In some embodiments, a system comprises a wearable member configured to receive first energy, generate first signals, select a first subset of the time series data, determine a standard deviation indicating a quality at a low percentile of values associated with first windows of the time series data and a high percentile of values associated with the first windows of the time series data, the signal assessment threshold being including at least the values of the lower percentile, receive second energy, generate second signals containing second time series data from the second energy, select a second subset of the time series data to assess, compare all or part of the second signals to the signal assessment threshold, and if all or part of the second signals include the second time series data that is within the values of the lower percentile, then remove the second signals from further processing.