LONDON — Research organization IMEC (Leuven, Belgium) could extend its investigations into wireless electroencephalography (EEG) to enable measures of emotion to be fed back into computer games, according to Bert Gyselinckx, program director for wireless autonomous transducer solutions at IMEC's Dutch outpost at the Holst Center (Eindhoven, Netherlands).

This could, conceivably, allow measurements of players' excitement, happiness or sadness, to be used as inputs for games * or more serious computer programs. At a simple level it could be used to change a through-character's facial expression between happy and sad. At a more sophisticated level a quantified measure of excitement could be used to change the rapidity with which a game character responds to commands; the more excited the player becomes, the quicker the game character can execute game moves.

On a more serious level one could conceive of an automobile driving assistant providing feedback that a user is too tired or emotional to drive a vehicle.

Gyselinckx discussed a two-channel wireless brain wave monitoring system powered by a thermo-electric generator at a press briefing ahead of IMEC's Annual Research Review Meeting held last month in Leuven, Belgium. It uses the body heat dissipated naturally from the forehead as a means to generate its electrical power. The wearable EEG system operates autonomously with no need to change or recharge batteries. This is a major advantage for body-worn sensors, a key theme in the Human++ program within the Holst Center.

The system was demonstrated at the press briefing with a wireless connection used to send brain wave data from one of the researchers to a notebook computer. When asked if IMEC would look into using EEG data as part of a biofeedback loop to control consumer equipment or vehicles, Gyselinckx said IMEC was not considering doing this in a simple manner - cursor or joystick control.

That field is developing rapidly as a means of providing quadriplegic sufferers with greater control of their environment, as a means of providing fighter pilots with a control mechanism that could be faster than the hand for specialized tasks, and as a control option for the cursor on a games screen or in an immersive video environment.

However, Gyselinckx said IMEC researchers were considering how to put emotion, deduced from EEG traces, into the gaming environment.

IMEC's EEG monitor prototype is wearable and integrated into a headband where it consumes 0.8 milliwatts. Potential applications are detection of imbalance between the two halves of the brain, detection of certain kinds of brain trauma and monitoring of brain activity. The system uses IMEC's proprietary biopotential readout ASIC to extract EEG signals. A DSP block encodes the extracted EEG data which is sent to a PC via a 2.4-GHz wireless radio link.

The thermoelectric generator is mounted on the forehead and converts the heat flow between the skin and air into electrical power. The generator is composed of 10 thermoelectric units interconnected in a flexible way. At room temperature, the generated power is about 2 to 2.5-mW or 0.03-mW per square centimeter, which is the theoretical limit of power generation from the human skin. Higher power generation would cause an uncomfortable sense of cold.

Future hardware research targets further reduction of the power consumption in the radio and processor. A semiconductor process for manufacturing thermopiles is under development. Companies interested in licensing the technologies are being encouraged to join the Human++ industrial affiliation program.

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