Since 2007, our research group has been developing a new type of imaging probe: a microscope-in-a needle.
This is a miniaturized optical imaging probe, encased in a medical needle, capable of taking high resolution scans deep inside the body.
One of the group's main interests is the medical imaging technique of
optical coherence tomography.
Like ultrasound, OCT images are corrupted by speckle, which can be
static or moving. Moving speckle is known to be useful, but we have
shown that even static speckle may contain useful information.
Resolution at the micron level is called ultrahigh-resolution OCT.
Limits on what can be attained are set by various phenomena. We have
been particularly interested in the fundamental limits set by
dispersion and absorption in tissue.
Our interest in elastography is to measure the elastic properties of tissue using OCT systems.
We are investigating use of optical coherence tomography (OCT) for examining skeletal muscle tissue of animal models of muscle damage.
Our interest in coherent optical techniques extends to a branch of
holography, Fourier holography. We are using
single digital holograms to characterise microstructure in
biological samples over large fields of view.
A new superresolution approach allows us to spectrally encode a sample's spatial frequencies and decode them by wavelength demultiplexing.
This generates an instant direct relationship between structure size and detected wavelength.
Our interests in microscopy have led us to also become interested in
fluorescence and other nonlinear optical microscopy techniques, as
well as how deep tissue imaging may be improved in general.
This research extends OCT usage to endoscopic scanning of large-scale
hollow organs. Specifically, we have developed an endoscopic OCT probe
to map the 3-D shape and dynamics of the upper airway, including during
sleep, for sleep apnoea research.
We have also actively investigated diffuse light propagation in skin
motivated by early in vivo detection of melanoma. We have mainly
studied fibre-optic probes based on the diffuse reflectance
spectroscopy of white light.
In carrying out our research, we have built a lot of instruments
comprising optical assemblies, photonic circuits, electronics, data
acquisition and display systems, some of which are featured here.