Soft Intraocular Lens Tip Hardness for Insertion Ease

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Solution Overview

Problem

Conventional soft intraocular lenses with support arms made of the same material as the optical lens section often stick together during folding, requiring operator intervention to separate, which can cause damage and increase operator stress due to the need for forceful separation.

Innovation Solution

A one-piece soft intraocular lens design where the tip end part of the support arm is made of a harder material, such as PMMA, positioned outside a 5mm radius circle centered on the optical lens section, reducing adhesiveness and facilitating easy separation and insertion, while the base end side is made of the same soft material as the optical lens section.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the support arm section is made of the same soft material as the optical lens section, then the lens can be easily manufactured and is simple in structure, but the support arm section sticks to the optical lens section during folding, requiring operator intervention to separate

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidseparation ease
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The support arm section is designed with different material properties at different locations: the base end side portion is made of soft material (same as optical lens section) for ease of manufacture and integration, while the tip end part is made of hard material (different from soft material) to prevent sticking during folding and insertion. This local differentiation resolves the contradiction by having each region perform its specific function optimally.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If the support arm section is made of hard material, then stability in the eye is excellent, but the lens becomes complicated to manufacture and costs increase

Engineering Contradiction:
Improvestability in eyeVSAvoidmanufacturing complexity
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

Only the tip end part of the support arm section is made of hard material to provide stability in the eye, while the base end side portion remains soft for easier manufacturing. This localized hard material application provides the necessary stability without requiring the entire support arm to be hard, thus reducing manufacturing complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The support arm section uses composite material construction with two different materials: soft material for the base end side portion and hard material for the tip end part. This composite approach allows the support arm to achieve both ease of manufacture (soft portion) and stability in the eye (hard portion) simultaneously.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If the entire support arm section is made of hard material, then stability is improved, but the support arm section may be broken or separate from the bonded part during insertion from small incised wound

Engineering Contradiction:
Improvestability in eyeVSAvoidstructural integrity during insertion
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The tip end part is made of hard material to maintain stability in the eye, while the base end side portion is made of soft material to prevent breaking during insertion. This local material differentiation allows the support arm to be flexible enough to be inserted through small incised wounds without breaking, while still providing stability once in the eye.

Inventive Principle:
Principle #3Local quality

4Ease of operation

If the support arm section is made of soft material, then the lens is easy to fold and insert from small incised wound, but the support arm section may stick to the optical lens section requiring forceful separation

Engineering Contradiction:
Improvefolding and insertion easeVSAvoidadhesiveness
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The base end side portion is made of soft material to enable easy folding and insertion, while the tip end part is made of hard material to reduce adhesiveness and prevent sticking to the optical lens section. This local differentiation allows the support arm to be flexible during insertion but non-sticking at the tip end.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The material properties (hardness, adhesiveness) are changed at different locations of the support arm section. The tip end part has different material parameters (harder, less adhesive) compared to the base end side portion (softer, more adhesive), which prevents harmful sticking while maintaining ease of folding and insertion.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2399548B1Soft intraocular lens and method of manufacturing same
Publication Date: 2017.12.20 HOYA CORPORATION
  • EP2399548B1 patent drawingFigure 1(a)~1(b)
  • EP2399548B1 patent drawingFigure 2
  • EP2399548B1 patent drawingFigure 3(a)~3(d)

AI summary

There is provided a soft intraocular lens, comprising: an optical lens section 10 made of a foldable soft material; and a support arm section 20 formed so as to protrude outward from an outer peripheral edge of the optical lens section 10 for holding the optical lens section 10 in an eye, wherein a tip end part 22 of the support arm section 20 is made of a different kind of material which is harder than a soft material of other portion of the soft intraocular lens 1, and adhesiveness of the tip end part 22 of the support arm section 20 is set to be lower than the adhesiveness of other portion of the soft intraocular lens 1.