Robot Assisted Shoulder Rehabilitation: Biomechanical Modelling, Design and Performance Evaluation

The upper limb rehabilitation robots have made it possible to improve the motor recovery in stroke survivors while reducing the burden on physical therapists. Compared to manual arm training, robot-supported training can be more intensive, of longer duration, repetitive and task-oriented. To be aligned with the most biomechanically complex joint of human body, the shoulder, specific considerations have to be made in the design of robotic shoulder exoskeletons. It is important to assist all shoulder degrees-of-freedom (DOFs) when implementing robotic exoskeletons for rehabilitation purposes to increase the range of motion (ROM) and avoid any joint axes misalignments between the robot and human’s shoulder that cause undesirable interaction forces and discomfort to the user. The main objective of this work is to design a safe and a robotic exoskeleton for shoulder rehabilitation with physiologically correct movements, lightweight modules, self-alignment characteristics and large workspace. To achieve this goal a comprehensive review of the existing shoulder rehabilitation exoskeletons is conducted first to outline their main advantages and disadvantages, drawbacks and limitations. The research has then focused on biomechanics of the human shoulder which is studied in detail using robotic analysis techniques, i.e. the human shoulder is modelled as a mechanism. The coupled constrained structure of the robotic exoskeleton connected to a human shoulder is considered as a hybrid human-robot mechanism to solve the problem of joint axes misalignments. Finally, a real-scale prototype of the robotic shoulder rehabilitation exoskeleton was built to test its operation and its ability for shoulder rehabilitation

Utilizing the intelligence edge framework for robotic upper limb rehabilitation in home

Robotic devices are gaining popularity for the physical rehabilitation of stroke survivors. Transition of these robotic systems from research labs to the clinical setting has been successful, however, providing robot-assisted rehabilitation in home settings remains to be achieved. In addition to ensure safety to the users, other important issues that need to be addressed are the real time monitoring of the installed instruments, remote supervision by a therapist, optimal data transmission and processing. The goal of this paper is to advance the current state of robot-assisted in-home rehabilitation. A state-of-the-art approach to implement a novel paradigm for home-based training of stroke survivors in the context of an upper limb rehabilitation robot system is presented in this paper. First, a cost effective and easy-to-wear upper limb robotic orthosis for home settings is introduced. Then, a framework of the internet of robotics things (IoRT) is discussed together with its implementation. Experimental results are included from a proof-of-concept study demonstrating that the means of absolute errors in predicting wrist, elbow and shoulder angles are 0.89180,2.67530 and 8.02580, respectively. These experimental results demonstrate the feasibility of a safe home-based training paradigm for stroke survivors. The proposed framework will help overcome the technological barriers, being relevant for IT experts in health-related domains and pave the way to setting up a telerehabilitation system increasing implementation of home-based robotic rehabilitation. The proposed novel framework includes: • A low-cost and easy to wear upper limb robotic orthosis which is suitable for use at home. • A paradigm of IoRT which is used in conjunction with the robotic orthosis for home-based rehabilitation. • A machine learning-based protocol which combines and analyse the data from robot sensors for efficient and quick decision making

Modelling of the human shoulder girdle as a 6-4 parallel mechanism with a moving scapulothoracic joint

Human shoulder movements involve motions at four different articulations, one of which is the contact between the scapula bone and the ribcage. The shoulder biomechanical models become less reliable when the scapulothoracic (ST) contact, which is not a joint in the anatomical sense, is not considered. On the other hand, constraints posed by the ST contact reduce the number of degrees of freedom (DOF) and introduce the interdependencies between the joint coordinates which in turn complicates the motion planning. However, a minimal parameterization that incorporates the constraints, notably simplifies costly computational procedure related to the model predictions. In this paper, the complex kinematics of the human shoulder is analyzed considering the point-contact model between scapula bone and thorax. Later, replacing the contact constraint with an equivalent kinematic chain and adding parallel kinematic links, the human shoulder girdle is modelled as a 6-4 parallel mechanism. A novel minimal set of independent parameters equal to the number of degrees of freedom is then devised in terms of the parallel mechanism\u27s link lengths and the shoulder joint angles. The proposed parallel mechanism can also emulate the moving ST contact point during the shoulder motions. Finally, the shoulder motion planning method in terms of the time-dependent minimal coordinates is presented

A hybrid multi-joint robotic shoulder exoskeleton for stroke rehabilitation

The appropriate functionality of the human shoulder including the shoulder girdle movements is crucial for effective use of the arm during activities of daily living (ADL). It is important to assist all shoulder degrees-of-freedom (DOFs) when implementing robotic exoskeletons for rehabilitation purposes to increase the range of motion (ROM) and avoid any joint axes misalignments between the robot and human\u27s shoulder that cause discomfort to the user. In this paper, a new lightweight shoulder exoskeleton is proposed, which can provide anatomically accurate shoulder movements to the neurologically impaired subjects by assisting all of the human shoulder DOFs and can minimize any effect of joint axes misalignments. The description and operation of this hybrid multi-joint ergonomic mechanism is presented in detail. Its kinematics, preliminary workspace analysis and mechanical interference issues are examined using CAD software tools. The discussion and future work on the proposed robotic shoulder exoskeleton are given to indicate its benefits of larger workspace, intrinsic compliance and increased functionality

Review on Design and Control Aspects of Robotic Shoulder Rehabilitation Orthoses

Robotic rehabilitation devices are more frequently used for the physical therapy of people with upper limb weakness, which is the most common type of stroke-induced disability. Rehabilitation robots can provide customized, prolonged, intensive, and repetitive training sessions for patients with neurological impairments. In most cases, the robotic exoskeletons have to be aligned with the human joints and provide natural arm movements. This is a challenging task to achieve for one of the most biomechanically complex joints of human body, i.e., the shoulder. Therefore, specific considerations have been made in the development of various existing robotic shoulder rehabilitation orthoses. Different types of actuation, degrees of freedom (DOFs), and control strategies have been utilized for the development of these shoulder rehabilitation orthoses. This paper presents a comprehensive review of these shoulder rehabilitation orthoses. Recent advancements in the mechanism design, their advantages and disadvantages, overview of hardware, actuation system, and power transmission are discussed in detail with the emphasis on the assisted DOFs for shoulder motion. A brief overview of control techniques and clinical studies conducted with the developed robotic shoulder orthoses is also presented. Finally, current challenges and directions of future development for robotic shoulder rehabilitation orthoses are provided at the end of this paper