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Development of the Modular Extracorporeal Lung Assist System (ModELAS): ECCO2R and Pediatric Applications

May, Alexandra (2020) Development of the Modular Extracorporeal Lung Assist System (ModELAS): ECCO2R and Pediatric Applications. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Acute and chronic respiratory diseases continue to be a leading cause of death in the United States. Mechanical ventilation has been used to treat these patients, however this can further damage the lungs. Patients with acute hypercapnic respiratory failure have benefited from extracorporeal CO2 removal (ECCO2R) in conjunction with non-invasive or lung-protective ventilation. For patients with end-stage lung disease extracorporeal membrane oxygenation has been used as a bridge-to-transplant. Active rehabilitation while on these devices has shown improved outcomes, however is limited by current, cumbersome systems.

We are developing the Modular Extracorporeal Lung Assist System (ModELAS) as a compact, wearable, platform artificial lung. The ModELAS may be configured for adult low-flow ECCO2R, and pediatric or adult full respiratory support through an exchange of the fiber bundle. The platform nature of this technology allows the pediatric application to leverage the larger adult markets and is likely the most feasible pathway to market for a pediatric device.

This dissertation investigates the ECCO2R and pediatric applications of the ModELAS. A mathematical model was used to define the ECCO2R bundle geometry, and benchtop performance was evaluated followed by in vivo testing. The minimum CO2 removal target of 70 mL/min CO2 removal was met at a blood flow rate of ~250 mL/min. Benchtop studies determined a significant relationship between hematocrit and artificial lung CO2 removal. In vivo plasma-free hemoglobin remained below 25 mg/dL and no thrombus formed within the device under normal operation.

The P-ModELAS was evaluated in 6-hr and 7-day animal studies to validate benchtop performance and optimize cannulation and post-surgical recovery strategies, respectively. The P-ModELAS fully saturated blood while generating less than 20 mg/dL plasma-free hemoglobin. From these studies, an RA to PA cannulation via a right thoracotomy and maintaining a post-surgical 25 IU/kg/hr heparin infusion until the chest tube output stabilizes will be used in upcoming 30-day studies.

In vitro methods were developed to evaluate the effect that the ModELAS impeller design modifications have on thrombus formation at the bottom pivot-bearing. Smoother, zirconium pivots did not appear to decrease thrombus formation compared to ceramic pivots. Washout holes did not further improve thrombus formation.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
May, Alexandraalm318@pitt.edualm318
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairFederspiel, William J.
Committee MemberBorovetz, Harvey S.
Committee MemberWagner, William R.
Committee MemberWearden, Peter D.
Date: 29 January 2020
Date Type: Publication
Defense Date: 11 October 2019
Approval Date: 29 January 2020
Submission Date: 24 October 2019
Access Restriction: 1 year -- Restrict access to University of Pittsburgh for a period of 1 year.
Number of Pages: 134
Institution: University of Pittsburgh
Schools and Programs: Swanson School of Engineering > Chemical and Petroleum Engineering
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Artificial Lung; Extracorporeal CO2 Removal; ECCO2R; ECMO
Date Deposited: 29 Jan 2020 15:32
Last Modified: 29 Jan 2021 06:15


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