Howells ventilator apparatus prototype

Howells ventilator prototype, developed by Thomas H Howells at General Barnet Hospital, London, 1950-1960

During his time at Barnet General Hospital, Dr Thomas H Howells developed a series of prototypes to develop a ventilator to use during general anaesthesia - a medication that puts a patient into a state of controlled unconsciousness. Using positive pressure to deliver air into the lungs either through a face mask or through a tube in a person's throat, Howells' design meant that the volume of air could be easily adjusted. At the time, ventilation machines were being slowly introduced as a tool of the anaesthetist.

Howells wanted to make a ventilator that was cheaper to make, lighter and more portable than other examples on the market. He was inspired by a consultant at Barnet General Hospital, James Rochford, who had designed an electronic ventilator for use in intensive care. Howells' design was a non-electric machine using the pressure of the anaesthetic gas mixture to power the machine. W Watsons & Sons Ltd went on the make the machine and advertised in medical journals and press.