IEC 61689:2022

Overview

IEC 61689:2022 - Ultrasonics - Physiotherapy systems - Field specifications and methods of measurement in the frequency range 0.5 MHz to 5 MHz - defines how to measure, characterize and specify the ultrasonic output of physiotherapy equipment that uses a single-plane non-focusing circular transducer per treatment head producing static beams perpendicular to the face.
The standard covers type testing (reference procedures) and routine testing (production/acceptance), specifies measurement conditions and test equipment, and provides guidance on safety of the ultrasonic field. It does not cover therapeutic value or clinical methods of use. (Note: devices operating 20 kHz–500 kHz are covered by IEC 63009.)

Key topics and technical requirements

• Scope and terminology: Updated terms and definitions aligned with TC 87 documents; applies to continuous and quasi-continuous (e.g., tone burst) ultrasound in 0.5–5 MHz.
• Measurement conditions: Test vessel, hydrophone specifications and positioning, and requirements for RMS/peak signal measurement.
• Type testing (reference procedures): Methods to measure rated output power, effective radiating area (ERA), beam cross-sectional area, and beam non‑uniformity ratio (BNR) using hydrophone scans (raster, diametrical/line scans) and radiation-force/aperture methods.
• Routine testing: Simplified, repeatable measurement procedures and acceptance criteria for production and maintenance checks.
• Safety and performance guidance: Normative Annex A now includes how conformance with IEC 60601-2-5 requirements is checked; guidance on effective intensity and BNR rationale.
• Uncertainty & sampling: Methods for uncertainty determination and sampling plans for reference and routine measurements.
• Notable technical changes (edition 4.0):
  • Water oxygen content requirement added;
  • Former recommendations tightened into requirements;
  • Annex A elevated to normative (conformance checks for IEC 60601-2-5);
  • Annex D shortened and obsolete regulatory references removed.

Practical applications and users

Who uses IEC 61689:2022:

• Medical device manufacturers - design verification, product specification, labeling of ultrasonic physiotherapy heads.
• Test and calibration laboratories - performing reference hydrophone scans, radiation force balance tests, ERA determination, and uncertainty analysis.
• Regulatory bodies and conformity assessors - assessing compliance with field-output safety and performance requirements.
• Hospital biomedical engineers and procurement teams - acceptance testing, routine maintenance checks, and purchase specifications.
• Quality assurance teams - establishing production acceptance criteria and release testing.

Related standards

• IEC 63009 - ultrasonics for physiotherapy at 20 kHz–500 kHz.
• IEC 60601-2-5 - medical electrical equipment - particular requirements for ultrasonic physiotherapy equipment (conformance checks referenced in Annex A).

Keywords: IEC 61689:2022, ultrasonics, physiotherapy systems, measurement methods, effective radiating area, hydrophone, beam non‑uniformity ratio, radiation force balance, type testing, routine testing.