Sweat gland activity. You don't have to have wet circles under your arms to be sweating more than usual. Sensors on your hand use a tiny electrical current to measure moisture on your skin. A sensor attached to your finger measures how fast and forcefully your heart is pounding-or how dreamily it's thumping. Sensors around your mouth and nose or chest and abdomen guide you into breathing more deeply, slowly, and regularly.
Feedback takes various forms.
A number on a monitor might reflect how warm your fingers are. A tone might fade as you perspire less. Or you might hit the jackpot when you switch into alpha brain waves, with three cherries lining up on a screen. Expect treatment to take about six to 20 sessions. And don't think you can just relax when you go home.