Kavin Kukunoor
Pronouns: He/Him
Research Mentor(s): William Lynch
Research Mentor School/College/Department: / Medicine
Program:
Authors: Kavin Kukunoor, Michael Atie, Hannah Matich, Alvaro Rojas, Joe Potkay
Session: Session 6: 3:40 pm – 4:30 pm
Poster: 74
Abstract
Intro The MLung is an Artificial Lung that is designed for pediatric patients as an assistive for oxygenation while the native lungs recover or as a bridge to transplant. Constructed with a bundle of polymethylpentene (PMP) fibers enabling gas diffusion into surrounding blood, the MLung features inner and outer gates with slots guiding blood flow along a concentric pathway. We predict that changing the gate size will affect the rated flow, resistance, and clotting of the lungs. Thus, we produced 3 different designs of the MLung with varying sizes of the slots: 3.25, 5, and 7.5 millimeters. Methods Computational fluid dynamics (CFD) was performed on all three designs to evaluate velocity and shear. This, combined with in-vitro testing, was used to determine which design would be used for in-vivo tests. in-vitro testing was performed using bovine blood, conditioned to venous standards before testing. During testing, the blood flow was adjusted to 0.5-2.5 L/min in increments of 0.5 L/min. We compared rated flow (flow when sO2%>95%), resistance, and clotting in all three MLungs. In-vivo testing was performed using an ovine model that was cannulated from jugular vein to femoral vein. Two MLungs with a slot size of 7.5 mm were tested. Pre and post device blood gas samples were taken every 3 hours. Resistance and post device oxygen saturation (sO2%) were monitored for the entirety of the experiment. Results During In vitro testing we observed a rated flow of 1.5 L/min for the 7.5 mm lung, 0.75 L/min for the 5mm, and 0.6 L/min for the 3.25 mm. At 1 L/min of blood flow resistance was 5 mmHg/L*min for the 7.5 mm lung, 8 mmHg/L*min for the 5 mm lung, and 12 mmHg/L*min for the 3.25 mm lung. When tested in vivo, the first lung had an initial sO2% of 95.2% and a final value of 100%. The initial resistance in lung 1 was 0.001 mmHg/mL/min and final resistance was 0.159 mmHg/mL/min. Lung 1 lasted 5 hrs before showing signs of clotting. Lung 2 had an initial sO2% of 100%, and a final value of 86.9%. Initial resistance of lung 2 was 0.037 mmHg/mL/min, and the final value was 0.039 mmHg/mL/min. Lung 2 lasted 19 hrs before removal. Conclusion In vivo testing showed that there is still further optimization needed. Lung 1 clotted after 5 hours, confirmed by a final resistance 159 times greater than initial. Lung 2 was removed after 19 hours and had consistent resistance, though it showed signs of failure at 8.5 hours as its post device sO2% fell below 95%, likely due to clotting as well. In the future we plan to switch to a denser fiber mat and switch to using biocompatible resin for the MLung housing to mitigate clotting.
