IEC 61828:2001

Overview

IEC 61828:2001 - Ultrasonics: Focusing transducers - Definitions and measurement methods for the transmitted fields defines how to describe, measure and align the transmitted ultrasonic fields of focusing transducers used in medical ultrasound. The standard links theoretical descriptions and design parameters with practical measurement techniques, enabling consistent characterization of focusing behavior across diagnostic and therapeutic devices operating in the 0.5 MHz to 40 MHz band.

Key topics and requirements

• Definitions of focusing characteristics: Quantitative terminology for what constitutes a focusing transducer versus a non‑focusing device, and the focal parameters used to describe a focused field (beamwidth, focal location, pressure concentration, etc.).
• Relation to design and theory: How field descriptors map to transducer geometry and focusing methods (curved faces, lenses, phased arrays, etc.) without requiring knowledge of internal construction.
• Measurement methods: Procedures for determining transmitted field characteristics using hydrophone measurements in a standard test medium (commonly water) or other media where fluid‑like acoustic behavior applies (soft tissue, tissue‑mimicking gels).
• Beam axis alignment: Recommended techniques to find and align the beam axis for focusing transducers, including guidance for well‑behaved and asymmetric beams.
• Scope limits: Applies only to media where shear-wave effects and elastic anisotropy are negligible; covers both therapeutic and diagnostic applications.
• Normative linkage: Cross-references standards for hydrophone measurement and acoustic output declaration (e.g., IEC 61102, IEC 61157).

Applications and who uses it

IEC 61828 is practical for:

• Medical ultrasound manufacturers - to specify and verify focusing performance during design and production.
• Test laboratories and QA teams - for standardized hydrophone measurement setups and repeatable focal parameter extraction.
• Researchers and developers - to compare focused-field results across devices and publications using consistent definitions.
• Regulatory and safety engineers - to interpret acoustic output and focal properties relevant to performance and safety assessments.
• Clinical engineers - when assessing or documenting device performance for imaging or therapeutic procedures.

Practical value and keywords

IEC 61828 standardizes how to measure and report transmitted fields, beamwidth, focal location, and pressure focus of focusing transducers in medical ultrasound. By defining measurement methods (hydrophone in water or tissue-mimicking media) and beam axis alignment techniques, it helps ensure reproducible performance data for device design, safety declarations and scientific communication.

Related standards

• IEC 61102 - Measurement and characterization of ultrasonic fields using hydrophones (0.5 MHz to 15 MHz)
• IEC 61157 - Requirements for declaration of acoustic output of medical diagnostic ultrasound equipment
• IEC 61689 - Ultrasonics - Physiotherapy systems (relevant frequency range)