1. Recalibration of myoelectric control with active learning.
- Author
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Szymaniak, Katarzyna, Krasoulis, Agamemnon, and Nazarpour, Kianoush
- Subjects
ACTIVE learning ,MYOELECTRIC prosthesis ,PROSTHETICS ,LEARNING strategies ,STATISTICAL sampling ,LINEAR statistical models ,PIPELINE inspection - Abstract
Introduction: Improving the robustness of myoelectric control to work over many months without the need for recalibration could reduce prosthesis abandonment. Current approaches rely on post-hoc error detection to verify the certainty of a decoder's prediction using predefined threshold value. Since the decoder is fixed, the performance decline over time is inevitable. Other approaches such as supervised recalibration and unsupervised self- recalibration entail limitations in scaling up and computational resources. The objective of this paper is to study active learning as a scalable, human-in-the- loop framework, to improve the robustness of myoelectric control. Method: Active learning and linear discriminate analysis methods were used to create an iterative learning process, to modify decision boundaries based on changes in the data. We simulated a real-time scenario. We exploited least confidence, smallest margin and entropy reduction sampling strategies in single and batch-mode sample selection. Optimal batch-mode sampling was considered using ranked batch-mode active learning. Results: With only 3.2 min of data carefully selected by the active learner, the decoder outperforms random sampling by 4-5 and -2% for able-bodied and people with limb difference, respectively. We observed active learning strategies to systematically and significantly enhance the decoders adaptation while optimizing the amount of training data on a class-specific basis. Smallest margin and least confidence uncertainty were shown to be the most supreme. Discussion: We introduce for the first time active learning framework for long term adaptation in myoelectric control. This study simulates closed-loop environment in an offliine manner and proposes a pipeline for future real-time deployment. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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