Non-intrusive Wearables for health care are approaching its usability & maturity level associated to mathematical and artificial intelligence processing of the raw data.
That is the case of Trilobyte Statistial Software from the Checrepublic specialize in transforming photoplethysmography (PPG) and APPG (accelerated PPG) analysis together with Spectral frequency analysis and Heart pulse analysis into valuable parameters for health care control such as: HRV (heart rate variability), HRT (heart rate turbulence), oxygen saturation, blood pressure, cardiac output and respiration (sleep disorder breathing & Cheyne-Stokes breathing).
With those parameters we can calculate the risk analysis for cardiac failure and screen analysis for treatment.
Now-a-days those devices can continuosly monitor heart status with a wireless connection and furthermore can be fashionable. This is the case of the Oxirate(TM) proposal: