The Encyclopedia of Medical Robotics

The following sections are included:

• PREFACE
• ABOUT THE EDITOR
• CONTENTS

Robotic rehabilitation devices have become increasingly important and popular in clinical and rehabilitation environments to facilitate prolonged duration of training, increased number of repetition of movements, improved patient safety, less strenuous operations by therapists, and eventually to improve the therapeutic outcome. After presenting the rationale of robot-aided movement therapy, this article shows several design criteria that are relevant for the development of effective and safe rehabilitation robots. Several examples of gait rehabilitation robots are then presented that are in the developmental status or already commercially available. Novel patient-cooperative strategies are described, such as impedance control, assistance-as-needed control and tunnel (path) control. Such patient-cooperative strategies can increase movement variability, patient activity, and patient motivation; all of this can have a positive effect on the therapeutic outcome. This chapter finishes with a short overview about existing clinical trials that have been performed showing that the application of rehabilitation devices is at least as effective as the application of conventional therapies. It concludes with the finding that further clinical studies are required to find predictors for the success of a robot-aided treatment.

In recent years, robotic technology has been suggested in walking rehabilitation to replace traditional manual-assisted training. However, the effectiveness of the robot-assisted walking training does not show clear superiority to manually-assisted training. One of the possible reasons may be due to the limited balance training activities provided in the current walking rehabilitation robots. On the other hand, high falling rate is observed in both stroke patients and elderly persons, which demonstrates the importance of walking postural balance training. In this chapter, a review of walking postural balance training is therefore devoted to investigate the current advancements, limitations and discuss about possible solutions. Firstly, the mechanism of walking postural balance control is studied through three aspects: proactive (or anticipatory)walking postural balance control, reactive walking postural balance control, and balance state feedback. Next, a review of the existing robotic technology for the walking rehabilitation is presented by focusing on the aspect of postural balance training. Finally, the chapter discusses possible ways to improve balance training activities during robot-assisted walking training through robotic hardware and control algorithm. In conclusion, balance-training activities are essential in a rehabilitation program. More and more rehabilitation systems are shifting their attention toward postural balance-training capabilities. Nevertheless, it is still unclear which are the optimal approaches to enhance the balance-training properties. Rigorous clinical evidences are needed to support these new approaches. We are optimistic that with careful research and consideration on the principle of human postural balance and its application to robot design and control, the efficiency of robot-assisted rehabilitation walking training can be improved.

In an era where the aging of population and the increased incidence of gait impairments are dominant trends, the need for devices capable of enabling a proper sustenance of the global welfare and healthcare costs is increasing. Sophisticated lower limb wearable robots have been developed over the years in order to prevent and provide a reliable solution to major social and economical issues for people affected by gait disorders. Nevertheless, their acceptability and usability are still limited by several unresolved challenges in terms of physical and cognitive human-robot interactions. The goal of this chapter is to provide an example of the design of the mechatronic architecture of a wearable active pelvis orthosis (APO) for assisting hip flexion-extension movements during activities of daily living (ADL). The device safely complies with the human biomechanics and is adaptive in its mechanical structure and in its control policy to different anthropometries and inter-/intrasubject walking patterns. Starting from a laboratory prototype with off-board control and power supply units to a totally portable version, the design of the active pelvis orthosis followed and advanced the recent trends of the wearable robot development. We expect that in the coming years, people affected by lower limb impairments could take advantage of wearable robots like the APO and experience a reduction in the physical burden of locomotion-related activities, thus increasing their socio-economical engagement and quality of life.

Robotic lower limb prostheses can actively regulate joint torque to restore more natural and efficient ambulation for individuals with leg amputation. Motorized prosthetic joints generate significant amounts of energy, thus allowing amputees to perform activities with active dynamics, such as reciprocal stair climbing and sit-to-stand transitions, that are not possible with conventional passive prostheses. However, to restore physiological ambulation ability with a robotic prosthesis, prosthetic joint movements must be synchronized with the user’s movements. This requires the control system to detect the intended ambulation activity and seamlessly adjust the prosthesis movement accordingly. This chapter discusses the challenges in the control of robotic lower limb prostheses, specifically focusing on the most recent approaches to adapting robotic prosthesis movement to the user’s intended movement. Examples from our results with a robotic ankle and knee prosthesis will be used to illustrate the potential benefits of using a robotic prosthesis over a conventional passive device. Current limitations and barriers to translating robotic prostheses into clinically viable devices will also be discussed.

