Decoding continuous three-dimensional hand trajectories from epidural electrocorticographic signals in Japanese...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Rehabilitation Technology

Background:

• Brain-machine interfaces (BMIs) aim to restore function for individuals with movement impairments.
• Subdural electrocorticography (sECoG) offers accurate brain signal decoding but carries surgical risks.
• Epidural electrocorticography (eECoG) is less invasive, but its suitability for decoding natural movements remains uncertain.

Purpose of the Study:

• To investigate the feasibility of decoding continuous three-dimensional hand trajectories using epidural electrocorticography (eECoG) signals.
• To assess the long-term stability and performance of eECoG-based decoding models for brain-machine interfaces.

Main Methods:

• Continuous three-dimensional hand trajectories were decoded from epidural electrocorticography (eECoG) signals recorded from Japanese macaques.
• The stability of acquired movement information and the longevity of decoding models were evaluated over several months and days, respectively.
• Decoding performance was compared against previous subdural electrocorticography (sECoG) studies, accounting for signal artifacts.

Main Results:

• Successful decoding of continuous hand trajectories from eECoG signals was achieved.
• A stable quantity of information for hand movements was acquired for several months.
• Decoding models maintained accuracy for approximately 10 days without significant recalibration, despite chewing artifacts impacting correlation coefficients compared to sECoG.

Conclusions:

• Epidural electrocorticography (eECoG) provides an acceptable level of performance for decoding natural movements, despite lower correlation coefficients than sECoG due to artifacts.
• As a safer invasive recording method, eECoG is a promising candidate for long-term, real-life brain-machine interface applications.
• The potential for easy replacement and upgrades makes eECoG systems a strong contender for future BMI development.