Patent application number | Description | Published |
20090323049 | Systems And Methods For A Wavelet Transform Viewer - Techniques for the display of a signal with a wavelet transform of that signal in a wavelet transform viewer are disclosed, according to embodiments. According to embodiments, the wavelet transform viewer can display a plot of physiological signals such as a photoplethysmograph (PPG) signal. A portion of the plot of the signal can be selected. A wavelet transform the selected portion of the signal can be calculated and a wavelet plot of the tranformed signal can be displayed simultaneously with that signal. A plot of the selected portion of the signal can also be simultaneously displayed with both the plot of the signal and the wavelet plot. | 12-31-2009 |
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 |
20090324034 | SYSTEMS AND METHODS FOR RIDGE SELECTION IN SCALOGRAMS OF SIGNALS - According to embodiments, systems, devices, and methods for ridge selection in scalograms are disclosed. Ridges or ridge components are features within a scalogram which may be computed from a signal such as a physiological (e.g., photoplethysmographic) signal. Ridges may be identified from one or more scalograms of the signal. Parameters characterizing these ridges may be determined. Based at least in part on these parameters, a ridge density distribution function is determined. A ridge is selected from analyzing this ridge density distribution function. In some embodiments, the selected ridge is used to determine a physiological parameter such as respiration rate. | 12-31-2009 |
20090326351 | Signal Processing Mirroring Technique - Embodiments may include systems and methods capable of processing an original signal by selecting and mirroring portions of the signal to create a new signal for further analysis. In an embodiment, the signal may be a photoplethysmograph (PPG) signal and the new signal may be further analyzed using continuous wavelet transforms. Any suitable number of reconstructed new signals may be created from the original signal and scalograms may be derived at least in part from the new signals. Ridges may be extracted from the scalograms of the new signals and secondary scalograms may be further derived from the ridges. A sum along amplitudes technique may be applied to a selected scalogram and may be plotted as a function of the scale of the scalogram. Desired information, such as respiration information within the original signal, may be identified from the plot. | 12-31-2009 |
20090326388 | Systems And Methods For Processing Signals With Repetitive Features - The present disclosure relates to systems and methods for detecting features of a signal. According to embodiments, by transposing segments of a signal, such as segments representing pulses in a PPG signal, such that they are stacked next to each other, various characteristics about the signal may be discerned such as information about repetitive features of the signal. According to an embodiment, from a PPG signal respiration information may be determined about individual breaths, blood pressure changes may be determined, and information about other physiological parameters affecting the PPG signal may be determined. | 12-31-2009 |
20090326402 | SYSTEMS AND METHODS FOR DETERMINING EFFORT - According to embodiments, methods and systems for determining effort is disclosed. Effort may relate to a measure of strength of at least one repetitive feature in a signal. Effort may also relate to physical effort or work of a process (e.g., respiratory effort) that may affect the signal (e.g., a PPG signal). Effort may be determined through feature analysis of a transformed signal that has been transformed via a continuous wavelet transform. For example, respiratory effort may be determined using a scalogram generated based at least in part on a wavelet transform of a physiological signal and analyzing features of the scalogram. | 12-31-2009 |
20090326831 | Concatenated Scalograms - Embodiments may include systems and methods capable of processing an original signal by selecting and mirroring portions of the signal to create new signals. Any suitable number of new signals may be created from the original signal and scalograms may be derived at least in part from the new signals. Regions of the scalograms may be selected based on a characteristic of the original signal. The selected regions may be concatenated, and a sum along amplitudes across time may be applied to the concatenated regions. Desired information, such as respiration information within the original signal, may be determined from the sum along amplitudes across time. | 12-31-2009 |
20090326867 | SIGNAL PROCESSING SYSTEMS AND METHODS FOR DETERMINING SLOPES OF ELECTRONIC SIGNALS - The present disclosure relates to signal processing and, more particularly, relates to determining the slope of a signal. In embodiments, first slopes between a first point in the signal and other points in the signal may be determined. Second slopes between a second point in the signal and other points in the signal may also be determined. The first and second slopes may be used to generate a histogram, and a desired slope may be selected from the preferred value of the histogram. 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 at least in part from surface signals related to two transform-surfaces. Each transform-surface 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 |
