Development and Evaluation of a Cardiac Coherence Index for Sleep Analysis – HeartMath Institute
The Cardiac Coherence Index (CCI), based on heart inter-beat interval spectral entropy, links high CCI to deep sleep, low to wakefulness, and medium to dreaming.
Where Published: Journal of Psychology in Africa, 30:1, 44-52, 2020. DOI: 10.1080/14330237.2019.1689460.
Authors: Patrick Celka, Niclas Granqvist, Herbert Schwabl, et al.
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