Date of Award
2017
Publisher
North Dakota State University
Document Type
Dissertation
Degree Awarded
Doctor of Philosophy (PhD)
Program
Electrical and Computer Engineering
Department
Electrical and Computer Engineering
College
Engineering
Faculty Advisor
Ewert, Daniel L.
Description
Mechanical circulatory support devices (MCSDs) have gained widespread clinical acceptance as an effective heart failure (HF) therapy. The concept of harnessing the kinetic energy (KE) available in the forward aortic flow (AOF) is proposed as a novel control strategy to further increase the cardiac output (CO) provided by MCSDs. A complete mathematical development of the proposed theory and its application to an example MCSDs (two-segment extra-aortic cuff) are presented. To achieve improved device performance and physiologic benefit, the example MCSD timing is regulated to maximize the forward AOF KE and minimize retrograde flow. The proof-of-concept was tested to provide support with and without KE control in a computational HF model over a wide range of HF test conditions. The simulation predicted increased stroke volume (SV) by 20% (9 mL), CO by 23% (0.50 L/min), left ventricle ejection fraction (LVEF) by 23%, and diastolic coronary artery flow (CAF) by 55% (3 mL) in severe HF at a heart rate (HR) of 60 beats per minute (BPM) during counterpulsation (CP) support with KE control. This research also explains how selection of inflation and deflation timing points for extra-aortic two-segmented cuff counterpulsation device (CPD) can affect the hemodynamic of the cardiovascular system (CVS). A comprehensive analysis of compliance profile timings generated through exhaustive search technique and the one selected through steepest descent method is carried out to predict and compare the difference in SV via computer simulation models. The influence of control modes (timing and duration) of deflation and inflation for extra-aortic two-segmented CPD on hemodynamic factors compared to no-assist HF were investigated. Simulation results (P < 0.05) predicted that the two-segmented CPD with late deflation and early inflation mode would be a suitable mode with 80% augmentation in peak diastolic aortic pressure (AOP), reduction in peak systolic pressure up to 15%, increases in CO by 60% and mean CAF by 80%. The proposed KE control concept may improve performance of other MCSDs to further enhance their potential clinical benefits, which warrants further investigation. The next step is to investigate various assist technologies and determine where this concept is best applied.
Recommended Citation
Qureshi, Muhammad Bilal, "Cardiac Output Improvement in Mechanical Circulatory Support Devices" (2017). Electrical and Computer Engineering. 125.
https://digitalcommons.ndsu.edu/elec-comp-eng/125
Rights
NDSU Policy 190.6.2
Rights Link
https://www.ndsu.edu/fileadmin/policy/190.pdf
Author ORCID Identifier
0000-0002-0030-8959
Handle Identifier
https://hdl.handle.net/10365/28793