Strap Drive Train for Robotic Surgical Arms
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Solution Overview
Problem
Traditional robotic surgical arms rely on expensive metal control cables, which complicate maintenance and increase costs, while also limiting the range of motion necessary for various surgical procedures.
Innovation Solution
The implementation of a multi-layer or multi-ply strap drive train system in robotic surgical arms, which replaces traditional cables with straps and pulleys, enhancing the range of motion and reducing manufacturing and maintenance costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional metal control cables are used in robotic surgical arms, then the structure is simple and easy to implement, but the manufacturing cost and maintenance cost increase, and the range of motion is limited
Solution Approach 1:
The patent segments the control cable system into multiple independent straps, each responsible for specific motion control. This segmentation allows the robotic arm to achieve greater range of motion while maintaining manageable system complexity through modular design
Solution Approach 2:
The patent introduces an additional dimensional aspect by using multiple straps arranged in different spatial orientations and layers. This multi-dimensional strap arrangement enables control of complex multi-axis movements that cannot be achieved with traditional single-cable systems
2Ease of manufacture
If traditional metal control cables are used in robotic surgical arms, then the implementation is straightforward, but the manufacturing cost and maintenance cost increase
Solution Approach 1:
The patent employs straps made from cost-effective materials such as Kevlar® or other high-strength synthetic fibers, which are less expensive than traditional metal control cables. These straps are designed to be replaceable components that can be easily manufactured and installed, reducing both initial manufacturing costs and long-term maintenance expenses
Solution Approach 2:
The patent changes the material parameters from metal to high-strength synthetic materials, altering the cost, weight, and flexibility characteristics. This parameter change enables cost-effective manufacturing while maintaining the necessary mechanical performance for surgical applications
3Adaptability or versatility
If multi-layer or multi-ply strap drive train system is implemented, then the range of motion is improved and costs are reduced, but the strap routing and tensioning complexity increases
Solution Approach 1:
The patent implements a nested strap configuration where multiple straps are routed through each other and around shared pulleys in a hierarchical arrangement. This nesting strategy organizes the complex multi-strap system in a compact, systematic manner that simplifies routing while enabling control of multiple degrees of freedom
Solution Approach 2:
The patent designs pulleys and routing mechanisms that serve multiple functions simultaneously - guiding multiple straps, maintaining tension, and enabling range of motion control. This multi-functionality reduces the number of separate components needed, thereby simplifying the overall routing complexity despite the increased number of straps
4Strength
If multi-layer or multi-ply strap drive train system is implemented, then the stiffness and strength are improved, but the manufacturing complexity increases
Solution Approach 1:
The patent utilizes composite material construction for the straps, combining multiple layers or plies of high-strength materials such as Kevlar® or carbon fiber. This composite approach achieves superior strength and stiffness characteristics while using commercially available material layers that can be manufactured through standard composite fabrication processes
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 strap drive train system improves the range of motion for robotic surgical arms, reduces maintenance complexity, and lowers costs by using durable, multi-ply straps that provide high stiffness and strength, while minimizing vibrations and deflections.
Implementation Method 1
a pulley disposed at an idler pulley location to redirect the strap to track onto the idler pulley
Implementation Method 2
a strap guide bearing disposed at a strap guide location between the strap and the pulley to guide the strap onto the idler pulley
Data Source
AI summary
In one embodiment of the invention, a robotic arm is provided including a linkage assembly and a strap drive train. The linkage assembly includes first, second, third, and fourth links pivotally coupled in series together at first, second, and third joints to define a parallelogram with an insertion axis. The strap drive train includes first and second sets of straps coupled to the linkage assembly. As the linkage assembly is moved about a pitch axis, the first set of straps ensures the third link maintains the same angle relative to the first link, and the first and second set of straps ensures the fourth link maintains the same angle relative to the second link.