Heart rate is one of the most basic and important indicators of health, providing a snapshot into a person's physical activity, stress and anxiety, hydration level, and more. Traditionally, measuring ...

Back in the 1940s, a Dutch physician called John Poel invented a device that changed the nature of heart monitoring. His device is based on the idea that the color of skin changes according to the ...

Heart rate is one of the most basic and important indicators of health, providing a snapshot into a person’s physical activity, stress and anxiety, hydration level, and more. Traditionally, measuring ...