Moon/mars dust can wreak havoc on an astronaut's lungs. The sharp bits of dust can even cause pneumonia when inhaled for an extended period of time. Spirometer therapy that we use for detecting other lung issues on earth, is gravity based; it would not work anywhere with low gravity conditions. My fun solution can fix all that. It has: 1 mouthpiece, 2 main tubes, 1 main tube, connector, 3 different sized washers, Velcro tipped Nerf foam darts (extra).
The washers provide 3 levels of resistance. You will sandwich one of them between the 2 main tubes inside the screw on connector. This will cause you to have 3 different levels of intensity for your lung therapy. When you exhale forcefully into the tube, the dart will fly out at a different speeds depending on the level you chose, if you have any lung issues, and your lung capacity. The slower it is, the worse your lungs are. Astronauts already invented the game of space darts on the ISS. This fun therapy is taking it to the next level.