Flexible Spine Rigidization and Distal Tool Control

Solution Overview

Problem

Conventional flexible steerable instruments face challenges in maintaining position and controlling distal tools after rigidization, as tensile elements used for rigidization become ineffective for further manipulation, leading to increased complexity and size, which detracts from the advantages of minimally invasive surgery.

Innovation Solution

A surgical apparatus with an elongated flexible body and tensile elements that allow for both rigidization and manipulation of a distal tool, using a control member and bell crank mechanism to apply differential tension for steering and motion, enabling the instrument to maintain position and facilitate tissue manipulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If tensile elements are used to rigidize the instrument, then the instrument achieves stable positioning, but the tensile elements become ineffective for controlling the distal tool and additional components are required

Engineering Contradiction:

Improveinstrument positioning stabilityVSAvoidinstrument component complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The tensile elements are designed to perform dual functions: they provide rigidization forces to stabilize the instrument segments and simultaneously serve as control elements for manipulating the distal tool. This multi-functionality eliminates the need for separate control mechanisms, reducing overall device complexity while maintaining positioning stability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the rigidization function and tool control function into a single integrated system using the same tensile elements. By merging these two previously separate functions into one unified mechanism, the instrument achieves both stable positioning and effective distal tool control without requiring additional components.

Inventive Principle:

Principle #5Merging (Combining)

2Ease of operation

If additional components are incorporated to control the distal tool after rigidization, then tool manipulation is enabled, but the cost, complexity and overall size of the instrument increase

Engineering Contradiction:

Improvedistal tool controllabilityVSAvoidinstrument structure complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The tensile elements are designed to perform dual functions: they provide rigidization forces to stabilize the instrument segments and simultaneously serve as control elements for manipulating the distal tool. This multi-functionality eliminates the need for separate control mechanisms, reducing overall device complexity while maintaining positioning stability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If additional components are incorporated to control the distal tool after rigidization, then tool manipulation is enabled, but the overall size of the instrument increases

Engineering Contradiction:

Improvedistal tool controllabilityVSAvoidinstrument size

Core Design Contradiction:

Ease of operationVSVolume of moving object

Solution Approach 1:

The patent combines the rigidization function and tool control function into a single integrated system using the same tensile elements. By merging these two previously separate functions into one unified mechanism, the instrument achieves both stable positioning and effective distal tool control without requiring additional components.

Inventive Principle:

Principle #5Merging (Combining)

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 apparatus effectively rigidizes the instrument for stable positioning while allowing for continued control and manipulation of the distal tool, reducing the need for additional components and maintaining the benefits of minimally invasive procedures.

Implementation Method 1

tensile elements are coupled to the distal segment to allow the segments to be drawn into high frictional contact with one another thereby rigidizing the instrument

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

The control member and the end effector may include a bell crank, which is connected to the tensile elements such that a pivotal movement of one bell crank effects corresponding pivotal movement in the other bell crank

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentUS8246575B2Flexible hollow spine with locking feature and manipulation structure

Publication Date: 2012.08.21 COVIDIEN LP

AI summary

An apparatus is disclosed for introducing surgical instruments into a body cavity. The apparatus includes a series of interconnected segments configured to pivot relative to one another allowing an end effector to be steered into position. The apparatus is also capable of achieving a rigidized state wherein the interconnected segments are in high frictional contact with one another providing a stable platform for the manipulation of tissue. Tensile elements are attached to the end effector and a control member such that an operator may use the same control member to both rigidize the instrument and also to thereafter control the end effector.