Simulation based design of an UVC-LED emitter for disinfection of high-touch environmental surfaces

Healthcare-associated infections (HAIs) are a serious problem. Many studies showed that high-touch environmental surfaces can take part in the transmission of HAIs. Helping to reduce these transmissions an UVC-LED emitter is developed, which can be carried by an autonomous robotic platform. It can disinfect environmental surfaces within a clinical environment with UV-C light. The performance of the device was experimentally tested with two pathogens Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) spores. A 3-5 log reduction can be achieved within 4 s irradiation time. Further investigations are made by simulation typical environmental surfaces. In this study we aim on the disinfection of contamination hotspots like light switches and door handles. On the light switch surface it can reach a dose of almost $400\mathrm{J}/ \mathrm{m}^{2}$ within 4 s. The door handle is more challenging due to its geometry. To improve the irradiation of the backside a foil of sintered PTFE can be attached to the door surface to increase the reflectivity. With the PTFE attached a 3-4 log reduction can be achieved for E. coli and B. subtilis spores.