Endoscope Insertion Portion With Graded Bending Stiffness
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Solution Overview
Problem
Conventional endoscope systems face difficulties in maintaining appropriate bending stiffness of the insertion portion while ensuring sufficient slide length, particularly in varying conditions such as postoperative patients undergoing the Roux-en-Y Method, where the required bending stiffness and its position vary depending on the removal range and observation position.
Innovation Solution
The endoscope system incorporates a flexible portion with a bending stiffness change portion that increases in stiffness from the distal end to the proximal end, allowing for adjustable bending stiffness without lengthening the insertion assisting tool, thereby maintaining slide length and preventing unnecessary warping. This is achieved through a projection region where the flexible portion projects from the overtube, with the bending stiffness change portion designed to provide necessary stiffness in response to varying patient conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the overtube is made relatively long to secure bending stiffness, then bending stiffness is improved, but slidable length becomes short and insertion becomes difficult
Solution Approach 1:
The insertion portion is designed with non-uniform bending stiffness distribution, where the distal end has lower bending stiffness for flexibility during insertion and the proximal end has higher bending stiffness for stability. This local variation in stiffness properties allows the shaft to achieve appropriate bending characteristics without requiring excessive length, thereby maintaining sufficient slidable length for easy insertion while securing necessary bending stiffness.
2Ease of operation
If the insertion portion is made flexible to facilitate insertion, then ease of insertion is improved, but the insertion portion becomes prone to warping
Solution Approach 1:
The shaft incorporates a bending stiffness change portion that creates a gradient in stiffness along its length. The distal end maintains lower stiffness for flexibility during insertion, while the proximal end develops higher stiffness to prevent warping. This localized variation in mechanical properties allows the shaft to simultaneously achieve ease of insertion and resistance to warping without requiring uniform stiffness throughout.
3Stability of the object's composition
If the bending stiffness is increased to prevent warping, then stability is improved, but the insertion portion becomes difficult to insert
Solution Approach 1:
The insertion portion features a graded bending stiffness structure where the distal end has reduced stiffness to facilitate smooth insertion through the esophagus, while the proximal end has increased stiffness to prevent warping during insertion and maintain positional stability. This spatial variation in mechanical properties resolves the contradiction between ease of insertion and warping resistance by applying appropriate stiffness characteristics to appropriate regions.
4Length of moving object
If the flexible portion is made longer to maintain slide length, then slide length is improved, but bending stiffness becomes insufficient
Solution Approach 1:
The shaft design incorporates a bending stiffness change portion that creates a stiffness gradient along the flexible portion. This allows the flexible portion to extend to the required length for maintaining slide length while the progressive increase in bending stiffness from distal to proximal end ensures sufficient stiffness is achieved without compromising the extended length. The graded structure enables the shaft to be both long enough for proper positioning and stiff enough to maintain stability.
Data Source
AI summary
There is provided an endoscope system which can secure appropriate bending stiffness of an insertion portion while maintaining the slide length of an endoscope insertion portion. According to one aspect of one of the present invention, in an endoscope system including an endoscope and an insertion assisting tool in which the endoscope is inserted and which assists the insertion of an endoscope insertion portion into a body, a flexible portion of the endoscope insertion portion includes a projection region which projects from the distal end opening of a tube body when the endoscope insertion portion is located in the distal end position in a movable range with respect to the tube body of the insertion assisting tool, and the projection region includes a bending stiffness change portion in which bending stiffness increases from a first position on the distal end side to a second position on the proximal end side.