Medically Monitoring Cameras Could Replace Skin Sensors

Premature babies kept warm in neonatal incubators could soon be medically monitored with cameras rather than with sensors attached to their skin.

A mock set up of the camera system. Courtesy of Marc Delachaux / EPFL.

The camera system was developed by École Polytechnique Fédérale de Lausanne (EPFL), the Swiss Center for Electronics and Microtechnology (CSEM), and University Hospital Zurich (USZ) as part of the Swiss research program Nano-Tera to improve the way babies’ heart rates and breathing are monitored.

"Skin sensors placed on the babies' chests are so sensitive that they generate false alarms up to 90 percent of the time, mainly caused by the babies moving around," said Jean-Claude Fauchère, a doctor at USZ's neonatal clinic. "This is a source of discomfort for the babies, because we have to check on them every time. It's also a significant stress factor for nurses and a poor use of their time — it distracts them from managing real emergencies and can affect quality of care."

The camera system requires no physical contact. The baby's pulse is detected by analyzing its skin color, which changes ever so slightly every time its heart beats. Breathing is monitored by measuring movements of the baby’s thorax and shoulders. Infrared cameras monitor the babies at night.

The camera system could replace skin sensors, which cause false alarms nearly 90 percent of the time. Courtesy of Marc Delachaux / EPFL.

The optical system was designed by CSEM researchers, who chose cameras that are sensitive enough to detect minute changes in skin color. They teamed up with researchers from EPFL to design algorithms used to process the data in real time. CSEM focused on respiration, while EPFL worked on heart-rate.

"We ran an initial study on a group of adults, where we looked at a defined patch of skin on their foreheads," said Sibylle Fallet, a Ph.D. student at EPFL. "With our algorithms we can track this area when the person moves, isolate the skin pixels and use minor changes in their color to determine the pulse.”

The tests showed that the cameras produced practically the same results as conventional sensors.

USZ will soon begin testing the system on premature babies.