A medical system includes a probe, an electrooptical measurement unit, a processor and a treatment unit. The probe, which is configured for insertion into a blood vessel of a brain, includes (a) 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, and (b) a channel selected from a group of channels consisting of an irrigation channel and an aspiration channel. 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. The treatment unit is configured to provide treatment, selected from the group of treatments consisting of dissolving the brain clot by irrigation and aspiring the brain clot through the channel.
