NEMA UD 2-2004 (2009) PDF

Full title and description

St NEMA UD 2-2004 (R2009) — Acoustic Output Measurement Standard for Diagnostic Ultrasound Equipment, Revision 3. This NEMA/MITA standard defines measurement practices, equipment characteristics and reporting conventions for the acoustic output quantities of diagnostic ultrasound systems and transducers.

Abstract

This standard specifies methods for measuring acoustic output of diagnostic ultrasound equipment (in‑water measurements and derated tissue-representative values), hydrophone and measurement-system requirements, definitions of output quantities (for example ISPPA, Ispta, MI and TI), and reporting/notation conventions to ensure consistent, comparable acoustic output data across manufacturers and test laboratories. It also describes derating approaches used to derive tissue‑representative values from in‑water measurements.

General information

• Status: Rescinded / Withdrawn (no longer on active sale from NEMA; historical copies available through archives/vendors).
• Publication date: Original: 2004; reaffirmed/revised notation R2009 (Revision 3).
• Publisher: National Electrical Manufacturers Association (NEMA) / Medical Imaging & Technology Alliance (MITA).
• ICS / categories: Medical imaging / Diagnostic ultrasound; acoustic output measurement; ultrasound safety and device testing (ICS references commonly used for related standards include 11.040.55 and 17.140.50 for ultrasonic diagnostic equipment).
• Edition / version: UD 2-2004 (R2009) — Revision 3.
• Number of pages: Approximately 128 pages (typical published length for the UD 2-2004 (R2009) edition).

Scope

The document applies to active diagnostic ultrasound apparatus (imaging, Doppler, echo-ranging and combined systems) and establishes standardized measurement and reporting procedures for acoustic output quantities. It requires in‑water measurement techniques and specifies procedures to derive derated values that are more representative of output within tissue; the standard provides example derating (for example 0.3 dB/cm·MHz) and notation conventions for derated output quantities. The scope is intended to support consistent acoustic-output characterization across equipment types and to support regulatory and clinical considerations.

Key topics and requirements

• Definitions of acoustic output quantities (e.g., peak rarefactional pressure, pulse-intensity integral, spatial-peak temporal-average intensity, ISPPA, Ispta, MI and TI).
• Hydrophone and measurement-system characteristics, calibration and frequency response requirements for accurate field measurements.
• Standardized in‑water measurement procedures and instrumentation set-up (including beam mapping and pulse/temporal measurements).
• Derating methods to convert in‑water measurements to tissue-representative values (example: 0.3 dB/cm·MHz model and notation such as ISPPA.3), and the requirement to report both in‑water and derated values where appropriate.
• Reporting, notation and documentation requirements so manufacturers and test laboratories produce consistent, traceable acoustic output statements.
• Guidance on use and interpretation of acoustic indices and how they should be displayed or documented for users and regulatory review.

Typical use and users

Primary users of this standard are ultrasound system and transducer manufacturers, biomedical engineers, ultrasound research laboratories, instrument calibration labs (hydrophone labs), hospital physics/biomedical departments, and regulatory reviewers who evaluate diagnostic ultrasound acoustic output and safety information. The standard is used to produce manufacturer output statements, to perform compliance or characterization testing, and to inform labeling and technical documentation.

Related standards

Commonly referenced companion and international standards include IEC 60601‑2‑37 (particular requirements for ultrasonic medical diagnostic and monitoring equipment), IEC 62127 (hydrophones — measurement and characterization of medical ultrasonic fields), NEMA UD 3-2004 (R2009) on real‑time display of thermal and mechanical acoustic output indices, and AIUM/NEMA output-display guidance documents. These documents are often used together with UD 2 for safety, equipment performance and display/labeling requirements.

Keywords

Acoustic output, diagnostic ultrasound, hydrophone, derating, ISPPA, Ispta, MI, TI, measurement procedures, NEMA UD 2, ultrasound safety, diagnostic transducer testing.

FAQ

Q: What is this standard?

A: St NEMA UD 2-2004 (R2009) is NEMA’s “Acoustic Output Measurement Standard for Diagnostic Ultrasound Equipment” (Revision 3). It defines standardized measurement and reporting methods for acoustic output quantities of diagnostic ultrasound systems and transducers.

Q: What does it cover?

A: It covers in‑water measurement methods, instrument and hydrophone characteristics, definitions of acoustic output quantities, derivation and notation of derated (tissue‑representative) values, and reporting/documentation practices to ensure consistent acoustic-output characterization.

Q: Who typically uses it?

A: Ultrasound manufacturers, calibration and test laboratories, biomedical engineers, hospital medical physics/technology staff, and regulatory reviewers use the standard for device characterization, labeling, compliance support and technical reporting.

Q: Is it current or superseded?

A: The NEMA UD 2-2004 (R2009) edition is listed by NEMA as rescinded/withdrawn and is no longer offered as an active sale item on NEMA’s site; historical copies may be obtained from archival vendors. Users should check current international and national standards (for example the latest IEC 60601‑2‑37 and related guidance) for current requirements.

Q: Is it part of a series?

A: Yes. UD 2 is part of a family of NEMA documents addressing diagnostic ultrasound output and display; a closely related NEMA document is UD 3 (real‑time display of thermal and mechanical acoustic output indices). The UD series complements international standards and measurement standards (IEC and IEC-related documents) used in diagnostic ultrasound.

Q: What are the key keywords?

A: Acoustic output, hydrophone, derating, ISPPA, Ispta, mechanical index (MI), thermal index (TI), diagnostic ultrasound, measurement procedures, NEMA UD 2.