A Haptic-Enabled Multimodal Interface and Framework for Preoperative Planning of Total Hip Arthroplasty

ultimodal environments seek to create computational scenarios that fuse sensory data (sight, sound, touch, and perhaps smell) to form an advanced, realistic, and intuitive user interface. This can be particularly compelling in medical applications, where surgeons use a range of sensory motor cues.1-4 Sample applications include simulators, education and training, surgical planning, and scientifically analyzing and evaluating new procedures. Developing such a multimodal environment is a complex task involving integrating numerous algorithms and technologies. Increasingly, researchers are developing open source libraries and toolkits applicable to this field such as the Visualization Tool Kit (VTK) for visualization, the Insight Toolkit (ITK) for segmentation and registration, and the Numerical Library (VNL) for numerical algorithms. Single libraries from these toolkits form a good starting point for efficiently developing a complex application. However, this usually requires extending the core implementation with new library modules. In addition, integrating new modules can quickly become confusing in the absence of a good software architecture. To address this, researchers have developed semicomplete application frameworks that can run independently, hiding the core implementation’s complexity. As such, they can be dedicated to produce custom applications.5 However, these systems form frameworks that aren’t multimodal because they don’t let us integrate different visual representations or other modalities such as haptics and speech. This has motivated research in developing truly multimodal frameworks,6 but the benefits of such integration are still largely unexplored. For the haptic modality in particular, hardware and software that can provide effective touch feedback can enhance the growth of innovative medical applications. From this rationale, the Multisense project aims to combine different sensory devices (haptics, speech, visualization, and tracking) in a unique virtual reality environment for orthopedic surgery. We developed the Multisense demonstrator on top of a multimodal application framework (MAF) that supports multimodal visualization, interaction, and improved synchronization of multiple cues. This article focuses on applying this multimodal interaction environment to total hip replacement (THR) surgery and, in particular, to the preoperative planning surgical-access phase.8 After validation, this approach will be highly relevant to other orthopedic and medical applications.