Nerve Surgery Leaves Woman With Feeling in an Arm That Isn't There

Sept. 8, 2008— -- Claudia Mitchell may look like your average 20-something college student. She is anything but.

As a result of an experimental surgery, Mitchell has become the first real "Bionic Woman": part human, part computer.

Mitchell's bionic life began in 2004 with a ride on a friend's motorcycle. The bike suddenly spun out of control, and Mitchell's left arm was severed by a highway divider. After her doctor's attempts to reattach the arm proved unsuccessful, she was outfitted with a standard prosthetic arm.

Mitchell thought that her new prosthesis would make her life return to normal. But it didn't work. Her amputation was almost at her shoulder, which made the prosthetic arm all but impossible for her to control.

"It just sat on the shelf. It didn't do anything," Mitchell said.

She grew depressed, thinking she would have to spend the rest of her life with one arm, unable to perform even the most basic tasks. What saved her was a tiny article about an experimental nerve surgery.

The "targeted reinnervation" surgery was developed by Dr. Todd Kuiken of the Rehabilitation Institute of Chicago. It was a radical idea: a robotic arm controlled not by a patient's stump or shoulder, but by a patient's thoughts.

Mitchell, a U.S. Marine, was ready to try anything to have a second functioning arm. She volunteered for the surgery.

During the six-hour procedure in 2006, doctors took the severed and dormant nerves in Mitchell's shoulder, nerves that are used to control the movement of her arm, and put them under the muscle in her chest.

They wanted the nerves to reawaken and work her chest muscle. The doctors eventually used the electrical nerve signals from that chest muscle to power a new bionic arm.

Now, when Mitchell wants to move her arm, she thinks "move." The signal travels from her brain to the muscle in her chest. According to Kuiken, Mitchell's chest muscle then contracts and "lets tiny bits of electricity out."

There are tiny antennas built into the robotic arm, which pick up these electrical signals. The signals then go to an internal computer that decodes them and tells the artificial arm what to do. It's almost instantaneous.

"We have rewired her," Kuiken said.

For Mitchell, living with her new arm has meant constant discovery.

"I have what I call my 'eureka moments,'" Mitchell said. "My stunned 'I can't believe I just did that' moments."

Now she can do the simple things that most people take for granted, like folding a shirt, slicing vegetables or even opening a wine bottle.

"There are a lot of daily tasks that people don't even think about being able to do that I can [do] now," she said.