POWER PEDICLE SCREWDRIVER

• US 20180042650A1
• Filed: 08/10/2017
• Published: 02/15/2018
• Est. Priority Date: 08/11/2016
• Status: Active Grant

• Current Assignee: MAKO Surgical Corporation (Stryker Corporation)
• Original Assignee: MAKO Surgical Corporation (Stryker Corporation)
• Inventors: Gao, Xiao Hui, Kang, Hyosig, Lee, Daryle
• Granted Patent: US 10,561,448 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 17/7082 for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws driving other bone screws A61B17/8875
• CPC Class Codes: A61B 17/8875 Screwdrivers, spanners or wrenches
• CPC Class Codes: A61B 2017/00398 using powered actuators, e.g. stepper motors, solenoids
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/564 Methods for bone or joint treatment
• CPC Class Codes: A61B 2034/303 specifically adapted for manipulations within body lumens, e.g. within lumen of gut, spine, or blood vessels
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: B25F 5/001 Gearings, speed selectors, clutches or the like specially adapted for rotary tools

Abstract

Disclosed herein are gear shifters to reverse an output shaft rotation and a method for using the same. A gear shifter in accordance with the present invention may include a housing, an input shaft, an output shaft and an idler shaft. The input shaft may have input gears, the output shaft may have output gears and the idler shaft may have idler gears. The output shaft may be slidably coupled with the input shaft and the idler shaft to rotate in a first direction in a first position and in a second opposite direction in a second position. A method of reversing an output shaft direction using a gear shifter may include the steps of pushing the gear shifter in a first direction to rotate the output shaft in a first direction and pushing the gear shifter in a second direction to rotate the output shaft in a second direction.

Claims

1. A gear shifter comprising:

a housing;

an input shaft with a first input gear, a first side of the input shaft within the housing and a second side of the input shaft extending from the housing;

an output shaft with a first output gear, a first side of the output shaft within the housing and a second side of the output shaft extending from the housing;

an idler shaft with a first idler gear,

wherein the output shaft is slidably coupled with the input shaft and rotates in an opposite direction of the input shaft when the housing is in a first position, and the output shaft is slidably coupled with the idler shaft and rotates in the same direction as the input shaft when the housing is in a second position.

2. The gear shifter of claim 1, further comprising a second input gear on the input shaft, a second output gear on the output shaft and a second idler gear on the idler shaft, wherein the first idler gear is coupled to the first input gear.

3. The gear shifter of claim 2, wherein the first output gear is coupled with the second input gear to couple the output shaft with the input shaft when the housing is in the first position.

4. The gear shifter of claim 2, wherein the second output gear is coupled with the second idler gear to couple the output shaft with the idler shaft when the housing is in the second position.

5. The gear shifter of claim 2, wherein the input shaft, the output shaft and the idler shaft are parallel to each other.

6. The gear shifter of claim 2, wherein the input gears, output gears and idler gears are axially located helical gears.

7. The gear shifter of claim 2, wherein the output shaft is disposed over the inner shaft, the inner shaft being coaxial to the output shaft and extending from the output shaft in a distal and a proximal direction.

8. The gear shifter of claim 7, wherein the output shaft and the input shaft rotate independent of the other.

9. The gear shifter of claim 7, wherein the output shaft has external helical threading on a distal end.

10. The gear shifter of claim 7, wherein a distal end of the inner shaft is a screw engaging surface.

11. The gear shifter of claim 10, wherein the screw engaging surface is configured to interface with a pedicle screw head.

12. The gear shifter of claim 2, wherein a proximal end of the inner shaft is attached to the housing by a first spring, and a proximal end of the outer shaft is attached to the housing by a second spring such that the input gears are pushed towards a distal end of the housing.

13. The gear shifter housing of claim 2, wherein the input gears are housed in a first chamber, the idler gears are housed in a second chamber and the output gears are housed in a third chamber.

14. A method of inserting a pedicle screw comprising the steps of:

engaging an output shaft of a gear shifter with a pedicle screw, the gear shifter being in a first position;

inserting the pedicle screw in a pedicle of a vertebral body, with the gear shifter remaining in the first position;

moving the gear shifter to a second position;

disengaging the output shaft from the pedicle screw, with the gear shifter in the second position.

15. The method of claim 14, wherein the gear shifter is moved from the first position to the second position in the same direction as the disengagement of the output shaft from the pedicle screw.

16. A method of reversing an output shaft direction driven by a unidirectional input shaft using a gear shifter, comprising the steps of:

attaching the input shaft to a first end of the gear shifter;

attaching the output shaft to a second end of the gear shifter;

pushing the gear shifter in a distal direction to rotate the output shaft in a first direction, and

pushing the gear shifter in a proximal direction to rotate the output shaft in a second direction.

17. The method according to claim 16, wherein the gear shifter comprises of a pair of input gears on the input shaft, a pair of idler gears on an idler shaft and a pair of output gears on the output shaft.

18. The method according to claim 16, wherein the output shaft is a pedicle screwdriver with an outer shaft having external threads at a distal end and disposed around an inner shaft, the inner shaft being coaxial to the outer shaft and extending from the outer shaft in a distal and a proximal direction, the inner shaft having a screw engaging distal end.

19. The method according to claim 18, wherein the step of pushing the gear shifter in the distal direction rotates the inner shaft in a clockwise direction to insert a pedicle screw into a vertebral body.

20. The method according to claim 18, wherein the step of pushing the gear shifter in a proximal direction rotates the outer shaft of the pedicle screwdriver to retract the pedicle screwdriver without rotating the inner shaft.

21. The method according to claim 16, wherein the input shaft is coupled to a robotic arm configured for robotic surgery.