Great strides have been made over the last two decades to develop powered, active, ankle–foot orthoses and prostheses. Lightweight, powerful systems return gait movements and torques (kinematics and kinetics) to the user. An explosion of research in the areas of biomechanics, control, and mechanical design has allowed systems to assist and enhance the user’s ambulatory pattern. This review will discuss the trends in the development of wearable robotic systems enhancing ankle gait. Trends in passive systems include the development of lightweight carbon fiber systems for drop foot. Trends in active systems include the development of lightweight, battery-powered, motorized ankle–foot orthoses to aid in rehabilitation of stroke survivors. Similar systems are being built to assist transtibial and transfemoral amputees. Many new systems are quasi-passive and use minimal control techniques to tune the device during the gait cycle. Lastly, there has been a trend to develop soft-actuation techniques that do not rely on rigid exoskeletal structures. The trend is for smarter, more lightweight, powerful systems that return better gait kinematics and kinetics reducing metabolic cost.

The human hand plays an important role in the manipulation and exploration of the environment. Unfortunately, when disease or injury impedes hand function, the consequences are numerous including disrupting quality of life, independence, and financial stability. In this chapter, we present the development of a soft robotic glove designed to support basic hand function. The glove uses soft fluidic actuators programmed to apply assistive forces to support the range of motion of a human hand. More specifically, we present a method of fabrication and characterization of these soft actuators as well as consider an approach for controlling the glove. This analysis concludes with results from preliminary human subjects testing where glove performance was evaluated on a healthy and an impaired subject.

Since the wearable system is intended to be worn and manipulated by humans, the system provides intuitive motions that supplement and enhance the limited, insufficient, lost or absent human physical functions. With more advances in autonomous robotic technology, the wearable system has been well applied in the rehabilitation area, and it is about to open a new era where many disabled people can function as able ones. Several wearable systems are presented in this chapter. The types of the system include upper body wearable system, lower limb wearable system, ankle rehabilitation system, treadmill gait training system, physical assistive system and soft robotic system. The purpose of this chapter is to present the state-of-the-art wearable systems of rehabilitation, so as to provide a potentiality that the readers can utilize this knowledge and may even apply it for further development.

The Smart Health paradigm has opened up immense possibilities for designing modern cyber–physical/robotic systems for implementing data-, information- and knowledge-driven execution of healthcare decision making processes.

Children with cerebral palsy (CP) often suffer from movement disorders. They show poor balance and motor coordination. These children typically use passive walkers in their early years. However, there are no prior studies that document the effects of robot-enhanced walkers on functional improvements of these children. This paper reports the results of two pilot studies where children were trained to walk with a robot to perform a series of tasks with increasing levels of difficulty over a number of training sessions. The outcome measures are based on both data collected by the robot such as travel distance, average speed, and success ratio of given task and clinical variables to characterize their levels of disability and motor function. This pilot study documents the training outcomes for children with CP and compares results (i) between small and large number of training sessions and (ii) between toddlers and older children.

From autism spectrum disorder (ASD) to cerebral palsy (CP), there are many compelling reasons for utilizing robots in therapy and rehabilitation scenarios for children. These capabilities range from engaging children with pervasive development disorders to robot-assisted gait training for improving functional capabilities of children with motor impairments. Although there are some promising results found in the field, there are still a number of open-ended difficulties to resolve, especially in providing sufficient evidence of the long-term benefits of pediatric robots. In this chapter, we discuss the various robotic platforms that have been developed, challenges associated with their adoption, and outlooks for the future.

The following section is included:

• INDEX