Bendable Medical Shaft With Angled End Faces
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Solution Overview
Problem
Existing medical hand instruments with bendable shafts suffer from limitations such as fixed angulation, large bending radius, and inability to adjust angles intraoperatively, which restrict their use in tight spaces and endoscopic operations.
Innovation Solution
A shaft design with a distal section that can be bent during operation, featuring angled end faces on both shaft sections that allow continuous adjustment without changing the angle under load, integrated rotary mechanism control, and a pivot joint that is stable and insensitive to external forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a plastic stent and wire strands are used to create flexibility, then the tip can be bent, but the bending area becomes too long and the tip too flexible
Solution Approach 1:
The shaft is divided into distinct modular sections (proximal shaft section, distal shaft section, intermediate section) with the bending capability localized to a specific pivot joint between sections. This segmentation allows bending functionality to be concentrated in a small region rather than distributed over a long flexible area.
2Adaptability or versatility
If an open joint construction is used to allow angulation, then flexibility is achieved, but the angle changes under pressure and only small angles up to 36° are possible
Solution Approach 1:
The pivot joint is designed as a controlled dynamic system that allows angulation movement during operation but maintains a fixed, stable angle once positioned. The joint can be adjusted to desired angles and then locked to prevent angle changes under operational pressure, combining flexibility with stability.
3Reliability
If a fixed angulation shaft is used, then the handpiece can be selected for specific angles, but the bending radius is large and takes up space, and the angle cannot be adjusted intraoperatively
Solution Approach 1:
The shaft system transitions from a fixed-angle design to a dynamically adjustable design where the distal shaft section can be angled relative to the proximal section during operation. The pivot joint allows the angle to be changed intraoperatively while maintaining stability once positioned.
Solution Approach 2:
The shaft is segmented into adjustable sections that can be independently positioned. The distal shaft section can be rotated relative to the proximal section via the pivot joint, enabling angle adjustment without requiring a large bending radius.
4Measurement precision
If the distal shaft section is bent during operation, then precise positioning in tight spaces is achieved, but the angle between shaft sections must remain stable under load
Solution Approach 1:
The pivot joint is designed as a controlled dynamic system that allows precise angular adjustment during positioning, then locks to maintain a fixed angle under operational loads. This ensures the bent position remains stable and predictable during use.
Solution Approach 2:
The pivot joint includes self-locking or self-stabilizing features that automatically maintain the angled position once set, without requiring continuous external control. The joint structure itself provides the stability needed to maintain precision under load.
Data Source
AI summary
A shaft of or for a medical hand instrument includes a distal shaft section having a first end face and a proximal shaft section having a second end face. The first end face and second end face face one another. At least one of the end faces is set at an angle of incidence not equal to 90° with respect to the longitudinal axis of the shaft, so that different shaft shapes result depending on the relative rotational position of the two shaft sections.