Mouth guard device that monitors health markers in development

Mouth guard

Engineers at the University of California, San Diego, are working on a mouth guard that can monitor health markers, such as lactate, cortisol and uric acid, in saliva and transmit the information collected to a mobile device. The technology is at a proof-of-concept stage, but once ready, it could be used to monitor patients continuously without invasive procedures. Alternatively, it could help athletes monitor their performance or measure soldiers’ stress levels.

Researchers focused on uric acid, which is a marker related to diabetes and to gout and which is currently measured by drawing blood.In the study, researchers focused on uric acid, which is a marker related to diabetes and to gout and which is currently measured by drawing blood. The mouth guard has been tested with human saliva but hasn’t been tested in a person’s mouth.

First, researchers collected saliva samples from healthy volunteers and spread them on the sensor, which produced readings in a normal range. Next, they repeated the process but from a patient who suffers from hyperuricemia, a condition characterized by an excess of uric acid in the blood. The sensor detected more than four times as much uric acid in the patient’s saliva than in the healthy volunteers.

The patient also took Allopurinol, which had been prescribed by a physician to treat their condition, and the device was able to detect a drop in the levels of uric acid over four or five days as the medication took effect. Typically, the patient would have needed blood draws to monitor levels and relied instead on symptoms to start and stop his medication.

Mouth guard was created with a screen-printed sensor using silver, Prussian blue ink and uricase, an enzyme that reacts with uric acid. Because saliva is extremely complex and contains many different biomarkers, nanoengineers have set up the chemical equivalent of a two-step authentication system. The first step is a series of chemical keyholes, which ensures that only the smallest biochemicals get inside the sensor. The second step is a layer of uricase trapped in polymers, which reacts selectively with uric acid. The reaction between acid and enzyme generates hydrogen peroxide that is detected by the Prussian blue ink. That information is then transmitted to an electronic board as electrical signals via metallic strips which are part of the sensor.

Mouth guard was created with a screen-printed sensor using silver, Prussian blue ink and uricase, an enzyme that reacts with uric acid.Finally, the petite electronic board uses small chips that sense the output of the sensors, digitizes this output and then wirelessly transmits data to a connected device.

The next step for researchers would be to embed all the electronics inside the mouth guard so that it can actually be worn. Researchers also will have to test the materials used for the sensors and electronics to make sure that they are completely biocompatible. All this will take about a year, though.

The project was led by nanoengineering professor Joseph Wang and electrical engineering professor Patrick Mercier, who have published their findings in the journal Biosensors and Bioelectronics. The two lead the Center for Wearable Sensors at UC San Diego, which has made a series of breakthroughs in the field, including temporary tattoos that monitor glucose, ultra-miniaturized energy-processing chips and pens filled with high-tech inks for Do It Yourself chemical sensors.