Real time heart rate variability assessment from Android smartphone camera photoplethysmography: Postural and device influences
Biofeedback of heart rate variability and related physiology: a critical review.
A pilot study of the efficacy of heart rate variability (HRV) biofeedback in patients with fibromyalgia.
iPhysioMeter: a new approach for measuring heart rate and normalized pulse volume using only a smartphone.
Resonant frequency biofeedback training to increase cardiac variability: rationale and manual for training.
Use of Fourier Series Analysis for Motion Artifact Reduction and Data Compression of Photoplethysmographic Signals