Oral sodium sensor promises to help blood pressure control

Technology News | May 8, 2018

By Rich Pell

Analog Materials & processes Wireless Communications Test and Measurement Sensing / Conditioning Data Acquisition Wearables Medical Electronics Flexible Electronics

A high sodium intake – via salt in foods – is linked to hypertension (high blood pressure) and increased heart problems. If such intake could be monitored unobtrusively and continuously, it would offer a way to potentially improve hypertension management.

To address this, the researchers developed a soft, low-profile, intraoral (within the mouth) sensing system that offers continuous real-time monitoring of sodium intake via Bluetooth wireless connectivity. The stretchable system integrates chip-scale components and microstructured sodium sensors with stretchable interconnects together in an ultrasoft, breathable, microporous membrane.

“We can unobtrusively and wirelessly measure the amount of sodium that people are taking in over time,” says Woon-Hong Yeo, an assistant professor in the Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. “By monitoring sodium in real-time, the device could one day help people who need to restrict sodium intake and learn to change their eating habits and diet.”

To develop the system, the researchers first used computer modeling to optimize its mechanical properties for use in the curved and soft oral cavity, and then built the system using biocompatible and ultrathin components connected using mesh circuitry rather than traditional plastic and metal-based electronics. They also developed a flexible micro-membrane sodium sensor to be integrated with the miniaturized hybrid circuitry.

“The entire sensing and electronics package was conformally integrated onto a soft material that users can tolerate,” says Yeo. “The sensor is comfortable to wear, and data from it can be transmitted to a smartphone or tablet. Eventually the information could go a doctor or other medical professional for remote monitoring.”

The device can monitor sodium intake in real time, and record daily amounts. With a smartphone or tablet app, say the researchers, users could use the device to plan meals based on how much of their daily salt allocation they had already consumed.

The device was tested in three adult study participants who wore the sensor system for up to a week while eating both solid and liquid foods. Next steps, say the researchers, are to further miniaturize the device, and test it with users who have medical conditions to address, including hypertension, obesity, or diabetes.

Another goal is to do away with the small battery that the sensor requires, which must be recharged daily. One option, they say, would be to power the device inductively, which would use a coil that could obtain power wirelessly from a transmitter outside the mouth.

For more, see “Wireless, intraoral hybrid electronics for real-time quantification of sodium intake toward hypertension management.”