594 research outputs found

    Design of a Lightweight Modular Powered Transfemoral Prosthesis

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    Rehabilitation options for transfemoral amputees are limited, and no product today can mimic the full functionality of a human limb. Powered prosthetics have potential to close this gap but contain major drawbacks which ultimately increase the energy expenditure of the user. This thesis explores the viability of new designs and methods to reduce energy expenditure. In doing so a prototype containing many of the explored concepts is also being constructed to replace the laboratory’s current powered prosthetic, AMPRO II. This goal is accomplished by reducing weight through optimizing structural components, using lightweight motors and gearing, and reducing the energy requirements through novel passive spring sub-assemblies. Adjustable and modular components also enable a wider range of use and are explored. The main objective of this thesis is to investigate these design improvements and create the next-generation prosthetic for the Human Rehabilitation Lab. This thesis explores using a combination of passive and powered components to reduce the need for heavy actuators. Methods involve coding walking simulations based on an inverse dynamics study. By simulating design concepts with elastic elements the resulting power requirements of the motors have been estimated to evaluate each concept. Motors and gearing options have also been investigated with an optimization-based approach; gearing ratio was minimized in a test comparing discrete off-the-shelf motor options to biomechanical requirements. For the structural components, the mass of each part has been minimized through an iterative approach in FEA. Elements selected for further investigation from this thesis are being constructed with a prototype. Improvements over AMPRO II include adjustable height, functionality on both legs, a flexible foot, modularity, capabilities of passive elastic elements, and a mass estimated to be 20% lighter. Components include flat motors with harmonic drives, adjustable pylons for height, a low-profile mounting frame, passive pre-loaded springs, and a rotary series elastic actuator (RSEA). Unproven concepts such as the springs and RSEA have been designed as modular and optional to reduce risk. Moving forward, the first prototype is currently being built without the optional components to test the biomechanics. Future tests will incorporate the designed elastic elements to validate simulation concepts

    Spatial pattern analysis of police use of force: Exploratory findings

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    Relative to American culture and justice today is the issue of police using force on citizens to control a situation. Many believe the use of force by police can be excessive and it has changed police-citizen interactions. Currently, much of the research into the topic has been limited, and often shows conflicting results with unclear conclusions. To better understand the influences of police use of force, this study uses qualitative and quantitative methods to examine spatial patterning that may help explain which factors contribute to a use of force event. Taking information provided by a police department of a mid-sized city in the western United States, this study analyses reports of use of force by mapping cases and determining significant clusters that develop based on numerous variables. Results show incidents of use of force cluster around the downtown area of the region and suggests neighborhood contexts which lead to police using forc

    β-diketonate versus β-ketoiminate:the importance of a ferrocenyl moiety on improving the anticancer potency

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    Herein we present a library of fully characterized beta-diketonate and beta-ketoiminate compounds that are functionalized with a ferrocenyl moiety. Their cytotoxic potential has been determined by screening against human breast adenocarcinomas (MCF-7 and MDA-MB-231), human colorectal carcinoma p53 wild type (HCT116 p53(+/+)) and normal human prostate (PNT2) cell lines. The ferrocenyl beta-diketonate compounds are more than 18 times more cytotoxic than the ferrocenyl beta-ketoiminate analogues. Against MCF-7, compounds functionalized at the meta position are up to nine times more cytotoxic than when functionalized at the para position. The ferrocenyl beta-diketonate compounds have increased selectivity towards MCF-7 and MDA-MB-231, with several complexes having selectivity index (SI) values that are more than nine times (MCF-7) and more than six times (MDA-MB-231) that of carboplatin. The stability of these compounds in dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) has been assessed by NMR spectroscopy and mass spectrometry studies, and the compounds show no oxidation of the iron center from Fe-II to Fe-III. Cytotoxicity screening was performed in both DMSO and DMF, with no significant differences observedin their potency

    Serious Games and Soft Skills in Higher Education: A Case Study of the Design of Compete!