20090326871 | SYSTEMS AND METHODS FOR ARTIFACT DETECTION IN SIGNALS - According to embodiments, a method and system for artifact detection in signals is disclosed. The artifacts may take the form of movement artifacts in physiological (e.g., pulse oximetry) signals. Artifacts in the wavelet space of the physiological signal may be removed, replaced, ignored, filtered, or otherwise modified by determining the energy within a predefined moving area of the wavelet scalogram, comparing the determined energy within the predefined moving area of the wavelet scalogram to a threshold value, and masking at least one area of artifact in the wavelet scalogram based, at least in part, on the comparison. From the enhanced signal, physiological parameters, for example, respiration, respiratory effort, pulse, and oxygen saturation, may be more reliably and accurately derived or computed. | 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 |
20100014761 | 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. | 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 |
20100016690 | 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 oxygen saturation may be determined from wavelet transformed PPG signals and a second oxygen saturation may be determined from spectral transformed PPG signals. An optimal oxygen saturation may be determined by selecting one of the first and the second oxygen saturation or by combining the first and the second oxygen saturation. According to embodiments, a spectral transform of PPG signals may be performed to identify a frequency region associated with a pulse rate of the PPG signal. A continuous wavelet transform of the PPG signals at a scale corresponding to the identified frequency region may be performed to determine oxygen saturation from the wavelet transformed signal. | 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 |
20100081943 | Detecting Sleep Events Using Localized Blood Pressure Changes - Techniques for detecting sleep events are disclosed. In some embodiments, a continuous non-invasive blood pressure (“CNIBP”) monitoring system may be used to obtain blood pressure values from a subject during a sleep study. Changes in the blood pressure over time may be determined and analyzed in order to identify a sleep event. The localized blood pressure changes may be interpreted in isolation or in combination with other signals collected from the subject. | 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 |
20100087714 | REDUCING CROSS-TALK IN A MEASUREMENT SYSTEM - According to embodiments, techniques for determining one or more physiological characteristics in a measurement system which may include cross-talk are disclosed. A sensor or probe may be used to generate two or more a plethysmograph or photoplethysmograph (PPG) signals from a patient. The obtained signals may include an infrared signal and a red signal, and may be subject to an additional measurement noise. The obtained signal may be combined to form a detected signal. The detected signal may be filtered to partially or fully remove noise. The filtered detected signal may be demodulated to separate the red signal and the infrared signal. The recovered red and infrared signals may be processed by additional filters to partially or fully remove cross-talk. The processed red and infrared signals may then be used to determine physiological characteristics of a patient such as a pulse rate, a respiration rate, and a blood oxygen saturation level using the wavelet transform and/or scalogram of at least one of the processed red and infrared signals. The partial or full removal of cross-talk from the red signal and infrared signal may result in a more reliable determination of physiological characteristics than would be possible in a system in which cross-talk was not removed. | 04-08-2010 |
20100087720 | Extraction Of Physiological Measurements From A Photoplethysmograph (PPG) Signal - The present disclosure relates to signal processing and, more particularly, to determining the value of a physiological parameter, such as the blood oxygen saturation (SpO | 04-08-2010 |
20100228102 | SYSTEMS AND METHODS FOR MONITORING HEART RATE AND BLOOD PRESSURE CORRELATION - Systems and methods are provided for monitoring a correlation between heart rate and blood pressure in a patient. When a characteristic of the correlation exceeds a threshold, a patient status indicator signal is sent to a monitoring device In some embodiments, the patient status indicator signal indicates a particular medical condition or alerts a care provider to a change in status. In some embodiments, the heart rate signal is used to improve a blood pressure estimate generated by a different signal. In some embodiments, the heart rate, blood pressure and correlation signals are used in a predictive mathematical model to estimate patient status or outcome. | 09-09-2010 |
20100249543 | SYSTEMS AND METHODS FOR MONITORING PAIN MANAGEMENT - The present disclosure relates to systems and methods for monitoring pain management using measurements of physiological parameters based on a PPG signal. A reference physiological parameter may be compared against a later measurement to identify a change in condition that may indicate a pain management problem. | 09-30-2010 |
20100249544 | SYSTEMS AND METHODS FOR MONITORING PAIN MANAGEMENT - The present disclosure relates to systems and methods for monitoring pain management using measurements of physiological parameters based on a PPG signal. A reference physiological parameter may be compared against a later measurement to identify a change in condition that may indicate a pain management problem. | 09-30-2010 |
20100249555 | SYSTEMS AND METHODS FOR MONITORING PAIN MANAGEMENT - The present disclosure relates to systems and methods for monitoring pain management using measurements of physiological parameters based on a PPG signal. A reference physiological parameter may be compared against a later measurement to identify a change in condition that may indicate a pain management problem. | 09-30-2010 |
