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Enhancing Functional Electrical Stimulation through Muscle Fatigue Tracking using an Implantable SoC
No full textFunctional Electrical Stimulation (FES) has been widely adopted in motor recovery after stroke because of its proven effectiveness in helping patients recover from foot drop and muscle weakness in clinical practice. Nevertheless, conventional transcutaneous FES can rapidly cause muscle fatigue due to its reverse recruitment principle and large stimulation area. The voluntary force of muscle drops dramatically when fatigued. Consequently, the effectiveness of FES rehabilitation is greatly limited by premature and unmonitored muscle fatigue. This research explores a possible fatigue-delayed implantable FES system and the techniques required by this stimulation platform.A Muscle Fatigue Status (MFS)-controlled FES system and a dynamic stimulation controlling strategy are proposed in Chapter 3. This system will be expected to use MFS to control the operation of the developed implantable stimulator. The challenges of muscle fatigue extraction, the implementation of the stimulator and the design of low-power bio-signal acquisition are addressed in this thesis.Under electrical stimulation, recorded mixed signals contain stimulus – that is, evoked electromyography and stochastic electromyography (EMG). Muscle fatigue features cannot be extracted from such signals. To investigate an effective fatigue-tracking algorithm, a discrete wavelet transform (DWT) denoising artefact removal technique was used during the signal separation process. The M-waves were extracted from the evoked EMG signals and the stochastic EMG. The median frequencies (MDF) were only calculated from the power spectrum of stochastic EMG signals. Muscle fatigue was determined when the M-waves’ peak to peak value and the EMG’s MDF slopes crossed zero with an accuracy of 93% achieved.A microstimulator system was designed, fabricated, and tested by using system on chip (SoC) technology. The SoC consists of a Finite State Machine (FSM)-based controlling mechanism, a high-resolution current steering digital to analogue converter (DAC) and a low-power binary phase shift keying (BPSK) demodulator. This designed device operates on a 1.8V power supply and has 0.12 mW power consumption with a size of 1.5 mm2, making it appropriate for implantation.In addition, a low-power switched opamp (SO)-based switched capacitor (SC) biquad circuit is proposed for the low-power EMG acquisition system. Using this innovative design, a simulated 135 uW power consumption of the EMG analogue filter has been achieved. A low-power EMG monitoring system can be implemented by using this filter with pre-amplifier and analogue to digital convertor .The major finding of this research is that muscle fatigue features can be extracted during stimulation and muscle training, by using the novel muscle fatigue tracking method. Moreover, an initial prototype of implantable stimulators (SoC) with the correct function was designed and tested. The former improved the feasibility of using fatigue levels to control the stimulator in real-time. The latter is a challenging but essential component of the whole system. These two investigations exhibit potential for the implementation MFS-controlled FES systems, which is expected to enhance the efficacy and reliability of FES-based muscle rehabilitation.</p
Dose Verification in Tissue Equivalent Media for Lung and Spine Stereotactic Body Radiotherapy
No full textRadiation Therapy is common cancer treatment modality which aims to kill tumour cells whilst minimising damage to adjacent healthy tissue. Stereotactic Body Radiation Therapy (SBRT) refers to a treatment delivery technique which delivers a heterogenous dose distribution to tumours in a range of body sites with extreme geometric precision. SBRT often targets small, isolated lesions in the lymph nodes, lung, spine, bone, liver, kidney and adrenals. SBRT leverages improvements in technology such as Image Guided Radiotherapy (IGRT), six degrees of freedom (6DoF) couch corrections, improved mechanical performance of delivery machines and intrafraction monitoring to allow a reduction of margin sizes, typically 1mm – 1cm depending on tumour site. SBRT fractionation schemes vary across clinical indications and radiation oncologists, but typically remain between 1-8# [1]. The combination of reduced margins, short fractionation and increased dose inhomogeneity across target volumes make the delivery high risk in terms of dosimetric and spatial accuracy. Participation in end-to-end testing and dosimetry audits is recommended in international guidelines to mitigate systemic risks that may have manifested in clinical radiotherapy facilities [1-6]. SBRT dosimetry audits have been reported for worldwide but are often confined to a credentialing activity for a specific clinical trial or are confined to a single body site. This work describes the design and implementation of an end-to-end dosimetry audit for soft tissue, spine and lung sites. The audit was designed and performed for the Australian Clinical Dosimetry Service (ACDS), at the Australian Radiation and Nuclear Safety Agency (ARPANSA). The audit utilised a personally designed, modified version of a commercially available anthropomorphic phantom equipped with a tissue equivalent body, bilateral lungs, a lung tumour and an anatomically realistic spine consisting of cortical and trabecular bone materials. The audit was performed across Australian and New Zealand radiotherapy clinics commencing April 2018 and continuing into the future. The data reported in this thesis was collected to April 2024 and included 782 plans measured on 159 treatment machines of various classes at 128 facilities. This is the most comprehensive onsite SBRT audit dataset internationally, and the only dosimetry audit which