Handheld electromechanical surgical system

A surgical device comprising:

• an end effector including:
• an anvil assembly;
• a cartridge assembly having a plurality of staples and a longitudinal slot;
• and
• a drive beam movable longitudinally through the anvil assembly and the cartridge assembly from a proximal-most position of the longitudinal slot to a distal-most end of the longitudinal slot, thereby approximating the anvil assembly and the cartridge assembly relative to each other and ejecting the plurality of staples;
• an adapter assembly configured to selectively couple to the end effector, the adapter assembly including an actuation assembly configured to mechanically engage the drive beam and to move the drive beam longitudinally;
• and
• a handle assembly configured to selectively couple to the adapter assembly, the handle assembly including:
• a power source;
• a motor coupled to the power source;
• a sensor configured to measure a force imparted on the drive beam;
• and
• a motor controller configured to control the motor to maintain constant force on the drive beam during ejection of the plurality of staples, wherein constant force is maintained based on the force measured by the sensor during longitudinal movement of the drive beam until the drive beam reaches the distal-most end of the longitudinal slot.

A method for controlling a surgical device, the method comprising:

• activating a motor coupled to a drive beam configured to move longitudinally through an anvil assembly and a longitudinal slot of a cartridge assembly of an end effector from a proximal-most position of the longitudinal slot to a distal-most end of the longitudinal slot;
• approximating the anvil assembly and the cartridge assembly relative to each other;
• ejecting a plurality of staples disposed in the cartridge assembly;
• measuring force imparted on the drive beam;
• and
• controlling the force imparted on the drive beam to remain constant at a setpoint during longitudinal movement of the drive beam while the plurality of staples is ejected, wherein constant force is maintained based on the force measured during longitudinal movement of the drive beam until the drive beam reaches the distal-most end of the longitudinal slot.