20100249556 | SYSTEMS AND METHODS FOR MONITORING PAIN MANAGEMENT - The present disclosure relates to systems and methods for monitoring pain management using measurements of physiological parameters based on a PPG signal. A reference physiological parameter may be compared against a later measurement to identify a change in condition that may indicate a pain management problem. | 09-30-2010 |
20100286494 | USING COLORED PROBES IN PATIENT MONITORING - The present disclosure provides a sensor with color-coded indications that various patient physiological parameters are being monitored, such as blood oxygen saturation, blood pressure, respiration rate, and respiration effort. The sensor may sense a physical characteristic used to monitor the physiological parameter, and a visible light emitter emits visible light of a first color that is color-coded to the physiological parameter, but is not used to sense the physical characteristic. The visible light emitter may emit visibly flashing light in response to the sensor sensing a threshold value of the physical characteristic. The sensor may include a second light emitter that may sense the physical characteristic, and may emit light of a second color that is color-coded to a first or second physiological parameter. In some embodiments, the first and second colors may visibly mix. The first and second visible light emitters may emit light independently, including visibly flashing light. | 11-11-2010 |
20100298676 | Estimating Transform Values Using Signal Estimates - According to embodiments, estimated values for a signal transform may be generated using estimated values for the signal. Signal parameters may then be determined based on the estimated signal transform. A first portion of a signal may be obtained. A second portion of the signal may be estimated. The second portion of the signal may correspond to a portion of the that is unknown, that is not yet available and/or that is obscured by noise and/or artifacts. A transform (e.g., a continuous wavelet transform) of both of the signal portions may be performed. One or more parameters corresponding to the signal may then be determined from transformed signal. | 11-25-2010 |
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 |
20100312075 | 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. | 12-09-2010 |
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 |
20100331715 | SYSTEMS AND METHODS FOR DETECTING EFFORT EVENTS - A method and system for detecting effort events is disclosed. Effort may be determined through feature analysis of the signal as transformed by a continuous wavelet transform, which may be compared against a reference effort measure to trigger an effort event flag that signals the onset and/or severity of an effort event. For example, a respiratory effort measure may be determined based at least in part on a wavelet transform of a photoplethysmograph (PP G) signal and features of the transformed signal. A respiratory reference effort measure may be based at least in part on past values of the respiratory effort measure, and a threshold test may be used to trigger an effort event flag, which may indicate a marked change in respiratory effort exerted by a patient. | 12-30-2010 |
20100331724 | DETERMINING A CHARACTERISTIC BLOOD PRESSURE - The present disclosure relates to monitoring a characteristic physiological parameter of a patient during a suitable time period that either precedes or follows a triggering event, such as a clinician/patient interaction, that 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, tracking the physiological parameter 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 physiological parameter. The patient signal used to derive a patient's physiological parameter may be of an oscillatory nature or may include oscillatory features that may be analyzed to derive a characteristic respiration rate. | 12-30-2010 |
20100332173 | SYSTEMS AND METHODS FOR ASSESSING MEASUREMENTS IN PHYSIOLOGICAL MONITORING DEVICES - Methods and systems are provided for deriving and analyzing shape metrics, including skewness metrics, from physiological signals and their derivatives to determine measurement quality, patient status and operating conditions of a physiological measurement device. Such determinations may be used for any number of functions, including indicating to a patient or care provider that the measurement quality is low or unacceptable, alerting a patient or care provider to a change in patient status, triggering or delaying a recalibration of a monitoring device, and adjusting the operating parameters of a monitoring system. | 12-30-2010 |
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 |
20110004081 | METHODS AND APPARATUS FOR DETERMINING BREATHING EFFORT CHARACTERISTIC MEASURES - One or more respiratory characteristics of a patient are measured by coupling patient monitor apparatus (e.g., a photoplethysmograph (“PPG”)) to the patient in order to produce a patient monitor signal that includes signal indicia indicative of effort the patient is exerting to breathe. A breathing or respiratory effort signal for the patient is extracted from the patient monitor signal. A respiratory characteristic signal is extracted (at least in part) from the effort signal. This may be done, for example, on the basis of an amplitude feature of the effort signal and a relative time of occurrence of that amplitude feature. Alternatively, the respiratory characteristic signal may be based on a relationship between two amplitude features of the effort signal, with or without regard for specifics of the times of occurrence of those amplitude features. A breath air flow meter may also be coupled to the patient, if desired, in order to produce a flow signal. One or more of the respiratory characteristic measures may also be partly based on the flow signal. | 01-06-2011 |
