IEC 61689:2013

Overview

IEC 61689:2013 is an international standard published by the International Electrotechnical Commission (IEC) that specifies field requirements and methods for measuring ultrasonic physiotherapy systems operating within the frequency range of 0.5 MHz to 5 MHz. This standard applies specifically to ultrasonic equipment designed for physiotherapy treatment using a single-plane, non-focusing circular transducer per treatment head that produces static beams perpendicular to the treatment head’s face.

The third edition of IEC 61689 updates procedures to enhance accuracy and safety during ultrasonic field measurement and characterization. It is intended for manufacturers, testing laboratories, and regulatory bodies involved in the development, testing, and certification of physiotherapy ultrasound equipment to ensure consistent quality and safety.

Key Topics

• Measurement Methods: IEC 61689:2013 defines both reference type testing and routine testing methods for the ultrasonic output. It covers hydrophone measurements, radiating area assessment, and beam characterization.
• Field Specifications: The standard sets detailed specifications for ultrasonic fields generated by physiotherapy equipment, including effective radiating area, power output, and beam non-uniformity ratio for accurate and reproducible performance.
• Safety Guidelines: Safety considerations focus on limiting cavitation risk and ensuring output intensity remains within safe thresholds. The standard introduces a maximum effective intensity of 0.2 W/cm² during hydrophone measurements for treatment heads with ka ≤ 20.
• Technical Updates: Technical changes include updating the conversion factor for effective radiating area from 1.354 to 1.333 and adopting SI units for clarity and international consistency.
• Test Equipment Conditions: Guidance on test vessels, hydrophones, signal measurement techniques, and uncertainty determination ensure reliable testing environments and repeatable results.
• Acceptance Criteria: Clear acceptance criteria for both reference and routine tests assist manufacturers and testers in determining equipment compliance with performance and safety requirements.

Applications

• Physiotherapy Device Manufacturing: Provides manufacturers with standardized procedures for output characterization, enabling design validation and quality control during production.
• Metrological Testing: Test laboratories use IEC 61689 to perform calibrations, routine inspections, and acceptance testing of ultrasonic physiotherapy systems to assure regulatory compliance and maintain high-quality therapeutic devices.
• Regulatory Compliance: Supports national and international regulatory authorities in assessing physiotherapy ultrasound equipment safety and performance, facilitating market approval processes.
• Equipment Calibration and Maintenance: Offers standardized test protocols to healthcare providers and service engineers for periodic equipment checks, ensuring reliable operation and patient safety.

Related Standards

• IEC 60601-2-5:2009: Medical electrical equipment – Part 2-5: Particular requirements for the safety of ultrasonic physiotherapy equipment. IEC 61689 is intended to be read in conjunction with this safety-focused standard.
• IEC 62127 Series: Ultrasonics – Hydrophones – The updated terminologies and definitions in IEC 61689 align more closely with these standards, which cover hydrophone calibration and measurement methods in ultrasonic fields.
• IEC 61161: Ultrasonics – Power measurement in medical applications, referenced for specific measurements related to radiation force balance techniques.
• National and Regional Medical Device Regulations: IEC 61689 supports compliance with broader regulatory frameworks governing therapeutic ultrasound devices through standardized field output characterization.

IEC 61689:2013 plays a critical role in ensuring the accuracy, safety, and consistency of ultrasonic physiotherapy equipment by establishing internationally recognized test methods and performance criteria. Manufacturers, testing agencies, and regulatory bodies rely on this standard to support the development and verification of safe, effective physiotherapy ultrasound systems within the key ultrasonic frequency range of 0.5 to 5 MHz.