Design and performance evaluation of a real-time single-channel ear-EEG acquisition system for wearable applications*

Ear-EEG, as a special type of signal collected within the ear canal, offers advantages such as a relatively enclosed acquisition environment and reduced susceptibility to motion artifacts. Its signal-to-noise ratio is comparable to that of scalp EEG. However, its amplitude is generally lower, and the high energy consumption of previous devices has limited its long-term use. Additionally, the multi-channel acquisition method has increased the time required for electrode configuration, complicating the acquisition process. More importantly, past research has predominantly focused on the electrodes themselves, lacking the development of a complete acquisition system. These factors have restricted the widespread application of ear-EEG. To address these issues, this paper aims to develop a low-power, low-noise, real-time single-channel ear-EEG acquisition system. The system employs an integrated design, incorporating universal acquisition electrodes, a miniaturized wearable device for signal acquisition, processing, and transmission, and accompanying software for real-time data display and storage. This ensures convenient daily wear, enhances user experience, and improves the efficiency and quality of ear-EEG acquisition. Three experiments were designed to validate the system: a signal-to-noise ratio test, an alpha wave eye-opening and closing test, and an auditory steady-state response test, demonstrating its application value in scenarios requiring high signal quality, such as medical diagnosis and health monitoring.Clinical RelevanceThis system is designed for real-time monitoring of human ear-EEG signals. It not only ensures the accuracy of signal acquisition but also significantly enhances the concealment and convenience of use. In healthcare scenarios, the system helps address privacy concerns that patients may encounter when wearing medical devices outside the hospital, making daily medical monitoring and personalized health services feasible.