Cable-Driven Surgical Instrument Articulation for Confined Navigation
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Solution Overview
Problem
Existing robotic surgical instruments face limitations in navigating within a surgical site via rotation and manipulation alone, lacking sufficient flexibility and control over end effector orientation.
Innovation Solution
The surgical instrument incorporates a shaft with an articulating section and articulation cables, utilizing an articulation mechanism with capstans or a swashplate assembly to articulate the end effector assembly in multiple directions through tensioning and slackening of cables, allowing for enhanced maneuverability and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If rotation features are incorporated to enable end effector orientation, then the ability to manipulate the end effector is improved, but the ability to navigate within the surgical site remains limited
Solution Approach 1:
The shaft is divided into a proximal section and an articulating section, allowing independent movement of the articulating section relative to the proximal section. This segmentation enables the end effector to navigate through confined surgical spaces while maintaining manipulation capability through the distal articulation joint.
Solution Approach 2:
The invention adds an articulation degree of freedom at the distal end of the shaft, enabling the end effector to articulate relative to the proximal shaft section. This additional dimensional movement transforms the system from simple rotation to multi-axis articulation, significantly improving navigation capability within the surgical site.
2Adaptability or versatility
If articulation cables are used to articulate the end effector, then the flexibility and control are improved, but the device complexity increases
Solution Approach 1:
The invention replaces complex multi-axis mechanical articulation mechanisms with a cable-driven system. Articulation cables extend through the proximal shaft section to the articulating section, where tensioning and slackening of these cables articulates the end effector in opposite directions, simplifying the overall mechanical structure while maintaining flexibility.
Solution Approach 2:
The articulation cables act as flexible elements that transmit tension forces through the shaft to articulate the end effector. This flexible cable system provides smooth, continuous articulation movement without requiring complex rigid mechanical joints or gears.
3Measurement precision
If capstans are used to tension the articulation cables, then the control precision is improved, but the manufacturing complexity increases
Solution Approach 1:
The capstans are configured to rotate in first and second directions to dynamically tension and slacken the articulation cables as needed. This dynamic rotation capability allows precise control of cable tension to articulate the end effector in opposite directions, with the capstan rotation direction being controlled based on the desired articulation movement.
Solution Approach 2:
The capstans serve as intermediary components between the control system and the articulation cables. By winding and unwinding the cables around the capstan periphery, the system achieves precise tension control without requiring direct mechanical connection or complex actuation mechanisms at the end effector.
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 articulation mechanism enables precise and flexible articulation of the end effector, facilitating improved navigation and manipulation within the surgical site, enhancing the instrument's operational capabilities.
Implementation Method 1
a first capstan including a proximal end portion of the first articulation cable at least partially wound thereabout. The first capstan is configured to rotate in a first direction to wind up the proximal end portion of the first articulation cable to tension the first articulation cable and in a second direction to unwind the proximal end portion of the first articulation cable to slacken the first articulation cable.
Data Source
AI summary
A surgical instrument includes a housing, an articulating shaft, and an end effector assembly extending from the articulating shaft. Tensioning a first articulation cable and slackening a second articulation cable articulates the end effector assembly in a first direction and the opposite articulates the end effector assembly in a second, opposite direction. An articulation mechanism includes first and second capstans including proximal end portions of the first and second articulation cables at least partially wound thereabout. The first capstan is configured to rotate in a first direction to wind up the proximal end portion of the first articulation cable to tension the first articulation cable and in a second direction to unwind the proximal end portion of the first articulation cable to slacken the first articulation cable. The second capstan acts in an opposite manner to tension and slacken the second articulation cable.