Articulable Surgical Instrument Cable Routing

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Solution Overview

Problem

Existing laparoscopic surgical instruments with articulable ends face challenges in maintaining a small outer diameter while ensuring a reliable and safe articulation mechanism, often leading to cable damage and failure due to bending and friction issues, especially when bent to 90 degrees, which can compromise patient safety.

Innovation Solution

A uni-directional articulating surgical instrument with a 5 mm outer diameter, featuring a lumen and articulable segments connected via hinge pins and knuckle assemblies that route the actuation cable within the instrument, preventing cable exposure and damage, and utilizing stainless steel wire strands for the actuation cable, allowing for controlled articulation and return movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the instrument is bent to 90 degrees to achieve articulation, then the working tip can navigate around internal structures, but the actuation cable exits the confines and is subjected to damage and fraying

Engineering Contradiction:

Improvearticulation capabilityVSAvoidcable integrity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The actuation cable is nested within a protective cable routing channel that is integrated into the instrument structure. The channel follows the bend path of the instrument, ensuring the cable remains confined even when the instrument is articulated to 90 degrees or beyond. This nesting approach protects the cable from exposure and damage while maintaining full articulation capability.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

A cable routing channel acts as an intermediary structure between the actuation cable and the external environment. This channel mediates the stress and movement during articulation, guiding the cable through a protected path that prevents direct contact with sharp edges and reduces fraying risks.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the outer diameter is reduced to 5 mm to minimize incision size, then tissue trauma is reduced, but the internal components must be reduced in number and size while remaining robust

Engineering Contradiction:

Improvetissue traumaVSAvoidcomponent density

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Multiple functions are merged into integrated components. The cable routing channel is integrated into the instrument body structure rather than being a separate component. The knuckle joint and cable routing are combined into a unified design, reducing the number of discrete parts while maintaining robust functionality within the 5 mm diameter constraint.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The cable routing channel utilizes a flexible, thin-walled structure that can accommodate cable movement during articulation while maintaining a compact profile. This flexible channel design allows the system to maintain small dimensions without compromising the protection or functionality of internal components.

Inventive Principle:

Principle #30Flexible shells and thin films

3Ease of manufacture

If polymers are used at the knuckle region to simplify the structure, then manufacturing is easier, but the service life is very limited

Engineering Contradiction:

Improveknuckle fabricationVSAvoidservice life

Core Design Contradiction:

Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The knuckle joint utilizes a composite construction combining metal elements (for structural strength and durability) with polymer components (for ease of manufacturing and flexibility). This composite approach allows the knuckle to be manufactured using accessible techniques while achieving the longevity and reliability required for repeated surgical use.

Inventive Principle:

Principle #40Composite materials

4Ease of operation

If micro sheave with ball or roller bearing is used to improve articulation precision, then articulation control is enhanced, but the instrument is costly and reusable only a limited number of times

Engineering Contradiction:

Improvearticulation controlVSAvoidreusability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The complex bearing mechanisms (ball or roller bearings) are extracted from the design and replaced with a simpler friction-based articulation mechanism. This extraction eliminates the precision components that limited reusability while maintaining sufficient articulation control for surgical applications. The simpler mechanism is more robust and can withstand repeated use without the degradation issues associated with precision bearings.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS9642603B2Articulable surgical instrument

Publication Date: 2017.05.09 MICROLINE SURGICAL INC

AI summary

An instrument includes, a lumen, a handpiece affixed to the proximal end of the lumen and including an actuator, a proximal articulable segment, the proximal end of the proximal articulable segment pivotably attached to the distal end of the lumen via a proximal hinge pin extending in a direction generally perpendicular to a longitudinal axis of the lumen, an actuation cable extending from the actuator through the lumen and into the proximal articulable segment, and a cable router comprising a proximal pulley assembly rotatable about the proximal hinge pin, wherein the cable is wrapped about the proximal pulley assembly.