A team of British anaesthetists have come out with low-cost ventilators which can be used to enable vital support during major healthcare emergencies.
The three prototype low-cost ventilators can also come handy at places where resources are limited, such as in developing countries, remote locations or by the military.
Consultant anaesthetist Dr John Dingley from Morriston Hospital, Swansea, said: "Our research has demonstrated that it is possible to make a gas-efficient ventilator costing less than 200 pounds, for use where 2-4 bar oxygen is available, with no pressurised air or electrical requirements.
"Such a device could be mass-produced for crises where there is an overwhelming demand for mechanical ventilation and a limited oxygen supply."
Dingley, who is also a Reader in Anaesthetics at Swansea University, added: "The physiologist J S Haldane developed a delivery system that provided a high flow of oxygen from a modest fresh gas flow.
"Modern equipment has become so sophisticated that we have, in some ways, lost sight of the basic principles that can be adopted in emergency healthcare situations.
"So our aim was to extend Haldane's concept of maximally efficient oxygen delivery to include pneumatic gas-powered ventilator designs.
"The initial design was envisaged as a ventilator for difficult environments, especially military scenarios, where large oxygen cylinders would be impractical, or in short supply, and electrical power would be unavailable.
"This led to two variants that are suited to emergency construction in bulk for mass deployment prior to a respiratory failure pandemic or other major healthcare situation."
All three designs operate on the principle that the energy is taken from approximately 1 l.min-1 compressed oxygen at a supply pressure of 2-4 bar to provide the motive force to ventilate the lungs.
Dingley explained: "After the stored energy has been used to provide motive power in this way, the waste oxygen - which is now at atmospheric pressure - is then re-used to enrich the air being drawn into the ventilator before it is delivered to the lungs.
"In this way, most of the breathable oxygen is obtained from ambient air."
Experts used a mechanical test lung to test the three devices, which helped provide effective ventilation for patients who were unable to breathe unaided.
Dingley further explained: "These devices could be used anywhere that 2-4 bar oxygen is available, such as a converted ward with no piped air or electricity. In extreme circumstances, they could even run on hospital compressed air, using very little air from the hospital's compressor reservoir.
"The concept, although unconventional, also allows an attending staff member to take over manual ventilation of the patient, with air if necessary, if a hospital's pneumatic mechanism or gas supply fails.
"The mechanism could possibly be made as a single-use device and stockpiled for crises where there is an overwhelming demand for mechanical ventilation, such as a pandemic."
He concluded: "Health services are not designed to cope with the most extreme situations and fast, easy solutions can quite literally save lives. We feel that the low oxygen consumption pneumatic ventilators we have designed and tested could provide a low-cost, speedy solution in a crisis. They could also be used for a wide range of applications, such as rural healthcare and armed conflicts."
The details of the devices have been published online by Anaesthesia.