A novel mechanical lung model of pulmonary diseases to assist with teaching and training.
BACKGROUND
A design concept of low-cost, simple, fully mechanical model of a mechanically ventilated, passively breathing lung is developed. An example model is built to simulate a patient under mechanical ventilation with accurate volumes and compliances, while connected directly to a ventilator.


METHODS
The lung is modelled with multiple units, represented by rubber bellows, with adjustable weights placed on bellows to simulate compartments of different superimposed pressure and compliance, as well as different levels of lung disease, such as Acute Respiratory Distress Syndrome (ARDS). The model was directly connected to a ventilator and the resulting pressure volume curves recorded.


RESULTS
The model effectively captures the fundamental lung dynamics for a variety of conditions, and showed the effects of different ventilator settings. It was particularly effective at showing the impact of Positive End Expiratory Pressure (PEEP) therapy on lung recruitment to improve oxygenation, a particulary difficult dynamic to capture.


CONCLUSIONS
Application of PEEP therapy is difficult to teach and demonstrate clearly. Therefore, the model provide opportunity to train, teach, and aid further understanding of lung mechanics and the treatment of lung diseases in critical care, such as ARDS and asthma. Finally, the model's pure mechanical nature and accurate lung volumes mean that all results are both clearly visible and thus intuitively simple to grasp.
Chase
J Geoffrey
JG
Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand. geoff.chase@canterbury.ac.nz
Yuta
Toshinori
T
Mulligan
Kerry J
KJ
Shaw
Geoffrey M
GM
Horn
Beverley
B
D004501:Education, Medical; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008171:Lung Diseases / Q000503:physiopathology* / Q000628:therapy; D008954:Models, Biological; D011175:Positive-Pressure Respiration; D012121:Respiration, Artificial / Q000379:methods; D013664:Teaching Materials; D012122:Ventilators, Mechanical