Use of acousto-optic tuneable filters for imaging fluorescence spectroscopy applications in vivo and in vitro

Mounir Bouhifd, Maurice P. Whelan, Marc Aprahamian

Research output: Contribution to journalConference articlepeer-review

2 Scopus citations


We describe the design and development two prototype spectroscopy imaging instruments based on custom-made acousto-optic tuneable filters (AOTF). These devices can be coupled to many standard imaging systems (e.g. an endoscope or a fluorescence microscope). The instruments developed offer significant advantages over typical fixed-filter imaging systems in terms of flexibility, performance and diagnostic potential. Any filtering wavelength in the visible range can be rapidly selected either by random access or continuous tuning. Since filtering is achieved through a diffractive process, an excellent signal-to-noise ratio is achieved that allows the detection of extremely low fluorescence signals such as autofluorescence. These adapters were designed to allow the simultaneous imaging of both the filtered and unfiltered signals, A first prototype instrument was developed and demonstrated for in-vivo applications. When attached to the eyepiece of a commercial endoscope, it allowed the simultaneous white light endoscopy and fluorescence imaging. Autofluorescence of protoporphyrin IX (PpIX), an endogenous chromophore that traces early-stage diseased tissue experiencing an inflammatory response, was mapped in vivo on a rat model. The system has also been approved for medical use and human clinical trials are underway. In addition, we are currently testing a second AOTF module for in vitro applications. This new AOTF adapter was designed to be coupled to the viewing port of a commercial fluorescence microscope to realise a fluorescence imaging spectrometer capable of detecting and mapping fluorescent biomolecules.

Original languageEnglish (US)
Article number03
Pages (from-to)11-20
Number of pages10
JournalProgress in Biomedical Optics and Imaging - Proceedings of SPIE
StatePublished - 2005
Externally publishedYes
EventAdvanced Biomedical and Clinical Diagnostic Systems III - San Jose, CA, United States
Duration: Jan 23 2005Jan 26 2005


  • AOTF filtering
  • Autofluorescence
  • Endoscopy
  • Fluorescence imaging
  • Microscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging
  • Biomaterials


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