Browsing by Subject "Usability"

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    Development and usability testing of a Web-based decision aid for families of patients receiving prolonged mechanical ventilation.
    (Ann Intensive Care, 2015) Cox, Christopher E; Wysham, Nicholas G; Walton, Brenda; Jones, Derek; Cass, Brian; Tobin, Maria; Jonsson, Mattias; Kahn, Jeremy M; White, Douglas B; Hough, Catherine L; Lewis, Carmen L; Carson, Shannon S
    BACKGROUND: Web-based decision aids are increasingly important in medical research and clinical care. However, few have been studied in an intensive care unit setting. The objectives of this study were to develop a Web-based decision aid for family members of patients receiving prolonged mechanical ventilation and to evaluate its usability and acceptability. METHODS: Using an iterative process involving 48 critical illness survivors, family surrogate decision makers, and intensivists, we developed a Web-based decision aid addressing goals of care preferences for surrogate decision makers of patients with prolonged mechanical ventilation that could be either administered by study staff or completed independently by family members (Development Phase). After piloting the decision aid among 13 surrogate decision makers and seven intensivists, we assessed the decision aid's usability in the Evaluation Phase among a cohort of 30 surrogate decision makers using the Systems Usability Scale (SUS). Acceptability was assessed using measures of satisfaction and preference for electronic Collaborative Decision Support (eCODES) versus the original printed decision aid. RESULTS: The final decision aid, termed 'electronic Collaborative Decision Support', provides a framework for shared decision making, elicits relevant values and preferences, incorporates clinical data to personalize prognostic estimates generated from the ProVent prediction model, generates a printable document summarizing the user's interaction with the decision aid, and can digitally archive each user session. Usability was excellent (mean SUS, 80 ± 10) overall, but lower among those 56 years and older (73 ± 7) versus those who were younger (84 ± 9); p = 0.03. A total of 93% of users reported a preference for electronic versus printed versions. CONCLUSIONS: The Web-based decision aid for ICU surrogate decision makers can facilitate highly individualized information sharing with excellent usability and acceptability. Decision aids that employ an electronic format such as eCODES represent a strategy that could enhance patient-clinician collaboration and decision making quality in intensive care.
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    ItemOpen Access
    Improving Network Security with Low-Cost and Easy-to-Adopt Solutions
    (2020) Zheng, Shengbao

    Security is always a big concern. According to the statistics, there are over 80,000 cyberattacks per day or over 30 million attacks per year. To make the Internet safe, both the industry and academia propose many solutions. However, these security solutions mainly concentrate on being effective, and ignore the other two features: deployment cost and usability. Therefore, though many works have been proposed to improve security, attacks still happen frequently.

    Our goal is to improve network security with low-cost and easy-to-adopt solutions. In this thesis, we choose Distributed Denial-of-Services (DDoS) attack and I/O path malware attack as two representatives. Fueled by IoT botnets and DDoS-for-Hire services, DDoS attacks have reached a record high volume, and launching such attacks is increasingly easy and cheap. We speculate the main reasons why existing solutions still leave DDoS as the top threat are 1) Commercial DDoS protection services are costly. 2) Solutions that require upgrading the core Internet architecture turned out to be extremely difficult to deploy. Similarly, modern operating systems enable user-level malware to log a user's keystrokes or scrape a user's screen output, which usually contains user sensitive data. Solutions with trusted hardware, virtual machines, and mobile phone facilitation all have high costs of deployment and usability for non-expert users.

    In this thesis, we present our low-cost and easy-to-adopt solutions to these two attacks. Specifically, 1) Dynashield, an on-demand DDoS defense architecture built on top of different cloud services. Dynashield introduces lower financial cost than Protection-as-a-Service product like Cloudflare, and is easier to adopt than network architecture based solutions. 2) Switchman, a framework to protect a user's I/O paths against user-level malware attacks stealing sensitive privacy data. Switchman helps non-expert users protect their sensitive data. It is easier to adopt than trusted hardware solutions like Intel SGX, and has higher usability compared to VM and additional devices based solutions.