Articulatable End Effector Cable Actuation for Multi-Plane Alignment
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Solution Overview
Problem
Current medical instruments with articulatable end effectors face limitations in flexibility and independent alignment within patients, particularly when used with endoscopes, as they often restrict movement to a single plane and are hindered by tube bending during insertion.
Innovation Solution
The development of medical instruments featuring flexible tubes, activation wires, and lengthwise-translatable cables or drive screws allows for articulation of end effectors relative to the proximal member, enabling independent alignment with endoscopes and multiple plane articulation, unhindered by tube bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional pull wire mechanisms are used to articulate the end effector, then the structure remains simple, but the articulation is restricted to a single plane and flexibility is reduced
Solution Approach 1:
The patent transitions from single-plane articulation to multi-plane articulation by introducing cables that can articulate the end effector about multiple axes. The end effector assembly includes mechanisms for articulation about a first axis and a second axis that is non-parallel to the first axis, enabling three-dimensional positioning and significantly increasing adaptability.
Solution Approach 2:
The patent employs nested structural arrangements where the end effector assembly is positioned within the distal portion of the flexible insertion tube, and articulation mechanisms are integrated within the tube structure. The cables run through the tube length to connect the proximal articulation control to the distal end effector, creating a nested configuration that enables complex motion within a compact form.
2Ease of operation
If the tube is made flexible for insertion, then ease of insertion is improved, but tube bending hinders articulation precision
Solution Approach 1:
The patent divides the insertion tube into functionally distinct segments: a flexible insertion tube portion for navigation and an articulated end effector assembly for precise positioning. The articulation mechanisms are segregated into the end effector assembly, allowing the flexible tube to bend during insertion while the articulated portion maintains precise control independent of tube bending.
Solution Approach 2:
The patent introduces articulation control cables as intermediary elements that transmit articulation forces from the proximal control mechanism through the flexible tube to the distal end effector. These cables maintain tension and control precision despite tube bending, acting as intermediaries that decouple the flexibility needed for insertion from the precision needed for articulation.
3Adaptability or versatility
If the end effector is integrated with the tube, then device simplicity is maintained, but independent alignment with endoscope is not possible
Solution Approach 1:
The patent implements dynamic articulation mechanisms that allow the end effector to be positioned independently of the tube orientation. The end effector assembly can articulate about multiple axes to achieve independent alignment with the endoscope, enabling the operator to align the end effector and endoscope independently even when the tube is bent or positioned at various angles.
Data Source
AI summary
A medical instrument includes a flexible tube, a distal member, a flexible end-effector activation wire, a proximal member, and a flexible first cable. The distal member is connected to the distal tube portion. The activation wire is positioned within the tube. The proximal member is attached to the tube. The first cable is positioned outside the tube, is substantially transversely constrained by the proximal member, and has a first distal cable portion attached to the distal member. Lengthwise translation of the first cable articulates the distal member with respect to the proximal member. Another instrument includes a drive screw which articulates an end effector (e.g., a grasper) pivotally connected to a tube. An additional instrument includes a drive screw which articulates a distal medical instrument member pivotally connected to a tube. A medical end effector (e.g., a snare) is positionable in a lumen of the distal medical instrument member.