includes medium dependent corrections and testing. A key consideration of this work is the medium in which the audit measurements were conducted. Radiotherapy dose is typically defined and reported as dose to water, water being a surrogate for patient soft tissue. Radiotherapy detectors are calibrated in terms of dose to water, and international codes of practice which define dose as dose to water have been the mainstay of dosimetry for decades. As such, measurements are typically performed in water, or water equivalent plastic phantoms. Whilst such measurements are sufficient for gross checks of dose accuracy, it is desirable to measure in materials which represent intended patient targets such as bone and lung. Anatomically realistic phantoms are commercially available to more accurately reflect the treated patient, and are equipped with bone and lung equivalent plastic materials which can be used to verify dose calculation in treatment planning systems. This thesis presents a novel formalism for measuring in such materials and reporting dose to the medium in which the measurement is conducted. This is achieved through Monte Carlo simulations to define correction factors for measuring in the cortical bone, trabecular bone, lung tumour and inhale lung materials present in the CIRS SBRT phantom. The Monte Carlo simulations showed significant correction factors for the bone and lung materials; up to 12.5% and 3.4%/9.2% for bone and in-field/out of field lung respectively. Omission of such corrections would lead to large discrepancies in measured dose when comparing to planning system calculations. Application of the correction factors in the SBRT audit is discussed, and analysis of the dose to medium reported audit results is provided across a large cohort of plans. In this thesis a comprehensive SBRT dosimetry audit was developed across range of clinical cases and delivery systems. High pass rates were seen across soft tissue, spine and lung cases, indicating the safe implementation of SBRT practice in our region. Sub optimal results observed can be attributed to differences in dose calculation algorithms, dosimetric offsets and IGRT mismatches. IGRT and treatment target dose differences were the dominant sources of error accounting for 36.7% and 40.6% of failed audits respectively. Facility Patient Specific Quality Assurance results were not an indicator of audit outcome, highlighting the importance for treating facilities to participate in independent dosimetry audits.</p
Characterising Topic Familiarity and Query Specificity Using Eye-Tracking Data
No full textEye-tracking data has been shown to correlate with a user’s knowledge level and query formulation behaviour. While previous work has focused primarily on eye gaze fixations for attention analysis, often requiring additional contextual information, our study investigates the memory-related cognitive dimension by relying solely on pupil dilation and gaze velocity to infer users’ topic familiarity and query specificity without needing any contextual information. Using data collected via a lab user study ( = 18), we achieved a Macro F1 score of 71.25% for predicting topic familiarity with a Gradient Boosting classifier, and a Macro F1 score of 60.54% with a k-nearest neighbours (KNN) classifier for query specificity. Furthermore, we developed a novel annotation guideline – specifically tailored for question answering – to manually classify queries as Specific or Non-specific. This study demonstrates the feasibility of eye-tracking to better understand topic familiarity and query specificity in search.</p
The Chameleonic Governance of NGOs in Cambodia: A Story of Learning
No full textNon-government organisations (NGOs) in Cambodia operate in an environment of strategic ambiguity and are exposed to multiple threats, creating challenges for their effective governance. For Cambodian NGOs, ambiguity arises from several sources. Cambodia’s national government, notionally democratic but also kleptocratic, neo-patrimonial and dynastic, is often hostile to NGOs and inconsistent in applying the rule of law. Fickle international donors impose, among other compliance related obligations, expectations for a corporate style of NGO governance consisting of a so-called independent board representing organisational stakeholders. Local stakeholders, following notions of guanxi (social networks and relationships), harbour expectations for loyalty and mutual benefit, tending the khsae (strings) that connect people to their colleagues, families and communities. These varied expectations, and the responses of some in the non-government sector, support a case for the reimagination of received governance prescriptions and the adoption of more reflexive models. Such reimagination sensibly situates governance as both a contested normative phenomenon and a dialogic process of continual learning. This research reflects collectively and critically on the self-determination of governance practice for and by Cambodian NGOs, grounded in a thorough examination of the context for understanding and shaping governance practices used by Cambodian NGOs. In so doing, the research explores local interpretations, understandings, and practices of governance, with a view to developing more situated, culturally relevant, and useful theories and descriptions of governance practices in Cambodia. Preparatory work for the research indicated that governance practices in Cambodia are not fixed, but fluid, changing and adaptive. Accordingly, the research needed to focus on processes of learning and adaptation as much as on practices. The research was undertaken as a cooperative inquiry consistent with a participatory worldview that explicitly values emergent and developmental forms of research. Cooperative inquiry is a type of participatory, action-based research premised on learning that is at once