion condition. If such a condition is detected, an event may be triggered, such as an alert or notification. | 12-15-2011 |
20120278001 | Signal Procesing Systems and Methods Using Basis Functions and Wavelet Transforms - According to embodiments, systems and methods are provided that use continuous wavelet transforms and basis functions to provide an optimized system for the determination of physiological information. In an embodiment, the basis functions may be used to refine an area of interest in the signal in frequency or in time, and the continuous wavelet transform may be used to identify a maxima ridge in the scalogram at scales with characteristic frequencies proximal to the frequency or frequencies of interest. In another embodiment, a wavelet transform may be used to identify regions of a signal with the morphology of interest while basis functions may be used to focus on these regions to determine or filter information of interest. In yet another embodiment, basis functions and continuous wavelet transforms may be used concurrently and their results combined to form optimized information or a confidence metric for determined physiological information. | 11-01-2012 |
20120283536 | Signal Procesing Systems and Methods Using Basis Functions and Wavelet Transforms - According to embodiments, systems and methods are provided that use continuous wavelet transforms and basis functions to provide an optimized system for the determination of physiological information. In an embodiment, the basis functions may be used to refine an area of interest in the signal in frequency or in time, and the continuous wavelet transform may be used to identify a maxima ridge in the scalogram at scales with characteristic frequencies proximal to the frequency or frequencies of interest. In another embodiment, a wavelet transform may be used to identify regions of a signal with the morphology of interest while basis functions may be used to focus on these regions to determine or filter information of interest. In yet another embodiment, basis functions and continuous wavelet transforms may be used concurrently and their results combined to form optimized information or a confidence metric for determined physiological information. | 11-08-2012 |
20120302895 | METHODS AND SYSTEMS FOR FILTERING A SIGNAL ACCORDING TO A SIGNAL MODEL AND CONTINUOUS WAVELET TRANSFORM TECHNIQUES - According to embodiments, systems and methods are provided for filtering a signal. A first reference signal may be generated according to a signal model and a second reference signal may be generated by analyzing a continuous wavelet transform of a signal. The first and second reference signals may then both be applied to an input signal to filter the input signal according to the components of both of the reference signals. | 11-29-2012 |
20130012792 | SYSTEMS AND METHODS FOR IDENTIFYING PULSE RATES - According to embodiments, techniques for using continuous wavelet transforms and spectral transforms to identify pulse rates from a photoplethysmographic (PPG) signal are disclosed. According to embodiments, candidate pulse rates of the PPG signal may be identified from a wavelet transformed PPG signal and a spectral transformed PPG signal. A pulse rate may be determined from the candidate pulse rates by selecting one of the candidate pulse rates or by combining the candidate pulse rates. According to embodiments, a spectral transform of a PPG signal may be performed to identify a frequency region associated with a pulse rate of the PPG signal. A continuous wavelet transform of the PPG signal at a scale corresponding to the identified frequency region may be performed to determine a pulse rate from the wavelet transformed signal. | 01-10-2013 |
20130041240 | Methods and Systems for Discriminating Bands in Scalograms - The present disclosure is directed towards embodiments of systems and methods for discriminating (e.g., masking out) scale bands that are determined to be not of interest from a scalogram derived from a continuous wavelet transform of a signal. Techniques for determining whether a scale band is not of interest include, for example, determining whether a scale band's amplitude is being modulated by one or more other bands in the scalogram. Another technique involves determining whether a scale band is located between two other bands and has energy less than that of its neighboring bands. Another technique involves determining whether a scale band is located at about half the scale of another, more dominant (i.e., higher energy) band. | 02-14-2013 |
20130046156 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046157 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046160 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046161 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046184 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046185 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046186 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046187 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component. | 02-21-2013 |
20130046188 | METHOD OF ANALYZING AND PROCESSING SIGNALS - A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyze the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyzer component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyzer component. | 02-21-2013 |
