Powered surgical stapling device
A medical instrument having a tool assembly including a pair of opposing tissue engaging surfaces for clamping tissue therebetween. The medical instrument includes a housing having a fixed handle and a movable handle mounted to the housing and selectively movable relative to the fixed handle from a first position in spaced relation relative to the fixed handle to a second position closer to the fixed handle to actuate the clamping of tissue. The medical instrument includes a selectively activatable drive assembly including a power source and a motor which is operatively coupled to the movable handle, wherein upon actuation the motor actuates the pair of opposing tissue engaging surfaces. The drive assembly includes a controller configured to variably control the rate at which the motor actuates the pair of opposing tissue engaging surfaces in response to the force exerted on the movable handle.
1. A drive assembly for use with a surgical device, comprising:
a motor;
a firing shaft operably coupled to the motor; and
a controller, wherein the motor is configured to be actuated by the controller at a variably controlled rate in response to a longitudinal motion applied to the firing shaft.
2. The drive assembly according to claim 1 , wherein the motor is incorporated within a housing.
3. The drive assembly according to claim 1 , wherein the controller is configured to variably control a voltage supplied to the motor in response to the longitudinal motion applied to the firing shaft.
4. The drive assembly according to claim 1 , wherein the firing shaft is configured to actuate an end effector associated with a surgical device.
5. The drive assembly according to claim 1 , wherein the firing shaft is operatively coupled to the motor via a coupling member, the coupling member including a ratchet track having one or more teeth interfacing with a pawl.
6. The drive assembly according to claim 1 , further including a power source operatively connected to the motor.
7. The drive assembly according to claim 6 , further including a variable resistor coupled to the motor and the power source, the variable resistor controlling a rate at which the firing shaft is longitudinally displaced.
8. The drive assembly according to claim 6 , further including a switch assembly coupled to the motor and the power source.
9. The drive assembly according to claim 8 , wherein the switch assembly includes a pressure sensor and a switch handle.
10. The drive assembly according to claim 9 , wherein the pressure sensor is a piezoelectric sensor configured to sense pressure applied to the switch handle.
11. The drive assembly according to claim 10 , wherein the pressure sensor records pressure applied on the switch handle as sensor signals, the sensor signals being representative of clamping force.