Sensorless Physiological Control of Implantable Rotary Blood Pumps for Heart Failure Patients Using Modern Control Techniques

The most common type of heart disease is left ventricular heart failure (HF). It usually occurs due to excessive load on the left ventricle (LV) as a result of the systemic circulatory insufficiencies and deprivation of oxygen rich blood to the cardiac muscle by narrowed coronary arteries. Sufferers of this 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 and this number is continually decreasing. This may be due to the fact that HF disease has emerged globally as the largest killer in comparison with other diseases. 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) type left ventricular assist device (LVAD). It has been shown that, in some cases where recipients have had such devices implanted, recovery of the cardiac muscle has been possible allowing the LVAD to be explanted (bridge to recovery). In fact, an LVAD with its continuous operation requires a more complex controller to achieve basic physiological requirements. The essential control requirement of an LVAD needs to mimic the way that the heart pumps as much blood to the arterial circulation as it receives from the venous circulation. In this report, we focus particularly IRBPs and aim 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. We apply concepts and ideas from modern control and estimation theory to achieve the goals. The research consists of the following steps. A pump flow is important physiological hemodynamic variable to study the CVS.