A Fuzzy Controller to Support FES-Based Sitting-Down in Paraplegia

Functional Electrical Stimulation is a rehabilitative technique aiming to induce controlled muscle contractions by means of small charge electrical pulses provided to the nerve suppling the targeted muscle. FES-based standing-up, standing and sitting-down exercises in some paraplegic patients are thought to help in preventing osteoporosis, improving movement at lower limb joints, improving digestion, respiration and urinary drainage, and much more helps the user in performing transfer motions as wheel chair-toilet, wheel chair-bed, and reaching various needed objects on shelves higher than their wheel-chair level. Any of these FES-based exercise phases has to be properly controlled in order to ensure a safe and comfortable movement. This paper presents a new fuzzy controller aiming to support sitting-down in paraplegia by controlling the quadriceps muscles and/or hamstrings muscles of the user by means of electrical stimulation. Its effectiveness has been tested in simulation, and compared with other clinically tested controllers when fed with real clinical tests data.