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BS EN 61689:2007 Ultrasonics. Physiotherapy systems. Field specifications and methods of measurement in the frequency range 0,5 MHz to 5 MHz, 2007
- CONTENTS
- FOREWORD
- INTRODUCTION
- 1 Scope
- 2 Normative references
- 3 Terms and definitions
- 4 List of symbols
- 5 Ultrasonic field specifications
- 6 Conditions of measurement and test equipment used [Go to Page]
- 6.1 General
- 6.2 Test vessel
- 6.3 Hydrophone
- 6.4 RMS or peak signal measurement
- 7 Type testing reference procedures and measurements [Go to Page]
- 7.1 General
- 7.2 Rated output power
- 7.3 Hydrophone measurements
- 7.4 Effective radiating area
- 7.5 Reference type testing parameters
- 7.6 Acceptance criteria for reference type testing
- 8 Routine measurement procedure [Go to Page]
- 8.1 General
- 8.2 Rated output power
- 8.3 Effective radiating area
- 8.4 Beam non-uniformity ratio
- 8.5 Effective intensity
- 8.6 Acceptance criteria for routine testing
- 9 Sampling and uncertainty determination [Go to Page]
- 9.1 Reference type testing measurements
- 9.2 Routine measurements
- 9.3 Uncertainty determination
- Annex A (informative) Guidance for performance and safety
- Annex B (normative) Raster scan measurement and analysis procedures
- Annex C (normative) Diametrical or line scan measurement and analysis procedures
- Annex D (informative) Rationale concerning the beam cross-sectional area definition
- Annex E (informative) Factor used to convert the beam cross-sectional area (ABCS) at the face of the treatment head to the effective radiating area (AER)
- Annex F (informative) Determining acoustic power through radiation force measurements
- Annex G (informative) The validity of low-power measurements of the beam cross-sectional area (ABCS)
- Annex H (informative) Influence of hydrophone effective diameter
- Annex I (informative) Effective radiating area measurement using a radiation force balance and absorbing apertures
- Annex J (informative) Guidance on uncertainty determination
- Bibliography
- Figures [Go to Page]
- Figure A.1 – The normalized, time-averaged values of the acoustic intensity (unbroken line) and of one of its plane-wave approximations (broken line), existing on the axis of a circular piston source of ka = 30, versus the normalized distance s, where s = λz//a2
- Figure A.2 – Histogram of RBN values for 37 treatment heads of various diameter and frequency
- Figure D.1 – Iso-pressure lines of a typical physiotherapy treatment head of small geometrical area (ka = 17)
- Figure D.2 – Plot of beam cross-sectional area against different limit values for a small variation in distance along the beam alignment axis, z
- Figure D.3 – Normalized values of beam cross-sectional area for IEC and FDA limit values for five transducers of different ka values, z = 0,5 cm
- Figure D.4 – Variation of the beam cross-sectional area (ABCS) with distance from the face of the treatment head
- Figure D.5 – Variation of the normalized beam cross-sectional area (ABCS) with transducer ka
- Figure E.1 – Conversion factor Fac as a function of the ka product for ka product between 40 and 160
- Figure I.1 – Schematic representation of aperture measurement set-up
- Figure I.2 – Measured power as a function of aperture diameter for commercially-available 1 MHz physiotherapy treatment heads
- Figure I.3 – Cumulative sum of annular power contributions, previously sorted in descending order of intensity contribution, plotted against the cumulative sum of their respective annular areas
- Tables [Go to Page]
- Table C.1 – Constitution of the transformed array [B] used for the analysis of half-line scans
- Table F.1 – Necessary target size, expressed as the minimum target radius b, as a function of the ultrasonic frequency, f, the effective radius of the treatment head, a1, and the target distance, z, calculated according to 5.3 of IEC 61161 (see [5])
- Table G.1 – Variation of the beam cross-sectional area (ABCS(z)) with the indicated output power from two transducers
- Table H.1 – Comparison of measurements of the beam cross-sectional area (ABCS(z)) made using hydrophones of geometrical active element radii 0,3 mm, 0,5 mm and 2,0 mm
- Table I.1 – Aperture measurement check sheet
- Table I.2 – Annular power contributions
- Table I.3 – Annular intensity contributions
- Table I.4 – Annular intensity contributions, sorted in descending order
- Table I.5 – Annular power contributions, sorted in descending order of intensity contribution
- Table I.6 – Cumulative sum of annular power contributions, previously sorted in descending order of intensity contribution, and the cumulative sum of their respective annular areas [Go to Page]
