Design of a passive, iso-elastic upper limb exoskeleton for gravity compensation

An additional mechanical mechanism for a passive parallelogram-based exoskeleton arm-support is presented. It consists of several levers and joints and an attached extension coil spring. The additional mechanism has two favourable features. On the one hand it exhibits an almost iso-elastic behaviour whereby the lifting force of the mechanism is constant for a wide working range. Secondly, the value of the supporting force can be varied by a simple linear movement of a supporting joint. Furthermore a standard tension spring can be used to gain the desired behavior. The additional mechanism is a 4-link mechanism affixed to one end of the spring within the parallelogram arm-support. It has several geometrical parameters which influence the overall behaviour. A standard optimisation routine with constraints on the parameters is used to find an optimal set of geometrical parameters. Based on the optimized geometrical parameters a prototype was constructed and tested. It is a lightweight wearable system, with a weight of 1.9 kg. Detailed experiments reveal a difference between measured and calculated forces. These variations can be explained by a 60% higher pre load force of the tension spring and a geometrical offset in the construction

Exoskeletons in industry : designs and their potential

The main goals for exoskeletons in an industrial setting is summarised. By using two design examples of arm exoskeletons to support workers in manual handling tasks, the potentials for the near future are explained

Basic functionality of a prototype wearable assistive soft exoskeleton for people with gait impairments : a case study

XoSoft is a soft modular wearable assistive exoskeleton for peo- ple with mild to moderate gait impairments. It is currently being developed by a European Consortium (www.xosoft.eu) and aims to provide tailored and active lower limb support during ambu- lation. During development, user-centered design principles were followed in parallel with the aim of providing functional support during gait. A prototype was developed and was tested for practi- cability, usability, comfort and assistive function (summarized as basic functionality) with a potential end user. The prototype con- sisted of a garment, electromagnetic clutch-controlled elastic bands supporting knee- and hip flexion and a backpack containing the sensor and actuator control of the system. The participant had ex- perienced a stroke and presented with unilateral impairment of the lower and upper extremities. In testing, he donned and doffed the prototype independently as far as possible, and performed walk- ing trials with the system in both active (powered on) and pas- sive (powered off) modes. Afterwards, the participant rated the perceived pressure and various elements of usability. Results high- lighted aspects of the system for improvement during future phases of XoSoft development, and also identified useful aspects of proto- type design to be maintained. The basic functionality of XoSoft could be assumed as satisfactory given that it was the first version of a working prototype. The study highlights the benefits of this participatory evaluation design approach in assistive soft robotics development

Sensors requirements for robust single plant detection in real time

This paper considers theoretical prerequisites for the sensor or sensor system that provides data for reliable single plant detection. The goal of the paper is to close the gap between the state of the art sensor technology and the theoretical “ideal” sensor to fulfill one and only purpose: providing single plant detection data in cluttered and disordered environments. Through analysis of artificial leaf forms, the paper determines expectations of the sensor spatial resolution and its maximum noise level. Supported by the results of a theoretical primer on predefined (artificial) shape analysis, an in-depth evaluation compares the results of 3D shape analysis with results obtained through 2D digital image processing. To analyze leaf shapes reliably, a minimum sensor resolution (2D and 3D) is determined by means of statistical feature analysis. As a final result of the paper, methods for sensor selection are pro-posed with regard to the specific task of analyzing leaf shape in real time

Medical Student’s Perception of The Deployment of Interactive Whiteboards for Problem Based Learning

Background: Interactive whiteboards (IWB) were introduced in all the classrooms used for problem based learning (PBL) sessions within the University of Geneva faculty of medicine at the beginning of 2014. Students were surveyed at the end of the following semester to evaluate their perception and use of IWBs, and measure IWBs’ impact on PBL process, students’ motivation, and group functioning. Method: Bachelor students of Years 2 and 3 answered a 61-item self-administered online survey exploring eight themes: IWB launching, IWB use, practice of the writing and drawing software, role of the secretary, PBL process, personal interaction with IWB, group functioning, and socio-demographic data. Results: 236 students (71.7%) completed the survey. Globally students found IWBs as well as the text editor easy to use (mean 4.8± 0.9 standard deviation; easier for men, p=.007; and 4.9±0.9 on a 1 to 6 Likert scale). Other functionalities were occasionally or rarely used, as well as the integration of learning materials (articles, book chapter, and websites) in the notebook. When compared to the situation before the deployment of IWBs, students did not report higher motivation (3.2±1.4), more concentration (3.2±1.4), more creativity (3.7±1.6), better understanding (3.2±1.3), or better memorization of what was displayed in the board (3.3±1.4). They agreed that the use of multimedia learning resources was facilitated (4.9±1.1), the material produced by the group was richer in drawings, images, abstracts (4.3±1.4), but did not think the group was better organised (3.6±1.4) nor that the elements discussed were more precise (3.6±1.4). After the first phase of a PBL session, the electronic notes were used by the majority of the students to complete their own documentation. They were however not used more frequently than before (3.2±1.7), and only used sometimes as a starting point for the reporting phase of the PBL session (2.1±0.8). Conclusions: The implementation of IWBs within the institution was rather positively welcomed by students. Whereas they deemed the material produced by the group was enriched when compared to the situation without IWBs, there was no evidence, neither at the individual, nor at the groups’ level, of a significant change regarding the learning process and organisatio

Analysis of off-the-shelf stereo camera system bumblebee XB3 for the fruit volume and leaf area estimation

The paper describes a set of simulated and real-world experiments to determine the total leaf area and fruit volume of a fruit tree using 3-dimensional data gathered from colour stereo images. Initially, the accuracy of the stereo algorithms is determined, and then the method for leaf area computation is developed and tested on particular trees with a known leaf area. Finally, leaf area computation is carried out on a number of images of real fruit trees obtained in the ICT-AGRI project 3D-Mosaic. Furthermore, limitations of the system are shown using the example of fruit volume and leaf area computation from orchard data. Several stereo algorithms are compared with regard to their accuracy and performance. The experimental system consisting of several sensors and software components is briefly explained, enabling rebuilding of the system with minimum effort with respect to construction and software development. Lastly, recommendations are proposed for the scientific and industrial teams interested in similar problems on selecting sensors and open-source and BSD software components to successfully approach this complex problem

E-learning modules to improve clinical reasoning and practice : a prospective comparative study

Background: Controversy remains about whether e-learning can improve clinical competences. Our study aimed to compare the effects of e-learning versus traditional education on medical students' reasoning and how they applied their knowledge to clinical competences, assess factors associated with e-learning that might influence exam scores, and evaluate medical students' satisfaction with these two learning methods. Methods: Prospective study of 299 medical students in two fourth-year pediatric clerkship cohorts (2016-17 and 2017-18) in Switzerland. Results: We found no evidence of a difference in students' reasoning or how they applied their knowledge to competences in clinical case resolution, whether they had followed e-learning modules or attended traditional lectures. The number of quizzes taken and being female were factors associated with better scores. Even though overall satisfaction with the two learning methods was similar, students claimed that they learned more in e-learning than in traditional lectures and that e-learning explained learning objectives better. Conclusions: E-learning could be used as a supplement or alternative to traditional face-to-face medical teaching methods without compromising teaching quality. E-learning modules should be better integrated into medical students' curricula but avoid the risk of curriculum overload, especially in case of repeated COVID-like context.</p