The German engineer Dr. Holger Hesse, and his partner, Danish anaesthetist, Henning Ruben, invented in 1956, the world's first non-electric, self-inflating resuscitator known as the Ambu bag.
The Ambu bag resuscitator revolutionized possibility of providing artificial respiration. Today the resuscitator is produced by the Ambu company, which still produces a wide range of single-patient and multi-use resuscitators.