A surgical device comprising:a handle assembly (100) including:a power source (144)；at least one motor (153) coupled to the power source； anda controller (143) configured to control the motor；an adapter assembly (200) configured to selectively couple to the handle assembly, the adapter assembly including a strain gauge (320) configured to measure strain；a reload (400) configured to selectively couple to a distal portion of the adapter assembly, the reload including:a plurality of fasteners ("S")；an annular staple pusher (434) for ejecting the plurality of staples； andan anvil assembly (510) selectively couplable to the distal portion of the adapter assembly, the anvil assembly being movable relative to the reload；wherein the controller (143) is configured to control the motor (153) to move the annular staple pusher (434) based on the measured strain.
