Cardiovascular diseases (CVD) have reached epidemic proportions with serious consequences in terms of human suffering and economic impact. Therefore, there is increasing motivation to develop low-cost and non-invasive methods to monitor, diagnose, and treat CVD. Traditionally, the aorta has been viewed as a resistive conduit with a Windkessel effect or as a resistive wave conduit connected to an active pump, the left ventricle (LV) of the heart. However, these perceptions fail to explain many observed physiological results. Here, we introduce the heart-aorta as a system which accounts for a wave-pumping mechanism that exists inside the aorta. Based on this new look, we present a novel method and index, the Intrinsic Frequency, for analyzing the dynamics of the cardiovascular system. This concept leads us to a deeper understanding of the physiology and can significantly impact the diagnosis of related clinical diseases. Following this approach, we are able to measure LV ejection fraction using a smartphone (iPhone). In addition, our systems approach has provided us a framework to derive a non-dimensional number (wave condition number) that predicts the optimum aortic wave state in mammals.
Bio: Niema Pahlevan is James Boswell postdoctoral scholar at California Institute of Technology (Caltech) and clinical research investigator at Huntington Medical Research Institute (HMRI). Dr. Pahlevan received B.S. in Mechanical Engineering from University of Tehran, M.S. in Mechanical Engineering from California State University, Northridge, and PhD in Bioengineering from Caltech in 2013 under supervision of Professor Mory Gharib. He joined HMRI in 2014 and established a clinical trial to develop a non-invasive and inexpensive method to measure heart's performance under supervision of Dr. Marie Csete and Dr. Robert Kloner. His research is focused on establishing new techniques and devices of translational medicine, in which mathematical and engineering principles are used to develop novel diagnostic and therapeutic approaches for cardiovascular and cerebrovascular diseases.