Abstract: Various devices, systems, methods, and apparatuses utilize mechanical assemblies to prevent, detect, and/or mitigate objects from entering or moving close to or under a treadmill or exercise machine. In some embodiments, a guard, or guard assembly, is attached or otherwise fixed to a rear area of a treadmill. The guard assembly may include an end cap and pivoting guard configured to be retrofit to existing treadmills, such as to a rear end or area of a deck or frame of a treadmill.

Abstract: A shell containing axles, magnets, electronics and diodes that provide for a more efficient generation of electricity. A tubular shell containing a spinning axle, fitted with magnets, magnetic bearings, computer to regulate and control generation functions provides power generation at a higher output to input power ratio than previously seen.

Abstract: A method is provided for tracking an object's position. One or more semiconductor-based sensors obtain measurements of an energy field associated with the object. A processor applies an algorithm to the measurements to generate one or more values representing a position of the object in a coordinate system. The energy field may comprise a magnetic field, for example. The object may comprise a magnet, for example.