MyoAction

Abstract

We propose a technique for accelerating users' actions 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 us), 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 and intentions, which we demonstrate in exemplary applications.