SoC for Wearable Medical DevicesEngineering360 News Desk | October 06, 2016
A sensor hub integrated as a system-on-chip (SoC) has been developed for use in a range of wearable health devices.
Applications envisioned by designers from imec (Belgium) and The Holst Centre (The Netherlands) include patch monitors, chest band heart rate monitors, respiration or hydration monitors, and devices for blood-pressure calculation.
The SoC combines numerous biomedical analog interfaces into a single chip, on-board digital signal processing, high fidelity operation, and multi-day monitoring capability with a single battery. Biomedical analog interfaces include three ECG channels, photo-plethysmography (PPG), galvanic skin response (GSR), two multi-frequency bio-impedance (BIO-Z) channels to support new applications such as impedance-tomography, body fluid analysis and stroke volume measurements, and three reconfigurable channels. Due to its small form, the sensor hub may lend itself to device designs that enable maximum user comfort.
While high performance multi-modal analog readouts have been demonstrated, they lack on-board signal processing capabilities, or are too large in size. Alternatively, existing reconfigurable readouts are smaller, but have limited performance. Imec's and Holst Centre's SoC is claimed to move beyond current solutions and combines advanced biomedical readouts, supported by an ARM Cortex M0+ controller and accelerators for sample-rate conversion, matrix processing, data compaction, and power management circuitry (PMIC). The PMIC operates from a battery source (2.9- 4.5V) and generates the required voltages for the readout IC. The developers say it supports dynamic voltage scaling optimized for, but not limited to, low power and high performance applications, and can be customized for specific healthcare applications.