The Capillary Surfactometer (CS) enables investigators to study pulmonary surfactant and what effect inhibitors have on its ability to rapidly adsorb, spread, and reform a monolayer in the dynamic conditions of the respiratory cycle.

Healthy surfactant prevents alveoli collapse at expiration and that narrow conducting airways maintain patency at all times. Several factors affect surfactant function, inhibiting its ability to function properly causing airways to become blocked. If many airways are affected by inhibited surfactant, airway resistance will be increased and that will lead to a lowering of FEV1. It is likely that this mechanism is part of the reason for the breathing problems affecting patients with asthma, RDS, ARDS, COPD, pneumonia and cystic fibrosis. Animal studies have shown that an exposure to ozone or an infection with respiratory syncytial virus (RSV) will lead to a breathing difficulty and a surfactant dysfunction.

It is also known that ventilation causes further lung damage in some patients. Again, this may be a result of increasingly damaged surfactant.

There are many different types of studies for which the CS can be used, including:

Evaluation of Surfactant preparations

The CS yields immediate information on the effectiveness of specific pulmonary surfactant preparations. The efficacy of new formulations can quickly be verified and they can be compared with other surfactant preparations. Also, the CS can be used to verify batch consistency and quality.

Evaluation of biological lung fluids

Concentrated BAL fluid, diluted tracheal aspirate or possibly sputum can be studied to detect surfactant dysfunction due to phospholipid hydrolysis or to inhibition, most likely from proteins.