Dan Hedges of ENGINEERING.com bumped into Retired US Staff Sergeant Travis Mills. Sgt. Mills is a quadruple amputee who was invited by Lockheed Martin to explain the workings of his prosthetics. His aim is to promote STEM to the next generation looking to invent the next line of prosthetics.
What brings you to the Science and Engineering Festival today?
"Oh actually Lockheed Martin thought that the science, technology, engineering and mathematics that go into my everyday life, because I'm a quadruple amputee from the Afghanistan war, would be a good fit to tell kids and families about what it is that makes me tick, walk and be able to talk."
Tell us about the mechatronics
"So yeah my prosthetic arm is bio-electric. It reads sensors in my arm. I flex a muscle and it opens … flex it [up] slow and it opens, fast and it rotates ... [Flex it] slow down (arm closes as he talks) fast (arm rotates the other direction). So I can do all those motions."
"Then check down my legs, microprocessors in the knees are Bluetooth capable and I walk, and I talk, and I drive, and I get wild!"
"So I'm very thankful for the designs that I saw here today. The technology that goes into everything as well as the alignment issues, you know the geometries and what not, because if not at the right angles I'd be falling on my face every day."
"And going from having nothing on April 14th, my 25th birthday, and waking up in the hospital in Germany for the first time and finding out. 'Hey man, you're a quadruple amputee.' So now I'm very thankful for the advancements they've made in technology and everything that I'm able to do."
What do you think about the festival and the kids here?
"Oh this is great. I mean the kids here they're tomorrow's geniuses. They're the ones that are gonna build the better legs and everything. So I'm really gonna pump them up! Hey man give me that running leg that will make me dunk a basketball again and things like that."
"No, I think it's great to get the kids involved and aware of all these things. They don't just go to a class and connect a couple of wires and a light turns on. Oh yea I made a circuit! This is like: this is what technology does, this is the science behind it, look what you can accomplish and achieve if you go to school for this kind of thing. And it's something you can get inspired and motivated by."
"So I think it's a great thing and it's a huge event. It's like three floors here! This is full of people and it's awesome. And I'm thankful that Lockheed brought me in and to explain this little portion of technology out there."
Can you go into more detail about how the technology works?
"Alright make a fist. Now flex your hand towards the ceiling. So this muscle right here (points to Dan's extensor digitorum). There's a tiny little sensor, see that little circle on there [on the prosthetic]? It's a topical sensor. So put your hand straight, flex it up slow, if you flex it up slow that muscle flexes slow and [the hand] opens. If you flex it up fast it rotates left. It's all about how fast you twitch the muscle. Don't worry about turning your hand at all … Then as long as you hold it is as long as it twists. I can go all day!"
"Now make a fist, drop it to the floor. Now that muscle right here (points to Dan's flexor carpi radialis), down slow (hand closes), down fast (hand rotates right), that's how I twitch."
"So that's how it works, topical sensors. And I'm very thankful every night and I charge it like a car battery… like a cellphone."
How about the legs? The knees are Bluetooth enabled? Is that right?
"They are. That's how they program them with all the right brake pressure and hydraulic pressure. So I don't break my knee like when I walk and you know it doesn't break too fast or too slow down the stairs."
"And you set that all up. There's also a program with a remote set up for driving. So I got a 25 degree angle, I drive with. My buddy drives with a 38 degree angle … At that angle you push the gas, pick it up and it pushes the break."
"Is it illegal in Maryland? Yes, not all over though so don't worry. I'm in Virginia so we're good. But I learned in Maryland ... WHAT!?"
"So they have running mode, and submersible in water some of them, so it's pretty cool. So my buddy takes his kid to the water park on his X3 knee and they have a day of it. And I'm going to be able to do that too. I have a 2.5 year old!"
Well thank you so much for being here and thank you for your service.
"Thank you I appreciate it."