Electronic Design
Holey Helmet Reads Minds

Holey Helmet Reads Minds

Again the tech sector seems to prove that it can create whatever the human mind envisions. On March 23, 2010 at the Medtech Conference in Stuttgart, Germany, Imec, the Holst Centre, and the laboratory of Neuro- and Psychophysiology at the Katholieke Universiteit Leuven unveiled a prototype of what they call the Mind Speller.

According to its creators, Mind Speller is an electro-encephalogram (EEG)-based device that allows persons with speech and/or language disorders, brain paralysis, and other motoric disabilities to communicate by interpreting their brain waves to spell words and phrases. Essentially, it detects and interprets P300 potentials in the EEG-signals of a person selecting characters from a display with alternate rows and columns of characters. The prototype consists of a flexible, easy-to-wear helmet (see the photo) with holes for fitting electrodes at various positions on the subject’s head.

Reportedly, the employment of P300 potentials as metrics of cognitive functioning in decision making processes is not uncommon. Currently available P300 devices, however are large, expensive, and both cumbersome and uncomfortable for the end user. On the flipside, Mind Speller employs a portable device not larger than a matchbox, which connects to the helmet to capture relevant EEG signals. Developed by Imec and Holst Centre, electronics in the box consist of a proprietary ultra-low power, eight-channel EEG-chip, a commercially available microcontroller for digitizing the EEG signals, and a low-power, 2.4-GHz radio that transmits EEG signals to a local Windows computer.

On the computer end, interpretation of input data is via comprehensive and robust signal-processing algorithms. These are the work of Professor Marc Van Hulle and his team at the laboratory of neuro- and psychophysiology of the Katholieke Universiteit Leuven.

In contrast to Mind Speller, there are several technologies currently available for people with severe impairments. Some of these rely on either eye-tracking technology or laser pointing. Although accurate, they are allegedly subject to long and delicate calibration procedures and very expensive due to the requirements for custom configurations.

Addressing these situations, Professor Van Hulle points out that “Mind Speller is a generic device that can easily be adjusted to different users. Therefore, it could become a cost-efficient communication solution for people with temporal impairments for whom the existing solutions are too expensive”. Chris Van Hoof, Program Director of Human++ at Imec amplifies, “With a much simpler design, relying on a power-efficient on-chip implementation, Mind Speller is the first step in the development of a generic, easy-to-wear, accurate and cost-efficient communication solution for people with motoric disabilities. Currently, we are adapting the electronics to work with dry electrodes to make the system even more unobtrusive”.

For further information about Mind Speller, contact Katrien Marent, Imec’s Director of External Communications via email at [email protected] or Professor Marc Van Hulle at [email protected]. To see Mind Speller in action, a video is available at http://www.youtube.com/watch?v=4sWzNcVwphI&feature=player_embedded.

TAGS: Components
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