In vivo characterization of cancer using a dual imaging approach
The particular objective of this research is to consider the potential of Multispectral
Opto-acoustic Tomography (MSOT) and Optical Coherence Tomography (OCT) system to
operate in a hybrid mode. The particular aims are: to investigate the technical
feasibility of the combination of both techniques in one common front sensor device
/endoscope and examine the technical feasibility on superimposing the images generated
and matching their functional characteristics; i.e. field of view, resolution, display
of complementary contrast; To design in-vivo studies that showcase the complementarities
of utilizing the hybrid contrast offered by the two methods, and to design a strategy
on utilization of the complementary information collected, i.e. anatomical contrast
for OCT (scattering; morphological alterations) and functional and molecular contrast
for MSOT (oxy- and deoxy- hemoglobin; angiogenesis; molecular imaging via external
targeted gold nano-particles) in order to improve the diagnostic and cancer spread
assessment (staging) potential in imaging skin, colorectal and esophageal cancer.
Online GPU-accelerated Monte Carlo Research Tool for Biomedical Optical Diagnostic Needs
Accurate description of transmission and scattering of electromagnetic waves within
biological media involves the solution of the Maxwell equation for a random configuration
of scattering particles in a dielectric medium followed by averaging. This approach
forms the basis of Monte Carlo modelling of numerical simulation of photon migration
within the scattering media like biological tissues, cells cultures, polymers, liquid
crystals and others disperse media. However, the computation time and usability
have been a significant concern in all the developed Monte Carlo models. We have
developed a Monte Carlo modelling tool which allows various biomedical simulations
to be performed in browser window. On the server side, the tool is accelerated by
parallel programming on GPUs using NVIDIA CUDA technology, which guarantees delivering
the outcomes almost instantly. User friendly and reach interface provides ease of
use, brings maximum flexibility of optical system parameters, settings and delivers
results of the modeling in a typical journal paper format. To find out more, follow the link.
We use the fundamental properties of light (such as polarization and coherence)
to identify and understand interaction of light and cell's organelles. Strong multiple
scattering of light is typical for most biological tissues and leads to the loss
of initial polarization, direction, phase, and wave-front of incident optical radiation.
Circular polarization survives more scattering events than the direction of its
propagation, whereas the helicity of backscattered optical radiation depends noticeably
on the size of scattering particles. We show that the helicity flip of circular
polarized light can be observed experimentally in the tissue-like media and that
it is sensitive to the direction of light propagation. The flip in helicity is clearly
seeing as the polarization vector traverse of the Q–U plane of the Poincar´e sphere.
It has been also demonstrated that the polarization changes induced by optical clearing
can be clearly observed and analyzed quantitatively by tracking the polarization
vectors on the Poincar´e sphere (see details in the reference).
Coherent effects of scattered laser light for advanced tissue diagnostics
Coherence is a fundamental property of laser light that has been attracting great
attention e.g. by NASA and European Space Agency. In this study we are developing
a new approach for advanced diagnostics of biological tissues through the manipulation
of the coherent properties of light. The developed technique will provide sensitivity
and accuracy that cannot be assessed by other optical diagnostics modalities, including
OCT, confocal microscopy, optical/fluorescence spectroscopy, etc.
Optical Diagnostics: application for functional non-invasive brain imaging
We aim to develop an optical-based tool for functional brain imaging, neuro-imaging
diagnostics and investigations of brain activities. This tool has the potential
to be sensitive to fast changes of oxy- and deoxy- hemoglobin and the blood flow
malformations on a time scale of milliseconds. New information about the neural
activity will be provided alongside the simultaneous monitoring of hemodynamic and
behavioural changes that occur with task performance of experimental protocols applied
and tested in previous studies. The hemodynamic measure influenced by neuronal activity
across multiple cortical columns will be essential to define efficacy of therapeutic
Characterization of tumor vascular network using a multi-mode imaging approach
We aim to develop a multi-mode imaging approach utilizing a combined use of Fluorescence
Intravital Microscope (IVM), Dynamic Light Scattering Imaging (DLSI) and Photo-Acoustic
Tomography (PAT) for in vivo characterization and visualization of tumor and tumor
vascular network in the dorsal skin fold window chamber in mouse.
Multi-modal imaging for structural and functional characteristics of primary cilia
This project aims to apply a hybrid combination of cutting edge imaging modalities
such as polarization-sensitive Optical Coherence Tomography (OCT) and two-photon
fluorescence (TPF to elucidate the role of primary cilia in tissue and organ development.
