title: A preliminary evaluation of a reusable digital sterilization indicator prototype.
abstract: BACKGROUND
  Sterilization of critical and semicritical instruments used in patient care must undergo a terminal process of sterilization. Use of chemical and physical indicators are important in providing information on the sterilizer's performance during each cycle. Regular and periodic monitoring of sterilizers using biological indicators is necessary in periodically validating performance of sterilizers. Data loggers or independent digital parametric indicators are innovative devices that provide more information than various classes chemical indicators. In this study we evaluated a prototype of an independent digital parametric indicator's use in autoclaves.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the performance of an independent digital indicator/data logger prototype (DS1922F) that could be used for multiple cycles within an autoclave.MG Materials and methods: Three batches of the DS1922F (150 samples) were used in this study that was conducted in a series. The first batch was challenged with 300 sterilization cycles within an autoclave and the data loggers evaluated to study failures and the reason for failure, make corrections and improve the prototype design. After changes made based on studying the first batch, the second batch of the prototype (150 samples) were challenged once again with 300 sterilization cycles within an autoclave and failure studied again in further improvement of the prototype. The final batch (3rd batch) of the prototype (150 samples) was challenged again but with 600 cycles to see how long they would last. Kaplan-Meier survival analysis analyses of all three batches was conducted (α = 0.05) and failed samples qualitatively studied in understanding the variables involved in the failure of the prototype, and in improving quality.
  
  
  RESULTS
  Each tested batch provided crucial information on device failure and helped in improvement of the prototype. Mean lifetime survival of the final batch (Batch 3) of prototype was 498 (480, 516) sterilization cycles in an autoclave.
  
  
  CONCLUSIONS
  In this study, the final batch of the DS1922F prototype data logger was found to be robust in withstanding the challenge of 600 autoclave cycles, with a mean lifetime of more than 450 cycles, multiple times more than prescribed number of cycles.
  
  
  CONCLUSIONS
  Instrument reprocessing is among the important aspects of infection control. While stringent procedures are followed in instrument reprocessing within the clinic in assuring patient safety, regular use of sterilization process indicators and periodic biological validation of the sterilizer's performance is necessary. Chemical indicators for use in Autoclaves provide information on whether the particular cycle's parameters were achieved but do not provide at what specific point in time or temperature the failure occurred. Data loggers and associated reader software as the tested prototype in this evaluation (DS1922F), are designed to provide continuous information on time and temperature of the prescribed cycle. Data loggers provide immediate information on the process as opposed to Biological Indicators that take from days to a week in obtaining a confirmatory result. Further, many countries do not have the sterilization monitoring service infrastructure to meet the demands of the end users. In the absence of sterilization monitoring services, use of digital data loggers for each sterilization cycle is more pragmatic.
authors.affiliation: Consultant and Professor, Consultant to Maxim Integrated through OSHA4Dental Inc. Plano Texas; and Professor, Texas A&M University Baylor College of Dentistry, Dallas, Texas, USA, e-mail: drputtaiah@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Puttaiah
authors.affiliation: Chair, Associated Dean and Professor, Chair of Department of Biomedical Materials Sciences; Associate Dean of Research, School of Dentistry; Department of Orthopedic; and Professor of Surgery and Rehabilitation Mississippi State University Jackson, Mississippi, USA.
authors.forename: J
authors.initials: J
authors.lastname: Griggs
authors.affiliation: Associate Business Manager, Industrial and Medical Solutions, Maxim Integrated, Dallas Texas, USA.
authors.forename: M
authors.initials: M
authors.lastname: D'Onofrio
mesh_terms: D000068598:Data Accuracy; D055615:Electrical Equipment and Supplies; D004866:Equipment Contamination / Q000517:prevention & control; D004867:Equipment Design; D004868:Equipment Failure; D006358:Hot Temperature; D006801:Humans; D007202:Indicators and Reagents; D008422:Materials Testing; D011786:Quality Control; D012984:Software; D013242:Sterilization / Q000295:instrumentation / Q000592:standards*; D013997:Time Factors
chemical_list: D007202:Indicators and Reagents