Foveal-Stimulating Retinal Electrode Array With Central Void
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Solution Overview
Problem
Existing visual prostheses are unable to provide a controlled and effective stimulation of retinal cells to induce a realistic perception of light, as they are often bulky, lack precision, and fail to adequately simulate vision in visually impaired individuals due to inadequate electrode placement and distribution.
Innovation Solution
A retinal electrode array with a center section devoid of electrodes and a ring of small, high-density electrodes surrounding the fovea, with electrodes gradually increasing in size and spatial pitch moving away from the fovea, designed to maximize retinal response and control light perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a uniform electrode array is used across the retina, then the device structure is simple, but the stimulation precision and light perception control are insufficient
Solution Approach 1:
The patent applies local quality by varying electrode density and size across different retinal regions. The foveal region has no electrodes, while the parafoveal region has high-density small electrodes for precise stimulation, and peripheral regions have larger, more spaced electrodes. This non-uniform distribution optimizes stimulation precision for each specific retinal area's functional requirements.
Solution Approach 2:
The electrode array is segmented into distinct functional zones: a central foveal region without electrodes, a parafoveal ring with high-density electrodes, and peripheral regions with coarser electrode spacing. This segmentation allows each zone to be optimized for its specific visual function, improving overall stimulation precision while managing device complexity through modular zone design.
2Measurement precision
If electrodes are placed densely across the entire retina, then the coverage is high, but the foveal stimulation is compromised and light perception control is reduced
Solution Approach 1:
The patent extracts electrodes from the foveal region entirely, creating a electrode-free zone in the center. This extraction allows for precise control of light perception in the foveal area while maintaining electrode coverage in the parafoveal and peripheral regions. The removal of electrodes from the sensitive foveal zone prevents unwanted stimulation and enables better control over visual perception.
Solution Approach 2:
The electrode array implements local quality by having different electrode densities in different regions. The foveal region has zero electrode density for precise perception control, while the parafoveal region has high electrode density for broad coverage. This spatial variation in electrode quality allows simultaneous optimization of both coverage and perception control.
3Reliability
If the electrode array is made bulky to ensure stability, then the mechanical stability is improved, but the device cannot produce adequate simulated vision
Solution Approach 1:
The patent employs a flexible, thin-film electrode array that conforms to the retinal surface. This thin-film design provides adequate mechanical stability through flexibility and conformability rather than bulkiness, allowing the device to maintain stable contact with the retina while being thin enough to not interfere with visual perception or cause excessive compression.
Solution Approach 2:
The electrode array uses local quality by varying electrode size and spacing across different retinal zones. Small, densely packed electrodes in the parafoveal region provide precise stimulation for vision simulation, while larger, sparser electrodes in peripheral regions provide stable mechanical contact. This localized variation allows the device to achieve both stability and vision simulation capability.
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 electrode array enhances the precision and effectiveness of visual stimulation by optimizing electrode placement and distribution, allowing for a more controlled and realistic perception of light, improving the functionality of visual prostheses in aiding visually impaired individuals.
Implementation Method 1
Neural tissue can be artificially stimulated and activated by prosthetic devices that pass pulses of electrical current through electrodes on such a device. The passage of current causes changes in electrical potentials across visual neuronal membranes, which can initiate visual neuron action potentials
Data Source
AI summary
The present invention is an improved method of electrically stimulating percepts in a patient with a visual prosthesis, to induce a more controlled perception of light. In particular, the present invention is an improved electrode array to maximize retinal response. The array of the present invention is an array with a center section with no electrode, surrounded by a ring of small high density electrodes. Electrodes beyond to ring are gradually larger and more widely spaced.