Robotic Home-Based Rehabilitation Systems Design: From a Literature Review to a Conceptual Framework for Community-Based Remote Therapy During COVID-19 Pandemic

During the COVID-19 pandemic, the higher susceptibility of post-stroke patients to infection calls for extra safety precautions. Despite the imposed restrictions, early neurorehabilitation cannot be postponed due to its paramount importance for improving motor and functional recovery chances. Utilizing accessible state-of-the-art technologies, home-based rehabilitation devices are proposed as a sustainable solution in the current crisis. In this paper, a comprehensive review on developed home-based rehabilitation technologies of the last 10 years (2011–2020), categorizing them into upper and lower limb devices and considering both commercialized and state-of-the-art realms. Mechatronic, control, and software aspects of the system are discussed to provide a classified roadmap for home-based systems development. Subsequently, a conceptual framework on the development of smart and intelligent community-based home rehabilitation systems based on novel mechatronic technologies is proposed. In this framework, each rehabilitation device acts as an agent in the network, using the internet of things (IoT) technologies, which facilitates learning from the recorded data of the other agents, as well as the tele-supervision of the treatment by an expert. The presented design paradigm based on the above-mentioned leading technologies could lead to the development of promising home rehabilitation systems, which encourage stroke survivors to engage in under-supervised or unsupervised therapeutic activities

Practical and analytical studies on the development of formal evaluation and design methodologies for mechatronic systems

The integration of mechanical engineering, electrical engineering and information technology in one mixed system has found vast applications in industry and everyday life. This interdisciplinary field, known as Mechatronics, has attracted a great deal of attention, particularly in the context of optimal design of multi-domain systems. To this end, the present thesis represents an original investigation into the development of formal and systematic methodologies for the optimal design and design evaluation of mechatronic systems. This work presents a new philosophy and approach for the optimal design of mechatronic systems. It takes into account that an optimal mechatronic design requires concurrent, integrated, and system-based thinking with regard to all design parameters and criteria involved in the mechatronic system. The mathematical model and axioms which support this thinking are presented in the thesis. A design evaluation index has been presented in the present work which supports above statement. It is based on the concept of mechatronic design quotient (MDQ). MDQ is a multi-criteria index reflecting the overall degree of satisfaction of the design criteria for a mechatronic system. In this thesis, a nonlinear fuzzy integral is used for the aggregation of the various design criteria and for handling possible correlations among them. For an existing mechatronic system, MDQ is a useful index for evaluating its design as well, and determining the potential for improvement. In different stages of design, it can be used as an index for the purposes of optimization and/or decision making. In the present work, a new systematic mechatronic design methodology based on the concept of MDQ maximization is presented. The design procedure is treated in multiple stages. In the conceptual stage, MDQ provides guidance to the designer in selecting the best design choices and making effective decisions about the essential structure of the design. In the next stage, which concerns detailed design, a niching genetic algorithm is employed to find the elite design alternatives for all possible configurations and combinations of system parts. Since a full MDQ assessment is computationally expensive, it is not practical to consider all MDQ attributes in the course of an evolutionary optimization. Only the essential criteria which have a veto effect on the MDQ evaluation are considered in the process of the niching genetic algorithm. A full and detailed MDQ assessment is then employed to find the best choice among the elite representatives. The reliability assessment of mechatronic systems is studied as well in the thesis. A new reliability assessment methodology is developed which has two practical advantages over the available methodologies. First, in view of dynamic interactions that may exist in a mechatronic system, the developed method uses a Petri-net simulation of the dynamic behavior of the system. Here, all possible events and conditions of the real operation of the system and all possible interactions can be accurately modeled in the level of detail that the designer prefers. Second, the severity of the failure modes is considered in the reliability evaluation methodology. The developed reliability evaluation approach contributes in the mechatronic design process by revealing information about the performance of various design choices. A bond graph mechatronic simulation tool is developed in this work. It is based on a new matrix-based formulation, which is presented in the thesis. The bond graph simulation tool is integrated with genetic programming to form a unified evolutionary mechatronic tool. As a new contribution, this synergic integration is extended for the general case of nonlinear mechatronic problems. This tool can concurrently optimize both the topology and "size" of a bond graph model of a mechatronic system in order to achieve the best fitness for the solution. It can be used in any mechatronic problem, provided that an effective fitness evaluation is established for the problem. In particular, the application of this tool for automated system identification of nonlinear mechatronic systems is presented in the thesis. The methodologies developed in this research are validated by applying them to the modeling and redesign process of an industrial fish processing machine, called the Iron Butcher - a complex electromechanical system which falls into the class of mixed or multi-domain systems.Applied Science, Faculty ofMechanical Engineering, Department ofGraduat

