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 mm2 silicon area.

[1]  Yong Lian,et al.  A 300-mV 220-nW Event-Driven ADC With Real-Time QRS Detection for Wearable ECG Sensors , 2014, IEEE Transactions on Biomedical Circuits and Systems.

[2]  Yong Lian,et al.  A 1-V 450-nW Fully Integrated Programmable Biomedical Sensor Interface Chip , 2009, IEEE Journal of Solid-State Circuits.

[3]  Ameya Bhide,et al.  A 53-nW 9.1-ENOB 1-kS/s SAR ADC in 0.13-$\mu$m CMOS for Medical Implant Devices , 2012, IEEE Journal of Solid-State Circuits.

[4]  Sameer R. Sonkusale,et al.  An Adaptive Resolution Asynchronous ADC Architecture for Data Compression in Energy Constrained Sensing Applications , 2011, IEEE Transactions on Circuits and Systems I: Regular Papers.

[5]  R. R. Harrison,et al.  A low-power low-noise CMOS amplifier for neural recording applications , 2003, IEEE J. Solid State Circuits.

[6]  Wouter A. Serdijn,et al.  A Sub-Microwatt Asynchronous Level-Crossing ADC for Biomedical Applications , 2013, IEEE Transactions on Biomedical Circuits and Systems.

[7]  Amir M. Sodagar,et al.  Analysis and Design of Tunable Amplifiers for Implantable Neural Recording Applications , 2011, IEEE Journal on Emerging and Selected Topics in Circuits and Systems.

[8]  David Blaauw,et al.  An Injectable 64 nW ECG Mixed-Signal SoC in 65 nm for Arrhythmia Monitoring , 2015, IEEE Journal of Solid-State Circuits.

[9]  Reza Lotfi,et al.  A linear tunable amplifier for implantable neural recording applications , 2011, 2011 IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS).

[10]  Xin Liu,et al.  An Ultra-Low Power ECG Acquisition and Monitoring ASIC System for WBAN Applications , 2012, IEEE Journal on Emerging and Selected Topics in Circuits and Systems.

[11]  Reza Lotfi,et al.  A fully-synchronous offset-insensitive level-crossing analog-to-digital converter , 2016, 2016 IEEE 59th International Midwest Symposium on Circuits and Systems (MWSCAS).

[12]  S. Sonkusale,et al.  Adaptive asynchronous analog to digital conversion for compressed biomedical sensing , 2009, 2009 IEEE Biomedical Circuits and Systems Conference.

[13]  Reza Lotfi,et al.  A Level-Crossing Based QRS-Detection Algorithm for Wearable ECG Sensors , 2014, IEEE Journal of Biomedical and Health Informatics.

[14]  Reid R. Harrison,et al.  The Design of Integrated Circuits to Observe Brain Activity , 2008, Proceedings of the IEEE.

[15]  Reid R. Harrison,et al.  A low-power, low-noise CMOS amplifier for neural recording applications , 2002, 2002 IEEE International Symposium on Circuits and Systems. Proceedings (Cat. No.02CH37353).

[16]  Zhe Zhang,et al.  A 2.89 $\mu $ W Dry-Electrode Enabled Clockless Wireless ECG SoC for Wearable Applications , 2016, IEEE Journal of Solid-State Circuits.

[17]  Reza Lotfi,et al.  Detailed study of the time estimation in level-crossing analog-to-digital converters , 2013, 2013 21st Iranian Conference on Electrical Engineering (ICEE).

[18]  Antonio Torralba,et al.  A new family of very low-voltage analog circuits based on quasi-floating-gate transistors , 2003, IEEE Trans. Circuits Syst. II Express Briefs.