In Vitro Comparison of Active and Passive Physiological Control Systems for Biventricular Assist Devices.
The low preload and high afterload sensitivities of rotary ventricular assist devices (VADs) may cause ventricular suction events or venous congestion. This is particularly problematic with rotary biventricular support (BiVAD), where the Starling response is diminished in both ventricles. Therefore, VADs may benefit from physiological control systems to prevent adverse events. This study compares active, passive and combined physiological controllers for rotary BiVAD support with constant speed mode. Systemic (SVR) and pulmonary (PVR) vascular resistance changes and exercise were simulated in a mock circulation loop to evaluate the capacity of each controller to prevent suction and congestion and increase exercise capacity. All controllers prevented suction and congestion at high levels of PVR (900 dynes s cm(-5)) and SVR (3000 dynes s cm(-5)), however these events occurred in constant speed mode. The controllers increased preload sensitivity (0.198-0.34 L min(-1) mmHg(-1)) and reduced afterload sensitivity (0.0001-0.008 L min(-1) mmHg(-1)) of the VADs when compared to constant speed mode (0.091 and 0.072 L min(-1) mmHg(-1) respectively). The active controller increased pump speeds (400-800 rpm) and pump flow by 2.8 L min(-1) during exercise, thus increasing exercise capacity. By reducing suction and congestion and by increasing exercise capacity, the control systems presented in this study may help increase quality of life of VAD patients.
School of Engineering, Griffith University, Southport, QLD, Australia. jo.philipp.pauls@gmail.com.|Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia. jo.philipp.pauls@gmail.com.
Jo P
JP
Pauls
Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.|School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, QLD, Australia.
Michael C
MC
Stevens
Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.
Emma
E
Schummy
School of Engineering, Griffith University, Southport, QLD, Australia.|Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.
Geoff
G
Tansley
Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.|School of Medicine, University of Queensland, Brisbane, QLD, Australia.
John F
JF
Fraser
Center for Technology Innovation, Texas Heart Institute, Houston, TX, USA.|BiVACOR Inc., Houston, TX, USA.
Daniel
D
Timms
Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.|School of Medicine, University of Queensland, Brisbane, QLD, Australia.
Shaun D
SD
Gregory
D006353:Heart-Assist Devices; D006801:Humans; D008955:Models, Cardiovascular; D014655:Vascular Resistance
Active control; Passive control; Physiological control; Ventricular assist devices; Ventricular suction prevention