Watch: This color-changing mouthguard lets people remotely control computers via bite
This invention could expand assistive options for people with disabilities.
Wireless technology is now so integrated into daily life that it can practically feel like an additional limb.
Many people rarely part with their accessories like wireless headphones and smart speakers because they’re fun, easy to use, and satisfying — after all, there’s nothing like heating up the car from inside the house on a frosty morning.
And for many people living with disabilities, wireless tech can open up whole new realms of possibility. For example, individuals who aren’t able to control computers with their hands can use a range of devices like eye-tracking software, breath-powered devices, and foot-controlled switches that enable them to click and scroll with relative ease.
Now, scientists may be able to offer another option: bite control.
An international team of researchers recently developed a mouthguard that acts like a remote control and sends users’ commands to bluetooth-enabled devices. Their results were published yesterday in Nature Electronics.
“We wanted to develop some assistive technology that is easy to use for people with disabilities,” says Xiaogang Liu, a chemical engineer at the National University of Singapore and co-author of the new paper. For Liu’s lab, bite-control seemed “like a natural solution.”
Here’s the background — Assistive technology is nothing new. Many scholars trace the origins of modern assistive devices back to the invention of the wheelchair in 1655.
Since then, this field has come a long way. Braille helped open up the written world to visually impaired people in 1829, the first hearing aid arrived in 1876, and electronic speech synthesizers debuted as early as 1936.
Thanks to more recent breakthroughs in wireless technology, users can now control their devices remotely.
Most remote-controlled assistive devices rely on cues from keyboards, voice commands, or eye movements. But these interfaces aren’t a one-size-fits-all solution; each has its drawbacks, and may not be compatible with certain types of disability.
Eye tracking, for example, is extremely helpful for some people, but can be fatiguing and tedious for others. Keyboards can be difficult to operate for those with certain types of neurodegenerative conditions. And voice recognition software “depends upon large operating memory, up-to-date hardware, and low-noise operation,” Liu says.
Now, bite pressure operation could offer a relatively easy-to-use alternative to current technologies.
What’s new — Liu and his team crafted a soft mouthguard packed with fiber optic sensors. Conventional pressure sensors capture electricity, so they’re vulnerable to electromagnetic interference. Instead, these sensors turn certain colors in response to specific biting patterns.
Each color indicates pressure in a certain area of the mouth, and its hue corresponds to bite force. This pattern can be easily represented as a wavelength "signature."
After testing the mouthguard, the researchers fed the light signatures generated by fourteen different types of bite (such as left-to-right, right-to-left, front, back, etc.) to a machine-learning algorithm, which translated each signal into a command. Finally, the command was transmitted via bluetooth to a computer.
This system proved easily adaptable for all sorts of devices — in lab tests, users used it to operate a wide range of electronics, including a smartphone and an electric wheelchair, with 98 percent accuracy.
One participant was even able to play “Happy Birthday” on a virtual piano just by moving their teeth.
What’s next — When (and if) mouthguard remote-controls become standard assistive devices, they still won’t be a perfect fit for every person with disabilities. For example, people who experience facial paralysis may not be able to operate the mouthguard.
And as Liu and his co-authors point out, the mouthguard is designed for people with a standard bite. Those with non-standard dentition would need to have the control custom tailored to fit their mouths — a proposition that would be possible, but likely expensive.
This invention could ultimately expand the list of assistive technologies and allow more people to access computers and other devices. For those who can’t (or don’t want to) use eye tracking or voice commands, bite control might be an attractive option.
For their part, the researchers would also like to one day see their mouthguard integrated into the medical system. “We hope that this technology can be used in care centers, rehabilitation hospitals, and nursing homes,” Liu says.