prSSH EN IEC 61846:2025

Ultrasonics - Therapeutic focused short pressure pulse sources - Characteristics of fields

Scope

IEC 61846:2025 is applicable to:

– therapy equipment using extracorporeally induced focused pressure pulse waves;

– therapy equipment producing focused mechanical energy excluding thermal energy.

This document does not apply to percutaneous and laser lithotripsy equipment.

This document does not apply to:

– histotripsy or other therapeutic ultrasound bursts of longer time duration than that of the pressure pulse;

– non-focused pressure pulse equipment.

This document specifies:

– measurable parameters which could be used in the declaration of the acoustic output of extracorporeal focused pressure pulse equipment;

– methods of measurement and characterization of the pressure field generated by focused pressure pulse equipment.

While this document has been developed for equipment intended for use in lithotripsy, it has been developed such that, as long as no other specific standards are available to be used for other medical applications of therapeutic extracorporeal focused pressure pulse equipment, this document can be used as a guideline.

IEC 61846:2025 cancels and replaces the first edition published in 1998. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous edition:

a) Change of title: "pressure pulse lithotripters" in the previous edition is changed to "therapeutic focused short pressure pulse sources" in order to take into account the development in the relevant technical and biomedical applications of such sources, which were originally used only for (kidney) lithotripsy, while recent applications include a wide range for the treatment of, for example, stone diseases, orthopaedic pain, tissue, cardiac and brain diseases.

The term "focused" was added to differentiate IEC 61846 from IEC 63045.

The term "short" was added to align the nomenclature to IEC 63045 and to differentiate IEC 61846 from standards in the HIFU and HITU fields.

b) Clause 1 and elsewhere in the document: The term "lithotripsy" is changed to "therapy" in order to account for the wide range of applications beyond stone diseases.

c) Clause 3: The "−6 dB" parameter definitions are replaced by "−n dB" to avoid misconceptions in the significance and use of these parameters and to account for newer findings in literature.

Additional "n MPa" parameters are introduced for the same reasons.

The definitions of "derived" parameters are aligned to those in recently published standards, for example IEC 62127-1.

New definitions were added which describe parameters appearing in newer relevant literature, for example "momentum", "average positive acoustic pressure", "cavitation induction index", "pulse to pulse variability", "total pressure pulse energy dose".

d) Clause 6: The terms "focus hydrophone" and "field hydrophone" were removed to account for newer technical developments. New terms distinguish between "hydrophones for pressure pulse measurements" and "hydrophones for quality assurance".

e) Annexes: Descriptions, tables and figures were edited to account for newer literature and standards as well as technical developments.