20130127621 | Methods and Systems for Determining Whether to Trigger an Alarm - According to embodiment, systems and methods for processing a physiological measurement and generating alarms based on the measurement are provided. Multiple features of a single physiological measurement may be concurrently monitored to generate alarms. One or more of the features may be based on a trend of the physiological measurement. One or more of the features may be based on a wavelet transform of the physiological measurement. Different features may be used in different combinations to lower the percentage of false alarms while still recognizing valid alarm events. | 05-23-2013 |
20130138357 | SYSTEMS AND METHODS FOR EVALUATING A PHYSIOLOGICAL CONDITION - A method and system are provided for evaluating in patient monitoring whether a signal is sensed optimally by receiving a signal, transforming the signal using a wavelet transform, generating a scalogram based at least in part on the transformed signal, identifying a pulse band in the scalogram, identifying a characteristic of the pulse band, determining, based on the characteristic of the pulse band, whether the signal is sensed optimally; and triggering an event. The characteristics of the pulse band and scalogram may be used to provide an indication of monitoring conditions. | 05-30-2013 |
20130197329 | Systems And Methods For Estimating Values Of A Continuous Wavelet Transform - According to embodiments, techniques for estimating scalogram energy values in a wedge region of a scalogram are disclosed. A pulse oximetry system including a sensor or probe may be used to receive a photoplethysmograph (PPG) signal from a patient or subject. A scalogram, corresponding to the obtained PPG signal, may be determined. In an arrangement, energy values in the wedge region of the scalogram may be estimated by calculating a set of estimation locations in the wedge region and estimating scalogram energy values at each location. In an arrangement, scalogram energy values may be estimated based on an estimation scheme and by combining scalogram values in a vicinity region. In an arrangement, the vicinity region may include energy values in a resolved region of the scalogram and previously estimated energy values in the wedge region of the scalogram. In an arrangement, one or more signal parameters may be determined based on the resolved and estimated values of the scalogram. | 08-01-2013 |
20130229285 | DETECTING A SIGNAL QUALITY DECREASE IN A MEASUREMENT SYSTEM - Techniques for detecting a signal quality decrease are disclosed. A sensor or probe may be used to obtain a plethysmograph or photoplethysmograph (PPG) signal from a subject. A wavelet transform of the signal may be performed and a scalogram may be generated based at least in part on the wavelet transform. One or more characteristics of the scalogram may be determined. The determined characteristics may include, for example, energy values and energy structural characteristics in a pulse band, a mains hum band, and/or a noise band. Such characteristics may be analyzed to produce signal quality values and associated signal quality trends. One or more signal quality values and signal quality trends may be used to determine if a signal quality decrease has occurred or is likely to occur. | 09-05-2013 |
20130245482 | SIGNAL PROCESSING TECHNIQUES FOR AIDING THE INTERPRETATION OF RESPIRATION SIGNALS - According to embodiments, a respiration signal may be processed to normalize respiratory feature values in order to improve and/or simplify the interpretation and subsequent analysis of the signal. Data indicative of a signal may be received at a sensor and may be used to generate a respiration signal. Signal peaks in the respiration signal may be identified and signal peak thresholds may be determined. The identified signal peaks may be adjusted based on the signal peak threshold values to normalize the respiration signal. | 09-19-2013 |
20130282296 | LOW PERFUSION SIGNAL PROCESSING SYSTEMS AND METHODS - In some embodiments, systems and methods for identifying a low perfusion condition are provided by transforming a signal using a wavelet transform to generate a scalogram. A pulse band and adjacent marker regions in the scalogram are identified. Characteristics of the marker regions are used to detect the existence of a lower perfusion condition. If such a condition is detected, an event may be triggered, such as an alert or notification. | 10-24-2013 |
20140012110 | PROCESSING AND DETECTING BASELINE CHANGES IN SIGNALS - Systems and methods for detecting the occurrence of events from a signal are provided. A signal processing system may analyze baseline changes and changes in signal characteristics to detect events from a signal. The system may also detect events by analyzing energy parameters and artifacts in a scalogram of the signal. Further, the system may detect events by analyzing both the signal and its corresponding scalogram. | 01-09-2014 |
20140058229 | SYSTEM AND METHOD FOR DETECTING FLUID RESPONSIVENESS OF A PATIENT - A system is configured to determine a fluid responsiveness index of a patient from a physiological signal. The system may include a sensor configured to be secured to an anatomical portion of the patient, and a monitor operatively connected to the sensor. The sensor is configured to sense a physiological characteristic of the patient. The monitor is configured to receive a physiological signal from the sensor. The monitor may include an index-determining module configured to determine the fluid responsiveness index through formation of a ratio of one or both of amplitude or frequency modulation of the physiological signal to baseline modulation of the physiological signal. | 02-27-2014 |
