Inductive sensing of air bubbles in intravenous fluids: A novel approach for patient safety

Abstract

In this study, a magnetic sensing approach is proposed for detecting air bubbles in intravenous fluids (IVs). To the author's knowledge, this is the first paper to apply magnetic sensing technology for the detection of air bubbles in an IV fluid. The approach is based on a compact, portable, and cost-effective sensor prototype that utilizes an LC resonator and a microcontroller. To validate the detecting system, an IV fluid containing air bubbles is passed through a medical tube, and the tube is passed over a planar coil. The magnetic interaction during the flow of the IV fluid with air bubbles is monitored and logging in real time. Air bubbles of 38, 44, 63 and 75 mm3 in IV fluid were successfully detected by the proposed sensing approach. Besides, the detection system is able to determine the flow direction, which is not encountered in alternatives such as capacitive sensing. The measurements from the established test setup, an average air bubble of 28 mm3 causes an inductance variation of approximately 2.8 nH.