Patent ID: 7721936

Claim:
A surgical instrument, comprising: an end effector comprising: a cutting instrument actuable to cut an object; a longitudinally extending channel, the channel having a proximal end and a distal end; an anvil pivotally attached to the channel, wherein the object is positionable between the anvil and the channel; a staple cartridge removably seated in the channel, the staple cartridge having a proximal end and a distal end; a firing drive slot formed between the cartridge and the channel through which at least a portion of the cutting instrument passes when the cutting instrument is actuated; and a sled disposed in the staple cartridge, wherein when the cutting instrument is actuated the sled is engaged by the cutting instrument and driven longitudinally through the staple cartridge from an unfired position located at the proximal end of the staple cartridge to a fired position located at the distal end of the staple cartridge; a motor coupled to the end effector to actuate the cutting instrument; and an interlock coupled to the end effector and to the motor, the interlock to prevent actuation of the cutting instrument based on a current through the motor, the interlock comprising: a blocking mechanism to prevent actuation of the cutting instrument when the sled is not present in the unfired position; and a lockout circuit to sense the current through the motor and to interrupt the current through the motor based on the sensed current.