Handheld photoacoustic tomography probe built using optical-fiber parallel acoustic delay lines

J Biomed Opt. 2014 Aug;19(8):086007. doi: 10.1117/1.JBO.19.8.086007.

Abstract

The development of the first miniaturized parallel acoustic delay line (PADL) probe for handheld photoacoustic tomography (PAT) is reported. Using fused-silica optical fibers with low acoustic attenuation, we constructed two arrays of eight PADLs. Precision laser micromachining was conducted to produce robust and accurate mechanical support and alignment structures for the PADLs, with minimal acoustic distortion and interchannel coupling. The 16 optical-fiber PADLs, each with a different time delay, were arranged to form one input port and two output ports. A handheld PADL probe was constructed using two single-element transducers and two data acquisition channels (equal to a channel reduction ratio of 8∶1). Photoacoustic (PA) images of a black-ink target embedded in an optically scattering phantom were successfully acquired. After traveling through the PADLs, the eight channels of differently time-delayed PA signals reached each single-element ultrasonic transducer in a designated nonoverlapping time series, allowing clear signal separation for PA image reconstruction. Our results show that the PADL technique and the handheld probe can potentially enable real-time PAT, while significantly reducing the complexity and cost of the ultrasound receiver system.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acoustics / instrumentation*
  • Elasticity Imaging Techniques / instrumentation*
  • Equipment Design
  • Equipment Failure Analysis
  • Fiber Optic Technology / instrumentation*
  • Image Enhancement / methods
  • Miniaturization
  • Phantoms, Imaging
  • Photoacoustic Techniques / instrumentation*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tomography, Optical / instrumentation*