Motor-driven surgical cutting and fastening instrument with tactile position feedback

1. A surgical cutting and fastening instrument comprising:

an end effector comprising:

an elongate channel;

a movable cutting instrument for cutting an object positioned in the end effector, and

a clamping member pivotably connected to the elongate channel and wherein said surgical cutting and fastening instrument further comprises:

a main drive shaft assembly connected to the end effector;

a gear drive train connected to the main drive shaft assembly;

a main motor for actuating the gear drive train;

a firing trigger for actuating the main motor;

a tactile position feedback system for applying force to the firing trigger such that the position of the firing trigger is related to the position of the cutting instrument in the end effector;

a closure trigger separate from the firing trigger, wherein retraction of the closure trigger causes the end effector to clamp the object positioned in the end effector; and

a mechanical closure system for closing the end effector when the closure trigger is retracted, said mechanical closure system comprising:

a yoke connected to the closure trigger;

a closure bracket connected to the yoke; and

a closure tube disposed in the closure bracket and connected to the clamping member, wherein retraction of the closure trigger causes the closure tube to move longitudinally such that the clamping member pivots to a clamped position.

2. The surgical cutting and fastening instrument of claim 1 , wherein the tactile position feedback system includes:

an encoder for sensing rotation of the main drive shaft assembly;

a second motor whose rotations are controlled based on the rotations main drive shaft assembly sensed by the encoder; and

an actuating member connected to the second motor, wherein the actuating member is for applying the force to the firing trigger such that position of the firing trigger is related to the position of the cutting instrument in the end effector.

3. The surgical cutting and fastening instrument of claim 2 , wherein the actuating member includes a threaded rod.

4. The surgical cutting and fastening instrument of claim 2 , further comprising a run motor sensor for sensing retracting of the firing trigger, wherein, when retraction of the firing trigger is sensed by the run motor sensor, the main motor is signaled to forward rotate to cause cutting of the object positioned in the end effector by the cutting instrument.

5. The surgical cutting and fastening instrument of claim 4 , wherein the run motor sensor comprises a proportional switch such that the rate of rotation of the main motor is proportional to the retraction force applied to the firing trigger.

6. The surgical cutting and fastening instrument of claim 4 , wherein the run motor sensor comprises an on/off switch.

7. The surgical cutting and fastening instrument of claim 4 , further comprising a control circuit for receiving signals from the encoder related to rotation of the main drive shaft assembly and for sending control signals to the second motor based on the signals received from the encoder.

8. The surgical cutting and fastening instrument of claim 7 , wherein the control circuit is further for:

determining, based on the signals received from the encoder, when the cutting instrument has completed a cutting stroke; and

determining, based on the signals received from the encoder, when the cutting instrument has completed retraction.

9. The surgical cutting and fastening instrument of claim 1 , wherein the end effector includes a staple cartridge.

10. The surgical cutting and fastening instrument of claim 1 , wherein the end effector includes a helical drive screw, such that forward rotation of the helical drive screw causes the cutting instrument to undertake the cutting stroke, and reverse rotation of the helical drive screw causes the cutting instrument to retract.

11. The surgical cutting and fastening instrument of claim 1 , wherein the main drive shaft assembly includes articulation means for articulating the end effector.

12. The surgical cutting and fastening instrument of claim 1 , further comprising a locking mechanism for locking the closure trigger to the handle.

13. A surgical cutting and fastening instrument comprising:

an end effector comprising a moveable cutting instrument for cutting an object positioned in the end effector;

a main drive shaft assembly connected to the end effector; and

a handle connected to the main drive shaft assembly, wherein the handle comprises:

a gear drive train connected to the main drive shaft assembly;

a main motor rotatable in firing direction to apply a firing motion to the gear drive train and a retraction direction to apply a retraction motion to the gear drive train;

a firing trigger for actuating the main motor upon application of an actuation force thereto; and

a run motor sensor communicating with said main motor and configured to sense actuation of the firing trigger such that when the firing trigger is actuated, the run motor sensor signals to the main motor to rotate in the firing direction at a firing rate proportional to the actuation force applied to the firing trigger and wherein:

as the firing trigger is actuated by a user, the user experiences through the firing trigger a resistance related to a loading force experienced by the cutting instrument as it cuts through the object positioned in the end effector; and

after the cutting instrument has cut through the object, the user experiences a retraction force through the firing trigger that is proportional to a retraction speed of the motor.

14. The surgical cutting and fastening instrument of claim 13 , wherein the end effector comprises:

an elongate channel for carrying the cutting instrument; and

a clamping member pivotably connected to the elongate channel.