Several technological solutions have ben recently proposed for fingers rehabilitation in patients who were affected by a stroke, in particular for those who cannot generate the finger force but with preserved sEMG signals. In fact, a very promising approach uses a robot rehabilitation system controlled through sEMG signals. However, this system has two main problems: 1) the placement of electrodes is made manually and this could bring to a non-optimal detection of signals; 2) the cost of treatments is very high, mainly due to the usage of single-use, dispodsable electrodes. Our proposal is to use a robot rehabilitation system with a low-cost armband instead of standard electrodes. The armband has 8 sEMG sensors and a 9-DoF inertial sensor, it has electrically safe setup with low voltage battery and Bluetooth protocol. Moreover it is a very low cost and reusable equipment. The validity of the proposal was confirmed through experiments.