Biomedical Imaging and Sensing

Andrei Zvyagin

Centre for Biophotonics and Laser SciencePhysics, School of Physical SciencesBiomedical Engineering, School of Information Technology and Electrical Engineering

The University of Queensland

Projects

Coherence-domain imaging techniques, as applied to cells and live biological tissueFull-field Fourier domain optical coherence

tomography (3F-OCT)Synthetic-aperture confocal microscopy

Dialysis-assisted fibre optic spectroscopy for drug sensing in situ

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Full-field Fourier domain OCT

Digitalsensor

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ect

Sweptsource

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Fourierlens

f f

Coupler

•3D-data cube is acquired•Contains comprehensive information on the sample 3D structure and

its optical scatter•Signal-to-noise ratio is optimized•Suitable for ophthalmology applications in vivo•Relies on rapid broadly-tuneable laser swept-source

Dialysis-assisted fibre optic spectroscopy

Fluorophores

Tissue constituents

Illumination To spectrum analyzer

Setup for measuring fluorophore concentration in tissue using DAFOS. Inset, DAFOS sampling head. Illumination light guided through a fibre F, is emerging from the dialysis membrane DM, tip.

Illumination fibre

Microdialysis membrane

Tissue

Collection fibre

Needleibre

F

DM

•Small molecules, e.g. drugs, enter the

sampling head and detected

spectroscopically•Compared with traditional microdialysis

tool, DAFOS is rapid•The equilibrium between the solute and

intercellular fluid is established via

diffusion, DAFOS is potentially sensitive

and reliable• The use of high-fluence UV radiation is

now possible, as DAFOS can be light-

tight, and prevents large protein

complexes from entering the sampling

head• Enables in vivo applications of a range

of spectroscopic techniques

DAFOS

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Time response of DAFOS signal

Setup for measuring fluorophore concentration in tissue using DAFOS. Inset, DAFOS sampling head. Illumination light guided through a fibre F, is emerging from the dialysis membrane DM, tip.

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1min, , PODLc MM

The preliminary numerical simulations considering existing tapering technology. The ultimate sub-nM sensitivity ,

Lize et al., Opt Expr 12 (2004)

Tong et al., Nature 426 (2003)

Centre for Ultra-high Bandwidth Devices for Optical Systems (CUDOS)

Absorption DAFOS