title: Concurrent Adaptation of Human and Machine Improves Simultaneous and Proportional Myoelectric Control.
abstract: Myoelectric control of a prosthetic hand with more than one degree of freedom (DoF) is challenging, and clinically available techniques require a sequential actuation of the DoFs. Simultaneous and proportional control of multiple DoFs is possible with regression-based approaches allowing for fluent and natural movements. Conventionally, the regressor is calibrated in an open-loop with training based on recorded data and the performance is evaluated subsequently. For individuals with amputation or congenital limb-deficiency who need to (re)learn how to generate suitable muscle contractions, this open-loop process may not be effective. We present a closed-loop real-time learning scheme in which both the user and the machine learn simultaneously to follow a common target. Experiments with ten able-bodied individuals show that this co-adaptive closed-loop learning strategy leads to significant performance improvements compared to a conventional open-loop training paradigm. Importantly, co-adaptive learning allowed two individuals with congenital deficiencies to perform simultaneous 2-D proportional control at levels comparable to the able-bodied individuals, despite having to a learn completely new and unfamiliar mapping from muscle activity to movement trajectories. To our knowledge, this is the first study which investigates man-machine co-adaptation for regression-based myoelectric control. The proposed training strategy has the potential to improve myographic prosthetic control in clinically relevant settings.
authors: Janne M
authors: JM
authors: Hahne
authors: Sven
authors: S
authors: Dahne
authors: Han-Jeong
authors: HJ
authors: Hwang
authors: Klaus-Robert
authors: KR
authors: Muller
authors: Lucas C
authors: LC
authors: Parra
mesh_terms: D002138:Calibration; D003199:Computer Systems; D004566:Electrodes; D004576:Electromyography / Q000295:instrumentation / Q000379:methods*; D006225:Hand; D006801:Humans; D007858:Learning; D016018:Least-Squares Analysis; D017880:Limb Deformities, Congenital / Q000534:rehabilitation; D009119:Muscle Contraction; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011597:Psychomotor Performance