mCardia: A Context-Aware ECG Collection System for Ambulatory Arrhythmia Screening

<jats:p> This article presents the design, technical implementation, and feasibility evaluation of <jats:bold> <jats:italic>mCardia</jats:italic> </jats:bold> —a context-aware, mobile <jats:bold>electrocardiogram</jats:bold> (ECG) collection system for longitudinal arrhythmia screening under free-living conditions. Along with ECG, <jats:bold> <jats:italic>mCardia</jats:italic> </jats:bold> also records active and passive contextual data, including patient-reported symptoms and physical activity. This contextual data can provide a more accurate understanding of what happens before, during, and after an arrhythmia event, thereby providing additional information in the diagnosis of arrhythmia. By using a plugin-based architecture for ECG and contextual sensing, <jats:bold> <jats:italic>mCardia</jats:italic> </jats:bold> is device-agnostic and can integrate with various wireless ECG devices and supports cross-platform deployment. We deployed the <jats:bold> <jats:italic>mCardia</jats:italic> </jats:bold> system in a feasibility study involving 24 patients who used the system over a two-week period. During the study, we observed high patient acceptance and compliance with a satisfactory yield of collected ECG and contextual data. The results demonstrate the high usability and feasibility of <jats:bold> <jats:italic>mCardia</jats:italic> </jats:bold> for longitudinal ambulatory monitoring under free-living conditions. The article also reports from two clinical cases, which demonstrate how a cardiologist can utilize the collected contextual data to improve the accuracy of arrhythmia analysis. Finally, the article discusses the lessons learned and the challenges found in the <jats:bold> <jats:italic>mCardia</jats:italic> </jats:bold> design and the feasibility study. </jats:p>