Page 13 - HydrophoneHandbook_eReader_Ed2_20151208
P. 13

Choosing a Hydrophone

Understanding the application is a good starting point to help
select the appropriate hydrophone. The ranges of key acoustic
parameters will vary for different applications. The table below
was adapted from information published in “Output
Measurements for Medical Ultrasound” (1991).

  Pressure   Broadband   Narrow-     Physio-    HIFU /   Lithotripsy
   (MPa)      Imaging 1    band     therapy 3   HITU 4
    Ispta                            0.1-0.3   Up to 50    10-100
                 1-8     Imaging 2              Up to       N/A 5
 (mW/cm2)        720        1-5                 80,000      N/A 5
Total Power  0.002-0.25                         2-500      0.2-0.9
                 1-60    720 Up to 3000        0.25-10
     (W)          40                                          40
 Frequency               0.02-0.25  Up to 15      40

   (MHz)                 2-30 0.75-3.0
Bandwidth
                         0.05 0.05
  (MHz) 6

Notes:
1 Broadband imaging: typically gray scale (such as B-mode, Tissue-
Harmonic), M-mode, or A-mode
2 Narrowband imaging: typically Doppler (pulsed or CW) or color
Doppler
3 Physiotherapy: refers to traditional diathermy devices as covered
under IEC 60601-2-5
4 HIFU/HITU: high-field-strength ultrasound therapy not covered
under lithotripsy or physiotherapy
5 Power and intensity are extremely low for typical physiotherapy
applications because of low duty factor and repetition rate
6 Bandwidth refers to typical bandwidth requirements for the
hydrophone, due to presence of nonlinear harmonics due to
nonlinear properties of water—i.e., this is typically greater than
imaging bandwidth or the bandwidth of driving or receiving
electronics

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