Myo Action: Accelerating Voluntary Actions via Electromyography and Muscle Stimulation

We propose a technique for accelerating users’ action without overriding intention, thereby preserving agency. In our approach, it is the user’s muscle signals, detected via electromyography (EMG), that trigger electrical-muscle-stimulation (EMS) without external sensors or stimulation-timing calibration. The key to enable this “agentic speedup” is a synergy between EMG and EMS: EMG can detect an early-onset of the neural-response; EMS can contract a muscle faster than a typical voluntary-contraction. This—coupled with our low-latency system (∼ 290 μ s)—results in an accelerated reaction-time, even though the haptic-assistance is initiated after the muscle-signal. In our study, we confirmed that our novel approach: (1) accelerated users’ reaction-time by ∼ 23 ms compared to voluntary-action; (2) preserved agency in decision-involving actions (i.e., go/no-go trials), which existing muscle-stimulation techniques cannot achieve; and (3) participants felt it augmented their performance in physical-tasks. This puts forward embodied-assistance that aligns with users’ decisions/intentions, which we demonstrate in exemplary applications.