The reliability and accuracy of a noncontact electrocardiograph system for screening purposes
BACKGROUND: Electrocardiography (ECG) requires the application of electrodes to the skin and often necessitates undressing. Capacitively coupled electrodes embedded in a normal chair would be a rational alternative for ECG screening. We evaluated the reliability and accuracy of ECG electrodes imbedded in a chair cushion. METHODS: Two independent clinicians compared ECG recordings obtained using skin electrodes with recordings obtained using capacitively coupled electrodes that were embedded in a chair cushion in an anesthesiology premedication room, a cardiology outpatient ward, and a cardiology day ward. We analyzed the data to compare the sensitivity and specificity for the diagnosis of cardiac arrhythmias. RESULTS: ECG recordings were obtained from 107 patients. Heart rate was accurately measured using the capacitively coupled electrodes, but motion artifacts made the identification of P and T waves unreliable. Signal quality was poor for patients with low body weight, patients wearing clothing containing mixed fibers, and patients wearing sweaty shirts. CONCLUSIONS: Heart rate was accurately measured, and some cardiac arrhythmias were correctly diagnosed using capacitive ECG electrodes. Capacitive electrodes embedded into an examination chair are a promising tool for preoperative screening. Improved artifact reduction algorithms are needed before capacitive electrodes will replace skin electrodes. Copyright © 2012 International Anesthesia Research Society.