BPSK & QPSK modulated data communication for biomedical monitoring sensor network

Data communication between body-mounted sensors is progressing towards wireless monitoring networks. In this work, digital data communication by galvanic coupling through the body is presented as a promising approach for wireless intra-body communication. The human body itself serves as the transmission medium of electrical current. Both binary and quadrature phase-shift-keying (BPSK and QPSK) modulated data transmissions are implemented and compared for galvanic coupled links between 2 differential electrode pairs. The adaptive system offers up to 1 mA maximum current amplitude between 10 kHz and 1MHz. Data communication at a rate of up to 64 kbit/s was realized with BER of 10(-4) corresponding to an SNR greater than 6 dB. The novel technology has shown its feasibility in clinical trials. Furthermore, such a low-current approach enables data communication that is more energy-saving than other wireless technologies.