20110021892 | SYSTEMS AND METHODS FOR RESPIRATION MONITORING - According to embodiments, techniques for determining respiratory parameters are disclosed. More suitable probe locations for determining respiratory parameters, such as respiration rate and respiratory effort, may be identified. The most suitable probe location may be selected for probe placement. A scalogram may be generated from the detected signal at the more suitable location, resulting in an enhanced breathing band for determining respiratory parameters. Flexible probes that allow for a patient's natural movement due to respiration may also be used to enhance the breathing components of the detected signal. From the enhanced signal, more accurate and reliable respiratory parameters may be determined. | 01-27-2011 |
20110021941 | SYSTEMS AND METHODS FOR RESPIRATION MONITORING - According to embodiments, techniques for determining respiratory parameters are disclosed. More suitable probe locations for determining respiratory parameters, such as respiration rate and respiratory effort, may be identified. The most suitable probe location may be selected for probe placement. A scalogram may be generated from the detected signal at the more suitable location, resulting in an enhanced breathing band for determining respiratory parameters. Flexible probes that allow for a patient's natural movement due to respiration may also be used to enhance the breathing components of the detected signal. From the enhanced signal, more accurate and reliable respiratory parameters may be determined. | 01-27-2011 |
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 |
20110028802 | METHODS AND APPARATUS FOR PRODUCING AND USING LIGHTLY FILTERED PHOTOPLETHYSMOGRAPH SIGNALS - One or more physiological conditions of a patient can be observed by obtaining a photoplethysmograph (“PPG”) signal from the patient and by only lightly filtering that signal. The light filtering of the PPG may be such as to only remove (for example) high frequency noise from that signal, while leaving in the signal most or all frequency components that are due to physiological events in the patient. In this way, such physiological events can be observed via a visual display of the lightly filtered PPG signal and/or via other signal processing of the lightly filtered PPG signal to automatically extract certain physiological parameters or characteristics from that signal. | 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 |
20110028854 | SYSTEMS AND METHODS FOR NON-INVASIVE DETERMINATION OF BLOOD PRESSURE - Methods and systems for determining blood pressure from a pressure signal are disclosed. A patient's blood pressure may be determined by analyzing features of a wavelet transformation of a pressure signal obtained during an occlusion procedure. Ridges in a scalogram of the transformed signal may be identified and used to determine an envelope of a pressure oscillation signal, to which oscillometric blood pressure determination techniques may be applied. | 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 |
20110074409 | Systems And Methods For Gating An Imaging Device - A method and system for automatically gating an imaging device is disclosed. Physiological process information of a patient may be derived from a plethysmographic signal, for example, by analyzing the plethysmographic signal transformed by a continuous wavelet transform. Other techniques for deriving physiological process information of a patient include, for example, analyzing a scalogram derived from the continuous wavelet transform. The physiological process information may be used to automatically gate imaging data acquired from an imaging device in order to synchronize the imaging data with the physiological process information. | 03-31-2011 |
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 |
20110077486 | SYSTEMS AND METHODS FOR NORMALIZING A PLETHYSMOGRAPH SIGNAL FOR IMPROVED FEATURE ANALYSIS - The present disclosure relates to systems and methods for analyzing and normalizing signals, such as PPG signals, for use in patent monitoring. The PPG signal may be detected using a continuous non-invasive blood pressure monitoring system and the normalized signals may be used to determine whether a recalibration of the system should be performed. | 03-31-2011 |
20110077531 | SYSTEMS AND METHODS FOR HIGH-PASS FILTERING A PHOTOPLETHYSMOGRAPH SIGNAL - According to embodiments, systems and methods for high-pass filtering a plethysmograph or photoplethysmograph (PPG) signal are disclosed. A sensor or probe may be used to obtain a plethysmograph or PPG signal from a subject. The sensor may be placed at any suitable location on the body, e.g., the forehead, finger, or toe. The PPG signal generated by the sensor may be high-pass filtered to disambiguate certain features of the PPG signal, including one or more characteristic points. The cut-off frequency for the high-pass filter may be greater than 0.75 Hz and less than 15 Hz. The cut-off frequency for the high-pass filter may be selected to be greater than the subject's computed pulse rate. These characteristic points on the filtered PPG signal may be used to compute non-invasive blood pressure measurements continuously or on a periodic basis. For example, the time difference between two or more characteristic points in a high-pass filtered version of the generated PPG signal may be computed. The time difference may be used to compute non-invasive blood pressure measurements continuously or on a periodic basis. | 03-31-2011 |
