Smart SWCNT ECG Electrodes for Continuous and Long-term Monitoring

Flexible and stretchable electronics have given this world a splendid opportunity to monitor and manage their own health. This has led to a convenience-based and versatile form of health monitoring, via smart sensors. These smart sensors can be used to measure various health parameters like respiration rate, ECG (Electrocardiogram), EEG (Electroencephalogram), EMG (Electromyography), blood pressure, etc. These portable sensors allow people to monitor their health status more comfortably and adequately, compared to using bulky devices. These smart sensors can be developed due to the advent of nanomaterials and nanoparticles. All thanks to the developments in the domain of nanoelectronics, we can now gauge various physiological parameters anywhere and everywhere. Using nanocrystalline materials not only reduces the size of the system but also increases the stability, sensitivity and response time of the system. Nanomaterials like Graphene, Carbon Nanotubes (CNTs), Silver Nanowires (AgNWs), Carbon Black, etc. are already in use. However, it is CNTs, which can be utilized to fabricate the smart sensors, that are most popular, and in universal demand. These sensors are highly required in the world today. Time or financial constraints prevent people from visiting a hospital for a medical checkup. Additionally, in many countries there is a lack of medical infrastructure, i.e., either the doctor(s) are not present, or medical devices are not available. Such limitations lead to an increase in the death toll, especially for people suffering from heart diseases. Since cardiovascular diseases (CVDs) are unpredictable in nature, they can occur anytime and anywhere. It is imperative for one to have access to medical facilities in order to save himself/herself. In order to bring this system to life, smart materials need to be incorporated in the ECG monitoring systems. In this paper, we review various SWCNT (Single-Walled Carbon Nanotubes) based ECG electrodes.