Flexible Tool Drive Shaft Assembly for Confined Surgical Access
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Solution Overview
Problem
Existing tool drive assemblies with rigid linear shafts face challenges in accessing limited surgical sites due to obstruction by soft tissue or bone, making it difficult to reach the desired location for driving fasteners or bone screws.
Innovation Solution
A tool drive assembly comprising a flexible drive shaft and a guide, where the flexible drive shaft is made of wound wires in alternating directions covered by a flexible sleeve, and the guide includes a handle, a guide shaft, and a hub assembly with a bearing for smooth rotation, allowing the distal end of the flexible drive shaft to be steered into tight areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a rigid linear shaft is used to drive fasteners or bone screws, then the structure is simple and stable, but it cannot reach the desired location due to obstruction by soft tissue or bone in limited surgical sites
Solution Approach 1:
The patent applies a flexible shaft construction with multiple wire layers wound in alternating directions, allowing the shaft to bend and navigate around obstructions in the surgical site while maintaining structural integrity for torque transmission
Solution Approach 2:
The shaft is segmented into multiple flexible wire layers that can independently bend and flex, enabling the shaft to conform to complex anatomical pathways while remaining transmissible of rotational force
2Ease of operation
If a rigid linear shaft is used, then the manufacturing is simple, but it cannot be steered into tight areas
Solution Approach 1:
The flexible shaft with its multi-layer wire construction and flexible sleeve provides steerability by allowing the distal end to be manually positioned and oriented, while the alternating wire windings maintain sufficient torsional rigidity for controlled operation
Solution Approach 2:
The shaft transitions from a static rigid structure to a dynamic flexible structure that can be manually manipulated into various configurations, allowing the operator to steer the distal end around obstructions while maintaining connection to the driving mechanism
3Adaptability or versatility
If a flexible drive shaft is used to access limited surgical sites, then accessibility is improved, but the structure becomes more complex
Solution Approach 1:
The flexible shaft is constructed with multiple layers of wires wound in alternating directions and covered by a flexible sleeve, creating a structure that is flexible enough to navigate confined spaces but maintains sufficient structural integrity for torque transmission
Solution Approach 2:
The shaft combines multiple materials and structural elements (wires, flexible sleeve, hub assembly with bearing) to achieve both flexibility for navigation and rigidity for mechanical drive function, resolving the contradiction between adaptability and structural simplicity
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 flexible drive shaft and guide assembly enable effective manipulation and positioning of working tools in confined surgical spaces, overcoming the limitations of rigid shafts and improving access and maneuverability.
Implementation Method 1
a bearing between the hub and the housing for rotation of the hub relative to the housing
Data Source
AI summary
A tool drive assembly including a flexible drive shaft and a guide. The flexible drive shaft includes a proximal end structured to engage a driver for rotating the flexible drive shaft, and a distal end opposite the proximal end. The guide includes a handle, a shaft extending from the handle, and a hub assembly at a distal end of the shaft. The hub assembly includes a housing, and a hub rotatably mounted within the housing. The hub includes an input connection structured to attach to the distal end of the flexible drive shaft, and an output connection structured to attach to a working tool. The tool drive assembly enables easy manipulation and driving of a working tool to achieve optimum positioning and effectiveness of the working tool.