alt Hacker NewsIt doesn't work until it does.
The same thing has been said about robotics, AI, space travel, etc. etc.
I'm not saying this is the way, and I have significant questions of understanding thought based on reading brain activity, but I wouldn't put down the entire ultrasound field.
It doesn't work unless it does.
Until implies we're just waiting. Unless implies actual evidence, and - in medical procedures - some guarantee of safety.
SF6 plus ultrasound is used to open the blood brain barrier. So if you're pumping a lot of ultrasound into a brain and using a lot of SF6, there are already risks.