IMEC and its Dutch
subsidiary Holst Centre have constructed
an 8-channel wireless electroencephalograph (EEG) for monitoring
patients in their daily environment.
Previously, patents had to be connected to fixed equipment by
multi-wire cables.
Applying the equipment has been simplified by using dry, rather
than gel or adhesive, electrodes; and mounting them in a headset
which also includes a 10m range wireless link.
Key to the design is an 8-channel front-end chip with a 11bit
ADC that provides 120dB common-mode rejection and 60nV/[square root
symbol]Hz noise per channel, plus full auto-calibration, all for
200µW power consumption.
The rest of the electronics, which fit on a 47x27mm PCB, are a
Texas Instruments MSP430 MCU and a
Nordic Semiconductor nRF24L01 transceiver - a combination that
is used in all Holst Centre wireless medical sensor nodes.
The packaged system consumes 1.8mA, allowing over three days of
autonomy with a 160mAh Li-ion battery.
To demonstrate ease of headset use, IMEC has commissioned a
public work
of art (pictured below) that makes sounds
depending on the brain activity of the wearer, who is anyone off
the street that dons the headset.
