Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article


Master of Science


Biomedical Engineering


Dr. Elvis C.S. Chen

2nd Supervisor

Dr. Terry Peters



Stereotactic Image-Guided Surgical Navigation System (IGSNS) supports percutaneous procedures by using medical imaging and tracking information, to assist the surgeons in the preprocedural planning and intraprocedural steps. This thesis describes the development of a stereotactic IGSNS for percutaneous liver tumour ablation, the goal of which is to assist in positioning the tip of the ablation applicator accurately to ensure complete tumour coverage. The main system improvement is the employment of a mini stereotactic patient-attach aiming device that is used as a pointer to ensure needle tip position prior to needle insertion. The thesis chapters describe the development and validation of the components of the stereotactic IGSNS. An anthropomorphic phantom development for validation and training is also presented. We hypothesize that the combination of spatial tracking, real-time ultrasound, mechanical stabilization provided by the mini-stereotactic device and image-to-image registration will improve the targeting accuracy for the focal treatment and reduce the needle repositioning.

Summary for Lay Audience

Liver cancer is one of the most common cancers around the world. One common treatment, besides surgical resection or liver transplantations, is tumour ablation. Liver tumour ablation consists in eliminating all the malignant cells of the tumour, without having to extract a part of the organ. This procedure can be done via open surgeries (the liver is exposed prior to inserting the ablation needle) or percutaneously (the ablation needle is inserted through a small incision on the skin). In either case, for the liver tumour ablation procedure to be considered successful, the needle tip needs to be placed at the center of the tumour, so that the ablation zone covers the entire volume of the tumour. A Stereotactic Image-Guided Surgical Navigation System (IGSNS) is a platform that assists surgeons during percutaneous procedures. Stereotactic IGSNSs use medical images such as ultrasound or computer tomography to visualize structures and organs and to navigate the surgeons during these procedures. In this thesis, the development of a Stereotactic IGSNS for percutaneous tumour ablation is presented. The main improvement of our Stereotactic IGSNS is the employment of a mini patient-attach needle guider that is used as a pointer. The needle guider projects a virtual line to show the needle path before insertion, ensuring an accurate needle tip position thus a successful treatment. The thesis also presents an algorithm to perform “image-to-image” registration, which is used to fuse two medical images (e.g., ultrasound and computer tomography) and ensure proper visualization of all the liver structures in a unique map. Finally, the design of a liver phantom that can be used for testing and training in the IGSNS is presented. We hypothesize that the combination of the registration of medical images and the mechanical stabilization provided by the mini needle guider will improve the process of ablation treatment and reduce needle repositioning during the procedure.