DGIST develops technology to stimulate the brain with an ultra-small coil

□ DGIST(President Kunwoo Lee) announced that a research team led by Prof. Kim So-hee from the Department of Robotics and Mechanical Electronics has developed a technology that enables precise brain stimulation using a coil small enough to be implanted in the body. It is expected to be utilized as an electronic medicine for brain neurological disorders that require long-term treatment due to its ability to significantly improve safety and effectiveness with fewer side effects compared to existing technologies.

□ Brain-stimulating technologies are being used to treat Parkinson's disease and to aid in stroke rehabilitation. Currently, the most common method of brain stimulation involves passing a small electric current through the brain. This method requires the insertion of electrodes directly into the brain, which can cause damage to brain tissue, and in the long term, it can cause inflammation around the electrodes, reducing the stimulation effect.

□ Other non-contact brain stimulation methods use magnetic fields, such as transcranial magnetic stimulation (TMS), which is currently used clinically to treat depression. TMS involves placing a large magnet, 10 to 20 cm in size, over the head to generate a strong magnetic field that stimulates brain cells. However, as this method stimulates the entire head, the precision is low, and side effects such as headaches and dizziness can occur.

□ To address these limitations, Prof. Kim So-hee's research team has proposed a novel brain stimulation technology. The team developed a method capable of stimulating specific areas of the brain by placing an ultra-small coil (3.5 mm), approximately half the size of a pinkie nail, on the brain’s surface. This approach eliminates the need for a large device, as required by conventional TMS, and minimizes the risk of brain tissue damage by suppressing heat generation below a certain level.

□ The magnetic field generated by the coil is approximately 500 milliTesla (mT), about 10 times stronger than the Earth's magnetic field, which is approximately 50 microTesla (µT). For reference, the Earth's magnetic field is strong enough to move a compass needle, and the magnetic field from this coil is stronger but still within a safe range. This low magnetic field allows for effective stimulation while increasing safety. The method has demonstrated both the effectiveness and precision of the stimulation—an achievement that surpasses existing magnetic stimulation methods, which do not allow for precise stimulation.

□ The technology developed in this study is expected to be used for treating various neurological diseases and for neurorehabilitation. In particular, since it facilitates precise stimulation of specific parts of the brain without penetrating brain tissue, it can be used in various areas such as stroke rehabilitation and symptom relief for movement disorders such as Parkinson's disease. It is also expected to evolve into a self-treatment type of electronic medicine, ushering in an era where people can easily receive brain stimulation treatment at home without the need to visit a hospital.

□ "We have shown that precise brain stimulation is possible without damaging brain tissue in localized areas using millimeter-sized coils, which will overcome the disadvantages of TMS treatment, such as the need for regular hospital visits and calibration work to set the coil and stimulation parameters each time," said Prof. Kim, emphasizing the significance of the results.

□ Prof. Kim So-hee is the corresponding author of this study, and Dr. Lee Jeong-jae, a postdoctoral researcher at the Massachusetts General Hospital in Boston, USA, is the first author. This study is an outcome of the Future Challenging Defense Technology Research and Development Program (No. 915069201) supported by the National Defense Research Institute with the 2022–2027 government fund (Defense Acquisition Program Administration). The study was published as a cover article in Brain Stimulation, a leading international journal in the field of clinical neurology.

- Corresponding Author E-mail Address : soheekim@dgist.ac.kr