Jaw Actuation Mechanism for Single-Tendon Bidirectional Control
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Solution Overview
Problem
Existing surgical instruments with tendon-driven end effectors require multiple antagonistic tendons for actuation, leading to complexity, size constraints, and increased manufacturing costs due to numerous moving parts.
Innovation Solution
An actuation mechanism using a single tendon with two antagonistic portions to simultaneously rotate two jaw members in opposite directions, reducing the number of required tendons and moving parts, and incorporating a pulley to minimize friction and enhance durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple antagonistic tendons are used for actuation, then reliable bidirectional jaw movement is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple tendon functions into a single tendon system. One tendon controls both jaws simultaneously, eliminating the need for separate antagonistic tendon pairs for each jaw. This merging reduces the number of moving parts while maintaining reliable bidirectional movement through the coordinated action of the single tendon on both jaws.
Solution Approach 2:
The single tendon performs multiple functions: it actuates both the first jaw and the second jaw, providing bidirectional control for both components. This multi-functional approach replaces what would traditionally require multiple specialized tendons, reducing overall system complexity while maintaining full actuation capability.
2Ease of operation
If multiple antagonistic tendons are used for actuation, then complete control over jaw articulation is achieved, but the size of the end effector increases
Solution Approach 1:
By merging multiple tendon control lines into a single tendon that actuates both jaws, the patent reduces the space required for tendon routing and associated hardware. This consolidation maintains complete articulation control while reducing the overall volume of the end effector, making it more suitable for minimally invasive surgical applications.
3Measurement precision
If multiple antagonistic tendons are used for actuation, then precise jaw positioning is achieved, but manufacturing cost increases
Solution Approach 1:
The patent reduces manufacturing cost by eliminating the need to manufacture, assemble, and maintain multiple separate tendon systems. The single tendon design requires fewer precision components, less complex assembly procedures, and reduced inventory of spare parts, all while maintaining precise jaw positioning through its coordinated actuation mechanism.
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 mechanism allows for a more compact, cost-effective, and reliable actuation of surgical instruments with improved force application and reduced energy consumption, enabling more intuitive and stable jaw movement.
Implementation Method 1
a pulley rotatable about a pulley axis spaced apart from and parallel to the jaw axis, the actuation member being in frictional engagement with the pulley such that pulling the actuation member causes the pulley to rotate
Data Source
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AI summary
An actuation mechanism comprising: a first jaw rotatable about a jaw axis and comprising a first slot; a second jaw rotatable about the jaw axis and comprising a second slot; a slider moveable along a slider axis between a first position and a second position and movably engageable with the first and second jaws, which slider comprises a first protrusion slidably receivable within the first slot and a second protrusion slidably receivable within the second slot, wherein each slot extends in a direction which is non- parallel to the slider axis when the respective protrusion is engaged with the slot; a return attachable to the actuation mechanism and spaced apart from the slider; andan actuation member operably engageable with both the slider and the return, the actuation member comprising a first end, a second end, a first portion that extends from the first end to the return, and a second portion that extends from the return to the second end, the first portion being fixable to the slider whereby movement of the first portion away from the return causes the slider to move towards the first position and movement of the second portion away from the return causes the slider to move towards the second position.