A heated debate has erupted online after Dr Datta, a physician-scientist from AIIMS Delhi, strongly criticised Zomato Founder Deepinder Goyal’s new health-tech device, "Temple." The controversy began when Goyal wore the device on Raj Shamani's The Figuring Out Podcast, drawing attention to his latest venture into the medical technology space.
'Fancy toys billionaires can afford to waste money on'
Taking to X (formerly Twitter), Dr Datta wrote, "As a physician-scientist and one of the earliest researchers in India in Arterial Stiffness and Pulse Wave Velocity (2017), which predicts cardiovascular mortality, I can assure you that this device currently has 0 scientific standing as a useful device and do not waste your hard earned money to buy fancy toys billionaires can afford to waste money on. If you are one, then go ahead."
Check out the tweet below:
He expanded on his concerns in a thread, stating, "Also, mai hawa mein baat nahi karta, guys! We have tried variety of stuff in 2018, including trying to use AI for interpretation. On the basis of our research we applied for the Indian Innovation Growth Programme, and went to the Finals."
He continued, "Only cfPWV is a marker which can truly predict CV mortality. And accepted by scientific community. And you cannot just use the temporal artery as a surrogate because they aren’t reflective and has many confounding factors. What it is being repurposed now for is something you have to prove by doing year long studies! Till then sorry, my integrity as a researcher will make me call out pseudoscience wherever I see one!"
What is 'Temple' by Deepinder Goyal?
The device at the centre of the debate, called "Temple," is a specialised health-tech wearable developed by Deepinder Goyal, marking his entry into the deep-tech and medical research space. First revealed in December 2025, Temple aims to provide real-time, continuous monitoring of brain blood flow, a concept not yet widely addressed by consumer wearables.
Explaining the idea earlier on LinkedIn, Goyal described Temple as an "experimental device to calculate Brain Flow accurately." The device is closely tied to his ongoing personal research into what he calls the Gravity Ageing Hypothesis, a theory exploring how biological ageing could be influenced by gravitational and neurological factors. Continuous brain blood-flow tracking is critical to testing such hypotheses, especially when studying cognition, longevity and neurological health.
"Been using it for a year, and I've been feeling that this could shape into an important wearable the world needs. Brain Flow is already well accepted as a biomarker for ageing, longevity, and cognition. So, this device is useful and relevant even if the Gravity Ageing Hypothesis turns out to be wrong," Goyal wrote.
