Canadian Journal of Cardiology



      The Skiin Underwear is a wearable medical device in the form of undergarments that captures ECG signals using textile electrodes incorporated into a clothing item and transmits them via Bluetooth between a removable wearable pod and a companion app on a phone. The purpose of this clinical evaluation performed at a cardiology clinic was to compare the quality of the ECG collected using the textile electrodes in a population of older adults with suspected or diagnosed cardiac conditions.

      Methods and Results

      The assessment was performed using a Skiin Underwear band collecting 3 ECG channels with 5 electrodes: two right electrodes, two left electrodes, and one reference electrode (worn at the waist) concurrently the 12-lead ECG using gel adhesive single-use electrodes. Ten minutes recordings were collected with the patient supine and seated. One hundred participants were included: 63 males and 37 females, age of 63.6 ±10.4 years (42 to 86), BMI of 29.39 ±6.82 kg/m2, and waist circumference of 40.94 ±5.85 inches. 84 participants had Skiin and reference ECG that could be aligned for comparison. Non-readable ECG was attributed to participants having dry skin. Motion artifact was identified and excluded from the analysis. Proprietary Skiin R-peaks detection algorithm was used to identify individual QRS complexes on the ECG and remove ECG segments containing noise from analysis. The F1-score for QRS complexes detected using Skiin compared to the standard ECG was above 0.9 for 97% of participants while supine. This was numerically but not statistically better than with the patient sitting. Table 1 details F1-score and Recall for each channel and each position. There were no false-positives for R-peak detection outside of motion artifact segments. Forty three out of 84 participants had at least one arrhythmia labeled on the reference ECG, and Figure 1 illustrates how the Skiin ECG morphology and rhythm compare to the reference ECG.


      This is the first clinical assessment comparing performance of ECG collection using textile electrodes at the waist compared to the conventional ECG. With the static patient who is sitting or supine, textile electrodes reproduce detection of QRS complexes and arrhythmia with a great level of accuracy compared to the clinical standard.
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