Rotational Coupling Device for Surgical Instrument Actuators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical instruments with flexible actuators face challenges in providing suitable feedback and requiring excessive force for articulation and rotation, which complicates control and user experience, especially in endoscopic procedures where size constraints and flexibility interfere with control motions.
Innovation Solution
A rotational coupling device with hollow shafts and semi-flexible actuators allows for independent rotation and articulation of the end effector relative to the elongate shaft, using a unique coupling arrangement that transfers axial forces through input and output actuators, enabling precise control without adverse effects on the actuation wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If flexible actuators are used in endoscopic devices, then the device can navigate tortuous pathways, but control motions are transferred as longitudinal translations that interfere with shaft flexibility
Solution Approach 1:
The patent introduces a rotational degree of freedom at the distal end of the shaft, allowing the end effector to rotate independently of longitudinal actuator movements. This dimensional change separates control motions from shaft flexibility constraints, enabling both flexible navigation and precise control.
Solution Approach 2:
The shaft is divided into flexible and rigid segments, with the distal portion being rigid to provide stable control while the proximal portion remains flexible for navigation. This segmentation allows different portions of the shaft to fulfill different functional requirements simultaneously.
2Force
If electrical motors are used to lower force-to-fire, then actuation force is reduced, but user feedback from the working end is lost
Solution Approach 1:
The system uses the surgeon's own manual actuation forces to both move the end effector and provide tactile feedback. The mechanical linkage directly transmits both motion and force feedback without requiring external power sources or sensors, making the system self-sufficient for feedback provision.
Solution Approach 2:
The rigid distal shaft portion acts as a mechanical intermediary that transmits tactile feedback from the end effector back to the surgeon's hand, enabling sense of touch without electrical motors or electronic sensors.
3Ease of operation
If actuation wires are used for manual articulation, then surgeon control is maintained, but excessive force is required for articulation and rotation
Solution Approach 1:
The patent employs a three-bar linkage mechanism with curved geometries that provide mechanical advantage, reducing the force required by the surgeon to articulate and rotate the end effector while maintaining precise control.
4Ease of operation
If the end effector is rotated relative to the longitudinal axis, then articulation control is improved, but the actuation wire must rotate to avoid malfunction
Solution Approach 1:
The actuation wire is extracted from the rotating joint mechanism, allowing the end effector to rotate independently without the wire. The wire remains in a fixed position while the end effector rotates around it, eliminating the risk of wire malfunction due to rotation.
Data Source
AI summary
Rotational couplers for use with surgical devices that are actuated by semi-flexible actuators such as wires and the like. The couplers enable the actuators to apply various actuation motions to actuation features on the surgical device as well as other actuators to apply axial and rotational motions to the surgical device to manipulate the device into various orientations relative to an elongate shaft to which the device is movably attached.