Modeling, Analysis, Force Sensing and Control of Continuum Robots for Minimally Invasive Surgery

This dissertation describes design, modeling and application of continuum robotics for surgical applications, specifically parallel continuum robots (PCRs) and concentric tube manipulators (CTMs). The introduction of robotics into surgical applications has allowed for a greater degree of precision, less invasive access to more remote surgical sites, and user-intuitive interfaces with enhanced vision systems. The most recent developments have been in the space of continuum robots, whose exible structure create an inherent safety factor when in contact with fragile tissues. The design challenges that exist involve balancing size and strength of the manipulators, controlling the manipulators over long transmission pathways, and incorporating force sensing and feedback from the manipulators to the user. Contributions presented in this work include: (1) prototyping, design, force sensing, and force control investigations of PCRs, and (2) prototyping of a concentric tube manipulator for use in a standard colonoscope. A general kinetostatic model is presented for PCRs along with identification of multiple physical constraints encountered in design and construction. Design considerations and manipulator capabilities are examined in the form of matrix metrics and ellipsoid representations. Finally, force sensing and control are explored and experimental results are provided showing the accuracy of force estimates based on actuation force measurements and control capabilities. An overview of the design requirements, manipulator construction, analysis and experimental results are provided for a CTM used as a tool manipulator in a traditional colonoscope. Currently, tools used in colonoscopic procedures are straight and exit the front of the scope with 1 DOF of operation (jaws of a grasper, tightening of a loop, etc.). This research shows that with a CTM deployed, the dexterity of these tools can be increased dramatically, increasing accuracy of tool operation, ease of use and safety of the overall procedure. The prototype investigated in this work allows for multiple tools to be used during a single procedure. Experimental results show the feasibility and advantages of the newly-designed manipulators

Non-resident parents: why are they hard to capture in surveys and what can we do about it?

The under-representation of non-resident parents in surveys has long hindered research on family separation, leaving key evidence gaps for those making policy and practice decisions related to separating and separated families, including (but not restricted to) issues around child support, child arrangements, welfare benefits and housing. In this paper, we articulate the importance of robust quantitative data collected directly from non-resident parents. We review the methods previously employed to attempt to achieve this, and we use the UK Household Longitudinal Study (UKHLS) (University of Essex, ISER, 2017) to demonstrate where and how response biases occur. The main body of the paper reports findings from an experiment run on Wave 10 of the UKHLS Innovation Panel (Al Baghal et al., 2018; University of Essex, ISER, 2018) in which we compare two approaches to identifying non-resident parents from among the panel members. One method, a variant of that currently used in the UKHLS, asks panel members about living relatives with whom they do not live. The iv second method modifies the UKHLS standard fertility history questions collecting information on past births and then asks whether any such children are under 18 and living outside the household. Our findings are necessarily tentative, with around 100 non-resident parents identified across both arms of the experiment from among the 2,570 panel members interviewed in Wave 10. They nonetheless point towards a potential to improve the survey representativeness of non-resident parents, at least to some degree. While we found no statistically significant differences in the non-resident parent prevalence rates between the two methods, in combination they increased the non-resident parent sample by one quarter. Moreover, the data suggest that the fertility history approach improves the representativeness of the non-resident parent sample, in terms of both their socio-demographic profile and their levels of parental involvement. That said, even the combined approach results in a large underrepresentation of non-resident parents and a continued bias towards those who are more involved with their children

Building bridges? An evaluation of the costs and effectiveness of the separated parents information programme (PIP)

The Separated Parent Information Programme (PIP) is the first nationally available parent education programme for parents involved in litigation over contact and residence in England. The programme is a Contact Activity, introduced by the Children and Adoption Act 2006 as an additional tool for courts to facilitate contact. PIP is a four hour group programme for parents referred by the court. Both parties, i.e. the applicant and respondent, are required to attend the programme, but former couples attend separate groups. The groups are designed to include both men and women. The aim of the programme is to encourage parents to focus on children’s needs and perspectives. The programme is delivered by trained providers from mediation, counselling or contact services backgrounds