Intraocular Lens Mandrel Structure for Wax-Free Haptic Milling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for manufacturing intraocular lenses face challenges such as the need for precise mandrel alignment, manual removal of wax residues, and reduced tool life due to wax usage, which complicates the milling process and affects the quality of the finished lens.

Innovation Solution

A mandrel design with a central cavity and peripheral projection to securely hold the intraocular lens blank, allowing for precise machining and milling, and a method involving mechanical deblocking without solvents to eliminate wax residues, enhancing the efficiency and quality of the intraocular lens production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If wax is used to hold the intraocular lens blank during machining and milling, then the blank is securely held in place, but wax residues remain on the haptic surface and reduce tool life

Engineering Contradiction:
Improveholding strengthVSAvoidwax residues
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the harmful wax material from the holding process by replacing it with a wax-free mandrel system. The mandrel directly holds the intraocular lens blank through mechanical engagement features (such as recesses and protrusions) without requiring wax adhesive, thereby eliminating wax residues from the haptic surface and preventing tool life reduction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mandrel acts as an intermediary between the machining tool and the intraocular lens blank. Instead of using wax as a mediator that leaves residues, the mandrel provides direct mechanical support and positioning through its structural features, serving as a clean intermediary that does not contaminate the haptic surface.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If water soluble wax is used to hold the blank, then the blank is secured during machining, but the lens hydrates in the presence of dissolved wax impurities

Engineering Contradiction:
Improveholding strengthVSAvoidlens hydration
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent removes water soluble wax from the process entirely, replacing it with a mandrel-based holding system. This extraction eliminates the source of dissolved wax impurities that would otherwise cause lens hydration, while maintaining secure holding through mechanical engagement features.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If manual deblocking is used to remove wax residues, then complete removal is achieved, but productivity is reduced

Engineering Contradiction:
ImprovecleanlinessVSAvoiddeblocking speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent extracts the deblocking step from the manufacturing process by eliminating wax usage entirely. The mandrel system allows for direct mechanical release of the intraocular lens blank without requiring manual or chemical deblocking operations, thereby maintaining cleanliness while dramatically improving productivity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mandrel holding system enables continuous manufacturing flow by eliminating the interruptive deblocking step. The intraocular lens blank can be directly transferred from the mandrel to the next processing stage without stopping for manual wax removal, maintaining continuous productive action.

Inventive Principle:
Principle #20Continuity of useful action

4Manufacturing precision

If the mill penetrates through the back surface of the haptic disk, then the haptic is formed, but tool life is reduced due to wax contact

Engineering Contradiction:
Improvehaptic formationVSAvoidtool life
Core Design Contradiction:
Manufacturing precisionVSDuration of action of stationary object

Solution Approach 1:

The patent extracts wax from the machining environment, eliminating the harmful interaction between wax and the milling tool. The mandrel holding system allows the mill to penetrate and form the haptic without contacting wax residues, thereby preserving tool life while maintaining haptic formation precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2988925B1System for holding an intraocular lens blank and method of making an intraocular lens using the same
Publication Date: 2024.02.14 BENZ RESEARCH & DEVELOPMENT CORP
  • EP2988925B1 patent drawingFigure 1(a)~1(d)
  • EP2988925B1 patent drawingFigure 2(a)~2(d)
  • EP2988925B1 patent drawingFigure 3(a)~3(d)

AI summary

A mandrel (300) for holding an intraocular lens blank (200) during manufacturing includes an intraocular lens holding section configured to hold an intraocular lens, the intraocular lens holding section including: a central cavity (310) configured to hold a mounting material (315) such that the mounting material contacts an optic of the intraocular lens blank when the intraocular lens blank is mounted on the mandrel, and a projection (325) extending around a periphery of the central cavity, the projection having an outer wall (330) and an inner wall (335), and the projection being configured such that an outer peripheral edge of the intraocular lens blank extends up to or beyond the projection when the intraocular lens blank is mounted on the mandrel. A second mounting material (320) is deposited in the first trench (340) and then the haptic is milled using e.g. an end mill (365).