Hexagonal Mosaic Electrode Multiplexing for Retinal Prostheses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing retinal prostheses face challenges in achieving high visual acuity due to electrode interference, requiring a dense yet non-overlapping arrangement of electrodes, and inefficient multiplexing methods that complicate the configuration and delivery of stimulation signals.
Innovation Solution
The use of a hexagonal mosaic pattern for electrode array configuration allows for efficient multiplexing by minimizing configuration instructions and reducing the time required for stimulus delivery, enabling parallel stimulation through a novel addressing method based on the geometric shape of the hexagon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrodes are arranged at high density to improve visual acuity, then the number of phosphene per unit area increases, but electrode interference increases causing loss of discrete phosphene perception
Solution Approach 1:
The patent transitions from a conventional rectangular grid arrangement to a hexagonal mosaic arrangement, utilizing geometric dimensionality changes to optimize spatial distribution. This hexagonal tiling pattern allows electrodes to be positioned at the vertices of regular hexagons, creating a denser packing configuration that maximizes the number of electrodes per unit area while maintaining sufficient separation to avoid interference between adjacent electrodes.
2Adaptability or versatility
If a conventional multiplexing circuit is used to deliver stimulation signals, then current or voltage sources can be switched to electrodes, but the number of configuration instructions and time required increase
Solution Approach 1:
The patent implements a self-service addressing system where the hexagonal mosaic geometry itself encodes the addressing information. Each electrode position is uniquely identified by its location in the hexagonal grid, eliminating the need for complex external addressing codes. The geometric structure provides the addressing framework, allowing the system to configure and deliver stimuli to specific electrodes through simplified index-based instructions rather than elaborate configuration sequences.
3Quantity of substance
If electrodes are positioned close together to maximize density, then more phosphene can be generated, but the circular regions of activation overlap causing interference
Solution Approach 1:
The patent applies local quality optimization by positioning electrodes at the vertices of hexagons in a mosaic pattern, where each electrode's location is specifically optimized for its spatial relationship with neighboring electrodes. This arrangement ensures that while electrodes are densely packed to maximize phosphene generation, the geometric spacing maintains sufficient separation between adjacent electrodes to prevent charge interference, creating an optimal balance between density and interference avoidance.
Data Source
AI summary
A method is disclosed for efficient multiplexing of a plurality of electrodes in a nerve stimulator using improved, predetermined, regular, repeatable geometric patterns arranged in a predetermined mosaic to form a desired array. Multiple electrodes within said array are addressed by the nerve stimulator as being a stimulating electrode by an instruction specifying a single identifier, indicating a position within each regular geometric pattern. As such, each electrode within the array, maintaining the specified position within its respective repeatable geometric pattern, becomes a stimulating electrode and is connected to the appropriate electronic circuit for subsequent, potential use in nerve stimulation.