Computational Modelling team

Ultrasound-mediated treatment of blood clots

Thrombosis remains a leading cause of cardiovascular mortality globally. Sonothrombolysis has emerged as a promising non-invasive alternative that utilises ultrasound waves to excite microbubbles to enhance blood clot lysis. Achieving precise parameter optimization and complete mechanical destruction of the targeted thrombus is paramount to prevent incomplete recanalization and localized vascular damage. One of the key focal points of our research is utilizing multiphysics computational modeling and simulation to systematically evaluate how ultrasound and microbubble parameters influence bubble cavitation and flow-induced shear stress on the clot surface. Through these in silico investigations, we aim to deliver fundamental insights into microbubble-clot mechanical interactions, which will directly guide clinical decision-making and optimize treatment protocols.

Figure: (Left) Insertion of intravascular ultrasound transducer to treat deep vein thrombosis. (Middle) Development of macroscale model (Right) Microscale model of sonothrombolysis.

Transdermal drug delivery via acoustic sonophoresis

Transdermal drug delivery offers a highly advantageous, non-invasive alternative to oral administration and conventional hypodermic injections. However, the stratum corneum—the skin's outermost lipid barrier—strictly limits the penetration of most therapeutic compounds. Sonophoresis has emerged as a promising technique that utilizes ultrasound waves to transiently alter skin permeability and enhance macromolecular transport. Achieving predictable drug flux without causing deep tissue damage or severe localized heating is crucial to ensuring clinical safety and efficacy. We develop predictive simulation frameworks to analyse acoustic streaming mechanics and transient pore generation, aiming to maximize molecular flux during transdermal delivery.

Thermal ablation treatment of cancer

Cancer is one of the leading causes of death worldwide. Thermal ablation techniques are among the well-established methods for treating small cancer. Examples include radiofrequency ablation (RFA), microwave ablation and cryoablation. A successful thermal eradication of the cancer tissue is important to prevent recurrence of tumour. One of the research studies that we do is to use computational modelling to help improve the understanding of the thermophysics of the treatment mechanisms in order to facilitate the design and optimisation of the treatment protocol.

Figure:  (Left) Model of the reconstructed patient liver (Mid) Streamlines of the electric field distribution (Right) Iso-surfaces depicting the temperature distribution achieved during treatment

Mass transport in biological tissues 

Fluid transport in biological tissues plays an important role in several medical treatments, such as drug delivery and saline-infused radiofrequency ablation (RFA), among others. A good understanding of how fluid flows inside tissues can help to further understand the effectiveness of these medical treatments. We couple experimental studies on ex vivo tissues with computational modelling to explore the complex mechanisms involved in the transport of fluid in biological tissues.

Figure: (Left) Ex vivo fluid infusion study on goat liver. (Right) Stained regions of the tissue indicating flow distribution.

Non-invasive disease detection 

Although biopsy remains the gold standard in the diagnosis of the majority of the diseases out there, the process is slow and not without complications.  Non-invasive detection of medical abnormality helps to minimize the complications often associated with biopsy. These techniques, which can be based on ultrasound elastography, infrared thermography etc, can be used as a preliminary screening tool for mass screening exercises to determine if further diagnosis based on tissue biopsy is required of the patient. This reduces not only the waiting time, but also the cost involved. Computational modelling helps to improve the accuracy and reliability of the detection by providing accurate description of the physics/mechanisms during the detection process.

Figure: (Left) Model of the transducer array in a curved ultrasound probe. (Mid & Right) pressure and acoustic radiation force (ARF) distribution to facilitate shear wave elastography

Dr Ooi Ean Hin

Dr Ooi heads the Computational Modelling team of the Biomedical Engineering research group. He is a Senior Lecturer in the School of Engineering, Monash University Malaysia. He obtained his Bachelor’s degree in Mechanical Engineering from University of Technology, Malaysia and his Doctor of Philosophy from Nanyang Technological University, Singapore. His research experience includes research positions in the School of Clinical and Experimental Medicine, University of Birmingham, Wessex Institute of Technology and the Institute of Biomedical Engineering, University of Oxford. He is a technical consultant for Ascend Technologies Ltd, United Kingdom and is the Associate Editor of the Journal of Medical Imaging and Health Informatics.

