Electrocardiogram Signal Quality Comparison Between a Dry Electrode and a Standard Wet Electrode over a Period of Extended Wear

The use of a dry electrode (DE), which does not rely on electrolytic solution, may circumvent potential disadvantages of a wet electrode (WE). The accuracy of the electrocardiogram (ECG) signal, provided by the electrode, is vital. The purpose of the study was to investigate if differences in signal quality, reflected by the signal-to-noise ratio (SNR), existed between the standard gel 3MTM Red DotTM 2560 electrode (WE) and the Orbital Research Incorporated (ORI) dry electrode (DE) over a 96 hour period of continuous wear. Assessments were made within electrode types, comparing potential signal deterioration within the electrode over time, and also between the two electrode types, comparing SNR over time. Twenty healthy adult volunteers completed the research protocol, each simultaneously wearing the two pairs of electrodes for 96 hours continuously in a lead II configuration. ECG tracings were collected simultaneously on different telemetry channels once a day over five consecutive days. The collection period consisted of six, three minute stages. The six stages included two bouts of rest, supine and standing, followed by three submaximal exercise stages, ending with one stage of standing rest. Data collected using the telemetry unit was de-noised by MatlabTM using sixth order Daubechies wavelet transform technology. No significant differences existed within the DE SNRs over time, indicating that SNR deterioration did not occur. Although a significant difference existed within the WE SNR between day 0 and 1 (17.83 ± 2.62 vs. 18.68 ± 2.35 on day 0 and day 1, respectively, p \u3c.01) in the standing stage, the noise was reduced therefore, SNR deterioration did not occur. The only significant difference (p \u3c .01) between the WE and DE SNRs occurred on day 2 (19.94 ± 2.11 vs. 18.73 ± 1.97) and day 4 (20.16 ± 2.16 vs. 18.96 ± 2.21) in the supine stage, favoring the WE. The difference observed could be attributed to a potential loss of skin contact when in the supine position. No differences