Development of a hybrid assist-as-need hand exoskeleton for stroke rehabilitation.

Stroke is one of the leading causes of disability globally and can significantly impair a patient’s ability to function on a daily basis. Through physical rehabilitative measures a patient may regain a level of functional independence. However, required therapy dosages are often not met. Rehabilitation is typically implemented through manual one-to-one assistance with a physiotherapist, which quickly becomes labour intensive and costly. Hybrid application of functional electrical stimulation (FES) and robotic support can access the physiological benefits of direct muscle activation while providing controlled and repeatable motion assistance. Furthermore, patient engagement can be heightened through the integration of a volitional intent measure, such as electromyography (EMG). Current hybrid hand-exoskeletons have demonstrated that a balanced hybrid support profile can alleviate FES intensity and motor torque requirements, whilst improving reference tracking errors. However, these support profiles remain fixed and patient fatigue is not addressed. The aim of this thesis was to develop a proof-of-concept assist-as-need hybrid exoskeleton for post-stroke hand rehabilitation, with fatigue monitoring to guide the balance of support modalities. The device required the development and integration of a constant current (CC) stimulator, stimulus-resistant EMG device, and hand-exoskeleton. The hand exoskeleton in this work was formed from a parametric Watt I linkage model that adapts to different finger sizes. Each linkage was optimised with respect to angular precision and compactness using Differential Evolution (DE). The exoskeleton’s output trajectory was shown to be sensitive to parameter variation, potentially caused by finger measurement error and shifts in coupler placement. However, in a set of cylindrical grasping trials it was observed that a range of movement strategies could be employed towards a successful grasp. As there are many possible trajectories that result in a successful grasp, it was deduced that the exoskeleton can still provide functional assistance despite its sensitivity to parameter variation. The CC stimulator developed in this work has a part cost of USD $145 and allows flexible adjustment of waveform parameters through an on-board micro-controller. The device is designed to output current up to ±30mA given a voltage compliance of ±50V. When applied across a 2kΩ load, the device exhibited a linear output transfer function, with a maximum ramp tracking error of 5 The stimulus-resistant EMG device builds on current designs by using a novel Schmitt trigger based artefact detection channel to adaptively blank stimulation artefacts without stimulator synchronisation. The design has a part cost of USD$150 and has been made open-source. The device demonstrated its ability to record EMG over its predominant energy spectrum during stimulation, through the stimulation electrodes or through separate electrodes. Pearson’s correlation coefficients greater than 0.84 were identified be- tween the normalised spectra of volitional EMG (vEMG) estimates during stimulation and of stimulation-free EMG recordings. This spectral similarity permits future research into applications such as spectral-based monitoring of fatigue and muscle coherence, posing an advantage over current same-electrode stimulation and recording systems, which can- not sample the lower end of the EMG spectrum due to elevated high-pass filter cut-off frequencies. The stimulus-resistant EMG device was used to investigate elicited EMG (eEMG)-based fatigue metrics during vEMG-controlled stimulation and hybrid support profiles. During intermittent vEMG-controlled stimulation, the eEMG peak-to-peak amplitude (PTP) index was the median frequency (MDF) had a negative correlation for all subjects with R > 0:62 during stimulation-induced wrist flexion and R > 0:55 during stimulation-induced finger flexion. During hybrid FES-robotic support trials, a 40% reduction in stimulus intensity resulted in an average 21% reduction in MDF gradient magnitudes. This reflects lower levels of fatigue during the hybrid support profile and indicates that the MDF gradient can provide useful information on the progression of muscle fatigue. A hybrid exoskeleton system was formed through the integration of the CC stimulator, stimulus-resistant EMG device, and the hand exoskeleton developed in this work. The system provided assist-as-need functional grasp assistance through stimulation and robotic components, governed by the user’s vEMG. The hybrid support profile demonstrated consistent motion assistance with lowered stimulation intensities, which in-turn lowered the subjects’ perceived levels of fatigue

Convergence of marine megafauna movement patterns in coastal and open oceans

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 115 (2018): 3072-3077, doi:10.1073/pnas.1716137115.The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals’ movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyse a global dataset of 2.8 million locations from > 2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared to more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal micro-habitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise and declining oxygen content.Workshops funding granted by the UWA Oceans Institute, AIMS, and KAUST. AMMS was supported by an ARC Grant DE170100841 and an IOMRC (UWA, AIMS, CSIRO) fellowship; JPR by MEDC (FPU program, Spain); DWS by UK NERC and Save Our Seas Foundation; NQ by FCT (Portugal); MMCM by a CAPES fellowship (Ministry of Education)

Promoting values in the European Union’s free trade agreements: institutional competition in negotiations with Canada and Singapore

© 2016 Dr Lachlan de Lacy McKenzieThis thesis explores how competition among EU institutions shapes the promotion of its values-based foreign policy interests through trade negotiations. It argues that the EU’s human rights and sustainable development values are in tension with commercial interests in trade policy. These tensions are explored through an analysis of decision-making processes among EU institutions during FTA negotiations with Canada and Singapore. Throughout decision-making in these negotiations, institutional competition has diminished the EU’s coherence in advancing values-based foreign policy interests

Overlapping negotiations, conflicting interests? : EU-Singapore negotiations

In 2013, the European Union (EU) concluded its first comprehensive trade agreement with a Southeast Asian partner. The EU-Singapore agreement (EUSFTA) was meant as a blueprint for further negotiations in the region and indeed it was paralleled by trade talks between the EU and other members of the Association of Southeast Asian Nations (ASEAN). Given the significant challenges and roadblocks the EU faced in concluding both inter-regional and bilateral trade deals in Asia prior to the EUSFTA, the conclusion of this agreement can be understood as a significant success. However, this success has come at the cost of a shift in EU external relations away from the promotion of its own foundation norms of human rights, rule of law and democracy. This shift has had a deleterious effect on the EU’s legitimacy, founded on upholding these norms, both internally and in the Asian region. As a blueprint agreement, the EUSFTA can be analyzed to understand how this shift in the EU’s external relations will shape the EU’s wider trade policy in East Asia as well as the future of EU-Asia trade relations. This working paper will explore these negotiations and argue that the EU unbundled trade policy from its rights-based foreign policy in the EUSFTA. We argue that this creates significant opportunity for Singapore and other Asian states, but also presents a critical risk to the EU’s foundation norms, which were compromised in the EU’s negotiation of the EUSFTA.This research has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 770680, RESPECT project

The paradox of human rights conditionality in EU trade policy: when strategic interests drive policy outcomes

Increasingly, trade agendas are expanding to include non-commercial objectives such as the promotion of fundamental political and human rights. Although the European Parliament (EP) positions itself as an advocate of such objectives in the conclusion of European Union (EU) trade agreements, it rarely insists on them in negotiations. Yet, in the negotiations with Canada, the EP successfully took a tough stance on a human rights conditionality clause. Why did the EP invest political resources in insisting on conditionality in the agreement with Canada – a country which is among the top five regarding fundamental rights? We argue that, due to limited organizational capacity, composite actors, such as the EP, have to select ‘strategic issues’ among political events that make them appear as unique supporters of public interest. In this context, composite actors factor in saliency in their utility calculation of investing political resources in a policy issue.© 2018 The Author(s