Three Indian companies have got licences from NASA to manufacture its indigenously developed ventilators for critical COVID-19 patients. The three Indian companies are Alpha Design Technologies Pvt Ltd, Bharat Forge Ltd and Medha Servo Drives Pvt Ltd, the space organisation said in a statement on Friday.

Apart from the Indian firms, 18 other companies, including eight American and three Brazilian, have been selected to manufacture the critical breathing devices.

The National Aeronautics and Space Administration (NASA), which is an independent agency for space research, aeronautics and related programmes in the US, developed the ventilator specifically for coronavirus patients at its Jet Propulsion Laboratory (JLP) in Southern California. The JPL engineers designed the special ventilator -- called VITAL -- in little over a month and received ''Emergency Use Authorization'' from the Food and Drug Administration on April 30.

The VITAL (Ventilator Intervention Technology Accessible Locally) equipment uses one-seventh the parts of a traditional ventilator, relying on parts already available in supply chains, the space organisation said. This high-pressure ventilator offers a simple, affordable option for treating critical patients while freeing up traditional ventilators for those with the most severe COVID-19 symptoms. Its flexible design means it also can be modified for use in field hospitals, the NASA statement read. "The VITAL team is very excited to see their technology licenced," said Leon Alkalai, manager of the JPL Office of Strategic Partnerships. "Our hope is to have this technology reach across the world and provide an additional source of solutions to deal with the on-going COVID-19 crisis," he said.

NASA said VITAL was developed with input from doctors and medical device manufacturers. A prototype of the JPL device was successfully tested by the Human Simulation Lab in the Department of Anesthesiology, Perioperative and Pain Medicine at Mount Sinai on April 23. A modified design, which uses compressed air and can be deployed by a greater range of hospitals, was recently tested at the UCLA Simulation Center in Los Angeles. A high-fidelity lung simulator tested almost 20 different ventilator settings, representing a number of scenarios that could be seen in critically ill patients in an intensive care unit, it said.