Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.