A Fully Implantable Wireless ECoG 128-Channel Recording Device for Human Brain–Machine Interfaces: W-HERBS

Publication Title
Frontiers in Neuroscience
Publication/Creation Date
July 30 2018
Kojiro Matsushita (creator)
Masayuki Hirata (creator)
Takafumi Suzuki (creator)
Hiroshi Ando (creator)
Takeshi Yoshida (creator)
Yuki Ota (creator)
Fumihiro Sato (creator)
Shayne Morris (creator)
Hisato Sugata (creator)
Tetsu Goto (creator)
Takufumi Yanagisawa (creator)
Toshiki Yoshimine (creator)
Osaka University (contributor)
Hiroshima University (contributor)
Tohoku University (contributor)
Oita University (contributor)
Gifu University (contributor)
Media Type
Journal Article
Persuasive Intent
Abstract: Brain–machine interfaces (BMIs) are promising devices that can be used as neuroprostheses by severely disabled individuals. Brain surface electroencephalograms (electrocorticograms, ECoGs) can provide input signals that can then be decoded to enable communication with others and to control intelligent prostheses and home electronics. However, conventional systems use wired ECoG recordings. Therefore, the development of wireless systems for clinical ECoG BMIs is a major goal in the field. We developed a fully implantable ECoG signal recording device for human ECoG BMI, i.e., a wireless human ECoG-based real-time BMI system (W-HERBS). In this system, three-dimensional (3D) high-density subdural multiple electrodes are fitted to the brain surface and ECoG measurement units record 128-channel (ch) ECoG signals at a sampling rate of 1 kHz. The units transfer data to the data and power management unit implanted subcutaneously in the abdomen through a subcutaneous stretchable spiral cable. The data and power management unit then communicates with a workstation outside the body and wirelessly receives 400 mW of power from an external wireless transmitter. The workstation records and analyzes the received data in the frequency domain and controls external devices based on analyses. We investigated the performance of the proposed system. We were able to use W-HERBS to detect sine waves with a 4.8-μV amplitude and a 60–200-Hz bandwidth from the ECoG BMIs. W-HERBS is the first fully implantable ECoG-based BMI system with more than 100 ch. It is capable of recording 128-ch subdural ECoG signals with sufficient input-referred noise (3 μVrms) and with an acceptable time delay (250 ms). The system contributes to the clinical application of high-performance BMIs and to experimental brain research.
HCI Platform
Discursive Type
Location on Body
Marketing Keywords

Date archived
July 30 2018
Last edited
July 31 2018
How to cite this entry
Kojiro Matsushita, Masayuki Hirata, Takafumi Suzuki, Hiroshi Ando, Takeshi Yoshida, Yuki Ota, Fumihiro Sato, Shayne Morris, Hisato Sugata, Tetsu Goto, Takufumi Yanagisawa, Toshiki Yoshimine. (July 30 2018). "A Fully Implantable Wireless ECoG 128-Channel Recording Device for Human Brain–Machine Interfaces: W-HERBS". Frontiers in Neuroscience. Frontiers. Fabric of Digital Life. https://fabricofdigitallife.com/index.php/Detail/objects/3097