A microfabricated electrode with hollow microneedles for ECG measurement

This paper proposes a novel micromachined physiological recording electrode with hollow microneedles for electrocardiography (ECG) measurement. Compared to the standard commercial wet electrode, a unique characteristic of this device is that a hollow microneedle array, which is made of silicon, can pierce through the outer skin surface, lowering the electrode-skin-electrode impedance (ESEI) and eliminating the need for skin preparation. Furthermore, instead of the conventional electrolytic gel, NaCl solution is used to fill the hollow microneedles and the reservoir etched in the backside of the silicon die; it is more comfortable, easy to acquire and imposes no side-effects on human. Test results of this electrode showed that this device could acquire typical structures of ECG signal with high signal to noise ratio, which provides a potential for routine and repetitive measurement with convenience, and comfort for home health care management of aged population.