Curved Bur With Constraining Neck To Prevent Extrusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary abraders for arthroscopic surgery lack stability and proper access to curved anatomical structures due to excessive bending and bur wobble, and fail to prevent tip extrusion during rotation.
Innovation Solution
A curved bur design featuring a flexible inner coil with a spiral configuration and a constraining neck feature in the outer tube to center and secure the bur tip, preventing wobble and extrusion, while allowing for torque and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a straight bur is used to access curved anatomical structures, then access to the surgical site is achieved, but excessive bending occurs causing bur wobble and instability
Solution Approach 1:
The bur is designed with a curved configuration instead of a straight shape, allowing it to conform to curved anatomical structures such as the acetabulum, talus, glenoid, and notch. This curvature enables the bur to access difficult-to-reach areas while maintaining stability and preventing excessive bending during arthroscopic procedures.
2Adaptability or versatility
If the inner coil is made flexible to allow rotation, then torque and flexibility are provided, but the coil may stretch and the bur tip may extrude from the outer tube
Solution Approach 1:
The inner coil is constructed as a flexible spiral-wrapped structure that can bend and rotate while maintaining its structural integrity. The flexible nature of the coil allows it to accommodate torques and navigate curved paths, while the outer tube with its constraining neck feature prevents the coil from over-stretching and keeps the bur tip contained within the outer tube during rotation.
3Ease of operation
If the bur tip is allowed to move freely within the outer tube, then flexibility is maintained, but bur wobble and extrusion occur during rotation
Solution Approach 1:
The inner flexible coil assembly is nested within the outer rigid tube structure. The outer tube provides a constraining environment that centers and stabilizes the inner coil, preventing bur wobble and tip extrusion during rotation. This nested configuration allows the inner coil to maintain flexibility while being stabilized by the outer tube's constraining features.
4Volume of moving object
If a compact size is used to fit through small cannulae, then access through small openings is achieved, but the bur may become too flexible and unstable
Solution Approach 1:
The bur is divided into distinct segments: an inner flexible coil assembly and an outer rigid tube structure. This segmentation allows the inner coil to provide flexibility for navigating curved paths and fitting through small cannulae, while the outer tube provides structural stability and prevents excessive bending. The combined structure achieves both compact size and stability.
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 solution enhances stability and containment of the bur tip within the outer tube, preventing extrusion and wobble, thereby improving access to curved anatomical structures during arthroscopic procedures.
Implementation Method 1
an inner flexible member that is rotatably positioned within an outer tube and that consists of a spiral wrapped coil to provide torque and flexibility
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 3A~3B
AI summary
A curved bur (100,100a,100b,200) with an inner flexible member (80) that is rotatably positioned within an outer tube (52). The curved bur has a design that constrains the flexible inner coil (85) within the outer tube as the curved bur is rotated (without permitting the coil to stretch and to allow the bur tip to come out of the distal end of the outer tube). To ensure containment of the flexible coil within the outer tube, the outer tube is provided with a constraining neck feature (88,155) at its distal end to allow the flexible inner assembly (80) to be constrained within the outer tube, and to prevent bur extrusion. The constraining neck feature also centers the bur tip (116) and prevents bur wobble. The curved bur may have a convex or concave bend configuration.