Slanted drive axis rotary surgical cutting tools and powered handpieces

Patent metadata

Field	Value
Publication number	US-10314610-B2
Application number	US-201615072492-A
Country	US
Kind code	B2
Filing date	Mar 17, 2016
Priority date	Mar 25, 2015
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A surgical cutting tool adapted to be rotatably driven by a motor. The surgical cutting tool includes an elongated shaft defining intermediate and coupling portions. A shape of the intermediate portion defines a primary central axis of the shaft. The coupling portion includes a tang having a tapered cylindrical shape that defines a drive axis. The drive axis is slanted with respect to the primary central axis. When coupled to the motor of a powered handpiece, the tang transmits an input or drive force from the motor to the intermediate portion as a torque about the primary central axis. In some embodiments, the drive axis extends through a centroid of first and second spaced apart cross-sectional planes of the tang, the first and second planes each being perpendicular to the primary central axis.

First claim

What is claimed is:

1. A surgical cutting tool for use in the dissection of bone, biomaterials, and/or other tissue when mated with a motor, the surgical tool comprising:
an elongated shaft defining opposing, first and second ends, a dissection portion adjacent the first end, a coupling portion adjacent the second end, and an intermediate portion between the dissection and coupling portions, the intermediate portion defining a primary central axis of the shaft;
wherein the coupling portion includes a tang having a tapered cylindrical shape that defines a drive axis, the tapered cylindrical shape defining a perimeter shape in a cross-sectional plane perpendicular to the primary central axis having first and second continuously curved segments combining to define at least 80% of a perimeter length of the perimeter shape;
and further wherein an arc length of the first continuously curved segment differs from an arc length of the second continuously curved segment;
and even further wherein the perimeter shape of at least one location along the tang consists solely of the first and second continuously curved segments, including the first and second continuously curved segments intersecting one another at opposing lines of intersection;
and even further wherein the drive axis is slanted with respect to the primary central axis.

2. The surgical cutting tool of claim 1 , wherein the tapered cylindrical shape is a non-symmetrical tapered cylindrical shape.

3. The surgical cutting tool of claim 1 , wherein the primary central axis and the drive axis form an oblique angle.

4. The surgical cutting tool of claim 1 , wherein a slant axis is defined at an intersection of the primary central axis and the drive axis, and further wherein the slant axis is in the range of 3-20 degrees.

5. The surgical cutting tool of claim 1 , wherein the drive axis extends through a centroid of a shape of the tang in first and second spaced apart transverse cross-sectional planes, the first and second transverse cross-sectional planes being perpendicular to the primary central axis.

6. The surgical cutting tool of claim 1 , wherein the arc lengths of the first and second continuously curved segments decrease in extension toward the second end.

7. The surgical cutting tool of claim 1 , wherein the first and second continuously curved segments are convex curves.

8. The surgical cutting tool of claim 1 , wherein a shape of the tang includes first and second partial cylinder regions.

9. The surgical cutting tool of claim 1 , wherein in the cross-sectional plane perpendicular to the primary central axis, the perimeter shape of the tang is non-flattened.

10. The surgical cutting tool of claim 1 , wherein a shape of the tang tapers in maximum outer dimension in extension to the second end.

11. The surgical cutting tool of claim 1 , wherein the coupling portion further includes an axial retention feature.

12. The surgical cutting tool of claim 11 , wherein the axial retention feature includes a circumferential groove between the tang and the intermediate portion.

13. The surgical cutting tool of claim 11 , wherein the axial retention feature includes a slot along the tang.

14. The surgical cutting tool of claim 1 , wherein the tang defines a tapering diameter in a direction of the second end and non-symmetric relative to the primary central axis.

15. The surgical cutting tool of claim 1 , wherein at least a majority of the intermediate portion is an elongated right cylinder defining the primary central axis.

16. A surgical system for cutting tissue, the system comprising:
a powered handpiece including:
a housing,
a drive shaft rotatably maintained by the housing,
a coupling assembly disposed within the housing and including a drive chuck connected to the drive shaft; and

a surgical cutting tool releasably connectable to the powered handpiece, the surgical cutting tool including:
an elongated shaft defining opposing, first and second ends, a dissection portion adjacent the first end, a coupling portion adjacent the second end, and an intermediate portion between the dissection and coupling portions, the intermediate portion defining a primary central axis of the shaft;
wherein the coupling portion includes a tang having a tapered cylindrical shape that defines a drive axis, the tapered cylindrical shape defining a perimeter shape in a cross-sectional plane perpendicular to the primary central axis having two continuously curved segments combining to define at least 80% of a perimeter length of the perimeter shape;
and further wherein in the cross-sectional plane perpendicular to the primary central axis, an entirety of the perimeter shape of the tang is non-flattened;
and even further wherein the drive axis is slanted with respect to the primary central axis;

wherein the system is configured such that upon insertion of the tang into the drive chuck and rotation of the drive chuck, a drive force applied to the tang is transmitted as a torque to the intermediate portion about the primary central axis.

17. The surgical system of claim 16 , wherein the powered handpiece is configured such that the drive chuck is rotatably driven about an axis of rotation aligned with the primary central axis.

18. The surgical system of claim 17 , wherein rotation of the drive chuck imparts a shear force on to the tang.

19. A surgical cutting tool for use in the dissection of bone, biomaterials, and/or other tissue when mated with a motor, the surgical tool comprising:
an elongated shaft defining opposing, first and second ends, a dissection portion adjacent the first end, a coupling portion adjacent the second end, and an intermediate portion between the dissection and coupling portions, the intermediate portion defining a primary central axis of the shaft;
wherein the coupling portion includes a tang having a tapered cylindrical shape that defines a drive axis;
wherein the coupling portion further includes an axial retention feature including a circumferential groove between the tang and the intermediate portion;
and further wherein the drive axis is slanted with respect to the primary central axis.

Assignees

• Medtronic Ps Medical Inc

Inventors

• Dexter S Shane
• Heiliger Zachary

Classifications

• A61B17/3205 Primary

  Excision instruments · CPC title

• A61B17/162 Primary

  Chucks or tool parts which are to be held in a chuck · CPC title