Travis is Director or Brain, Conciousness, & Cognition, at the Maharishi Internationial University in Fairfield, Iowa:

Which kind of EEG brain waves are induced by meditation?

Dr. Fred Travis: what happens in the brain when we meditate:

https://www.drfredtravis.com/videos.html

Travis uses an EEG cap and amplifiers from BIOSEMI:

https://www.biosemi.com/headcap.htm