Retinal Implant Self-Testing via Wireless Impedance Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current retinal implant testing methods are inadequate for ensuring proper function before transplantation, and they struggle to reduce electrode impedance, limiting the effectiveness of stimulation current transfer to nerve tissue.
Innovation Solution
A system comprising an implantable device with pixel units and a conversion unit that uses a photoelectric sensor to output current, which is converted into a square wave voltage, and an amplification unit to determine the quality of the pixel units through wireless signal transmission, reducing impedance by cyclic voltammetry methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the retinal implant is hermetically sealed to prevent leakage current damage, then safety is improved, but testing capability deteriorates because no test point or electrode can be exposed
Solution Approach 1:
The patent introduces a conductive medium as an intermediary between the hermetically sealed implantable device and the external testing system. This medium allows electrical signal transmission through the sealed barrier, enabling testing without exposing internal electrodes or test points. The conductive medium acts as a mediator that bridges the isolation required for safety and the connectivity needed for testing.
2Ease of operation
If conventional testing methods are used, then testing can be performed, but functional assurance deteriorates because it is difficult to ensure proper function before transplantation
Solution Approach 1:
The patent enables preliminary testing and functional verification of the retinal implant before transplantation through wireless communication. The system allows complete functional testing, including pixel unit response to light stimulation and electrode impedance measurement, in advance of implantation. This preliminary action ensures functional assurance while maintaining ease of operation through automated wireless protocols.
Solution Approach 2:
The testing system incorporates feedback mechanisms where the implantable device responds to test stimuli and returns measurement data wirelessly. The system measures the response of pixel units to light source intensity changes and uses this feedback to determine quality metrics. This closed-loop feedback enables reliable functional assessment while keeping the testing process automated and easy to operate.
3Device complexity
If electrode impedance is not reduced, then the system is simpler, but stimulation effect deteriorates because impedance limits current transfer to nerve tissue
Solution Approach 1:
The patent applies preliminary electrode activation treatment through cyclic voltammetry before the implant enters normal operation. This preliminary action reduces electrode impedance by conditioning the electrode surface, thereby improving subsequent stimulation effectiveness. The activation process is automated and integrated into the initial setup, maintaining system simplicity while enhancing stimulation performance.
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
Enables self-testing of retinal implants before transplantation, reduces electrode impedance by over ten times, and simplifies the testing process with wireless signal decoding, saving power and circuit complexity.
Implementation Method 1
Each pixel unit includes a photoelectric sensor that receives illumination from a light source and outputs a current
Implementation Method 2
The amplification unit is electrically connected to the implantable device via the conductive medium
Data Source
AI summary
The present invention relates to a method for testing a retinal implant. After an implantable device for interfacing with retinal cells is provided, an external stimulus is applied to the implantable device so that the implantable device transmits a first pulse to a processing device through a wireless interface. When a conversion unit is controlled to gradually decrease an output voltage until the implantable device outputs an output voltage lower than a reference voltage, the implantable device transmits a signal different from the first pulse to the processing device through the wireless interface. The processing device determines a current value of a pixel unit according to a time difference between the first pulse and the signal.