In spite of the significant progress in technologies for industrial robotics and the emergence of robots for household chores, little has been done in the field of orthoses and prostheses to daily assist disabled patients who lost the control of a limb. Prostheses based on electromyographic (EMG) signals (i.e. the electrical signals produced by the muscle activity) are available on the market but they present some drawbacks, notably the fact that they are able to correct but not anticipate a motion.
The project aims at studying and developing an orthosis control system exploiting EEG signals or a combination of both EEG and EMG signals. It mobilizes competences in neurophysiology, micro-electronics, mechanics and rapid manufacturing. The technological innovation is present throughout the different steps of the process, from the acquisition of EEG signals, to processing, transmission, control and motorization, energy management and comfort for the patient.
The role of CETIC in this project is to study and develop an embedded platform exploiting the EEG signals to control the orthosis and using wireless communication protocols. The focus is on the autonomy (low energy consumption) and portability (by a human being) aspects.
More precisely, CETIC aims at:
- implementing on an electronic card an artificial neural network, of DRNN (Dynamic Recurrent Neural Network) type, developed by the academic partners of the project;
- developing a low-power wireless network to transmit EEG signals and control data between the different parts of the system (EEG wireless headset, neural network, orthosis controller, orthosis).
In 2011, the project partners have notably prototyped a wireless EEG headset. As far as CETIC is concerned, it has developed a battery-powered printed circuit board (PCB) located in a small box attached to that headset at the rear of the head. The PCB acquires the signals of EEG electrodes and wirelessly transmits the EEG data using a ZigBee-like protocol to another PCB located at the level of patient’s leg (this latter PCB will be developed in 2012 and will include the DRNN). The developed PCB calls on techniques and components to guarantee a very good immunity to disturbances induced by external and internal noise sources.
Added Values for Businesses
The application fields of the research are multiple.
All the knowledge and procedures related to the acquisition and processing of EEG signals can contribute to enhancing the quality of life of people with mobility impairments. In addition to the design of intelligent orthoses, other applications are possible such as the driving of wheelchairs controlled by human brain.
Moreover, because this project also relates to brain-computer interfaces, the future application fields can potentially be broader and interest non-disabled human beings. The interpretation of brain signals could be for instance of major interest for road safety. Other applications are in the field of remote controls of robots, machines…
CETIC will also be able to exploit the experience it acquired in the implementation of neural networks and in the design of portable and low-power wireless communication systems to offer new services to Walloon SMEs.