raffihotter

Thanks for sharing this! Linked it on the website.

I added an explanation to the page! Hope it's helpful.

fixed! sorry about that, and thanks for the feedback

Hmm, looking into this.

You don’t. The bubbles only form once the skull is outside the body. When it gets out of the body, the gaps that used to be filled with water get filled with air.

To my knowledge, transcranial doppler doesn’t form images. It just gives you a single channel measurement that is very low resolution.

The method we’re proposing would have mm resolution.

Precisely

Thanks for your questions! I was one of the people who worked on the project. To answer your questions:

> Is it fair to say that their claims about spatial resolution being >>> existing EEG options are jumping the gun? If I understand correctly, you need to be targeting individual 1mm^2 regions with individual acoustic lenses, which means 17,000 channels would required 17,000 separate, uniquely-tuned ultrasound emitters, yes? Even if that's possible without messing up the data (the MHz range is big, but is it that big?) it seems like a trivial impossibility to fit that in one headset -- even the standard 32-64 EEG channels alone seem like a long shot. But maybe I'm overly cynical, or one emitter could be used to usefully excite multiple regions at once?

Since the system is linear, you could use a single probe to focus at multiple spots. Each focus would be at a slightly different modulation frequency.

> Another oddity in that paper is that it reads like we're trying to find persistent signals in the brain, like a needle in a haystack, whereas my understanding was that the field is moving decisively towards tracking signal changes over time in a given region. Is my intuition correct that accounting for a moving target would add considerable complexity to this approach?

This method would indeed let you track signals that change over time. Lock-in-amplifiers can output time-varying signals.