Decoupling Cognitive Workload and Physical Motion Effects on Heart Rate Variability Using a Wearable Magnetocardiography Sensor

We have recently demonstrated a wearable MagnetoCardioGraphy (MCG) sensor capable of classifying high vs. low cognitive work, i.e., the amount of mental effort a person is exerting when performing a task during a given period of time. However, a major limitation of our previous work was the requirement to eliminate any type of motion for the participants. Here, we explore the effect of motion by employing three (3) different experimental setups, each with a different amount of physical motion and cognitive load exerted. To better understand the effect of motion, an inertial measurement unit (IMU) and a breathing rate sensor are employed in addition to the MCG sensor. Our results show that heart rate variability (HRV), demonstrated through the mean difference in duration between consecutive heartbeats, is at its highest when neither cognitive workload nor motion are exerted. HRV drops when the subject involves cognitive workload and motion. Our results pave the way for additional research in the field, with an utmost goal of catering to specific clinical applications.