An event-based ECG-monitoring and QRS-detection system based on level-crossing sampling

A complete event-based ECG monitoring and QRS-detection system is designed and implemented which is working based on level-crossing sampling. The system contains an analog front-end including a three-stage band-pass filter and variable-gain amplifier, a single-path level-crossing analog-to-digital converter (SP-LCADC) and a QRS-detector digital core which is working directly using level-crossing sampled data. Using SPL-CADC, the design of analog-front-end is relaxed by reducing the current which is drawn from the output of the front-end amplifier. Also, the ADC occupied silicon area is considerably saved and one of the ADC bottle-neck non-idealities is relaxed which is the mismatch between the comparators offsets. The event-based property of the system leads to an extra low power consumption, which is 449 nW for 1.8 V supply voltage based on the post-layout simulation results using a 0.18 μm CMOS process. The system occupies 0.164 mm
²
silicon area.