Johann Dräger

Johann Heinrich Dräger (1847-1917) was a German entrepreneur, watchmaker and founder of the Drӓgerwerk company.

It would be his first invention (a father-son initiative) the Lubeca valve also known as the “beer pressure regulator” – used to control the carbon dioxide in beer barrels – that would propel him into the vices of medical technology.

Drӓger collaborated with friend and surgeon Dr Otto Roth to develop the Roth-Drӓger anaesthetic apparatus which was the first of its kind to ‘tame’ anaesthesia and allowed the anaesthetist to reliably control oxygen and anaesthetic agents.

Between 1900 and 1928 Heinrich and his son Bernard were granted 261 German and 443 foreign patents and 912 utility models.

Perhaps foremost, he is known as the innovator behind the Pulmotor, the first artificial ventilator in the world. Although its use never entered the hospitals or anaesthesia, it lay the foundation for modern ventilators today. The Drӓger name persists in the nomenclature today and continues to make significant contributions to medical technology through the company he founded.

  • Born on July 29, 1847 in Kirchwerder, Lübeck the son of a servant and watchmaker
  • 1863 – Following the early death of his father, Drӓger completes an apprenticeship as a watchmaker and continues work at his father’s watchmaking shop
  • 1879-1886 Drӓger builds and sells sewing machines, clocks and optical instruments. Gains interest in beer pressure equipment
  • 1888 – Founded the company ‘Drӓger und Gerling’ in Lübeck with business partner Carl Adolf Gerling on December 20, 1888. Business includes minor repairs and sale of equipment and innovations such as beer tap systems which use compressed carbon dioxide
  • Issues with gas flow (and beer flow) lead Drӓger to invent the Lubeca valve with son Bernhard (1870-1928); this was the first reducing valve for carbon dioxide and the Drӓgers’ first patent. He decides to produce and sell these himself
  • 1892-1895 The company grows to become an industrial enterprise; the company is later named “Drӓgerwerk”
  • 1899 – Attention turns to the use of compressed oxygen and its applications in basic technology such as soldering and welding equipment to ventilators and respiratory protective devices. Led by son Bernhard Drӓger, the company begins production of the oxygen/hydrogen machine, a reducing valve for portioning the oxygen and hydrogen and a high-pressure gauge, the Finimeter to mark the ‘fill’ level of oxygen in cylinders
  • 1902 – Develops the Roth-Drӓger anaesthetic apparatus with good friend Dr Otto Roth (1863-1944). For the first time, the mixing of oxygen and anaesthetic agents is able to be reliably controlled; 1500 Roth-Drӓgers are sold globally over the next 10years and establishes the Drӓger company as a pioneer in medical technology. An alkaline cartridge is later produced to address the problem of theatre pollution from anaesthetic gases and a closed circuit is developed. The cartridge binds the exhaled carbon dioxide and ‘purifies’ the air
  • 1904 – Developed the Drӓger Model 1904 as the first reliable long-term breathing apparatus used primarily by mine rescue teams and fire brigades. It has a service life of two and a half hours.
  • 1906The Courrières mine disaster. occurs where an explosion at a French coal mine causes more than 1000 workers to die from fire, poisonous gases and collapsing rubble. The rescue workers are equipped with the Drӓger Model 1904 and is praised as an apparatus that ‘performs miracles’. By 1924 more than 5000 devices are in use internationally and the term ‘Drӓgermen’ is coined by American emergency responders in commendation to the quality of the product. Today it is used as a synonym for a member of a mine rescue team in America and Canada
  • 1907 – the world’s first ventilator is produced – the pulmotor. The motivation for its development arises when Drӓger witnesses a young man pulled from the Thames whom is resuscitated. He resolves to design a machine that would ‘pump oxygen or fresh air into the lung.’ The original concept is published in ‘The development of the Pulmotor.’ Drӓger leaves it to his son Bernhard to develop the design into a commercially marketable product
  • Died on May 29, 1917 in Lübeck

Medical Eponyms

The inventions that follow are primarily credited to his son Bernhard Drӓger and include diving apparatus, high altitude breathing apparatus and gas masks during the outbreak of WW1. Bernhard continued the company after his father’s death and later developed improvements to the original pulmotor. The company survives today through Johan’s great great grandson Stefan.


