摘要 |
An improved system for detecting sensor off conditions in a pulse oximeter is disclosed. In one implementation, a detector off condition is identified based a volatility of a signal quality of a filtered detector signal. The detector signal is first filtered, for example, to reduce the effects of noise or to otherwise reduce or eliminate components extraneous to the signal of interest. The filtered signal is used to perform a volatility measurement. In this regard, a correlation coefficient may be computed relative to two channels of the filtered signal and a correlation coefficient may be monitored over a moving window to calculate variance values for the correlation coefficient. The resulting variance values may be used alone or in combination with other parameter values to identify a sensor off condition.
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