Flexible Cannulated Cutting Device for Spinal Drilling
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Solution Overview
Problem
Existing drilling devices are unable to effectively drill and mill the intervertebral space between two vertebrae by passing through the pedicles, as they lack control over the radius of curvature and cannot guarantee the drilling point, especially in spinal segments.
Innovation Solution
A flexible and cannulated cutting device with a cutting element comprising a rigid tube, a flexible connection of helical fibers or threads, and a guide element made of Nitinol, allowing for angular deformation and positioning within bone or connective tissue, equipped with a cannulated cutter and a safety connector for torque-controlled uncoupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid drilling device is used, then the drilling strength and structural stability are improved, but the ability to drill in curved directions and access intervertebral spaces is worsened
Solution Approach 1:
The drilling device is divided into a rigid cutting element portion and a flexible connection portion. The rigid tube (20) provides structural strength for cutting, while the flexible connection (21) with helical fibers allows curvature. This segmentation enables the device to maintain drilling strength while gaining adaptability to curved paths for accessing intervertebral spaces.
Solution Approach 2:
The flexible connection comprises a composite structure with helical fibers or wires arranged in layers, providing both flexibility for curved drilling and sufficient torsional strength. The composite construction allows the device to bend along a radius of curvature while maintaining the strength needed for effective bone cutting.
2Adaptability or versatility
If a flexible drilling device is used, then the ability to drill in curved directions is improved, but the control over radius of curvature and drilling point precision is worsened
Solution Approach 1:
A guide element is provided that defines the desired curved path and radius of curvature before drilling begins. The flexible connection is designed to conform to this predetermined guide, ensuring that the drilling point follows the intended trajectory with precise control, eliminating the uncertainty associated with purely flexible devices.
Solution Approach 2:
The guide element acts as an intermediary between the operator's intent and the flexible cutting element's motion. It mediates the curvature control by providing a physical template that the flexible connection follows, thereby maintaining precision in the drilling point location while enabling curved path drilling.
3Stability of the object's composition
If the cutting device is made rigid for stable operation, then the structural stability is improved, but the ability to deform angularly within bone tissue is worsened
Solution Approach 1:
The device is segmented into a rigid cutting element for stable cutting operation and a flexible connection portion that can deform angularly. The rigid tube (20) maintains structural stability during cutting, while the flexible connection (21) with its helical fiber construction allows the necessary angular deformation to navigate curved paths within bone tissue.
Solution Approach 2:
The flexible connection comprises a structure with helical fibers or wires that can deform angularly while maintaining structural integrity. This flexible yet strength-retaining construction allows the cutting device to adapt its angle within bone tissue without compromising the stability needed for effective cutting.
4Productivity
If a solid cutting element is used, then the cutting efficiency is improved, but the compressive stresses transmitted to the connection are worsened
Solution Approach 1:
The flexible connection is designed with a hollow or porous-like structure formed by the helical fiber arrangement, which reduces the transmission of compressive stresses from the solid cutting element. This structure allows the connection to absorb and distribute stresses, protecting the flexible portion from excessive compression while maintaining cutting efficiency.
Solution Approach 2:
The composite construction of the flexible connection with multiple layers of helical fibers provides stress distribution capabilities. The layered composite structure reduces peak compressive stresses on the connection by distributing loads across multiple fibers and layers, enabling efficient cutting without overloading the flexible connection portion.
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
Enables precise drilling and milling in curved directions within bone or connective tissue, reducing compressive stresses and ensuring safe operation by controlled torque uncoupling, thereby facilitating access to intervertebral spaces.
Implementation Method 1
a hollow strand which is made up of an arrangement of at least three layers of helical fibers or wires arranged in a staggered pattern
Implementation Method 2
a guide element ensuring the positioning and angular deformation of the cutting element inside the bone or connective tissue
Implementation Method 3
a guide element made of Nitinol
Implementation Method 4
a cannulated cutter with at least three teeth regularly distributed around an internal bore and whose cutting profile respectively ensures a swallowing of material causing during the rotation drive of said cutting device its advancement in bone or connective tissues
Data Source
Figure 1
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AI summary
The flexible and cannulated cutting device (1) for boring and/or drilling a space in bone or connective tissue comprises a cutting element (2) consisting of a rigid tube (20) secured, at one of its ends, to a flexible coupling (21) extended by a cannulated drilling member (22), and, at the opposite end, to drive means provided with a safety connector (23) for releasing said cutting device; and a guide element (3) for positioning and deforming at an angle the cutting element (2) inside the bone or connective tissue.