A system and method for a biological interface system that processes multicellular signals of a patient and controls one or more devices is disclosed. Typically, wear reduction features, such as hardened materials, are used to minimize the amount of wear or direct such wear to a specific component. It also comprises a hierarchical series of motion estimators of varying complexity, for estimating a motion vector field between the received image and a reference image. Additional targets are provided, including a target defined by a vertically oriented post positioned proximate an end of a horizontal rung and perpendicular thereto. The first ornamental theme and the second ornamental theme are thematically related so as to create a surrounding ornamentation of the footwear. The current sensing circuit includes a sample and hold circuit, a rising edge detecting circuit, a falling edge detecting circuit, a timing control circuit, a synchronous detecting circuit and a low pass filter.