Electrical Impedance Tomography Developed to Identify Brain Hemorrhaging in Preterm Babies

A new US grant is helping researchers to develop a device that not only monitors preterm infants’ delicate brains, but also identifies intraventricular bleeding as soon as it begins. The research should also give physicians a more detailed determination and timeline of how and when brain hemorrhages typically occur in babies.

Nearly one-third of premature infants develop bleeding in the brain after birth, a problem linked with serious long-term effects such as cerebral palsy, blindness, and seizures. But some of these severe complications could be prevented if physicians could identify and treat such brain hemorrhaging, also called intraventricular bleeding, when it begins.

To accomplish this, University of Florida (Gainesville, USA) researchers from the colleges of medicine and engineering have received a two-year, USD 694,000 grant from the US National Institute of Neurological Disorders and Stroke (Bethesda, MD, USA) in collaboration with EGI, Inc. (Eugene, OR, USA) to develop the technology.

“When we look at preterm babies with intraventricular hemorrhages, we detect them after the fact, so we really don’t know what is happening in the brain at the time of the hemorrhage,” said Dr. Michael Weiss, a neonatologist and an associate professor of pediatrics in the College of Medicine who has teamed with biomedical engineer Dr. Rosalind Sadleir, from the College of Engineering, on the project. “If we can identify the exact moment when a bleed occurs, we may be able to develop therapies that can help prevent bad outcomes from happening.”

The researchers will utilize a technique known as electrical impedance tomography (EIT). Using this method, they will be able to view three-dimensional (3D) reconstructions of hemorrhaging inside the brain at any given time, noted Dr. Sadleir, who specializes in the use of EIT to detect bleeding inside the body.

To gather data within the brain, small electrodes are placed on the head. For babies, the researchers plan to use eight electrodes, which they will place on an easy-to-apply bandage. “We collect 182 measurements in the head, and from that we make our picture,” Dr. Sadleir said.

While infants are hooked up to the electrodes, their brains will be constantly scanned for signs of hemorrhaging. If bleeding reaches a dangerous level, an alert will sound, similar to other devices used to monitor premature babies in the neonatal intensive care unit.

Brain bleeding is typically detected through regular ultrasound scanning performed about seven to 14 days after a premature baby is born, according to the National Institutes of Health. Most of the time there are no other symptoms that alert doctors to the bleeding. “If we detect bleeding right when it starts, we have a much better chance of mitigating ill effects and also preventing other secondary conditions that happen after a bleed,” Dr. Sadleir said.

EIT is used commercially in lung monitoring, specifically to measure lung activity when patients are placed on ventilators to assist their breathing. Unlike magnetic resonance imaging (MRI) or computed tomography (CT) scans, the images generated through EIT at times look a little blurry because electrical currents do not travel in straight lines, according to Dr. Sadleir. However, the health care team will not study the images in the neonatal intensive care unit (NICU); instead, the readings will translate to a number. This number will be compared with an acceptable baseline. When bleeding is found, the clinicians can then review the image and perform an ultrasound scan to more effectively target the problem.

“We do a lot of general monitoring in the NICU, but we don’t look at a lot of the end organs, such as the brain,” Dr. Weiss said. “We are starting to find out more and more about babies by using brain-specific monitoring. This knowledge may improve outcomes in preterm babies.”

Related Links:
University of Florida
US National Institute of Neurological Disorders and Stroke
EGI