Dilation rheology as medical diagnostics of human biological liquids

The dilational rheology of liquid–air interfaces is very sensitive to the contents and composition of surface active molecules in the liquid. Therefore, these rheological quantities along with dynamic surface tension could prove suitable parameters for the diagnosis of certain deseases. The cerebrospinal fluid, expired air condensate and umbilical blood of newborns have been investigated for patients suffering from neurosyphilis and for a reference group for comparison. The visco-elasticity is measured by pendent drop analysis tensiometry with transient and harmonic surface area perturbations. It is shown that the dilational visco-elasticity parameters depend significantly on the disease, i.e. can be used as diagnostic tool.