22 posts found
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.
Most wearables give you a health age or body age score that compares your biometrics to a population average. The math is a regression model, not a medical diagnosis. Pulsyn does not show one because the number is statistically invalid for the individual reading it.
Most smart ring manufacturers advertise 7-day battery life. That number comes from a test mode where the heart rate monitor is off and the wearer is asleep. In real use, the gap between marketing and physics is about 40 percent.
Your fitness tracker data is not protected by HIPAA. The FTC, Congress, and 20 states are trying to fix that, but legislation only regulates what companies can do with data they already possess. Pulsyn removes the server entirely.
Most wearables report resting heart rate as the lowest heart rate they can find, usually during sleep. The clinical definition is different. Pulsyn measures it during motionless awake periods, and the gap between the two definitions is often 10 to 15 beats per minute.
Smart rings promise workout tracking, but the physics of finger blood flow makes PPG nearly useless during exercise. Here is why the heart rate data is often fabricated, and why Pulsyn does not pretend otherwise.
A Reddit post called Cracked Oura hit 769 upvotes by showing how to bypass Oura's mandatory subscription using raw BLE data. The thread turned into a product support forum for a product Oura refused to build.
