Usability Evaluation of a One-Handed Touchbased OR-Table Control

Due to the increasing number and the complexity of devices in the operation room (OR), which are caused by the diversity and variety of proprietary interface designs, the probability for use errors increases. In order to ensure a safe intraoperative workflow in the OR, integrated OR systems with central work stations have been developed. For this, there also exist concepts for handhelds, which offer touchbased graphical user interfaces (GUI). However, those come along with various limitations, e.g. possibility for one-handed interaction, which is influenced i.a. by the size, the design and the working task. Within our investigations, requirements for an enhanced concept have been gathered by taking into account corresponding standards regarding ergonomics, riskmanagement and usability-engineering. According to DIN EN 60601-2-46, machinery directive 2006/42 EG and guideline VDI/VDE 3850, the stipulated user interface has been designed in order to preselect functions on the touchscreen and their subsequent activation by physical buttons. Furthermore, the accessibility of areas of interest has been considered on the touchscreen, to avoid the re-gripping of the handheld. As a first step, the OR-table control for a tablet has been realized with Microsoft Blend, using a 22’ touch monitor. The usability study has been conducted in accordance with DIN EN ISO 9241-11 and IEC 62366. A group of ten surgeons and OR nurses underwent multiple tasks in the framework of a usability test, comparing the developed concept with a common keypad handheld. The study showed comparable results concerning the usability criteria effectiveness and efficiency. However, the concept clearly outperforms the handheld regarding user satisfaction, in particular due to the higher learnability and the easy transfer of daily-used GUI skills. The current approach motivates to develop a functional model of a touch-based handheld for OR-tables as well as with further integrated OR devices and to conduct additional usability studies