Development of Contactless Dry ECG Electrodes for Long-Term Monitoring

Abstract

An ECG (Electrocardiogram) is a convenient tool to access information about the cardiovascular functions of the heart. Cardiovascular diseases have become one of the major causes of death globally. Hence, continuous and long-term monitoring of heart signals is very much required. Researchers proposed both the contact and non-contact measurements of ECG using different types of dry electrodes or sensors. It is emerging as an effective alternative. Clinically, wet electrodes, i.e., Ag/AgCl electrodes, are used. This isn't feasible for long-term continuous monitoring of the heart because it requires conductive or electrolyte gel for placement of electrodes, which dries up with time, leading to signal distortion and may also cause skin irritations. Keeping in view the advantages of dry electrodes over conventional electrodes, this paper reports the development and analysis of dry electrodes that may replace those conventional Ag/AgCl electrodes that require electrolyte gel. In this work, we have fabricated two types of dry electrodes with specific techniques, named “textile electrode” and “silver button electrode,” respectively. These electrodes are connected to the subject's body with the help of a Velcro strap that extracts the heart signal from the body. The obtained signal is also compared with the clinical ECG of the same subject body obtained using 12 lead electrodes, the conventional method. The results obtained are analyzed and we have found them promising and acceptable for the calculation of various required parameters for diagnostic purposes.