RFID tag antenna based wireless sensing method for medical transfusion applications

Real-time fluid-level monitoring in a medical transfusion procedure is very important for the safety and satisfaction of patients in hospitals. Traditional approaches rely on either the regular check by hospital staffs or the self-monitoring by patients. In this paper, a RFID based approach to automatically monitor the fluid level is introduced, where a passive and low cost tag is attached to a transfusion bag/bottle, and a center reader records the minimum transmitted power to activate the tag. The fluid level in a transfusion bag/bottle is then derived from the transmitted power level. Various experiments have been conducted to demonstrate the proposed method, including the tag orientations, bag/bottle rotation angles, and continuous fluid level changes. The measured data validate the feasibility of the wireless sensing approach.