Biomedical Instrumentation and Technology最新文献

Reusable medical devices are intended to be subjected to multiple cycles of clinical processing throughout the life of the device in accordance with manufacturers' instructions for use (IFUs). IFUs should include practical information on the service life of the medical device. This laboratory-based study investigated an approach to support an indefinite lifetime for reusable devices, where the end of life depends on the visual inspection and functional verification provided in the IFU. To evaluate the design features over a broad range of surgical instruments, worst-case, representative devices were identified based on their cumulative features. The devices were subjected to repetitive cycles of processing (cleaning, disinfection, and sterilization). At different stages during the study, the devices were examined for visual effects over time. In addition, extracted levels of total organic carbon and cytotoxicity were assessed. Trend analysis over the study did not show noteworthy effects of device processing over time, including cytotoxic residuals. The results indicated that the effects of repeated cycles of processing on the device tested were negligible regarding physical damage and residual chemical levels. These findings support an indefinite device lifetime using end-of-life indications, based on the IFU and inspection requirements (for cleanliness, damage, and proper function).

Current methods for estimating average bioburden on medical device products, following ISO 11737-1:2018 with low bioburden or high limit of detection, present challenges for bioburden-based sterilization methods (e.g., radiation sterilization by ISO 11137-2:2013 or ISO 13004:2022). The inability to accurately estimate low bioburden counts per device can result in an overestimation of device bioburden and an artificially decreased challenge during validation. It can also force products to be sterilized at higher doses if the overestimation of bioburden prevents use of a lower dose than would otherwise be possible. This article describes a plate-counting technique for producing consistent and accurate estimates of low numbers of bioburden for products, even when tested as a sample item portion or with a high dilution factor relative to the average bioburden count.

In ethylene oxide (EO) sterilization processing, products can be released based on the growth responses of biological indicators or by using a parametric release (PR) process that relies on the monitoring and control of process parameters. Both methods must be used in combination with process data, in accordance with ISO 11135:2014. Process parameters can be classified as control, monitor, or both. Control parameters can be altered directly to change the readings of monitoring variables, which can't be directly controlled themselves. Currently, ISO 11135:2014 does not allow PR based on control parameters for EO concentration and humidity (calculated via pressure increment). Sterilant concentration and relative humidity (RH) can only be measured using gas analyzer probes (or similar), despite the challenges of data variance and range, calibration, redundancy, and increased sensitivity to deviations involved with use of such probes. The current article sought to experimentally determine the capacity of statistical process control to detect changes in the process, to act as an early-warning system for an out-of-specification result, and to demonstrate the use of more reliable process data for the purpose of PR. Process data from 100 routine cycles were used to trend the achieved levels of chamber RH, temperature, and EO concentration (measured by gas analyzer probes or similar), and process derived data were compared with data provided by gas analyzer probes. Process trending of routine runs was found to predict process failures, and calculating EO/water concentration via pressure increment was determined to be a viable alternative to measurement by gas analyzer probe. Further, reduced variability in key parameters enables a reduction in sterilant use.

Objectives: This study sought to investigate whether and to what extent fluid strikethrough for disposable isolation gowns is underreported and to identify areas for improving healthcare worker (HCW) understanding of gown performance. Methods: Researchers developed a confidential, qualitative, online disposable isolation gown user experience survey with an intended audience of HCWs with experience either wearing disposable isolation gowns or selecting them for purchase. The unrestricted survey link was distributed from February to March 2024. Results: A total of 211 individuals completed the survey. When asked about selection, purchasers most frequently chose to purchase level 2 isolation gowns for patient care during nonsurgical applications. More than 40% of wearers stated that they did not have a choice regarding gown protection levels when donning personal protective equipment for patient care, and 34.3% experienced fluid strikethrough (i.e., penetration of fluid through a disposable isolation gown), yet nearly one-half never reported this problem. Discussion and Conclusion: To enhance safety, the healthcare community must work together to improve guidance on gown performance and selection based on fluid exposure risk. Frequent, underreported strikethrough incidents highlighted confusion among HCWs regarding gown classification and appropriate usage. A need exists for a unified, task-based framework that clearly links gown performance with clinical risk. Fostering a culture that normalizes reporting issues-while minimizing staff burden-combined with targeted education and streamlined reporting mechanisms, will enable more informed decision making and reinforce infection prevention efforts.

