Biomedical Instrumentation and Technology最新文献

The AAMI working group ST/WG 93 is finalizing a standard (AAMI ST98) for the cleaning validation of reusable medical devices based on guidance from the technical information report AAMI TIR30:2011/(R)2016. A number of analytical best practices are being considered for this new standard. Test method suitability for processing cleaning validations historically has been established using one positive control and performing an extraction efficiency. The new cleaning validation standard is proposed to require a change from only one replicate test sample to three when performing method suitability. This change will affect manufacturers; therefore, the value of and consideration for performing these additional replicates requires explanation. This article discusses how variation of validation parameters can affect the accuracy and precision during method suitability testing. Multiple replicates are needed to understand the variability of method extraction and impact on cleaning validations of reusable medical devices.

The ethylene oxide (EO) product test of sterility (ToS) can be conducted to comply with ANSI/AAMI/ISO 11135:2014 for the generation of data to demonstrate the appropriateness of the biological indicator (BI) that is used to develop and qualify the EO sterilization process. Clause D.8.6 of 11135 provides an option to perform a sublethal EO process, followed by conducting a product ToS, performing sterility testing of BIs from the process challenge device, and comparing the test results. Certain limitations for the EO product ToS should be considered when conducting studies that feature the use of this test, in order to support compliance with this requirement. Limitations for any sterility test include sample size, testing frequency, detection sensitivity, and/or the potential for false-positive/false-negative results, each of which must be recognized and well understood in order to support compliance with the standard. In addition, the experimental design of any study featuring the use of a sterility test should be carefully developed to ensure the generation of scientifically sound results and conclusions to support the study objective.

In 2015, the Food and Drug Administration (FDA) updated its guidance on test methods for cleaning validations for reusable medical devices. The changes include the condition and contamination of devices, test samples and controls, cleaning process performed during validation, extraction methods, and endpoints. This article reviews the FDA's changes to cleaning validations. Examples are presented using flexible endoscopes in order to provide a practical guide to performing cleaning validations.

In 2013, Sterigenics undertook the addition of a 10-MeV electron beam (e-beam) accelerator at its facility in Jarinu, Brazil. A gamma irradiator was already located at this facility, which processed materials and provided irradiation services in Brazil. The decision to implement an e-beam accelerator at the same facility was made in order to diversify the technology that could be offered and to rapidly increase the overall capacity of the facility. In addition, the e-beam technology was complementary to the existing gamma pallet irradiator and thus provided an internal backup for some processes. The main challenge for staff at the Brazil facility was cross-validating processes carried out by the existing gamma irradiator with processes performed with the new e-beam accelerator. The overall success rate in the cross-validation of processes between the two modalities was positive. Products for healthcare, laboratory testing, and other low-bulk-density products that basically consisted of commonly used polymeric materials were most suitable for cross-validation. Products of higher bulk density, greater heterogeneity, or variability between packaging systems and products with dose specifications for a tote rather than a pallet gamma irradiator presented limitations in the cross-validation success rate. This article focuses on the transition approach, discusses the types of products that were successfully cross-validated in e-beam from gamma, and presents examples where such cross-validation was not pursued.

When investing in X-ray irradiation facilities around the world, an opportunity exists for defining a regulatory framework for assessing the transition from current gamma irradiation processes. Historically, regulatory strategies for changing the radiation source for routine processing has consisted of repeating the majority, if not all, of the validation activities performed as part of an initial validation and associated submission. Although not a new concept, performing a risk assessment has the potential to be leveraged more fully by increasing the rigor of determining what is changing when product moves from a gamma to an X-ray irradiator, then determining how these differences may affect product characteristics. During these steps, differences can be identified and quantified between radiation sources and potential impacts, if any, to product quality can be elucidated. Based on these risk assessments, the level of action required, or not required, in terms of empirical product testing can be examined and a determination can be made regarding whether a substantial change has occurred.

The terminal sterilization of sterile orthopedic implants is a key process that, in addition to providing sterility, changes the material properties of the product and packaging. These changes might be observed during functionality testing and/or biological evaluation. We are establishing an additional sterilization process that appears promising from both a technical and business perspective. Our project aims to add X-ray sterilization to the established gamma sterilization for metallic hip and shoulder implants. To limit complexity, we started with a narrow product range. The main steps of our project journey are described here. Given that X-ray sterilization remains relatively new in terms of understanding the changes that might occur for product materials and functionality compared with changes observed following gamma radiation processing, this article highlights key steps in the change from gamma ray to X-ray sterilization.

Selection of a sterilization modality for a medical device is a critical decision that requires sterility assurance subject matter experts (SME)s to work collaboratively with various company functions. The sterility assurance SME is responsible and accountable for the sterilization modality decision for a product. The modality selection process starts with the sterility assurance SME partnering with research and development to ensure that the sterilization modality allows the device to deliver its intended function in patient care. After the sterilization modality is selected, the sterility assurance SME needs to work with other partners, including quality, supply chain/logistics, operations, and regulatory, to ensure that the selected sterilization modality is appropriately integrated into the end-to-end process. Collaborative partnerships between sterility assurance experts and key partners regarding sterilization modality selection reduce the potential for negative impacts within the end-to-end sterility assurance process, including impacts on product functionality, increased regulatory approval timelines, and inefficiencies and risks throughout the supply chain. This article describes aspects of a comprehensive approach to sterilization modality selection, including critical information necessary to address each of the key considerations.

Based on excellent material compatibility and ability for scale, ethylene oxide (EO) sterilization constitutes approximately 50% of single-use medical device sterilization globally. Epidemiological considerations have elevated focus toward optimization of EO processes, whereby only necessary amounts of sterilant are used in routine processing. EO sterilization of medical devices is validated in accordance with AAMI/ANSI/ISO 11135:2014 via a manner in which a sterility assurance level (SAL) of 10-6 is typically achieved, with multiple layers of conservativeness delivered, using "overkill" approaches to validation. Various optimization strategies are being used throughout the medical device industry to deliver the required SAL while utilizing only necessary amounts of sterilant. This article presents relevant experiences and describes challenges and considerations encountered in delivering EO process optimization. Thus far, the results observed by the authors are encouraging in demonstrating how EO processing can be optimized in the delivery of critical single-use medical devices for patient care.