Fractal Microelectrodes for More Energy-Efficient Cervical Vagus Nerve Stimulation

Area of Science:

• Biomedical Engineering
• Neuroscience
• Medical Devices

Background:

• Vagus nerve stimulation (VNS) holds therapeutic potential for peripheral dysfunctions.
• Traditional cuff electrodes for VNS can cause off-target effects.
• Microelectrodes offer selectivity but face challenges with impedance.

Purpose of the Study:

• To evaluate the efficacy of fractal microelectrodes for VNS.
• To compare the energy efficiency of fractal versus traditional circle microelectrodes in vivo.
• To investigate the potential of non-Euclidean geometries for VNS.

Main Methods:

• Fabrication of a thin-film device with both fractal and circle microelectrodes.
• In vivo testing in a rodent model (N=3).
• Comparison of neural stimulation performance at the same radial nerve coordinate.

Main Results:

• Fractal microelectrodes demonstrated superior energy efficiency.
• Activation of C-fibers using fractal electrodes required up to 52% less energy (p=0.012) compared to circle electrodes.
• This study is the first to show a geometric advantage for fractal microelectrodes in VNS.

Conclusions:

• Fractal microelectrodes represent a promising advancement for VNS.
• The geometric design of microelectrodes can significantly improve energy efficiency.
• This technology may mitigate off-target effects and enhance VNS treatment efficacy.