Preference elicitation: Obtaining gestural guidelines for PACS in neurosurgery

Objective: Accessing medical records is an integral part of neurosurgical procedures in the Operating Room (OR). Gestural interfaces can help reduce the risks for infections by allowing the surgical staff to browse Picture Archiving and Communication Systems (PACS) without touch. The main objectives of this work are to: a) Elicit gestures from neurosurgeons to analyze their preferences, b) Develop heuristics for gestural interfaces, and c) Produce a lexicon that maximizes surgeons’ preferences. Materials and methods: A gesture elicitation study was conducted with nine neurosurgeons. Initially, subjects were asked to outline the gestures on a drawing board for each of the PACS commands. Next, the subjects performed one of three imaging tasks using gestures instead of the keyboard and mouse. Each gesture was annotated with respect to the presence/absence of gesture descriptors. Next, K-nearest neighbor approach was used to obtain the final lexicon that complies with the preferred/popular descriptors. Results: The elicitation study resulted in nine gesture lexicons, each comprised of 28 gestures. A paired t-test between the popularity of the overall gesture and the top three descriptors showed that the latter is significantly higher than the former (89.5%-59.7% vs 19.4%, p < 0.001), meaning more than half of the subjects agreed on these descriptors. Next, the gesture heuristics were generated for each command using the popular descriptors. Lastly, we developed a lexicon that complies with surgeons’ preferences. Conclusions: Neurosurgeons do agree on fundamental characteristics of gestures to perform image manipulation tasks. The proposed heuristics could potentially guide the development of future gesture-based interaction of PACS for the OR.