This Thesis focuses on the evaluation and optimization of a low-temperature hydrogen peroxide sterilization system for its application in reusable medical devices with complex cavities and geometries, such as endoscopes. The main objective of the research is to evaluate the penetrability and microbicidal efficacy of the 130 HPO® (Hydrogen Peroxide) equipment manufactured by MATACHANA S.A., as well as to analyze modifications in cycle parameters to find potential process improvements. A comparative analysis was carried out between the unmodified programmes (control) and various conditions obtained by modifying certain cycle parameters. In order to evaluate possible improvements to the process, it was decided to work with cycle fractions(a quarter cycle and a half cycle), as well as with spores exhibiting a high D-value, which allows for an intermediate point to be obtained in the bacterial survival count. The tests were carried out using strips inoculated with Geobacillus stearothermophilus spores, in most cases using process challenge devices (PCDs). The results revealed a high microbicidal efficacy on surfaces, achieving complete inactivation with a single pulse. However, in cannulated structures, none of the experimental modifications (alterations in aeration, vaporizer temperature, pressures, or injections) demonstrably improved sterility or penetration capacity compared to the original factory programs. Furthermore, high microbiological variability was observed between cycles, compromising reproducibility under modified conditions. In conclusion, it is determined that the tested parametric alterations do not provide an operational or safety benefit. The original cycles configured by the manufacturer perform more efficiently and consistently, establishing themselves as the optimal and secure option for the evaluated reprocessing

El present Treball Final de Grau es centra en l'avaluació i optimització d'un sistema d'esterilització per peròxid d'hidrogen a baixa temperatura per a la seva aplicació en dispositius mèdics reutilitzables amb cavitats i geometries complexes com els endoscopis. L'objectiu principal de la investigació és avaluar la penetrabilitat i l'eficàcia microbicida de l'equip 130 HPO® (Hydrogen Peroxide) fabricat per MATACHANA S.A., així com analitzar modificacions en els paràmetres dels cicles buscant millores en el procés. Es va dur a terme una anàlisi comparativa entre els programes no modificats (control) i diverses condicions obtingudes en modificar certs paràmetres del cicle. Per tal d'avaluar possibles millores en el procés, es va decidir treballar amb fraccions de cicle (un quart de cicle i un mig cicle), així com amb espores que tenen un valor D elevat, la qual cosa permet obtenir un punt intermedi en el recompte de supervivència bacteriana. Les proves es van dur a terme utilitzant tires inoculades amb espores de Geobacillus stearothermophilus, en la majoria dels casos utilitzant dispositius de desafiament de procés (PCDs). Les proves es van dur a terme utilitzant tires inoculades amb espores de Geobacillus stearothermophilus, en la majoria dels casos utilitzant dispositius de desafiament de procés (PCDs). Els resultats van revelar una elevada eficàcia microbicida en superfícies, assolint la inactivació completa amb un únic pols. No obstant això, en estructures canulades, cap de les modificacions experimentals (alteracions en l'aireació, temperatura del vaporitzador, pressions o injecions) va millorar de forma demostrable l'esterilitat ni la capacitat de penetració respecte als programes originals de fàbrica. Així mateix, es va observar una alta variabilitat microbiològica entre cicles, fet que compromet la reproduïbilitat sota condicions modificades. En conclusió, es determina que les alteracions paramètriques assajades no aporten un benefici operatiu ni de seguretat. Els cicles originals configurats pel fabricant actuen de forma més eficient i consistent, consolidant-se com l'opció òptima i segura per al reprocessament avaluat.

This Thesis focuses on the evaluation and optimization of a low-temperature hydrogen peroxide sterilization system for its application in reusable medical devices with complex cavities and geometries, such as endoscopes. The main objective of the research is to evaluate the penetrability and microbicidal efficacy of the 130 HPO® (Hydrogen Peroxide) equipment manufactured by MATACHANA S.A., as well as to analyze modifications in cycle parameters to find potential process improvements. A comparative analysis was carried out between the unmodified programmes (control) and various conditions obtained by modifying certain cycle parameters. In order to evaluate possible improvements to the process, it was decided to work with cycle fractions(a quarter cycle and a half cycle), as well as with spores exhibiting a high D-value, which allows for an intermediate point to be obtained in the bacterial survival count. The tests were carried out using strips inoculated with Geobacillus stearothermophilus spores, in most cases using process challenge devices (PCDs). The results revealed a high microbicidal efficacy on surfaces, achieving complete inactivation with a single pulse. However, in cannulated structures, none of the experimental modifications (alterations in aeration, vaporizer temperature, pressures, or injections) demonstrably improved sterility or penetration capacity compared to the original factory programs. Furthermore, high microbiological variability was observed between cycles, compromising reproducibility under modified conditions. In conclusion, it is determined that the tested parametric alterations do not provide an operational or safety benefit. The original cycles configured by the manufacturer perform more efficiently and consistently, establishing themselves as the optimal and secure option for the evaluated reprocessing