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100th anniversary of a pioneer in anaesthesia

“Actually, it’s not that hard to solve problems. The hard part is finding the problem – and to recognise that ’Here is a problem’”. These are the words of Henning Ruben, a true innovator, from an interview in 1982. This Sunday July 20, 2014, he would have turned 100 years.


Henning Ruben, professor of anaesthesiology at the University of Copenhagen (1955-1984), was a man of many talents. Initially a trained dentist, Henning Ruben was, at various times, a professional dancer, mental magician, master swordsman and tireless inventor. Henning Ruben is famous for the invention of the Ruben valve, the foot-suction pump and the self-inflating resuscitator.

Anaesthesiology as specialty
Although Dr. Ruben was educated as a dentist in 1933, he decided to study medicine at the University of Copenhagen from where he graduated in 1946. The young Dr. Ruben found the combination of physiology, pharmacology, and physics of great interest. Therefore he decided to focus his career on anaesthesiology. In 1949 he was appointed anaesthesiologist at Finsen Institute, Copenhagen, and in 1955 he became Professor in anaesthesiology at the Copenhagen University Hospital.

A meeting of minds
In 1953, Henning Ruben met Holger Hesse, the founder of Ambu. Holger Hesse was an engineer with a talent for putting ideas into practice. Ruben and Hesse shared a passion for inventiveness and a close collaboration – as well as a deep friendship – developed between them.

The story behind the resuscitation bag
The story behind the resuscitation bag – which is Ruben’s most famous invention – is that Ruben asked his bicycle mechanic to weld together four bicycle wheel spokes and he then manipulated them into an anaesthesia bag. Subsequently, Dr. Ruben inserted foam rubber in place of the spokes. When manual compression of the bag was interrupted, the re-expansion made the bag self-inflating. He then used his earlier invention, the non-rebreathing anaesthesia valve, as an inflating valve, and an air inlet valve was put onto its tail. Now he was able to ventilate a patient without compressed gas.

The Ambu Bag is born
Holger Hesse saw the prototype and liked the idea. And so the self-inflating bag - also called the Ambu Bag - was born. It revolutionised resuscitation almost 60 years ago and is still used every day all over the world. The Ambu Bags of today contain neither bicycle spokes nor rubber foam, however, the principle of self-inflation remains the same.

A tenacious inventor
Dr. Ruben’s ideas, techniques and devices were all characterised by the same principle: simplicity and accuracy. Therefore Dr. Ruben was well respected during his entire career in anaesthesiology. One of the major honours he received was when the American Medical Association in 1964 declared the self-inflating bag among the most significant medical advances in anaesthesia during the past 25 years. Dr. Ruben died at the age of 90 in 2004, leaving his wife, Vera, four children and seven grandchildren.

His tenacity – and a key to his skill as an inventor – can be found in his own words. “The thing is that some people just curse at a problem, while others keep wondering how it can be solved. This may be what separates inventors from other people. Because I think that everyone has a sum of talents, but some people only use their skills a little, while others, like me, squeeze the orange to the last drop.”

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