We are specifically examining the role in transmitting directional cues to collagen
deposition that impact epithelial cell growth and polarisation and the development
of cartilage, bone and tendon.
e-Melanoma Database, a tool for study and research
We aim to develop an e-Melanoma database to provide high quality images of melanomas,
which could significantly enhance dermatology training in the Medical Schools. The
database can be used as a platform for development of CME courses and GPs training,
enhancement of public knowledge, and development of technical and computer-based
skills for acquiring medical knowledge. The developed e-Mel database could also
be used as a reference database for medical researchers and post-graduate students,
and could be linked with the Melanoma Foundation and/or MelNet websites for broader
access of non-university users, including overseas subscribers. This e-Mel database
could provide post-graduate medical professionals with the tools to detect melanoma
skin cancer earlier, leading to better clinical outcomes.
The e-Melanoma Database is available at http://e-melanoma.otago.ac.nz/
Optical diagnostic test of stress conditions of aquatic organisms and evaluation monitoring of fresh water ecosystem and climatic changes
A global climate change has become a dire reality and its impact is expected to
rise dramatically in the near future. Combined with the day-to-day human activities
the climatic changes heavily affect the environment. In particularly, a global temperature
increase accompanied by a number of anthropogenic chemicals falling within the freshwater
ecosystem result a dramatic enhance of the overall stress for most of aquatic organisms.
This leads to a significant shift in the species inventory and potential breakdown
of the water ecosystem with severe consequences for local economies and water supply.
In order to understand and predict an influence of climatic changes on the physiological
and biochemical processes that take place in living aquatic organisms we explore
the application of Optical Coherence Tomography, Photo-Acoustic Tomography, optical
spectroscopy and array of environment-sensitive fluorescent dyes for monitoring
and quantitative assessment of anti-oxidant enzymes activity in benthic amphipods
of Lake Baikal and other fresh water ecosystems. Thus, new application of Biophotonics
will meld various aspects of ecology, eco-physiology and molecular bases of cellular
The incidence of physiological and/or pathological defects in many types of fresh
produce is unacceptably high and accounts for a large proportion of waste. With
increasing interest in food security there remains strong demand to develop reliable
and cost effective technologies for non-destructive screening of internal defects
and rots, these being deemed unacceptable by consumers. It is well recognized that
the internal defects and structure of turbid media can be effectively visualized
by using Photonics-based technologies. Therefore we propose to use a new hybrid
multi-modal imaging approach for imaging the internal structure of plants and fresh
agricultural products with a view to non-invasively visualizing potential incidence
and severity of internal defects.
Optical Clearing and Tissue Optics Management
Hyper-osmotic agents (e.g. glucose, glycerol, propylene glycol, etc.) are known
to temporarily increase the transparency of topical skin tissues. Increasing skin
tissues transparency improves image contrast, depth imaging and spatial resolution
for various diagnostic techniques, including optical coherence tomography (OCT),
confocal microscopy, multi-photon microscopy, etc. Therefore we propose to do this
to address this problem.
Optical multi-sensor for express clinical diagnostics
We develop an optical diagnostic assay consisting of a mixture of environmental-sensitive
fluorescent dyes combined with multivariate data analysis for quantitative and qualitative
examination of biological and clinical samples. The performance of the assay is
based on the analysis of spectrum of the selected fluorescent dyes with the operational
principle similar to electronic nose and electronic tongue systems. This approach
has been successfully applied for monitoring of growing cell cultures and identification
of gastrointestinal diseases in humans.
Forensic modelling of backspatter from gunshot wounds
Little is known about high-velocity projectile soft tissue responses generating
backspatter (biological material expelled backwards through bullet entry holes).
Currently, crime scene investigators analyse backspatter patterns to estimate wounding
circumstances, but quantitative biomechanical understanding of backspatter generation
processes would improve court testimony. A mathematical model relating backspatter
patterning to gunshot characteristics would be a powerful forensic tool. We propose
to develop a laser-based imaging technique to observe and measure air flows around
the bullet. The technique involves the creation of a thin laser sheet traversing
an aerosol/spray in or around the object of interest. Laser light scattered from
the aerosol droplets is collected by a high-speed CCD camera. Thus, the high-speed
images of the aerosol particles’ motion along the bullet trajectory will provide
direct information about air flows. This project will characterise response components
between different bullets and backspatter patterns, and develop a multiphysics model
of the process.
The Group is located within the Department of Physics at the University of Otago in the Science III building at the north-west corner of the campus on the corner of Cumberland and St. David Streets. The office is on the first floor.
Biophotonics & Biomedical Imaging Research Group
Department of Physics
University of Otago
PO Box 56
Phone: 64 3 479 7749
Fax: 64 3 479 0964