Analysis of high-perimeter planar electrodes for efficient neural stimulation

Area of Science:

• Biomedical Engineering
• Neuroscience
• Electrical Engineering

Background:

• Planar electrodes are crucial for epidural spinal cord and cortical stimulation.
• Optimizing electrode geometry can improve neural stimulation efficiency and reduce power consumption.

Purpose of the Study:

• To investigate if increased current density variation on electrode surfaces enhances stimulation efficiency.
• To design and test novel high-perimeter planar electrode geometries.

Main Methods:

• Fabricated high-perimeter planar disk electrodes with sinuous variations, maintaining equal surface areas.
• Measured in vitro interface impedance across a range of frequencies.
• Utilized finite element modeling to analyze current density distribution.
• Quantified activation of 100 model axons at varying distances from electrodes.

Main Results:

• In vitro impedance measurements showed no significant difference between high-perimeter and circular electrodes.
• Finite element models confirmed higher current density variation on high-perimeter electrodes.
• High-perimeter electrodes demonstrated increased efficiency in activating axons at specific distances.

Conclusions:

• Electrode geometry significantly impacts neural stimulation efficiency.
• Novel high-perimeter planar electrode designs show promise for improving stimulation efficacy.
• This approach offers a feasible method to enhance neural stimulation through geometric optimization.