Stroke is the second highest cause of death worldwide and the third leading cause of adult disability across all age brackets. Recovering gait following stroke is a major goal of patients, and hence rehabilitation, as it is central to many activities of daily living. Of the different treatment modalities, robotic assisted gait training is growing in popularity, but is still considered complementary to, and not substitute for conventional therapies comprising physiotherapy, overground walking and body weight supported treadmill training. The potential advantages that lower limb robotics bring to neurorehabilitation over conventional therapies include, higher dosage, specificity, improved consistency, and duration, though these benefits have been slow to manifest. Exoskeletons are well placed to provide these benefits, as well as environmental variation and task salience if they can be used away from outpatient settings. Control strategies that may be enhancing of recovery are often confined to stationary exoskeletons, and the control of mobile exoskeletons is only loosely related to gait, if at all, which limits rehabilitation outcomes. -- The primary aim of this PhD thesis was to develop an adaptive, user-initiated gait Controller that aims to target a novel neural recovery pathway. The Controller would use a robotic exoskeleton, with the intention of developing novel neuroplasticity that is beneficial for gait and would be permissive of simultaneous control of hip and knee posture. A theoretical framework based on the principles of neuroplasticity was proposed that seeks to bring higher engagement, task variance, and volition to gait rehabilitation. This framework considers stroke and rehabilitation timelines and the interaction of the proposal with existing theory, how beneficial neuroplasticity may manifest, and how the proposal may be detrimental. A comprehensive survey of candidate lower limb devices followed (164 devices), to understand exactly what features are compatible, complementary, or contradictory to the proposed control method, and to understand the implications the various specifications have. Specifically, it was found that ambulating exoskeletons that can move around the environment were preferred for their ability to be used in the community and the home, and that extended joint range of motion will be permissive of activities that are supportive of gait such as sit-to-stand and stair ascent/descent. Of the various control systems that have been implemented with exoskeleton devices, trajectory control, where motion is enforced on the limb by the exoskeleton, is preferred. -- The method of control was assessed for suitability as a gait controller through a participant study (n = 21). Participants were asked to reproduce the motion required for the controller, and with minor modification to participant motion it was shown that reliable control signals can be obtained. The remainder of the thesis applies the learnings of the previous stages in the development of the Controller and an accompanying Sensor. The custom Sensor was designed with a small form factor to be applied on the Controller. The thesis concludes with an implementation of the Controller and a successful demonstration of the proposed concept, where the control signals are reproduced on a scale lower limb exoskeleton. The full technical detail and specification of the Controller, and the custom position Sensor developed specific for this application, are presented as part of this work. -- This work has added a new theoretical framework for gait control following stroke and has added technological capability to implement the proposal. It is the primary recommendation of this PhD that the novel control method be tested further with participant studies and that the component hardware be developed further. Therapies targeting novel recovery mechanisms breathe fresh air into rehabilitation and may inspire other new treatments, and future funded work originating from this PhD will see the concept tested with a chronic stroke population, using an ambulating exoskeleton and the Controller.

This conference proceeding gather a selection of peer-reviewed papers presented at the 1st International Conference on Artificial Intelligence for Smart Community (AISC 2020), held as a virtual conference on 17–18 December 2020, with the theme Re-imagining Artificial Intelligence (AI) for Smart Community to apply computational intelligence for biomedical instruments, automation & control, and smart community to develop suitable solution for various real-world application. The conference virtually brought together researchers, scientists, engineers, industrial professionals, and students presenting important results in the related field of healthcare technology, soft computing technologies, IoT, evolutionary computations, automation and control, smart manufacturing and smart cities. Researchers and scientist working in the allied domain of Artificial Intelligence and others will find the book useful as it will contain some latest computational intelligence methodologies and applications.

