Optimal control algorithm for pneumatic ventricular assist devices: its application to automatic control and monitoring of ventricular assist devices.
We developed a control and monitoring unit for pneumatic ventricular assist devices (VADs), which provides optimal fill and empty control and real-time evaluation of pump performance. The flow signal of the inflow cannula is integrated every beat to yield pump filling volume per pump diastole. The ejection signal is triggered when pump filling reaches a preset level. The instantaneous mean flow of each beat (stroke volume/cycle length) is compared with the previous beat, and the threshold level is readjusted to optimize flow. This feedback loop is repeated every beat, and pump filling is immediately adjusted to yield maximum pump flow. Simultaneously the mean flow of every 10 beats is compared with that of the previous 10 beats; then, the ejection time is readjusted to optimize flow. Initial clinical application of this unit supports its effectiveness and reliability.
Arai
H
H
Department of Thoracic and Cardiovascular Surgery, Hokushin General Hospital, Nagoya, Japan.
Fujiyoshi
K
K
Sakamoto
T
T
Suzuki
A
A
Swartz
M T
MT
D000368:Aged; D000465:Algorithms; D003198:Computer Simulation; D006353:Heart-Assist Devices; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000601:surgery; D011312:Pressure; D011673:Pulsatile Flow; D013318:Stroke Volume / Q000502:physiology*; D018658:Ventricular Septal Rupture / Q000601:surgery*