Surgical Bur Push-Off Elements Deflect Tool Chatter

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Solution Overview

Problem

Existing surgical burs struggle with uncontrolled vibration, known as 'tool chatter,' which affects cutting performance and requires manual adjustment, making surgical procedures inefficient and tedious for surgeons.

Innovation Solution

A surgical bur design featuring a stem with a plurality of cutting flutes and push-off elements between them, which deflects the bur relative to the bone, optimizing cutting efficiency and effectiveness based on speed and angle of rotation or oscillation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an aggressive cutting flute is designed to improve cutting efficiency, then cutting efficiency is improved, but vibration control deteriorates

Engineering Contradiction:
Improvecutting efficiencyVSAvoidvibration control
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The cutting flute is segmented into multiple sections along the longitudinal axis, with each section having different geometric characteristics. The distal section has a first geometry optimized for cutting efficiency, while the proximal section has a second geometry designed to control vibration. This segmentation allows the single flute to simultaneously achieve both aggressive cutting and vibration control without requiring separate components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the cutting flute are assigned different local qualities or geometric properties. The distal portion features a more aggressive geometry for efficient bone cutting, while the proximal portion features a modified geometry with specific helix angles and cross-sectional shapes that provide vibration damping. This local differentiation resolves the contradiction by optimizing each region for its specific function.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If manual adjustment of dampening mechanisms is performed to control tool chatter, then vibration control is improved, but device complexity and ease of operation worsen

Engineering Contradiction:
Improvetool chatter controlVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The cutting flute's geometry itself provides the vibration control function without requiring separate adjustable dampening mechanisms. The specific helix angles, cross-sectional shapes, and longitudinal variations in the flute geometry create inherent vibration damping characteristics. This self-service approach eliminates complex adjustment mechanisms while maintaining effective tool chatter control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The design converts the potential harm of vibration into a beneficial controlled oscillation pattern. By carefully designing the flute geometry, the natural vibrations are channeled and dampened in a controlled manner that actually enhances cutting performance. The vibration that would normally be harmful is transformed into a useful feature through geometric design.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If manual tuning during surgical procedure is performed to optimize cutting, then cutting efficiency is improved, but loss of time increases

Engineering Contradiction:
Improvecutting efficiencyVSAvoidtuning time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The optimal geometric configuration is predetermined and built into the cutting flute during manufacturing. The helix angles, cross-sectional shapes, and longitudinal variations are pre-calculated and pre-formed to provide optimal cutting efficiency and vibration control for the intended application. This preliminary action eliminates the need for intraoperative tuning, saving surgical time while maintaining high cutting efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The design uses specific parameter values for the flute geometry (helix angles, cross-sectional dimensions, longitudinal spacing) that are optimized for high-speed rotation and efficient cutting. These parameters are selected during design to provide optimal performance at the intended operating conditions, eliminating the need for parameter adjustment during surgery.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The surgical bur self-regulates tool chatter, enhancing cutting efficiency and effectiveness by up to 2 to 3 times compared to prior art designs, reducing manual tuning requirements and improving surgical precision.

Implementation Method 1

The push-off elements are configured to deflect the surgical bur relative to the bone and optimize the cutting efficiency and effectiveness of the surgical bur based on the speed (RPM) of the surgical bur

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4545020A1Surgical bur with improved cutting and method of improving cutting effectiveness
Publication Date: 2025.04.30 MEDTRONIC PS MEDICAL INC
  • EP4545020A1 patent drawingFigure 1~1A
  • EP4545020A1 patent drawingFigure 2~3A
  • EP4545020A1 patent drawingFigure 3B~3C

AI summary

A surgical bur for use in cutting bone includes a stem adapted to selectively couple to an attachment tube of a micro-burring instrument assembly and is configured for selective rotation upon activation of the micro-burring instrument. The surgical bur includes a plurality of cutting flutes disposed at a distal end of the stem which defines a corresponding number of clearance surfaces disposed therebetween. Each of the cutting flutes includes a cutting edge and a trailing edge. One or more push-off elements is defined in the clearance surface between adjacent pairs of cutting flutes of the plurality of cutting flutes, the push-off elements being configured to contact bone during rotation of the surgical bur and being configured to deflect the surgical bur relative thereto and optimize the cutting efficiency and effectiveness of the surgical bur based on the rotational speed (RPM) thereof.