Patents Assigned to Nèllcor Puritan Bennett Ireland
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Publication number: 20140012147Abstract: A blood pressure measurement system is configured to perform a calibration automatically when a calibration condition is satisfied. The calibration condition is based upon one or more parameters of pulse waves of a subject. The parameters may include pulse wave area; a time difference between systolic peak and reflected wave peak or dichrotic notch in the pulse wave and a shape of at least a portion of the pulse wave.Type: ApplicationFiled: September 9, 2013Publication date: January 9, 2014Applicant: Nellcor Puritan Bennett IrelandInventors: Luya Li, Rakesh Kumar Sethi, Ming Sun, Alexander Yuk Sit, Yong Liu
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Publication number: 20140012109Abstract: According to embodiments, techniques for selecting a consistent part of a signal, including a photoplethysmograph (PPG) signal, are disclosed. A pulse oximetry system including a sensor or probe may be used to obtain a PPG signal from a subject. Signal peaks may be identified in the PPG signal. Characteristics of the signal peaks, including the amplitude levels of the signal peaks and/or the time-distance between the signal peaks may be used to determine if the PPG signal is consistent. In an embodiment, signal peaks are processed based on a consistency metric, and the processed signal peaks are compared to the consistency metric to determine if the PPG signal is consistent. If the PPG signal is determined to be consistent, the PPG signal may be further analyzed to determine an underlying signal parameter, including, for example, a patient respiration rate.Type: ApplicationFiled: September 6, 2013Publication date: January 9, 2014Applicant: Nellcor Puritan Bennett IrelandInventors: Scott McGonigle, Paul S. Addison, James N. Watson
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Publication number: 20140012110Abstract: 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.Type: ApplicationFiled: September 6, 2013Publication date: January 9, 2014Applicant: Nellcor Puritan Bennett IrelandInventors: James Nicholas Watson, Paul Stanley Addison
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Patent number: 8618947Abstract: 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.Type: GrantFiled: March 29, 2013Date of Patent: December 31, 2013Assignee: Nellcor Puritan Bennett IrelandInventors: James Nicholas Watson, Paul Stanley Addison
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Patent number: 8594759Abstract: 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.Type: GrantFiled: July 30, 2009Date of Patent: November 26, 2013Assignee: Nellcor Puritan Bennett IrelandInventors: Braddon M. Van Slyke, Paul Stanley Addison, James Nicholas Watson
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Publication number: 20130296659Abstract: The present disclosure relates generally to patient monitoring systems and, more particularly, to signal analysis for patient monitoring systems. In one embodiment, a method of analyzing a detector signal of a physiological patient sensor includes obtaining the detector signal from the physiological patient sensor, and determining a ratio of the signal between two or more channels. A distribution of the angles between the points of the ratio over time may be used to determine a true ratio or a ratio of ratios for use in the determination of a physiological parameter.Type: ApplicationFiled: May 1, 2012Publication date: November 7, 2013Applicant: Nellcor Puritan Bennett IrelandInventors: Paul Addison, James Ochs, James Watson
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Patent number: 8574162Abstract: According to embodiments, systems and methods are provided for detecting pulses in a PPG signal. Local minima and maxima points may be identified in the PPG signal. Each minimum may be paired with an adjacent maximum forming an upstroke segment. Noise may be removed by comparing adjacent segments and ignoring segments that are too long or too large. Notches in the pulse may be identified and ignored by analyzing adjacent segments. Adjacent upstroke segments may be combined as a single upstroke if the lengths of adjacent upstroke segments are about the same, have similar slopes, and the end point of one segment is close to the start point of an adjacent segment. Segments having small temporal or amplitude difference relative to adjacent segments may be disregarded. The remaining segments may represent the pulse upticks. A sliding time window may be used instead to detect pulses in the PPG signal.Type: GrantFiled: September 30, 2008Date of Patent: November 5, 2013Assignee: Nellcor Puritan Bennett IrelandInventor: James Watson
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Publication number: 20130289413Abstract: A patient monitoring system may determine portions of a PPG signal that correspond to artifacts, to a baseline shift that exceeds a threshold, or to a pulse-to-pulse variability that exceeds a threshold. The patient monitoring system may identify a contiguous portion of the PPG signal that does not include the determined portions. The contiguous portion of the PPG signal may be used to determine physiological information.Type: ApplicationFiled: April 30, 2012Publication date: October 31, 2013Applicant: Nellcor Puritan Bennett IrelandInventors: James Ochs, Scott McGonigle, Paul Addison, James Watson
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Patent number: 8560245Abstract: A blood pressure measurement system is configured to perform a calibration automatically when a calibration condition is satisfied. The calibration condition is based upon one or more parameters of pulse waves of a subject. The parameters may include pulse wave area; a time difference between systolic peak and reflected wave peak or dichrotic notch in the pulse wave and a shape of at least a portion of the pulse wave.Type: GrantFiled: November 21, 2008Date of Patent: October 15, 2013Assignee: Nellcor Puritan Bennett IrelandInventors: Luya Li, Rakesh Kumar Sethi, Ming Sun, Alexander Yuk Sit, Yong Liu
