Devices, systems, and methods for torque amplification in medical systems

1. A medical device comprising:

a main shaft extending from a proximal end to a distal end;

an actuator at a proximal portion of the medical device;

an end effector positioned at a distal end of the main shaft and comprising a first jaw and a second jaw;

a motor; and

a torque amplification system comprising:

a driveshaft coupled to the motor;

a spring coupled to the driveshaft and configured to expand or contract in a proximal or a distal direction relative to the driveshaft;

a hammer moveably coupled to the driveshaft; and

an anvil coupled to the end effector and abutting the hammer, wherein the anvil is configured to provide a rotational power output to the end effector to move the first jaw and/or the second jaw.

2. The medical device of claim 1 , wherein the motor is positioned within a distal portion of the main shaft.

3. The medical device of claim 1 , further comprising a handle coupled to the proximal end of the main shaft, wherein the actuator is positioned on the handle.

4. The medical device of claim 1 , wherein the end effector is an endoscopic stapler, a grasper, forceps, or scissors.

5. The medical device of claim 1 , wherein:

the hammer includes a first flange extending distally from a distal face of hammer;

the anvil includes a second flange extending proximally from a proximal face of the anvil; and

the first flange is configured to engage the second flange to rotate anvil about a central longitudinal axis of the anvil.

6. The medical device of claim 5 , wherein:

the hammer is cylindrical and includes an inner tubular portion;

the inner tubular portion includes a channel extending transverse to a central longitudinal axis of the hammer;

the driveshaft includes a ball bearing coupled to a distal end of the driveshaft; and

the ball bearing is movably positioned within the channel.

7. The medical device of claim 6 , wherein the spring extends circumferentially around a radially-outer surface of the driveshaft and abuts a proximal end of the inner tubular portion.

8. The medical device of claim 7 , wherein the torque amplification system further comprises a central, longitudinal lumen extending through the driveshaft, the hammer, the spring, and the anvil.

9. The medical device of claim 1 , wherein each of the hammer and the anvil is cylindrical; and wherein the hammer has a diameter substantially the same as the diameter of the anvil.

10. The medical device of claim 1 , wherein:

the driveshaft includes (i) a recess extending longitudinally through the driveshaft from a distal end of the driveshaft, and (ii) a pair of channels extending proximally from the distal end;

the spring is positioned with the recess; and

the hammer includes (i) a pair of protrusions extending proximally from a proximal face of the hammer, wherein each of the pair of protrusions are configured to be received by each of the pair of channels, respectively; and (ii) a pair of flanges extending distally from a distal end face of hammer.

11. The medical device of claim 10 , wherein the anvil is T-shaped.

12. The medical device of claim 1 , wherein:

the driveshaft includes a first recess;

the hammer includes a second recess and a pair of protrusions extending distally from a distal face of the hammer;

the spring is positioned within the first recess and a distal end of the spring is fixedly coupled to a proximally-facing surface within the second recess; and

a distal portion of the driveshaft is received within the second recess.

13. The medical device of claim 12 , wherein:

the hammer includes a first channel within the second recess;

the driveshaft includes a second channel in a radially-outward surface, relative to a central longitudinal axis, of the driveshaft; and

a ball bearing is positioned between the first channel and the second channel.

14. The medical device of claim 12 , wherein the spring is conical.

15. The medical device of claim 1 , further comprising a ratchet mechanism coupled to the driveshaft.

16. A medical device comprising:

an end effector; and

a torque amplification system comprising:

a driveshaft coupled to the motor;

a spring coupled to the driveshaft and configured to expand or contract in a proximal or a distal direction relative to the driveshaft;

a hammer moveably coupled to the driveshaft;

an anvil coupled to an output shaft and abutting the hammer, wherein the anvil is configured to provide a rotational power output to the output shaft; and

a lumen extending along a central longitudinal axis of the torque amplification system, wherein the lumen extends through the driveshaft, the spring, the hammer, and the anvil;

wherein the output shaft is coupled to the end effector.

17. The medical device of claim 16 , wherein:

the hammer is cylindrical and includes an inner tubular portion;

the inner tubular portion includes a channel extending transverse to a central longitudinal axis of the hammer;

the driveshaft includes a ball bearing coupled to a distal end of the driveshaft;

the ball bearing is movably positioned within the channel; and

the spring extends circumferentially around a radially-outer surface of the driveshaft and abuts a proximal end of the inner tubular portion.

18. The medical device of claim 16 , wherein:

the driveshaft includes (i) a recess extending longitudinally through the driveshaft from a distal end of the driveshaft, and (ii) a pair of channels extending proximally from the distal end of the driveshaft;

the spring is positioned with the recess; and

the hammer includes (i) a pair of protrusions extending proximally from a proximal face of the hammer, wherein each of the pair of protrusions are configured to be received by each of the pair of channels, respectively; and (ii) a pair of flanges extending distally from a distal end face of hammer.

19. The medical device of claim 16 , wherein:

the driveshaft includes a first recess;

the hammer includes a second recess, a pair of protrusions extending distally from a distal face of hammer, and a first channel within the second recess;

the spring is positioned within the first recess and a distal end of the spring is fixedly coupled to a proximally-facing surface within the second recess;

a distal portion of the driveshaft is received within the second recess;

the driveshaft includes a second channel in a radially-outward surface, relative to a central longitudinal axis, of the driveshaft; and

a ball bearing is movably positioned between the first channel and the second channel.

20. A medical device comprising:

a shaft extending longitudinally from a proximal end portion to a distal end portion;

a motor positioned within the distal end portion;

an end effector at the distal end portion; and

a torque amplification system comprising:

a driveshaft coupled to the motor;

a spring coupled to the driveshaft and configured to move relative to the driveshaft;

a hammer moveably coupled to the driveshaft; and

an anvil coupled to the end effector and abutting the hammer, wherein the anvil is configured to provide a rotational power output to the end effector.