1.1 本标准的目的是概述适当的实验方法，用于对 体外 由可吸收金属或合金制成的装置或试样的降解性能。 1.2 所述实验方法旨在通过标准化条件和利用生理相关电解质液体来控制腐蚀试验环境。还纳入了标准化降解控制材料的评估，以促进跨实验室结果的比较和标准化。 1.3 获得的测试结果可用于在评估更精细的制造设备之前筛选材料和/或结构。 所述测试还可用于在更广泛的测试之前定义设备的性能阈值 体外 性能评估（例如疲劳测试）或 体内 评估。 1.4 本标准适用于所有可吸收金属，包括镁、铁和锌基金属和合金。 1.5 所述测试不代表 体内 并可能提供比可吸收金属实际降解速度更快或更慢的降解速度 体内 腐蚀速率。本文所述的试验方法仅用于材料比较目的，不得作为预测或替代材料评估 体内 设备的劣化特性。 1.6 本标准仅提供以下方面的指导: 体外 可吸收金属的降解，未涉及任何方面 体内 或生物相容性评估。 1.7 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本标准提供了潜在 体外 评估可吸收金属降解的试验方法。所提供的方法取决于本标准的用户根据预期应用的具体要求选择最合适的方法。然而，至少有两种不同的腐蚀评估方法被认为是对材料或装置进行基本分析所必需的，并且可能需要额外的方法来进行充分的表征。然而，在某些情况下，可能只有一种方法与 体内 降解结果。 5.2 人们认识到，并非所有测试方法都对每种情况都有意义。 此外，一些方法在相对近似于 体内 实际使用的条件。因此，本指南对所述方法的相关性进行了一些讨论和排序。 5.3 应注意，可吸收金属的降解不是线性的。因此，应采取预防措施，对金属或金属装置的降解曲线进行适当的评估，以反映不同的降解阶段和速率。相关因素可以包括植入设备的组织覆盖量或百分比（%）和周围组织的代谢率，这不一定伴随着高灌注率。 5.4 人们认识到 体内 即使与其他环境相比，环境也会带来直接影响腐蚀速率的特殊考虑因素 体内 位置。因此，需要对特定靶向植入位置（例如硬组织；软组织；高、低或零灌注区域/组织；高、低或零负荷环境）的生物化学和生理学有基本了解，以优化 体外 和 体内 评估。 5.5 在可吸收金属的评估中，速率均匀性被视为主要关注点和设计目标。本文中描述的识别主要值 体外 静态测试（即。 非动态）条件是监测和筛选材料和/或设备的腐蚀一致性。这种评估可以在任何后续操作之前提供对设备均匀性的实际理解 体内 测试-设备一致性被认为是优化所获得观察结果质量的关键。 5.6 一旦确定了合适的设备腐蚀一致性水平（直接或历史），然后可以进行静态和/或动态疲劳测试（如需要），以进一步提高对设备总体设计及其预期应用/用途范围内腐蚀过程的理解。 5.7 根据预期应用，植入物负荷的适当水平可能从最小到严重不等。因此，本标准并不直接涉及可吸收金属装置的适当负载水平，可在特定于预期植入应用和产品设计要求的文件中找到相关指南。 5.8 本标准不直接涉及可吸收金属装置的动态疲劳试验。

1.1 The purpose of this standard is to outline appropriate experimental approaches for conducting an initial evaluation of the in vitro degradation properties of a device or test sample fabricated from an absorbable metal or alloy. 1.2 The described experimental approaches are intended to control the corrosion test environment through standardization of conditions and utilization of physiologically relevant electrolyte fluids. Evaluation of a standardized degradation control material is also incorporated to facilitate comparison and normalization of results across laboratories. 1.3 The obtained test results may be used to screen materials and/or constructs prior to evaluation of a more refined fabricated device. The described tests may also be utilized to define a device’s performance threshold prior to more extensive in vitro performance evaluations (e.g. fatigue testing) or in vivo evaluations. 1.4 This standard is considered to be applicable to all absorbable metals, including magnesium, iron, and zinc-based metals and alloys. 1.5 The described tests are not considered to be representative of in vivo conditions and could potentially provide a more rapid or slower degradation rate than an absorbable metal’s actual in vivo corrosion rate. The herein described test methods are to be used for material comparison purposes only and are not to act as either a predictor or substitute for evaluation of the in vivo degradation properties of a device. 1.6 This standard only provides guidance regarding the in vitro degradation of absorbable metals and does not address any aspect regarding either in vivo or biocompatibility evaluations. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This standard provides an itemization of potential in vitro test methods to evaluate the degradation of absorbable metals. The provided approach defers to the user of this standard to pick most appropriate method(s) based on the specific requirements of the intended application. However, a minimum of at least two different corrosion evaluation methods is considered necessary for basic profiling of the material or device, with additional methods potentially needed for an adequate characterization. However, in some instances there may be only one method that correlates to in vivo degradation results. 5.2 It is recognized that not all test methods will be meaningful for every situation. In addition, some methods carry different potential than others regarding their relative approximation to the in vivo conditions within which actual use is to occur. As a result, some discussion and ranking of the relevance of the described methods is provided by this guidance. 5.3 It should be noted that degradation of absorbable metals is not linear. Thus, precautions should be taken that evaluations of the degradation profile of a metal or metal device are appropriately adapted to reflect the varying stages and rates of degradation. Relevant factors can include the amount or percentage (%) of tissue coverage of the implanted device and the metabolic rate of surrounding tissue, which is not necessarily accompanied by a high perfusion rate. 5.4 It is recognized that in vivo environments will impart specialized considerations that can directly affect the corrosion rate, even when compared with other in vivo locations. Thus, a basic understanding of the biochemistry and physiology of the specific targeted implant location (e.g. hard tissue; soft tissue; high, low or zero perfusion areas/tissue; high, low or zero loading environments) is needed to optimize in vitro and in vivo evaluations. 5.5 Within the evaluation of absorbable metals, rate uniformity is considered to be the principle concern and design goal. The recognized primary value for the herein described in vitro testing under static (i.e. not dynamic) conditions is to monitor and screen materials and/or devices for their corrosion consistency. Such an evaluation may provide a practical understanding of the uniformity of the device prior to any subsequent in vivo testing - where device consistency is considered to be critical for optimizing the quality of the obtained observations. 5.6 Once a suitable level of device corrosion consistency has been established (either directly or historically), static and/or dynamic fatigue testing can then be undertaken, if needed, to further enhance the understanding of the corrosion process within the context of the device’s overall design and its intended application/use. 5.7 Depending on the intended application, appropriate levels of implant loading may range from minimal to severe. Thus, this standard does NOT directly address the appropriate level of loading of absorbable metallic devices, guidance for which may be found in documents specific to the intended implant application and the design requirements for the product. 5.8 This standard does NOT directly address dynamic fatigue testing of absorbable metallic devices.