A system for gathering pulmonary data includes a smartphone and a back cover for the smartphone. The smartphone has a processor, a display, and a pressure sensor. The pressure sensor is operatively coupled to the processor (e.g. electrically coupled) and the display is also operatively coupled to the processor. The back cover attaches to the back of the smartphone and has an interface for accepting a breath from a user and routing the breath through at least one channel such that the breath is fluidly interfaced between the interface for accepting the breath and the pressure sensor. The application gathers samples of the breath to calculate exhalation volume and pressures and, in some examples, generates and displays a spirogram from the data.
