Apparatus And Method For A High Speed Rotation-To-Rotation Oscillation Converter For Surgical Use

• US 20080234716A1
• Filed: 09/29/2006
• Published: 09/25/2008
• Est. Priority Date: 10/12/2005
• Status: Active Grant

• Current Assignee: Douglas P. Kiester
• Original Assignee: Douglas P. Kiester
• Inventors: Kiester, Douglas P.
• Granted Patent: US 8,006,578 B2
• Time in Patent Office: Days
• US Class Current: 606/171
• CPC Class Codes: A61B 17/1624 Drive mechanisms therefor
• CPC Class Codes: Y10T 74/1804 Rotary to reciprocating and alternating rotary

Abstract

A converter for use in a high speed rotationally oscillating surgical burring device comprises an output shaft, and a rotationally oscillating secondary drive rotor coupled to the output shaft. The secondary drive rotor is arranged and configured with a size and mass to minimize its angular momentum. A unidirectionally rotating primary drive rotor is provided. A linearly reciprocating transmission converts unidirectional rotation to bidirectional rotational oscillation coupling the primary and secondary drive rotors. The transmission is arranged and configured with a size and mass to minimize its linear momentum. An input shaft is coupled to the rotating primary drive rotor to which a unidirectional rotational force is applied.

Claims

1. A converter for use in a high speed rotationally oscillating surgical burring device comprising:

an output shaft;

a rotationally oscillating secondary drive rotor coupled to the output shaft, the secondary drive rotor being arranged and configured with a size and mass to minimize its angular momentum;

an unidirectionally rotating primary drive rotor;

a linearly reciprocating transmission for converting unidirectional rotation to bidirectional rotational oscillation coupling the primary and secondary drive rotors, the transmission being arranged and configured with a size and mass to minimize its linear momentum; and

an input shaft coupled to the rotating primary drive rotor to which a unidirectional rotational force is applied.

2. The converter of claim 1 where the output shaft has a longitudinal axis of rotation and where the transmission has its minimized linear momentum aligned with the longitudinal axis of rotation of the output shaft.

3. The converter of claim 2 where the transmission has its minimized linear momentum is only along the longitudinal axis of rotation of the output shaft.

4. The converter of claim 1 where the output shaft, the secondary drive rotor, the primary drive rotor, the transmission and the input shaft are operable in both forward and reverse senses.

5. The converter of claim 1 further comprising means for preventing full rotation of the secondary drive rotor in event of failure.

6. The converter of claim 1 where the output shaft, the secondary drive rotor, the primary drive rotor, the transmission and the input shaft each have a degree of azimuthal symmetry and are each mutually coaxial with each other.

7. The converter of claim 1 where the output shaft, the secondary drive rotor, the primary drive rotor, the transmission and the input shaft are arranged and configured to be capable of operating at a speed such that the output shaft oscillates at 60 kHz or greater.

8. The converter of claim 1 where the secondary drive rotor has a spiral slot defined therethrough, and where the transmission comprises a drive pin disposed through the spiral slot, so that the secondary drive rotor rotationally oscillates as the drive pin longitudinally reciprocates.

9. The converter of claim 8 where the transmission further comprises a stationary guide having a linear slot defined therethrough through which the drive pin is disposed to maintain the drive pin in a fixed plane of oscillatory linear motion.

10. The converter of claim 9 where the transmission further comprises a cam follower coupled to the drive pin, where the primary drive rotor has a cylindrical bore in which an elliptical groove is defined, the cam follower engaging the elliptical groove so that the drive pin is longitudinally reciprocated within the primary drive rotor as the primary drive rotor unidirectionally rotates.

11. The converter of claim 9 where the drive pin has two opposing ends and where the transmission further comprises a pair of cam followers, one cam follower coupled to each end of the drive pin, and where a pair of elliptical intersecting grooves are defined in the cylindrical bore, each cam follower engaging one of the pair of elliptical grooves so that the drive pin is longitudinally reciprocated within the primary drive rotor as the primary drive rotor unidirectionally rotates.

12. The converter of claim 10 where the elliptical groove and spiral slot are arranged and configured in the primary and secondary rotors respectively to provide a minimal linear velocity of the drive pin when the drive pin is near or at the ends of the spiral groove in the secondary rotor.

13. The converter of claim 1 further comprising a safety piece to disengage the secondary rotor from the primary rotor in the event of malfunction causing full rotation of the secondary rotor with the primary rotor.

14. A converter for use in a high speed oscillating surgical burring device comprising:

an output shaft;

a secondary drive rotor coupled to the output shaft, the secondary drive rotor having a spiral slot defined therethrough and being arranged and configured with a size and mass to minimize its angular momentum;

a drive pin being disposed through the spiral slot, so that the secondary drive rotor rotationally oscillates as the drive pin longitudinally reciprocates;

a stationary guide having a linear slot defined therethrough through which the drive pin is disposed to maintain the drive pin in a fixed plane of oscillatory linear motion; and

a cam follower coupled to the drive pin;

a primary drive rotor having a cylindrical bore;

a pair of elliptical intersecting grooves defined in the cylindrical bore, the cam follower engaging the pair of elliptical grooves so that the drive pin is longitudinally reciprocated within the primary drive rotor as the primary drive rotor unidirectionally rotates; and

an input shaft coupled to the primary drive rotor and to which input shaft a unidirectional rotational force is applied.

15. A method of providing oscillating rotational motion to surgical burring device comprising:

unidirectionally rotating an input shaft;

unidirectionally rotating a primary drive rotor by the input shaft;

transforming the unidirectional rotation of the primary drive rotor into linearly reciprocating motion of a reciprocating component which is arranged and configured with a size and mass to minimize its linear momentum;

transforming the linearly reciprocating motion of the reciprocating component into bidirectional rotational oscillation of a secondary drive rotor, which is arranged and configured with a size and mass to minimize its angular momentum; and

rotationally oscillating an output shaft coupled to the secondary drive rotor.

16. The method of claim 15 where the output shaft has a longitudinal axis of rotation and where transforming the unidirectional rotation of the primary drive rotor into linearly reciprocating motion of a reciprocating component comprises generating linearly reciprocating motion of a reciprocating component along a direction of the longitudinal axis of rotation of the output shaft.

17. The method of claim 16 where generating linearly reciprocating motion of a reciprocating component along a direction of the longitudinal axis of rotation of the output shaft comprises generating linearly reciprocating motion only along the longitudinal axis of rotation of the output shaft.

18. The method of claim 15 further comprising rotating the input shaft, rotating the primary drive rotor, transforming the unidirectional rotation of the primary drive rotor into linearly reciprocating motion of a reciprocating component, transforming the linearly reciprocating motion of the reciprocating component into bidirectional rotational oscillation of the secondary drive rotor, and rotationally oscillating the output shaft in both forward and reverse senses.

19. The method of claim 15 further comprising preventing full rotation of the secondary drive rotor in event of failure.

20. The method of claim 15 further comprising rotating the input shaft, rotating the primary drive rotor, linearly reciprocating the reciprocating component, bidirectional rotational oscillating the secondary drive rotor, and rotationally oscillating the output shaft comprises performing each motion mutually coaxially with each other.

21. The method of claim 15 where rotating the input shaft, rotating the primary drive rotor, transforming the unidirectional rotation of the primary drive rotor into linearly reciprocating motion of a reciprocating component, transforming the linearly reciprocating motion of the reciprocating component into bidirectional rotational oscillation of the secondary drive rotor, and rotationally oscillating the output shaft operate at a speed so that the output shaft oscillates at 60 kHz or greater.