Hyowon “Hugh” Lee, a Purdue University associate professor of biomedical engineering, has created a magnetically controlled medical device to remove blood accumulating in the brain during a stroke. (Image: Purdue University photo/Vincent Walter)

A magnetically controlled micro-robot-enabled self-clearing catheter could be the next big thing in treating strokes, as it has been shown to be 86 percent effective in animals, according to new research.

Hyowon “Hugh” Lee, a Purdue University Associate Professor from the Weldon School of Biomedical Engineering, created the device that removes blood accumulating in the brain during a stroke.

It was tested on porcine models of hemorrhage in collaboration with neurosurgeons Dr. Timothy Bentley from Purdue’s College of Veterinary Medicine and Dr. Albert Lee from Goodman Campbell Brain and Spine in Carmel, Indiana. The microrobots successfully removed the blood in six of the seven animals.

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

The current method for treating strokes is a blood thinner called tissue plasminogen activator, which can’t be used for certain hemorrhagic strokes.

“Patients with brain hemorrhages have a mortality rate of up to 50 percent,” Albert Lee said. “Currently there is no great therapeutic solution for intraventricular hemorrhage. The only other option is blood-clot-dissolving drugs that have undesirable risks.”

Lee’s device can be remotely activated using externally applied magnetic fields.

The full range of motion of a magnetically controlled microdevice that removes blood accumulating in the brain during a stroke. (GIF: Hyowon “Hugh” Lee)

“There is no need for an implanted power source or complicated integrated circuit,” Hugh Lee said. “As 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 a part of extraventricular drainage systems.”

The Purdue Research Foundation Office of Technology Commercialization has filed for a patent on the intellectual property. The next step is to receive approval from the U.S. Food and Drug Administration for a first-in-human study. The research was funded by grants from the Indiana Clinical and Translational Sciences Institute and the National Institutes of Health.

Q&A with Hyowon “Hugh” Lee, a Purdue University Associate Professor from the Weldon School of Biomedical Engineering:

Tech Briefs: Do you plan to seek approval from the FDA for a first-in-human study?

Hugh Lee: We are exploring options to start a company around this technology. We are also looking into licensing the technology to potential partners. Either way, we are committed to translating this work for actual clinical utility.

Tech Briefs: When will this technology be available for use? (How long after the human study?)

Lee: Once we can demonstrate safety and efficacy in human clinical trials, which is a big hurdle by itself, it can take a year or so to get the final FDA approval depending on the regulatory pathways.

Tech Briefs: Will there be a large market for it? Do you think it will catch on?

Lee: According to the American Stroke Association, stroke is the #5 cause of death and the leading cause of disability in the US. The annual economic impact of stroke, just in the US is more than $100 billion (including indirect costs). Out of more than 800,000 annual stroke patients, 13 percent suffer the hemorrhagic type in which bleeding occurs in the brain. According to most studies, the lifetime care cost of hemorrhagic stroke is more than that of ischemic type. So the economic impact of hemorrhagic stroke is still enormous and there is a big demand for improved treatment for hemorrhagic stroke to increase the survival rate and to minimize long-term neurological/disability issues.

A magnetically controlled microdevice invented by Purdue University associate professor Hyowon “Hugh” Lee removes a clot from the brain. (GIF: Purdue University photo/Vincent Walter)

Tech Briefs: How will this change the stroke-treating game? How much will the survival rate increase? Pros? Cons?

Lee: Right now, there is not too many options for hemorrhagic stroke patients. If we can demonstrate in humans that this type of approach is safe and efficacious, I believe it could be a game changer for how we treat these patients. Instead of waiting or considering pharmacological agents to breakdown blood clot, they can immediately be treated without worrying about the drainage device requiring constant replacement or irrigation to accelerate the removal of blood from the brain. We believe this can then increase the survival rate and minimize the long-term effects of hemorrhagic stroke.

Tech Briefs: What are some of the key advantages of this approach?

Lee: The benefit of using our self-clearing catheter is that there is no need for clot-busting drugs, which has been reported to have some serious side effects. Also, these types of drugs can only be given once the bleeding has stopped, which can delay the treatment and cause more extensive neurological damage. We also believe we can use our device immediately in an emergency setting, which can accelerate the treatment timing.

The potential downside of this approach is that it will require an external magnet to be placed over the head of the patient temporarily. However, these patients will likely be incapacitated in ICU for some time and according to our clinical colleagues, this should not be too burdensome.

Tech Briefs: Are you or the team working on any other such advances?

Lee: We are also working on new treatment methods for ischemic stroke treatments as well. Our group is focused on creating smarter medical devices that can help the clinicians in treating these neurological disorders.