An Electrooculogram-Based Interaction Method and Its Music-on-Demand Application in a Virtual Reality Environment

Recently, the devices commonly used for interaction with a virtual reality (VR) environment include game controllers, data gloves, and motion tracking systems. However, these devices may limit the immersive experience or cause inconvenience, especially for patients with limb paralysis. This paper proposes a new nonmanual human-computer interface (HCI) based on a single-channel electrooculogram (EOG) signal and enables real-time interactions with the VR environment. The graphical user interface of the EOG-based HCI in VR includes several buttons flashing in a random order. The user needs to blink in synchrony with the corresponding button's flashes to issue a command, while the algorithm detects the eye blinks from the EOG signal and determines the users' target button. Furthermore, with the EOG-based HCI, we developed a music-on-demand system in the VR environment. By blinking, users can search and select target songs in the music library, play the selected songs, switch to the next song, and delete songs from the list. Ten healthy subjects and five patients with spinal cord injuries (SCIs) participated in online experiments. The experimental results demonstrated the effectiveness of the EOG-based HCI as a new method for interacting with the VR environment. Furthermore, the music-on-demand system can be used for entertainment not only by healthy people but also by SCI patients with limb paralysis.