Made of stainless steel, and still in good working order, this Emerson Respirator, also known as an "iron lung", was used by polio patients whose ability to breath was paralyzed due to this crippling viral disease. This iron lung was donated to the CDC's Global Health Odyssey by the family of polio patient Mr. Barton Hebert of Covington, Louisiana, who'd used the device from the late 1950's until his death in 2003. Iron lungs encase the thoracic cavity externally in an air-tight chamber. The chamber is used to create a negative pressure around the thoracic cavity, thereby, causing air to rush into the lungs to equalize intrapulmonary pressure. J. H. Emerson Co. manufactured this type of life saving respirator in the 1930s, but in the 1950's and '60's, the invention of portable ventilators made iron lungs obsolete. By 1970, J. H. Emerson Co. ceased manufacturing this apparatus, but many still depend on such mechanical ventilation systems on a daily basis.