20140066732 | SYSTEM AND METHOD FOR DETERMINING CARDIAC OUTPUT - A system is configured to determine cardiac output of a patient. The system may include a first sub-system configured to detect a first physiological signal, and a second sub-system configured to detect a second physiological signal that differs from the first physiological signal. The first and second sub-systems may be separate and distinct from one another. The system may also include a cardiac output determination module that is configured to determine the cardiac output based, at least in part, on the first and second physiological signals. | 03-06-2014 |
20140066782 | SYSTEM AND METHOD FOR DETERMINING A RESTING HEART RATE OF AN INDIVIDUAL - A system to determine a resting heart rate (HR) of an individual. The system may include a monitor that is configured to be operatively connected to a sensor that obtains physiological signals from an individual. The monitor is configured to receive the physiological signals from the sensor. The monitor may include a validation module that is configured to analyze the physiological signals to identify valid heart beats from the physiological signals. The monitor may also include a rate-determining module that is configured to determine an HR signal that is based on the valid heart beats. The HR signal includes a series of data points. The monitor may also include an analysis module that is configured to analyze the HR signal and identify baseline data points from the series of data points. The analysis module is configured to calculate the resting HR based on the baseline data points. | 03-06-2014 |
20140066785 | SYSTEM AND METHOD FOR DETERMINING STROKE VOLUME OF AN INDIVIDUAL - A system for determining stroke volume of an individual. The system includes a skew-determining module that is configured to calculate a first derivative of photoplethysmogram (PPG) signals of the individual. The first derivative forms a derivative waveform. The skew-determining module is configured to determine a skew metric of the first derivative, wherein the skew metric is indicative of a morphology of at least one pulse wave detected from blood flow of the individual in the derivative waveform. The system also includes an analysis module that is configured to determine a stroke volume of the individual. The stroke volume is a function of the skew metric of the first derivative. | 03-06-2014 |
20140073962 | SYSTEM AND METHOD FOR DETERMINING STROKE VOLUME OF A PATIENT - A PPG system for determining a stroke volume of a patient includes a PPG sensor configured to be secured to an anatomical portion of the patient. The PPG sensor is configured to sense a physiological characteristic of the patient. The PPG system may include a monitor operatively connected to the PPG sensor. The monitor receives a PPG signal from the PPG sensor. The monitor includes a pulse trending module determining a slope transit time of an upslope of a primary peak of the PPG signal. The pulse trending module determines a stroke volume of the patient as a function of the slope transit time. | 03-13-2014 |
20140081098 | SENSOR SYSTEM - A sensor system is provided for determining a pulse transit time measurement of a patient. The sensor system includes a carotid sensor device configured to be positioned on a neck of the patient over a carotid artery of the patient. The carotid sensor device is configured to detect a plethysmograph waveform from the carotid artery. The sensor system includes a temporal sensor device that is operatively connected to the carotid sensor device. The temporal sensor device is configured to be positioned on the patient over a temporal artery of the patient. The temporal sensor device is configured to detect a plethysmograph waveform from the temporal artery. | 03-20-2014 |
20140175261 | METHODS AND SYSTEMS FOR DETECTING A SENSOR-OFF CONDITION USING INTERFERENCE COMPONENTS - A physiological monitoring system may use photonic signals at one or more wavelengths to determine physiological parameters. During monitoring, a physiological sensor may become improperly positioned, which may affect the physiological attenuation of the photonic signals, and accordingly a detected light signal. The detected light signal may include an ambient light component and a signal component corresponding to the one or more wavelengths of light. One or both components may exhibit an interference signal component caused by environmental light. The physiological monitoring system may analyze the interference signal components to determine a sensor-off condition. | 06-26-2014 |
20140176944 | METHODS AND SYSTEMS FOR DETERMINING A PROBE-OFF CONDITION IN A MEDICAL DEVICE - A physiological monitoring system may determine a probe-off condition. A physiological sensor may be used to emit one or more wavelengths of light. A received light signal may be processed to obtain a light signal corresponding to the emitted light and an ambient signal. The signals may be analyzed to identify similar behavior. The system may determine whether the physiological sensor is properly positioned based on the analysis. | 06-26-2014 |
