IEC 61828:2020 -提供用于医疗超声应用的聚焦和非聚焦换能器的透射场特性的定义； -将这些定义与聚焦换能器的发射场的理论描述、设计和测量相关联； -给出了用于获得聚焦和非聚焦换能器的限定场特性的测量方法； -指定适用于聚焦和非聚焦换能器的光束轴对准方法。 IEC 61828:2021涉及在适合于用于治疗和诊断应用的医疗超声(0.5 MHz至40MHz)的频率范围内操作的聚焦超声换能器。它显示了如何从设计的角度来描述换能器的传输场的特性，以及如何由不了解特定设备的结构细节的人来测量。通过水听器在标准测试介质(例如，水)或给定介质中测量用于指定激励的透射超声场。本文件仅适用于场行为基本上类似于流体中的介质（即剪切波和弹性各向异性的影响很小），包括软组织和模拟组织的凝胶。影响其理论描述或在设计中重要的领域的任何方面也包括在内。这些定义将用于科学通信、系统设计以及使用这些设备的系统的性能和安全性的描述。 IEC 61828:2021在可能的情况下纳入了其他相关标准的定义，并提供了更具体的术语，用于定义聚焦特性并为这些特性的测量提供基础。IEC 61828:2021取消并取代了2001年发布的第一版。本版构成技术修订版。 与上一版相比，此版本包括以下重大技术变更: a)关于测量程序的第6条已被第6条:“声场测量:设备”和第7条:“测量程序”及相关定义所取代。 b)重新组织定义和测量部分，以适应聚焦、非线性、射束轴对准、射束面积、射束最大值、数值投影、平面波、高强度治疗超声、多源、空间脉冲响应和复合平面波的特定测量集。第3条已移至附件B。 c)更新了规范性参考文献，参考书目从8篇扩大到40篇。d)更新了12个图，并添加了7个新图（B.1、B.3、B.7、B.10、B.11、B.12、B.13、B.14），以方便测量并与测量术语保持一致。 e)增加了时间延迟、阵列、平面波和空间脉冲响应的新测量。 f)扩展了附件A，提供了关于脉冲波、系统响应、聚焦增益和最小波束宽度估计的一般指导。 g)增加了新的附件: ？附录B（资料性）聚焦和非聚焦定义的基本原理 ？附件E（信息性）不确定性； ？附录F（信息）换能器和水听器定位系统； ？附录G（信息）水听器的平面扫描以确定声输出功率； ？附录H（信息性）水的特性； 此外，对附件A进行了重组，增加了新的A条。增加了1、A.5和A.6。 h)增加了保持在制造商的压力和强度水听器限值内以及确定现场非线性程度的指南。

IEC 61828:2020
- provides definitions for the transmitted field characteristics of focusing and nonfocusing transducers for applications in medical ultrasound;
- relates these definitions to theoretical descriptions, design, and measurement of the transmitted fields of focusing transducers;
- gives measurement methods for obtaining defined field characteristics of focusing and nonfocusing transducers;
- specifies beam axis alignment methods appropriate for focusing and nonfocusing transducers.
IEC 61828:2021 relates to focusing ultrasonic transducers operating in the frequency range appropriate to medical ultrasound (0,5 MHz to 40 MHz) for both therapeutic and diagnostic applications. It shows how the characteristics of the transmitted field of transducers can be described from the point of view of design, as well as measured by someone with no prior knowledge of the construction details of a particular device. The transmitted ultrasound field for a specified excitation is measured by a hydrophone in either a standard test medium (for example, water) or in a given medium. This document applies only to media where the field behaviour is essentially like that in a fluid (i.e. where the influence of shear waves and elastic anisotropy is small), including soft tissues and tissue-mimicking gels. Any aspects of the field that affect their theoretical description or are important in design are also included. These definitions would have use in scientific communications, system design and description of the performance and safety of systems using these devices.
IEC 61828:2021 incorporates definitions from other related standards where possible, and supplies more specific terminology, both for defining focusing characteristics and for providing a basis for measurement of these characteristics.

IEC 61828:2021 cancels and replaces the first edition published in 2001. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Clause 6 on Measurement procedures has been replaced by Clause 6: "Acoustic field measurement: equipment" and Clause 7: "Measurement procedure" and related definitions.
b) Reorganization of definitions and measurement section to accommodate specific sets of measurements for focusing, nonlinearity, beam axis alignment, beam area, beam maximum, numerical projection, plane wave, high intensity therapeutic ultrasound, multiple sources, spatial impulse response and compound plane waves. Clause 3 has been moved to Annex B.
c) The normative references have been updated and the Bibliography has been expanded from 8 to 40 references.
d) Twelve figures have been updated and seven new figures (B.1, B.3, B.7, B.10, B.11, B.12, B.13, B.14) have been added to facilitate measurements and be consistent with measurement terminology.
e) New measurements have been added for time delays, arrays, plane waves and spatial impulse response.
f) Annex A has been expanded to provide general guidance on pulsed waves, system responses, focusing gains and minimum beamwidth estimation.
g) New annexes have been added: h) Guidelines for remaining within the manufacturer’s pressure and intensity hydrophone limits and the determination of the extent of nonlinearity in the field have been added.