20110112379 | SYSTEMS AND METHODS FOR PROVIDING SENSOR ARRAYS FOR DETECTING PHYSIOLOGICAL CHARACTERISTICS - Systems and methods for determining physiological parameters of a subject using a sensor array. In an embodiment, a sensor array may contain sensor elements for determining multiple physiological parameters. A combination of sensor elements and the physiological parameters determined may be selected based on signals obtained from the sensor elements of the sensor array. A sensor array may be connected to a monitoring device that may select an optimal sensor element or combination of sensor elements and one or more physiological parameters to be determined. The monitoring device may then determine physiological parameters using the selected combination of sensor elements and display information associated with the parameters on a monitor for use, for example, in monitoring a medical patient. | 05-12-2011 |
20110112382 | SYSTEMS AND METHODS FOR COMBINED PHYSIOLOGICAL SENSORS - Systems and methods are provided for monitoring the physiological state of a subject. One or more physiological parameters of a subject may be determined from a photoplethysmograph (PPG) signal or signals obtained using at least one PPG sensor. In some embodiments, an electrical physiological signal (EPS) sensor may be located in or near a PPG sensor. A sensor configuration including both PPG sensors and EPS sensors may be advantageously used to detect a PPG signal or signals in combination with one or more EPS signal or signals. To reduce potential interference between an EPS sensor and a PPG sensor, fiber-optic input and output lines may be used to transmit optical signals from light generating circuitry and light detecting circuitry. In some embodiments, the generating and detecting circuitry may be located remotely from one another and may further be located remotely from the EPS sensor, PPG sensor, or both. | 05-12-2011 |
20110112387 | SIMULTANEOUS MEASUREMENT OF PULSE AND REGIONAL BLOOD OXYGEN SATURATION - Methods and systems are provided that allow for the simultaneous calculation of pulse and regional blood oxygen saturation. An oximeter system that includes a sensor with a plurality of emitters and detectors may be used to calculate a pulse and/or regional blood oxygen saturation. A plurality of light signals may be emitted from light emitters. A first light signal may be received at a first light detector and a second light signal may be received at a second light detector. A pulse and/or regional blood oxygen saturation value may be calculated based on the received first and/or second light signals. The pulse and regional blood oxygen saturation values may be calculated substantially simultaneously. The calculated pulse and regional blood oxygen saturation values as well as other blood oxygen saturation values may be displayed simultaneously in a preconfigured portion of a display. | 05-12-2011 |
20110190600 | COMBINED PHYSIOLOGICAL SENSOR SYSTEMS AND METHODS - A combined physiological sensor and methods for detecting one or more physiological characteristics of a subject are provided. The combined sensor (e.g., a forehead sensor) may be used to detect and/or calculate at least one of a pulse blood oxygen saturation level, a regional blood oxygen saturation level, a respiration rate, blood pressure, an electrical physiological signal (EPS), a pulse transit time (PTT), body temperature associated with the subject, a depth of consciousness (DOC) measurement, any other suitable physiological parameter, and any suitable combination thereof. The combined sensor may include a variety of individual sensors, such as electrodes, optical detectors, optical emitters, temperature sensors, and/or other suitable sensors. The sensors may be advantageously positioned in accordance with a number of different geometries. The combined sensor may also be coupled to a monitoring device, which may receive and/or process one or more output signals from the individual sensors to display information about the medical condition of the subject. In addition, several techniques may be employed to prevent or limit interference between the individual sensors and their associated input and/or output signals. | 08-04-2011 |
20110245690 | SYSTEMS AND METHODS FOR MEASURING ELECTROMECHANICAL DELAY OF THE HEART - Systems and methods are disclosed herein for measuring the electromechanical delay of the heart of a patient. An electrocardiogram (EKG) signal may be used to detect heart electrical activity. Photoplethysmograph (PPG) signals may be used to detect heart mechanical activity. The electromechanical delay may be calculated based at least in part on the timing of an EKG signal and at least two PPG signals. | 10-06-2011 |
20110270048 | SYSTEMS AND METHODS FOR PPG SENSORS INCORPORATING EKG SENSORS - Techniques and structures are disclosed for using photoplethysmograph (PPG) and electrocardiographic (EKG)-based readings of a subject to determine one or more physiological characteristics of the subject. In an arrangement, a combined PPG-EKG sensor unit may be used to detect both PPG and EKG signals of the subject. The sensor unit may include a PPG sensor, an EKG sensor, and a support structure for connecting or fastening the sensor unit to the subject. The detected readings may be provided to an electronic monitor. In an arrangement, a PPG-EKG monitoring system, including the electronic monitor, may be used to determine the physiological parameters of the subject. The monitoring system may first determine an auxiliary parameter based at least in part on the EKG signal, and then compute the one or more physiological characteristics of the subject based at least in part on both the PPG signal and the auxiliary parameter. | 11-03-2011 |
