In the near future, people with minimal hand function will be able to easily manipulate devices such as wheelchairs, computers and smartphones, wearing a smart mouthguard that accurately and quickly interprets complex bite patterns into instructions. to regulate electronic devices.
This controlled-bite optoelectronic platform is the first of its kind and was invented by a research group led by Professor Liu Xiaogang from the University’s Department of Chemistry. national university of singapore (NUS) Faculty of Science, with collaborators from Tsinghua University.
Several assistive technologies such as eye tracking, voice recognition, and brain-computer interfaces have been designed in the past to help people, especially those with neurological disorders or limited dexterity, control electronic gadgets. However, these technologies have limitations related to cost, control accuracy, environmental interference, and maintenance.
To provide a favorable replacement for current assistive technologies, Prof. Liu and his team successfully designed and illustrated a smart mouth guard that includes built-in pressure sensors to recognize occlusal patterns. These models are interpreted into data inputs with 98% accuracy and can be used to regulate smartphones, computers and wheelchairs.
The team’s technological innovation was reported in the October 10e2022, issue of the journal Natural electronics.
In addition to supporting human-computer interaction, the interactive mouth guard can also be used for health devices such as smart electronic skin, medical assistance and dental diagnosis.
Limitations of current assistive technologies
Assistive technologies help to enhance the autonomy and independence of people with disabilities. Unfortunately, these technologies also have major drawbacks. For example, voice recognition requires a large operating memory and must operate in a low noise environment, while eye tracking requires a camera to be placed in front of the user and is susceptible to fatigue.
Although brain-computer interfaces have been greatly improved in recent years, this technology is invasive and requires bulky wired instruments.
Bite force, frequently used as a factor to measure chewing function, is a favorable domain that is not properly understood or exploited. As dental occlusion offers high precision control and requires marginal skills, the NUS team formulated a new idea of assistive technology using proprietary models of occlusal contacts.
Translate bite patterns into useful data for device control
The NUS team first designed a sensor containing a series of contact pads having various colored phosphors – these are materials that produce light in response to pressure. The network of contact pads is positioned inside a flexible mouth guard.
The bite leads to the mechanical deformation of the contact pads, which then produce light of different colors and intensities. This can be quantified and processed using machine learning algorithms. The collected data is then used for high precision remote control and operation of many electronic gadgets, such as wheelchairs, computers and smartphones.
Weighing approximately 7g, the new mouth guard requires minimal training experience compared to current assistive technologies.
Our optoelectronic bite-controlled system is capable of translating complex bite patterns into data inputs with 98% accuracy. We have also demonstrated that our new sensors can distinguish between mechanical deformations, including strain, compression, and bending, making them applicable to multifunctional mechanical sensing applications, such as miniaturized force sensing, flexible electronics, artificial skin and dental diagnosis.
Professor Liu Xiaogang, Department of Chemistry, Faculty of Science, National University of Singapore
Each smart mouthguard currently costs S$100 to create in the lab, and the researchers predict the cost would be dramatically low in mass production. Although the current prototype is designed for well-aligned teeth, a mouthguard with an uneven arrangement of phosphorus-infused pads could be created for users with different tooth patterns or for people who wear dentures.
The researchers have filed a patent for this breakthrough technology and are looking for opportunities to authenticate their device in a medical setting, such as nursing homes or care centers. Simultaneously, the NUS team is also looking for ways to improve its technology, such as faster data processing and training.
Hou, B. et al. (2022) An interactive mouthguard based on mechanoluminescence-powered fiber optic sensors for bite-controlled device operation. Natural electronics. doi.org/10.1038/s41928-022-00841-8.