Modified Polystyrene Intraocular Lens Flexibility
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Solution Overview
Problem
Polystyrene materials are unsuitable for intraocular lenses due to their high glass transition temperature, lack of flexibility, and susceptibility to oxidation, which makes them difficult to fold and insert through small incisions, despite having desirable properties like high strength and refractive index.
Innovation Solution
Development of a polymeric ophthalmic device material comprising at least 50% polystyrene with specific structural modifications, including cross-linking and incorporation of butadiene rubber, to enhance flexibility and mechanical properties, while minimizing oxidation and glistening issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polystyrene is used for intraocular lenses, then high strength and refractive index are achieved, but flexibility and ability to fold for insertion through small incisions deteriorate
Solution Approach 1:
The patent modifies the chemical structure of polystyrene by introducing substituent groups (R1, R2, R3) at different positions on the phenyl ring, which changes the glass transition temperature and flexibility parameters while maintaining the core polystyrene backbone for strength and refractive index properties
Solution Approach 2:
The invention creates a composite polymer structure where modified polystyrene units are combined with other polymer components to achieve a material that exhibits both the high strength/refractive index of polystyrene and the flexibility needed for surgical insertion through small incisions
2Ease of operation
If butadiene rubber is incorporated with polystyrene to provide flexibility, then ability to fold and compress for insertion improves, but oxidation susceptibility and glistening formation worsen
Solution Approach 1:
The patent removes the harmful unsaturated double bonds from the butadiene rubber structure through chemical modification or replacement, extracting the flexibility benefit while eliminating the oxidation susceptibility and glistening formation problems associated with the original butadiene structure
Solution Approach 2:
The invention converts the potentially harmful unsaturated bonds in butadiene rubber into beneficial saturated structures that provide flexibility without oxidation susceptibility, effectively transforming a harmful chemical feature into a beneficial mechanical property
3Illumination intensity
If polystyrene is used for intraocular lenses, then high refractive index is achieved, but ability to be pushed through small cartridge tip deteriorates
Solution Approach 1:
The patent adjusts the glass transition temperature and molecular chain flexibility parameters of polystyrene through structural modifications, enabling the material to be soft and foldable at surgical temperatures for easy insertion through small cartridge tips, while maintaining high refractive index for optical performance
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 modified polystyrene material achieves the necessary flexibility for insertion through small incisions, maintains desirable mechanical and thermal properties, and reduces glistening, making it suitable for intraocular lenses and other ophthalmic devices.
Implementation Method 1
addition of butadiene during the polymerization of polystyrene allows the butadiene to be chemically bonded with the polystyrene. The butadiene can be grafted to the polystyrene backbone or can be integrated into the backbone itself
Implementation Method 2
Such properties can allow the material to be folded and compressed for insertion through small inner diameters of injection cartridges
Data Source
AI summary
Disclosed are improved ophthalmic and otorhinolaryngological device materials and devices formed therewith. The device materials are soft, high refractive index styrenic device materials that are used to form the ophthalmic or otorhinolaryngological devices, particularly ophthalmic implants (e.g., intraocular lenses).