Prof. Plamen Ch. Ivanov was elected Fellow of the American Physical Society (Division of Biological Physics, 2010 recipient) for pioneering contributions to biological and statistical physics with the following citation [PDF]:

"For his pioneering application of statistical physics and nonlinear dynamics to physiology and biomedicine, and for uncovering fundamental scaling and multifractal properties, self-organized criticality, sleep- and circadian-related phase transitions in physiologic dynamics."