title: Implantable electrode structures and their RF effects in MRI machines

authors: McCabe, Steven Owen

subjects: Deep Brain Stimulator (DBS)

abstract: Medical implants incorporating long insulated conductors can generate a serious heating hazard to a patient undergoing a Magnetic Resonance Imaging (MRI) scan. Under the high-power RF field from an MRI machine, the conductors can behave as antennas and concentrate energy into small regions of body tissue, leading to excessive joule heating. Neurostimulator implants that employ long electrode leads such as those for Deep Brain Stimulation (DBS) and Spinal Cord Stimulation (SCS), are highly susceptible to this RF hazard. Patients with these implants are generally contraindicated from MRI.

This thesis examines the heating phenomenon and identifies a variety of methods to mitigate the hazard and gain implant leads MRI safety. Techniques such as thin insulation, surface roughening, and auxiliary decoy filars are explored, with the latter shown to be especially effective at providing safety. Designs are first modelled with electromagnetic simulation software then experimentally proven inside of a gelled saline phantom within a 3T MRI machine. A lab-based measurement method is also established to enable rapid low-cost testing of prototype lead designs.

text: Implantable electrode structures and their RF effects in MRI machines Medical implants incorporating long insulated conductors can generate a serious heating hazard to a patient undergoing a Magnetic Resonance Imaging (MRI) scan. Under the high-power RF field from an MRI machine, the conductors can behave as antennas and concentrate energy into small regions of body tissue, leading to excessive joule heating. Neurostimulator implants that employ long electrode leads such as those for Deep Brain Stimulation (DBS) and Spinal Cord Stimulation (SCS), are highly susceptible to this RF hazard. Patients with these implants are generally contraindicated from MRI.

This thesis examines the heating phenomenon and identifies a variety of methods to mitigate the hazard and gain implant leads MRI safety. Techniques such as thin insulation, surface roughening, and auxiliary decoy filars are explored, with the latter shown to be especially effective at providing safety. Designs are first modelled with electromagnetic simulation software then experimentally proven inside of a gelled saline phantom within a 3T MRI machine. A lab-based measurement method is also established to enable rapid low-cost testing of prototype lead designs.

year: 2019

title: Desecuritising cybersecurity: towards a societal approach

authors: Burton, Joe

abstract: Cybersecurity is often treated as a national security issue with responses to attacks implemented by military and intelligence agencies. This has created path dependencies in which tensions between the private sector and government have continued, where over-classification of cyberthreats has occurred, and where the broader societal impacts of malicious use of the internet have been underestimated. Drawing on the societal security concept established by the Copenhagen School of International Relations, we seek to reframe cybersecurity theory and policy. In the first section of the article we establish a theoretical approach to cybersecurity that emphasises the impact of cyberattacks on society, including on the health, energy and transport sectors. The second section draws on the history of cyberconflict to assess the ways the internet has been used to exacerbate societal tensions between identity groups and to create incohesion and societal security dilemmas. This section reinterprets the way the Kosovo War, Millennium (Y2 K) Bug, 9/11 and the WannaCry incident shaped and reflected cyber policy. The final section explores how a process of cyber desecuritisation might be achieved, including through discursive change and an enhanced role for the societal sector in the event of major cyberattacks.

text: Desecuritising cybersecurity: towards a societal approach Cybersecurity is often treated as a national security issue with responses to attacks implemented by military and intelligence agencies. This has created path dependencies in which tensions between the private sector and government have continued, where over-classification of cyberthreats has occurred, and where the broader societal impacts of malicious use of the internet have been underestimated. Drawing on the societal security concept established by the Copenhagen School of International Relations, we seek to reframe cybersecurity theory and policy. In the first section of the article we establish a theoretical approach to cybersecurity that emphasises the impact of cyberattacks on society, including on the health, energy and transport sectors. The second section draws on the history of cyberconflict to assess the ways the internet has been used to exacerbate societal tensions between identity groups and to create incohesion and societal security dilemmas. This section reinterprets the way the Kosovo War, Millennium (Y2 K) Bug, 9/11 and the WannaCry incident shaped and reflected cyber policy. The final section explores how a process of cyber desecuritisation might be achieved, including through discursive change and an enhanced role for the societal sector in the event of major cyberattacks.

year: 2020

title: Mā te hangarau te oranga o te reo Māori e tautoko ai? Can technology support the long-term health of the Māori language?

authors: Mato, Paora James

subjects: Te reo Māori

abstract: Can contemporary technologies be used to support the ongoing health of an endangered language? Since the late twentieth century unprecedented and substantial social changes have been propelled by advances in contemporary technologies. Continuous connectivity harnessing digital communication, mass media and social networking has enabled instant diffusions of ideas, viewpoints and values. Unrestrained broadcasting and publishing by the general populace and the absence of the traditional media gatekeepers has been linked to the weakening of traditional cultural and linguistic ties as the private, more intimate oral domains inherent to minority indigenous cultures are being opened up to more public modes of consumption. Additionally, significant numbers of minority language speakers switch from the use of their own languages in digital environments to a language that is globally more recognisable. This type of digital language switching emulates the historical occurrence of language shift as minority language speakers opt to use a language that they perceive to be of more benefit to themselves and to their children.