20110270114 | METHODS AND APPARATUS FOR CALIBRATING RESPIRATORY EFFORT FROM PHOTOPLETHYSMOGRAPH SIGNALS - Breathing effort of a patient, as determined (for example) from a photoplethysmograph (“PPG”) signal from the patient, can be calibrated in relation to air pressure in the patient's respiratory system. This calibration can be done by subjecting the patient to varying amounts of breathing resistance; and for each such amount, concurrently measuring (1) air pressure in the respiratory system (e.g., in the oral/nasal cavity) and (2) breathing effort (from the PPG signal). Use can be made of this calibration, e.g., during a sleep study of the patient. During such a study, breathing effort, again determined from the PPG signal and occurring, for example, during an apneic event of the patient, can be used to infer air pressure in the respiratory system by using the above calibration. | 11-03-2011 |
20110270579 | SYSTEMS AND METHODS FOR SIGNAL MONITORING USING LISSAJOUS FIGURES - Methods and systems are provided for generating Lissajous figures based on monitored signals and identifying features of Lissajous figures. Features may include similarity metrics, shape change metrics and noise metrics, and may be used to determine information about the monitored signal. Features may also be used in monitoring operations, such as measurement quality assessment and recalibration. | 11-03-2011 |
20110306858 | Systems And Methods For Wavelet Transform Using Mean-Adjusted Wavelets - Methods and systems are disclosed for transforming a signal using a continuous wavelet transform based at least in part on a truncated, mean-adjusted wavelet. A wavelet may be truncated to a finite support to generate a truncated wavelet. The real part of the truncated wavelet may be forced to have a zero mean to generate a truncated, mean-adjusted wavelet. The signal may be transformed using a continuous wavelet transform based at least in part on the truncated mean-adjusted wavelet. Information may be derived about the signal from the transformed signal. | 12-15-2011 |
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 |
20120029320 | SYSTEMS AND METHODS FOR PROCESSING MULTIPLE PHYSIOLOGICAL SIGNALS - Systems and methods are provided for patient monitors which apply different sets of signal processing operations to signals to identify multiple fiducials in physiological signals. PPG signals measured at two sensor sites may be processed with a first set of processing operations and analyzed to identify fiducials that allow the calculation of a diastolic DPTT. These PPG signals may then be processed with a different set of processing operations and the results analyzed to identify fiducials that allow the calculation of a systolic DPTT. | 02-02-2012 |
20120029361 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATORY EFFORT - Systems and methods for calculating a measure of respiratory effort of a subject are provided. The measure of respiratory effort may be calculated based on a differential pulse transit time (DPTT) calculated for received photoplethysmograph signals. The systems and methods may allow for the calculation of respiratory effort in absolute units, and without the need for calibrations from a device that measures blood pressure (e.g., a non-invasive blood pressure cuff). | 02-02-2012 |
20120116235 | SYSTEMS AND METHODS FOR PRODUCING AUDIBLE INDICATORS THAT ARE REPRESENTATIVE OF MEASURED BLOOD PRESSURE - Systems and methods are disclosed for producing audible indicators that are based on a subject's measured blood pressure. Audible properties of the indicators are processed to represent blood pressure. For example, the duration or volume of the audible indicators may be varied based on the values of the subject's blood pressure. The audible indicators may further be varied based on the subject's blood pressure's deviation from a normal blood pressure and/or previously calculated blood pressure. For example, the audible indicators may be indicative of changes in the subject's blood pressure over time. The audible indicators representing blood pressure may be synchronized with other audible indicators that represent other physiological parameters of the subject, such as, the subject's heart rate. | 05-10-2012 |
20120123689 | 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. | 05-17-2012 |
20120136261 | Systems and methods for calibrating physiological signals with multiple techniques - Systems and methods are disclosed herein for calibrating the calculation of physiological parameters. Two or more calibration techniques may be used to determine a relationship between physiological measurements and a desired physiological parameter, such as a relationship between differential pulse transit time (DPTT) and blood pressure. Different calibration techniques may be used in a serial fashion, one after the other, or in a parallel fashion, with different weights accorded to each calibration technique. When physiological or other changes occur, the calibration data may be stored for later use and new calibration data may be generated. | 05-31-2012 |
20120136605 | METHODS AND SYSTEMS FOR RECALIBRATING A BLOOD PRESSURE MONITOR WITH MEMORY - Systems and methods are provided for storing and recalling metrics associated with physiological signals. It may be determined that the value of a monitored physiological metric corresponds to a stored value. In such cases, a patient monitor may determine that a calibration is not desired. In some cases, a patient monitor may recall calibration parameters associated with the stored value if it determined that the stored value corresponds to the monitored metric value. | 05-31-2012 |
