The two cylinders connect to a pipe with a nozzle, into which the patient breathes. My uncle says the spirometer is an exam. The thinner cylinder tests the stability of his breathing, and the fatter cylinder tests the capacity of his lungs. He sucks on the nozzle, and the cylinder displays 50 percent lung capacity. My aunt leaves for work, and she reminds me to heat soup for my uncle this afternoon. Today is Christmas Day…