Application of Near-field intra-body communication and spread spectrum technique to vital-sign monitor

As a novel vital sign monitor, we have developed wireless ECG monitoring system with Near-field intra-body communication technique. However, communication reliability is not so high because transmission channel is noisy and unstable. In order to improve the problem, we utilize spread spectrum (SS), which is known as robust communication technique even through poor transmission channel. First of all, we evaluated characteristics of human body to SS signal. The results show that SS can be used even through human body. Based on this result, we developed and tested near-field intra-body communication device enhanced by SS. The test result shows that SS can solve the problem mentioned above.