A medical system includes a probe, an electrooptical measurement unit, and a processor. The probe, which is configured for insertion into a blood vessel of a brain, includes one or more optical fibers configured to guide an optical signal to interact with a brain clot in the blood vessel, and to output the optical signal that interacted with the brain clot. The electrooptical measurement unit is configured to collect and measure the outputted optical signal. The processor is configured to identify a composition of the brain clot by analyzing the measured optical signal from the probe.