End-of-life (EOL) testing requirements for reusable medical devices continue to cause confusion in the medical device industry. Regulatory expectations from U.S. and European Union authorities differ, particularly regarding whether manufacturers must conduct EOL testing or if a cautionary statement in the instructions for use is sufficient. ISO 10993-1:2021 mandates biological safety evaluations for the maximum validated number of processing cycles. Similarly, ISO 17664-1:2021, regulation (EU) 2017/745, and Food and Drug Administration guidance require manufacturers to determine whether repeated processing causes degradation that could limit a device's usable life. However, these documents provide limited direction on how to perform such assessments, leaving a gap in standardized methodology. This study aimed to develop a practical and reproducible protocol for EOL evaluation, reflecting real-world clinical use and manufacturer-recommended processing instructions. The primary objective was to assess whether biological or chemical residues remained on devices after repeated use and processing. A theoretical estimate of 100 use and processing cycles was used, representing a reasonable service life based on routine clinical conditions. A simulated 100-cycle protocol, including soiling, cleaning, and sterilization testing, revealed negligible to nondetectable residual contaminants on both surrogate coupons and actual devices. These results suggest that even under worst-case conditions, devices can be processed effectively without substantial accumulation of contaminants, supporting the selected EOL threshold. This approach offers a reproducible framework for manufacturers to evaluate and validate EOL claims, addressing a critical regulatory and practical challenge.

Healthcare staff rely on isolation gowns to provide a degree of protection against cross contamination from blood or body fluids. Gowns that meet standardized liquid barrier penetration test methods provide staff with a presumed assurance of safety. However, these test methods-namely impact penetration and resistance to hydrostatic pressure-were not drafted with personal protective equipment in mind and therefore may be inappropriate for testing products intended for use in a healthcare environment. This study found that adjusting testing parameters to better simulate clinical conditions altered the measured performance outcomes of the gowns. Specifically, increasing the temperature of the gown material's preconditioning environment or test liquid resulted in statistically significant variations in results. Further, although hydrostatic pressure resistance is measured by the appearance of a third liquid droplet on the inner surface of the gown material, the first two droplets appeared at significantly lower pressures and likely would constitute contamination of healthcare staff. The results indicated that current isolation gown test protocols and regulations should be reevaluated to more accurately reflect healthcare scenarios and improve alignment with expected barrier performance.

Currently, manufacturers of cleaning agents are not obligated to verify the efficacy of formulations used in detergents. Because of a lack of standards, companies can market cleaning agents to healthcare systems for cleaning purposes without substantiated evidence that the agents meet minimum performance criteria, as validated by medical device manufacturers. Absence of standards and regulatory oversight on the performance assessment of cleaning agents exacerbates the risk to patient safety for reusable medical devices. The aim of the current work was to develop a standard test method for reliably assessing the performance of cleaning agents. Water was used as the test method control to normalize cleaning agent performance. Cleaning agents, which were advertised as economy (i.e., minimal performance) and premium (i.e., high performance), were challenged as independent variables in the test system. Control variables were modified for each experiment to isolate the highest performing variable combination, and robustness was evaluated by performance testing at multiple independent laboratories. By controlling variables such as soil type, application, drying, and exposure time, a standardized, reproducible test method for evaluating the performance of cleaning agents used in medical device processing was developed. This approach can allow for reliable comparisons of cleaning agents to empower medical device manufacturers and healthcare facilities to make informed choices, ultimately contributing to improved patient safety through more effective cleaning validation.

Guidelines for endoscope hang time following device processing do not provide a specific time frame; instead, they recommend conducting a multidisciplinary risk assessment for any changes in protocol. After undertaking a risk assessment, a proposal to move from a 7- to 14-day hang time was developed and approved at a pediatric hospital. Rigorous protocols were put into place to assess for endoscope contamination and to surveil for endoscope-related infections. In the 3 months following the protocol change, no instances of contamination were identified and no concerns related to endoscope-related infections were noted. Implementation of the increase in scope hang time was estimated to save more than $150,000 annually in equipment and staff costs. Modifying endoscope hang time can be accomplished safely and cost effectively by adhering to strict procedures and ensuring dedicated process oversight.