Low power wireless acquisition module for wearable health monitoring systems

This paper presents a low power wireless acquisition module for use within wearable health monitoring systems and Ambient Assisted Living applications. The acquisition module provides continuous monitoring of the user´s electrocardiogram (ECG) and activity, as well as the local temperature at the module. The module is placed on the chest of the user, and its wearability is achieved due to its fabrication based on a flexible PCB, and by the complete absence of connecting wires, as a result of the integration of flexible and dry ECG monitoring electrodes on the acquisition module, which do not require preparation with electrolyte gel. The design of the acquisition module also aimed for the minimization of power consumption to enable long-term continuous monitoring, namely concerning the wireless link, for which a proprietary low power solution was adopted. A low power analog frontend was custom designed for single-lead ECG monitoring, achieving a current consumption of 220 μA. The wireless acquisition module has a current consumption down to 1.3 mA while processing the acquisition of sensor data, and 4 mA when the wireless transceiver is active.