Brain hemorrhage is one of the most common and lethal forms of stroke affecting more than 2 million patients annually worldwide. When the blood clot forms and obstructs the circulation of cerebrospinal fluid (CSF), it can lead to an even deadlier situation (50-80% mortality) known as post-hemorrhagic hydrocephalus. Surgeons typically use drainage devices to rapidly remove blood from the brain and, recently, the combination therapy using external ventricular drainage with blood-thinning drugs has received much attention. However, these types of small molecules are still not recommended for patients due to the elevated risk for neural inflammation and secondary bleeding. To enable rapid blood removal without the risk of secondary bleeding, inflammation, and drainage device obstruction, we developed a self-clearing catheter with magnetic micro actuator that can generate large enough forces to break down obstructive blood clots by applying time-varying magnetic fields.

In a blood-circulating model, our self-clearing catheters demonstrated a > 7x longer functionality than traditional catheters (211 vs. 27 min) and maintained a low pressure for longer periods (239 vs. 79 min). Using a porcine IVH model, the self-clearing catheters showed a greater survival rate than control catheters (86% vs. 0%) over the course of 6 weeks. The treated animals also had significantly smaller ventricle sizes 1 week after implantation compared to the control animals with traditional catheters. Our results suggest that these magnetic microactuator-embedded smart catheters can expedite the removal of blood from the ventricles and potentially improve the outcomes of critical patients suffering from often deadly IVH.