Is Ultra Sound Brain Stimulation Dangerous?

One of the open questions for ultra sound brain stimulation is, how long does the effect last? It looks like minutes to hours. But if you do multiple doses with an depressed participant, does that last for a week or two after we just don't know at this point. We are actually looking at dose response curbes as well. The nice thing about ultra sound is that we have a long history of imaging on the body,. from the fetus all the way up to the adult brain. So we know relatively well what the threshold is for danger.