Motorized Cable Bone Transport for Precise External Fixation
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Solution Overview
Problem
Manual adjustment of struts in external fixation devices for bone manipulation is painful, difficult, and prone to errors, leading to complications in procedures like fracture repair and deformity correction.
Innovation Solution
A bone transport device with automated actuator assemblies and a controller to adjust the position of bone segments using a cable and spools, allowing for precise and pain-free manipulation of bone segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual adjustment of struts is used in external fixation devices, then the device structure remains simple, but the adjustment process becomes painful, difficult, and prone to errors
Solution Approach 1:
The patent replaces the manual mechanical adjustment system with an automated actuation system. The actuator assembly includes a motor that rotates a spool to wind or unwind a cable, which in turn moves the strut. This substitution of manual mechanical operation with an automated motorized system resolves the contradiction by providing easy, pain-free adjustment while accepting increased device complexity.
Solution Approach 2:
The actuator assembly enables the device to adjust itself without requiring manual intervention by the patient. The motorized system automatically performs the strut adjustment based on control signals, making the adjustment process self-service oriented. This eliminates the painful and difficult manual adjustment process while maintaining a relatively simple overall device structure.
2Productivity
If manual strut adjustment is performed multiple times daily, then bone manipulation can be achieved, but patient compliance becomes difficult and complications increase
Solution Approach 1:
The patent replaces repeated manual adjustment operations with an automated actuator system that can be controlled multiple times daily through electronic control. The motorized actuator can be activated numerous times without requiring manual patient intervention, thereby maintaining high productivity in terms of adjustment frequency while significantly improving reliability through automated precision control and eliminating compliance issues.
Solution Approach 2:
The actuator assembly incorporates control mechanisms that enable precise and repeatable adjustments. The system can be controlled to perform adjustments at specific intervals and with specific parameters, ensuring consistent and reliable bone manipulation. This feedback-controlled automated system maintains high adjustment frequency while ensuring reliability through precise control and monitoring.
3Measurement precision
If automated actuator assemblies are implemented, then adjustment precision and pain-free operation are achieved, but device complexity increases
Solution Approach 1:
The patent implements a motorized actuator assembly that replaces manual adjustment mechanisms. The motor provides precise control over the spool rotation, which in turn precisely controls cable winding and strut movement. This substitution achieves high adjustment precision through electronic control while the complexity is contained within the modular actuator assembly, making the overall device manageable.
Solution Approach 2:
The actuator assembly is designed as a separate, modular unit that can be independently attached to the external fixation device. This segmentation allows the complex actuation mechanism to be isolated and managed as a distinct component, reducing the perceived overall complexity while maintaining high precision in the adjustment function.
Data Source
AI summary
A bone transport device may include a first support member, a second support member, a plurality of first rods, a cable, and a plurality of actuator assemblies. The cable may be configured to be received through a first bone segment. The bone transport device may further include a second rod that is configured to extend through the first bone segment such that the cable abuts a portion of the second rod within the first bone segment. The plurality of actuator assemblies may be attached to the first support member or the second support member. Each of the plurality of actuator assemblies may include a body, a spool, and an actuator. The actuator may be configured to rotate the spool to wind the cable onto the spool and translate a second bone segment with respect to the first support member and the second support member.