An image input apparatus reliably detects occurrence of an error in the receiving of a plurality of image signals for obtaining a high-resolution still image, and prevents time loss caused by meaningless processing in a later stage of processing. In a particular embodiment, a system is disclosed that comprises a memory and a performance governor circuit coupled to the memory. A V-drill guide is provided with a handle and two drill sleeves having intersecting trajectories for creating an intersecting V-shaped bone tunnel in the ulna.