Yeah, that first 1973 gadget was basically the prototype for today’s smart wearables. Back then they were just measuring a pulse with a simple coil and a little display—no GPS, no AI. But the core idea was the same: capture raw physiological data, process it in real time, and feed it back to the user so they could tweak their training or recovery. Those early models laid down the feedback loop that modern biohacking tech expands into multisensor data streams, predictive analytics, and even autonomous adjustments. So when you look at a fancy wrist‑watch today, you’re seeing a hundred‑fold upgrade on the same foundational concept. If you want to push that further, just combine it with cold exposure, micro‑dosing, or even transcranial stimulation—no limits.