Automatic Calibration of Electrode Arrays for Dexterous Neuroprostheses: a review.

Electrode arrays can simplify the modulation of shape, size, and position for 
customized stimulation delivery. However, the intricacy in achieving the desired outcome 
stems from optimizing for the myriad of possible electrode combinations and stimulation 
parameters to account for varying physiology across users.

Objective: This study reviews automated calibration algorithms that perform such an 
optimization to realize hand function tasks. Comparing such algorithms for their calibration 
effort, functional outcome, and clinical acceptance can aid with the development of better 
algorithms and address technological challenges in their implementation.

Methods: A systematic search was conducted across major electronic databases to identify 
relevant articles. The search yielded 36 suitable articles; among them, 14 articles that met the 
inclusion criteria were considered for the review.

Results: Studies have demonstrated the realization of several hand function tasks and 
individual digit control using automatic calibration algorithms. These algorithms significantly 
improved calibration time and functional outcomes across healthy and people with neurological 
deficits. Also, electrode profiling performed via automated algorithms was very similar to a 
trained rehabilitation expert. Additionally, emphasis must be given to collecting subject-specific a priori data to improve the optimization routine and simplify calibration effort.

Conclusion: With significantly shorter calibration time, delivering personalized stimulation, 
and obviating the need for an expert, automated algorithms demonstrate the potential for home-based rehabilitation for improved user independence and acceptance.