By proving that uremic patients could be successfully treated using artificial kidneys, Kolff sparked a flurry of activity around the world to develop improved and more effective dialyzers. The “Parallel Plate Dialyzer” evolved as the most significant development of this period. And rather than pumping the blood through membranous tubes, it directed the flow of dialysis solution and blood through alternating layers of membranous material. This development began with the first Skegg-Leonards dialyzer in 1948, and reached its technological peak in 1960 with the presentation of the Kiil dialyzer from the Norwegian doctor Fredrik Kiil. These dialyzers were the predecessors of the current plate dialyzers. Kiil dialyzers were in use in some clinics until the end of the 1990s.


Schematic construction of a Kiil dialyzer according to the original English drawings


Scientific discoveries in the transport of substances across membranes accompanied the technological refinement of dialyzers and began to include dialysis-specific research. These efforts made a quantitative description of dialysis possible and allowed the development of dialyzers with clearly defined characteristics.