Technical characterization of dialysis fluid flow of newly developed dialyzers using mass transfer correlation equations.

Dialysis fluid flow and mass transfer rate of newly developed dialyzers were evaluated using mass transfer correlation equations of dialysis fluid-side film coefficient. Aqueous creatinine clearance and overall mass transfer coefficient for APS-15S (Asahi Kasei Kuraray) as a conventional dialyzer, and APS-15SA (Asahi Kasei Kuraray), PES-150Salpha (Nipro), FPX140 (Fresenius), and CS-1.6U (Toray) as newly developed dialyzers were obtained at a blood-side flow rate (QB) of 200 ml/min, dialysis fluid-side flow rates (QD) of 200-800 ml/min and a net filtration rate (QF) of 0 ml/min. Mass transfer correlation equations between Sherwood number (Sh) containing dialysis fluid-side mass transfer film coefficient and Reynolds number (Re) were formed for each dialyzer. The exponents of Re were 0.62 for APS-15S whereas approximately 0.5 for the newly developed dialyzers. The dialysis fluid-side mass transfer film coefficients of the newly developed dialyzers were higher than those of the conventional dialyzer. Based on the mass transfer correlation equations, introduction of short taper, full baffle of dialyzer jacket and further wave-shaped hollow fiber improves the dialysis fluid flow of the newly developed dialyzers.