His primary research interests are to use mathematical and computational modelling to understand different biophysical and physiological phenomena related to thermal treatment of cancer and tissue biomechanics. He also retains an interest in the development of mesh reduction numerical methods.

Research Team

Dr Tan Zhi Qi

Dr Tan obtained his Bachelor’s and PhD in Mechanical Engineering from Monash University Malaysia, where he is now a lecturer in the Common Engineering department. His research leverages computational modelling to address multiphysics problems in biomedical applications, specifically in ultrasound-mediated therapies. His primary work involves the computational modelling of sonothrombolysis, where he investigates how acoustic cavitation enhances thrombosis treatment. His contributions to the field have earned him the Best Paper Awards from both the IEEE-EMBS and the Asia-Pacific Society for Artificial Organs (APSAO). Dr Tan is currently expanding his research into ultrasound-assisted drug delivery and other emerging applications of therapeutic ultrasound.

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Current GRS

Ms Alexis Nguoy Lamn Mak

Alexis graduated from  University of Nottingham with a Master Degree in Mechanical Engineering in June 2015. Following that, she worked as a Technical Support Engineer in Panasonic Malaysia. She has a  strong interest in research in the field of Biomedical Engineering. She is currently pursuing her doctoral studies in the School of Engineering, Monash University Malaysia, where she will explore the mass transport phenomena in biological tissues with application in thermochemical ablation.

Mr William Tze Hau Lim

William graduated with a First Class Honours in Bachelor of Mechanical Engineering (Honours) degree from Monash University in April 2020. He is listed in the Faculty of Engineering Dean’s Honour List and was also a recipient of Monash High Achiever Award. William joins the BEMS group as a PhD student in December 2020. His research focuses on uncovering and elucidating the underlying biomechanical principles involved in the application of ultrasound shear wave elastography for detecting changes in renal tissue stiffness due to the progression of chronic kidney disease.

Mr Jason Kin Kit Cheong

Jason obtained  his Bachelor Degree in Mechanical Engineering in Monash University Malaysia in 2018. He was first exposed to biomedical engineering during his final year project - on investigating the influence of electrode lengths on the single probe bipolar radiofrequency ablation of the liver. He has since developed an interest in the biomedical engineering field.  He was a Research Assistant with BEMS from 2018 to 2019. He is currently pursuing his Master's degree in the School of Engineering, Monash University Malaysia, where he investigates the feasibility of gold nanorods for the thermal treatment of cancer

Alumni

Dr Antony Seng Kai Kho

Antony joined the School of Engineering, Monash University Malaysia as a PhD student in 2018. He graduated with First Class in Master in Engineering in Mechanical Engineering with Honours from University of Nottingham. With research interests in bio-fluid mechanics and mathematical modelling, he joined the BEMS group to investigate the role of saline in enlarging the thermal coagulation zone during saline-infused RFA. He successfully completed his PhD studies in October 2021.

Dr Chai Yee Loke

Chai Yee joined the School of Engineering, Monash University Malaysia as a PhD student in 2015 under the supervision of Dr Ooi.  She graduated with a Bachelor of Engineering in the discipline of Mechanical Engineering with Honours from Tun Hussein Onn University of Technology, Malaysia in 2006. Her research focuses on the development of a 3D human eye model using COMSOL Multiphysics for computational fluid dynamics (CFD) and structural mechanics analyses associated with the pathogenesis of glaucoma.  Chai Yee successfully completed her PhD studies in February 2019 following the submission of her revised thesis to the university. She is currently a Senior Lecturer in the Faculty of Engineering and Technology, Tunku Abdul Rahman University College.

Ms Shelley Yap

Shelley graduated with a Bachelor's Degree in Mechanical Engineering from Monash University. She was a part of the BEMS group in 2017, when she did her final year project. In 2018, she joined the BEMS group to pursue her Master in Engineering Science (Research), where she explored the practicality of bipolar and multipolar radiofrequency ablation for treating liver cancer. In 2020, Shelley successfully completed her Master studies following the submission of her thesis to the university. She is currently working as a Research Engineer in Huawei Technologies.