Polymer-based dry electrodes for high user comfort ECG/EEG measurements

Conventional ECG and EEG gel electrodes are widely used in health care applications. These electrodes deliver high-quality signals due to their low impedance, but they have important drawbacks, such as time-consuming electrode set-up for EEG followed by a painful removal, skin irritation by the gel, signal degradation due to drying of the gel, etc. To solve this, various types of dry electrodes attract attention last years. Hard metal dry electrodes show low impedance, but most are not comfortable for the patient. Flexible polymer-based electrodes are presented in this work to avoid the disadvantages of gel electrodes while significantly improving user comfort. Different additives are mixed in these polymers and optimized to improve various relevant properties. An important electrode property is low impedance, which directly affects signal quality and influences the sensitivity to motion artifacts. The polymer composition influences also the mechanical properties, as well as the material flow during molding and hence the electrode fabrication yield. Moreover, various electrode shapes are tested to achieve appropriate mechanical properties and increase user comfort. For ECG & EEG applications, the best performing dry electrodes are selected and results are compared with wet electrode signals