A prosthetic suspension device having a positioning element, a coupling element, and a friction-reducing element to facilitate movement of the positioning element towards the coupling element. In addition, a method of fabricating such a flexible film optical waveguide is also provided. The picker may include a hydraulic fluid to hydraulically couple at least two components, such as a moveable pump component and a cannula. Response times, resource utilizations, and resource queue lengths are initially estimated for a small user arrival rate. According to another embodiment, an image forming apparatus includes an image forming unit which forms an image on a recording medium, the erasing unit, the input unit, and the control unit.