Optimal dimensional synthesis of force feedback lower arm exoskeletons

This paper presents multi-criteria design optimization of parallel mechanism based force feedback exoskeletons for human forearm and wrist. The optimized devices are aimed to be employed as a high fidelity haptic interfaces. Multiple design objectives are discussed and classified for the devices and the optimization problem to study the trade-offs between these criteria is formulated. Dimensional syntheses are performed for optimal global kinematic and dynamic performance, utilizing a Pareto front based framework, for two spherical parallel mechanisms that satisfy the ergonomic necessities of a human forearm and wrist. Two optimized mechanisms are compared and discussed in the light of multiple design criteria. Finally, kinematic structure and dimensions of an optimal exoskeleton are decided

Design optimization and control of a parallel lower-arm exoskeleton

Wearable force feedback robotic devices, haptic exoskeletons, are becoming increasingly common as they find widespread use in medical and virtual reality (VR) applications. Allowing users to mechanically interact with computationally mediated environments, haptic exoskeletons provide users with better “immersion” to VR environments. Design of haptic exoskeletons is a challenging task, since in addition to being ergonomic and light weight, such devices are also required to satisfy the demands of any ideal force-feedback device: ability withstand human applied forces with very high stiffness and capacity to display a full range of impedances down to the minimum value human can perceive. If not properly designed by taking these conflicting requirements into account, the interface can significantly deteriorate the transparency of displayed forces; therefore, the choice of the kinematic structure and determination of the dimensions of this kinematic structure have significant impacts on the overall performance of any haptic display independent of the control algorithm employed. In this thesis, we first propose a general framework for optimal dimensional synthesis of haptic interfaces, in particular for haptic interfaces with closed kinematic chains, with respect to multiple design objectives. We identify and categorize the relevant performance criteria for the force feedback exoskeletons and address the trade-offs between them, by applying a Pareto-front based multi-objective design optimization procedure. Utilizing a fast converging gradient-based method, the proposed framework is computational efficient. Moreover, the approach is applicable to any set of performance indices and extendable to include any number of design criteria. Subsequently, we extend this framework to assist the selection of the most appropriate kinematic structure among multiple mechanisms. Specifically, we perform a rigorous comparison between two spherical parallel mechanisms (SPMs) that satisfy the ergonomic necessities of a human forearm and wrist and select the kinematic structure that results in superior performance for force-feedback applications. Utilizing the Pareto optimal set of solutions, we also assign dimensions to this mechanism to ensure an optimal trade-off between global kinematic and dynamic performance. Following the design optimization phase, we perform kinematic and dynamic analyses of the SPM-based exoskeleton in independent coordinates to facilitate efficient simulation and real-time implementation of model based controllers. We decide on the hardware components considering human wrist torque and force limits, safety and ergonomy constraints, and present the CAD model of a prototype of the exoskeleton. Finally, we implement model based task-space position and impedance controllers in simulation and present the results of them

Effect of the COVID-19 Pandemic on Eating Habits and Food Purchasing Behaviors of University Students

COVID-19 disease, which spread rapidly all over the world after the first case was detected, became the primary agenda of the countries. Radical measures have been taken by governments to prevent the spread of the disease. Precautions and warnings to prevent disease caused some changes on daily life activities of people. University students who have to stop education are among the groups most affected by this disease sociologically, psychologically and physiologically. The aim of this study was planned and conducted to determine the effect of COVID-19 on university students' eating habits and food purchasing behavior. The study was completed with 866 university students education and training at the faculty of health sciences. Research data was obtained by online questionnaire. This questionnaire has been prepared with the information obtained as a result of the literature review and the opinions of experts by researchers. The questionnaire includes questions about eating habits and food purchasing behaviors. A result of the study, COVID-19 disease caused significant changes in the eating habits and food purchasing behaviors of university students. In general, it was found that the participants increased their consumption compared to before COVID-19, they paid more attention to hygiene while food purchasing

