Intraocular Lens Mandrel for Cryogenic Alignment and Centering
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Solution Overview
Problem
Conventional techniques for machining intraocular lenses, particularly hydrophobic materials, face challenges in ensuring accurate alignment and centering of the haptic during the milling process, especially when using cryogenic methods.
Innovation Solution
A mandrel with a central cavity and projections to support the lens blank, combined with a ring that fits within the periphery to hold the opposing surface, and a hollow channel for freezing liquid to provide stability during machining, ensuring precise alignment and centering of the haptic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional techniques are used to machine hydrophobic intraocular lenses using cryogenic methods, then the lens can be fabricated, but accurate alignment and centering of the haptic during milling is difficult to achieve
Solution Approach 1:
The mandrel is segmented into multiple functional components: a central cavity for holding the lens blank, projections on the cavity surface to support the first surface of the blank, and a ring that fits within the periphery to hold the second opposing surface. This segmentation allows each component to perform its specific function optimally, ensuring precise alignment and centering during machining operations
Solution Approach 2:
The mandrel acts as an intermediary device between the lens blank and the machining equipment. By providing a standardized interface with the central cavity, projections, and ring structure, it mediates the holding and positioning process, enabling accurate alignment without requiring direct manipulation of the fragile lens blank
2Manufacturing precision
If a simple mandrel structure is used to hold the lens blank, then the device complexity is reduced, but the stability and alignment precision during machining deteriorates
Solution Approach 1:
The mandrel structure is divided into distinct functional segments: the central cavity for blank placement, surface projections for support, and a peripheral ring for securing the blank. This segmentation provides multiple points of contact and control, enhancing stability during machining while keeping each individual component relatively simple in design
Solution Approach 2:
The ring fits within the periphery of the lens blank holding section, creating a nested structure where one component (the ring) is contained within another (the holding section). This nesting arrangement maximizes the use of space and provides enhanced stability without significantly increasing overall device complexity
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 mandrel maintains precise alignment and stability of the lens blank, allowing for accurate machining of hydrophobic intraocular lenses, even during cryogenic processes, and enables shelf-stable storage and transportation of partially completed lenses for later manufacturing.
Implementation Method 1
a hollow channel is formed within the central cavity, the hollow channel extending into the shank
Implementation Method 2
The holding section includes a central cavity formed concentrically with the central axis of the mandrel. Projections are formed on the surface of the central cavity to support a first surface of the lens blank. A ring fits within the periphery of the lens blank holding section, and holds a second opposing surface of the lens blank
Data Source
AI summary
A mandrel for holding and positioning an intraocular lens blank during manufacturing includes a shank portion having a central axis and a lens blank holding section configured to hold the lens blank. The holding section includes a central cavity formed concentrically with the central axis of the mandrel. Projections are formed on a surface of the central cavity and are configured to support a first surface of the lens blank at a fixed distance from the surface of the central cavity. A ring fits within a peripheral portion of the central cavity to hold a second opposing surface of the lens blank. A method for making an intraocular lens using the mandrel includes filling the space formed under the first surface of the lens with a liquid, such as water, freezing the liquid, and then machining and/or milling the second surface of the lens blank.