In order to control the proposed motorized exoskeleton glove, an Electromyography (EMG) and Forcemyography (FMG) based wearable sleeve system was developed (see Fig.1). The sleeve interface is equipped with 3 bipolar EMG channels and 5 FMG sensors. It is made out of a breathable and stretchable fabric and can be easily worn using a zipper. The FMG sensors are implemented using Force Sensitive Resistors (FSR) and silicone based supporting pads, while the EMG sensors are developed using reusable wet silver electrodes supported by thick silicon blocks to maintain a tight contact with the human skin. The EMG electronics include four stages: i) the differential amplification, ii) band-pass filtering, iii) full-wave rectification and iv) calculation of the envelope of the signal. 

The FSR sensors are the 402-Round sensors (Interlink Electronics, Camarillo, CA, USA) and have a force sensitivity range of 0.2N-20N which is enough to detect even the slightest muscle movements. The reusable electrodes are manufactured by printing conductive silver ink on poly-ethylene terephthalate (PET) sheets using an inkjet printer. The advantage of using these electrodes over commonly used gel electrodes is that they do not need to be discarded after every use and can be developed in any shape and size to suit the requirements of the application and to improve the efficiency of the system.

Fig. 2 shows the placement of the FMG and EMG sensors on the human forearm when the sleeve is worn. The sensors E1 and F1 are placed on the extensor digitorum superficialis muscle site to capture the finger extensions, sensor F2 is placed on extensor pollicis brevis muscle to capture the thumb extensions, sensor E2, E3, F3 and F4 were placed on the flexor digitorum superficialis muscle site to capture finger flexion and sensor F5 was placed on flexor digitorum profundus muscle site to capture the flexion of the distal joints when a fist is made.

The video below demonstrates the operation of the wearable sleeve system: