Tiny tooth-mounted sensor monitors nutrient intake in real time
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In order to track the nutritional content of the food we eat, US scientists have developed a tooth-mounted sensor which can transmit live data to a smartphone.
While health apps that track what we eat are becoming increasingly popular, these apps usually require the user to enter details about calorie intake and nutrients based on their own estimates. This often results in inaccurate records (often underestimating the amount of sugar and calories in food), and sub-optimal recommendations based on this data.
In order to more accurately track exactly what we put inside our bodies, a team of researchers at Tufts University in Massachusetts has developed a small, wearable sensor which sits inside the mouth, monitoring the wearer’s intake of glucose, salt and alcohol.
Although some wearable devices for this purpose have already been designed, these tend to be bulky or otherwise impractical, requiring mouth guards, wiring or frequent replacement of the sensor as it degrades.
The researchers – based at the School of Engineering at Tufts – were keen to develop a more practical device, and miniaturised their sensors such that they can fit on 2mmx2mm patches, which are then bonded to a tooth, conforming to its bumpy surface.
The sensors are made up of a layer of ‘bioresponsive’ material, which absorbs nutrients from the food or drink, sandwiched between two layers of small square rings made of gold.
Data collected as the wearer eats and drinks are wirelessly transmitted to a phone using an incoming radiofrequency signal, which is wirelessly transmitted back to the device. Different nutrients cause the sensor to absorb and transmit waves at different frequencies and different intensities.
“In theory we can modify the bioresponsive layer in these sensors to target other chemicals, we are really limited only by our creativity,” said Professor Fiorenzo Omenetto, co-author of the study.
“We have extended common [radiofrequency ID] technology to a sensor package that can dynamically read and transmit information on its environment, whether it is affixed to a tooth, to skin, or any other surface.”
According to Omenetto and his colleagues, this technology could enable the detection and recording of a range of nutrients, chemical and physiological states. Such real-time monitoring could be valuable not just for the health of the wearer – allowing an app or doctor to suggest healthier eating patterns – but could also prove useful in medical studies.
Meanwhile, another team of researchers based at the University of California-San Diego have developed a wearable device which monitors electrical activity in the wearer’s stomach, providing “an electrocardiogram but for the gastro-intestinal tract”; this could allow patients to monitor their gastro-intestinal activity outside of a clinical setting.