Title: Dictionary-based Monitoring of Premature Ventricular Contractions: An Ultra-Low-Cost Point-of-Care Service,
Abstract: While cardiovascular diseases (CVDs) are prevalent across economic strata,
the economically disadvantaged population is disproportionately affected due to
the high cost of traditional CVD management. Accordingly, developing an
ultra-low-cost alternative, affordable even to groups at the bottom of the
economic pyramid, has emerged as a societal imperative. Against this backdrop,
we propose an inexpensive yet accurate home-based electrocardiogram(ECG)
monitoring service. Specifically, we seek to provide point-of-care monitoring
of premature ventricular contractions (PVCs), high frequency of which could
indicate the onset of potentially fatal arrhythmia. Note that a traditional
telecardiology system acquires the ECG, transmits it to a professional
diagnostic centre without processing, and nearly achieves the diagnostic
accuracy of a bedside setup, albeit at high bandwidth cost. In this context, we
aim at reducing cost without significantly sacrificing reliability. To this
end, we develop a dictionary-based algorithm that detects with high sensitivity
the anomalous beats only which are then transmitted. We further compress those
transmitted beats using class-specific dictionaries subject to suitable
reconstruction/diagnostic fidelity. Such a scheme would not only reduce the
overall bandwidth requirement, but also localising anomalous beats, thereby
reducing physicians' burden. Finally, using Monte Carlo cross validation on
MIT/BIH arrhythmia database, we evaluate the performance of the proposed
system. In particular, with a sensitivity target of at most one undetected PVC
in one hundred beats, and a percentage root mean squared difference less than
9% (a clinically acceptable level of fidelity), we achieved about 99.15%
reduction in bandwidth cost, equivalent to 118-fold savings over traditional
telecardiology.