A Novel 3D Printed Wrist Rehabilitation Robot: Design, Development and Optimal Trajectory Planning

Rehabilitation of patients suffering after stroke impairment is a lengthy process and requires experienced therapists. These limitations have led to the introduction of rehabilitation robots that can operate for a longer time while eliminating the lack of professional therapists. In this thesis, we propose a two-degrees-of-freedom robot for wrist rehabilitation, referred to as MOCH. The MOCH mechanism comprises a remote center of motion (RCM) mechanism with a rotation center outside of the robot structure. When the patient holds the robot end-effector, coinciding the RCM of the robot with the rotation axis of the wrist, allows pure rotational motion of the hand. As the RCM lies out of the robot structure, there is less risk of interference with the patient. Furthermore, MOCH benefits a novel actuation that enables the actuators to be grounded, reducing the inertia and the size of the robot. The optimal design of MOCH is provided considering the mechanical criteria and requirements of the wrist rehabilitation. Based on the proposed design, a prototype of the robot is developed with a total mass of 1.3 kg using 3D printing technology. Additionally, we introduce a novel methodology for passive rehabilitation exercise, exploiting the wrist dynamics which removes the complexity of force/impedance control approaches. This method involves designing an optimal trajectory within the limits of the wrist motion, and to keep the applied torque on the patient's hand in a safe range without using force sensors. The proposed trajectory is tested on a healthy individual using the implemented prototype

Analysis of Voiceprint and Other Biometrics for Criminological and Security Applications

This Thesis examines the role and limitations of voice biometrics in the contexts of security and for crime reduction. The main thrust of the Thesis is that despite the technical and non-technical hurdles that this research has identified and sought to overcome, voice can be an effective and sustainable biometric if used in the manner proposed here. It is contended that focused and continuous evaluation of the strength of systems within a solid framework is essential to the development and application of voice biometrics and that special attention needs to be paid to human dimensions in system design and prior to deployment. Through an interdisciplinary approach towards the theme reflected in the title several scenarios are presented of the use of voice in security / crime reduction, crime investigation, forensics and surveillance contexts together with issues surrounding their development and implementation. With a greater emphasis on security-oriented voice verification (due to the diversity of the usage scenarios and prospect of use) a new framework is presented for analysis of the reliability and security of voice verification. This research calls not only for a standard evaluation scheme and analytical framework but also takes active steps to evaluate the prototype system within the framework under various conditions. Spoof attacks, noises, coding, distance and channel effects are among the factors that are studied. Moreover, an additional under-researched area, the detection of counterfeit signals, is also explored. While numerous technical and design contributions made in this project are summarised in chapter 2, the research mainly aims to provide solid answers to the high-level strategic questions. The Thesis culminates in a synthesis chapter in which realistic expectations, design requirements and technical limitations of the use of voice for criminological and security applications are outlined and areas for further research are defined

Toward a dynamic framework for security evaluation of voice verification systems

Research results have shown that spoof attacks pose severe security threats to biometric verification systems. Nevertheless the literature lacks a comprehensive, flexible and dynamic framework for security analysis of biometric and especially voice based verification systems when spoof attacks are taken into picture. This paper aims at highlighting the vulnerabilities, classifying the threats and clarifying requirements for such a dynamic framework which transfers the vulnerability evaluation results into legacy knowledge in the security domain. The proposed design and architecture facilitates comparison of two systems as well as definition of the threats in an independent and isolated way

COVID-19 vaccines breakthrough infection and adverse reactions in medical students: a nationwide survey in Iran

IntroductionThere are different types of COVID-19 vaccines approved worldwide. Since no national studies focus on vaccine-related adverse reactions and breakthrough cases, this study aimed to investigate the rate of adverse events and COVID-19 infection in medical students in Iran.MethodsThis retrospective cohort study included Iranian medical students who received two doses of COVID-19 vaccines. The medical team gathered the demographic characteristics, comorbidities, type of vaccine, adverse events following vaccination, and history of COVID-19 infection data through a phone interview. The frequency of adverse events and breakthrough infection was stratified by vaccine type (ChAdOx1-S, Gam-COVID-Vac, and BIBP-CorV).ResultsA total of 3,591 medical students enrolled in this study, of which 57.02% were females, with a mean age of 23.31 + 4.87. A PCR-confirmed and suspicious-for-COVID-19 breakthrough infection rate of 4.51 and 7.02% was detected, respectively. There was no significant relation between breakthrough infection and gender, BMI, blood groups, and comorbidities. However, there was a significant difference in breakthrough infection rate among different types of vaccines (p = 0.001) and history of COVID-19 infection (p = 0.001). A total of 16 participants were hospitalized due to COVID-19 infection after vaccination for reasons such as dyspnea, abnormal imaging, or decreased oxygen saturation. No severe infection or death was observed in the studied population.ConclusionVaccination prevented severe COVID-19 infection, although a high breakthrough infection rate was evident among Iranian medical students during the Delta variant’s peak. Vaccine effectiveness may be fragile during emerging new variants and in high-exposure settings. Moreover, adverse events are rare, and the benefits of vaccination outweigh the side effects. However, many limitations challenged this study, and the results should be cautious