BSI PD IEC/TS 62556:2014
$215.11
Ultrasonics. Field characterization. Specification and measurement of field parameters for high intensity therapeutic ultrasound (HITU) transducers and systems
| Published By | Publication Date | Number of Pages |
| BSI | 2014 | 98 |
This technical specification is applicable to high intensity therapeutic ultrasound (HITU) devices, specifying:
-
relevant parameters for quantifying the field;
-
measurement methods at relatively low output levels and methodology for extrapolating these to higher therapeutic level fields;
-
consideration of sidelobes and pre-focal maxima;
-
parameters relevant to HITU transducers of different construction and geometry, including non-focusing, focusing with or without lenses, collimated, diverging and convergent transducers, multi-element transducers, scanning transducers and multiple sources.
This technical specification is intended to support the ultrasonic measurement requirements given in IEC 60601-2-62.
These specifications would have use in quality assurance, safety testing, and the standardization of communications regarding the clinical performance of HITU systems. Where possible, this technical specification incorporates specifications from other related standards.
This technical specification does not apply to the following types of devices, which are covered by other standards:
-
lithotripters (see IEC 61846);
-
surgical equipment (see IEC 61847);
-
physiotherapy devices (see IEC 61689).
Throughout this technical specification SI units are used. In the specification of certain parameters, such as beam-areas and intensities, it may be convenient to use decimal multiples or sub-multiples. For example, beam-area may be specified in cm2 and intensities in W/cm2 or mW/cm2.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | CONTENTS |
| 8 | FOREWORD |
| 10 | INTRODUCTION |
| 11 | 1 Scope 2 Normative references |
| 12 | 3 Terms and definitions |
| 33 | 4 List of symbols |
| 35 | 5 Independent measurement of total acoustic output power 6 Acoustic field measurement: equipment 6.1 Hydrophone 6.1.1 General |
| 36 | 6.1.2 Sensitivity of a hydrophone 6.1.3 Directional response of a hydrophone 6.1.4 Effective hydrophone radius 6.1.5 Choice of the size of a hydrophone active element |
| 37 | 6.1.6 Hydrophone pressure limits 6.1.7 Hydrophone intensity limits |
| 38 | 6.1.8 Hydrophone cable length and amplifiers 6.2 Requirements for positioning and water baths 6.2.1 General 6.2.2 Positioning systems |
| 39 | 6.2.3 Water bath |
| 40 | 6.3 Requirements for data acquisition and analysis systems |
| 41 | 6.4 Requirements and recommendations for ultrasonic equipment being characterized 7 Measurement procedure 7.1 General 7.2 Preparation and alignment 7.2.1 Initial adjustment to driving voltage |
| 42 | 7.2.2 Preparation of source transducer |
| 43 | 7.2.3 Aligning an ultrasonic transducer and hydrophone 7.2.4 Beam-axis scan 7.2.5 Measurements to be made at z = zp |
| 45 | 7.2.6 Further evaluation for sidelobes and pre-focal maxima |
| 46 | 7.3 Considerations for scanning transducers and transducers with multiple sources 7.3.1 Automatic scanning transducers 7.4 Linear extrapolation of field values 7.4.1 General |
| 47 | 7.4.2 Calculation of Isal 7.4.3 Scaling for sidelobes and pre-focal maxima 7.5 Reporting |
| 49 | Figures FigureĀ 1 ā Schematic diagram of the different planes and lines in an ultrasonic field for a rectangular HITU transducer |
| 50 | FigureĀ 2 ā Schematic diagram of the different planes and lines in an ultrasonic field for a circularly symmetric HITU transducer |
| 51 | FigureĀ 3 ā Schematic diagram of the different planes and lines in an ultrasonic field for a circularly symmetric HITU transducer with a circular hole in its center |
| 52 | FigureĀ 4 ā Schematic diagram of the different planes and lines in an ultrasonic field for a circularly symmetric HITU transducer with a rectangular hole in its center for a diagnostic transducer (HITU transducer azimuth axis aligned with azimuth scan axis of diagnostic transducer) |
| 53 | FigureĀ 5 ā Parameters for describing a focusing transducer of an unknown geometry (IECĀ 61828) |
| 54 | FigureĀ 6 ā Overall measurement scheme |
| 55 | Annex A (informative) Rationale A.1 General A.2 Detailed discussion of difficulties in HITU field measurements A.2.1 Very high pressures |
| 56 | A.2.2 Very high intensities A.2.3 Strong focusing A.2.4 Nonlinear harmonics |
