Wireless platforms for biomedical monitoring

IMEC and IMEC-Nederland at the Holst Centre created two body-monitoring wireless sensor nodes which collect and process data from human body sensors and wirelessly transmit the data to a central monitoring system.

The small size and low power consumption of both systems enables non-invasive and ambulatory monitoring of vital body parameters.

The company's two-channel bio-potential wireless sensor node targets the simultaneous monitoring of two vital body signs provided by portable electrocardiogram (ECG, which monitors the heart activity), electromyogram (EMG, which monitors muscle contraction), electroencephalogram (EEG, which monitors brain waves) and electrooculogram (EOG, which monitors eye movement).

The second system is an eight-channel wireless EEG system integrated in a cube. The small size and autonomy of the systems increase the patient¡¦s autonomy and quality of life and open up new applications for sports, entertainment, comfort monitoring, and other health and lifestyle products and services.

Both systems use the company's proprietary ultra-low-power bio-potential readout ASIC (application specific integrated circuit) to extract the bio-potential signals produced during the ECG, EMG, EEG or EOG measurements. The ASIC exists in a one-channel and an eight-channel version.

Features of the ASICs include: low power consumption of 60 µW for the one-channel version and 300 µW for the eight-channel version; suitable for a large spectrum of bio-potential signals, including EEG, ECG, EMG and EOG, by an electronic settable gain, electronic settable high cut-off frequency and externally adjustable low cut-off frequency; low noise; high common-mode rejection ratio (greater than 120 dB), which is required to cope with the large common-mode interference from which the uV-range signals suffer; capable of filtering 50 mVDC offset generated by the bio-potential electrodes.