Babul Salam Ksm Kader Ibrahim

Fundamental study on brain signal for BCI-FES system development

Electroencephalographic measurements are commonly used in medical and research areas. This article presents an introduction into Electroencephalography (EEG) measurement and the simple experiment of EEG. Its purpose is to develop orientation in EEG field and with building basic knowledge for performing EEG recordings. The normal person used as subject was used in this experiment. It is conducted in three condition; relax, hand grasp and lastly grasp and release. At the end of the experiment, there are some changes of the brain signal due to the activity that subject has been done. It shows that the brain will generate the different signal relate to the activity or the way of thinking of the subject. This study will be used as a fundamental concept for Brain Computer Interface (BCI)-Functional Electrical Stimulation (FES) system development.

Fuzzy logic based cycle-to-cycle control of FES-induced swinging motion

FES induced movement control is a significantly challenging area due to complexity and non-linearity of musculo-skeletal system. The goal of this study is to design a cycle-to-cycle control of FES-induced swinging motion. In this approach only the quadriceps muscle is stimulated by controlling the amount of stimulation pulsewidth. This time dependent behaviour is successfully compensated for using a cycle-to cycle fuzzy controller, which computes the amount of knee extension stimulation on the basis of the achieved flexion angle in previous cycles. The capability of fuzzy control in automatic generation of stimulation burst duration is assessed in computer simulations using a musculo-skeletal model. This paper presents the development of a fuzzy logic control scheme based on discrete-time cycle to cycle control strategies without predefined trajectory. The results show the effectiveness of the approach in controlling FES-induced swinging motion

Development of wireless-based low-cost current controlled stimulator for patients with spinal cord injuries

A spinal cord injury (SCI) has a severe impact on human life in general as well as on the physical status and condition. The use of electrical signals to restore the function of paralyzed muscles is called functional electrical stimulation (FES). FES is a promising way to restore mobility to SCI by applying low-level electrical current to the paralyzed muscles so as to enhance that persons ability to function and live independently. However, due to the limited number of commercially available FES assisted exerciser systems and their rather high cost, the conventional devices are unaffordable for most peoples. It also inconvenient because of wired based system that creates a limitation in performing exercise. Thus, this project is concerned with the development of low-cost current controlled stimulator mainly for the paraplegic subjects. The developed device should be based on a microcontroller, wireless based system using Zigbee module, voltage-to-current converter circuit and should produce proper monophasic and biphasic current pulses, pulse trains, arbitrary current waveforms, and a trigger output for FES applications. The performances of the device will be assessed through simulation study and validated through experimental work. This device will be developed as in the new technique of the stimulator development with low cost and one of the contributing factors in Rehabilitation Engineering for patients with SCI.

Development of fuzzy muscle contraction and activation model using multi-objective optimisation

Characterization of electrically stimulated muscle is complex because of the non-linearity and time-varying nature of the system with interdependent variables. The muscle model consists of relatively well known time-invariant passive properties and uncertain time-variant active properties. The objective of this study is to develop an active properties model that can be implemented in biomechanical models of the lower extremities, which are generally used for the simulation of joint movements such as walking and cycling, A new approach for dynamic characterization of active properties (combination of muscle contraction and activation) of the quadriceps muscle using fuzzy model by optimizing with multi objective genetic algorithm (MOGA) is presented. MOGA is used with two objectives; to minimize the prediction error to fit the experimental data and reduce the weighting factors of the fuzzy rules to minimize the complexity of the fuzzy model. The results show that the knee joint model developed gives an accurate dynamic characterization of active properties of the knee joint.

PI-Fuzzy Logic Control for 3 Phase BLDC Motor for Electric Vehicle Application

Brushless DC motor has been widely used in electric vehicle because of its high performance and simplicity. However this motor is a multi-variable, non-linear system and easily can be influenced by the parameter variations and disturbances. The conventional controllers are unable to handle this problem. To overcome this problem a nonlinear PI-fuzzy logic controller is used to control the speed of electric vehicle traction motor. The development of this control strategy is presented in this paper. The proposed controller has simple structure and also due to its modest fuzzy rule in rulebase is relatively easy for implementation. The control is performed by Matlab/Simulink software. The simulation test results have been satisfactory in both steady and transient states. This controller has high accuracy, suitable performance, high robustness and high tracking efficiency.

Fuzzy modelling of knee joint with genetic optimization

Modelling of joint properties of lower limbs in people with spinal cord injury is significantly challenging for researchers due to the complexity of the system. The objective of this study is to develop a knee joint model capable of relating electrical parameters to dynamic joint torque as well as knee angle for functional electrical stimulation application. The joint model consists of a segmental dynamic, time-invariant passive properties and uncertain time-variant active properties. The knee joint model structure comprising optimised equations of motion and fuzzy models to represent the passive viscoelasticity and active muscle properties is formulated. The model thus formulated is optimised using genetic optimization, and validated against experimental data. The developed model can be used for simulation of joint movements as well as for control development. The results show that the model developed gives an accurate dynamic characterisation of the knee joint.

Current source with low voltage controlled for surface Electrical Stimulation

Functional Electrical Stimulation (FES) is a promising way to restore mobility to Spinal Cord Injury (SCI) patients by applying low-level electrical current to the paralyzed muscles so as to enhance that persons ability to function and live independently. However, due to the limited number of commercially available FES assisted exerciser systems and their rather high cost, the conventional devices are unaffordable for most peoples. Thus, this paper makes a comparative study of the various design of a multiple purpose portable functional electrical stimulator which is used in surface stimulation for patients with spinal cord injuries. The functionality, circuit performance and reliability of the circuits are presented.

Natural trajectory based FES-induced swinging motion control

The use of electrical signals to restore the function of paralyzed muscles is called functional electrical stimulation (FES). FES is a promising method to restore mobility to individuals paralyzed due to spinal cord injury. FES induced movement control is a significantly challenging area, mainly emanating from various characteristics of the underlying physiological/biomechanical system. An approach of fuzzy trajectory tracking control of swinging motion optimized with genetic algorithm is presented. The results show the effectiveness of the approach in controlling FES-induced swinging motion. In this approach only the quadriceps muscle is stimulated to perform the swinging motion by controlling the amount of stimulation pulsewidth

Review and Development of Tetraplegic-Musculoskeletal FES-Elbow Joint Extension Control Strategies

The application of FES as a therapeutic and rehabilitation functionality is globally used especially for paralyzed person induced by SCI. The potential of this research is FES induced movement control on a significantly challenging area due to complexity and non-linearity of tetraplegic musculoskeletal system. The challenge mainly arises within FES application based on a crucial issue, in the control of musculoskeletal upper limb motor function by the artificial activation of paralyzed muscles, due to the various characteristics and parameters of the underlying physiological/biomechanical system. This research pilot study attempts to propose model theoretical framework/control strategies with computer validation simulations studies.

Knee joint impedance hybrid modeling and control of functional electrical stimulation (FES)-cyclingfor paraplegic: Free swinging trajectory

Functional electrical stimulation (FES) has been used to restore the function of paralyzed muscles due to spinal cord injury (SCI). FES induced movement control is a significantly challenging area due to complexity and nonlinearity of musculoskeletal system. A crucial issue of FES is the control of motor function by the artificial activation of paralyzed muscles due to the various characteristics of the underlying physiological/biomechanical system. Muscle response characteristics are nonlinear and time-varying with fatigue issues. In this approach only the quadriceps muscle is stimulated to perform the trajectory motion. This paper presents the initial development of control strategies using FLC and GA in order to optimize the system by FES-cycling trajectory control via Analog Digital Converter, ADC.