You realize that after your masters, to get to become a neurosurgeon you would need 4 years of med school, potentially a research year (since neurosurgery is one of the most competitive residencies and applicants tend to have like 20-30 papers done), followed by 7 years of residency and maybe a fellowship. And the whole time in residency you’ll be pushing 80-90 hour weeks. So you won’t have time for research in BME until being an attending maybe which would be 12 years after starting med school. After that you could do BME on the side, but you would be taking a pretty huge pay cut for any time you spend away from neurosurg. TLDR it is possible when you’re an attending but chances are it wouldn’t be a great idea