Breakup of a liquid bridge as a method of rheological testing of biological fluids

A method for the on-line testing of small volumes of biological fluids is presented. The method is based on the ability of some liquids to form, when stretched, long thinning filaments, liquid bridges. Measuring the filament thinning rate makes it possible to determine the rheological parameters of the fluid. The method was tested on synthetic polymer solutions and biological fluids, such as saliva, bronchial sputum, follicular fluid, and chicken egg albumen and yolk. The results evidence that this technique can be used in various biomechanical applications, in particular, for disease diagnostics and treatment monitoring.