Zomato founder Deepinder Goyal introduces Temple, a ₹1 lakh head-worn wearable device

Zomato founder Deepinder Goyal is drawing attention for a new wearable device called Temple that attaches to the side of the head instead of the wrist to monitor brain blood flow. Goyal announced on X on Thursday, October 8, that pre-orders in India will open soon, with waitlist users getting priority. The device is expected to cost around ₹1 lakh, though the final price is not yet available. Temple is pill-shaped and designed to fit between the forehead and the ear. It is secured using disposable adhesive grips called Grips. The company states that these grips will last up to seven days, but recommends changing them every two to three days during sweating or dust exposure. Users can keep the device on during activities like running, swimming, and showering. The launch version will come in six colours including True Gold, Rose Gold, Black Mirror, Real Jade, Deep Blue, and Purple Funk.

Technology

Temple uses photoplethysmography, a technology common in smartwatches, but places the sensor near the temple instead of the wrist. The company calls this system BrainFlow. It monitors changes in cerebral blood flow to provide insights into sleep, recovery, exercise, and stress response. BrainFlow does not measure brain activity directly like an EEG, and Temple cannot diagnose medical conditions at this time. Goyal has published two preprint validation studies that have not yet been peer-reviewed. The first study involved 23 healthy adults, while the second involved 44 healthy men across 60 sessions. According to the shared results, BrainFlow showed correlations of up to 0.91 with changes in brain blood volume measured using time-domain near-infrared spectroscopy.

Future Uses and Limits

Goyal suggested that the applications could extend beyond fitness tracking, noting that he would like to have pilots wear it and that the Indian Air Force could potentially use it to determine fitness for missions. However, Temple is not an approved, established, or certified aviation safety device, and there is no evidence it can determine if a commercial pilot is medically fit to fly. Existing medical and regulatory procedures continue to govern aviation fitness. The company is also testing ideas for thought-to-text technology, though Goyal anticipates it will take several years.

Context

Wearable health technology has expanded rapidly beyond simple wrist bands into continuous physiological monitoring devices. While new sensors offer innovative ways to track bodily signals, they must undergo rigorous independent clinical validation and regulatory review before approval for high-stakes professional uses.