FINDLAY IMPLANTABLE 2-STAGE CENTRIFUGAL PUMP

The Findlay centrifugal pump is unique in its two-stage pumping mechan isms and in its complementary interrelationship of the stages to each other and to the exit system, and it forms an extremely efficient unit . The first stage is a lift force pump as an inlet. The second and maj or stage is a shear force pump. Twenty-six prototypes, many multiply m odified, have been hand fabricated, and most have had classic pump fun ction analyses. Six pumps have demonstrated minimal hemolysis (3.5-5 h ). At modest rotation speeds, it pumps water up to 10 L/min. Forty-fou r acute studies in normal dogs have been performed with the Findlay pu mp in a ventricular assist system. Blood flows through the pump ranged from 1.2 to 4.5 L/min. The conclusion is that the Findlay pump has th e ability to operate with low blood damage, performs at acceptable rot ational speed with reasonable hydraulic and mechanical efficiency, and is small and implantable.