Evaluation of a textile-based wearable system for the electrocardiogram monitoring in cardiac patients

Abstract

We developed a textile-based wearable system, named MagIC, for the unobtrusive monitoring of one electrocardiogram (ECG) lead, respiratory frequency and motion. In the present study, we investigated the ability of this system to monitor cardiac rhythm and arrhythmic events in cardiac patients. The study was carried out by comparing ECG tracings simultaneously recorded by MagIC and traditional ECG devices (Trad-ECG) in 40 cardiac patients at rest and during physical exercise. Data were manually scored by two cardiologists. At rest the artefact rates observed with MagIC and Trad-ECG were virtually identical (1.4% of the registered signal); while during physical exercise the artefact rate observed with MagIC was much lower than with Trad-ECG (4.07 vs. 17.31%). Recordings from MagIC allowed a correct identification of the type of rhythm in the vast majority of patients (92.5%) and an estimation of PQ interval and QRS duration similar to Trad-ECG (<0.016 s). MagIC displayed a good performance in detecting arrhythmias, with only 14 misclassified events out of 3618, and both specificity and sensitivity being above 99%. No practical difference was observed in the estimation of the beat-by-beat RR interval by the two methods. This study indicates that in static condition MagIC has a capability of monitoring cardiac rhythm and arrhythmic events which is comparable with what obtainable by a traditional one-lead ECG recorder. During movement MagIC provides an ECG signal of better quality.