Surgeon-friendly 3D Navigation

Abstract

Hepatopancreato-biliary (HPB) surgeons, when planning complex cases of pancreatic cancer, lose precious time because of difficulties in visualising the interaction between tumour and blood vessels and identifying patient-specific anatomy. To tackle this issue, the Integrated Imaging Workstation (IIW) was prototyped by e/MTIC and Philips. This prototype encompasses a conventional medical viewer and a holographic display to visualise the same medical data, providing a functional basis and showing promise. However, it lacks a human-centred interaction design, particularly in integrating it into a surgeon’s established interaction flows with conventional medical imaging, as a study with 13 expert surgeons highlights. The literature review and empirical research show that surgeons iteratively scroll through scans to build a mental 3D reconstruction of the anatomy, and have two personal approaches to finding anatomical landmarks and interactions, “vertical scan” and “zoom in and out”. Also, it unveils 3 key design opportunities: minimising workflow disruption, visualising both overview and detail and balancing speed and control in the interaction.

These findings were translated into multiple design concepts, such as one with different modes of visualisation depending on anatomical landmarks. The most desirable concepts were combined into a navigation system, which in turn went through one expert feedback iteration. The final design comprises a system for surgeons to easily select anatomical landmarks through 2D medical imaging. This enables reaching and controlling desired points of view, which then can be orbited around. A high-fidelity prototype was implemented with Unity3D and evaluated. The mixed-method evaluation study with 3 expert HPB surgeons shows promise towards the overall usability of the navigation system and its clinical application. However, some aspects of the interaction, such as the selection of minor vessel branches and missing visual feedback for point-of-view changes, need refinement. These results illustrate a solid human-centred design direction for supporting surgeons in finding crucial landmarks and vascular interactions, as well as an approach to integrate 3D medical visualisation into established workflow with 2D imaging of HPB surgeons.

This thesis hopes to be a starting point for future iterations of the IIW. For example, using metaphors to help the surgeons establish a mental model of the 3D camera system could be tested, or scoping the main user focus to novice surgeons could be helpful to refine the design. Furthermore, this project could be relevant for other research and design endeavours that aim to inject 3D medical visualisation technology into existing workflows in a surgeon-friendly manner.