Ironically, language revitalisation initiatives are embracing the ubiquitous attributes of digital technology. A joint venture between the Microsoft Corporation and the University of Waikato resulted in Māori-language interfaces for Microsoft Office and Windows. These and similar interfaces for a range of other applications were investigated. The testing groups were largely unaware the translated interfaces existed and expressed pleasure and pride to see te reo Māori within the various technologies. Following engagement the feedback was less positive. New words, unfamiliar uses of words and poor translations were cited as significant difficulties. Ensuing navigation was often hesitant and uncertain. Were the translations unsuitable? Is te reo Māori unusable within these technologies? The high incidence of task completion suggests difficulties may have arisen from a previous competence with the technologies in another language - English in this case. Future initiatives would do well to consider that perceived difficulties might arise from factors other than the design of the interfaces themselves.

 
Te reo Māori is being used on Twitter. Particular events significantly impacted the use of tweeting in te reo. During Māori Language Week the number of tweeters increased. During the Matatini Festival the volume of tweets increased. While creating an online Māori-language community, a range of strategies became necessary to maintain and prolong some conversations. At times, bilingual tweets extended faltering conversations. Sometimes forwarding tweets drew success. Furthermore, a significant number of people preferred to watch without engaging directly – perhaps a target area for future strategies.

Te reo Māori is a viable option within various technologies as evidenced by the increasing use of the language on a range of contemporary platforms. Translated interfaces provide opportunities for language promotion and extensive language visibility. The development of an online language forum has shown that conversations in te reo Māori can be successfully fostered using social media. Understanding the differences between the static visibility of translated interfaces and the dynamic nature of online conversations can be a huge asset for language strategies once issues of awareness, perception and extended engagement are successfully addressed.

text: Mā te hangarau te oranga o te reo Māori e tautoko ai? Can technology support the long-term health of the Māori language? Can contemporary technologies be used to support the ongoing health of an endangered language? Since the late twentieth century unprecedented and substantial social changes have been propelled by advances in contemporary technologies. Continuous connectivity harnessing digital communication, mass media and social networking has enabled instant diffusions of ideas, viewpoints and values. Unrestrained broadcasting and publishing by the general populace and the absence of the traditional media gatekeepers has been linked to the weakening of traditional cultural and linguistic ties as the private, more intimate oral domains inherent to minority indigenous cultures are being opened up to more public modes of consumption. Additionally, significant numbers of minority language speakers switch from the use of their own languages in digital environments to a language that is globally more recognisable. This type of digital language switching emulates the historical occurrence of language shift as minority language speakers opt to use a language that they perceive to be of more benefit to themselves and to their children.

Ironically, language revitalisation initiatives are embracing the ubiquitous attributes of digital technology. A joint venture between the Microsoft Corporation and the University of Waikato resulted in Māori-language interfaces for Microsoft Office and Windows. These and similar interfaces for a range of other applications were investigated. The testing groups were largely unaware the translated interfaces existed and expressed pleasure and pride to see te reo Māori within the various technologies. Following engagement the feedback was less positive. New words, unfamiliar uses of words and poor translations were cited as significant difficulties. Ensuing navigation was often hesitant and uncertain. Were the translations unsuitable? Is te reo Māori unusable within these technologies? The high incidence of task completion suggests difficulties may have arisen from a previous competence with the technologies in another language - English in this case. Future initiatives would do well to consider that perceived difficulties might arise from factors other than the design of the interfaces themselves.

 
Te reo Māori is being used on Twitter. Particular events significantly impacted the use of tweeting in te reo. During Māori Language Week the number of tweeters increased. During the Matatini Festival the volume of tweets increased. While creating an online Māori-language community, a range of strategies became necessary to maintain and prolong some conversations. At times, bilingual tweets extended faltering conversations. Sometimes forwarding tweets drew success. Furthermore, a significant number of people preferred to watch without engaging directly – perhaps a target area for future strategies.

Te reo Māori is a viable option within various technologies as evidenced by the increasing use of the language on a range of contemporary platforms. Translated interfaces provide opportunities for language promotion and extensive language visibility. The development of an online language forum has shown that conversations in te reo Māori can be successfully fostered using social media. Understanding the differences between the static visibility of translated interfaces and the dynamic nature of online conversations can be a huge asset for language strategies once issues of awareness, perception and extended engagement are successfully addressed.

year: 2018