Explainer: What's on Deepinder Goyal's temple? All you need to know about gadget claiming to reverse ageing

Zomato founder Deepinder Goyal recently appeared on Raj Shamani's podcast. During the conversation, he spoke about various issues faced by Zomato delivery workers. He also rejected claims that delivery personnel are exploited or even put at risk due to the so-called 10-minute delivery rush, asserting that they face no pressure regarding timing.

Deepinder's podcast and insightful conversation not only refuted multiple claims of Zomato delivery workers being harassed, but also drew attention on social media when users noticed him wearing a small silver gadget just beside his right temple.

Temple is a lightweight, daily-wearable sensor developed under Goyal's ventures, including Eternal (Zomato's parent company) and Continue Research. Described by Deepinder Goyal as an experimental device to measure Brain Flow precisely, in real-time, and continuously, it tracks cerebral blood flow, a key biomarker linked to neurological wellbeing, cognition, ageing, and longevity.

However, researchers and start-ups are developing small optical and sensor patches that use techniques such as functional near-infrared spectroscopy (fNIRS), diffuse speckle contrast flow, or diffuse correlation spectroscopy (DCS) to estimate regional cerebral blood flow and oxygenation without surgery.

These approaches enable mobile tracking of brain perfusion and cognitive fatigue, with applications such as.

Monitoring focus and mental fatigue in students and professionals

Observing stress responses and emotional regulation

Detecting cognitive decline in the elderly

Optimising performance for athletes and high-performers.

Goyal has been personally testing the device for over a year, calling it a tool for preventive health in a world where staying healthy is hard and time-consuming.