Surgical Bur Rake Surface Segmentation for Stable Axial Drilling

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Solution Overview

Problem

Existing surgical burs lack stability during axial drilling and efficient cutting during radial movement, which can lead to inefficiencies and potential damage to surrounding soft tissue structures during surgical procedures.

Innovation Solution

The surgical bur design incorporates flutes with decoupled rake surfaces, featuring a combination of negative axial rake angles for stability and positive radial rake angles for enhanced cutting efficiency, allowing for efficient bone cutting and shaping while minimizing contact with sensitive tissues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single rake surface with uniform angle is used, then the structure is simple, but drilling stability and cutting efficiency cannot be simultaneously optimized

Engineering Contradiction:

Improvecutting efficiencyVSAvoidrake surface structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The single rake surface is segmented into multiple distinct rake surfaces (first rake surface with first rake angle, second rake surface with second rake angle) along the flute. This segmentation allows different portions of the cutting edge to have different rake angles optimized for different functions: one portion for axial drilling stability and another for radial cutting efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different rake surfaces are assigned different rake angles based on their specific functional requirements. The first rake surface has a rake angle optimized for axial drilling stability, while the second rake surface has a rake angle optimized for radial cutting efficiency. This local differentiation of properties resolves the contradiction between drilling stability and cutting efficiency.

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If a single rake angle is used for the entire flute, then manufacturing is simple, but both axial drilling stability and radial cutting efficiency cannot be achieved

Engineering Contradiction:

Improvedrilling stabilityVSAvoidrake angle configuration

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The uniform rake angle is segmented into multiple discrete rake angles associated with different rake surfaces on the same flute. This allows the first rake surface to provide stability during axial drilling while the second rake surface enables efficient radial cutting, without requiring multiple separate flutes or complex multi-component structures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the flute are assigned different rake angles according to their specific operational requirements. The local quality variation in rake angles allows each segment to perform its specialized function optimally while maintaining overall structural simplicity.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3858265B1Surgical burs with decoupled rake surfaces and corresponding axial and radial rake angles

Publication Date: 2025.02.12 MEDTRONIC PS MEDICAL INC

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AI summary

A surgical bur (254) including flutes (260) and lands (258). Each of the flutes includes a cutting edge (266), rake surfaces (264.265) and a clearance surface (267). The rake surfaces of one of the flutes are decoupled from each other. Each of the lands is disposed between a pair of the flutes.