Temporal Variation in telemonitoring data: on the Effect of Medication and Lifestyle Compliance

In a telemonitoring system, recording vital signs for heart failure patients, a temporal variation is observed in vital signs (blood pressure and heart rate), which may be attributed to various reasons, with medication incompliance or diet changes among the most important ones. This work aims at investigating the difference in vitals that is induced by medication intake, delays and omissions, combined with a high or low salt diet. Experimental data were collected from heart failure (HF) subjects and include multiple measurements within a day, under different activities. These recordings were repeated on four separate days, each under different salt and medication intake conditions. The data were analysed by generating features that express temporal intra-subject differences. Statistical analysis for each feature highlighted the importance of blood pressure while standing and before exercise. Classifiers were built, that can distinguish with 80% accuracy the short term medication effect, or incompliance, from variation after medication intake. This quantitative characterization of the temporal vital sign variation, with respect to activities, medication and diet changes could contribute to an effectiveness and compliance model in daily life conditions.