20120143012 | SYSTEMS AND METHODS FOR PHYSIOLOGICAL EVENT MARKING - Systems and methods are provided for storing event markers. The value of a monitored physiological metric may be monitored and compared to a reference value. A patient monitoring system may compute a difference between a monitored metric and a reference value, and compare the difference to a threshold value to determine whether a physiological event has occurred. Based on the determination, a patient monitoring system may store an event marker, trigger a response, update a metric value, or perform any other suitable function. | 06-07-2012 |
20120143067 | SYSTEMS AND METHODS FOR DETERMINING WHEN TO MEASURE A PHYSIOLOGICAL PARAMETER - Systems and methods are provided for determining when to update a blood pressure measurement. The value of a physiological metric may be monitored and compared to a reference value. A patient monitoring system may compute a difference between a monitored metric and a reference value, and compare the difference to a threshold value to determine whether to update a blood pressure measurement. The threshold value may be constant or variable, and may depend on the monitored metric. | 06-07-2012 |
20120203087 | SYSTEMS AND METHODS FOR MONITORING DEPTH OF CONSCIOUSNESS - During patient monitoring, a depth of consciousness (DOC) measure, such as a bispectral index, may be used in conjunction with additional information obtained from an awareness metric derived from one or more physiological signals, such as a photoplethysmograph signal. In an embodiment, a DOC measure may be combined with information from an awareness metric to produce a combined DOC measure. In an embodiment, information from an awareness metric derived from one or more physiological signals may be used to provide an indication of confidence in a DOC measure. In an embodiment, a DOC measure may be used to provide an indication of confidence in a depth of consciousness assessment based on an awareness metric. In an embodiment, one or the other of a DOC measure and an awareness metric may be used to provide an indication of a patient's depth of consciousness (e.g., by one “overriding” the other). | 08-09-2012 |
20120253141 | METHODS AND SYSTEMS FOR PASSIVE PHOTOPLETHYSMOGRAPH SENSING - Systems and methods are provided for passive photoplethysmograph sensing. A patient monitoring system may provide active sensing, passive sensing, or both. In some cases, a patient monitor may determine whether to provide passive or active sensing. Passive photoplethysmograph sensing may be used to determine physiological information such as pulse rate, respiration rate, or other information. Passive photoplethysmograph sensing may allow for reduced power consumption relative to active sensing. | 10-04-2012 |
20120259235 | Systems and Methods for Monitoring Heart Rate and Blood Pressure Correlation - Systems and methods are provided for monitoring a correlation between heart rate and blood pressure in a patient. When a characteristic of the correlation exceeds a threshold, a patient status indicator signal is sent to a monitoring device. In some embodiments, the patient status indicator signal indicates a particular medical condition or alerts a care provider to a change in status. In some embodiments, the heart rate signal is used to improve a blood pressure estimate generated by a different signal. In some embodiments, the heart rate, blood pressure and correlation signals are used in a predictive mathematical model to estimate patient status or outcome. | 10-11-2012 |
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 |
20130011032 | Systems and Methods for Ridge Selection in Scalograms of Signals - According to embodiments, systems, devices, and methods for ridge selection in scalograms are disclosed. Ridges or ridge components are features within a scalogram which may be computed from a signal such as a physiological (e.g., photoplethysmographic) signal. Ridges may be identified from one or more scalograms of the signal. Parameters characterizing these ridges may be determined Based at least in part on these parameters, a ridge density distribution function is determined A ridge is selected from analyzing this ridge density distribution function. In some embodiments, the selected ridge is used to determine a physiological parameter such as respiration rate. | 01-10-2013 |
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 |
20130296674 | SYSTEMS AND METHODS FOR NORMALIZING A PLETHYSMOGRAPH SIGNAL FOR IMPROVED FEATURE ANALYSIS - The present disclosure relates to systems and methods for analyzing and normalizing signals, such as PPG signals, for use in patent monitoring. The PPG signal may be detected using a continuous non-invasive blood pressure monitoring system and the normalized signals may be used to determine whether a recalibration of the system should be performed. | 11-07-2013 |
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 |
20140016840 | SYSTEMS AND METHODS FOR RIDGE SELECTION IN SCALOGRAMS OF SIGNALS - According to embodiments, systems, devices, and methods for ridge selection in scalograms are disclosed. Ridges or ridge components are features within a scalogram which may be computed from a signal such as a physiological (e.g., photoplethysmographic) signal. Ridges may be identified from one or more scalograms of the signal. Parameters characterizing these ridges may be determined. Based at least in part on these parameters, a ridge density distribution function is determined. A ridge is selected from analyzing this ridge density distribution function. In some embodiments, the selected ridge is used to determine a physiological parameter such as respiration rate. | 01-16-2014 |
