Author: Michael Smith
Smith, Michael, 2016 Dialysis technology in Australian Aboriginal Desert Communities, Flinders University, School of Computer Science, Engineering and Mathematics
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A brief analysis of the provision of dialysis services in Australian Aboriginal desert communities showed that improvements in dialysis system design may provide greater opportunity for return-to-country for Aboriginal patients. The need for a robust, desert-suitable dialysis system with greater water and energy efficiency than existing reverse-osmosis (RO) based systems was identified. Forward-osmosis (FO) based innovations were considered for this application due to their inherent advantages in water and energy efficiency. The use of standard, spiral-wound RO membrane elements for FO was also explored, due to their proven suitability to desert conditions. The need to evaluate any design changes in terms of their impacts on remote Aboriginal dialysis services and their communities in a culturally safe way was also identified.
A theoretical analysis of a suitable FO membrane process was completed by developing a one-dimensional analytical model. The process was based on the use of dialysate concentrate as a draw-solution and groundwater as a feed-solution. Approximations were made for external and internal membrane polarisation. Theoretical predictions were used to design and experimentally validate various strategies for controlling the output fluid concentration and flow-rate to meet the requirements for a typical medical treatment. Batch-mode production was found to be the most simple and efficient method in terms of total dialysate volume production.
Due to the use of RO elements in the design, the need for the backwashing of accumulated salt from the feed-side of the membrane was identified. This was accomplished by an extended application of osmotic backwashing, which was optimised by computational modelling and experimental analysis. It was found that the backwashing process was relatively slow, yet was a major determinant of the apparent dialysate output flow-rate of the process.
Experiments and analysis showed that there was little to be gained in terms of water efficiency by the use of this FO-based design when compared with an RO-based equivalent. Instead, a significant gain in energy efficiency was found for the FO-based design, but at the cost of an increase in system size due to the need for extra membrane area.
A culturally-safe methodology was developed for the evaluation of these design changes in the context of Aboriginal desert communities. Increases in system energy efficiency and size were passed to a qualitative reasoning and modelling (QRM) engine, the model for which was developed from a brief and purposive ethnography of the remote context. It was found that the advantages of increased energy efficiency were likely to be small compared with the disadvantages associated with any loss of working space due to increased dialysis system size.
Keywords: dialysis, forward-osmosis, dialysate, qualitative reasoning and modelling, qualitative research, design, aboriginal, desert, community
Subject: Medical Biotechnology thesis, Engineering thesis
Thesis type: Doctor of Philosophy
Completed: 2016
School: School of Computer Science, Engineering and Mathematics
Supervisor: Professor Karen Reynolds