personal, collective, transformational, looped, reflexive and often requires unlearning and relearning. It supports the professional development of co-researchers and contributes to the quality of governance practice, not merely studies and describes it. Seven Cambodian NGO leaders joined the cooperative inquiry group, and, with me, completed at least six rounds of planning, personal action and collective reflection. The research processes allowed co-researchers to develop, gradually and together, a shared understanding of governance practices in Cambodia. Recurring themes of the cooperative inquiry process include concern for capacity, imbalanced relationships of power, and a requirement for adaptation and flexibility. Analysis explored how dominant corporate constructions of governance are understood and applied by Cambodian NGO leaders; the lived experience of NGO governance for Cambodian NGO leaders; and, the localised and contextualised constructions of NGO governance that emerge, or are generated and/or described by Cambodian NGO leaders. Co-researchers describe a mode of governance, which I have dubbed chameleonic. Chameleonic governance is both outcome and process. As an outcome, chameleonic governance is here positioned as a learned behaviour and an appropriate response to strategic ambiguity. The complexities of working in competing cultural and value systems require considerable dexterity – indeed, chameleonic behaviours – on the part of Cambodian NGO actors. Processually, chameleonic governance shifts according to its context and is situated as a dialogic process of continual learning. Dialogic and relational interpretations of NGO governance, informed by complexity and contingency theories, were developed through and situated in collaborative processes.Using a scrappy, but grounded means of ‘just doing it’, co-researchers seek to explore and establish what may work for them, through continual attentiveness to their environment. They are constantly listening, learning and readying themselves for response. This involves clarifying and reclarifying roles and responsibilities, managing complex power relations and hierarchies, prioritising mutuality, and expanding capacity. Co-researchers mull together about how best to present a ‘face’ or narrative that is judged likely to be acceptable to the most powerful stakeholders, recognising that who is most powerful is subject to change in any given moment. Blending in, hiding, or even obfuscating, if need be, are viable options, in the interests of survival and adaptation to the requirements of powerful actors. The lived experience of co-researchers reveals that NGO governance is generally the responsibility of the director, ideally with support from a board. A key contributor to the effectiveness of NGO governance mechanisms is the director’s magnanimous schemata: The director should be humble enough to work in partnership with others, seek advice and learn, and be satisfied with his or her lot in life, such that he/she does not prioritise personal enrichment. The concept of chameleonic governance advanced here offers a useful narrative for understanding the shifting system behaviour, limited predictability and practices of emergence which, like for other complex adaptive systems, characterise Cambodian NGO governance. This thesis brings together disciplinary insights from Cambodian studies, NGO governance and action research for the first time, contributing new knowledge to each of these fields of inquiry. I advance substantive knowledge about NGO governance in Cambodia by carefully describing how governance is understood and interpreted, in context and in situ, normatively, and through lived experience. I deepen understanding of how neo-patrimonialism manifests in the case of NGO governance and leave a legacy of individuals in Cambodia familiar with and able to advocate for participatory approaches to research. I answer the call from NGO governance theorists to produce more action research, more multi-theoretical and contingency-based research, and more research focussed on the majority world. I eschew rationalist approaches, adopting a situated and dialogic approach both to governance itself and to the research designed to understand it more fully. Finally, I bring an essential learning dimension to understandings of governance as a dialogic process. Supporting praxis, the mode of chameleonic governance is presented in a form conducive to providing some explanatory power in relation to how decisions are made and authority is exercised. Importantly, this research inspired personal and organisational transformations. The personal learning experiences of co-researchers, including me, contributed to transformational changes in attitude and behaviour. This practical knowledge consummates other types of knowledge(s) produced by the research.</p
Active Ageing Through Sport: Exploring participation and identity in AFL Masters football
No full textThis research examines how AFL Masters, a modified Australian rules football competition for older adults, supports active ageing. With ageing populations facing increased health risks from sedentary lifestyles, this mixed-methods case study investigates competitive sport's role in keeping people active and socially connected as they age. The methodology adopts a national survey and focus groups involving current and lapsed AFL Masters members. Through the lens of social identity theory and WHO’s Active Ageing Policy Framework, this research aims to understand how sporting communities influence identity, belonging, and wellbeing. The study addresses how modified, high-impact sport can support active ageing, providing evidence-based recommendations for sporting organisations to enhance health outcomes and challenge conventional notions of ageing and physical activity.</p
Nature's impact: Do extreme natural disasters influence retail investors?
