A fastener apparatus includes a handle, an elongate body connected to the handle, a fastener cartridge disposed adjacent the distal end of the elongate body and having at least one fastener, a pusher at least partially disposed within the elongate body, and adapted for longitudinal movement through a firing stroke to eject the at least one fastener from the fastener cartridge, a linear position sensor mounted within the elongate body and dimensioned and positioned to engage the pusher during movement through the firing stroke and being adapted to send at least one output signal representative of strain imparted thereupon by the pusher during the firing stroke, and a controller configured and adapted to determine a position of the pusher within the firing stroke based upon the at least one output signal.
