IEC TS 62556:2014 PDF

Overview

IEC TS 62556:2014 - "Ultrasonics - Field characterization - Specification and measurement of field parameters for high intensity therapeutic ultrasound (HITU) transducers and systems" - is a technical specification that defines how to quantify and measure acoustic fields produced by HITU (high intensity therapeutic ultrasound) devices. It prescribes relevant field parameters, measurement methods at low output levels and procedures to extrapolate to therapeutic levels, and offers guidance for diverse transducer geometries (focusing, non‑focusing, multi‑element, scanning, collimated/diverging/convergent). The specification supports the ultrasonic measurement requirements in IEC 60601‑2‑62 and is intended for quality assurance, safety testing, and standardized communication of clinical performance.

Key topics and requirements

• Field parameter definitions: Parameters required to describe HITU acoustic fields, including sidelobes and pre‑focal maxima.
• Measurement approach: Procedures for hydrophone‑based measurements at relatively low outputs and methodologies for linear extrapolation to higher therapeutic levels.
• Hydrophone guidance: Selection, sensitivity, directional response, effective element size, pressure/intensity limits and calibration considerations.
• Positioning and water bath: Requirements for positioning systems, scanning rigs and water bath conditions for reproducible field mapping.
• Data acquisition & analysis: Requirements for acquisition systems, signal processing and uncertainty assessment.
• Scan and reconstruction methods: Planar hydrophone scanning to determine total acoustic output power and propagation/back‑propagation methods (Fourier projection, Rayleigh integral) for field reconstruction.
• Uncertainty and rationale: Annexes covering uncertainty assessment, measurement limitations (nonlinear propagation, hydrophone damage) and rationale for chosen metrics.
• Reporting: Recommended reporting items and procedures to ensure consistent documentation of HITU field measurements.

Practical applications and users

Who uses IEC TS 62556:

• Medical device manufacturers developing HITU transducers and treatment systems.
• Metrology laboratories performing acoustic output power and field characterization.
• Regulatory and clinical engineers conducting safety testing and quality assurance.
• Research groups studying focused ultrasound therapy performance and dosimetry.

Practical uses:

• Standardizing field measurements for device certification and regulatory submissions.
• Designing test setups (hydrophone selection, scanner configuration, water properties).
• Comparing clinical device performance and communicating acoustic output consistently across vendors.

Related standards

• Supports: IEC 60601‑2‑62 (medical electrical equipment - HITU systems)
• Not applicable to devices covered by: IEC 61846 (lithotripters), IEC 61847 (surgical ultrasound), IEC 61689 (physiotherapy)

Keywords: IEC TS 62556, HITU, high intensity therapeutic ultrasound, field characterization, hydrophone measurement, acoustic output, planar scanning, propagation methods, IEC 60601‑2‑62.