Microrobot device removes brain haemorrhages due to strokes or aneurysms

WEST LAFAYETTE, Ind. A new treatment for strokes caused by bleeding in the brain that uses a magnetically controlled microrobot-enabled self-clearing catheter has been shown to be 86% effective in animal models, according to a paper published in nature communication

Hyowon “Hugh” Leean associate professor at Purdue University of the Weldon School of Biomedical Engineering, created the magnetically controlled microdevice that removes blood that accumulates in the brain during a stroke. The innovation was tested on pig models of bleeding in collaboration with neurosurgeons dr. Timothy Bentley from Purdu’s College of Veterinary Medicine and dr. Albert Lee by Goodman Campbell Brain and Spine in Carmel, Indiana.

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The full range of motion of a magnetically controlled microdevice invented by Purdue University associate professor Hyowon “Hugh” Lee to remove blood that accumulates in the brain during a stroke. (Video provided by Hyowon “Hugh” Lee)
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The microrobots successfully removed the blood from six of the seven animals in the animal model.

“This innovation is a real advance in the care of strokes, which are notoriously difficult to treat,” said Hugh Lee.

The current gold standard for stroke treatment is a blood thinner called tissue plasminogen activator, which cannot be used in some hemorrhagic strokes.

“Patients with cerebral haemorrhage have a death rate of up to 50%,” Albert Lee said. “Currently, there is no great therapeutic solution for intraventricular hemorrhage. The only other option is blood clot-dissolving drugs that carry unwanted risks.”

Developed with a former graduate student, Qi Yang, Hugh Lee’s innovation can be activated remotely using externally applied magnetic fields.

“No implanted power source or complicated integrated circuit is required,” said Hugh Lee. “If you change the direction of the magnetic field, the microdevice moves like a compass needle with a magnet nearby. They can be part of an implantable shunt system or part of extraventricular drainage systems.”

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A magnetically controlled microdevice invented by Purdue University associate professor Hyowon “Hugh” Lee removes a clot from the brain.
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Hugh Lee unveiled the innovation to the Purdue Research Foundation Office of Technology Commercialization, which has applied for a patent on the intellectual property. The next step to further develop the device is to obtain approval from the US Food and Drug Administration for an initial human study.

Lee’s joint research was funded by grants from the Indiana Clinical and Translational Sciences Institute and the National Institutes of Health.

About Purdue University

Purdu University is a premier public research institution developing practical solutions to today’s toughest challenges. Ranked as one of the 10 Most Innovative Universities in the United States by US News & World Report in each of the past four years, Purdue delivers world-changing research and extraordinary discoveries. Committed to hands-on and online, real-world learning, Purdue offers a transformative education for everyone. Committed to affordability and accessibility, Purdue has frozen tuition and most expenses at 2012-13 levels, enabling more students than ever to graduate debt-free. See how Purdue never stops in the relentless pursuit of the next big leap at https://stories.purdue.edu

About Purdue Research Foundation Office of Technology Commercialization

The Purdue Research Foundation Office of Technology Commercialization operates one of the most comprehensive technology transfer programs among leading research universities in the US. Services provided by this office support Purdue University’s economic development initiatives and benefit from the university’s academic activities by commercializing, licensing and protecting Purdue intellectual property. The office is housed in the Convergence Center for Innovation and Collaboration in the Discovery Park District in Purdue, adjacent to the Purdue campus. In fiscal 2021, the office reported 159 deals closed with 236 technologies signed, 394 disclosures received and 187 US patents granted. The agency is operated by the Purdue Research Foundation, which received the 2019 Innovation and Economic Prosperity Universities Award for Place from the Association of Public and Land-grant Universities. In 2020, IPWatchdog Institute ranked Purdue third nationally in startup creation and in the top 20 for patents. The Purdue Research Foundation is a non-profit private foundation established to further the mission of Purdue University. Contact [email protected] For more information.

Author: Steve Martin, [email protected]

sources: Hyowon “Hugh” Lee, [email protected]

Albert Lee


Application of a Magnetically Activated Self-Cleaning Catheter for Rapid In-Situ Clearance of Blood Clots in the Treatment of Hemorrhagic Stroke

Qi Yang, Ángel Enríquez, Dillon Devathasan, Craig A. Thompson, Dillan Nayee, Ryan Harris, Douglas Satoski, Barnabas Obeng-Gyasi, Albert Lee, R. Timothy Bentley & Hyowon Lee

Maintaining patency of indwelling drainage devices is critical in preventing further complications following intraventricular hemorrhage (IVH) and other chronic disease treatment. Surgeons often use drainage devices to remove blood and cerebrospinal fluid, but these catheters often become clogged with hematoma. Using an implantable magnetic microactuator, we have created a self-cleaning catheter that can generate sufficient forces to break up obstructive blood clots by applying time-varying magnetic fields. In a circulatory model, our self-cleaning catheters showed >7x longer functionality than traditional catheters (211 vs. 27 min) and maintained low pressure for longer periods (239 vs. 79 min). Using a porcine IVH model, the self-cleaning 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 micro-actuator-embedded smart catheters can accelerate the removal of blood from the ventricles and potentially improve outcomes in critically ill patients suffering from often fatal IVH.

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