Surgical Adapter Centering Mechanism for Stable Articulation
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Solution Overview
Problem
Existing surgical instrument articulation mechanisms struggle with accurate control and stability when articulating end effectors about multiple axes, as forces applied can cause unintended movement and misalignment of articulation joints.
Innovation Solution
A joint assembly featuring a spring cage that aligns and secures first and second longitudinal axes, with drive shafts and links that rotate uniformly, and a coupling mechanism with a slider and biasing member to securely attach the tool assembly to the adapter, ensuring predictable and stable articulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an articulation joint includes a plurality of axes of articulation to improve accessibility, then the end effector can articulate about multiple axes simultaneously, but the degree of articulation becomes difficult to accurately control
Solution Approach 1:
The articulation mechanism is divided into separate universal joints, each responsible for articulation about a specific axis. This segmentation allows independent control of each articulation axis, resolving the control accuracy problem while maintaining multi-axis capability.
Solution Approach 2:
A centering mechanism acts as an intermediary between the universal joints, maintaining proper alignment and spacing between them. This ensures that forces are distributed evenly and articulation control remains precise across all axes.
2Adaptability or versatility
If multiple universal joints are used to achieve desired articulation angles, then accessibility to surgical site is improved, but the position of articulation joints varies in response to forces exerted between handle and end effector
Solution Approach 1:
The centering mechanism functions as a counterbalancing element that opposes and neutralizes the destabilizing forces exerted between the handle and end effector. This maintains stable joint positions while allowing full articulation range.
Solution Approach 2:
The centering mechanism creates a balanced force distribution among all universal joints, ensuring that no single joint bears excessive load. This equipotential force distribution maintains joint position stability throughout the articulation range.
3Measurement precision
If a spring cage centering mechanism is added to align articulation joints, then articulation control accuracy is improved, but device complexity increases
Solution Approach 1:
The spring cage serves multiple functions simultaneously: it centers the articulation joints, maintains spacing between universal joints, and provides force distribution. This multi-functionality achieves precise articulation control without proportionally increasing complexity.
Solution Approach 2:
The spring cage is a self-centering mechanism that automatically maintains proper joint alignment through its elastic properties. It requires no external actuation or complex control systems, achieving precision through passive mechanical design.
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 solution provides precise and uniform articulation of surgical instruments across multiple axes, enhancing control and stability during surgical procedures by maintaining aligned joint angles and secure attachment of the tool assembly.
Implementation Method 1
The spring cage urges the first and second supports towards an aligned position in which the first and second longitudinal axes are coaxially aligned
Implementation Method 2
The spring cage engages the first link to effect uniform articulation across the joint assembly in response to articulation of the second support relative to the first support
Data Source
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Figure 5
AI summary
A joint assembly including first and second supports, a spring cage, first and second drive shafts, and first and second cables. The spring cage having a first end fixed to the first support and a second end fixed to the second support and defining a spring channel between the first and second supports. The first drive shaft rotatably disposed along a first longitudinal axis defined by the first support and the second drive shaft rotatably disposed along a second longitudinal axis defined by the second support. The first and second cables extending through the first support and having an end secured to the second support. The first and second cables translatable in a direction parallel to the first longitudinal axis to articulated the second support relative to the first support such that the second longitudinal axis is disposed at a total joint angle relative to the first longitudinal axis.