Accuracy evaluation of dynamic volume measurements performed by opto-electronic plethysmograph, by using a pulmonary simulator.

Opto-electronic systems (OS) are motion analysis systems, employed in different clinical applications. Optoelectronic plethysmograph (OEP) is a particular OS able to measure pulmonary volumes, starting from marker displacements, placed on the thorax. The aim of this work is to assess the OED's accuracy on volume measurements, by using a volumetric respiratory simulator (RS). The RS is realized in order to simulate the human quiet breathing and an algorithm computes volume variations. Different trials have been carried out, by measuring volume through OEP and comparing with volume computed by algorithm. Results show OEP accuracy on tidal volume measurement does not depend on thorax displacement's magnitude and it ranges from 9% to 20%. Therefore, accuracy of OEP on dynamic volume measurements appears not to be influenced by thorax's movement magnitude.