In many places, tongue piercings are the very emblem of the edgy and the hip who hang out at the local tattoo parlor. Soon they might be more than a fashion statement: they’ll give mobility to people confined by paralysis to wheelchairs.
A team at the Georgia Institute of Technology led by Jeonghee Kim and Maysam Ghovanloo, invented a wheelchair control that uses a headset and a barbell tongue piercing. The work appears in this week’s issue of Science Translational Medicine.
Right now people with tetraplegia -- paralysis of all four limbs -- have to control wheelchairs by sipping and puffing air. That system has some big drawbacks: the tubes have to be cleaned and if the patient has a respiratory problem, and many do, it’s less useful.
Other methods of control -– using brain signals, for instance, or eye movements -– have their own problems. Brian wave systems haven’t proven reliable enough yet and tracking eye movements requires a camera in front of the person’s face, which makes it difficult for the user to see where she’s going. Voice recognition won’t work well for many tetraplegics either, because many have weak voices.
The tongue piercing, or Tongue Drive System (TDS), works by changing the magnetic field around the user’s mouth with a tongue flick. The researchers built a headset that surrounded part of the face. The tongue piercing was a simple barbell-shaped magnet. The headset picked up the changes in the magnetic field of the barbell, with sensors just outside the cheeks. They then relayed information to an iPod the user carried. The iPod detected the tongue commands, and sent them to a powered wheelchair.
The technology was first demonstrated as a prototype at a conference last year. That version had a dental retainer that contained some of the sensors and transmitters. The one used in the new study omitted the retainer.
The researchers tested the technology in 23 able-bodied and 11 paralyzed participants. All received custom-made titanium barbell piercings. After just a half an hour of training, all 33 participants were able to use the TDS, and their performance improved over several weeks. They could play video games, dial phone numbers and drive a powered wheelchair through an obstacle course using only their tongues.
The system also works with computers, so users could move a cursor, which obviates the need for fancy eye-tracking equipment.
Promising as the technology is, there is still some work to be done to get it ready for prime time. Ghovanloo has a startup company, Bionic Sciences, which is working with Georgia Tech to make it a commercial reality. He told DNews that he hopes to do that within two years.
Photo: Dr. Maysam Ghovanloo with a participant from the clinical trial. Credit: Courtesay Maysam Ghovanloo, Georgia Institute of Technology