PhD, EngD and MSc by research theses (SATM)

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Browsing PhD, EngD and MSc by research theses (SATM) by Supervisor "Alcock, Jeffrey R."

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    Examining the use of visualisation methods for the design of interactive systems
    (Cranfield University, 2016-06) Li, Katie; Tiwari, Ashutosh; Alcock, Jeffrey R.
    Human-Computer Interaction (HCI) design has historically involved people from different fields. Designing HCI systems with people of varying background and expertise can bring different perspectives and ideas, but discipline-specific language and design methods can hinder such collaborations. The application of visualisation methods is a way to overcome these challenges, but to date selection tools tend to focus on a facet of HCI design methods and no research has been attempted to assemble a collection of HCI visualisation methods. To fill this gap, this research seeks to establish an inventory of HCI visualisation methods and identify ways of selecting amongst them. Creating the inventory of HCI methods would enable designers to discover and learn about methods that they may not have used before or be familiar with. Categorising the methods provides a structure for new and experienced designers to determine appropriate methods for their design project. The aim of this research is to support designers in the development of Human-Computer Interaction (HCI) systems through better selection and application of visualisation methods. This is achieved through four phases. In the first phase, three case studies are conducted to investigate the challenges and obstacles that influence the choice of a design approach in the development of HCI systems. The findings from the three case studies helped to form the design requirements for a visualisation methods selection and application guide. In the second phase, the Guide is developed. The third phase aims to evaluate the Guide. The Guide is employed in the development of a serious training game to demonstrate its applicability. In the fourth phase, a user study was designed to evaluate the serious training game. Through the evaluation of the serious training game, the Guide is validated. This research has contributed to the knowledge surrounding visualisation tools used in the design of interactive systems. The compilation of HCI visualisation methods establishes an inventory of methods for interaction design. The identification of Selection Approaches brings together the ways in which visualisation methods are organised and grouped. By mapping visualisation methods to Selection Approaches, this study has provided a way for practitioners to select a visualisation method to support their design practice. The development of the Selection Guide provided five filters, which helps designers to identify suitable visualisation methods based on the nature of the design challenge. The development of the Application Guide presented the methodology of each visualisation method in a consistent format. This enables the ease of method comparison and to ensure there is comprehensive information for each method. A user study showing the evaluation of a serious training game is presented. Two learning objectives were identified and mapped to Bloom’s Taxonomy to advocate an approach for like-to-like comparison with future studies.
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    Optimising oscillatory positive expiratory pressure devices for effective airway clearance
    (2016-12) Khasawneh, Mohammad; Alcock, Jeffrey R.; Tiwari, Ashutosh
    Oscillatory positive expiratory pressure (OPEP) devices are a form of airway clearance techniques that are wildly used in the clinical practice and well accepted by patients. Clinicians and respiratory therapists are responsible for choosing the appropriate OPEP device for their patients. In addition, they are responsible for optimising the mechanical behaviour of the device to achieve effective airway clearance results. The effectiveness of OPEP devices is critically dependent on the properties of the oscillatory pressure wave generated by these devices. However, the pressure wave parameters vary at different settings (flow rates and resistance levels combinations). Despite OPEP devices been around for several years and routinely used in clinical practice, the question remains as to “which settings are appropriate for optimum airway clearance results”. The mechanical behaviour of several OPEP devices has been investigated in previous studies. However, experimental set up variations makes a direct comparison between the results very difficult, especially for devices from different manufacturers. Also, previous attempts to inform the clinical practice on how to use OPEP devices were limited by the lack of technical performance criteria to guide optimising these devices according to patients underlying physiological dysfunction and airway clearance aims. The aim of this research is to characterise the optimum mechanical behaviour of OPEP devices for effective airway clearance. In this research, the mechanical behaviour of OPEP devices was characterised using a validated measurement system and a systematic experiment design that takes into account the findings and limitations of previous studies. The mechanical behaviour was mathematically modelled and validated using regression analysis techniques. Desirability optimisation function was used to characterise OPEP device settings that satisfy optimum technical performance criteria. Based on these findings, the research discussed how OPEP devices could be optimised in clinical practice for different disease groups and airway clearance therapy aims. In the field of airway clearance research, devices evaluation lies at the base of the evidence appraisal hierarchy. In this research, optimum technical performance criteria for effective airway clearance are proposed. This research offers a comprehensive characterisation of the mechanical behaviour of OPEP devices under a unified experimental setup and flow ranges commonly found in clinical practice. Also, this research provided a comprehensive characterisation of the optimum mechanical behaviour of OPEP devices for different disease groups and airway clearance therapy aims. A possible area for future work would be to investigate the pressure wave parameters effect on airway clearance from a fluid dynamic perspective.