A wireless medical biosensor using Human Body Communication(HBC)for data transmission is presented in this paper. HBC is included in the IEEE Standard 802.15.6 for Local and Metropolitan Area Network and presents the characteristic of being a new non-radio frequency type of wireless communication as it uses the human body as a transmission medium. The multiple access technique should be Time Division Multiple Access(TDMA) and data are transmitted over HBC capacitive coupling aside from a bio-signal sensing system. The transmitter time characteristics shows the feasibility of implementing a TDMA body sensors star network centralized into a single hub for a single connection to Wide Area Networks. The proposed system is composed by a bio-sensor unit and an HBC transmitter.