The worry with cellphones in hospitals was twofold.

One, the signals from the older, higher power analog phones did cause disruption in sensitive computer circuits. This would cause interference with medical monitors, as most med monitors are specialized computers. As cell phones are now using much lower powered digital signals, this is no longer a concern.


Some hospitals use wireless systems, and there was minor concern about interference with the wireless systems in use. Completely different frequencies, not a problem.

Hence the lift of the ban.