Rensselaer Researchers Develop Heat Spreader for Epileptic Seizure Treatment Device

Jul 26, 2005
Heat Spreader

Rensselaer Polytechnic Institute researchers are developing a tiny, highly efficient heat spreader to be used in a new device to be implanted in the brain of patients who suffer from severe epileptic seizures. The implant device is designed to detect and arrest epileptic seizures as they begin by cooling a small region of the brain, thereby effectively blocking the erratic electrical activity.

G. P. “Bud” Peterson, provost and professor of mechanical, aerospace, and nuclear engineering at Rensselaer, and his team are collaborating with researchers at Washington University School of Medicine in St. Louis to design, model, test, and develop the implant device. The research and the potential of the device are featured in the July 16 issue of New Scientist.

The heat spreader being developed at Rensselaer utilizes a phase-change heat process, the same mechanism that the human body uses to cool itself, to transfer and distribute heat in the brain. The fundamental principal behind the operation of the heat spreader is evaporation and condensation, similar to perspiration. Using a pure substance, saturated conditions are created inside the heat pipe, resulting in evaporation in the heated regions. Heat entering the pipe turns the liquid water to vapor, which is forced along the pipe by high pressure where it is condensed in the cooler regions. The dissipated heat is then pushed out of the heat pipe, and the wicking structure pumps the liquid back to the evaporator.

“The heat spreader we created for this implant device acts as a very efficient thermal conductor, spreading and releasing the heat without minimal temperature increase, thereby preventing any potential tissue damage to the brain,” said Peterson. “The brain can tolerate temperature reductions on the order of 18 to 20°C without sustaining permanent damage. However, the brain cannot tolerate temperature increases over 0.5°C. This requires that the heat both absorbed and generated by the device be spread across a much larger surface area.”

Implanted on the neocortex of the brain, close to where erratic electrical activity is causing the epileptic seizure, the implant device is designed to detect the unusual level of electrical activity that accompanies these types of seizures. The implant device then is activated to cool a small area of the brain from approximately 38°C (100°F) to 20°C (68°F) to render that part of the brain temporarily non-functional and seizure-free, according to researchers.

The implant device works as a very small “thermoelectric refrigerator,” approximately 0.25 inches on a side, consisting of many tiny metal semiconductor junctions connected between two ceramic electrodes to create an electronic circuit. The result is an implantable device in which one side is cooled and other is heated as electrical current moves through it. The heat spreader being developed by Peterson and his team, allows the heat generated and absorbed by the implant device to be effectively released without a significant increase in temperature.

The implant device has been successfully tested on rats and has been approved by the National Institutes of Health (NIH) for testing in primates. Researchers expect the device will provide a new methodology for the treatment of epileptic seizures in humans.

Peterson has conducted research on heat pipes and related two-phase heat transfer devices for 25 years, holds eight patents, and is the author or co-author of more than 145 peer-reviewed journal articles in fields as diverse as electronics and spacecraft thermal control, energy recovery systems, biomedical applications, and the cooling of valve stems in internal combustion engines.

Source: Rensselaer Polytechnic Institute

Explore further: Hackathon team's GoogolPlex gives Siri extra powers

add to favorites email to friend print save as pdf

Related Stories

The promise and peril of nanotechnology

Mar 26, 2014

Scientists at Northwestern University have found a way to detect metastatic breast cancer by arranging strands of DNA into spherical shapes and using them to cover a tiny particle of gold, creating a "nano-flare" ...

Spark: Look Ma, an open source thermostat

Jan 22, 2014

(Phys.org) —Spark.io has come up with an open source thermostat. "We spent about $70 on components to put this together (including $39 for the Spark Core); the wood and acrylic were free. We started working ...

Unlocking the brain's secrets using sound

Jan 22, 2014

(Phys.org) —The brain is a reclusive organ. Neurons the cells that make up the brain, nerves, and spinal cord communicate with each other using electrical pulses known as action potentials, but their interactions are complicated ...

Consumer product giants' eye-trackers size up shoppers

Jul 16, 2012

(Phys.org) -- Consumer product giants whose supply chains, profit margins, and boardroom reports depend on how fast the paper towels, shampoo, and diapers can fly off the shelves no longer dare to rely on ...

Recommended for you

Hackathon team's GoogolPlex gives Siri extra powers

4 hours ago

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

User comments : 0

More news stories

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...