Simulation of cyclic reprocessing buildup on reused medical devices

Abstract

A series of discrete models were developed to study the development of cyclic reprocessing buildup (CRB) on medical devices, and to explore the effect of cleaning efficacy and type of disinfection on the removal of this CRB. A cellular automata (CA) model was used to simulate the development of CRB, including microbial replication and production of extracellular matrix (EM). The process of disinfection (microbes being killed, EM being cross-linked or oxidized, etc.) was also described in the CA model. Next, a stochastic model, Ising's model combined with Monte Carlo methods was used to simulate the removal of CRB from a surface by cleaning. These models were developed to simulate the persistent residual CRB that occurs on reused medical devices such as flexible endoscopes, to determine how well the various microbes survive in the CRB during disinfection and cleaning, and to predict the efficiency of disinfectants to kill microbes within the CRB. The CRB model will help evaluate cleaning methods to identify those that will reduce/eliminate the CRB from occurring; thereby reducing the infection transmission potential in clinical procedures involving reprocessed medical devices.