Smart pacifier aims at noninvasive electrolyte monitoring in NICUs

A smart, bioelectronic pacifier facilitates wireless monitoring of electrolytes in saliva for babies in the neonatal intensive care unit (NICU), eliminating the need for twice-daily blood draws.

Developed by a group of researchers from several institutions in South Korea and the US, the device seamlessly integrates ion-selective sensors, flexible circuits, and microfluidic channels into a commercial pacifier without additional fixtures or structural modifications.

“The flexible microfluidic channel enables continuous and efficient saliva collection from a mouth. By modifying the surface properties of the channels and the structure of the capillary reservoir, we achieve reliable pumping of the viscous medium for quick calibration and measurement,” the researchers said.

When the device’s feasibility was explored with neonates in the NICU setting, the device was able to perform continuous, saliva-based detection of sodium and potassium levels in real time without induced stimulation. The sensors in the system showed good stability and sensitivity, achieving 52 and 57 mV/decade for the sodium and potassium sensor, respectively. [Biosens Bioelectron 2022;doi:10.1016/j.bios.2022.114329]

“We know that premature babies have a better chance of survival if they get a high quality of care in the first month of birth,” said Jong-Hoon Kim, associate professor at the Washington State University School of Engineering and Computer Science and a co-corresponding author of the study, in a statement. “Normally, in a hospital environment, they draw blood from the baby twice a day.”

Despite being the gold standard, a blood draw can be an agonizing experience for the baby, as the area where the blood samples are taken may become tender or sore. Meanwhile, existing salivary-based detection devices are ineffective for real-time, continuous monitoring of electrolytes owing to their “rigidity, bulky form factors, and lack of salivary accumulation,” Kim pointed out.

What’s more is that monitoring critical electrolytes via blood draw provides only two data points, he continued.

What the smart pacifier device offers, Kim said, is a noninvasive real-time monitoring of the electrolyte concentration of babies.

As the next step in their research, Kim and colleagues are already planning to make the components more affordable and recyclable. A broader testing of the smart pacifier to establish its efficacy is also in the works.

The development of the smart pacifier device is said to be part of a broader effort to help make NICU treatment less disruptive for its tiny patients.

“You often see NICU pictures where babies are hooked up to a bunch of wires to check their health conditions such as their heart rate, the respiratory rate, body temperature, and blood pressure,” said Kim. “We want to get rid of those wires.”