Long-term functionality of a soft electrode array for epidural spinal cord stimulation in a minipig model

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Long-term performance of neural interfaces depends on implant material properties.
• Soft implant materials are being explored to reduce immune response compared to hard materials.

Purpose of the Study:

• To assess the 6-month in-vivo performance of a soft electrode array in the spinal epidural space.
• To evaluate the biointegration and stability of soft neural electrodes for potential therapeutic applications.

Main Methods:

• A soft electrode array with platinum-silicone contacts and gold interconnects was implanted in minipigs.
• In-vivo electrode impedance and voltage transients were monitored for 6 months.
• Epidural stimulation was performed to assess functional responses.

Main Results:

• The soft electrode array facilitated muscle-specific evoked potentials and contractions post-implantation.
• Changes in electrode impedance were observed over the 6-month study period.
• These impedance changes were influenced by postoperative factors and stimulation.

Conclusions:

• Soft implantable electrodes show promise for spinal epidural interfacing.
• Understanding impedance changes is crucial for improving the long-term stability of soft neural electrodes.
• Further research can optimize soft electrode design for reliable neural interfacing.