Exploring Potential of Electromyography-based Avatar Operation Using Residual Muscles of ALS Individuals: Case Study on Avatar DJ Performance

Assistive medical device, such as gastrostomy and ventilation, plays a crucial role in extending the lifespan of individuals with amyotrophic lateral sclerosis (ALS). Additionally, augmentative and alternative communication (AAC) systems are essential for maintaining their ability to communicate. Designing an effective AAC system requires balancing the user's expressive capability with the usability of the user interface. In this study, we focus on not gaze input and electroencephalograph (EEG) signal input commonly used in AAC systems but electromyography (EMG) signal input as a novel modality to augment their embodiment into a virtual space. Since EMG signals can be measured even with slight movements of residual muscles, EMG-based AAC systems provide a potential avenue for communication. We successfully demonstrated the feasibility of our EMG-based avatar communication system by enabling Masatane Muto, a DJ musician and creator living with ALS, to perform live remotely from Japan to the Ars Electronica Festival 2023 in Linz, Austria using the system. Through this case study and a pilot study, we aimed to explore the potential of EMG-based AAC systems by discussing three perspectives: augmented embodiment, prolonged use, and extensibility into real environments in diverse contexts.