Low power wearable system for vital signs measurement in all day long applications

In recent years, the demand for wearable devices has grown. This is due in large part to the ability to monitor in real time a critical state in the person´s health in all daily activities. However, such devices have not yet had a significant development. This is because of some technological aspects not yet fully consolidated. One of these aspects is the battery power supply that due to the weight and overall dimensions can prevent the movement and / or increase the invasiveness of the system. The present work describes an instrumented autonomous T-shirt adopting a low power circuit board consuming only 8.15 mA in run mode. The proposed low power wearable system can permit smaller and lighter batteries and continuous monitoring in all day long applications. The instrumented T-shirt is capable of measuring the frequency of respiration, heart rate and movement of the body, transmitting data to a readout unit and sending alarms if necessary. The methodology adopted, the design choices and the experimental results are clearly reported and discussed. The proposed methodology can be an effective solution for all wearable devices.