A study on reception electrodes for the vital-sign monitor using near-field intra-body communication enhanced by spread spectrum technique

As a novel vital sign monitor, we have developed wireless ECG monitoring system with Near-field intra-body communication (NF-IBC) technique. However, it was hard to ensure communication reliability because transmission channel is noisy and unstable. In order to solve the problem, we utilize spread spectrum (SS), which is known as robust communication technique even through poor transmission channel. In previous study, we have already developed an ECG monitor using NF-IBC enhanced by SS. In this paper, we evaluated on structure of the reception electrode for reliable communication. Based on the evaluations with bit error rate, we suggested the reception electrode structure which can keep the communication reliability. As the results we considered that we can expand the reception electrode up to 2.25m². Moreover, we proposed the structure of the reception electrodes that can keep the communication reliability. Finally we suggested how to use the SS NF-IBC vital-sign monitor in room that larger than 2.25m², and we had shown the practicability of the systems.