Study on output characteristics of a scroll blood pump

We have developed a scroll blood pump that consists of two scroll disks, an oscillating mechanism connected to a motor and a cylindrical membrane seal made of Pellethane or natural rubber. The fluid is pumped by the oscillating movement of a spiral shaped scroll relative to a stationary scroll whose shape is rotated 180 degree with respect to the moving scroll. The diameter of pump housing is 60 mm and its thickness is 20 mm. An oscillating radius can be changed from 3.0 to 4.5 mm. The clearance between the scroll and the base of the opposite scroll disk was changed from 0.1 to 1.2 mm. For the clearance of 0.1 mm with oscillating radius of 4.0 mm, pump discharged 8.44 L/min against the pressure of 500 mmHg at 900 rpm. At 680 rpm with a 0.5 mm clearance, pump discharged 6 L/min against the pressure of 120 mmHg. The maximum energy conversion efficiency was approximately 24%.