1 Preliminary Study of Functional Electrical Stimulation: Application of swinging trajectory based on Knee-Joint range-of-motion (ROM) M.K.I.Ahmad 1 1 Department of Mechatronic and Robotic Engineering, 3 Modeling and Simulation Research Laboratory, Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, MALAYSIA mohdkhairulikhwan@gmail.com B.S.K.K .Ibrahim 1,3 , A.U.Shamsudin 1 , D. Hanafi 1 , M. Mahadi Abdul Jamil 2,3 , N.H.M.Nasir 1,3 , F. Sherwani 1,3 , K.A.A.Rahman 1,3 , A.Masdar 2,3 1 Department of Mechatronic and Robotic Engineering, 2 Department of Electronic Engineering, 3 Modeling and Simulation Research Laboratory, Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, MALAYSIA he130106@siswa.uthm.edu.my Abstract— Nowadays, research and developments of control system for spinal cord injury (SCI) using functional electrical stimulation (FES ) is widely used. Restoring mobility to persons with paraplegia with regard to FES -approaches for function restoration is really challenging issues. A sarcastic view of FES is the complexity control of muscle motor function by the arti- ficial activation of paralyzed muscles. Therefore; laboratory apparatus setup to study the knee joint control by FES electri- cal stimulation test with computer-controlled stimulator sys- tem consisted of Matlab/Simulink-Hasomed has been ar- ranged. Anthropometric measurements of length of the lower limb were made. Novel wearable lower limb suit developed for FES experimental. This scenario can be seen by monitoring the sinusoidal stimulation current range muscle contraction on able-bodied (AB) subject with the simulation work was applied on knee joint swinging trajectory range-of-motion. Significant value of sinusoidal stimulation current signal is determined and regulated to vary within potential of preliminary data mining attempts to model an efficient power consume of knee joint controller. At this stage, it can improve with better tech- nique by reduce and determine overall parameter limitation using FES. Index Terms — Functional Electrical Stimulation (FES), Spinal Cord Injury (SCI), free-swinging, rehabilitation, wear- able lower limb suit, electrical stimulation test. I. INTRODUCTION Currently, research and development in rehabilitation engineering by using functional electrical stimulation (FES) has been increased in recent year [5, 6, 14]. Since 1960’s, as illustrated in Figure 1, FES has been explored for activation muscles [5, 11] such as means of restoring lost function of in the spinal cord injury (SCI) person with paralysis [1, 3, 5, 7, 8, 10, 16, 35] in type of electrical stimulation trains by different combinations of frequency and pulse-width [12, 13, 17]. Fig. 1. Timeline history of FES applications Nowadays, electrical stimulation can be applied via sur- face, intramuscular or implanted electrodes which can pro- duce artificial contraction of paralyzed muscles provided that fibre depolarization is already achieved [1]. In fact, FES is a treatment that uses the application of small electri- cal current signal in order to improve mobility [2, 5, 6, 8] due to SCI, to facilitate patient-responsive ambulation, brachial plexus injury, stroke, rapid muscle wastes of the thigh, multiple sclerosis, and traumatic brain injury [5, 9, 18, 19, 27, 28]. The application of FES as a therapeutic and rehabilitation modality includes muscle strengthening and cardiovascular reconditioning, endurance, improving range- of-motion (ROM), standing and gait control, enhancement of limb function, facilitation of voluntary responses, relaxa- tion of spastic muscles, wound healing, improve blood flow, improve sensory awareness, reduce pain associated with spasticity, reduction of osteoporosis, and orthotic substitu- tion [20-22, 29, 38]. There are also additional benefits to 978-1-4799-6483-3/14/$31.00 ©2014 IEEE