This paper is especially useful because it moves the wearable question from “what can these devices measure?” to “which type of wearable is actually most useful when I care about signal quality, movement, raw data and comfort at the same time?”
That is exactly where my project is now.
I am currently between a ring and a wrist-worn form, and I am also trying to decide whether the final sensing architecture really needs EDA + PPG / heart rate + accelerometry, with skin temperature as a possible secondary signal.
This study does not give me one universal “winner”, but it does make the trade-offs between devices much clearer.
Brandebusemeyer, Georgi and Arnrich compared four wearable systems:
The first study compared Shimmer3 GSR+, Empatica E4 and Pixel Watch 2 across baseline, cognitive-load, startle, relaxation and physical-activity conditions.
A second study then compared the older Empatica E4 with its successor, EmbracePlus, across selected cognitive, affective and relaxation conditions.
The paper looked at: