Developments in circular external fixators: A review.

Circular external fixators (CEFs) are successfully used in orthopedics owing to their highly favorable stiffness characteristics which promote distraction osteogenesis. Although there are different designs of external fixators, how these features produce optimal biomechanics through structural and component designs is not well known. Therefore, the aim of this study was to conduct a review on CEFs following the PRISMA statement. A search for relevant research articles was performed on Scopus and PubMed databases providing the related keywords. Furthermore, a patent search was conducted on the Google Patent database. 126 records were found to be eligible for the review. Different designs of CEFs were summarized and tabulated based on their specific features. A bibliometric analysis was also performed on the eligible research papers. Based on the findings, the developments of CEFs in terms of materials, automation, adjustment methods, component designs, wire-clamping, and performance evaluation have been extensively discussed. The trends of the CEF design and future directions are also discussed in this review. Significant research gaps include a lack of consideration towards ease of assembly, effective wire-clamping methods, and CEFs embedded with online patient-monitoring systems, among others. An apparent lack of research interest from low-middle and low-income countries was also identified.

An Intelligent Gesture Classification Model for Domestic Wheelchair Navigation with Gesture Variance Compensation.

Elderly and disabled population is rapidly increasing. It is important to uplift their living standards by improving the confidence towards daily activities. Navigation is an important task, most elderly and disabled people need assistance with. Replacing human assistance with an intelligent system which is capable of assisting human navigation via wheelchair systems is an effective solution. Hand gestures are often used in navigation systems. However, those systems do not possess the capability to accurately identify gesture variances. Therefore, this paper proposes a method to create an intelligent gesture classification system with a gesture model which was built based on human studies for every essential motion in domestic navigation with hand gesture variance compensation capability. Experiments have been carried out to evaluate user remembering and recalling capability and adaptability towards the gesture model. Dynamic Gesture Identification Module (DGIM), Static Gesture Identification Module (SGIM), and Gesture Clarifier (GC) have been introduced in order to identify gesture commands. The proposed system was analyzed for system accuracy and precision using results of the experiments conducted with human users. Accuracy of the intelligent system was determined with the use of confusion matrix. Further, those results were analyzed using Cohen's kappa analysis in which overall accuracy, misclassification rate, precision, and Cohen's kappa values were calculated.

ChairX: A Robotic Exoskeleton Chair for Industrial Workers.

This paper proposes a robotic exoskeleton chair, named ChairX, for providing sitting assistance for the industrial workers who need to carry out tasks at different crouched postures repetitively. It can act as a customizable chair to support bodyweight for relieving the lower extremity and provide freedom for ambulation when moving between workstations. In comparison to the predecessors, the ChairX is designed to assist the user for assuming crouched positions with forward- as well as backward-inclined leg angles. Moreover, it is flexible to provide sitting assistance at different heights to ensure ergonomics at work The ChairX includes a knee-centered locking mechanism on the lateral side and an active linkage mechanism on the posterior of the leg to support the weight of the user at various seated positions. A mathematical model was formulated to optimize the system parameters and a prototype was built to carry out the physical tests. The results revealed that ChairX can maintain stability and reduce the musculoskeletal strains effectively, thus has the potential to improve the quality of work.

MoBio: A 5 DOF trans-humeral robotic prosthesis.

In this paper, a 5 DOF trans-humeral robotic prosthesis: MoBio is proposed. MoBio includes 2 DOF at wrist which is rare in other trans-humeral prostheses. Through anthropometric features MoBio prosthetic arm can achieve elbow flexion/extension, forearm supination/pronation, wrist radial/ulnar deviation, wrist flexion/extension and compound motion of thumb and index finger. An EMG based control method which uses EMG signals of the biceps brachii and triceps brachii, is used with a motion switching mechanism to control the prosthesis. Experimental results have verified the usability and effectiveness of MoBio in performing Activities of Daily Living.

Development of a multi-DoF transhumeral robotic arm prosthesis.

An anthropomorphic transhumeral robotic arm prosthesis is proposed in this study. It is capable of generating fifteen degrees-of-freedom, seven active and eight passive. In order to realize wrist motions, a parallel manipulator-based mechanism is proposed. It simulates the human anatomical structure and generates motions in two axes. The hand-of-arm prosthesis consists of under-actuated fingers with intrinsic actuation. The finger mechanism is capable of generating three degrees of freedom, and it exhibits the capability of adjusting the joint angles passively according to the geometry of the grasping object. Additionally, a parameter to evaluate finger mechanisms is introduced, and it measures the adoptability of a finger mechanism. In order to verify the mechanism's efficacy in terms of motion generation, motion simulation and kinematic analysis were carried out. Results demonstrated that the mechanisms are capable of generating the required motions.