  Sufferers of heart failure disease have a life expectancy of one year and
heart transplantation is usually the only guarantee of survival beyond this
period. The number of donor hearts available currently is less than 3,000 per
annum worldwide. Apart from the relatively fortunate people who receive donor
hearts for transplant, the only alternative for people with HF is the
implantation of rotary blood pump (IRBP). In fact, an IRBP with its continuous
operation requires a more complex controller to achieve basic physiological
requirements. The essential control requirement of an IRBP needs to mimic the
way that the heart pumps as much blood to the arterial circulation as it
receives from the venous circulation. This research aims to design, develop and
implement novel control strategies combining sensorless and non-invasive data
measurements to provide an adaptive and fairly robust preload sensitive
controller for IRBPs subjected to varying patient conditions, model
uncertainties and external disturbances. A sensorless pulastile flow estimator
was developed using collected data from animal experiments. Based on this
estimator, advanced physiological control algorithms for regulation of an IRBP
were developed to automatically adjust the pump speed to cater for changes in
the metabolic demand.The performance of the developed control algorithms are
assessed using a lumped parameter model of the CVS that was previously
developed using actual data from healthy pigs over a wide range of operating
conditions. Immediate responses of the controllers to short-term circulatory
changes as well as adaptive characteristics of the controllers in response to
long-term changes are examined in a parameter-optimised model of CVS - IRBP
interactions. Simulation results prove that the proposed controllers are fairly
robust against model uncertainties, parameter variations and external
disturbances.
