Water efficient sterilization for humanitarian aid

Abstract

This master thesis describes a graduation project that is elaborated for Médecins Sans Frontières (MSF) innovation project Sweden. MSF is an independent, international, medical humanitarian organization. The organization is specialized in providing humanitarian aid in (developing) countries. The goal of this project is to find a solution for the problems that occur during the sterilization processes of MSF in the context of humanitarian aid. Currently MSF uses the Robustex 90L autoclave to sterilize their instruments, however MSF is interested in a redesign or an improved version of the Robustex. Sterilization is the process that kills and removes micro-organisms from medical devices and is one of the most important contamination prevention steps in a hospital. Two sterilization departments, in the Netherlands, were visited to understand the sterilization process in developed countries. To understand the habits, needs and problems of the sterilization process and the staff of MSF. This project includes a research in which insiders from the organization are interviewed and product tests are done with the Robustex at the MSF training centre in Brussels. Next to MSF, the research phase includes insights from International Committee of the Red Cross (ICRC) and Ministries of Health (MoH) from developing countries. This is done to enlarge the market for manufacturers of autoclaves. MSF purchases around 10 autoclaves a year, which an insufficient amount for manufacturers to make a profit off. These stakeholders all faces problems such as lack of resources (water, energy and sterilization knowledge) and poor maintenance capabilities. The results of the research show large differences in product requirements between MSF, ICRC and the MoH. MSF requires a robust autoclave with electrical functionalities such as a vacuum pump. ICRC requires a smaller autoclave with the ability to monitor the conditions inside the sterilization chamber during a cycle to validate the quality of the sterilized packages. And the MoH requires a larger autoclave as basic as possible with an easy control system. A product that fits all these requirements would be unrealistic, extremely expensive and completely unusable. Therefore this project focussed on the requirements that all stakeholders have in common, which is a water, energy and time efficient autoclave which is still easy to operate and is low in production cost. The design leaves the option open to improve the quality of sterilization by implementing add-ons such as the vacuum pump and condition monitor, nevertheless these electrical improvements will only work in conditions were all resources are available, which is seldom the case. In conclusion, this project successfully demonstrates a robust autoclave by separating the heating space from the sterilization chamber. The redesign consumes 75% less water, 23 - 38% less time and 30-50% less energy during a sterilization cycle. The production costs will be approximately €450 more than the Robustex. The operation costs however, will decrease with €3 per cycle, which is estimated to be €1000 per year. The increase in the amount of control valves is concerning, since uneducated people in emergency relief areas will use the product. The technical feasibility is validated with a thermodynamic study and the manufacturability has been confirmed by autoclave and engineering companies. The usability is tested with a full-scale mock-up and Dutch adult participants. More valuable tests should be done with real life tests in emergency settings, to evaluate local behaviour concerning the autoclave control.