20140180042 | Methods and Systems for Detecting a Sensor Off Condition Using A Reference Ambient Characteristic - A physiological monitoring system may use photonic signals at one or more wavelengths to determine physiological parameters. During monitoring, a physiological sensor may become improperly positioned, which may affect the physiological attenuation of the photonic signals, and accordingly a detected light signal. The detected light signal may include an ambient light component and a signal component corresponding to the one or more wavelengths of light. The physiological monitoring system may determine a reference characteristic based on the ambient light component, and compare the signal component with the ambient light component to determine a sensor-off condition. | 06-26-2014 |
20140180043 | METHODS AND SYSTEMS FOR DETERMINING SIGNAL QUALITY OF A PHYSIOLOGICAL SIGNAL - A physiological monitoring system may use photonic signals at one or more wavelengths to determine physiological parameters. The system may monitor a photoplethysmograph (PPG) signal, which may include a periodic component, and an aperiodic component. An attractor may be generated based on a first segment of the PPG signal and a second segment of the PPG signal shifted in time relative to the first segment by a time delay. The system may analyze points of the attractor that correspond to a curve, analyze the distribution of the attractor about a curve, or both, to determine a signal quality metric indicative of cycle to cycle variation in the PPG signal. | 06-26-2014 |
20140180044 | METHODS AND SYSTEMS FOR DETERMINING SIGNAL QUALITY OF A PHYSIOLOGICAL SIGNAL - A physiological monitoring system may use photonic signals at one or more wavelengths to determine physiological parameters. The system may receive a photoplethysmograph signal, and generated a difference signal based on the photoplethysmograph signal. The system may specify a segment of the photoplethysmograph signal and a segment of the difference signal. The system may associate each value of the segment of the photoplethysmograph signal to a corresponding value of the segment of the difference signal to generate associated value pairs. The system may compare the associated value pairs to a reference characteristic, and determine a signal quality metric based on the comparison. | 06-26-2014 |
20140207004 | SYSTEM AND METHOD FOR DETERMINING RESPIRATORY EFFORT - A system for determining respiratory effort of an individual may include a pressure signal determination module configured to determine a physiological pressure signal of the individual, a wavelet transform module configured to transform the physiological pressure signal into a scalogram using at least one wavelet transform, and a respiratory effort determination module configured to determine the respiratory effort of the individual through an analysis of scalogram. | 07-24-2014 |
20140213862 | WAVELET-BASED SYSTEM AND METHOD FOR ANALYZING A PHYSIOLOGICAL SIGNAL - Certain embodiments of the present disclosure provide a system and method for analyzing a physiological signal detected from an individual. The system may include a physiological signal detection module configured to detect the physiological signal of the individual, a wavelet formation module configured to form a wavelet based on the physiological signal, and a wavelet transform module configured to generate a scalogram by transforming the physiological signal with the wavelet based on the physiological signal. | 07-31-2014 |
20140243633 | METHODS AND SYSTEMS FOR DETERMINING A PROBE-OFF CONDITION IN A MEDICAL DEVICE - A physiological monitoring system may determine a probe-off condition. A physiological sensor may receive a light signal including one or more wavelengths of light. The received light signal may be processed to obtain a light signal corresponding to an ambient light signal and a light signal corresponding to an emitted light signal and the ambient light signal. The signals may be analyzed to identify an inverse effect. The system may determine whether the physiological sensor is properly positioned based on the identification of an inverse effect. | 08-28-2014 |
20140244205 | SYSTEMS AND METHODS FOR GENERATING AN ARTIFICIAL PHOTOPLETHYSMOGRAPH SIGNAL - A test unit may generate a pulse signal based on a pulsatile profile and a frequency modulation component of a respiratory profile. A respiration modulated signal may be generated from the pulse signal, an amplitude modulation component, and a baseline modulation component. A patient modulated signal may be generated based on the respiration modulated signal and a patient profile. The artificial PPG signal may be generated based on the patient modulated signal and an artifact profile. The artificial PPG signal may be output to an electronic device. | 08-28-2014 |
20140257061 | SYSTEMS AND METHODS FOR DETERMINING OXYGEN SATURATION - According to embodiments, techniques for using continuous wavelet transforms and spectral transforms to determine oxygen saturation from photoplethysmographic (PPG) signals are disclosed. According to embodiments, a first and a second PPG signals may be received. A spectral transform of the first and the second PPG signals may be performed to produce a first and a second spectral transformed signals. A frequency region associated with a pulse rate of the PPG signals may be identified from the first and the second spectral transformed signals. According to embodiments, a continuous wavelet transform of the first and the second PPG signals may be performed at a scale corresponding to the identified frequency region to produce a first and a second wavelet transformed signals. The oxygen saturation may be determined based at least in part upon the wavelet transformed signals. | 09-11-2014 |
