Abstract: A vital sign measurement device includes an optical sensing system and an output unit. The optical sensing system includes an optical source, an optical refractor, and an optical detector. The optical sensing system is placed against the anatomical location of the subject to sense movement corresponding to an arterial pulse. The optical sensing system can sense an arterial pulse from the movement, bending, or compression of at least one portion of the optical sensing system relative to other portions of the optical sensing system resulting in a change in an optical signal received by the optical detector. The output unit generates a measure of a vital sign.