Inexpensive and flexible nanographene-based electrodes for ubiquitous electrocardiogram monitoring

Flexible electronics is one of the fundamental technologies for the development of electronic skin, implant wearables, or ubiquitous biosensing. In this context, graphene-derived materials have attracted great interest due to their unique properties to fulfill the demands of these applications. Here we report a simple one-step method for the fabrication of electrophysical electrodes based on the photothermal production of porous nanographene structures on the surface of flexible polyimide substrates. This approach constitutes an inexpensive alternative to the commercial medical electrodes, leading to a lower and much more stable skin–electrode contact resistance and providing comparable signal transduction. This technology has been framed inside the IoT paradigm through the development of a denoising and signal classification clustering algorithm suitable for its implementation in wearable devices. The experiments have shown promising achievements regarding noise reduction, increasing the crest factor ~3.7 dB, as well as for the over 90% heart rate-monitoring accuracy.Cheap graphene electrodes for biosignal monitoringA cheap graphene foam electrode has been shown to deliver both accurate acquisition and efficient processing of biosignal to enable next generation medical and wearable devices. A team led by Dr Francisco Romero from University of Granada, Spain develops a one-step and inexpensive method to make electrophysical electrodes for biocompatible signal transduction. They employ low diode lasers to selectively induce highly porous structures in the graphene foam on a flexible substrate. When combined with a clustering algorithm, the graphene foam electrodes can effectively suppress the artifact and noise signals and extract heart beat pattern with more than 90% accuracy. These results present delicate balance between the high accuracy data acquisition and efficient data processing, which are both important for the elemental devices in the internet-of-things paradigm.

[1]  George G. Malliaras,et al.  Direct patterning of organic conductors on knitted textiles for long-term electrocardiography , 2015, Scientific Reports.

[2]  L. Castano,et al.  Smart fabric sensors and e-textile technologies: a review , 2014 .

[3]  Robert C. Wolpert,et al.  A Review of the , 1985 .

[4]  Wei Zhang,et al.  A Unified Framework for Street-View Panorama Stitching , 2016, Sensors.

[5]  Antonio García,et al.  A clustering-based method for single-channel fetal heart rate monitoring , 2018, PloS one.

[6]  G. De Backer,et al.  cardiovascular disease, and coronary heart disease death in men and women , 1998 .

[7]  Xuan Zeng,et al.  HeartID: A Multiresolution Convolutional Neural Network for ECG-Based Biometric Human Identification in Smart Health Applications , 2017, IEEE Access.

[8]  Jiangbin Wu,et al.  Raman spectroscopy of graphene-based materials and its applications in related devices. , 2018, Chemical Society reviews.

[9]  Fernando Costa,et al.  Primary Prevention of Cardiovascular Diseases in People With Diabetes Mellitus , 2007, Diabetes Care.

[10]  K. Park,et al.  Flexible polymeric dry electrodes for the long-term monitoring of ECG , 2008 .

[11]  Shuo Li,et al.  An Automatic Cardiac Arrhythmia Classification System With Wearable Electrocardiogram , 2018, IEEE Access.

[12]  Roger C. Barr,et al.  Skin-electrode impedance and its effect on recording cardiac potentials , 1966 .

[13]  K. Novoselov,et al.  All inkjet-printed graphene-based conductive patterns for wearable e-textile applications , 2017 .

[14]  Zaida Chinchilla-Rodríguez,et al.  Identification and Visualization of the Intellectual Structure in Graphene Research , 2017, Front. Res. Metr. Anal..

[15]  Adel Belouchrani,et al.  QRS detection based on wavelet coefficients , 2012, Comput. Methods Programs Biomed..

[16]  J. Tour,et al.  Laser-induced porous graphene films from commercial polymers , 2014, Nature Communications.

[17]  Alberto J. Palma,et al.  Efficient wavelet-based ECG processing for single-lead FHR extraction , 2013, Digit. Signal Process..

