Development of a negative pressure based active lung simulator

Nowadays lung simulators are an important part of respirator testing, diagnostics, therapy, education and training. Those simulators are developed to simulate human lungs and respiration processes. In the case of an active lung simulator the focus is put on the simulation for physiological and pathological breathing patterns. The presented i-Lung versions are hybrids of active and passive lung simulators. They have a thoracic chamber in common, which is made of PMMA (Polymethylmethacrylate) and in which different lung equivalents can be mounted. The expansion of the lung equivalent is performed by application of negative pressure which is controlled via an adjacent controlling unit. Over the course of time the i-lung model - starting with version 0.1, 1.0 and finally the oncoming model 2.0 - was mainly changed in the setup of the breathing pattern generation. The changes of the setup led to a module based setup of the entire model leading to high flexibility of fields of application and facilitating transportation. Furthermore, the new setup of i-lung 2.0 will be cheaper and it will offer a higher mechanical stability with the same reproducibility of the performed measurements as the i-Lung 1.0. In this paper three different solutions for generating negative pressure for the active lung simulator i-Lung are presented. Further development of the i-Lung should help closing the gap to anatomically and physiologically even more realistic lung modeling.