Can we invent new brain-computer interface modalities?
@raffi_hotter and I got 9 friends together and built a lab at home to test two totally new imaging methods: acoustoelectric imaging & functional ultrasound through the skull
๐งต story that involves nV measurements, pretty
.@raffi_hotter and I ran a 2-week hackathon investigating whether you could decode images from a portable brain scanner
We got initial results that suggest you can reconstruct images like these from brain activity recorded with time-domain NIRS, and share our detector prototype
The most cowboy path to BCI: spectral hole burning + ultrasound-modulated optical tomography
First apply ultrasound and light: the ultrasound tags photons that pass through a location on the brain with a small (1 MHz) color shift. Then โ *cryogenically* cool a crystal to 4 K and
We pursued acoustoelectric imaging and functional ultrasound since, in principle, you can get 1-mm resolution brain readings noninvasively.
Compared to EEG, thatโs ~10,000x the number of channels!
Just fixed Curius tonight and it should be available on the Chrome store again soon โ sorry to everyone who's been waiting! alas, we've been preoccupied with bci
It was exhilarating to wake up and constantly be thinking about the science, in an airbnb with friends
- making our own acoustic lenses out of candle wax, Orbeez, and carved... carrot molds
- new levels of jank, duct taping hydrophones to plastic straws
- buying 27 gallons of
Acoustoelectric imaging (AE) uses a physical phenomenon where ultrasound interacts with electric fields
Functional ultrasound was recently shown with the skull removed, but has yet to be shown with the skull intact
In the acoustoelectric effect, ultrasound interacts with electric fields by changing the conductivity of a material.
By applying ultrasound to a region, you can isolate signals from that region by looking for modulation at the ultrasound frequency โ typically > 500 kHz.