Surgical Bur Geometry to Prevent Drift and Protect Soft Tissue
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Solution Overview
Problem
Surgical burs currently lack the necessary control and geometry to prevent damage to sensitive soft tissue structures like the dura mater during bone cutting procedures, leading to increased risks of infections and surgical complications.
Innovation Solution
The design of a surgical bur with a body featuring flutes and lands, including axial relief surfaces with specific angles and shapes that minimize contact with the dura mater, allowing for efficient bone cutting while gliding over soft tissue without engagement or tearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If surgical burs use traditional geometries for efficient bone cutting, then cutting efficiency is improved, but control and stability deteriorate leading to drifting into soft tissue
Solution Approach 1:
The patent applies parameter changes by modifying the bur geometry parameters including drill point angle (90-110 degrees), axial relief angle (5-15 degrees), and flute configuration. These parameter adjustments optimize the balance between bone cutting efficiency and control stability, preventing the bur from drifting into soft tissue while maintaining effective bone dissection capability
2Productivity
If surgical burs have aggressive cutting geometries, then bone cutting performance is improved, but risk of soft tissue damage increases
Solution Approach 1:
The patent applies local quality by creating distinct functional zones on the bur surface: cutting edges with specific angles for bone engagement, axial relief surfaces (5-15 degrees) that prevent soft tissue adherence, and flute configurations that control chip evacuation. This localized differentiation ensures aggressive cutting where needed while providing protective characteristics in contact zones with soft tissue
Solution Approach 2:
The patent inverts the traditional approach by designing axial relief surfaces that angle away from the cutting direction (5-15 degrees). Instead of having the bur geometry naturally tend to engage soft tissue, the inverted relief angle causes the bur to glide over soft tissue structures like dura mater, preventing tearing and damage while maintaining effective bone cutting
3Ease of manufacture
If surgical burs use standard drill point angles, then manufacturing is simplified, but control and precision deteriorate
Solution Approach 1:
The patent modifies the drill point angle parameter from traditional values to an optimized range of 90-110 degrees. This parameter change improves control and precision by reducing bur drifting while maintaining manufacturability through standard grinding and fabrication processes. The axial relief angle parameter (5-15 degrees) is also optimized to enhance precision without significantly complicating manufacturing
Data Source
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AI summary
A surgical bur comprising a body (176), wherein the body comprises a plurality of flutes (180), wherein each of the plurality of flutes comprises a cutting edge (186), a rake face (184), and a clearance surface (188), and a plurality of lands (178), each of the plurality of lands is disposed between a pair of the plurality of flutes; and a drill point (194) comprising a plurality of axial relief surfaces (198), wherein each of the plurality of axial relief surfaces is distinct from the plurality of lands and borders (i) a distal portion of one of the cutting edges, (ii) one of the plurality of lands, and (iii) one of the clearance surfaces, wherein a proximal most edge of each of the plurality of axial relief surfaces borders a distal most edge of a respective one of the plurality of lands.