Several genetic, developmental and neurological disorders can cause various levels of gait impairment in the pediatric population. Powered lower limb orthoses, or exoskeletons, have recently been used to address gait impairment and afford therapists alternative solutions and strategies for gait therapy. Most exoskeleton research has focused on the adult population while the pediatric population remains underserved. The limitations of current pediatric exoskeletons make them impractical for use in both community and clinical settings. Furthermore, exoskeleton controllers suitable for these environments should promote human volitional control while guiding the subject towards a dynamically stable healthy gait pattern. This dissertation presents the design of a pediatric lower limb exoskeleton and the application of a virtual constraint-based controller on the device. First, a small and lightweight exoskeleton joint actuator capable of delivering the torque and power requirements needed to assist and guide the hip and knee joints was developed. Testing and in-air gait tracking of a model leg in a provisional orthosis demonstrated that the joint actuators were suitable for use in a pediatric exoskeleton. Second, an adjustable exoskeleton frame was designed and fabricated, and a human factors assessment of the fully assembled pediatric lower limb exoskeleton demonstrated that the device was lightweight, comfortable, easily adjustable and suitable for children. Third, a virtual constraint-based controller was applied on an underactuated adult exoskeleton. This initial investigation demonstrated that virtual constraint-based control guided the subject towards a dynamically stable gait in a time-invariant manner, provided greater volitional control to the subject and promoted active participation in the walking exercise. Finally, this dissertation research concluded with the application of a virtual constraint-based controller on the pediatric lower limb exoskeleton in treadmill walking experiments. The results showed that virtual constraint-based control reduced gait variability and the amount of robotic intervention applied relative to proportional-derivative control. Subject feedback also indicated that the virtual constraint-based controller was easier to use compared to time-based proportional-derivative control. This dissertation research demonstrates that the developed exoskeleton is suitable as an investigative platform for pediatric exoskeleton controllers and that virtual constraint-based controllers have potential for the rehabilitation and guidance of pediatric gait.

Robotic rehabilitation for physical therapy has several advantages over conventional manual rehabilitation, especially in the aspects of accuracy and repeatability. Initial attempts at robotic rehabilitation focused on training muscles by moving limbs in a fixed repetitive pattern. Later it was realized that such an approach could be suboptimal. Better approach would be the use of 'assist-as-needed' paradigm, where an orthotic device provides just enough assistance to enable the patient to move his leg under his own control. However, at this time, lower extremity devices which can apply appropriate forces to implement this paradigm are still in research and not commercially available. The goal of this work is to develop lower extremity orthotic devices using assist-as-needed paradigm for robotic rehabilitation. To achieve this goal two orthotic devices were developed. They are Gravity Balancing leg Orthosis (GBO) and Active Leg EXoskeleton (ALEX). GBO assists persons with hemiparesis to walk by reducing or eliminating the effects of gravity on the affected limb. The amount of assistance provided can be tuned by the therapist from 0% to 100% gravity balancing. For a quantitative evaluation of the performance of the device several experiments were conducted. These experiments were performed on five healthy subjects and three stroke patients. The results showed that with the GBO set to 100% balancing the EMG activity from the rectus femoris and hamstring muscles was reduced by 75%, during static hip and knee flexion, respectively. For leg-raising tasks the average torque for static positioning reduced by 66.8% at hip joint and 47.3% at knee joint, however if transient portion of the leg raising task is included, the average torque at hip reduced by 61.3% and at knee increased by 2.7% at knee joints. In the walking experiment there was a positive impact on the range of movement at the hip and knee joints, especially for stroke patients, the range of movement increased by more than 57% at hip joint and by more than 73% at the knee joint. These results show that the GBO provides assistance which can be used for rehabilitation. An intensive training of a stroke patient was performed to study the long term effects of GBO, the training lasting for six weeks. The training started out with maximum assistance of 100% gravity balancing and gradually reduced to 0% by the end of training. Patient is also shown visual display of his gait pattern in real time and summary performance after individual sessions. Some of the effects of the training were, increase in patients preferred speed of treadmill walking from 2.72 km/h to 3.04 km/h, patient's preferred overground speed increased from 3.38 km/h to 3.86 km/h by the last evaluation. An improvement of gait pattern was seen where the patients gait pattern became more like a healthy subject's pattern. The patient was able to increase weight bearing on the hemiparetic leg and was more symmetric in his walk. ALEX, on the other hand, is a motorized orthotic device. To achieve the goal of 'assist-as-needed' paradigm for ALEX, Force-Field controller was developed. This controller generates "virtual walls'' in the plane containing human thigh and shank segments. These virtual walls guide and assist the subject's foot along the prescribed trajectory. Linear actuators were used at hip and knee joints of the device. To make the actuators back-drivable, friction compensation was used. Gait training studies with healthy subjects were conducted to measure the effectiveness of ALEX in retraining modified gait pattern. The results show that a healthy human leg muscles can be trained in about 45 to 60 minutes to a modified pattern of foot trajectory. A 15-day long gait training was conducted with a stroke patient using ALEX, the results indicate that using ALEX and force-field controller, the patient's gait pattern improved significantly in many aspects. His gait speed improved both on treadmill from 1.45 km/h to 2.57 km/h and overground from 1.82 km/h to 2.50 km/h. His foot trajectory increased and got about 85% closer to a healthy subject's foot trajectory. Knee flexion increased from 27.2 deg to 47.5 deg and ankle dorsi-flexion increased from 1.9 deg to 5.9 deg by the end of the training. All these results indicate that by using these devices suitably and implementing a long term gait training can help patients with walking disability in a speedy recovery.

