Patent ID: 8915869

Claim:
A measurement device for use with one or more external devices, the measurement device comprising: a reflective gradient configured to reflect radiation, reflectivity of reflective gradient varying along a gradient direction; and a circuit connecting a processor to one or more sensors and a communication mechanism, each of the one or more sensors comprising an emitter and a corresponding detector positionable relative to the reflective gradient along the gradient direction, the processor being configured to: (a) instruct the emitter of each of the one or more sensors to emit radiation, at least a portion of the radiation emitted by the emitter of each of the one or more sensors positioned adjacent a portion of the reflective gradient being reflected by the portion of the reflective gradient toward the corresponding detector, (b) instruct the detector of each of the one or more sensors to detect a reflected amount of radiation, the reflected amount of radiation indicating whereat along the reflective gradient the sensor is positioned, and (c) instruct the communication mechanism to transmit, to the one or more external devices, measurement information based on the reflected amount of radiation detected by the detector of each of the one or more sensors.