The first artificial respiration device that could deliver gases to and from the patient at specific volumes. Its use was primarily in mining disasters as well as in the resuscitation of victims of smoke inhalation, drowning and electric shock. It was operated by compressed oxygen in a cylinder and created alternating positive (20cm H2O) and negative airway pressure (-25cm H2O).

Pulmotor Drӓgerwerk 1907
Der Ur-Pulmotor (1907): Versuchsmodell der von Heinrich Dräger zum Patent angemeldeten ersten Version des Pulmotors | Drägerwerk AG & Co. KGaA

Drӓger used the principle of what is now known as time cycled ventilation, that is, ventilation over a constant length of inhalation and exhalation, a technique not unexpected from a skilled watchmaker. While a ground-breaking concept, the proto-pulmotor was flawed in two ways – first was the considerable re-inhalation of exhaled gas and second was the poor adaptability of the breathing pattern to the patient due to the inflexible control of the movement.

Drӓgers son Bernhard fixed these defects by redesigning the valve system controlling the flow of gases and altering the connecting apparatus such that the patients’ inhaled and exhaled air could be separated by alternating the valve control thereby reducing rebreathing of carbon dioxide. The risk of barotrauma arising from the rigid control system of the original pulmotor was addressed by engineer Hans Schroder who developed a control mechanism where inhalation and exhalation could be automatically switched depending on the airway pressures.

Roth-Drӓger apparatus

Important components included the oxygen cylinder, pressure reducer, a drip feed device and the anaesthetic agent. Oxygen pressure and flow was controlled by the pressure reducer; the gas flow would subsequently drive an injector which would draw chloroform from its storage cylinder.

The amount of chloroform could be titrated by the number of drops per minute and evaporated in the oxygen flow, the mixture of which is then inhaled by the patient. Exhaled gases would be vented to the atmosphere via a separate expiratory valve on the mask thus making this a semi-open system.

The design was later changed on suggestion of Prof Georg Krӧnig who added another drip feed device so that a second anaesthetic agent could be used. A second oxygen driven injector and a hand operated switching valve allowed positive and negative pressure ventilation to be delivered to the patient through the mask; if breathing stopped, the anaesthetist could discontinue the anaesthesia and ventilate with oxygen-enriched air. This was later named the Roth-Drager-Krӧnig apparatus after its collaborators.

1910 Roth-Dräger Mixed Anaesthetic Apparatus
Roth-Dräger Mixed Anaesthetic Apparatus, 1910

Heinrich Drӓger Prize

An annual award that honours an individual for outstanding work and projects in the field of intensive care medicine. The recipient also receives a monetary prize of 2500 euros.

Major Publications


There was much criticism levied by clinical users of the Pulmotor in the 1920’s and concerned the effect of ventilation pressures on the heart and lungs. Foremost would be comments from Dr Yandell Henderson, a specialist in respiratory physiology who repeatedly denounced the Pulmotor and similar resuscitators.

And now a particularly evil affair has developed: that of a device that thirty years ago was introduced as a life-saver, but that was shown to be rather a life-loser, and was therefore rejected; yet that now is again being exploited under another name with all the force of high-powered salesmanship and pseudo- science to the inevitable loss of many lives that could be, and should be, saved. The device to which I refer is a breathing machine that at first was called a “pulmotor

The sole supporting argument for such suck and blow devices is a demonstration that, when one of them is attached to a rubber bag, the bag can be alternately inflated and deflated; and-more dramatically-that when an inflated rubber doll is substituted for the bag, the doll can be made to “breathe” realistically. On this basis, the claim is that, if the human lungs were similarly subjected to alternating positive and negative pressures, they would be similarly ventilated. Yet in reality they are not, unless the positive and negative pressures employed are so large as to induce mechanical injury, dangerous degrees of acapnia and failure of the circulation

Henderson Y, Science. 1943



Eponymous terms

Emergency registrar at Sir Charles Gairdner Hospital, Perth

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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