The original "Iron lung" prototype was built by a tinsmith and used vacuum cleaner parts: https://jamanetwork.com/journals/JAMA/articlepdf/403323/jama_255_11_0

The original "Iron lung" prototype was built by a tinsmith and used vacuum cleaner parts: https://jamanetwork.com/journals/JAMA/articlepdf/403323/jama_255_11_030.pdf https://jamanetwork.com/journals/JAMA/articlepdf/403323/jama... (or course, it didn't need to be sterile because unlike modern positive pressure ventilators, the air it pumped didn't go inside the patient).