Location verification algorithm of wearable sensors for wireless body area networks

BACKGROUND: Knowledge of the location of sensor devices is crucial for many medical applications of wireless body area networks, as wearable sensors are designed to monitor vital signs of a patient while the wearer still has the freedom of movement. However, clinicians or patients can misplace the wearable sensors, thereby causing a mismatch between their physical locations and their correct target positions. An error of more than a few centimeters raises the risk of mistreating patients. OBJECTIVE: The present study aims to develop a scheme to calculate and detect the position of wearable sensors without beacon nodes. METHODS: A new scheme was proposed to verify the location of wearable sensors mounted on the patient's body by inferring differences in atmospheric air pressure and received signal strength indication measurements from wearable sensors. Extensive two-sample t tests were performed to validate the proposed scheme. RESULTS: The proposed scheme could easily recognize a 30-cm horizontal body range and a 65-cm vertical body range to correctly perform sensor localization and limb identification. CONCLUSIONS: All experiments indicate that the scheme is suitable for identifying wearable sensor positions in an indoor environment.