Creating new approaches for PA imaging in heterogeneous and/or moving environments

Host institution: University of Canterbury, School of Physical and Chemical Sciences

Supervision: Dr. Laura Cobus (UC)

Overview:

About our lab

We use classical waves for material characterization and imaging. We also perform fundamental research in order to better understand wave propagation through complicated materials, which helps to advance imaging and characterization through complex media. Our work involves experiments and/or numerical simulations, and close collaborations with other groups both in New Zealand and overseas.

About the Project

Most classical wave imaging (e.g. medical ultrasound, photoacoustics, optical imaging, and imaging/monitoring of industrial materials) uses sensor arrays (a collection of many sensors which can emit and receive independently) to record a set of signals. The main challenge is how to then use this large dataset in a clever way to gather `hidden' information about the medium, and in particular, how to make accurate images. Usually, an image is calculated based on an assumption that the medium is homogeneous; however, when this hypothesis is incorrect due to layers of muscle, fat, bone, and/or skin, the image can be distorted, resulting in missed or inaccurate medical diagnoses. We develop approaches for better imaging in such complicated environments.

In ultrasound imaging, signals are sent and received by an array of acoustic sensors placed on the skin, while in photoacoustic (PA) imaging, unfocused light illuminates an area of interest, resulting in a thermoelastic expansion of the tissue which creates acoustic waves. These waves are then detected by the acoustic sensor array and used to create an image. Achieving a superior image contrast and resolution can translate to improved outcomes for cancer, microvasculature, inflammatory and cardiac disease screening; however, compensating for the effects of tissue heterogeneity remains a serious challenge for PA imaging. Recently, however, we have been exploring a new approach to distortion correction in PA imaging, based on a family of recently-developed methods for ultrasound imaging. The proposed PhD project will use these ideas to create new approaches for PA imaging in heterogeneous (e.g. tissue+bone+blood) and/or moving environments (e.g. blood flow, tissue motion).

The candidate will be part of a small team supervised by Dr. Laura Cobus (Senior Lecturer, University of Canterbury), with collaborator Dr. Jami Shepherd (Senior Research Fellow, University of Auckland). The candidate will be based at the University of Canterbury, but will visit the University of Auckland periodically to perform photoacoustic imaging  experiments.  

Eligibility

Applicants must meet University of Canterbury entry requirements for admission to a PhD. Award of the scholarship is conditional on the university accepting your enrolment. The successful applicant will be guided through the process of formally applying for admission.  

Applicants with a background in physics, mathematical physics, or engineering will be considered. A strong undergraduate knowledge in wave physics would be an asset.

This project is based in Christchurch, New Zealand and is available for immediate start.

How to apply

To express your interest in this scholarship and PhD research opportunity, please prepare the following items:

• A brief CV including qualifications, academic achievements, list of publications, work history, and references.

• A copy of your academic transcript(s).

Please submit your application via email to the main supervisor of this project  (laura.cobus@canterbury.ac.nz) who will guide you through the scholarship application process.

‍

‍