It's hard to imagine a world where modern medicine doesn't exist. So many of us take for granted that we live in a time where scientists have developed vaccines, technology, and medicines that help fend off damaging illnesses and treat horrible sympoms.

We haven't seen a polio outbreak, for example, since 1952. It's pretty much gone nowadays, thanks to the development of a preventative vaccine in 1955. But back then, polio victims – if they survived – had to deal with the ongoing consequences that came with the disease.

Paul Alexander from Dallas, Texas, contracted the disease back in back in 1952 when he was just five years old. Like most people afflicted with polio, he had trouble breathing. The solution back then would be to put victims inside a large machine known as the iron lung.

The iron lung was one of the most successful inventions of the time, and it allowed thousands of people with respiratory troubles to breathe again. Patients lie down inside it, and with the device tightly enclosed around the neck, an artificial vacuum is created that mechanically fills the lungs with oxygen.

It was children who were more likely to catch polio, and while they received help from the iron lung, most of them stopped using the machine in their adult lives.

Except for Paul. The now 70-year-old has been using his iron lung since 1952, meaning it's been 65 years since he first got into the machine. The machine is not intended for long-term use, and it hasn't even been manufactured since the 1960s.

It turns out that not only were Paul's lungs badly damaged by polio, but he was also left paralyzed from the neck down. He relied heavily on the machine through-out his life, but it doesn't mean he never achieved anything either.

Paul went to university and became a trial lawyer, which he could attend using a wheelchair. But he always took his machine with him in case his breathing problems flared up.

“When I transferred to University of Texas, they were horrified to think that I was going to bring my iron lung down, but I did, and I put it in the dorm, and I lived in the dorm with my iron lung,” Paul revealed to Gizmodo.

“I had a thousand friends before it was over with, who all wanted to find out what’s that guy downstairs with a head sticking out of a machine doing here?”

Now at age 70, Paul spends most of his life inside the iron lung. While there are more modern alternatives, most polio victims claim nothing is as effective for their condition as the old machine.

But this became problematic for Paul in 2015. He started having some mechanical issues with his lung, and being one of only 10 people left in the world who still use the machine means it's tricky (and costly) to maintain due to its difficult-to-get parts.

Paul turned to the internet for help and posted a video to YouTube, asking if anyone could help him fix the contraption. Luckily for him, mechanic Brady Richards offered to help out.

“I looked for years to find someone who knew how to work on iron lungs,” said Paul. “Brady Richards, it’s a miracle that I found him.”

When Brady brought it into his workshop to fix, it was so old that his younger staff were completely baffled by it. But they managed to fix it, and Paul's iron lung is back in top condition.

Right now, Paul's writing a book about his life. How you ask? By using a pen in his mouth.