Optical fiber sensing system could revolutionize monitoring of brain injuries

American Chemical SocietyDec 4 2024

Fiber optics are a means of transmitting information at incredibly high speeds; however, the technology can be used for more than just providing a fast internet connection. Researchers reporting in ACS Sensors have developed an optical fiber sensing system that could help medical professionals monitor patients for complications after a traumatic brain injury. The technology tracks six biomarkers simultaneously, continuously and automatically to provide crucial information on brain health in lab tests.

After a traumatic brain injury, such as a concussion, secondary damage can occur from swelling in the brain. Biomarkers found in blood or spinal fluid provide medical professionals with information on brain health; however, many current methods struggle to monitor multiple biomarkers at the same time. So, Yuqian Zhang, Ali Yetisen and colleagues wanted to create an optical fiber system that concurrently monitors six key brain health biomarkers: temperature, pH, and concentrations of dissolved oxygen, glucose, sodium ions and calcium ions. Optical fibers, similar to the larger ones used in underground fiber optic cabling, are ideal for medical applications because of their small size and their ability to interact with light-absorbing biomarkers or tissues in measurable patterns.

The researchers outfitted six optical fibers with fluorescent tips specific to each biomarker. A special multi-wavelength laser was shone through the fibers and used to monitor the analytes. When one target analyte interacted with a fluorescent tip, the change in brightness was recorded by a computer. Then the six fibers, along with an extra fiber to boost the calcium signal's measurement, were incorporated into a 2.5-millimeter-thick catheter to create a cerebrospinal fluid sensing system. Machine-learning-driven algorithms detangled the fluorescence signals from one another, providing an easy readout of each biomarker.

The catheter sensing system successfully detected the six biomarkers in an experiment with animal brains designed to mimic the conditions of the human brain after a traumatic injury. Next, cerebrospinal fluid samples were collected from healthy human participants and spiked with the brain health biomarkers of interest. The sensing system accurately determined pH, temperature and dissolved oxygen level in these samples and identified changes in the concentrations of the ions and glucose. The researchers say this work demonstrates that their optical fiber system can detect when a secondary injury might be imminent and could help monitor complications from these traumatic injuries in patients.

The authors acknowledge funding from the Royal Society, the National Natural Science Foundation of China and the China Scholarship Council.