PREVENTION OF ATRIAL WALL SUCTION IN A CONTINUOUS-FLOW TOTAL ARTIFICIAL HEART BY CONTROLLING RIGHT PUMP FLOW RATE

Abstract

Cardiac ouput of a total artificial heart (TAH) should be determined by physiological demand to prolong and improve the quality of life (QOL) of the patient. Changes in physiological demand require corresponding changes in blood flow rate. In continuous-flow TAHs, a sudden increase in left pump flow rate to meet the demand often causes suction of the left atrial wall into the inflow cannula. This interrupts physiological control of a TAH. In this study, a control algorithm using a type of balance control between the left and right pumps to prevent atrial wall suction was developed and investigated. Using Terumo Capiox centrifugal blood pumps connected to a laptop computer, the left pump was controlled using a physiological control algorithm based on peripheral vascular resistance while the flow rate of the right pump was controlled using a proportional + integral (PI) control algorithm to Compensate for changes in left atrial pressure (LAP) and keep it relatively constant. Results of in vitro tests and in vivo acute tests in mature goats showed that left atrial wall suction can he prevented from occuring using this method. It was also verified that prevention of atrial wall suction and physiological control in a continuous-flow TAH can be performed simultaneously and independently.