The paper presents the design and characterization of a wearable instrument which measures simultaneously the electrodermal activity and the heart rate variability. The device measures the electrocardiogram on three channels and the skin potential response (endosomatic electrodermal activity) with a sample rate 1 kSa/s, 12 bits resolution. The bandwidth of ECG channels is [0.025, 160] Hz and the bandwidth of electrodermal channel is [0.08, 40] Hz. Data are transmitted via Bluetooth to a developed graphical user interface, which can run on a laptop or smartphone/tablet. The system is a useful tool to assess the sympathetic activity on heart rate variability.
