Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Methods and systems are provided for determining fluid responsiveness based on physiological signals. The system may detect gain changes or excessive baseline modulations. In some embodiments, based on the detected gain changes or excessive baseline modulations, the system may ignore portions of physiological signals and determine a parameter indicative of fluid responsiveness based on a plurality of amplitudes determined from other portions of the physiological signals. In some embodiments, based on the detected gain changes or excessive baseline modulations, the system may determine fluid responsiveness, or refrain from determining fluid responsiveness.

Abstract: 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.

Abstract: 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.

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: Methods and systems are provided for disinfecting and recharging a sensor. The sensor may be a wireless sensor, or the sensor may be configured to operate in a wireless mode and in a wired mode. The system may include a charging device configured to provide power to the sensor and/or to recharge a power source of the sensor. The sensor may include a proximity detector configured to provide information relating to a proximity of the sensor to the charging device. Additionally, the sensor may include additional sensors configured to provide information relating to a disinfection process utilized to disinfect the sensor.

Abstract: Methods and systems are disclosed for analyzing a physiological respiratory signal in order to monitor respiratory depression events. In certain embodiments, respiratory depression is monitored by extracting a respiratory signal from a photoplethysmograph (“PPG”) signal, identifying a morphological characteristic of the respiratory signal, and generating a respiratory condition signal. In certain embodiments, an alarm and therapeutic intervention strategy are triggered upon determination of respiratory depression event.

Abstract: Systems and methods provided relate to patient sensors and/or patient monitors that recognize and/or identify a patient with physiological signals obtained from the sensor. A scalogram may be produced by applying a wavelet transform for the physiological signals obtained from the sensor. The scalogram may be a three dimensional model (having time, scale, and magnitude) from which certain physiological information may be obtained. For example, unique human physiological characteristics, also known as biometrics, may be determined from the scalograms. More specifically, monitoring the changes in the morphology of the photoplethysmographic (PPG) waveform transforms (e.g., scalogram) may determine patient-specific information that may be used to recognize and/or identify the patient, and that may be used to determine a proper or improper association between the patient and the wireless sensor and/or patient monitor.

Abstract: 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).

Abstract: 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.

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: Various methods and systems for ensemble averaging signals in a pulse oximeter are provided. An ensemble averaging method includes receiving an ensemble average signal corresponding to an ensemble average of electromagnetic radiation signals detected from a blood perfused tissue of a patient and receiving a pulse signal corresponding to a pulse detected by the pulse oximeter. The method also includes scaling a width of the ensemble average signal, a width of the pulse signal, or both to produce a scaled ensemble average signal and a scaled pulse signal having a substantially uniform width. The method further includes ensemble averaging the scaled ensemble average signal and the scaled pulse signal to produce an updated ensemble average signal having the substantially uniform width.

Abstract: 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.

Abstract: A system includes a controller that receives a physiological signal representing a non-invasive measure of a physiological parameter. The controller applies a compliance metric to the physiological signal and generates an autoregulation status signal that indicates a status of cerebral autoregulation in the patient. The autoregulation status signal is based at least in part on the compliance metric applied to the physiological signal.

Abstract: A system includes a controller that receives a blood pressure signal and an oxygen saturation signal. The blood pressure signal represents a non-invasive measure of blood pressure. The oxygen saturation signal represents a non-invasive measure of oxygen saturation. The controller generates an autoregulation status signal representing a status of cerebral autoregulation. The autoregulation status signal is based, at least in part, on a relationship between the measured blood pressure and the measured oxygen saturation. An exemplary method may include receiving the blood pressure signal and the oxygen saturation signal, defining a relationship between the measured blood pressure and the measured oxygen saturation, determining an autoregulation status based at least in part on the defined relationship, and generating an autoregulation status signal representing the determined autoregulation status.

Abstract: 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.

Abstract: 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.

Abstract: 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.