© Springer International Publishing Switzerland 2017. Given the close coupling between wearable devices and the human body, a natural application for these devices is to inform the user of their physiological status. An important point is the potential for wearables to empower the user to monitor his/her own health rather than rely solely on medical professionals or sophisticated medical equipment. This makes it more convenient for the user to monitor certain vital signs more often and this continuous monitoring can prove crucial in diagnosing certain conditions. Pervasive monitoring allows for collection of a large amount of data, which in turn can allow treatments in medicine that are anticipatory rather than reactionary. We emphasize the importance of the design of convenient, wearable physiological sensors by looking in-depth at one specific wearable device called BioWatch, which can be used to non-invasively and continuously measure blood pressure from the wrist.