NEMA UD 3-2004 (R2009)

Preface to Revision Two
Preface to Revision One
Foreword
Scope
Section 1 REFERENCED PUBLICATIONS
  1.1 General
  1.2 Referenced Publications
Section 2 DEFINITIONS AND FORMULAE
  2.1 General Definitions
Section 3 RATIONALE
  3.1 Clinical Purpose
  3.2 Regulatory Purpose
      3.2.1 Purpose of Voluntary Standards
  3.3 Rationale for Choice of Indication/Display Parameter
      3.3.1 Rationale for Thermal Indices
      3.3.2 Rationale for Mechanical Index
  3.4 Rationale Regarding Diversification of Equipment Types
Section 4 INFORMATION TO BE PROVIDED TO OPERATORS
  4.1 On-Equipment Acoustic Output Indication/Display
      4.1.1 Resolution
      4.1.2 Values of Indices to be Displayed
      4.1.3 Other Conditions on Display of Indices
  4.2 Information Required in Operator's Manual
      4.2.1 Meaning of Indices and Specification of Display
            Accuracy
      4.2.2 Discussion of Operator Control Features
      4.2.3 Prudent Use Statement
Section 5 DEFAULT SETTINGS
  5.1 Equipment Designs Allowing for Full Software Control of
      Acoustic Output
  5.2 Equipment Designs Not Allowing for Full Software Control
      of Acoustic Output
Section 6 MEASUREMENT METHODOLOGY FOR MECHANICAL AND THERMAL
          INDICES
  6.1 General
  6.2 Index Measurements in Unscanned Modes
      6.2.1 Measurement of Center Frequency f[c](j) in Unscanned
            Modes
      6.2.2 Measurement of Acoustic Power (W(j, v[a])) in Unscanned
            Modes
      6.2.3 (Reserved for Future Use)
      6.2.4 Measurement of Mechanical Index MI(j, v[a]) for
            Unscanned Modes
      6.2.5 Measurement of Bone Thermal Index TIB(j, v[a]) for
            Unscanned Modes
      6.2.6 Measurement of Soft Tissue Thermal Index (TIS(j, v[a]))
            for Unscanned Modes
      6.2.7 Measurement of Cranial Bone Thermal Index TIC(j, v[a])
            for Unscanned Modes
  6.3 Index Measurements in Scanned Modes
      6.3.1 Measurement of Center Frequency f[c](j) for Scanned
            Modes
      6.3.2 Measurement of Acoustic Power (W(j, v[a])) in Scanned
            Modes
      6.3.3 Measurement of Acoustic Power per Unit Length W/X(j, v[a])
            in Scanned Modes
      6.3.4 Measurement of Mechanical Index MI(j, v[a]) for Scanned
            Modes
      6.3.5 (Reserved for Future Use)
      6.3.6 Measurement of Bone Thermal Index TIB(j, v[a]) for
            Scanned Modes
      6.3.7 Measurement of Cranial Thermal Index TIC(j, v[a]) for
            Scanned Modes
      6.3.8 Measurement of Soft Tissue Thermal Index TIS(j, v[a])
            for Scanned Modes
  6.4 Determining Display Accuracy
Appendix A SUMMARY OF THERMAL INDEX FORMULAE
  A1.1 Introduction
  A2.1 Thermal Index Concept
  A3.1 Measurement Parameters
  A4.1 Thermal Index Categories
  A5.1 Thermal Index Models
       A5.1.1 Soft Tissue at Surface [TIS (scanned), TIB (scanned)]
       A5.1.2 Soft Tissue, Unscanned, Large Aperture [TIS (unscanned)]
       A5.1.3 Soft Tissue, Unscanned, Small Aperture [TIS (unscanned)]
       A5.1.4 Bone at Focus [TIB (unscanned)]
       A5.1.5 Bone at Surface [TIC]
  A6.1 Combination Modes
  A7.1 Display of the Thermal Index
  A8.1 Measurements
Appendix B MECHANICAL INDEX RATIONALE
  B1.1 Purpose
  B2.1 Display Requirements
  B3.1 Formula
Bibliography

Applicable to diagnostic ultrasound equipment that is intended for use on humans, and is capable of exceeding a thermal index of 1.0, or a mechanical index of 1.0.