Martha Lillard, the final United States resident dependent on an iron lung for survival, died June 26 in Oklahoma at age 78. Diagnosed with polio at five in 1951, she spent 73 years inside the negative-pressure ventilator that mechanically cycled air through her paralyzed respiratory system. The device — a cylindrical chamber sealing the body from the neck down — represented the primary life-support technology for polio-induced paralysis before modern positive-pressure ventilators replaced it. Lillard's longevity exceeded medical expectations by nearly six decades; physicians initially predicted she would not survive past 20.

The CDC vaccination campaign beginning in 1955 eliminated domestic polio transmission by 1979, rendering the iron lung obsolete for new patients. Yet Lillard's case illustrates the engineering durability of 1920s-era respiratory technology: her unit required specialized maintenance that grew increasingly difficult as expertise vanished. Her sister Cindy Mc Vey described desperate searches for technicians capable of repairing the aging machine in recent years.

Long-haul COVID-19 ultimately reduced Lillard's already compromised lung capacity — below 25% pre-pandemic — to the point where she remained in the chamber nearly continuously for her final two years. The iron lung's negative-pressure mechanism differs fundamentally from today's intubation and BiPAP systems, offering a historical case study in non-invasive ventilation architecture. Her survival demonstrates both the robustness of early biomedical engineering and the irreversible knowledge loss when a technology's user base reaches zero.