The Nerivio device from Israeli startup Theranica (see here previously) already has US FDA approval to treat acute migraines. It has now been approved for preventing migraines. Recent trials of 248 participants showed a huge improvement for those using Nerivio compared to those on a placebo device.

https://nocamels.com/2023/03/vibrating-armband-approved-for-migraine-prevention/

https://headachejournal.onlinelibrary.wiley.com/doi/10.1111/head.14469