Medical device maker Medtronic is ramping up efforts to double its output of mechanical ventilators as demand for the lifesaving devices peaks in response to the global outbreak of novel coronavirus.

Ventilators are a critical tool needed to treat patients with severe respiratory problems from the COVID-19 corona_virus, including severe pneumonia. The device takes the workload off sick patients' lungs by supplying oxygen to the body and simulating breathing, allowing their lungs to rest and recover.

The World Health Organization says that 5% of people who become infected with the virus will require treatment in a hospital intensive care unit, and most critically ill patients will need mechanical ventilation.

The U.S. has about 160,000 ventilators ready for use today. Hospitals in the Twin Cities have about 450.

Ventilators have become a flashpoint in the national debate over COVID preparedness.

Sen. Bob Menendez, D-N.J., sent med-tech company CEOs a letter on Wednesday demanding information on the steps they have taken to increase their production of ventilators. Medtronic and Smiths Medical, both of which have their operational headquarters in Minnesota, received the letter.

"Working in partnership, the federal government and industry leaders like your company will need to develop a strategy to meet the anticipated demand for ventilators so that patients will have the necessary life-saving care needed [to] confront COVID-19," Menendez's letter says.

On Thursday, Medtronic officials said the company has already increased its production of the devices by 40% since the start of 2020, bringing its weekly production to several hundred devices per week.

Medtronic's ventilator manufacturing line in Ireland has more than 250 employees, and the company plans to double that number or more, including staff members transferred from other Medtronic sites, spokesman John Jordan said in an e-mail to the Star Tribune.

"Additional manufacturing shifts have been put in place and new manufacturing shift patterns are being introduced to bring the plant to 24/7 operation," Jordan wrote. "With a strong commitment across Medtronic and our suppliers — combined with the increased staffing — the company expects to be able to more than double its manufacturing capacity for ventilators."

Asked how the highly sought-after devices are being distributed, Jordan wrote, "We are prioritizing high-risk, high-need areas for ventilator allocation on a weekly basis for distribution through our supply chain."

Smiths Medical declined to comment Friday morning.