Arjun Vallabhaneni
Research Mentor: Alvaro Rojas-Peña
Mentor Department: Department of Surgery-Transplantation, Medicine
Author(s): Arjun Vallabhaneni, Louis W Beardell III, Isabella M. Haladijan, Alisha Malik , Vinisha Somaya , Jingrui Liu, Joseph Potkay , Alvaro Rojas-Peña
Session: Session 2 (10:00 AM – 10:50 AM)
Presentation Type: Poster 103
Abstract
Background: An artificial lung is a component of Extracorporeal Membrane Oxygenation (ECMO) that requires precise regulation of blood oxygen and carbon dioxide levels during in vitro testing. Prior conditioning protocols relied on manually deoxygenating large volumes of blood, which was time-consuming and wasteful of blood supply. To address these issues, we developed an Automated Blood Conditioning (ABC) system that allows continuous, closed-loop regulation of blood in our circuit. Methods: A circuit consists of a reservoir, pump, and oxygenator. Prior to actually collecting data with the ABC system, we have to concentrate our diluted blood via a hemofilter to achieve a target level of ~36 for our hematocrit. Our CDI monitors provide real-time blood gas measurements every 6 seconds and are routinely recalibrated with arterial blood gas samples every 15 minutes. A proportional-integrative-derivative (PID) control algorithm dynamically adjusts sweep gas flow to regulate gas exchange taking place in the oxygenator. In vitro testing was used to assess the system and identify any potential errors in the code, resulting in improved control of carbon dioxide and oxygen levels to prevent respiratory acidosis and alkalosis. Results: In vitro testing revealed our sO2 (saturated oxygen) reaches the target venous range (65% ± 5%) in less than 3 minutes. pCO2 (carbon dioxide partial pressure) reaches its target venous range (45 ± 5 mmHg) within three minutes of the system being activated. Venous conditions were maintained in the conditioning circuit with a subject lung (artificial lung) fully oxygenating up to 2 liters/minute of blood for more than 6 hours. Conclusion: Our patent-pending ABC system is one of the newer approaches to automated blood conditioning in ECMO circuits. Future steps will focus on improving the PID loop for pCO2 and eventually integrating the ABC system into full ECMO circuits. This work was supported in part by NIH R01HL166186.
