Les Baugh, who lost both arms in an electrical accident 40 years ago, became the first bilateral shoulder-level amputee to wear and simultaneously control two of modular prosthetic limbs. Baugh was able to operate the system by simply thinking about moving his limbs. (Johns Hopkins University Applied Physics Laboratory)

Not to lay too much prosthetics wizardry on you in one week, but Johns Hopkins University has now released a video of a patient controlling two robotic arms -- and unlike a previous experiment with mind-controlled limbs that we described, the patient can actually wear these on his body.

Les Baugh lost both his arms in an electrical accident 40 years ago. But after decades without the limbs, he's now the first bilateral shoulder-level amputee to wear and control two robotic prosthetics at once.

Baugh is a courageous test subject. Before he could be fitted for the limbs, he had to undergo painful surgery. Doctors reassigned the nerves that had once controlled his arms, moving them so they now controlled muscles in his chest. This allows the prosthetics to sense and interpret the signals of those nerves.  In the video above, Baugh admits that this surgery was more painful than the accident that took his arms in the first place.

But then the fun started: Baugh was fitted with a custom socket (it looks a bit like a vest made of hard plastic) that both supports his new limbs and reads the electrical signals sent out by his nerves. Then he went through the process of teaching his limbs how to obey him. Researchers had Baugh work with a virtual reality version of the arms, having him think through the motions he wanted to complete while they read his nerve activity. This way, the arms know what the signals his body puts out are supposed to mean.

In theory, Baugh has the ability to control both arms with the full range of motion that humans take for granted -- every joint in the hands, shoulder, and elbow moving naturally and fluidly. In practice, it's a bit more complicated.

You can see that Baugh is able to lift and move objects, but he still needs to pause and redirect his attention every time he moves a different joint of the limb, or changes direction.

But the fact that he can control both arms at once -- even haltingly -- is a big deal.

"I think we are just getting started," Michael McLoughlin, head of the program that created the limbs, said in a statement. "It’s like the early days of the Internet. There is just a tremendous amount of potential ahead of us, and we’ve just started down this road. And I think the next five to 10 years are going to bring phenomenal advancement.”

Baugh will eventually get a set of limbs to take home with him so the team can see how he does using them for everyday tasks. He's looking forward to getting back some of the basic utility that most people take for granted.

"Maybe for once I’ll be able to put change in the pop machine and get pop out of it,” he said.