Vision System-Based Design and Assessment of a Novel Shoulder Joint Mechanism for an Enhanced Workspace Upper Limb Exoskeleton

Abstract

Exoskeletons arise as the common ground between robotics and biomechanics, where rehabilitation is the main field in which these two disciplines find cohesion. One of the most relevant challenges in upper limb exoskeleton design relies in the high complexity of the human shoulder, where current devices implement elaborate systems only to emulate the drifting center of rotation of the shoulder joint. This paper proposes the use of 3D scanning vision technologies to ease the design process and its implementation on a variety of subjects, while a motion tracking system based on vision technologies is applied to assess the exoskeleton reachable workspace compared with an asymptomatic subject. Furthermore, the anatomic fitting index is proposed, which compares the anatomic workspace of the user with the exoskeleton workspace and provides insight into its features. This work proposes an exoskeleton architecture that considers the clavicle motion over the coronal plane whose workspace is determined by substituting the direct kinematics model with the dimensional parameters of the user. Simulations and numerical examples are used to validate the analytical results and to conciliate the experimental results provided by the vision tracking system.

A review: A Comprehensive Review of Soft and Rigid Wearable Rehabilitation and Assistive Devices with a Focus on the Shoulder Joint

“…Exoskeletons are based on the architecture of industrial robots and include actuators, mechanisms and similar materials. They also include the lower and upper limbs, which act directly on the human body [76], however, this paper investigated only the upper limbs. Despite the existing complexities, many upper exoskeletons of rehabilitation have been developed and tested in the last two decades [70].…”

Kinematic of the Position and Orientation Synchronization of the Posture of a n DoF Upper-Limb Exoskeleton with a Virtual Object in an Immersive Virtual Reality Environment

“…This paper will use a 5 DoF upper-limb exoskeleton that has been previously proposed in the literature [6] to demonstrate the concept of position and orientation synchronization. This section presents a description of the upper-limb exoskeleton and its kinematics analysis.…”

“…The recent technological advances that emerged in the last decade, including digital manufacturing and rapid prototyping, have boosted the development of these devices. Exoskeleton design requires careful attention to provide natural motion of the users without endangering their safety [4,5], which can be achieved by the application of biomimetic design methods [6].…”

“…The main objective of the paper is to present the kinematic analysis of pose synchronization between an n DoF upper-limb exoskeleton, and an immersive virtual object projected by virtual reality glasses. For the realization of the kinematic tests, a prototype 5 DoF upper-limb exoskeleton previously proposed in the literature [6] is used as an example. One of the secondary objectives, is the use of inverse kinematics, forward kinematics and orientation that allow determining the orientation and translation workspace [52], and the joint angles of the upper-limb exoskeleton and the virtual object.…”

An innovative equivalent kinematic model of the human upper limb to improve the trajectory planning of exoskeleton rehabilitation robots

“…Upper limb exoskeleton rehabilitation robots have become more popular because they can not only provide adaptive training and highly repetitive motion but also enhance the self-care capabilities of patients with a loss of motor function (Jarrasse et al, 2010;Côté-Allard et al, 2018;Zhang et al, 2018). The design of upper limb exoskeletons should be especially considered because they interact directly with the human body (Esmaeili et al, 2011;Gopura et al, 2011). The number of degrees of freedom (DOF), range of motion (ROM) of joints, safety, comfort, low inertia, and adaptabil-ity to the human body should be especially considered in the design of these exoskeletons (Meng et al, 2018;Maciejasz et al, 2014).…”