A wearable wireless ECG sensor with real-time QRS detection for continuous cardiac monitoring

As we progress into the dawn of wireless health, wearable bio-medical sensor designers are facing great challenges in improving power efficiency and minimizing device size. System level design plays a vital role in addressing these challenges as it has a bird-eye view of constraints in the power management scheme in the hardware and software co-design ecology. This paper presents the design considerations for a wearable wireless electrocardiogram (ECG) sensor targeting for continuous monitoring of cardiac patients. The system consists of a data acquisition front-end, a low-power 8-bit microcontroller, 2GB of flash memory, a Bluetooth transceiver, and a power management unit. It is shown that system level optimization results to power reduction of about 99%, enabling at least 1 months of operation on a typical cell phone battery of 650mAH with occasional Bluetooth usage.