Dokkyo Medical University is a private university in Mibu, Tochigi, Japan, established in 1973. Dokkyo University is located in the town of Mibu, in Tochigi Prefecture, about 1.5 hours north of Tokyo by train. From Wikipedia
Aprilia says he was flown to Dokkyo Medical University for a CT scan following Turn 1 contact with team-mate Marco Bezzecchi.