Can it (or could it be made to in future iterations) record the sort of data used to produce the output of an ECG (echocardiogram)? That would be quite the application for people with actual or high risk for hear disease, I think?
ECG (electro- — not echo- — cardiogram) records electric potential changes between various points on the torso, of which pulse rate is really only a very averaged metric, obtained via blood flow and pressure changes.
No chance you'll detect a QT interval change with this.