[18]  S. Dandapat,et al.  ECG signal denoising using higher order statistics in Wavelet subbands , 2010, Biomed. Signal Process. Control..

[19]  Sotaro Shimada,et al.  Simultaneous measurement of electroencephalography and near-infrared spectroscopy during voluntary motor preparation , 2015, Scientific Reports.

[20]  A. Gruetzmann,et al.  Novel dry electrodes for ECG monitoring , 2007, Physiological measurement.

[21]  Seiji Akita,et al.  Toward Flexible and Wearable Human‐Interactive Health‐Monitoring Devices , 2015, Advanced healthcare materials.

[22]  Junaidah Bte Mustafa Kamal.,et al.  Remote health monitoring. , 2013 .

[23]  Amr Mohamed,et al.  Efficient ECG Compression and QRS Detection for E-Health Applications , 2017, Scientific Reports.

[24]  W. Balachandran,et al.  Graphene-Enabled Electrodes for Electrocardiogram Monitoring , 2016, Nanomaterials.

[25]  J. Koo,et al.  Laser-Induced Graphene on Additive Manufacturing Parts , 2019, Nanomaterials.

[26]  Ramon Luengo-Fernandez,et al.  European Cardiovascular Disease Statistics 2017 , 2012 .

[27]  Chwee Teck Lim,et al.  Emerging flexible and wearable physical sensing platforms for healthcare and biomedical applications , 2016, Microsystems & Nanoengineering.

[28]  D. P. Morales,et al.  In-Depth Study of Laser Diode Ablation of Kapton Polyimide for Flexible Conductive Substrates , 2018, Nanomaterials.

[29]  Antonio García,et al.  Wearable System for Biosignal Acquisition and Monitoring Based on Reconfigurable Technologies , 2019, Sensors.

[30]  Yongsung Ji,et al.  Laser-induced graphene fibers , 2018 .

[31]  S. Barold Willem Einthoven and the birth of clinical electrocardiography a hundred years ago. , 2003, Cardiac electrophysiology review.

[32]  Zhaopeng Li,et al.  Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring , 2016, Sensors.

[33]  Pierre Vandergheynst,et al.  Compressed Sensing for Real-Time Energy-Efficient ECG Compression on Wireless Body Sensor Nodes , 2011, IEEE Transactions on Biomedical Engineering.

[34]  M. Sabarimalai Manikandan,et al.  Automated ECG Noise Detection and Classification System for Unsupervised Healthcare Monitoring , 2018, IEEE Journal of Biomedical and Health Informatics.

[35]  Tapas Mondal,et al.  Wearable Sensors for Remote Health Monitoring , 2017, Sensors.

[36]  Alberto J. Palma,et al.  Noise Suppression in ECG Signals through Efficient One-Step Wavelet Processing Techniques , 2013, J. Appl. Math..

[37]  Zijian Zheng,et al.  Wearable energy-dense and power-dense supercapacitor yarns enabled by scalable graphene–metallic textile composite electrodes , 2015, Nature Communications.

[38]  J. Webster,et al.  Dry electrodes for electrocardiography , 2013, Physiological measurement.

[39]  D. Basko,et al.  Raman spectroscopy as a versatile tool for studying the properties of graphene. , 2013, Nature nanotechnology.

[40]  Muhammad Mamdani,et al.  Next Steps in Primary Prevention of Coronary Heart Disease: Rationale for and Design of the ECAD Trial. , 2015, Journal of the American College of Cardiology.

[41]  A. Rivadeneyra,et al.  Design guidelines of laser reduced graphene oxide conformal thermistor for IoT applications , 2018 .

[42]  Sang-Hoon Lee,et al.  CNT/PDMS Composite Flexible Dry Electrodesfor Long-Term ECG Monitoring , 2012, IEEE Transactions on Biomedical Engineering.

[43]  Yong Zhu,et al.  Flexible Technologies for Self-Powered Wearable Health and Environmental Sensing , 2015, Proceedings of the IEEE.