Interesting project. Here's a thought which I've always had in the back of my mind, ever since I saw something similar in an episode of Buck Rogers (70s-80s)! Many people struggle with falling asleep due to persistent beta waves; natural theta predominance is needed but often delayed. Imagine an "INEXPENSIVE" smart sleep mask that facilitates sleep onset by inducing brain wave transitions from beta (wakeful, high-frequency) to alpha (8-13 Hz, relaxed) and then theta (4-8 Hz, stage 1 light sleep) via non-invasive stimulation. A solution could be a comfortable eye mask with integrated headphones (unintrusive) and EEG sensors.
It could use binaural beats or similar audio stimulation to "inject" alpha/theta frequencies externally, guiding the brain to a tipping point for abrupt sleep onset. Sensors would detect current waves; app-controlled audio ramps from alpha-inducing beats to theta, ensuring natural predominance. If it could be designed, it could accelerate sleep transition, improve quality, non-pharmacological.
Yeah, I'm sure that technology has existed for decades. Common folks just not allowed to know about it. It's "for our own good!" sarcastically speaking :(