The development of apparatus for intermittent negative pressure respiration. (2) 1919-1976, with special reference to the development and uses of cuirass respirators.

This paper and the one that preceded it1 have traced the development of the design and use of negative pressure ventilators from their origins in the early nineteenth century to the present day. Their maximum use was in the nineteen-forties and the early fifties after which they were quite rapidly replaced in the treatment of acute respiratory disease by intermittent positive pressure ventilators-the turning point being the severe poliomyelitis epidemic in Copenhagen in 1952. Negative pressure ventilators, particularly cuirass ventilators, still have a place in the treatment of chronic respiratory disease.