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Publication number: 20130253341Abstract: According to some embodiments, systems and methods are provided for non-invasive continuous blood pressure determination. In some embodiments, a PPG signal is received and locations of pulses within the PPG signal are identified. An area within a particular pulse is measured. The area may be of just the upstroke, downstroke or the entire pulse. The area may be measured relative to a time-domain axis or a baseline of the pulse. The pulse may be split into multiple sections and the area of each section may be measured. The area of one portion of the pulse may correspond to systolic blood pressure while the area of another portion may correspond to diastolic blood pressure. Empirical data may be used to determine blood pressure from the measured area by applying calibration data measured by a suitable device.Type: ApplicationFiled: March 13, 2013Publication date: September 26, 2013Applicant: NELLCOR PURITAN BENNETT IRELANDInventors: Rakesh Sethi, James Watson
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Publication number: 20130245482Abstract: 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.Type: ApplicationFiled: May 1, 2013Publication date: September 19, 2013Applicant: Nellcor Puritan Bennett IrelandInventors: Scott McGonigle, Paul Stanley Addison, James Nicholas Watson
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Patent number: 8532932Abstract: According to embodiments, techniques for selecting a consistent part of a signal, including a photoplethysmograph (PPG) signal, are disclosed. A pulse oximetry system including a sensor or probe may be used to obtain a PPG signal from a subject. Signal peaks may be identified in the PPG signal. Characteristics of the signal peaks, including the amplitude levels of the signal peaks and/or the time-distance between the signal peaks may be used to determine if the PPG signal is consistent. In an embodiment, signal peaks are processed based on a consistency metric, and the processed signal peaks are compared to the consistency metric to determine if the PPG signal is consistent. If the PPG signal is determined to be consistent, the PPG signal may be further analyzed to determine an underlying signal parameter, including, for example, a patient respiration rate.Type: GrantFiled: May 7, 2009Date of Patent: September 10, 2013Assignee: Nellcor Puritan Bennett IrelandInventors: Scott McGonigle, Paul S. Addison, James N. Watson
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Publication number: 20130229285Abstract: 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.Type: ApplicationFiled: March 29, 2013Publication date: September 5, 2013Applicant: NELLCOR PURITAN BENNETT IRELANDInventors: James Nicholas Watson, Paul Stanley Addison
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Publication number: 20130211235Abstract: 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.Type: ApplicationFiled: March 15, 2013Publication date: August 15, 2013Applicant: NELLCOR PURITAN BENNETT IRELANDInventor: NELLCOR PURITAN BENNETT IRELAND
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Patent number: 8506498Abstract: 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.Type: GrantFiled: October 9, 2008Date of Patent: August 13, 2013Assignee: Nellcor Puritan Bennett IrelandInventors: Rakesh Sethi, Paul Stanley Addison, James Nicholas Watson
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Publication number: 20130197329Abstract: 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.Type: ApplicationFiled: December 22, 2012Publication date: August 1, 2013Applicant: NELLCOR PURITAN BENNETT IRELANDInventor: NELLCOR PURITAN BENNETT IRELAND
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Patent number: 8483459Abstract: 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.Type: GrantFiled: July 12, 2012Date of Patent: July 9, 2013Assignee: Nèllcor Puritan Bennett IrelandInventors: James Nicholas Watson, Paul Stanley Addison, David Clifton
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Publication number: 20130172767Abstract: A patient monitoring system may receive a physiological signal such as a photoplethysmograph (PPG) signal that exhibits frequency and amplitude modulation based on respiration. A phase locked loop may generate a frequency demodulated signal and an amplitude demodulated signal from the PPG signal. An autocorrelation sequence may be generated for each of the frequency demodulated signal and the amplitude demodulated signal. The autocorrelation sequences may be combined and respiration information may be determined based on the combined autocorrelation sequence.Type: ApplicationFiled: January 4, 2012Publication date: July 4, 2013Applicant: Nellcor Puritan Bennett IrelandInventors: James Dripps, James Ochs, Paul S. Addison
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Publication number: 20130172686Abstract: A patient monitoring system may receive a physiological signal having gap portions in the received data. The gap portions may be identified and a plurality of morphology metric signals may be modified based on the identified gap portions. The morphology metric signals may be modified based on the identified gaps, and a combined autocorrelation sequence may be generated based on the modified morphology metric signals. The combined autocorrelation sequence may be used to determine physiological information.Type: ApplicationFiled: January 4, 2012Publication date: July 4, 2013Applicant: Nellcor Puritan Bennett IrelandInventors: Paul S. Addison, James Dripps, James Ochs, James Watson
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Patent number: 8478538Abstract: According to embodiments, techniques for extracting a signal parameter from a selected region of a generally repetitive signal are disclosed. A pulse oximetry system including a sensor or probe may be used to obtain an original photoplethysmograph (PPG) signal from a subject. A filter transformation may be applied to the original PPG signal to produce a baseline PPG signal. The baseline PPG signal may contain artifacts and/or noise, and a region of the baseline PPG signal suitable for extracting the signal parameter may be selected. A suitable region of the baseline PPG signal may be selected by applying one or more thresholds to the baseline PPG signal, where the values of the thresholds may be set based on derivative values, amplitude-based percentiles, and/or local minima and maxima of the baseline PPG signal. A portion of the original PPG signal corresponding to the selected region may be processed, and the signal parameter may be extracted from the processed region.Type: GrantFiled: May 7, 2009Date of Patent: July 2, 2013Assignee: Nellcor Puritan Bennett IrelandInventors: Scott McGonigle, Paul S. Addison, James N. Watson