Medical Devices

Viscous Impeller Pump for Fontan patients

Current palliative surgical procedures for single ventricle defects restore near-normal oxygen saturation after Fontan completion at the expense of elevated systemic venous pressure and reduced cardiac output. The Fontan circular is inherently inefficient and known to eventually fail due to the lack of a subpulmonary power source. This so-called "Fontan paradox" could be reversed by adding a cavopulmonary assist device that is capable of creating a subpulmonary pressure rise of 5-7 mmHg. The viscous impeller pump (VIP) proposed by Dr. Mark Rodefeld at Indiana University (https://www.fontanbloodpump.com/) is a long-term mechanical circulatory support system for Fontan patients. The non-obstruction safety feature is critical in the event of pump failure as a modest 2 mmHg pressure loss in the Fontan pathway is clinically significant. In collaboration with Dr. Rodefeld, we are optimizing the hemodynamic performance at 0 RPM using simulation-based optimization techniques to enhance the passive safety of VIPs.

Lab members involved in the project: Weiguang Yang

Bio-printed Pulsatile Fontan Conduit

With the rapid development of bio-printed technology, we are exploring the possibility of placing a bio-printed pulsatile conduit in the Fontan patients to reverse the Fontan paradox. The conduit is designed and will be printed in Professor Mark Skylar-Scott's lab at Stanford University using freeform reversible embedding of suspended hydrogels (FRESH) and sacrificial writing of functional tissues (SWIFT) technologies. We construct a reduced-order model and a multiphysics multiscale computational framework combining electrophysiology, cardiac mechanics, and fluid mechanics to evaluate the performance and optimize the design of conduit prior to printing. With the ideal printed myocytes, this proposed prototype helps to lower 5 mmHg central venous pressure, which is clinically significant and proves the functionality of the pulsatile Fontan conduit.

Lab members involved in the project: Zinan Hu

Coronary Artery Bypass Graft

We are trying to understand vein graft failure in coronary bypass surgeries using computational and experimental techniques. Our goal is to use these insights to develop therapies to prevent vein graft failure. For example, using growth and remodeling computational models we numerically showed that veins can negotiate arterial loads better if the change in loads is gradual, rather than step (as practiced in the clinic today). This idea has inspired a biodegradable external support, to induce a gradual change in load. We have demonstrated its efficacy in preclinical animal models and aim to translate it into the clinic.

Lab members involved in the project: Karthik Menon