Adjustable Inner Shaft Movement in Laparoscopic Medical Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laparoscopic medical devices require intricate machining and tight tolerances for precise threading, leading to increased production times and costs due to the difficulty in adjusting the inner shaft movement within the tube.
Innovation Solution
A medical device with an adjustable mechanism at the proximal end that allows for fine adjustment of the inner shaft's lengthwise movement within the tube, using abutment surfaces and a lock nut to constrain and position the shaft end, enabling precise control without interfering with the instrument tip's travel limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If threading is used to connect the tube and inner shaft to the tip, then precise control of the inner shaft movement is achieved, but manufacturing complexity and production time increase due to tight tolerances and intricate machining requirements
Solution Approach 1:
The device is divided into distinct functional segments: a fixed abutment surface attached to the tube and an adjustable abutment surface that can be independently positioned along the tube. This segmentation allows the movement control function to be separated from the structural components, enabling simpler machining of individual parts while maintaining precise control through the adjustable mechanism.
Solution Approach 2:
The abutment surface is made adjustable rather than fixed, allowing dynamic repositioning along the tube length. This enables the system to adapt the inner shaft's range of motion as needed while using simpler, less precise machining for the abutment surfaces themselves, replacing the need for complex precision threading.
2Reliability
If tight tolerances are specified for threading assembly, then correct operation of the tool is ensured, but production time increases due to repeated iterative machining and testing steps
Solution Approach 1:
The adjustable abutment surface can be positioned at different locations along the tube to fine-tune the inner shaft's range of motion. This adjustability allows the system to achieve reliable tool operation through positioning rather than relying on tight manufacturing tolerances, thereby eliminating repeated iterative machining and testing steps.
Solution Approach 2:
Instead of controlling tool operation reliability through fixed geometric parameters (threading pitch, thread depth), the system uses an adjustable parameter (abutment surface position) that can be modified without remanufacturing components. This allows quick adjustment of the inner shaft's movement characteristics to ensure correct tool operation.
3Manufacturing precision
If the inner shaft movement is constrained by fixed threading, then precise control is achieved, but adaptability decreases as no adjustment is possible after assembly
Solution Approach 1:
The abutment surface is designed to be adjustable along the tube length, transforming a static constraint system into a dynamic one. This allows the inner shaft's range of motion to be customized for different applications or to compensate for manufacturing variations, providing adaptability while maintaining precise control through the abutment mechanism.
Solution Approach 2:
The adjustable abutment mechanism allows users to self-adjust the inner shaft movement characteristics without requiring complex precision machining or specialized assembly procedures. The system serves itself by providing built-in adjustability that eliminates the need for custom machining for each application.
Data Source
AI summary
A medical device may include a tube having a first end and a second end, in which the first end can engage an instrument tip, an inner shaft disposed in the tube, a shaft end connected to the inner shaft and which can move lengthwise relative to the tube, a first abutment surface to abut a first shaft end stop of the shaft end, and a second abutment surface to abut a second shaft end stop of the shaft end generally opposite the first shaft end stop of the shaft end, in which the shaft end can slidably move along a length constrained by the abutment of the first shaft end stop against the first abutment surface and the second shaft end stop against the second abutment surface, and in which either one or both of the first abutment surface or the second abutment surface is positionally adjustable relative to the tube.