The influences of size reduction of a Total Artificial Heart on fluid dynamics and blood compatibility.

Over 500,000 people in the UK suffer from heart failure, with 14,000 admitted to hospital each year and 10,000 deaths. Worldwide, 26 million have heart failure, with a predicted increase of at least 46 % by 2030. The health expenditure on heart failure in the US alone is $31 billion. For patients with severe end-stage heart failure the only hope of long-term survival is a heart transplant. However, donor hearts are scarce, and not available for all who need them, resulting in fewer than 200 heart transplants/year in the UK. Alternative treatments are urgently needed to keep patients alive until a donor heart can be found. One alternative is a Total Artificial Heart (TAH): a machine to completely replace the native heart. Unfortunately, the only available TAH suffers from a number of issues.
Scandinavian Real Heart AB have developed a TAH with a completely novel pumping concept based on displacement of a piston and valve. It is hypothesized that the use of positive displacement, rather than rotation, has major advantages for physiological compatibility. To enable smaller patients to benefit, the company are scaling down the Realheart TAH; but if the pumping frequency is increased there is the potential to increase fluid stresses on the blood and cause damage. This project then aims to investigate the impact of reducing the size of the TAH on blood damage. Extensive computational fluid dynamics (CFD) will be required along with the use of numerical modelling of haemolysis (damage to the red blood cells) and the creation of a numerical model for thrombosis (blood clotting).
If proven successful as a "bridge-to-transplant", the TAH could be a viable permanent alternative to heart transplant for suitable patients. This project is an outstanding opportunity to help bring the next generation of mechanical heart pumps to the clinic. By assisting Scandinavian Real Heart AB to optimise their TAH for smaller patients, this research will be invaluable in helping the product gain regulatory approval and be adopted into the clinic. In addition the research will contribute to fundamental science related to incompressible fluid mechanics, blood trauma and clotting, and develop new simulation techniques to advance the field of mechanical circulatory support development.
The research will involve the use of computational fluid dynamics to simulate blood flow within the TAH, the development of numerical models for damage to the different blood components and the interactions between them.