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    This article describes the serious game Compete!, developed within the European Erasmus+ framework, that aims to teach soft skills to higher education students in order to increase their employability. Despite the increasing relevance of soft skills for successful entry into the labour market, these are often overlooked in higher education. A participatory learning methodology based on a gamification tool has been used for this purpose. The game presents a series of scenarios describing social sustainability problems that require the application of soft skills identified as key competencies in a field study across different European countries. These competencies are creative problem-solving, effective communication, stress management, and teamwork. On completion of each game scenario and the game itself, students receive an evaluation of both their soft skills and the strategic and operational decisions they have made. In the evaluation of these decisions, both the economic and sustainability aspects of the decision are assessed. The teacher can then address the competencies and sustainability issues using the different game scenarios, thus creating higher motivation and deeper understanding amongst the students. This hybrid learning methodology incorporates digital tools for the cross-curricular teaching and learning of sustainability and soft skills. In conclusion, this article describes a possible method of incorporating soft skills in higher education; this complements students’ technical knowledge while helping to achieve Sustainable Development Goals

    Design of a Lightweight Modular Powered Transfemoral Prosthesis

    Get PDF
    Rehabilitation options for transfemoral amputees are limited, and no product today can mimic the full functionality of a human limb. Powered prosthetics have potential to close this gap but contain major drawbacks which ultimately increase the energy expenditure of the user. This thesis explores the viability of new designs and methods to reduce energy expenditure. In doing so a prototype containing many of the explored concepts is also being constructed to replace the laboratory’s current powered prosthetic, AMPRO II. This goal is accomplished by reducing weight through optimizing structural components, using lightweight motors and gearing, and reducing the energy requirements through novel passive spring sub-assemblies. Adjustable and modular components also enable a wider range of use and are explored. The main objective of this thesis is to investigate these design improvements and create the next-generation prosthetic for the Human Rehabilitation Lab. This thesis explores using a combination of passive and powered components to reduce the need for heavy actuators. Methods involve coding walking simulations based on an inverse dynamics study. By simulating design concepts with elastic elements the resulting power requirements of the motors have been estimated to evaluate each concept. Motors and gearing options have also been investigated with an optimization-based approach; gearing ratio was minimized in a test comparing discrete off-the-shelf motor options to biomechanical requirements. For the structural components, the mass of each part has been minimized through an iterative approach in FEA. Elements selected for further investigation from this thesis are being constructed with a prototype. Improvements over AMPRO II include adjustable height, functionality on both legs, a flexible foot, modularity, capabilities of passive elastic elements, and a mass estimated to be 20% lighter. Components include flat motors with harmonic drives, adjustable pylons for height, a low-profile mounting frame, passive pre-loaded springs, and a rotary series elastic actuator (RSEA). Unproven concepts such as the springs and RSEA have been designed as modular and optional to reduce risk. Moving forward, the first prototype is currently being built without the optional components to test the biomechanics. Future tests will incorporate the designed elastic elements to validate simulation concepts

    Autopet Challenge 2023: nnUNet-based whole-body 3D PET-CT Tumour Segmentation

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    Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) combined with Computed Tomography (CT) scans are critical in oncology to the identification of solid tumours and the monitoring of their progression. However, precise and consistent lesion segmentation remains challenging, as manual segmentation is time-consuming and subject to intra- and inter-observer variability. Despite their promise, automated segmentation methods often struggle with false positive segmentation of regions of healthy metabolic activity, particularly when presented with such a complex range of tumours across the whole body. In this paper, we explore the application of the nnUNet to tumour segmentation of whole-body PET-CT scans and conduct different experiments on optimal training and post-processing strategies. Our best model obtains a Dice score of 69\% and a false negative and false positive volume of 6.27 and 5.78 mL respectively, on our internal test set. This model is submitted as part of the autoPET 2023 challenge. Our code is available at: https://github.com/anissa218/autopet\_nnune

    Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon

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    This study is an investigation of the timing of extinction of late Pleistocene, large bodied mammalian herbivores (megafauna) and of the environment in which they lived. The demise of the megafauna near the end of the Pleistocene remains unexplained. Owing to potential human involvement in the extinctions, archaeologists have been particularly concerned to understand the causes for faunal losses. Our current lack of understanding of the timing and the causes of the extinctions in North America may result from a deficiency in understanding the histories of each individual species of extinct animal on a local level. Detailed regional chronologies of fauna are necessary for comparison with paleoenvironmental and archaeological data to help sort out causes for extinction. The Willamette Valley of western Oregon has long been noted for finds of megafauna, though records have not been synthesized since the early 20th century and these materials have remained largely unstudied. In this thesis, I first create a catalog of extinct megafauna recovered from the Willamette Valley. Next, using material from the northern valley, I employ AMS radiocarbon dating, stable isotope δ¹³C and δ¹⁵N analyses, and gross inferences based on the dietary specializations and habitat preferences of taxa in order to reconstruct environments and to develop a local chronology of events that is then arrayed against archaeological and paleoenvironmental data. The results of this study indicate that megafaunal populations in the northern Willamette Valley were contemporaneous with the earliest known human populations of the Pacific Northwest, as well as later populations associated with the Clovis Paleoindian Horizon. Consistent with the overkill hypothesis, radiocarbon ages span the length of the Clovis window, but no ages are younger than Clovis. Moreover, all radiocarbon ages are older than or contemporaneous to the onset of the Younger Dryas Stadial. No age ranges fall exclusively within the Younger Dryas. Comparison of megafaunal ages and paleoenvironmental records support the view that climate change contributed to local animal population declines. Prior to ~13,000 cal BP, the Willamette Valley was an open environment; herbivores mainly consumed C₃ vegetation. The timing of the loss of megafauna coincides with increased forested conditions as indicated by regional paleoenvironmental reconstruction. As the timing of megafaunal decline correlates with Clovis, the onset of the Younger Dryas, and increased forested conditions, it is not possible with the data currently available to distinguish the cause of extinction in the Willamette Valley. The age ranges of the fauna coupled with taphonomic and geologic context indicate that the fauna are autochthonous to the Willamette Valley; they do not represent ice rafted carcasses or isolated skeletal elements transported from elsewhere during late Pleistocene glacial outburst floods

    Navigating environmental constraints to injection preparation: the use of saliva and other alternatives to sterile water among unstably housed PWID in London.

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    BACKGROUND: The United Kingdom is experiencing an increase in drug-related deaths and serious bacterial infections among its most vulnerable citizens. Cuts to essential services, coupled with a growing homeless population, create a challenging environment to tackle this public health crisis. In this paper, we highlight an underexplored environmental constraint faced by people living and injecting drugs on the streets. Access to water for injection is restricted in the UK, due to legislative and financial barriers. Austerity measures, such as public toilet closures, further restrict the ability of people made homeless to access clean water and protect themselves from health harms. METHODS: We generated questionnaire (n = 455) and in-depth qualitative interview (n = 32) data with people who inject drugs in London for the Care and Prevent study. Participants provided detail on their life history; drug use, injecting and living environments; health conditions and care seeking practices. FINDINGS: A high proportion of the survey sample reported lifetime history of street homelessness (78%), bacterial infections (65%) and related hospitalisation (30%). Qualitative accounts highlight unsafe, potentially dangerous, injection practices in semi-public spaces. Multiple constraints to sourcing sterile water for injection preparation were reported. Alternatives to sterile water included puddle water, toilet cistern water, whisky, cola soda and saliva. Participants who injected heroin and crack cocaine together unanimously reported adding water at two stages during injection preparation: first, adding water as a vehicle for heroin (which was then heated); second, adding cold water to the heroin mixture prior to adding the crack cocaine. This new finding of a stage addition of solvent may represent an additional risk of infection. CONCLUSION: Currently, harm reduction equipment and resources for safe injecting are not meeting the needs of people who inject drugs who are street homeless or unstably housed. Preparation of injections with non-sterile water sources could precipitate bacterial and fungal infections, particularly when used without the application of heat. It is crucial that water for injection, also skin cleaning, is made available for the unstably housed and that harm reduction messaging is tailored to speak to the everyday realities of people who prepare and inject drugs in public spaces
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