Fig. 3: Prospects of NB-fiber in subtle physiological diagnosis.

a The schematic diagram illustrates the placement of the fiber sensor on the arm arteries and muscle groups of the upper extremity, along with the detection principle for monitoring muscle and artery contraction and relaxation. b Microscopic physiological activities within the human body are depicted, and the deformation range of various tissues is statistically analyzed. c The triboelectric mechanism employed by NB-fiber for pulse detection is presented. d Pulse waveforms extracted during exercise and at rest are interpreted and displayed. e Various parameters such as Augmentation Index (AIx), ejection time, and pulse waveform frequency are analyzed in different states, including resting, walking, and running. The top panel shows the variation in pulse frequency obtained through Fourier transform analysis. f A Poincaré plot demonstrates the pulse detection of a 30-second duration in a 22-year-old male. g The electrical signal amplitudes corresponding to muscle strength were measured under different motions. h The sensor’s schematic diagram for pulse and respiration monitoring was provided. i Respiratory waveforms in different states were extracted and interpreted.