I-BaR: Integrated Balance Rehabilitation Framework

Neurological diseases are observed in approximately one billion people worldwide. A further increase is foreseen at the global level as a result of population growth and aging. Individuals with neurological disorders often experience cognitive, motor, sensory, and lower extremity dysfunctions. Thus, the possibility of falling and balance problems arise due to the postural control deficiencies that occur as a result of the deterioration in the integration of multi-sensory information. We propose a novel rehabilitation framework, Integrated Balance Rehabilitation (I-BaR), to improve the effectiveness of the rehabilitation with objective assessment, individualized therapy, convenience with different disability levels and adoption of an assist-as-needed paradigm and, with an integrated rehabilitation process as a whole, i.e., ankle-foot preparation, balance, and stepping phases, respectively. Integrated Balance Rehabilitation allows patients to improve their balance ability by providing multi-modal feedback: visual via utilization of Virtual Reality; vestibular via anteroposterior and mediolateral perturbations with the robotic platform; proprioceptive via haptic feedback.Comment: 37 pages, 2 figures, journal pape

Conceptual Design of a Fully Passive Transfemoral Prosthesis to Facilitate Energy-Efficient Gait

In this study, we present the working principle and conceptual design towards the realization of a fully-passive transfemoral prosthesis that mimics the energetics of the natural human gait. The fundamental property of the conceptual design consists of realizing an energetic coupling between the knee and ankle joints of the mechanism. Simulation results show that the power flow of the working principle is comparable to that in human gait and a considerable amount of energy is delivered to the ankle joint for the push-off generation. An initial prototype in half scale is realized to validate the working principle. The construction of the prototype is explained together with the test setup that has been built for the evaluation. Finally, experimental results of the prosthesis prototype during walking on a treadmill show the validity of the working principle

The prevalence of vertigo among high school students and an evaluation of quality of life

Background: The purpose of the study is to determine the prevalence of vertigo among secondary and high school students, to examine the variables thought to be related and to evaluate the quality of life.Methods: This study was carried out between 1st November-30th December 2016 on secondary and high school students in Beylikova and Sivrihisar counties which is located at the research area of the Department of Public Health Eskisehir Osmangazi University. Those who had dizziness within the last three months have been assumed as having vertigo. Visual Analog Scale has been used in order to evaluate the severity of vertigo. The life quality of children has been evaluated through Quality of Life Scale (QoL) for Children.Results: The study group has been composed of 911 males (46.5%) and 1.047 females (53.5%). The prevalence of vertigo has been determined as 30.8%. The most common concomitant symptoms of students are headache (22.6%), staggering while walking (15.8%), and tinnitus (10.3%).It has been found that the QoL of students having complaints of vertigo is lower than that of those not having complaints of vertigo. The most common type of vertigo within the study group has been Orthostatic Dizziness (70.0%). There has been no correlation between types of vertigo and QoL; however, when the severity of vertigo is considered, it has been found within our study group that the QoL of the students having mild vertigo is higher than that of those having moderate or higher severity of vertigo(p<0.05.Conclusions: Vertigo is one of the most common symptoms among children and adolescents and may result from many factors. It may be useful to carry out screening with the purpose of early diagnosis and treatment parentheses, direct diagnosed cases to specialist physicians and organize events to create awareness. More comprehensive studies are needed to reveal the relationship between vertigo and QoL

Herpes zoster infection in early adolescence: two case reports and review of the treatment approach

