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Identification and Classification of Physiologically Significant Pumping States in an Implantable Rotary Blood Pump
Author(s) -
Karantonis Dean M.,
Lovell Nigel H.,
Ayre Peter J.,
Mason David G.,
Cloherty Shaun L.
Publication year - 2006
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.2006.00283.x
Subject(s) - identification (biology) , biomedical engineering , medicine , biology , botany
In a clinical setting it is necessary to control the speed of rotary blood pumps used as left ventricular assist devices to prevent possible severe complications associated with over‐ or underpumping. The hypothesis is that by using only the noninvasive measure of instantaneous pump impeller speed to assess flow dynamics, it is possible to detect physiologically significant pumping states (without the need for additional implantable sensors). By varying pump speed in an animal model, five such states were identified: regurgitant pump flow, ventricular ejection (VE), nonopening of the aortic valve over the cardiac cycle (ANO), and partial collapse (intermittent and continuous) of the ventricle wall (PVC‐I and PVC‐C). These states are described in detail and a strategy for their noninvasive detection has been developed and validated using ( n = 6) ex vivo porcine experiments. Employing a classification and regression tree, the strategy was able to detect pumping states with a high degree of sensitivity and specificity: state VE—99.2/100.0% (sensitivity/specificity); state ANO—100.0/100.0%; state PVC‐I— 95.7/91.2%; state PVC‐C—69.7/98.7%. With a simplified binary scheme differentiating suction (PVC‐I, PVC‐C) and nonsuction (VE, ANO) states, both such states were detected with 100% sensitivity.