1.1 本规范涵盖了一系列建议，通常适用于所有医疗器械，用于表征颗粒的形态、形状、尺寸和尺寸分布。使用的方法包括筛子、光学、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和电光。 1.2 虽然表征从医疗器械脱落的颗粒的数量或数量很重要，但这不在当前文件的范围内。AAMI TIR 42和USP<788>提供了测定各种尺寸范围内颗粒量的指南。 1.3 这些方法适用于通过许多不同方法产生的颗粒。这些方法可以包括模拟使用方法，例如 体外 磨损试验机（试验方法 F732 ）、全关节模拟系统（指南 F1714 和 F1715 ）、磨损试验和血管耐久性试验（指南 F2942 ).可以使用用于生产颗粒的其他方法，例如粉碎箱或粉碎机，以及市售颗粒和从动物或临床研究中的组织收获的颗粒。 1.4 除化学成分外，本标准不涉及可能受化学性质（例如溶解度、混溶性）影响的样品制备程序和/或测试系统。虽然本标准没有提供关于颗粒化学性质评估的详细建议，但应考虑这些建议。 1.5 颗粒可以是金属的、聚合物的或陶瓷的，并且急性或慢性地(例如，由于磨损)从医疗装置材料中释放。 1.6 使用的消解程序和回收颗粒的灭菌问题不是本实践的主题。 1.7 描述颗粒形态的分类方案包括在 附录X3 . 1.8 当已知或预期存在纳米颗粒(即，具有至少一个小于100nm的尺寸)时，可能需要其他表征方法。有关纳米颗粒表征的信息，请参考针对纳米颗粒的标准(例如，ISO 21363、ISO/TR 10993-22、ISO/TR 16196)。 1.9 本标准不涉及医疗器械释放的离子。 1.10 以SI单位表示的值，包括正式接受用于SI的单位，应被视为标准值。本标准中不包括其他测量系统。1.11 作为微粒表征分析期间处理供试品的预防性安全措施，应通过不会对这些微粒产生不利影响的适当方法对植入物组织中取出的微粒进行灭菌或最低限度消毒。 1.12 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.13 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》中确立的国际公认的标准化原则制定的。======意义和用途====== 5.1 对由植入物磨损、磨损或侵蚀产生的小颗粒形式的材料的生物响应通常显著不同于对块状形式的相同材料(即，植入物组件)的生物响应。此外，这些颗粒的形态（例如，尺寸和形状、表面特征）、体积分布和种类是设备相关生物响应的主要决定因素；因此，本实践提供了描述粒子的标准化命名法。这种统一的命名法在解释对颗粒的响应的生物学测试中是有价值的，因为它将有助于根据不同的颗粒特征(例如尺寸、形状和体积)分离生物响应。5.2 由于植入物磨损而释放的颗粒 体内 可能导致不良生物学反应，影响器械的长期存活。这种颗粒的表征将提供关于装置设计的安全性和有效性或处理部件的方法以及磨损机制的有价值的信息。 5.3 在磨损和磨损的实验室测试中产生的颗粒的形态通常受到测试条件的影响，例如负载施加的大小和速率、设备配置和测试环境。产生的颗粒的形态、尺寸和数量的比较 体外 与生产的 体内 将提供有关该方法模拟的程度的有价值的信息 体内 正在建模的条件。 5.4 从颗粒释放研究（例如，细胞培养实验、第三体磨损模拟）中收获的用于测试的颗粒应代表临床使用所审查器械/材料（例如，由于磨损、磨损或侵蚀）产生的所有可能颗粒。因此，应努力确保用于测试的颗粒是由 体内 / 体外 尽可能模拟临床使用条件的研究。当产生的颗粒的特性存在不确定性时 体外 或台架测试，来自临床研究(例如，检索)的颗粒可用于增强测试的临床代表性及其表征潜在生物反应的预测能力。

1.1 This practice covers a series of recommendations, generally applicable to all medical devices, for characterization of the morphology, shape, size, and size distribution of particles. The methods utilized include sieves, optical, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrooptical. 1.2 While characterizing the quantity or number of particles shed from medical devices is important, this is not covered within the scope of the current document. AAMI TIR 42 and USP <788> provide guidelines for determination of particle quantities in various size ranges. 1.3 These methods are appropriate for particles produced by a number of different methods. These methods can include simulated use approaches such as in vitro wear test machines (Test Method F732 ), total joint simulation systems (Guides F1714 and F1715 ), abrasion testing, and vascular durability testing (Guide F2942 ). Other methods for producing particles such as shatter boxes or pulverizers, as well as commercially available particles, and particles harvested from tissues in animal or clinical studies can be used. 1.4 Except for chemical composition, this standard does not address sample preparation procedures and/or test systems that can be affected by chemical properties (for example, solubility, miscibility). While this standard does not provide detailed recommendations regarding assessment of chemical properties of particles, these should be considered. 1.5 The particles may be metallic, polymeric, or ceramic and are released from medical device materials either acutely or chronically (for example, due to wear). 1.6 The digestion procedures to be used and issues of sterilization of retrieved particles are not the subject of this practice. 1.7 A classification scheme for description of particle morphology is included in Appendix X3 . 1.8 When nanoparticles (that is, having at least one dimension less than 100 nm) are known to be present or are expected, other characterization methods may be needed. For information regarding nanoparticle characterization, refer to standards that address nanoparticles (for example, ISO 21363, ISO/TR 10993-22, ISO/TR 16196). 1.9 This standard does not address ions released from medical devices. 1.10 The values stated in SI units, including units officially accepted for use with SI, are to be regarded as standard. No other systems of measurement are included in this standard. 1.11 As a precautionary safety measure for handling test samples during particle characterization analyses, removed particles from implant tissues should be sterilized or minimally disinfected by an appropriate means that does not adversely affect these particles. 1.12 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. 1.13 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 The biological response to materials in the form of small particles, as produced from implant wear, abrasion, or erosion, often is significantly different from that to the same materials in bulk form (that is, an implant component). Additionally, the morphology (for example, size and shape, surface characteristics), volume distribution, and species of these particles are major determinants of device-related biological responses; therefore, this practice provides standardized nomenclature for describing particles. Such a unified nomenclature will be of value in interpretation of biological tests of responses to particles, in that it will facilitate separation of biological responses per different particle characteristics such as size, shape, and volume. 5.2 Particles released due to wear from implants in vivo may result in an adverse biological response which will affect the long-term survival of the device. Characterization of such particles will provide valuable information regarding the safety and effectiveness of device designs or methods of processing components and the mechanisms of wear. 5.3 The morphology of particles produced in laboratory tests of wear and abrasion often is affected by the test conditions, such as the magnitude and rate of load application, device configuration, and test environment. Comparison of the morphology, size, and quantity of particles produced in vitro with those produced in vivo will provide valuable information regarding the degree to which the method simulates the in vivo condition being modeled. 5.4 Particles harvested from particle-release studies (for example, cell culture experiments, third body wear simulation) that are to be used for testing should be representative of the entire spectrum of possible particles produced from clinical use of the device/material under review (for example, due to wear, abrasion, or erosion). Therefore, efforts should be made to ensure that the particles for testing were produced from in vivo / in vitro studies that mimicked the clinical use conditions as much as possible. When there is uncertainty regarding the characteristics of particles produced from in vitro or bench testing, particles from clinical studies (for example, retrievals) can be used to enhance the clinical representativeness of testing and its predictive power for characterizing potential biological responses.