Artificial Retina Microcomputer Gain Control for Contrast Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current artificial retina systems, particularly the sub-retinal type, face challenges in achieving sufficient contrast sensitivity due to limited differences in current magnitudes generated by photodiode arrays, which impairs the ability to clearly distinguish objects from backgrounds, especially in patients with retinitis pigmentosa or age-related macular degeneration.
Innovation Solution
An artificial retina system that includes a microcomputer to compare the magnitudes of electric signals from photodiode cells with reference values, amplifying or attenuating these signals to enhance contrast sensitivity, utilizing a photodiode array with amplifiers and stimulation electrodes to control the gain of the electric signals, thereby improving visual cell stimulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the sub-retinal type artificial retina uses a photodiode array to stimulate visual cells, then the structure is simpler and fewer components are required, but the contrast sensitivity is insufficient due to limited differences in current magnitudes
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the gain of amplifiers associated with each photodiode cell. The microcomputer controls the amplification factor based on the magnitude of electric signals, transforming the uniform current output into variable current magnitudes that enhance contrast sensitivity. This resolves the contradiction by maintaining the simple sub-retinal structure while improving measurement precision through parameter adjustment.
Solution Approach 2:
The patent introduces dynamics by making the amplification factor variable rather than fixed. The microcomputer continuously adjusts the gain of each photodiode's amplifier based on real-time signal magnitude, enabling the system to adaptively enhance contrast. This dynamic adjustment resolves the contradiction between structural simplicity and contrast sensitivity by adding control flexibility without increasing physical complexity.
2Adaptability or versatility
If the epi-retinal type artificial retina is used with independently controllable electrodes, then the magnitude of electric stimulation can be freely changed, but the device complexity increases with more components and signal transmission units
Solution Approach 1:
The patent merges the photodiode array and stimulation electrode functions into a single sub-retinal implant structure. Instead of separating the camera, image processor, and electrodes as in epi-retinal systems, the patent integrates light sensing and electrical stimulation in one compact device, reducing component quantity while maintaining adaptability through electronic control.
Solution Approach 2:
The patent applies multi-functionality by making each photodiode cell serve dual purposes: detecting light and generating stimulation current. The same photodiode array that captures visual information also directly stimulates the visual cells after amplification, eliminating the need for separate sensing and actuation components. This resolves the contradiction by reducing device complexity while preserving adaptability through the microcomputer-controlled amplification system.
3Device complexity
If the photodiode array generates electric signals with limited current magnitude differences, then the structure remains simple, but the ability to distinguish objects from backgrounds is impaired
Solution Approach 1:
The patent implements feedback by using the microcomputer to monitor the magnitude of electric signals from each photodiode and adjust the amplifier gain accordingly. The system feeds back the signal magnitude information to control the amplification level, enhancing the distinction between objects and backgrounds. This resolves the contradiction by maintaining simple signal processing structure while preventing information loss through adaptive feedback control.
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 system significantly improves contrast sensitivity, allowing patients to perceive clearer interfaces between background and objects, minimizing cross-talk phenomena, and providing optimal resolution by adjusting the gain of the amplifier based on signal comparisons.
Implementation Method 1
a photodiode 111 that converts light introduced from outside into an electric signal and outputs the electric signal
Implementation Method 2
an amplifier 113 that amplifies or attenuates the electric signal output from the copier 112, and a stimulation electrode 115 that stimulates the visual cells with the electric signal output from the amplifier 113
Data Source
Figure 1
Figure 2
Figure 3(a)~4
AI summary
Provided is an artificial retina system for improving contrast sensitivity. The artificial retina system, according to one embodiment of the present invention, comprises: an artificial retina (100) which is installed under the retina and includes a plurality of photodiode cells (110); and a microcomputer (200) for comparing, with at least one reference value, the magnitude of an electric signal outputted from a photodiode 111 in each of the photodiode cells (110), and controlling to amplify or reduce the electric signal outputted by each of the photodiode cells (110) according to the result of comparison, wherein visual cells corresponding to each of the photodiode cells (110) can be stimulated with an electric signal controlled by the microcomputer (200).