Tokyo — One of the key weapons in the battle to save lives amid the COVID-19 pandemic has been ventilators, which take over breathing for patients in acute respiratory distress. The U.S. has confirmed more than 466,000 coronavirus cases so far, but has only between 100,000 and 160,000 of the artificial breathing machines. Ventilator shortages worldwide are just as dire, and there's no easy fix.

Blue-chip firms like GM and vacuum cleaner maker Dyson have been enlisted in the effort to rapidly manufacture ventilators, while enterprising engineers around the world have come up with some remarkable makeshift options.

While "flattening the curve" may help lessen the need for the machines, they are still in incredibly high demand, and in the U.S. and other countries there's a desperate need not only for ventilators, but for the skilled technicians able to operate them.

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Among the firms watching the global pandemic unfold last month was Metran, a small Japanese company based outside Tokyo that dominates the domestic market for neonatal ventilators. The firm also makes veterinary ventilators, and the bosses decided the breathing machines made for cats and dogs offer the most practical alternative to cope with the ventilator crisis.

"They can be used on anything from mice to a horse," Metran founder Kazufuku Nitta told CBS News from his company's headquarters in Saitama prefecture. As the tube inserted down a patient's throat is sterilized between uses, it doesn't matter whether the patient being intubated is a cat, a human or any other mammal, Nitta said.

A veterinary ventilator made by Metran is seen in a promotional photograph provided by the Japanese company. Metran/handout

The idea of using veterinary ventilators on people isn't Metran's alone. Dr. Beth Davidow, president-elect of the Animal College of Veterinary Emergency Critical Care, has organized veterinary schools and animal hospitals across the U.S. to donate their ventilators to coronavirus patients.

Metran's involvement in the business dates back several decades, to when pet surgery was just starting to become common. Nitta saw that vets were procuring but then struggling to figure out how to properly operate the complex human ventilators, with tragic results. So he modified the device, simplifying it for vets who aren't required to undergo respiratory therapy training.

Now, with worldwide demand for ventilators outstripping not just the supply of devices, but also specialists to operate them, Niita said his company "felt ease of use was extremely important, considering the need in emergency wards and field hospitals."

With just three setting options, he says a nurse or doctor can learn to operate one of his machines in just half an hour. Another selling point for veterinary machines is cost: at about $9,000, the units go for only about 10% the price of a human ventilator sold by his company.

Metran has teamed up with a university hospital in Tokyo, which is clinically evaluating the device as the company seeks approval for human use from Japan's Health Ministry. The firm has recently signed an agreement with a U.K. company that will manufacture its pet ventilators under license for use in that country.

Nitta says he's fielded "about 30" inquiries from around the world, including the U.S., where several organizations and private companies have asked for tens of thousands of units even before they're approved by the FDA for use on people.

But even if approved, his small company can't ship that many right now. The ventilators are assembled by hand, and a veterinary device can be built in a few minutes, Nitta said, but there's a bottleneck in their supply chain.

The director of Metran's international division, Matthew Setterfield, says they can't get enough hoses, valves, motors and electronic parts to ramp up production significantly yet. They only have enough supply to build up to a few thousand ventilators per month for the next several months at their small assembly plants in Japan and Vietnam.

With a fully functioning supply chain, however, they could produce 10,000 per month. Metran hopes to see that capacity and also to extend their reach through other licensing deals.