Negative pressure ventilator

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"Iron lung" redirects here. For other uses, see Iron lung (disambiguation).
Negative pressure ventilator
Iron lung CDC.jpg
ICD-9-CM 93.99
MeSH D015919


Method and use[edit]




Invention and early use[edit]


In 1670, English scientist John Mayow came up with the idea of external negative pressure ventilation. Mayow built a model consisting of bellows and a bladder to pull in and expel air.[2] The first negative pressure ventilator was described by Scottish physician John Dalziel in 1832. Successful use of similar devices was described a few years later. Early prototypes included a hand-operated bellows-driven "Spirophore" designed by Dr. Woillez of Paris (1876), and an airtight wooden box designed specifically for the treatment of polio by Dr. Stueart of South Africa (1918). Stueart's box was sealed at the waist and shoulders with clay and powered by a motor-driven bellows.[3] The first of these devices to be widely used however was developed by Drinker and Shaw in 1928.[4] The iron lung, often referred to in the early days as the "Drinker respirator", was invented by Philip Drinker (1894–1972) and Louis Agassiz Shaw, Jr., professors of industrial hygiene at the Harvard School of Public Health.[5][6][7][8] The machine was powered by an electric motor with air pumps from two vacuum cleaners. The air pumps changed the pressure inside a rectangular, airtight metal box, pulling air in and out of the lungs.[9]

The first clinical use of the Drinker respirator on a human was on October 12, 1928, at the Boston Children's Hospital.[6][10] The subject was an eight-year-old girl who was nearly dead as a result of respiratory failure due to polio.[8] Her dramatic recovery, within less than a minute of being placed in the chamber, helped popularize the new device.[7]

Boston manufacturer Warren E. Collins began production of the iron lung that year.[11][12] Although it was initially developed for the treatment of victims of coal gas poisoning, it was most famously used in the mid-20th century for the treatment of respiratory failure caused by poliomyelitis.[5]


In 1931, John Haven Emerson (February 5, 1906 – February 4, 1997) introduced and improved upon a less expensive iron lung.[14][15] The Emerson iron lung had a bed that could slide in and out of the cylinder as needed, and the tank had portal windows which allowed attendants to reach in and adjust limbs, sheets, or hot packs.[9] Drinker and Harvard University sued Emerson, claiming he had infringed on patent rights. Emerson defended himself by making the case that such lifesaving devices should be freely available to all.[9] Emerson also demonstrated that every aspect of Drinker's patents had been published or used by others at earlier times. Since an invention must be novel to be patentable, prior publication/use of the invention meant it was not novel and therefore unpatentable. Emerson won the case, and Drinker's patents were declared invalid.


Both respirator[edit]

Main article: Both respirator


The SA Health Department asked Adelaide brothers Edward and Don Both to create an inexpensive "iron lung".[19] Biomedical engineer Edward Both designed and developed a cabinet respirator made of plywood that worked similarly as the Drinker device, with the addition of a bi-valved design which allowed temporary access to the patient’s body.[18] Far cheaper to make (only £100) than the Drinker machine, the Both Respirator also weighed less and could be constructed and transported more quickly.[18][20] Such was the demand for the machines that they were often used by patients within an hour of production.[21]

Visiting London in 1938 during another polio epidemic, Both produced additional respirators there which attracted the attention of William Morris (Lord Nuffield), a British motor manufacturer and philanthropist. Nuffield, intrigued by the design, financed the production of approximately 1700 machines at his car factory in Cowley, and donated them to hospitals throughout all parts of Britain and the British Empire.[21] Soon, the Both-Nuffield respirators were able to be produced by the thousand at about one-thirteenth the cost of the American design.[19] By the early 1950s, there were over 700 Both-Nuffield iron lungs in the United Kingdom, but only 50 Drinker devices.[22]

Modern usage[edit]



Polio vaccination programs have virtually eradicated new cases of poliomyelitis in the United States. Because of this, the development of modern ventilators, and widespread use of tracheal intubation and tracheotomy, the iron lung has mostly disappeared from modern medicine. In 1959, there were 1,200 people using tank respirators in the United States, but by 2004 there were only 39.[9] Positive pressure respirators were first described by Andre Cournand, JAMA 1947. Although not mentioned, it is known that he worked for the US Air Force during World War 2 and was involved in designing oxygen respirators for bomber pilots flying at high altitudes. This work is apparently classified and has never been released. Positive pressure ventilation systems are now more common than negative pressure systems. Positive pressure ventilators work by blowing air into the patient's lungs via intubation through the airway; they were used for the first time in Blegdams Hospital, Copenhagen, Denmark during a polio outbreak in 1952.[24][25] It proved a success and soon superseded the iron lung throughout Europe.

The iron lung now has a marginal place in modern respiratory therapy. Most patients with paralysis of the breathing muscles use modern mechanical ventilators that push air into the airway with positive pressure. These are generally efficacious and have the advantage of not restricting patients' movements or caregivers' ability to examine the patients as significantly as an iron lung does. However, negative pressure ventilation is a truer approximation of normal physiological breathing and results in more normal distribution of air in the lungs. It may also be preferable in certain rare conditions, such as Ondine's curse, in which failure of the medullary respiratory centers at the base of the brain result in patients having no autonomic control of breathing. At least one reported polio patient, Dianne Odell, had a spinal deformity that caused the use of mechanical ventilators to be contraindicated.[26] There are patients who today still use the older machines, often in their homes, despite the occasional difficulty of finding the various replacement parts.[27] Joan Headley of Post-Polio Health International stated to CNN that as of May 28, 2008, there were approximately 30 patients in the USA still using an iron lung.[28] That figure may be inaccurately low; Houston alone had 19 iron lung patients living at home in 2008.[29] Martha Mason of Lattimore, North Carolina died on May 4, 2009, after spending 60 of her 72 years in an iron lung.[30]


Biphasic cuirass ventilation[edit]



  5. ^ a b Sherwood, RJ (1973). "Obituaries: Philip Drinker 1894–1972". The Annals of Occupational Hygiene 16 (1): 93–4. doi:10.1093/annhyg/16.1.93. Retrieved 2011-07-01. 
  6. ^ a b Gorham, J (1979). "A medical triumph: the iron lung". Respiratory Therapy 9 (1): 71–3. PMID 10297356. 
  7. ^ a b "2010-2011 Student Handbook". Cambridge, Massachusetts: The Harvard Education and Research Center for Occupational Safety and Health. 2010. Retrieved 2011-07-02. 
  14. ^ Geddes, LA (2007). "The history of artificial respiration". IEEE Engineering in Medicine and Biology Magazine: the Quarterly Magazine of the Engineering in Medicine & Biology Society 26 (6): 38–41. doi:10.1109/EMB.2007.907081. PMID 18189086. 
  18. ^ a b c Trubuhovich, Ronald V. (2006). "Notable Australian contributions to the management of ventilatory failure of acute poliomyelitis". Critical Care and Resuscitation 8 (4): 383–5. 
  22. ^ Lawrence, Ghislaine (2002-02-23). "The Smith-Clarke Respirator". The Lancet 359 (9307): 716. doi:10.1016/s0140-6736(02)07819-4. PMID 11879908. 
  23. ^
  27. ^ [1]
  28. ^ "Woman dies after life spent in iron lung". May 28, 2008. Retrieved 2011-07-01. [dead link]

Further reading[edit]

  • Margaret Atwood mentions an iron lung in her book Cat's Eye

External links[edit]