Researchers at the Department of Chemical Engineering are making use of optical fibres to revolutionise neurocritical care.

Fibre optics are a means of transmitting information at incredibly high speeds; however, the technology may soon be used for more than just providing a fast internet connection.

Research led by former Imperial student Yuqian Zhang and supervised by Dr Ali Yetisen, Department of Chemical Engineering, was published in ACS Sensors. Their research uses an optical fibre sensing system that could help surveil complications after a traumatic brain injury.

The technology monitors six biomarkers simultaneously, continuously and automatically to provide crucial information on brain health. 

After a traumatic brain injury, such as a concussion, secondary damage can occur from swelling in the brain. This is why medical professionals closely monitor for secondary injuries — so they can take immediate action and improve patient prognoses.

Biomarkers found in blood or spinal fluid provide information on brain health, however, many current methods struggle to monitor multiple biomarkers simultaneously and continuously.

This AI augmented fiber optic sensing technology will revolutionise neurocritical care by increasing diagnostic precision. Dr Ali Yetisen Senior Lecturer and co-author, Department of Chemical Engineering

On the significance of this path-breaking use of optical fibres, Dr Ali Yetisen stated: "This AI augmented fiber optic sensing technology will revolutionise neurocritical care by increasing diagnostic precision, leading to improved outcomes for patients with traumatic brain injuries."

Optical fibres: the new sensing system  

Optical fibres, such as those used in fibre optic cabling buried underground, have emerged as a promising new sensing system in medical settings due to their small size and light-transmitting ability.

When the fibres interact with light-absorbing biomarkers or tissues, the intensity of light carried through the fibre changes in measurable patterns. Yuqian Zhang and colleagues wanted to combine multiple optical fibres to create a system that concurrently monitors six brain health biomarkers: temperature, pH, and concentrations of dissolved oxygen, glucose, sodium ions and calcium ions.

The researchers outfitted six optical fibres with fluorescent tips specific for each biomarker. A special, multi-wavelength laser was shone through the fibres 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, by incorporating the six fibres, along with an extra fibre to boost the calcium signal’s measurement, 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 that this work demonstrates that their optical fibre system can detect when a secondary injury might be imminent and could help monitor complications from these traumatic injuries in patients. 

Read the full article: Fully Automated and AI-assisted Optical Fibre Sensing System for Multiplexed and Continuous Brain Monitoring

The American Chemical Society (ACS)

The American Chemical Society (ACS) is a non-profit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

Header image: © [alice_photo] / Adobe Stock