| 57 | A.2.5 Acoustic saturation and nonlinear loss A.2.6 Damage to hydrophones may only be apparent at high pressures A.3 Approach of this technical specification |
| 59 | Annex B (informative) Assessment of uncertainty in the acoustic quantities obtained by hydrophone measurements B.1 General B.2 Overall (expanded) uncertainty B.3 Common sources of uncertainty |
| 61 | Annex C (informative) Transducer and hydrophone positioning systems FigureĀ C.1 ā Schematic diagram of the ultrasonic transducer and hydrophone degrees of freedom. X, Y and Z denote the axis directions relative to the mounted hydrophone and ultrasonic transducer. |
| 62 | Annex D (informative) Rationale for Isal D.1 General rationale D.2 Determination of Pc,6 using hydrophone measurements and extrapolation from linear measurements. D.3 Alternative determination of Pc,6 using an aperture in combination with a measurement of total acoustic output power |
| 63 | D.4 Special case of uniformly vibrating spherically shaped transducers |
| 64 | Annex E (normative) Propagation and back-propagation methods for field reconstruction: basic formulae and requirements E.1 Motivation and background E.2 Theory E.2.1 General |
| 65 | FigureĀ E.1 ā Geometry of problem for forward and backward projection techniques. |
| 66 | E.2.2 Fourier projection approach |
| 68 | FigureĀ E.2 ā Transducer focused at ā15mm, y = 48,16 mm, z = 56,85 mm |
| 69 | E.2.3 Rayleigh integral approach |
| 70 | E.3 Implementation E.3.1 General E.3.2 Recommendations for hydrophone |
| 71 | E.3.3 Recommendation for planar scan parameters |
| 72 | FigureĀ E.3 ā Selection of acquisition window |
| 73 | E.4 Assessment of uncertainties FigureĀ E.4 ā Scanned field compared to its reconstruction from a finite window |
| 75 | Annex F (informative) Propagation and back-propagation methods for field reconstruction: examples and uses F.1 Examples F.1.1 Fourier projection example FigureĀ F.1 ā Transducer inside 2-axis scanner setup |
| 76 | FigureĀ F.2 ā Pressure amplitude as scanned |
| 77 | FigureĀ F.3 ā Reconstructed pressure amplitude distribution in 3 orthogonal planes that contain the focal point |
| 78 | FigureĀ F.4 ā 3D representation of the focal beam for nominal focus at x = ā0,85Ā mm, yĀ =Ā ā0,25Ā mm, z = 58,95Ā mm |
| 79 | F.1.2 Rayleigh integral projection example FigureĀ F.5 ā Reconstruction of pressure amplitudes on the transducer surface (transducer aperture plane) |
| 80 | FigureĀ F.6 ā Experimental arrangement |
| 81 | FigureĀ F.7 ā Amplitude and phase distribution of acoustic pressure measured at the scanning region FigureĀ F.8 ā Amplitude and phase distribution of acoustic pressure reconstructed at the transducer aperture plane |
| 82 | FigureĀ F.9 ā Comparison of the axial distribution of pressure amplitudes as projected from the aperture plane (red) and as measured (blue) |
| 83 | F.2 Other propagation method applications FigureĀ F.10 āComparison of the schlieren image (A) and the corresponding YZ distribution of acoustic pressure amplitudes projected from the transducer aperture plane (B) |
| 84 | Annex G (normative) Planar scanning of a hydrophone to determine acoustic output power G.1 Introduction G.2 General principle |
| 85 | G.3 Hydrophone scanning methodology G.3.1 General methodology |
| 86 | G.3.2 Particular considerations for implementation for HITU fields G.4 Corrections and sources of measurement uncertainty G.4.1 Uncertainty in the hydrophone calibration G.4.2 Planar scanning |
| 87 | G.4.3 Attenuation factor of water: unfocusing transducers G.4.4 Attenuation factor of water: focusing transducers G.4.5 Received hydrophone signal |
| 88 | G.4.6 Integration G.4.7 Finite size of the hydrophone G.4.8 partial extent of integration G.4.9 Non-linear propagation |
| 89 | G.4.10 Directional response G.4.11 Noise G.4.12 Intensity approximated by derived intensity |
| 90 | Annex H (informative) Properties of water H.1 General Tables Table H.1 ā Speed of sound c [35, 36] and characteristic acoustic impedance, Ļ c, as a function of temperature, for propagation in water |
| 91 | H.2 Attenuation coefficient for propagation in water |
| 92 | Annex I (informative) Propagation medium and degassing |
| 93 | Bibliography |
Related products
-
BSI PD IEC/TS 62556:2014
Ultrasonics. Field characterization. Specification and measurement of field parameters for high intensity therapeutic ultrasound (HITU)ā¦
