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.
