Samsung's Galaxy S5 is supposed to be able to measure stress, but there's something about its "heart-rate variability" test that just isn't very convincing. (Namely, if you enjoy a brisk walk and raise your heart-rate slightly, the phone will sometimes report an increase in "stress.") By contrast, a new hip-worn sensor called "Spire" ignores your pulse in favor of monitoring breathing patterns instead. Its creators claim that these patterns can reveal periods of "tension, relaxation and focus," as well as allowing standard fitness tracking.Until we get the chance to review the Spire, we can't say for sure if it'll be any more meaningful than Samsung's approach -- but it's at least backed up by science (and funding) from Stanford University. (Besides, from a purely selfish tech blogger's perspective, some detailed mental analysis could be a nice distraction on days when there's been no actual, physical activity to speak of.) The Qi-charging, iOS-pairing Spire is up for pre-order today at a price of $150, but you might find it on a temporary discount if you're quick.