and D. H. Singer (Task Force of the European Society of Cardiology and the North American Society of Electrophysiology), "Heart Rate Variability: Standards of Measurement, Physiological Interpretation, and Clinical Use," Circulation 93 (1996): 1043-65. 30 Arpi Minassian, PhD, Mark A. Geyer, PhD, Dewleen G. Baker, MD, Caroline M. Nievergelt, PhD,