Assistive and rehabilitation systems have attracted extensive interest in recent years because of their potential benefits of enhancing motor function in patients with motor dysfunction. Neuromuscular disorders, such as muscle atrophy, spinal cord injury, or stroke, can severely disrupt the motor ability of patients.
Functional electrical stimulation (FES) and robotic exoskeletons are two major technologies used in rehabilitation and assistive devices. FES is a technique that uses low-energy electrical pulses to artificially generate body movements in individuals who have been paralyzed due to injury to the central nervous system. More specifically, FES can be used to generate muscle contraction in otherwise paralyzed limbs to produce functions such as grasping, walking, and standing. It can provide not only functional movement but also therapeutic benefits to patients with neurological injuries, including injuries in the central nervous system. Robotic exoskeletons are complex electromechanical systems that mimic the exoskeletons of some creatures seen in nature. They can both support and augment human performance by increasing strength, endurance, and other physical capabilities. An exoskeleton may be either active or passive. An active (or assistive) exoskeleton is powered by electric motors, pneumatic artificial muscles, or other kinds of powered actuators. Passive exoskeletons do not include actuators but counter the effects of gravity using passive components such as springs or dampers.
FES and exoskeleton have its own advantages and disadvantages, respectively. Exoskeletons can not only augment the capability of human limbs but also treat disorders of the muscles, joints, or the skeleton. They can also support the arm and compensate for its weight. Exoskeletons offer advantages in their ability to provide assistance or resistance repetitively. However, portability is often limited because the actuators of active exoskeletons tend to be heavy and have high power requirements. Comparatively, FES can provide therapeutic benefits to patients with neurological injuries as well as generate functional movements. Advantages of FES can include wearability, portability, acceptance, and usability. While FES is prone to causing muscle fatigue and may not generate enough torque for the desired motion.
A hybrid system combining functional electrical stimulation and robotic exoskeletons for upper-limb rehabilitation training is proposed in this project. The project targets stroke patients who are expected to perform versatile rehabilitation motion tasks with the assistance of the proposed system with 7 degrees of freedoms. FES and exoskeleton complement each other in this system. Multiple muscles may be actively excited via FES in a synergetic pattern, and simultaneously exoskeleton can assist a patient’s impaired limb to accomplish a full rehabilitation task. The inherent shortcomings of FES and exoskeleton can be overcome in such a hybrid system.
This research project will be carried out as part of an interdisciplinary integrated PhD in the Centre for Autonomous Robotics (CENTAUR), University of Bath.
Start date: 4 October 2022.
Competitive PhD scholarships are available.
Candidates are expected to have bachelor’s degree in good universities, or near complete an MSc or MEng in Mechatronics, Mechanical Engineering, Robotics, Electrical Engineering, Control Engineering, Biomedical Engineering, or related areas.
Informal enquiries about the project should be directed to Dr Dingguo Zhang.
Email: [email protected]
Formal applications should be made via the Department of Electronic and Electrical Engineering at University of Bath’s online application form and should include a research proposal. The application process is available here.