Signal Quality Assessment of a Novel ECG Electrode for Motion Artifact Reduction

Abstract

Background: The presence of noise is problematic in the analysis and interpretation of the ECG, especially in ambulatory monitoring. Restricting the analysis to high-quality signal segments only comes with the risk of excluding significant arrhythmia episodes. Therefore, the development of novel electrode technology, robust to noise, continues to be warranted.

Methods: The signal quality of a novel wet ECG electrode (Piotrode) is assessed and compared to a commercially available, commonly used electrode (Ambu). The assessment involves indices of QRS detection and atrial fibrillation detection performance, as well as signal quality indices (ensemble standard deviation and time-frequency repeatability), computed from ECGs recorded simultaneously from 20 healthy subjects performing everyday activities.

Results: The QRS detection performance using the Piotrode was considerably better than when using the Ambu, especially for running but also for lighter activities. The two signal quality indices demonstrated similar trends: the gap in quality became increasingly larger as the subjects became increasingly more active.

Conclusions: The novel wet ECG electrode produces signals with less motion artifacts, thereby offering the potential to reduce the review burden, and accordingly the cost, associated with ambulatory monitoring.

Keywords: motion artifacts; signal quality assessment; wet ECG electrode.

Figure 1

The Ambu BlueSensor L (left) and the Piotrode electrode (right).

Figure 2

Lead placement for recording two simultaneous single-lead ECGs (lead AI). The two electrodes for comparison are positioned as closely to each other as possible at the positions A and I. The same ground electrode is used for both electrodes.

Figure 3

QRS detection performance: mean and standard deviation of (a) sensitivity and (b) positive predictive value of the Piotrode (blue) and the Ambu (red) electrodes.

Figure 4

AF detection false positive rates during running, sorted in ascending order, for the Ambu electrode. The false positive rate for the Piotrode electrode was 0.0% in all subjects.

Figure 5

An example of signal recorded simultaneously during running using (a) the Piotrode and (b) the Ambu electrodes.

Figure 6

Mean and standard deviation of (a) ${\overline{\sigma }}_e$ and (b) $\overline{\rho }$ for the Piotrode (blue) and the Ambu (red) electrodes.

Figure 7

An example of signal recorded simultaneously during undressing and dressing using (a) the Piotrode and (b) the Ambu electrodes.