Control of continuous flow artificial heart using estimated flow rate and pressure head

A total artificial heart (TAH) is not connected to the central nervous system, and then the TAH system has to determine an adequate operation by itself. Pressure and flow rate are important indices for the decision, however, embedded pressure and flow sensors tend to cause thrombus formation and their durability is insufficient. To avoid this problem, we studied the flow rate and pressure head estimation with rotational speed and supplied power using an ARX model. In this paper, we discuss about the TAH control system using the estimated value instead of the measured value. We had experiments to identify parameter of estimator and control flow rate using the estimated value instead of the measured value, in in vitro and in vivo. In the identification experiment, we could verify enough accuracy of estimator. In the control experiment, the control system was stable but a biased error between measured and estimated value was found.