An optical motion sensing device included a sensor frame defining an
opening, a sensor pad disposed in the opening, an optical sensing system
adapted to detect an amount of movement of the sensor pad in the sensor
frame, and an output unit. The optical sensing system includes an optical
waveguide, an optical source device, and an optical detector. The optical
waveguide is positioned within the sensor frame such that the movement of
the sensor pad results in the flexing or compressing of the optical
waveguide. The optical source device supplies optical energy to the
optical waveguide. The optical detector detects an amount of optical
energy exiting the optical waveguide. The output unit is configured to
receive a signal indicative of the amount of optical energy exiting the
optical waveguide and to generate a measure of the amount of movement of
the sensor pad from the received signal.