High-performance sensor attached to the brain, resolution 100 times higher than conventional;

Dense grid with 1024 or 2048 ECoG sensors embedded

``Human brain mapping with multithousand-channel PtNRGrids resolves spatiotemporal dynamics'' developed by a research team from the University of California, San Diego, Oregon Health and Science University, and Massachusetts General Hospital, 1024 or 2048 cortical EEG recordings (ElectroCorticoGram, ECoG) It is a thin and flexible sheet-like electrode (grid) with a dense array of sensors. [Image] PtNR grid is attached to the surface of the brain to capture the electrical signals of the brain. Considering the number of sensors in the ECoG grid, which is currently commonly used in surgery, is 16 to 64, and 256 for research, it is said that it is possible to acquire electrical signals of the brain with a resolution 100 times higher than the current one. The method of capturing brain signals using the ECoG grid is to place the ECoG grid between the bottom of the skull and the brain surface and measure from the cerebral cortex surface. It's not over your head, nor does it penetrate into your brain, but it's an approach in between. It is already a common tool used by surgeons to remove brain tumors and treat epilepsy in people who do not respond to drugs and other treatments. With this approach, the ability to record high-resolution brain signals will allow surgeons to remove many brain tumors while minimizing damage to healthy brain tissue. In the case of epilepsy, the ability to record brain signals at higher resolution would allow surgeons to pinpoint brain regions where epileptic seizures are occurring, and to identify nearby brain areas not involved in seizure generation. You can remove an area without touching it. This time, we will develop a thin ECoG grid that has these advantages and aims to achieve higher spatial resolution and expand the range of the cerebral cortex. This ECoG grid utilizes Microelectromechanical systems (MEMS) technology and newly developed highly biocompatible platinum rods (PtNR). Using platinum-based sensors to record the electrical activity of neurons in the brain is not new, but nanoscale rods are. The nanorod shape provides a larger sensing surface area than a flat platinum sensor, which helps increase the sensitivity of the sensor.　The ECoG grid is made by incorporating an electrode array on an 18 x 18 square cm substrate. The sensing area is 8 x 8 square cm (2048 channels) and 3 x 13 square cm (1024 channels). Embedded in a transparent, soft, biocompatible material called parylene, they are 10 micrometers thick, 100 times thinner than the clinically accepted 1 mm ECoG grids. The electrical signal travels from the brain through the cerebrospinal fluid and reaches the exposed surface of the platinum nanorods embedded in parylene. In the experiment, human recordings were performed using a 1024-channel PtNR grid obtained from 19 subjects and a 2048-channel PtNR grid obtained from one subject. As a result, we succeeded in capturing fine and complex signals from the surface of the cerebral cortex of an awake patient performing a grasping task. Furthermore, we discriminated the spatial spread and movement of epileptic discharges in patients undergoing epilepsy surgery with a spatial resolution of 1 mm.　The long-term plan is to develop a wireless version of this ECoG grid so that it can be used for monitoring the brains of patients with intractable epilepsy for up to 30 days. They also want to explore the potential of implantable approaches to improve the quality of life for people with paralysis and other neurodegenerative diseases that can be treated with electrical stimulation, such as Parkinson's disease, essential tremor and dystonia. Source and Image Credits: Youngbin Tchoe, Andrew M. Bourhis, Daniel R. Cleary, Brittany Stedelin, Jihwan Lee, aren J. Tonsfeldt, Erik C. Brown, Dominic A. Siler, Angelique C. Paulk, Jimmy C. Yang, Hongseok Oh, Yun Goo Ro, Keundong Lee, Samantha M. Russman, Mehran Ganji, Ian Galton, Sharona Ben-Haim, Ahmed M. Raslan, and Shadi A. Dayeh. “Human brain mapping with multithousand-channel PtNRGrids resolves spatiotemporal dynamics” SCIENCE 19 Jan 2022, Vol 14, Issue 628. DOI: 10.1126/scitranslmed.abj1441

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* Written by Hiroki Yamashita, who presides over the web media "Seamless" that introduces the latest research in technology. Mr. Yamashita picks up highly novel scientific papers and explains them.

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