Bionic Arm

man flexing right arm with prosthetic arm

In the 1970s television show The Six Million Dollar Man, astronaut Steve Austin received two bionic legs and a bionic arm. He was also given Superman-level vision from a bionic eye and brain interface. Today, you can watch videos of children, veterans and others benefiting from the latest technology surrounding innovative prosthetics, including the bionic arm.

What is a Bionic Arm?

The word bionic was first used by Dr. Jack E. Steele in August 1958 and combines the words biology and electronics. The bionic-arm technology relies on two factors regarding amputations. First, your brain’s motor cortex, the area controlling voluntary movements, continues to send out signals even if certain muscles aren’t available for control. Second, during an amputation, doctors don’t remove all the nerves, so it’s possible to use them to control a bionic arm.

How it Works

In this video, Claudia Mitchell works with doctors to test a bionic arm that allows her to feel sensations. Have you ever wondered how that works?

A bionic arm is effective thanks to the relocation of nerves from the amputation site to muscles and skin in the chest. A harness supports the arm and electrical amplifiers to and from those transplanted nerves. For example, when Mitchell thinks about moving her bionic hand, her chest muscles twitch and generate an electronic signal that moves her arm and hand. At the same time, small robotic sensors and motors sense touch and signal Mitchell’s brain, allowing her to feel the sensation of grasping a ball or touching an object.

Bionic Arm That Gives Wearers a Sense of Ownership

Canadian firefighter Rob Anderson lost an arm and a leg in a helicopter crash. Anderson wasn’t entirely satisfied with his top-of-the-line prosthetics because he felt as if he were wearing a tool. That’s why he joined a study designed to give wearers a sense of connection to bionic limbs.

The surgery and sensory communication were similar to those described above, but also included inputs and outputs to sensors at the elbow. Also, the remaining nerves at the amputation site were rerouted to tendons in the participants’ bicep, chest and tricep. Researchers vibrated the tendons and asked the volunteers to imitate the perceived movements in the missing limb in their remaining arm.

The team built an extensive library that mapped the stimulated tendon to the perceived movement. This led to the development of a neural-machine interface. The patient wearing the bionic arm thinks about moving the limb, the brain sends the signal to the reinnervated muscles that control the prosthesis. A small, powerful motor vibrates the muscle, generating an illusion of kinesthetic sense.

Helping Kids

The nonprofit group Limbitless Solutions plans to fill a gap in prosthetics, which are often too expensive for the parents of young children with missing limbs. The group has already helped dozens of kids receive free bionic arms that react to brain signals sent to their muscles. These colourful, futuristic limbs cost about $1,000 in hardware and have an extreme cool factor allowing these kids to be envied rather than pitied by their peers.

Conclusion

The technology used to create the bionic arm is on the cutting edge of science and medicine. It’s improving the lives of children and adults with missing limbs and stretching the boundaries between reality and science fiction. For families participating in studies or receiving the prosthetics at no charge, the price tag certainly beats the $6 million Steve Austin’s benefactors spent to turn him into a superhero.