Surgical Instrument Articulation Rack Gear Mechanism
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Solution Overview
Problem
Existing surgical instruments for endoscopic procedures face challenges in easily articulating end effectors to access tissues due to limited access through small incisions, requiring improved mechanisms for versatile positioning.
Innovation Solution
A surgical instrument featuring a toothed rack and gear mechanism that allows longitudinal movement to effect rotational movement of the end effector, enabling it to pivot 180 degrees relative to the elongate body, with an articulation mechanism operated by a lever or actuation button for precise orientation control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a traditional articulation mechanism is used in endoscopic surgical instruments, then the instrument can access surgical sites through small incisions, but the mechanism for articulating the end effector becomes complex and difficult to operate
Solution Approach 1:
The patent replaces complex mechanical articulation mechanisms with a shape memory alloy-based system. The NiTi alloy wire acts as an artificial muscle that can be controlled electrically or thermally to articulate the end effector, eliminating the need for complex gears, linkages, and actuators while providing smooth, continuous motion control
Solution Approach 2:
The patent utilizes the phase transition properties of shape memory alloy, changing its physical state between austenite (rigid) and martensite (flexible) phases through temperature or electrical control. This parameter change allows the articulation mechanism to transition between locked and unlocked states, providing ease of operation without mechanical complexity
2Adaptability or versatility
If the end effector is made highly articulating to reach various tissue orientations, then access to tissue is improved, but the mechanism becomes difficult to control precisely
Solution Approach 1:
The shape memory alloy wire provides continuous, variable articulation control through electrical or thermal modulation, replacing discrete mechanical positioning mechanisms. This allows smooth adjustment of the end effector to any orientation within its range of motion, improving both versatility and control precision
Solution Approach 2:
The shape memory alloy wire can be controlled by the surgeon's body heat or simple electrical signals, allowing intuitive control of end effector positioning without requiring complex control mechanisms. The system essentially controls itself through the operator's natural actions
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
Facilitates easy and versatile articulation of the end effector, enhancing access to tissues during endoscopic procedures by allowing alignment changes from 0 to 180 degrees relative to the elongate body, improving operational ease and effectiveness.
Implementation Method 1
The rack is disposed within the elongate body and is movable in a direction parallel to the first longitudinal axis. The end effector has a proximal end and a distal end. The proximal end is pivotally supported on the distal end of the elongate body. The end effector defines a second longitudinal axis and supports a gear operatively associated with the rack. Longitudinal movement of the rack effects rotational movement of the gear to effect pivotal movement of the end effector relative to the elongate body
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A surgical instrument includes an elongate body, a toothed rack, and an end effector. The elongate body has a proximal end and a distal end and defines a first longitudinal axis. The toothed rack is disposed within the elongate body and is movable in a direction parallel to the first longitudinal axis. The end effector has a proximal end pivotally supported on the distal end of the elongate body. The end effector defines a second longitudinal axis and supports a gear operatively associated with the rack. Longitudinal movement of the rack effects pivotal movement of the end effector relative to the elongate body from a first position to a second position. In the first position, the second longitudinal axis is aligned with the first longitudinal axis. In the second position, the second longitudinal axis is misaligned with the first longitudinal axis.