Deepinder Goyal’s ‘Temple’ Wearable Shows First Signs of Tracking Brain Blood Flow – What the Early Study Means for Your Brain Health

When Deepinder Goyal, the Zomato founder, first flashed his sleek metal‑looking device on social media, most of us thought it was just another fashion‑forward smartwatch. Turns out, the gadget – called Temple – is trying to do something far more ambitious: it wants to keep an eye on the blood that flows through our brains.

In a modest pilot that involved 23 healthy volunteers, researchers placed the Temple sensor on the side of the head and asked participants to pedal on a stationary bike. While the cyclists worked up a sweat, the device logged its proprietary “Brain Flow” index, a number that supposedly reflects how fast blood is moving inside the skull.

To see if the reading meant anything, the team ran a side‑by‑side comparison with transcranial Doppler (TCD), a specialised ultrasound scan doctors use to measure velocity in the middle cerebral artery. The two sets of numbers moved in step with each other, yielding a correlation of about 0.8 – a figure that, while not perfect, is encouraging for a first‑time consumer gadget.

Don’t mistake that 0.8 for an 80 % accuracy claim, though. Correlation simply tells us the trends line up; it doesn’t guarantee the device is measuring the exact same thing as the medical scanner. After all, Temple’s sensors sit against the scalp, where blood in superficial vessels can also shift during exercise, potentially muddying the signal.

The study’s authors are quick to point out the limitations: a tiny sample size, only two test conditions (rest and post‑exercise), and a pre‑print that hasn’t yet survived peer review. In short, we’re looking at an early sketch, not a finished portrait of brain‑health monitoring.

What’s exciting, however, is the concept itself. If future work can tease apart scalp‑versus‑brain blood signals and prove that Temple can reliably flag meaningful changes – say, reduced cerebral perfusion in early dementia – we might have a low‑cost, everyday way to keep tabs on a crucial aspect of neurological health.

For now, Temple should be seen as a health‑tracking curiosity rather than a replacement for a doctor’s ultrasound. It may give you a daily “brain flow” score, but any concerning trend would still need validation with proper medical equipment.

Goyal has hinted that a limited pre‑order window will open soon, with shipments slated for before the end of 2026. Whether you’ll wear it for style points, curiosity, or genuine brain‑health insights remains to be seen – but the first data point certainly puts the idea on the scientific radar.