Maharishi was the Guru of the Beatles:

«Like no other, Maharishi combines Far Eastern spirituality with Western business acumen. Among the Hindu teachers in his homeland, it is frowned upon to charge money for spiritual tutoring. On the other hand, his students are also customers. In 1960 he offered courses in Germany for the first time; seven units of TM cost 200 marks. A few years later, 40,000 marks are due for the teacher’s course, the highest level of TM awareness. Running.

He opens new meditation centers all over the world and sometimes spends $80,000 on a device for measuring brain waves.»

https://www.spiegel.de/geschichte/maharishi-mahesh-yogi-guru-der-hippies-und-beatles-a-1190885.html

We suppose this was a BIOSEMI equipement with 256 EEG channels:

Dr. Fred Travis, neuroscientist & Cirector of the Center for Brain, Consciousness & Cognition Research at the Maharishi University, Fairfield, Iowa uses BIOSEMI products: if his budget allows

But all we know what is left of Maharishi’s meditation research project is Dr. Fred Travis neuroscientist & director of the Center for Brain, Consciousness and Cognition Research at the Maharishi University in Fairfield, Iowa:

Which kind of EEG brain waves are induced by meditation?