Curved Retinal Prosthesis Electrode Array
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing retinal prosthetic devices face challenges in providing stable and effective electrical stimulation to the retina due to issues with pressure distribution, edge sharpness, and compatibility with the spherical shape of the retina, leading to increased electrical resistance, potential retinal damage, and limited vision restoration in cases of blindness caused by photoreceptor degenerative diseases.
Innovation Solution
A flexible circuit electrode array with a thermoplastic polymer that can be curved to match the retinal shape, featuring a protective skirt and ribbed edges to reduce pressure and prevent tissue damage, along with a fold or twist design to facilitate secure attachment and minimize stress on the sclera, ensuring optimal electrical contact and reduced risk of retinal ischemia.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid electrode array is used to maintain stable electrical contact with the retina, then electrical contact stability is improved, but the array cannot adapt to the spherical shape of the retina causing increased electrical resistance and potential retinal damage
Solution Approach 1:
The electrode array employs a flexible polymer substrate that can conform to the curved surface of the retina, replacing rigid structures with flexible thin films that adapt to the spherical retinal geometry while maintaining stable electrical contact through continuous surface following
Solution Approach 2:
The electrode array is designed with a curved configuration that matches the spherical shape of the retina, transforming the flat rigid structure into a curved flexible form that adapts to the retinal surface geometry, reducing electrical resistance and improving contact stability
2Manufacturing precision
If the electrode array edges are made sharp to facilitate precise positioning, then positioning precision is improved, but retinal tissue damage increases due to edge trauma
Solution Approach 1:
The electrode array incorporates a protective skirt extending from the edges with locally varying properties: the skirt provides mechanical protection and distributes pressure along the edges, while the electrode regions maintain precision positioning capability, creating different functional zones with appropriate local characteristics
Solution Approach 2:
The protective skirt acts as a cushioning element positioned before the sharp edges can contact the retinal tissue, preventing direct trauma by distributing mechanical stress and protecting the retina from edge-related damage during implantation and operation
3Area of stationary object
If the electrode array is made large to cover more retinal area for broader vision restoration, then vision restoration coverage is improved, but pressure distribution on the retina becomes uneven causing retinal ischemia
Solution Approach 1:
The flexible polymer substrate allows the large electrode array to conform to the curved retinal surface, distributing pressure evenly across the entire contact area by following the retinal geometry, preventing localized high-pressure regions that would cause ischemia while maintaining broad coverage
Solution Approach 2:
The electrode array incorporates flexible and adaptable structures that can dynamically adjust to retinal movements and shape variations, maintaining uniform pressure distribution across the large contact area through elastic deformation and geometric adaptation
4Reliability
If a fold or twist design is added to the electrode array to facilitate secure attachment and minimize scleral stress, then attachment security is improved, but device complexity increases
Solution Approach 1:
The fold or twist design introduces controlled geometric features into the flexible electrode array, creating three-dimensional configurations that enhance attachment security to the sclera while distributing mechanical stress, utilizing curvature and folding rather than complex mechanical components
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 solution enables more efficient and stable electrical stimulation of the retina, reducing the risk of retinal damage and improving vision restoration by maintaining consistent pressure and minimizing edge trauma, thus enhancing the effectiveness of retinal prosthetics for patients with blindness from photoreceptor degenerative diseases.
Implementation Method 1
The array is made of a thermoplastic polymer that can be curved to match the shape of the retina
Data Source
AI summary
Polymer materials are useful as electrode array bodies for neural stimulation. They are particularly useful for retinal stimulation to create artificial vision, cochlear stimulation to create artificial hearing, and cortical stimulation, and many related purposes. The pressure applied against the retina, or other neural tissue, by an electrode array is critical. Too little pressure causes increased electrical resistance, along with electric field dispersion. Too much pressure may block blood flow. Common flexible circuit fabrication techniques generally require that a flexible circuit electrode array be made flat. Since neural tissue is almost never flat, a flat array will necessarily apply uneven pressure. Further, the edges of a flexible circuit polymer array may be sharp and cut the delicate neural tissue. By applying the right amount of heat to a completed array, a curve can be induced. With a thermoplastic polymer it may be further advantageous to repeatedly heat the flexible circuit in multiple molds, each with a decreasing radius. Further, it is advantageous to add material along the edges. It is further advantageous to provide a fold or twist in the flexible circuit array. Additional material may be added inside and outside the fold to promote a good seal with tissue.