Optical fibres will help peek into the deepest parts of the brain. A doctoral student from FME is involved in the research

To look through an optical fibre thinner than a human hair inside the human brain. This is the ambition of the scientific team, which includes the doctoral student Miroslav Stibůrek from the FME. So far, experts are testing the so-called holographic micro-endoscopy on mice, but in the future, they would like this tissue-friendly and detailed imaging method to be accessible to human patients as well.

Many people are familiar with endoscopic examinations, such as of the oesophagus or intestines, where a catheter equipped with a camera and other instruments is inserted into the body. These examinations are not particularly pleasant. In the future, the use of smaller probes made of optical fibres could make it easier for patients. Experts from the Institute of Scientific Instruments (ISI) of the Czech Academy of Sciences, whose team includes the doctoral student from the Faculty of Mechanical Engineering at BUT and a graduate of FEEC, Miroslav Stibůrek, are working on the development of these fibres. This year, Stibůrek received an internal BUT grant for young scientists, known as KInG, for research on optical fibres for the human brain imaging.

"People mainly associate fibre optics with fast internet. However, we are able to use a single optical fibre, as thin as a human hair, to image structures inside living tissues. This is at submicron resolution, meaning we can see down to the level of cell organelles," Stibůrek explains.

Compared to current methods of brain examination, optical fibres offer a much more detailed view into the tissue's depth, which devices like CT or tomography cannot achieve. "Today it is always a quid pro quo: if we can image tissues at any depth, we lose the ability to see details; the resolution of devices is usually in millimetres. With light microscopic methods, we achieve great resolution but cannot penetrate depth. Holographic micro-endoscopy allows us to reach any depth and achieve a resolution comparable to light microscopy," Stibůrek adds.

In practice, the use of fibre optics could provide relief to patients as it is a minimally invasive method. Scientists are already testing the technology in the laboratory, and the path to patients – as with all new discoveries in medicine – will take some time. They are currently conducting experiments on mice. "A fluorescently labelled mouse is put to sleep by a veterinarian, its fur on the head is shaved in anaesthesia, the skin is cut, and a small hole, a so-called cranial window, is drilled into the skull. Then, we insert the optical fibre into the brain," describes Stibůrek, who dedicated his doctoral studies to the development of holographic micro-endoscopy.

He is part of the team led by Professor Tomáš Čižmár at the Academy of Sciences. This year, he received a half-million grant from BUT for young doctoral students, which will allow him to spend a year researching the process of preparing optical fibre. "Cutting the fibre and inserting it into the brain is not enough for us. We deposit various layers of metals and polymers, with a thicknesses of several units to hundreds of nanometres. I want to focus on this process of preparation in my work this year," Stibůrek explains, believing that in the future, the research could also turn into a startup that could bring this promising technology to the market and thus to hospitals.

"I enjoy the complexity of our research: there is technology and natural sciences, experiments in the laboratory, and data processing. I would be very happy if the use of optical fibres continued to evolve and eventually found application in clinical practice," the young scientist concludes.

(ivu)

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Published	2022-04-26
Link	https://www.vut.cz/en/alumni/f38103/d225453