Fundamental Study Of An AC Magnetohydrodynamic Blood Pump

Magnetohydrodynamic(MHD) propulsion,as a new technology, can be used to pressurize, transport and propel conductive fluid, such as sea water, blood, liquid metal, and so on. MHD propulsion types are classified into AC MHD propulsion and DC MHD propulsion by supplied magnetic field. Based on AC MHD fundamental principle and physical characteristics of blood (conductivity), a new blood driver--AC MHD blood pump, is proposed. There is no moving part, no regular distorting part in the MHD blood driver. Therefore, it has no mechanical extrusion to blood, and has little negative effect on the biochemistry characteristics of blood, which are important to artificial ventricular assist device. In this paper, a 2-D analytical model of AC MHD blood driving system was built and the numerical simulation of the model was made. Compared with different cases of different pairs of poles and different magnet modes, the optimal case: 4 pairs of poles and magical loop magnet, is chosen. Based on the decided case, the apparatus of AC MHD blood pump is developed, mainly including a rotary magical loop magnet with 4 pairs of poles and design different annular channels. A series of experiments were carried out to investigate the performance of the blood driving system. Measuring the magnetic field in the annular channel and measuring the fluid velocity when the electric conductivity of fluid and the rotary speed of magnet are different. Moreover, the experimental results are compared with the numerical simulation results. In addition, the paper analyzed the rheology characteristic of blood and how the magnetic field affects the rheology and biochemistry characteristic of blood. The electric conductivities of blood and plasma are also measured, which is of great value to the research of AC MHD blood pump.