2.4 GHz BLE-based Smart Sensing System for Remote Monitoring of Health, Safety and Comfort at Workplace

In this paper a smart sensing system is proposed with the aim of improving health, safety, and comfort of workers. Different innovative sensors are integrated into a unique board to collect data referred to the physiological state. A remote Bluetooth Low Energy (BLE) interface is used to transmit the extracted parameters to a monitoring mobile App. Main assessments of worker conditions include measurements of heart rate, blood oxygen saturation, skin temperature, vibration, and motion levels. Vital parameters of heart rate and blood oxygen saturation are obtained from processing red and infrared signals detected by means of an accurate photoplethysmography (PPG) sensor. For the sake of evaluating the body temperature, a non-invasive sensor is put in contact directly with the skin. The skin temperature varies at different locations and the used sensor allows the small differences to be appreciated. In addition to vital parameters, an indicator of human motion that relates to fatigue and working stress is extracted through an Inertial Measurement Unit (IMU) from which the root mean square (RMS) of acceleration signals is obtained. Since the IMU is suitably positioned on the final board, it also provides the correct worker posture to alert in case of incorrect situations.