Lyfas uses photoplethysmography to detect blood volume changes and reflected light spectrum of blood chemistry in the microvascular bed of tissue, gathering vital functional biomarkers and parameters such as pulse rate variability, cardiac dynamics, autonomic nervous function, and vascular function. This allows for continuous assessment of phenotypic/functional markers of health and illness, which is non-invasive, personalized, and remote. It can be used as a risk and event prediction tool for life-threatening conditions like heart attacks and strokes, and also for chronic metabolic diseases like hypertension and diabetes. The data generated can help physicians work with patients towards supervised self-management of illness and restoring health and quality of life.