Retinal Electrical Stimulation Feedback for Current Threshold Control

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Solution Overview

Problem

Existing methods for electrical stimulation of the eye to treat conditions such as macular degeneration face challenges in accurately delivering current density to target tissues, as current disperses through various tissues and is hard to control effectively.

Innovation Solution

A system and method using low-frequency pulse trains with monophasic or biphasic pulses, controlled by current or voltage, and monitored by patient-reported phosphenes to ensure target tissue stimulation, combined with a first electrode on the eye and a return electrode on the head, and a sensing electrode to adjust stimulation levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If transpalpebral electrical stimulation is used to treat retinal diseases, then the treatment can be non-invasive and easy to apply, but the current density at the target tissue is hard to control and may not reach the desired threshold

Engineering Contradiction:
Improveease of applicationVSAvoidcurrent density control
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements a feedback mechanism where the controller monitors the electrical stimulus parameters and adjusts them based on patient response. The system delivers a series of stimuli with increasing intensity and pauses between them to assess patient response, allowing real-time adjustment of current density to reach the desired threshold at the retinal target tissue while maintaining ease of application.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses dynamic adjustment of stimulation parameters including intensity, duration, and frequency of electrical pulses. The controller dynamically modifies these parameters during treatment based on patient feedback, enabling precise control of current density at the target tissue while maintaining the non-invasive transpalpebral application method.

Inventive Principle:
Principle #15Dynamics

2Reliability

If higher current amplitude is delivered at the eyelid to reach the stimulation threshold at target tissue, then the therapeutic effect is improved, but the risk of excessive stimulation and discomfort increases

Engineering Contradiction:
Improvetherapeutic effectivenessVSAvoidexcessive stimulation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs periodic electrical stimulation with controlled pulse trains delivered at specific frequencies and intervals. The controller delivers stimuli in series with pauses between them, allowing the tissue to recover and preventing excessive accumulation of stimulation effect. This periodic approach ensures therapeutic effectiveness while minimizing the risk of harmful over-stimulation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses feedback from patient response to adjust stimulation intensity in real-time. The controller monitors patient feedback during each pause between stimulus series and adjusts the current amplitude accordingly, ensuring the therapeutic threshold is reached without exceeding safe limits and causing discomfort or tissue damage.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If multiple electrodes are used to improve current distribution, then the stimulation coverage is enhanced, but the device complexity increases

Engineering Contradiction:
Improvecurrent distributionVSAvoidnumber of electrodes
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent divides the stimulation function into multiple electrodes with distinct roles: a first electrode (active) on the eyelid for delivering stimulation, a second electrode (reference) on the temple for completing the circuit, and a third electrode (sensing) on the eyelid for monitoring local electrical changes. This segmentation improves current distribution and targeting precision while keeping the overall device complexity manageable through clear functional separation.

Inventive Principle:
Principle #1Segmentation

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

Effectively delivers electrical stimulation to retinal tissues, avoiding excessive stimulation while restoring or maintaining vision by inducing phosphenes, and allowing for personalized treatment intensity adjustment.

Implementation Method 1

The basis of the therapeutic strategy may include stimulation of neurons along the visual pathway and/or non-neural tissue such as glial cells and epithelial cells

Methodology Applied
Scientific EffectElectrical stimulation: Electric Field

Implementation Method 2

monitored by patient-reported phosphenes to ensure target tissue stimulation

Methodology Applied
Scientific EffectPhosphene induction: Photoelectric Effect

Data Source

PatentEP4419189B1Method and system for eye treatment
Publication Date: 2025.12.24 I LUMEN SCI INC
  • EP4419189B1 patent drawingFigure 1A~1B
  • EP4419189B1 patent drawingFigure 1C
  • EP4419189B1 patent drawingFigure 2A

AI summary

Methods and systems including a first electrode substrate having one or more stimulation electrodes that are configured to apply electrical stimulation signals to a patient's first eye; a plurality of sensor electrodes configured to detect electrical activity from neural cells of the patient during delivery of an electrical-stimulation therapy, wherein the plurality of sensor electrodes includes a first sensor electrode and a second sensor electrode; a first return electrode configured to be placed in a location on the patient such that an electrical current is formed between at least one of the one or more stimulation electrodes and the first return electrode; and a stimulation controller configured to control the electrical current formed between the at least one of the one or more stimulation electrodes and the first return electrode such that the electrical current passes through a retina of the patient's first eye and delivers the electrical-stimulation therapy.