Ultrasound-Compatible Electrode for Functional Electrical Stimulation

Area of Science:

• Biomedical Engineering
• Neurorehabilitation
• Medical Imaging

Background:

• Functional electrical stimulation (FES) aids neurorehabilitation but can cause muscle fatigue, requiring monitoring.
• Ultrasound (US) imaging assesses FES-induced muscle changes, but conventional electrodes obstruct visualization.
• Existing FES electrodes lack ultrasound transparency, limiting real-time monitoring beneath the electrode site.

Purpose of the Study:

• To develop and evaluate novel body-conforming ultrasound-compatible FES (US-FES) electrodes.
• To compare the performance and US compatibility of the new US-FES electrodes against commercial hydrogel electrodes.
• To assess the potential of US-FES electrodes for real-time muscle activity monitoring during FES.

Main Methods:

• Fabrication of body-conforming US-FES electrodes using a silver nanowire/polydimethylsiloxane (AgNW/PDMS) composite.
• Performance comparison (conductivity, FES efficacy) between US-FES and commercial hydrogel electrodes.
• Ultrasound compatibility testing using phantoms and in vivo models during FES application.

Main Results:

• The developed US-FES electrodes demonstrated comparable conductivity and FES performance to commercial electrodes.
• US-FES electrodes showed significant ultrasound compatibility during FES, unlike commercial electrodes.
• Phantom and in vivo tests confirmed the feasibility of real-time muscle monitoring with US-FES electrodes.

Conclusions:

• Specially designed US-FES electrodes are effective and compatible with ultrasound imaging.
• These electrodes overcome limitations of conventional FES electrodes for monitoring.
• US-FES technology shows promise for enhanced neurorehabilitation and clinical applications.