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 correlation sequence using two segments of the physiological signal. The system may determine a first correlation lag value that corresponds to a peak in the correlation sequence, and also determine a second correlation lag value equal to a fraction of the first correlation lag value. The fraction may be, for example, one half. The system may qualify or disqualify the correlation lag value based on the correlation value at the second lag value. The system may compare the correlation value at the second lag value to a threshold, to the correlation sequence at the first lag value, or both.

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 identify one or more data points of the sorted difference signal as being associated with noise. For example, one or more end data points may be identified as being associated with noise based on a threshold. The system may determine a value indicative of noise based on the identified data points.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may determine a skew metric based on the physiological signal. The system may determine an algorithm setting based on a reference relationship between the determined skew metric and a value indicative of a physiological rate. 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 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 determine a first metric value indicative of a physiological classification based on the physiological signal. An algorithm setting may be determined based on the physiological classification. The system may determine a second metric value indicative of a different physiological classification based on the physiological signal. A different algorithm may be determined based on the different physiological classification. 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 difference signal based on the physiological signal. The system may determine positive areas associated with positive regions of the difference signal and negative areas associated with negative regions of the difference signal. The system may determine area ratios based on adjacent positive and negative regions of the difference signal. The system may determine an algorithm setting based on the area ratios. 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 receive a calculated value indicative of a physiological rate. The system may determine difference values between a first collection of values of the physiological signal and another collection of corresponding value of the physiological signal spaced from the first collection based on the calculated value. The system may sum the difference values, and qualify or disqualify the calculated value based on the sum. The difference values may have positive and negative values, or the system may calculate an absolute value of each difference value prior to summing. The sum may be compared to a threshold to determine whether to qualify or disqualify the calculated value.

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 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 determine physiological information, such as physiological rate information, from a physiological signal. The system may determine a skew metric based on the physiological signal. The system may also determine a correlation lag value corresponding to a peak in a correlation sequence derived from the physiological signal. The system may qualify or disqualify the correlation lag value based on the skew metric. The system may, for example, compare the skew metric and the correlation lag value to a reference set of skew metric values and correlation lag values to determine whether to qualify or disqualify the correlation lag value.

Abstract: A physiological monitoring system may determine physiological information, such as physiological rate information, from a physiological signal. The system may apply a bandpass filter to the physiological signal to assist in the determination of the physiological information. The system may determine a value indicative of a physiological rate and a metric based on the physiological signal. The system may select one or more settings, such as the center frequency and bandwidth, of the bandpass filter based on the rate and based on the metric, and apply the bandpass filter 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 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: The present invention provides a wide bandwidth, gain flattened Raman amplifier including a laser source of pump radiation, and means for producing from the pump source a plurality of wavelengths of pump radiation including means for providing adjustable optical feedback to the pump source at a plurality of radiation wavelengths. Alternatively, instead of or in addition to the means for providing adjustable optical feedback, the invention may include means for independent power control of each wavelength. The amplifier may include a coupler for coupling the pump radiation into the signal fiber and may include the fiber (which can be the transmission fiber) where the amplification takes place.

Abstract: An optical branching unit is formed of a plurality of interconnected optical interleavers for separating input optical signals into separate components for output on separate branches and for combining separated component optical signals with other input optical signals for output on common branches.

Abstract: An optical branching unit is formed of a plurality of interconnected optical interleavers for separating input optical signals into separate components for output on separate branches and for combining separated component optical signals with other input optical signals for output on common branches.

Abstract: The present invention provides a wide bandwidth, gain flattened Raman amplifier including a laser source of pump radiation, and means for producing from the pump source a plurality of wavelengths of pump radiation including means for providing adjustable optical feedback to the pump source at a plurality of radiation wavelengths. Alternatively, instead of or in addition to the means for providing adjustable optical feedback, the invention may include means for independent power control of each wavelength.