• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Scientific Publications by FDA Staff

  • Print
  • Share
  • E-mail
-

Search Publications



Fields



Centers











Starting Date


Ending Date


Order by

Entry Details

IEEE Trans Ultrason Ferroelectr 2014 Jan;61(1):62-75

Improved measurement of acoustic output using complex deconvolution of hydrophone sensitivity.

Wear K, Gammell P, Maruvada S, Liu Y, Harris G

Abstract

The traditional method for calculating acoustic pressure amplitude is to divide a hydrophone output voltage measurement by the hydrophone sensitivity at the acoustic working frequency, but this approach neglects frequency dependence of hydrophone sensitivity. Another method is to perform a complex deconvolution between the hydrophone output waveform and the hydrophone impulse response (the inverse Fourier transform of the sensitivity). In this paper, the effects of deconvolution on measurements of peak compressional pressure (p+), peak rarefactional pressure (p inverted question mark), and pulse intensity integral (PII) are studied. Time-delay spectrometry (TDS) was used to measure complex sensitivities from 1 to 40 MHz for 8 hydrophones used in medical ultrasound exposimetry. These included polyvinylidene fluoride (PVDF) spot-poled membrane, needle, capsule, and fiber-optic designs. Subsequently, the 8 hydrophones were used to measure a 4-cycle, 3 MHz pressure waveform mimicking a pulsed Doppler waveform. Acoustic parameters were measured for the 8 hydrophones using the traditional approach and deconvolution. Average measurements (across all 8 hydrophones) of acoustic parameters from deconvolved waveforms were 4.8 MPa (p+), 2.4 MPa (p inverted question mark), and 0.21 mJ/cm2 (PII). Compared with the traditional method, deconvolution reduced the coefficient of variation (ratio of standard deviation to mean across all 8 hydrophones) from 29% to 8% (p+), 39% to 13% (p inverted question mark), and 58% to 10% (PII).


Category: Journal Article
PubMed ID: #24402896 DOI: 10.1109/TUFFC.2014.6689776
Includes FDA Authors from Scientific Area(s): Medical Devices
Entry Created: 2014-02-07 Entry Last Modified: 2014-11-18
Feedback
-
-