Researchers have created an innovative soft cortical device that has the potential to transform epilepsy treatment and manage other neurological conditions.
A dedicated team of researchers, led by Professors SON Donghee and SHIN Mikyung from the Center for Neuroscience Imaging Research (CNIR) at the Institute for Basic Science (IBS), alongside Dr. KIM Hyungmin from the Bionics Research Center at the Korea Institute of Science and Technology (KIST), has pioneered a soft cortical device that could change the landscape in treating epilepsy and various neurological disorders.
Epilepsy is a neurological disorder that impacts over 65 million individuals globally. It is marked by abnormal electrical activity in the brain that leads to seizures. Alarmingly, about 20-30% of patients experience intractable epilepsy, which does not respond to conventional medications. While surgical removal of lesions is an option for these patients, it involves complex procedures that carry risks.
An alternative method known as neuromodulation has been suggested. This technique involves directly stimulating damaged brain tissue using mechanical, electromagnetic, or optical energy to help alleviate brain hyperactivity. One notable method is transcranial focused ultrasound (tFUS) neurostimulation, a non-invasive approach that stimulates the brain with high accuracy without causing lasting damage.
For tFUS to successfully treat epilepsy, it needs to be connected to a system that can monitor brain activity continuously and modify treatment in real time. Existing devices that interface with the cortex struggle due to their rigidity and lack of adaptability to the brain’s irregular surface, leading to poor interaction between the device and the tissue. Their weak bonding to the brain’s surface also limits their ability to capture accurate brain signals during ultrasound stimulation, primarily due to disturbances created by mechanical pressure waves.
To tackle these issues, the research team introduced the Shape-Morphing Cortical-Adhesive (SMCA) sensor, a soft and flexible device that adheres tightly to the brain’s surface, ensuring consistent and precise monitoring of brain activity during tFUS stimulation. The SMCA sensor is made from a specialized combination of materials, including a layer of catechol-conjugated alginate hydrogel that rapidly bonds with brain tissue, providing excellent adhesion and minimizing movement or detachment. Furthermore, the device’s base is composed of a self-healing polymer that becomes softer and molds to the brain’s curves at body temperature, ensuring a comfortable fit and reducing signal disruptions.
The effectiveness of the SMCA sensor was tested in both ex vivo (outside the body) and in vivo (inside the body) experiments, comparing it to traditional devices that lack adhesive or shape-morphing capabilities. In trials using a rat model of epilepsy, the SMCA sensor successfully recorded brain activity during tFUS stimulation without interference, allowing for the real-time monitoring that is critical for effective treatment.
Utilizing this advanced sensor, the researchers created a closed-loop seizure control system. This system employs the SMCA sensor to detect early seizure activity and automatically adjusts the tFUS treatment accordingly. The system proved effective in suppressing seizures in real time, showcasing the potential for tailored, adaptive treatment for epilepsy.
Professor SON Donghee remarked, “Our research on this brain-adhesive soft bioelectronics platform has allowed us to overcome significant hurdles in brain interface technology by achieving high-quality electrocorticography alongside focused ultrasound stimulation without disruptive artifacts.” He elaborated on the importance of this research and revealed future aspirations, stating, “We foresee our technology becoming a foundational element of next-generation biomedical systems for accurate diagnosis and personalized treatment of difficult-to-treat neurological disorders. In future developments, we aim to enhance the SMCA sensor’s shape-morphing and adhesive properties, create highly integrated microelectrodes, and incorporate sophisticated closed-loop operational algorithms.”
Dr. Hyungmin KIM added, “We successfully detected seizure activity early through ECoG, which allowed for seizure prevention. We also established real-time feedback for the effects of ultrasound stimulation, facilitating personalized stimulation approaches. Looking ahead, we plan to develop electrodes with additional channels, along with multi-channel ultrasound transducers, to enhance seizure source mapping and intervention precision, ultimately improving the effectiveness and safety of this method in clinical settings.”
This collaborative research involved colleagues from Sungkyunkwan University (SKKU) and the Korea Institute of Science and Technology (KIST). The results were published in Nature Electronics on September 11, 2024.
