Rotary oscillating/reciprocating surgical tool
Inventors
Bono, Peter L • Lark, James D. • Scales, John S.
Assignees
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Publication Number
US-12446911-B2
Publication Date
2025-10-21
Expiration Date
Abstract
A surgical tool that has a pair of transmissions coupled to one another to effect driving of a cutting tool in both an oscillating manner and a reciprocating manner. The transmissions are driven by a motor coupled to one of the transmissions.
Core Innovation
The disclosure describes a powered surgical tissue-removal tool that modifies hard tissue using a rotary oscillating cutter driven by two coordinated transmissions. A motor drives a first driver to effect oscillating rotary motion of a cutter support shaft, and a second driver derives longitudinal reciprocating motion of the cutter shaft from the oscillation while the cutter shaft is oscillating, so that reciprocation occurs simultaneously with oscillation.
The transmission implementation is based on a curved gear rack that oscillates along a curved path during motor operation, and a crank assembly and follower assembly that oscillate the curved gear rack. A gear mounted to the cutter shaft is meshed with the curved gear rack to effect oscillating rotation of the cutter shaft. The document also describes a helical bearing associated with the cutter shaft that is operable to effect the reciprocation of the cutter shaft in response to rotary oscillation of the cutter shaft.
The disclosure further emphasizes limiting the oscillation angular range to about 90° to about 180° to reduce damage to fibrous tissue. Multiple mechanical implementations of the drivers are described, including rack-and-gear path arrangements using Cardan-type mechanisms, curved rack with crank and follower arrangements, and reciprocation arrangements using joint or wobble plate geometry or helical bearing/ball-screw mechanisms. Tool configurations include a handheld housing with a precision grip and optional mounting to a multi-axis surgical robot, with possible motor power sources such as cord electricity with a motor or compressed air/vacuum motor power.
Claims Coverage
The document provides two independent claims that share a common architecture: a handle-mounted motor drives a transmission with a first driver to provide rotary oscillation and a second driver to provide reciprocating motion of a cutter shaft while the shaft is oscillating. Across the dependent claims, additional inventive features include a curved gear rack oscillating along a curved path, crank and follower assemblies oscillating the curved gear rack, meshing between the curved gear rack and a gear on the cutter shaft, and a helical bearing for reciprocation responsive to rotary oscillation, as well as an angular displacement constraint and specific helical bearing structure and mounting constraints.
Curved gear rack with oscillating curved path
The first driver includes a curved gear rack which oscillates along a curved path during operation of the motor.
Crank and follower oscillate curved gear rack
The first driver includes a crank assembly coupled to the motor and a follower assembly operably associated with the crank assembly for oscillating the curved gear rack.
Gear meshed with curved gear rack drives cutter shaft oscillation
The second driver includes a gear mounted to the cutter shaft and meshed with the curved gear rack to effect oscillating rotation of the cutter shaft.
Helical bearing converts rotary oscillation to reciprocation
The second driver includes a helical bearing associated with the cutter shaft and operable to effect the reciprocation of the cutter shaft in response to rotary oscillation of the cutter shaft effected by the first driver.
Curved-path-driven simultaneous reciprocation while oscillating
A transmission operably coupled to the motor has a first driver and a second driver, the second driver being coupled to the first driver to simultaneously effect reciprocating motion of the cutter shaft while the cutter shaft is oscillating.
Angular displacement less than 180 degrees
The angular displacement of rotation of the cutter shaft and cutter is less than 180 degrees.
Helical bearing structure with inner race, outer race, and bearing balls
A helical bearing with an inner race, an outer race, and a plurality of bearing balls retained between the races.
Outer race fixed against movement relative to the handle
The outer race is fixed against movement relative to the handle.
Pneumatic motor implementation
The motor is a pneumatic motor.
Handle configured for mounting to a surgical robot
The handle is configured to be mounted to a surgical robot.
Overall, the claim coverage centers on a surgical tool having a rotary oscillating cutter in which motor-driven transmission architecture uses a curved gear rack oscillated by a crank and follower to drive oscillating rotation of a cutter shaft, while a helical bearing effects reciprocation in response to that rotary oscillation. The dependent claims further constrain motion to less than 180 degrees and specify aspects of helical bearing structure, outer race mounting relative to the handle, optional pneumatic motor implementation, and optional robot mounting of the handle.
Stated Advantages
Reduces damage to fibrous tissue by limiting the oscillation angular range to about 90° to about 180°.
Documented Applications
No documented applications found
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