Test lung

thingiverse

Disclaimer: build intended only for educational or simulation purposes. Commercial test lungs, like the dräger one, can be really expensive so we designed a low cost, low complexity one using a latex balloon from an anesthesia or ventilator circuit. Our model is thought to be connected to an quick garden hose connector** but since the anesthesia balloon has standard connection measurements, it can be also attached directly to a ventilator tubing. This model is capable of firing vent inspiration trigger just taking apart both aluminium plates. Also sliding a overwidth wood strip clamp over the plates allows to change the model’s distensibility. Bill of materials: -. Anesthesia circuit balloon, a 3 liter one in our case. -. Aluminium plate, shaped to cover nearly all the balloon length and width, in our case it's mostly a kind of rectangle 13x35cm with the edges on one side cut. We used 0,8mm thick plate but other materials or sizes might be useful as well. -. 3D printed spacer and connector. -. Wood strips. We used Kapla sized ones, but any size wider than the end of the plate will work. -. Nuts and bolts, again any fitting size can be used. -. Silicone tubing, 10 cm length x 10 mm internal diameter. -. Quick hose connector. -. Worm clamp. Building -. Cut (and polish edges) the aluminium plates adjusted to the balloon size. -. Mark and drill the holes in the plates adjusted to 3D printed spacer holes. -. Place balloon between spacer parts and plates and fix it with the nuts you have. -. Drill holes in two same-sized wood strips. Put nuts to attach both strips and clamp the end of the plates AND the balloon end. -. Attach one end of silicone tubing to the quick hose connector and the other to the 3D printed connector, fix it with the worm clamp. -. Insert the connector to the balloon. If there are any leaks you can add sealing tape at the connector end to increase its diameter and fix the issue. ** See https://www.sciencedirect.com/science/article/abs/pii/S1695403310002808 to understand why