A method and system for determining a signal quality metric of a cardiovascular time series utilizing a wireless sensor device are disclosed. In a first aspect, the method comprises determining subsequent values of the cardiovascular time series and comparing the determined subsequent values to a threshold value. In a second aspect, a wireless sensor device comprises a processor and a memory device coupled to the processor, wherein the memory device includes an application that, when executed by the processor, causes the processor to determine subsequent values of the cardiovascular time series and compare the determined subsequent values to a threshold value.