Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, and other information, such as noise information, from a physiological signal. The system may generate a difference signal based on the physiological signal and sort the difference signal to generate a sorted difference signal. The system may determine slope values for multiple segments of the sorted difference signal. The system may determine two end groups of the segments and determine at least one threshold based on the end groups. One or more end data points of the sorted difference signal may be identified as being associated with noise based on the at least one threshold. The system may determine a value indicative of noise based on the identified data points.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may generate a first difference signal based on the physiological signal. The system may sort the first difference signal to generate a sorted difference signal. The system may generate a second difference signal based on the sorted difference signal. The system may determine an algorithm setting based on the second difference signal. The algorithm setting may, for example, affect the amount of filtering applied to the physiological signal.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may condition the physiological signal to assist in the determination of the physiological information. The system may generate a signal based on a stability function applied to the physiological signal. The stability function may include a Lyapunov function. The system may generate a difference signal based on the stability function, and modify the physiological signal based on the difference signal. The modification may include reducing, or otherwise limiting, some differences between adjacent values in the physiological signal, removing portions of the physiological signal, or other modifications.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

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 physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may receive a calculated value indicative of a physiological rate. Based on the value, the system may select pairs of values of the physiological signal that are particularly spaced. The system may determine a state for each pair of values. The state may correspond to a set of criteria such as, for example, equalities, inequalities, logical operators, or other criteria. The system may determine a number of state transitions based on the determined states, and qualify or disqualify the calculated value based on the number of state transitions.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may generate a lag matrix, which includes multiple segments of the physiological signal each having the same number of values. The system may generate a correlation matrix, which includes multiple correlation values, based on the lag matrix. The system may identify a peak in the correlation lag matrix, or a processed matrix derived thereof, and the corresponding lag value. The correlation matrix, or processed matrix thereof, may be rotated, averaged, or otherwise transformed by the system to identify the lag value. The system may determine physiological rate information based on the identified lag value.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may generate a difference signal based on the physiological signal and sort the difference signal to generate a sorted difference signal. The system may identify a midpoint of a first segment of the difference signal and a midpoint of a second segment of the difference signal. The first segment may correspond to positive values of the difference signal and the second segment may correspond to negative values of the difference signal. The system may determine an algorithm setting based on the first midpoint and the second midpoint. The algorithm setting may, for example, affect the amount of filtering applied to the physiological signal.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may generate a correlation sequence between two segments of the physiological signal at multiple correlation lag values. The system may compare the correlation sequence to a predetermined threshold, which may vary as a function of lag. Based on the comparison, the system may determine whether the correlation sequence value exceeds the threshold, and whether the correlation sequence value corresponds to a peak. The system may identify a lag value when the correlation sequence corresponding to the lag value exceeds the threshold and corresponds to a peak. The system may determine physiological rate information based on the identified lag value.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, and other information, such as noise information, from a physiological signal. The system may generate a first difference signal based on a first segment of the physiological signal and sort the first difference signal to generate a first sorted difference signal. The system may generate a second difference signal based on a second segment of the physiological signal and sort the second difference signal to generate a second sorted difference signal. The first and second sorted difference signals may be analyzed and a value indicative of noise may be determined based on the analysis.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may select two segments of the physiological signal, shifted in time relative to one another by a lag value, and determine a correlation value between the two segments. The system may determine a metric based on the segments, and determine correlation information based on the correlation value and the metric. The metric may be indicative of how well the segments are correlated, providing additional information relative to the correlation value. Based on the metric, the system may modify the correlation value, determine a confidence value, or determine other information. The system may determine physiological rate information based on the correlation information.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.

Abstract: A physiological monitoring system may process a physiological signal such a photoplethysmograph signal from a subject. The system may determine physiological information, such as a physiological rate, from the physiological signal. The system may use search techniques and qualification techniques to determine one or more initialization parameters. The initialization parameters may be used to calculate and qualify a physiological rate. The system may use signal conditioning to reduce noise in the physiological signal and to improve the determination of physiological information. The system may use qualification techniques to confirm determined physiological parameters. The system may also use autocorrelation techniques, cross-correlation techniques, fast start techniques, and/or reference waveforms when processing the physiological signal.