Based on the system architecture illustrated in Figure 1 we have developed a prototype of a WBAN of devices for physiological signal measurement, represented in Figure 2. The ECG signals were acquired by using a 3-lead custom developed ECG amplifier. The amplifier has for each channel a high gain (500), a high input impedance (>10MΩ) and common mode rejection (>90dB), a cut-off frequency around 35Hz and is AC coupled.