Vision Engineering

The aim of this multidisciplinary project is to connect the physiology, vision engineering and optics of the human visual system.

The eye is a complex tissue that has to create a clear image of the outside world through a sophisticated system of biological-optical elements. This inseparability of the physiology and optical functionality of the ocular tissue is the main focus of our project. The cornea on the outermost layer of our visual system refracts the light into the eye and at the same time absorbs oxygen from the outside environment to nourish the inner avascular tissues. Behind the cornea lies the ocular lens, which changes shape to focus on the different objects at variable distances and at the same time corrects for imperfections of the other optical tissue. Since the ocular lens is not supported with a vascular feeding system and since it is not in contact with the outside world (unlike the cornea), it is entirely dependent on a multifaceted system of fluid dynamics for maintaining its physiological homeostasis. The light is finally focused on the retina, on the back of the eye, where the light-sensitive cells then convert the optical signal to an electrical pulse which can be understood by our brain. The retina has an unusually high demand of oxygen and energy, compared to other biological tissue, in order to maintain its normal functionality. This demand is met by a dense vasculature network on the back of the retina.

The vision engineering project uses a multidisciplinary approach, which takes advantage of bioengineering, optometry and ophthalmology resources here at The University of Auckland and other centres of excellence around the world. Individual components of the ocular system have been studied mathematically, anatomically, physiologically and optically. We believe that the close collaboration of clinicians and engineers gathered at The University of Auckland offers the perfect opportunity to marry different aspects of a perfect image formation system.

Here is a list of the doctoral projects related to the vision engineering project. Future doctoral candidates who are interested in any of these projects should email Dr Ehsan Vaghefi, e.vaghefi@auckland.ac.nz, for further information. Student co-operation will be required in applying for scholarships if you wish to undertake a project without identified student funding.

Retinal oxygen and energy consumption (modelling)

The retinal local consumption of the oxygen and production of CO2 is linked to the wellbeing and functionality of this tissue. Also various retinal pathologies are linked with its malnutrition and inadequate supply of oxygen and energy consumption. In this project anatomically correct 3D computational meshes of the healthy retina are being constructed, using the Optical Coherence Tomography (OCT) data. Then the Auckland Bioengineering Institute’s (ABI) open source computational platform is used to solve the detailed models of the oxygen consumption in the retina. These models are being extensively studied and published in the literature, hence a portion of this project is focused on the literature review and highlighting the relevancy and practicality of the published models. This project is in close collaboration with the Department of Ophthalmology, University of College London. There are opportunities for the successful candidate to spend some time in this internationally-recognized centre for model testing purposes.

Retinal electrical stimulation (modelling)

The conversion of the optical signals to electrical pulses is the main functionality of the retina. Almost all the retinal pathologies that could lead to blindness affect this capability in some way. In the pursuit of developing an artificial retina to restore the sight to blind patients, the electrical propagation properties of the retina are of special interest. The Australian Bionic Vision project is one of the world-leading ventures in this field. In this framework the Graduate School of Biomedical Engineering, University of New South Wales (UNSW), is developing an accurate mathematical model of the retinal electrical stimulation. This model is then to be used to predict and enhance the performance of the bionic retinal implants in the clinical setup. Recently a joint project is created to use an anatomically correct computational grid of the retina to transfer the published retinal electrical stimulation model to the ABI’s open source framework. There are funding available for the successful candidates and opportunities to spend some time at UNSW to obtain first-hand experience of retinal simulation and modelling.