One of the most important things to monitor in patients who’ve sustained a severe blow to the head or a serious hemorrhage is pressure in the brain. This can reveal an increase in the brain’s volume, thanks to bleeding, swelling, or other factors, which can compress and damage brain tissue and starve the organ of blood. Increases in pressure have also been implicated in other, less critical neurological problems, such as migraines and repeated concussions. But current methods for monitoring intracranial pressure are highly invasive—a neurosurgeon drills a hole in the skull and inserts a catheter, which carries a risk of infection.
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