A field-referenced surface electrode for biosignal detection

Biopotential measurements for clinical diagnostics and brain-machine interface are usually carried out by placing multiple electrodes to the target areas. Due to the non-invasiveness, ease of deployment, and relatively simpler manufacturing, surface electrodes have found immense number of applications. This work presents a field-referenced surface electrode for the measurement of surface potentials. Each electrode can be addressed by applying a constant reference signal on the field plate and the corresponding induced potential is measured from the sensing plate. The reference-biased field plate shields the sensing plate from tangential field lines and interference from the neighboring electrodes. Due to the presence of the reference signal, the electric field originating from a biological source crowds towards the referenced-field plate and impacts the induced potential in the sensing plate. Simulation results indicate the better selectivity performance of the proposed structure.