Modern ventilators are electronically controlled by a small embedded system to allow exact adaptation of pressure and flow characteristics to an individual patient's needs.

Invasive methods require intubation, which for long-term ventilator dependence will normally be a tracheotomy cannula, as this is much more comfortable and practical for long-term care than is larynx or nasal intubation.As failure may result in death, mechanical ventilation systems are classified as safety-critical systems, and precautions must be taken to ensure that they are highly reliable, including their power supply.

Ventilatory failure is the inability to sustain a sufficient rate of CO2 elimination to maintain a stable pH without mechanical assistance, muscle fatigue, or intolerable dyspnea.

Some systems are also equipped with compressed-gas tanks, air compressors or backup batteries to provide ventilation in case of power failure or defective gas supplies, and methods to operate or call for help if their mechanisms or software fail.

The former used a Sturmey-Archer bicycle hub gear to provide a range of speeds, and the latter an automotive windscreen wiper motor to drive the bellows used to inflate the lungs.

[7] Electric motors were, however, a problem in the operating theatres of that time, as their use caused an explosion hazard in the presence of flammable anaesthetics such as ether and cyclopropane.

Its principle of operation was very simple, an incoming gas flow was used to lift a weighted bellows unit, which fell intermittently under gravity, forcing breathing gases into the patient's lungs.

This was a robust unit and its availability encouraged the introduction of positive pressure ventilation techniques into mainstream European anesthetic practice.

[10] The mask is composed of a poly(methyl methacrylate) (commercially known as Lucite) block, about the size of a pack of cards, with machined channels and a cemented or screwed-in cover plate.

[11][10] The dynamic pressure and turbulent jet flow of gas from inhalation to exhalation allowed the respirator to synchronize with the breathing of the patient.

It was a small, silent and effective electronic ventilator, with the famous SERVO feedback system controlling what had been set and regulating delivery.

These include current availability,[17][18] the challenge of making more and lower cost ventilators, effectiveness,[19] functional design, safety,[20][21] portability,[22] suitability for infants,[23] assignment to treat other illnesses, and operator training.

[25][26] A major worldwide design effort began during the 2019-2020 coronavirus pandemic after a Hackaday project was started,[27][non-primary source needed] in order to respond to expected ventilator shortages causing higher mortality rate among severe patients.

On March 21, 2020, the New England Complex Systems Institute (NECSI) began maintaining a strategic list of open source designs being worked on.

[33][34] The NECSI project considers manufacturing capability, medical safety and need for treating patients in various conditions, speed dealing with legal and political issues, logistics and supply.

[38] Furthermore, fifty-four governments, including many in Europe and Asia, imposed restrictions on medical supply exports in response to the coronavirus pandemic.

In the initial phase of the pandemic, China ramped up its production of ventilators, secured large amounts of donations from private firms, and dramatically increased imports of medical devices worldwide.

Western Europe and the United States, which outrank China in their production capacities, suffered a shortage of supplies due to the sudden and scattered outbreaks throughout the North American and European continents.

Finally, Central Asia, Africa, and Latin America, which depend almost entirely on importing ventilators, suffered severe shortages of supplies.

[40] In 2006, president George W. Bush signed the Pandemic and All-Hazards Preparedness Act, which created the Biomedical Advanced Research and Development Authority (BARDA) within the United States Department of Health and Human Services.

In preparation for a possible epidemic of respiratory disease, the newly created office awarded a $6 million contract to Newport Medical Instruments, a small company in California, to make 40,000 ventilators for under $3,000 apiece.

[45] On April 7, 2020, Prime Minister Justin Trudeau announced that the Canadian Federal Government would be sourcing thousands of 'Made in Canada' ventilators.