A novel Lyapunov function for stability of haptic device in simulating virtual objects

One of the main challenges of simulating virtual objects by haptic devices is instability, especially in simulating stiff objects. In this paper, a stability criterion for a haptic device is derived using Lyapunov approach. The haptic device is modeled as a mass and viscous friction, which has to simulate the touching a virtual environment (VE) with specified stiffness and damping. Dynamic equations and state-space equations are derived with assumption of small values of sampling time, time delay and virtual damping. A Lyapunov function is proposed, consisting of summation of kinetic and potential energy of the system, plus two unknown terms. Each one of these two unknown terms is a function of one system states (i.e. position and velocity). These two functions are determined so that, from one side the Lyapunov function be positive definite, and from the other side the stability criterion is reached with putting time derivation of the Lyapunov function negative. The stability condition determined by this method is a linear criterion between maximum permissible virtual stiffness, virtual damping of the VE, physical damping of the haptic device, sampling time and time delay, and is consistent with the results of previous researches with linear methods. The importance of the presented analysis in this paper is that this method can be extended by adding new terms to the Lyapunov function, to remove some limitations and to take into account nonlinear effects. Presented criterion and its results are verified by experiments on KUKA robot

Effect of and the association between vitamin D and outcomes of assisted reproductive techniques among infertile men and women: protocol for an overview of systematic reviews and meta-analysis

Introduction Vitamin D is associated with many functions of the human reproductive system. Accordingly, it seems that on infertile couples undergoing assisted reproduction technology (ART), treatment outcomes may be affected by the vitamin D. This overview aims to show the effect of vitamin D on infertility treatments outcomes in recent studies by concluding systematic reviews and meta-analyses to achieve a comprehensive result.Methods and analysis This overview protocol is being reported according to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) statement and was registered in the International Prospective Register of Systematic Reviews. We will include all peer-reviewed systematic reviews and meta-analyses of randomised controlled trials published from inception until December 2022. PubMed, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Database of Abstracts of Reviews of Effects, Scopus, Cochrane Central Register of Controlled Trials and Embase will be searched from the time of publication of the first articles onwards with a comprehensive search strategy. Endnote V.X7 software (Thomson Reuters, New York, New York, USA) will be used to store and manage records. The results will align with guidelines in the Cochrane Handbook of Systematic Reviews of Interventions and the PRISMA statement.Ethics and dissemination This overview will be evaluating the effect of vitamin D status and vitamin D supplementing on results of ART in women and men who are undergoing treatment for infertility. The high prevalence of vitamin D deficiency worldwide and its effects on an important issue such as human fertility might be a very influential factor that leads scientists to strongly recommend its use. However, the more critical concern is that there is no definitive agreement in studies on the relationship between vitamin D and an increased chance of better fertility in men and women undergoing infertility treatment.PROSPERO registration number CRD42021252752

Level-locked loop: a technique for broadband quadrature signal generation

A method for precise wideband quadrature signal generation is presented. A divide-by-2 stage forms an adjustable phase quadrature signal generator. Its output phase error is converted to an error signal, which feeds back to the quadrature signal generator through an integrator, to correct the output phase difference. Using this method, a phase accuracy better than 0.5° is achieved over 40 MHz to 500 MHz of output frequency without any external tuning. The loop compensates for any circuit and layout mismatches, is not sensitive to distorted input LO signals, and has no inherent high frequency limitation