A system, a wearable device, and a method are provided which can increase the accuracy of physiological metrics while detecting if the patient ingested digital medicine and/or improve performance of the wearable device. The wearable device can comprise machine executable instructions that when executed by the processor, cause the processor to perform various algorithms, such as, for example, at least one of a step count algorithm, a body angle algorithm, a heart rate algorithm, a peak finder algorithm, an adaptive thresholding algorithm, a heart rate variability algorithm, a R-R cleaning Algorithm, a deltaR-R cleaning algorithm, a merge twin interval algorithm, a split tall intervals algorithm, an absorb short intervals algorithm, a bimodal detection algorithm, and a resting algorithm.