No full textThis study investigates the influence of extreme natural disasters on the trading behaviour of retail investors, focusing on two significant events in Australia: Cyclone Debbie in 2017 and the Black Summer bushfires in 2019–2020. Utilising a unique dataset of transaction-level trade data, we examine whether retail investors exhibit a preference for trading stocks with Environmental, Social, and Governance (ESG) ratings during these periods. The findings reveal that retail investors significantly increase their trading activities in ESG-rated stocks (especially high ratings) in the aftermath of these disasters. This behaviour suggests a heightened awareness and preference for ESG performance among retail investors when faced with catastrophic events. In contrast, institutional investors do not show similar trading patterns, indicating a divergence in investment strategies between retail and institutional investors during times of heightened market uncertainty. Despite awareness concerning ESG during natural disasters, we find that ESG stocks heavily purchased by retail investors generate negative returns in the five-day window subsequent to the natural disasters.</p
Empowering social entrepreneurial intentions through experiential learning and self-efficacy
No full textThis study examines the impact of experiential learning on social entrepreneurial intentions, refining a previous model by exploring self-efficacy as a mediating factor. Data from 437 final-year students at two Malaysian universities, where experiential learning methods such as business plan development and group work were integrated, were analyzed using PLS-SEM. Findings reveal that self-efficacy partially mediates the positive relationship between experiential learning and social entrepreneurial intentions. These insights support policymakers in embedding experiential learning within social entrepreneurship education to foster graduates' critical thinking, entrepreneurial skills, and commitment to sustainable, responsible management. The study advances theoretical discussions by extending Kolb's Experiential Learning Theory and Bandura's Social Learning Theory, particularly in non-Western contexts like Malaysia. Uniquely, it examines the interplay between experiential learning dimensions, self-efficacy, and social entrepreneurial intentions using a modified Kolb Learning Style Inventory integrated with social learning theory. This study introduces an innovative pedagogical approach integrating experiential learning, critical thinking, and sustainability into social entrepreneurship education, fostering ethical decision-making and responsible management while addressing a crucial gap in understanding how experiential learning develops socially responsible business leaders.</p
Explicit CSR Communication Among Trade and Subcontractor SMEs in the Construction Industry
No full textThis study explores the current landscape of explicit Corporate Social Responsibility (CSR) communication via webpages by Small and Medium Enterprises (SMEs) in the construction industry to their stakeholders. A qualitative content analysis, grounded in stakeholder theory, was conducted on the webpages of 67 trade and subcontractor SMEs in the construction industry, specifically in the state of Victoria, Australia. It is found that Environmental CSR practices are the most frequently disclosed, particularly regarding eco‐friendly products and packaging. Employee‐related CSR practices are second, focusing on occupational health and safety. However, disclosures on Society/Community‐ and Supplier/Partner‐related CSR practices are limited. SMEs comprise a large proportion of the construction industry, face resource constraints but are crucial for local economies and sustainable practices. Unlike most of the previous studies which focus on large enterprises, this research examines the CSR practices of construction SMEs through their webpages, offering insights into their role in socially responsible construction and the need to guide SMEs for effective communication of CSR initiatives. The focus is on the webpages of trade and subcontractor SMEs in the construction industry. The findings guide SME owner‐managers in improving CSR disclosure, emphasising the need for tailored communication strategies.</p
Integrating Sustainability in Curricula of School if Communication & Design: Towards Education for Sustainable Development
No full textThis report on the integration of Sustainable Development Goals (SDGs) within the curriculum of the School of Design and Communication at RMIT Vietnam marks a significant milestone in our journey to embed the UNSDGs in all of our programs. Our commitment to sustainable practice is central to our philosophy and reflects RMIT University's dedication to the United Nations Sustainable Development Goals. This report reveals that we have already made concerted efforts to embed environmental sustainability within our pedagogy. However, it also brings to light the imperative to intensify our focus on socio-economic objectives, ensuring a holistic approach to sustainability. The findings indicate a need for a more explicit incorporation of the SDGs across our curriculum, which we are working toward achieving within the next two years.</p
The Blockchain Treasury Governance Dilemma
No full textBlockchain treasuries are pools of cryptocurrency earmarked for funding goods and services within a blockchain ecosystem, such as protocol upgrades. Blockchain participants, such as users and developers, face a trust problem in ensuring that the treasury is robust to opportunism, such as theft or misappropriation of the assets. Treasury governance structures, such as committees or stakeholder voting, seek to create trust in treasury functions. In this paper, we use new comparative economics to examine how treasury governance mechanisms minimize the costs of dictatorship and disorder, thereby bolstering trust. We interpret case studies of innovative treasury governance within this Institutional Possibilities Frontier (IPF) framework, showing that the costs shift throughout the lifecycle of a blockchain community, and those costs are often revealed or learned through governance crises. These changes lead ecosystem participants to choose and innovate on treasury governance.</p