20140275879 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION BASED ON INDEPENDENT COMPONENT ANALYSIS - A patient monitoring system may receive a physiological signal such as a photoplethysmograph (PPG) signal. A plurality of respiration morphology signals may be determined from the PPG signal. Independent component analysis may be performed on the respiration morphology signals, resulting in a plurality of independent components. An independent component corresponding to a respiration source signal may be selected from the plurality of independent components. Respiration information such as respiration rate may be determined based at least in part on the selected independent component. | 09-18-2014 |
20140275882 | Methods and Systems for Determining a Probe-Off Condition in a Medical Device - A physiological monitoring system may use one or more characteristics of an ambient signal to determine a probe-off condition. A physiological sensor may be used to emit one or more wavelengths of light. A light signal may be received that includes an ambient light component and one or more components corresponding to the emitted light. One or more characteristics (e.g., baseline characteristics) of the ambient light component may be determined and compared to one or more thresholds. The system may determine whether the physiological sensor is properly positioned based on the comparison. | 09-18-2014 |
20140275938 | SYSTEM AND METHOD FOR DETERMINING REPETITIVE AIRFLOW REDUCTIONS - Certain embodiments of the present disclosure provide a system and method for determining a repetitive airflow reduction of an individual. The system may include a photoplethysmogram (PPG) detection module configured to detect a PPG signal of a patient. The PPG signal may include a pulsatile AC component superimposed on a DC baseline. The system may also include a PPG baseline analysis module configured to analyze the DC baseline of the PPG signal to detect one or more threshold crossings with respect to an acceptable threshold correlated to normal breathing. The system may also include a repetitive airflow reduction determination module configured to determine an occurrence of the repetitive airflow reduction through an analysis of the one or more threshold crossings. | 09-18-2014 |
20140278388 | SYSTEMS AND METHODS FOR IDENTIFYING PATIENT DISTRESS BASED ON A SOUND SIGNAL - A sound signal from a patient may include information that may be used to determine multiple patient parameters. A patient monitor may determine respiration information such as respiration rate from the sound signal, for example based on modulations of the sound signal due to patient breathing. The patient monitor may also determine indications of patient distress based on a trained classifier, speech commands, or sound patterns. | 09-18-2014 |
20140316286 | SYSTEM AND METHOD FOR DETERMINING RESPIRATORY PARAMETERS FROM BLOOD FLOW SIGNALS - A system for determining one or more respiratory parameters of an individual may include a blood flow detection device configured to detect a blood flow signal of the individual, a blood flow determination module configured to form a blood flow waveform based on the blood flow signal, and a respiratory parameter analysis module configured to analyze the blood flow waveform and determine the respiratory parameter(s) from an analysis of the blood flow waveform. | 10-23-2014 |
20140316287 | System and method for displaying fluid responsivenss predictors - Embodiments provide systems and methods for displaying a fluid responsiveness predictor (FRP) based on an analysis a physiological signal detected by a physiological sensor applied to a patient. A method may include detecting the signal of the patient with the physiological sensor, determining an FRP with a FRP determination module, wherein the determining operation comprises analyzing at least one characteristic of the physiological signal over time to determine the FRP, receiving a report request to report the FRP at a requested time through a user interface, generating a reported FRP in relation to the requested time using the FRP determination module, and displaying the reported FRP on a display. The displaying operation may include displaying the FRP using at least one graphic representation. | 10-23-2014 |
20140323846 | SYSTEM AND METHOD FOR DETERMINING HEMODYNAMIC STATUS THROUGH A BLOOD PRESSURE RELATED INDEX - A system for determining a hemodynamic status of an individual may include a photoplethysmography (PPG) sub-system configured to detect a PPG signal and a response triggering module configured to analyze the PPG signal and output one or more response triggers based on a changing feature of the PPG signal within a time window. Each of the one or more response triggers may relate to an instruction to initiate detection of at least one physiological characteristic of the individual. A blood pressure (BP) variability index determination module is configured to determine a BP variability index related to a hemodynamic status of the individual based on a frequency or pattern of the one or more response triggers. | 10-30-2014 |