Air flow estimation in the presence of motion artifacts

Provides a method to estimate occurrence of air flow even when large-amplitude motion artifacts occur. Simultaneously using several body-motion sensors with different measuring principles plus optimal placement for acquiring ventilation signals provides a high correlation of the signal components and a low correlation of the motion artifact components. We developed spatial averaging and multidimensional detection algorithms for ventilation monitoring to identify whether the signals acquired were from ventilatory efforts without air flow in the presence of body motion or from normal body motion with air flow. We sampled data from 14 adult male subjects according to a specific protocol. This study shows that signal crosscorrelation using a three-sensor system (one-impedance plus two-inductance sensors) can detect normal breathing, central apnea, the paroxysmal breathing caused by simulating obstructive apnea, and can estimate with a high probability whether air flow occurs during movement