J Biophotonics. 2022 Aug 27:e202200187. doi: 10.1002/jbio.202200187. Online ahead of print.
Photoplethysmography (PPG) is a noninvasive optical technology, with applications including vital sign extraction and patient monitoring. The PPG acquisition skin type may be of importance. Skin is either non-glabrous (~90%) or glabrous (~10%). Clinical PPG collection is typically from glabrous (fingerpad), while proliferating wearables collecting PPG, which may perform critical functions like arrythmia detection, often acquire from atypical sites. Glabrous skin has significant differences from non-glabrous, including microcirculation, yet comparisons between their PPG signals have not been well reported. Using a smartphone-based remote/contactless PPG, a pilot dataset was collected from the hands (palmar/dorsal) of 5 healthy volunteers. The data shows statistically significant lead time (52±36ms) of glabrous over non-glabrous. Further, a trend of glabrous amplitude increase over non-glabrous (31%) was found. Although our study has a small number of participants, these results further the characterization of PPG skin differences, and can be used to inform development of PPG-based devices. This article is protected by copyright. All rights reserved.