Deep tissue imaging using optical wavefront shaping: a computational investigation

This is a 4-year PhD studentship is available in the UCL Department of Medical Physics and Biomedical Engineering. The successful candidate will join the UCL CDT in Intelligent, Integrated Imaging in Healthcare (i4health) cohort and benefit from the activities and events organised by the centre.

Background
Light-based biomedical imaging techniques such as photoacoustic imaging, optical coherence tomography and optical microscopy have greatly impacted both research and clinical practice. The primary reason for this is that light interacts strongly, through scattering and absorption, with biological tissues and therefore allows tissue properties to be probed quickly, safely and non-invasively. This strong interaction, however, also fundamentally limits the depth at which imaging can be performed since scattering can cause incident light to become disordered to the extent that imaging is made impossible. However, a new approach known as wavefront shaping (WFS) has been demonstrated which may allow images of optical contrast to be obtained at unprecedented depths in tissue. This is possible because the disorder induced by light scattering in tissue is not random but deterministic. WFS enables the light incident upon tissue to be shaped in a way that compensates for the disorder caused by scattering, thus allowing for light to be focussed, deep in tissue, even in the presence of strong scattering. Recent experimental work has demonstrated the feasibility of this promising technique which could revolutionise biomedical optics by enabling high-resolution optical imaging deep in tissue. However, further research into the mechanisms underlying WFS is needed in order to advance WFS from a feasibility study into a mainstream imaging tool. This need presents an exciting opportunity to work on a project at the cutting edge of biomedical imaging.

Research aims
The aim of this project is to address the need for greater understanding of the underlying physics and practical limitations of WFS through computational modelling. This will build upon existing work at UCL where the pseudo-spectral time domain method has been used to perform full wave (i.e., including phase, polarisation, multiple scattering etc.) modelling of light propagation in tissue for applications in biomedical imaging. This project will underpin the theoretical aspect of a new wavefront shaping lab at UCL and will be used to develop the lab’s experimental programme. This will enable a range of new scientific studies including predicting the performance of different state of the art approaches to WFS, establishing the practical limits of WFS in terms of its performance (e.g. focussing efficiency, speed, robustness to motion) in different tissues and examinations of the underlying physics. This is primarily a computational project with opportunities to engage in practical studies. It would suit a candidate who wants to develop rigorous computational models that are directly relevant to the development of new practical techniques for enhancing biomedical imaging within the context of a world-leading biomedical optical imaging group.

Requirements
Applicants should have a first degree in Physics or a related subject passed at 2:1 level (UK system or equivalent) or above. Knowledge of optics is required and strong computer programming skills are desirable.

To apply
Please send a CV and covering letter expressing your interest to Dr James Guggenheim ([Email Address Removed])

Application closing date: 7 June 2019