Artificial kidney has porous membrane parallel to flow - giving effective filtration of particles smaller than pore size

摘要

An artificial kidney comprises a membrane filter having pores of diameter 0.01-0.10 mu and arranged parallel to the flow direction of the blood stream. A pressure difference sufficient to cause filtration is applied across the membrane. The membrane may be arranged flat or cylindrical. Its outlet side may be connected to a buffer soln. circuit. It may be prepd. from cellulose acetate. Particles having mol. wts. in the range 40,000-50,000 although they would pass through a filter of the above pore size if it were arranged transversely to the flow direction, are effectively retained by the filter when it lies parallel to the direction of flow. The vortex radius only needs to be 1/10 of the pore size to prevent practically all the particles from passing through the filter.