Via photoplethysmography (PPG), red light and infrared LEDs can receive date from the environment and measure biometric data including heart rate, blood oxygen, blood pressure and blood sugar level. Adopting the sensing components to wearable devices enables a wider range of applications with many leading brands working on launching related products. (Image: Pixabay) A patent Apple received earlier this year describes how Apple Watch could analyze composition of water and determine the pH level of user’s sweat through the sensing components like short-wave infrared...