Tripolar Flexible Concentric Ring Electrode Printed with Inkjet Technology for ECG Recording

Laplacian potential on the body surface can be estimated by means of concentric ring electrodes. It has been proved that bioelectrical surface recordings performed with such concentric ring electrodes improve spatial resolution compared to unipolar or bipolar disc electrodes. However, concentric ring electrodes have commonly been implemented in rigid substrates. Therefore they do not adapt to the body surface curvature what provokes discomfort to the patient and a poor contact that affects the signal quality. The aim of this work was to develop a new active concentric ring electrode on a flexible substrate for obtaining high spatial resolution ECG recording. Specifically the active electrode is made up of a disposable tripolar concentric ring electrode printed onto polyester film using inkjet technology, and a reusable signal preconditioning circuit. Simultaneous laplacian ECG recordings with the developed electrode and reduced Lead-I ECG with conventional disc electrodes were conducted in 7 subjects. The results show that the flexible active sensor can be used for picking up laplacian ECG with a similar signal quality than standard Lead-I ECG. This sensor could be used for ECG monitoring with enhanced spatial resolution.