Reusable electrical activity of the heart monitoring patch for mobile/ubiquitous healthcare.

In order to monitor electrical activity of the heart during daily life, we present an electrode of a medical instrument system which is able to measure the body surface potential difference by minimizing the electrode distance. The designed electrode is composed of concentric circles. It was made from the basis of the Laplacian equation, and implemented on PCB coated with gold. So that it does not cause the uncomfortable feeling of contact and possible skin troubles which are typical shortcoming of the conventional ECG measurement. The suggested method utilized three concentric circles on FR-4 substrate, so new amplifier design regarding measuring of small biological signal, is considered which has the characteristics of asymmetric input impedance since the area of concentric circular ring electrodes is not identical. Thereby, electrical activity of the heart was obtained successfully. However, its signal quality is a little bit degraded and the motion artifact still remains as a major problem as is in conventional electrocardiography measurement. Certainly stable measurement setup was needed to reduce the motion artifact originated from variation in static electricity between skin and electrode interfaces.