You are here : Home > Brain Computer Interface (BCI)

Articles & files | Focus | Article | Health & life sciences


Brain Computer Interface (BCI)

Recoding and decoding the cortex's electrical activity to enable severely motor-handicapped persons to control complex systems.

Published on 2 March 2017

Capturing and decoding the electrical activity of the cortex

What is BCI? 
The aim of the BCI project, led by CLINATEC®'s Professor Alim-Louis Benabid, is to provide proof that a 4 limb exoskeleton can be controlled using cortical signals recorded chronically by an implantable medical device called WIMAGINE® and to thereby offer future prospects to motor-handicapped people.


The principle behind the BCI is based on the fact that imagining or executing a movement stimulates the same brain electrical activity in the motor cortex. The aim of the BCI project is to record electrical signals called ElectroCorticoGrams (ECoG), then to decode them to control complex objects, for example moving the limbs of an exoskeleton.

How does this work?
The subject placed in the exoskeleton can control it by imagining movements as if he/she was going to execute them himself/herself! The brain activity resulting of the subject’s intentionally imagined movement is recorded by WIMAGINE® implants located on the left and right of the person's motor cortex and is decoded to control the exoskeleton's arm and leg joint motors.



Click to enlarge


Applications: 
This project offers prospects of innovative functional substitution solutions that will ensure an enhanced quality of life for severely motor-handicapped persons. 


What’s new?
We are the first in the world to develop an Implantable Medical Device, WIMAGINE®, to capture the motor cortex's electrical activity. This device measures ElectroCorticoGrams using an array of 64 electrodes in long-term contact with the dura mater. The WIMAGINE® implant is composed of integrated circuits (ASICs) that measure the neuronal signals,  wireless transmission module and remote supply antennas, as well as hermetic, biocompatible medical packaging. 

The ECoG signalscaptured by this device are then decoded in real time using innovative algorithms (developed to process huge data volumes) to predict the subject's intentionally imagined movement and control the exoskeleton. The EMY exoskeleton incorporates 14 motors that control the structure's 4 limbs (2 arms with 4 degrees of freedom each and 2 legs with 3 degrees of freedom each), and onboard PCs dedicated to processing the signal and controlling the system. It is battery-powered and therefore energy independent.  

This BCI platform comprising the WIMAGINE® implant, the decoding software and the EMY exoskeleton complies with European directives on Class III AIMDs for use in clinical trials. Professor Alim-Louis Benabid, Lead Investigator for the "BCI and Tetraplegia" Clinical Research Protocol has been authorized by Grenoble University Hospital's clinical research and innovation division (DRCI) and by the French regulatory agency governing drugs and health products (ANSM) and the  ethical committee  (CPP) to start the clinical trial at Clinatec®.


Video in french: