Dialyzer - virtual product development, ASD GmbH

Flow analysis and design of dialyzers
The current development of dialyzers is characterised by experimental methods for analysis, optimisation and innovation, which can not provide detailed analysis of processes inside the dialyzer due to their integral character. Existing simple models describe the processes in the dialyzer only insufficiently.

"The virtual dialyzer"
ASD has developed a numerical model of virtual flow simulation, that can be used for analysis and description of processes within different dialyzer forms.
Numerical grid of a dialyzer	Fundamental is, that two factors are of special importance for the clearance rate of a modern dialyzer: the permeability of the membrane and the flow across it. If flow conditions around the fibers are not favourable, it will not fully participate in the mass exchange, independently of the quality of permeability. Thus, if the flow conditions close to the membrane are not optimal, an increase of the stated overall performance is not possible or only with an unproportional large surface area.

With our numerical dialyzer simulation it is now possible, to describe the local processes differentiated and to analyse them correctly along the entire length of the dialyzer.		DOWNLOAD high resolution MPEG Animated simulation of particle track and velocity [MPEG-File 2,54MB]
The quantities from the global model, such as pressure drop and velocity distribution, are used as boundary values in the local submodel, which simultaneously analyses the diffusive and convective transport and exchange processes in membrane, blood and dialysate sides for the entire dialyzer.


	Flow distribution and mass exchange

Realistic prediction of clearance rates for certain species and of blood damage potential are therefore possible by using the virtual dialyzer. The optimisation of the dialyzer is efficiently performed by parameter and geometry variations. For manufacturers this offers the chance for assessing and optimising existing designs or designing new devices very fast and cost-effectively.

Flow analysis and design of dialyzers