US Patent 9078671 Surgical tool

A tool for use during surgery includes a housing including a distal end and a proximal end, a motor disposed within the housing, and an output shaft having a proximal end connected to the motor and a distal end extending from the distal end of the housing. The tool further includes a battery pack contained within the housing, and a passage extending from the distal end to the proximal end of the housing through the output shaft and the battery pack, wherein the passage is defined by an interior surface of the output shaft and a channel through the battery.