The book provides readers with a comprehensive overview of the state of the art in the field of gait and balance rehabilitation. It describes technologies and devices together with the requirements and factors to be considered during their application in clinical settings. The book covers physiological and pathophysiological basis of locomotion and posture control, describes integrated approaches for the treatment of neurological diseases and spinal cord injury, as well as important principles for designing appropriate clinical studies. It presents computer and robotic technologies currently used in rehabilitation, such as exoskeleton devices, functional electrical stimulation, virtual reality and many more, highlighting the main advantages and challenges both from the clinical and engineering perspective. Written in an easy-to-understand style, the book is intended for people with different background and expertise, including medical and engineering students, clinicians and physiotherapists, as well as technical developers of rehabilitation systems and their corresponding human-compute interfaces. It aims at fostering an increased awareness of available technologies for balance and gait rehabilitation, as well as a better communication and collaboration between their users and developers.

This book reports on the latest advances in concepts and further development of principal component analysis (PCA), discussing in detail a number of open problems related to dimensional reduction techniques and their extensions. It brings together research findings, previously scattered throughout many scientific journal papers worldwide, and presents them in a methodologically unified form. Offering vital insights into the subject matter in self-contained chapters that balance the theory and concrete applications, and focusing on open problems, it is essential reading for all researchers and practitioners with an interest in PCA

Stroke is one of the leading cause of physical disability in New Zealand and many suffer paralysis to their limbs. Unfortunately, fewer than 50% of survivors regaining their independence after 6 months particularly due to the inability to walk properly. One of the reason for the slow recovery of the gait function is that the current rehabilitation technique used is labour intensive and time consuming for the therapists and difficult to perform it effectively. In order to improve the gait rehabilitation process, robot assisted gait rehabilitation has gained much interest over the past years. There have been many prototypes and commercial products for the robot assisted rehabilitation, but many had limitations. One of which is being bulky and had uncomfortable attachment for the patients. Improper attachment not only create uncomfortable feeling and pain for the patient but also causes human-robot axis misalignment which could lead to an injury with long term use. Another limitation is the lack of mechanical compliance which is the key to improve the safety of the operation and comfort for the patient. In order to address the limitations identified, a new robot orthosis, Human-inspired Robotic Exoskeleton (HuREx) was developed. HuREx consists of a compact exoskeleton parts custom fit for each individual patient manufactured using a rapid prototyping technique. Pneumatic Muscle Actuators (PMA) were used as they exhibit natural compliance and configured antagonistically. The design of the orthosis and the actuation mechanism made the system highly nonlinear. Therefore, an advanced model-based feedforward (FF) controller was designed and implemented to achieve the speed and accuracy of the response required. Many experiments were carried out to observe the performance and verify the proof of concept. The contributions of this research are the development of new robotic exoskeleton device designed to be light weight, comfortable and safe to use for gait rehabilitation for stroke patients, which were lacking in the existing devices. Another contribution is the establishment of new manufacturing technique that allow custom exoskeleton component for each individual patient. Finally the development of advanced model-based FF controller that achieves fast and accurate tracking performance.

This book addresses cutting-edge topics in robotics and related technologies for rehabilitation, covering basic concepts and providing the reader with the information they need to solve various practical problems. Intended as a reference guide to the application of robotics in rehabilitation, it covers e.g. musculoskeletal modelling, gait analysis, biomechanics, robotics modelling and simulation, sensors, wearable devices, and the Internet of Medical Things.