Howells ventilator apparatus prototype

Howells ventilator apparatus prototype, made by Watson of Barnet, England, 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.

Howells was assisted in the making of the prototypes by Albert Miles, an instrument technician at the Barnet Hospitals Group. The cost of making the machine was carefully considered so it suited the needs of clinicians but could also be affordable.