Design of wireless waist-mounted vital sensor node for athletes — Performance evaluation of microcontrollers suitable for signal processing of ECG signal at waist part

In recent years, the vital data of athletes during training and game have been used to plan effective training menus and avoid injuries and diseases, where a vital sensor node is often mounted at the chest position of an athlete. One of the main problems is that a tri-axis accelerometer sensor should be mounted at a different position such as rear waist for accurate energy expenditure (EE) estimation whereas an electro-cardio-gram (ECG) sensor should be separately mounted at a chest position for accurate heart rate (HR) estimation. In this paper, we newly design a wireless waist-mounted vital sensor node for both EE and HR estimations. First of all, to select a microcontroller suitable for the data processing in the vital sensor node, we numerically compared three microcontrollers in terms of energy consumption required for the vital data processing. The comparisons showed that LPC1768 is the most power-efficient candidate, so then we designed and implemented a prototype vital sensor node using LPC1768.