Biosensor monitors GI sounds to predict postoperative ileus

The US Food and Drug Administration gave 510(k) clearance to a disposable biosensor that will help predict which abdominal surgery patients will develop postoperative complications.

The 1-inch, noninvasive, disposable device, which adheres to a patient’s abdomen, is embedded with a microphone to perform acoustic gastrointestinal surveillance (AGIS). The device connects to a computer that measures acoustic intestinal rate (IR), defined as motility events/minute. These data help predict which patients will have postoperative ileus (POI). Patients with POI who are given food too soon after surgery can suffer severe abdominal pain, nausea, vomiting, abdominal distention, and even life-threatening illnesses.

“With the biosensor, we can now record bowel sounds, which we consider a new vital sign that should be monitored along with heart rate, blood pressure, and respiration,” said the primary investigator of the AGIS device Brennan Spiegel, MD, MSHS, Director of Health Services Research at Cedars-Sinai, in Los Angeles, CA.

Up to 25% of patients who have undergone abdominal surgery cannot tolerate feeding afterwards. “If there were an objective marker that could predict—as early as possible—which patients are developing POI vs those who will uneventfully recover GI function, it could help surgeons and nurses expedite feeding in patients ready to eat, yet delay feeding in those likely to experience further complications,” the authors wrote.

To that end, Dr. Spiegel developed the patented digital device with William Kaiser, PhD, Professor of Electrical Engineering at the Henry Samueli School of Engineering and Applied Science at University of California Los Angeles. They and other investigators described their findings in a study published online September 25, 2015 in the Journal of Gastrointestinal Surgery.

In this investigation, researchers applied AGIS to 28 patients for 60 minutes before and after abdominal surgery. Of these patients, 9 developed POI. Median IR was 3.01/minute in the POI group and 4.46/minute in the non-POI group.

From these findings, investigators concluded that AGIS can rule out POI with more than 80% certainty. “This offers added confidence to advance feeding earlier in those for whom it is safe,” they wrote.

For now, the biosensor is being evaluated further in an ongoing clinical trial. But the technology could have applications beyond postoperative ileus. “For example, the device may be helpful to monitor people suffering from pancreatitis, inflammatory bowel disease, and irritable bowel syndrome,” Dr. Spiegel said. “We’re also exploring the potential for using similar biosensors in the management of preterm infants in the neonatal intensive care unit because determining when to feed them is a huge issue.”

Starting in 2016, the biosensor will be marketed as the Abstats® System by GI Logic, a medical device company based in Pasadena, CA.

The investigators did not receive outside support to conduct their study, according to their article in the Journal of Gastrointestinal Surgery.