This is an Emerson (John Haven Emerson, 1906-1991) iron lung, an improvement on the Drinker design. It seems to have been Memorial’s second adult-sized iron lung; the first one was a Drinker model donated in 1931 shortly after the gift of the baby respirator. The slide-out bed and portals in the side that allowed nurses to attend to patients without removing them from the lung were Emerson innovations.
Iron lungs were expensive—this one would have cost around a thousand dollars, and the earlier Drinker model almost twice that—and still relatively rare in the 1930’s. Note that this one was also funded through public donations. See more at ic-103.pdf.