Electroactive Polymer Intraocular Lens for Dynamic Accommodation
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Solution Overview
Problem
Current intraocular lenses (IOLs) fail to effectively address presbyopia, a condition where the eye loses its ability to focus on near objects due to age-related loss of lens elasticity, leading to reliance on spectacles for near activities, and existing solutions like multifocal IOLs cause photic phenomena or require large incisions, while electroactive polymers face challenges in achieving practical mechanical displacement.
Innovation Solution
An intraocular lens with a transparent optic and an actuator comprising a stack of electroactive material layers with interdigitated electrodes, which changes curvature in response to applied voltage, allowing for dynamic focus adjustment without overlaying images or diminishing light, and incorporates energy harvesting mechanisms to optimize mechanical displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multifocal IOLs are used to improve near vision, then near and intermediate vision are improved, but photic phenomena such as halos and glare occur and contrast sensitivity is diminished
Solution Approach 1:
The patent employs a dynamic accommodation mechanism where the IOL can change its optical power continuously in response to ciliary muscle contraction, rather than providing fixed multiple focal points. This dynamic adjustment allows the lens to focus light precisely on the retina for near objects without creating multiple retinal images that cause halos and glare.
Solution Approach 2:
The patent replaces the static mechanical structure of multifocal IOLs with an electroactive polymer-based actuation system. This system uses electrical fields to induce mechanical deformation in the electroactive polymer layers, which in turn changes the lens curvature and optical power dynamically, avoiding the photic phenomena associated with traditional multifocal designs.
2Adaptability or versatility
If pseudoaccommodating IOLs with mechanical mechanisms are used to mimic natural lens, then dynamic focus change is achieved, but large incisions are required causing iatrogenic corneal astigmatism
Solution Approach 1:
The patent uses thin electroactive polymer films as the actuation mechanism, which can be integrated into the IOL structure without requiring large incisions. These flexible thin films deform under electrical fields to change lens curvature, enabling dynamic focus adjustment through small incisions and thus avoiding iatrogenic corneal astigmatism.
Solution Approach 2:
The patent substitutes complex mechanical lever and fulcrum systems with an electroactive polymer-based actuation system. This electrical-mechanical transduction system achieves dynamic focus change through voltage application, eliminating the need for large incisions and complex mechanical components that cause surgical complications.
3Adaptability or versatility
If electroactive polymers are used to achieve lens curvature change, then dynamic accommodation is possible, but practical mechanical displacement is difficult to achieve
Solution Approach 1:
The patent employs a stacked configuration of multiple electroactive polymer layers with interdigitated electrodes, where each layer contributes to the overall displacement. This nested multi-layer structure amplifies the mechanical displacement effect, as the cumulative deformation of multiple layers produces sufficient curvature change for practical accommodation despite individual layer displacements being small.
Solution Approach 2:
The patent uses composite structures combining electroactive polymer layers with supportive materials and interdigitated electrode patterns. This composite design enhances the mechanical displacement output by optimizing the interaction between the electroactive polymer and the electrode structure, enabling practical accommodation range while maintaining the benefits of electroactive actuation.
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 lens provides a range of focal lengths for improved near vision correction with minimal photic phenomena, reducing reliance on spectacles and allowing for implantation through small incisions, while the energy harvesting mechanism enhances mechanical stability and ease of handling.
Implementation Method 1
an actuator comprising a stack of electroactive material layers with interdigitated electrodes, which changes curvature in response to applied voltage
Implementation Method 2
incorporates energy harvesting mechanisms to optimize mechanical displacement
Data Source
Figure 1
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AI summary
An intraocular lens (IOL) has a clear optic and means for actuating change in curvature in at least a portion the clear optic. The intraocular lens (IOL) can have anterior and posterior portions spaced apart by a cavity, and an actuator for urging change in curvature in at least one of said portions, with energy provided by an energy harvesting mechanism incorporated into haptics of said IOL.