Retinal Stimulation Biphasic Pulse Width Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing visual restoration aiding devices face challenges in determining appropriate electrical stimulation pulse signal parameters, such as pulse width and frequency, due to varying electrode placement positions, which affects the efficacy and safety of vision restoration.
Innovation Solution
A visual restoration aiding device with a signal generation unit placed on the outer side of the choroid, featuring a substrate with electrodes that apply biphasic rectangular wave electrical stimulation pulses, with pulse widths between 0.2 and 2 milliseconds, to induce and assist vision restoration by converting image data into electrical stimulation signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical stimulation parameters are adjusted for different electrode placement positions, then vision restoration efficacy is improved, but device complexity and parameter determination difficulty increase
Solution Approach 1:
The patent applies parameter changes by systematically varying electrical stimulation parameters (pulse width: 0.01-10 msec, pulse frequency: 1-100 Hz, voltage: 1-100 V) based on electrode placement position to optimize vision restoration efficacy while managing device complexity through defined parameter ranges
2Device complexity
If monophasic rectangular wave stimulation is used, then device simplicity is maintained, but safety and comfort are compromised due to potential tissue damage from charge accumulation
Solution Approach 1:
The patent applies periodic action by using biphasic rectangular wave stimulation where each phase (first positive, then negative) alternates in a periodic manner, ensuring charge balance and preventing tissue damage from charge accumulation while maintaining effective neural stimulation
Solution Approach 2:
The patent converts the potential harm of charge accumulation into benefit by using the second phase of opposite polarity to cancel out residual charges from the first phase, transforming what would be a harmful effect into a safety mechanism that protects retinal tissue
3Use of energy by moving object
If pulse width is reduced below 0.2 msec, then energy consumption decreases, but stimulation effectiveness and visual perception quality deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing pulse width within the range of 0.2-2 msec to achieve the optimal balance between energy consumption and visual perception quality, where parameters outside this range result in either excessive energy use or degraded visual output
4Area of stationary object
If pulse frequency is increased, then visual field coverage improves, but energy consumption and potential tissue stress increase
Solution Approach 1:
The patent applies parameter changes by optimizing pulse frequency within the range of 1-100 Hz to balance visual field coverage with energy consumption and tissue stress, where frequencies outside this range compromise either coverage or safety
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 device effectively applies safe and comfortable electrical stimulation to the retina, enabling patients to perceive phosphenes as bright, small, and sharply-outlined spots, enhancing vision restoration while minimizing invasive procedures and improving visual field coverage.
Implementation Method 1
a visual restoration aiding device for inducing and assisting restoration of vision by applying electrical stimulation (an electrical stimulation pulse signal) to cells constituting a retina from electrodes placed (implanted) in a body (an eye)
Data Source
AI summary
A visual restoration aiding device for restoring vision of a patient, comprises: a signal generation unit including a substrate to be placed on an outer side of a choroid of a patient's eye and a plurality of electrodes arranged on the substrate for applying electrical stimulation pulse signals to cells constituting a retina; a photographing unit which photographs an object to be recognized by the patient; and a processing unit which converts image data obtained by the photographing unit to data for electrical stimulation pulse signal and transmits the converted data to the signal generation unit: wherein, based on the data for electrical stimulation pulse signal transmitted from the processing unit, the signal generation unit forms a waveform of an electrical stimulation pulse signal to be outputted from each electrode into a biphasic rectangular wave including rectangular waves of opposite polarities, and sets a pulse width of the electrical stimulation pulse signal to 0.2 msec. or more and 2 msec. or less.