FAST OPTICAL SIGNAL / NON-INVASIVE NEUROIMAGING
The next era of computing.
We're building the first device designed from the ground up using the Fast Optical Signal to read neural activity with light. It's completely non-invasive, and works at the speed of neurons.
The next era of computing won't use fingers, thumbs, or voice — but your thoughts.
FAST OPTICAL SIGNAL
We read the brain with light.
When neurons become active, they briefly change shape. Ion and water movement across their membranes makes the cells swell by a small amount, and the surrounding tissue changes with it. That swelling changes how the tissue scatters near-infrared light; this allows us to measure neuronal activity optically in the moment it happens, rather than inferring it from blood flow several seconds later as traditionally done with fNIRS or fMRI.
Frequency-modulated infrared light is delivered to the scalp.
Photons travel through cortical tissue and back out.
Changes in the returning light show where activity happened, up to ~3 cm below the scalp.
below scalp
Today, the only devices that are portable,precise and fast require a hole in your skull.
Implanted electrodes work, but they require surgery. That limits them to patients with severe medical issues or paralysis, for whom the risk is worth it, not the billions of people who use a computer.
THE SPEC
Nothing else has all four things at once.
No surgery, no implant.
The whole cortex: motor, language, visual, decision-making, & more.
Millisecond timing, millimeter location.
Wearable, not a shielded room.
THE TRADE-OFF
FOS is fast, precise, high-coverage, and portable.
Fast optical signal was first demonstrated in humans in 1995. It's the only non-invasive method that delivers on all four of these elements: speed, precision, coverage, and portability.
| Modality | Speed | Spatial precision | Depth (from scalp) | Portable |
|---|---|---|---|---|
| EEG | ~1 ms | ~1–5 cm | Cortex, ~4 cm | yes |
| MEG | ~1 ms | ~2–5 mm | Cortex, ~4–5 cm | shielded room |
| fMRI | ~3–6 s | ~1–3 mm | Whole brain | fixed scanner |
| fNIRS | ~4–6 s | ~5–15 mm | Cortex, ~1–3 cm | yes |
| FOS | 5–10 ms | ~5–10 mm | Cortex, ~1–3 cm | yes |
Non-invasive modalities only. Figures are typical published ranges. Sources on the research page.
PUBLISHED STUDIES BY MODALITY
FOS has been hiding in plain sight
A method this good should not be this quiet. EEG, fMRI and fNIRS each grew into a robust field once the hardware was easy to work with. But since 1995, the Fast Optical Signal has been understudied given constraints on hardware, software, calibration time, and how tiny and fast the signal is. Now, thirty years after its first human demonstration, we're building the first commercial device designed specifically for FOS.
WHY SPEED MATTERS
The signal arrives even before any action.
In a simple reaction-time task, the optical response to a motor command appears about 96 ms before the button is pressed.
presented
detected
action
WHO'S BUILDING IT
Our CTO built the only commercial instrument sold for FOS measurement.
It was a modified fNIRS instrument, and it was never meant for FOS. We're building the first one designed for the job from the start, with a team across optics, electronics, firmware and neuroscience.
NOTES
What we're working on.
EVENTS
Where to find us.
Nothing on the calendar right now.
We speak at a handful of neurotechnology and optics meetings a year. Subscribe below and we'll say where.