Suppression of cortical electrostimulation artifacts using pre-whitening and null projection

Area of Science:

• Neuroscience
• Biomedical Engineering
• Signal Processing

Background:

• Invasive brain-computer interfaces (BCIs) show potential for restoring motor function and sensation in paralyzed individuals.
• Cortical electrostimulation, used in BCIs, generates artifacts that interfere with neural signal recording.
• Existing hardware solutions are insufficient, necessitating effective back-end artifact suppression methods.

Purpose of the Study:

• To develop and evaluate a novel artifact suppression technique called pre-whitening and null projection (PWNP).
• To assess the efficacy of PWNP in reducing stimulation artifacts across different neural recording modalities (EEG, ECoG, MEA).

Main Methods:

• The PWNP technique was developed for artifact suppression in neural signals.
• PWNP was tested on electroencephalogram (EEG), electrocorticogram (ECoG), and microelectrode array (MEA) data from five human subjects.
• Performance was evaluated using signal-to-interference ratio (EEG) and interference index reduction (ECoG, MEA).

Main Results:

• PWNP achieved significant artifact suppression in EEG (32-34 dB increase in signal-to-interference ratio).
• In ECoG and MEA signals, PWNP reduced artifacts by 78-80% and 85%, respectively.
• PWNP outperformed independent component analysis (ICA) in artifact suppression and was simpler to implement.

Conclusions:

• PWNP is an effective and efficient method for suppressing stimulation artifacts in neural recordings.
• This technique facilitates simultaneous stimulation and recording in bi-directional BCIs.
• PWNP holds promise for biomimetically restoring motor function through advanced BCI systems.