Beveled IOL Injector Cartridge Tip Design
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Solution Overview
Problem
Conventional IOL injector cartridges often damage the intraocular lens (IOL) during insertion due to sharp edges and high stress concentrations, leading to potential scratches and splits in the cartridge material, limiting the minimum size of the distal tip and affecting the precision of the delivery process.
Innovation Solution
The design of an IOL injector cartridge with a beveled distal end featuring a leading tip and a trailing heel, where the distal face is either straight, curved, or chamfered, with an inner corner angle greater than 60° to reduce the risk of damage to the IOL and minimize stress concentrations, allowing for a smaller and more robust cartridge tip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the distal end of the cartridge is made sharp to facilitate insertion through the corneal incision, then the ease of operation is improved, but the IOL or cartridge tip is damaged during the process
Solution Approach 1:
The distal end is segmented into distinct functional zones: a sharp leading tip for penetration, a beveled surface for controlled entry, and a rounded trailing portion to prevent damage. This segmentation allows each zone to perform its specific function optimally without compromising the others.
Solution Approach 2:
Different portions of the distal end have different geometric characteristics tailored to their specific functions. The leading tip is sharp for penetration, the beveled surface provides controlled entry at an angle, and the trailing portion is rounded to minimize damage. This local differentiation resolves the contradiction between sharpness for insertion and roundness for safety.
2Manufacturing precision
If the cartridge tip is made smaller to fit through the incision, then the precision of delivery is improved, but the strength of the cartridge material is reduced
Solution Approach 1:
The trailing portion of the distal end is curved or rounded rather than sharp or angular. This curvature distributes stress more evenly and prevents stress concentration at the trailing edge, allowing the cartridge tip to be smaller while maintaining sufficient material strength.
Solution Approach 2:
The geometry parameters of the distal end are optimized: the bevel angle is set to 45 degrees, the inner corner angle is greater than 60 degrees, and the outer corner angle is greater than 120 degrees. These parameter changes reduce stress concentration and improve structural integrity at reduced sizes.
3Productivity
If the inner corner angle at the distal end is made sharp to minimize the cartridge size, then the productivity is improved, but the chance of scratching the IOL increases
Solution Approach 1:
The inner corner at the distal end is rounded rather than sharp. This curvature eliminates sharp edges that could scratch the IOL while maintaining a compact cartridge design. The rounded geometry smooths the transition of the IOL through the cartridge tip.
Solution Approach 2:
The inner corner angle is specifically designed to be greater than 60 degrees, which significantly reduces the likelihood of scratching the IOL compared to sharper angles, while still maintaining an efficient and compact cartridge structure.
Data Source
AI summary
This intraocular lens (IOL) injector cartridge has a proximal opening in a main body for receiving an IOL. The main body has a lumen that extends longitudinally to a distal end having an opening smaller than the IOL. Passage through the lumen compresses or rolls the IOL so that when the distal end is inserted through a small incision in the eye the IOL can be expelled into the capsular bag. The distal end of the cartridge is beveled with a leading tip in front of a trailing heel. The characteristics of the beveled end are such that damage to the IOL is reduced. The bevel may be straight or curved and includes a distal face defined by the thickness of the distal end between the lumen and an exterior surface. The distal face may be flush with the bevel or chamfered. An inner corner angle between the distal face and the lumen is ≥60° to reduce the chance of scratching the IOL as it passes out of the distal opening.