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 |
20140073886 | SIMULTANEOUS MEASUREMENT OF PULSE AND REGIONAL BLOOD OXYGEN SATURATION - Methods and systems are provided that allow for the simultaneous calculation of pulse and regional blood oxygen saturation. An oximeter system that includes a sensor with a plurality of emitters and detectors may be used to calculate a pulse and/or regional blood oxygen saturation. A plurality of light signals may be emitted from light emitters. A first light signal may be received at a first light detector and a second light signal may be received at a second light detector. A pulse and/or regional blood oxygen saturation value may be calculated based on the received first and/or second light signals. The pulse and regional blood oxygen saturation values may be calculated substantially simultaneously. The calculated pulse and regional blood oxygen saturation values as well as other blood oxygen saturation values may be displayed simultaneously in a preconfigured portion of a display. | 03-13-2014 |
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 |
20140094672 | 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. | 04-03-2014 |
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 |
20140275877 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION BASED ON PRINCIPAL 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. Principal component analysis may be performed on the respiration morphology signals, resulting in one or more principal components. Respiration information such as respiration rate may be determined at least in part from a principal component that corresponds to a respiration source signal. | 09-18-2014 |
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 |
20140275889 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION FROM SEGMENTS OF A PHOTOPLETHYSMOGRAPH - A physiological monitoring system may determine respiration information from a PPG signal. The system may analyze the PPG signal with respect to itself by associating values of the PPG signal with values of a time-delayed version of the PPG signal to create pairs of associated values. A subset of associated values may be identified. Respiration metric values may be determined based on the subset of pairs. The respiration metric values may be amplitude values and/or time values corresponding to the subset of pairs. The respiration metric values may be analyzed using autocorrelation, cross-correlation, or other signal processing techniques to determine respiration information such as respiration rate. | 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 |
20140316278 | SYSTEM AND METHOD FOR SCALING A FLUID RESPONSIVENESS METRIC - The present invention relates to physiological signal processing, and in particular to methods and systems for processing physiological signals to predict a fluid responsiveness of a patient. A medical monitor for monitoring a patient may include an input receiving a photoplethysmograph (PPG) signal representing light absorption by a patient's tissue, and a fluid responsiveness predictor (FRP) calculator programmed to calculate an FRP metric. The monitor also may include a memory storing a relationship between the FRP metric and a pulse pressure variation (PPV) metric. The FRP metric is calculated based on a respiratory variation of the PPG signal and based on the relationship. | 10-23-2014 |
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 |
20140323822 | SYSTEM AND METHOD FOR GENERATING AN ADJUSTED FLUID RESPONSIVENESS METRIC - The present invention relates to physiological signal processing, and in particular to methods and systems for processing physiological signals to predict a fluid responsiveness of a patient. A medical monitor for monitoring a patient includes an input receiving a photoplethysmograph (PPG) signal representing light absorption by a patient's tissue. The monitor also includes a perfusion status indicator indicating a perfusion status of the PPG signal, and a fluid responsiveness predictor (FRP) calculator programmed to calculate an FRP value based on a respiratory variation of the PPG signal. The FRP calculator applies a correction factor based on the perfusion status indicator. | 10-30-2014 |
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 |
20140364746 | METHODS AND SYSTEMS FOR RECALIBRATING A BLOOD PRESSURE MONITOR WITH MEMORY - Systems and methods are provided for storing and recalling metrics associated with physiological signals. It may be determined that the value of a monitored physiological metric corresponds to a stored value. In such cases, a patient monitor may determine that a calibration is not desired. In some cases, a patient monitor may recall calibration parameters associated with the stored value if it determined that the stored value corresponds to the monitored metric value. | 12-11-2014 |
20150065829 | SYSTEMS AND METHODS FOR RESPIRATION MONITORING - According to embodiments, techniques for determining respiratory parameters are disclosed. More suitable probe locations for determining respiratory parameters, such as respiration rate and respiratory effort, may be identified. The most suitable probe location may be selected for probe placement. A scalogram may be generated from the detected signal at the more suitable location, resulting in an enhanced breathing band for determining respiratory parameters. Flexible probes that allow for a patient's natural movement due to respiration may also be used to enhance the breathing components of the detected signal. From the enhanced signal, more accurate and reliable respiratory parameters may be determined. | 03-05-2015 |