Insights on health technology, privacy-first design, and the science behind smarter wearables.
Most wearables score Monday morning as poor recovery when the real problem is that their algorithm does not know what time your brain thinks it is. Social jetlag shifts your circadian clock by one to two hours every weekend. The recovery score does not.
The Apple Watch measures electrical voltage. Every smart ring measures light bouncing off blood. These are two different physical phenomena, and the ring form factor makes ECG impossible with current technology.
Smart rings claim 'continuous' heart rate monitoring. The physics of photoplethysmography and a 20 milliamp-hour battery make that impossible. Here is the duty cycle nobody talks about, and why Pulsyn shows the gaps instead of hiding them.
Blood pressure is a force measurement, not a volume measurement. A PPG sensor in a smart ring tracks blood volume, not pressure. Here is why that gap cannot be closed with machine learning alone, and why Pulsyn will not ship a blood pressure estimate until the physics actually works.
Your smart ring does not measure sleep stages. It measures heart rate and motion, then guesses. Here's how the guess works, why the industry pretends otherwise, and why Pulsyn tells you the truth.
Your smart ring does not count your breaths. It counts the ripples that breathing leaves on your heart rate, then runs statistics to guess how many times you inhaled. The method is real. The precision is not.
When Intel shut down Basis in 2016, the devices did not break. The servers did. The cloud model turns your health history into a loan, and the company owns the vault. Pulsyn stores everything on your phone because your phone is the only hardware you actually own.
Most smart rings treat a 20-minute afternoon nap as either deep sleep or a complete miss. The reason is not a bug. It is a fundamental mismatch between how actigraphy guesses sleep stages and how naps actually work.
Most smart rings stop holding a full charge after 18 to 24 months, and the companies that sell them know it. The battery is sealed inside a titanium shell, glued shut, with no replacement path. That is not an accident. It is a business model.
