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.

Light-tissue interaction

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).

Figure is adopted from our paper

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.

Figure is adopted from Dr Igor Meglinski's presentation

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 innovations.

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.

Figure is adopted from our paper

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 stress tolerance.

Figure is adopted from our paper

Plant Photonics

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.

Figure is adopted from our paper

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.

Figure is adopted from our paper

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.