Fig. 5From: A Portable Triboelectric Nanogenerator for Real-Time Respiration MonitoringThe sliding mode TENG respiration sensor for monitoring different breathing rhythms. a Photograph of the TENG sensor worn on the waist for respiration monitoring. b The correspondence between the output voltage signals and the processes of exhaling and inhaling in one breathing cycle. c, d Time histories of the output voltage signals for two volunteers with different waistlines (72.8 cm for c and 98.6 cm for d) and corresponding results of FFT for different breathing rhythmsBack to article page