Introduction: Herpes zoster is a skin infection caused by reactivation of the Varicella zoster virus that remains latent in the dorsal root ganglia, showing dermatomal spread on the skin, accompanied by a vesicular rash and itching. It is a disease of the adult age group. Although herpes zoster is more common in immunocompromised children, it is rarely seen in healthy children. Case Presentation: Two patients, 11 and 12 years old, presented with pain, itching, and rash. Patient histories indicated that they were previously healthy. Alanine aminotransferase, aspartate aminotransferase, urea, blood urea nitrogen, creatinine, and electrolyte values were within normal limits. Varicella-zoster virus (VZV) immunoglobulin (Ig) G and VZV Ig M were positive, while herpes zoster virus (HZV) Ig G and HZV Ig M were negative. Oral acyclovir treatment was started. Symptoms, treatment, and follow-up of the two cases were similar. In both patients, the lesions regressed within a week, and at the end of the second week, they recovered without complications.Conclusion: Herpes Zoster infection is rarely seen in healthy children. In this case report, we aimed to remind and discuss the clinical features during childhood

DNA Repair Gene Polymorphism and the Risk of Mitral Chordae Tendineae Rupture

Polymorphisms in Lys939Gln XPC gene may diminish DNA repair capacity, eventually increasing the risk of carcinogenesis. The aim of the present study was to evaluate the significance of polymorphism Lys939Gln in XPC gene in patients with mitral chordae tendinea rupture (MCTR). Twenty-one patients with MCTR and thirty-seven age and sex matched controls were enrolled in the study. Genotyping of XPC gene Lys939Gln polymorphism was carried out using polymerase chain reaction-(PCR-) restriction fragment length polymorphism (RFLP). The frequencies of the heterozygote genotype (Lys/Gln-AC) and homozygote genotype (Gln/Gln-CC) were significantly different in MCTR as compared to control group, respectively (52.4% versus 43.2%, = 0.049; 38.15% versus 16.2%, = 0.018). Homozygote variant (Gln/Gln) genotype was significantly associated with increased risk of MCTR (OR = 2.059; 95% CI: 1.097-3.863; = 0.018). Heterozygote variant (Lys/Gln) genotype was also highly significantly associated with increased risk of MCTR (OR = 1.489; 95% CI: 1.041-2.129; = 0.049). The variant allele C was found to be significantly associated with MCTR (OR = 1.481; 95% CI: 1.101-1.992; = 0.011). This study has demonstrated the association of XPC gene Lys939Gln polymorphism with MCTR, which is significantly associated with increased risk of MCTR

A Soft+Rigid Hybrid Exoskeleton Concept in Scissors-Pendulum Mode: A Suit for Human State Sensing and an Exoskeleton for Assistance

In this paper, we present a novel concept that can enable the human aware control of exoskeletons through the integration of a soft suit and a robotic exoskeleton. Unlike the state-of-the-art exoskeleton controllers which mostly rely on lumped human-robot models, the proposed concept makes use of the independent state measurements concerning the human user and the robot. The ability to observe the human state independently is the key factor in this approach. In order to realize such a system from the hardware point of view, we propose a system integration frame that combines a soft suit for human state measurement and a rigid exoskeleton for human assistance. We identify the technological requirements that are necessary for the realization of such a system with a particular emphasis on soft suit integration. We also propose a template model, named scissor pendulum, that may encapsulate the dominant dynamics of the human-robot combined model to synthesize a controller for human state regulation. A series of simulation experiments were conducted to check the controller performance. As a result, satisfactory human state regulation was attained, adequately confirming that the proposed system could potentially improve exoskeleton-aided applications

Optimal Dimensional Synthesis of a Dual Purpose Haptic Exoskeleton

This paper presents multi-criteria design optimization of a 3RPS-R parallel mechanism to be employed as a dual purpose haptic exoskeleton for human forearm and wrist. The primary use for the optimized device is aimed as a high fidelity haptic interface, while the exoskeleton can also be employed as a rehabilitation device. Multiple design objectives are discussed and classified for both application scenarios, and optimization problems to study the trade-offs between these criteria are formulated. A general framework for optimization of haptic interfaces is applied to efficiently obtain the Pareto-front hyper-surfaces between conflicting criteria. Optimal dimensional synthesis of the dual purpose haptic exoskeleton is demonstrated