Sarah Constantin has been writing a series of posts about such technology (these aren't the only people trying it) over on her blog:
* https://sarahconstantin.substack.com/p/ultrasound-neuromodul...
* https://sarahconstantin.substack.com/p/how-ultrasound-neurom...
* https://sarahconstantin.substack.com/p/transcranial-ultrasou...
* https://sarahconstantin.substack.com/p/why-should-neuroenhan...
* https://sarahconstantin.substack.com/p/whos-working-on-ultra...