Abstract
Funding Acknowledgements
Work supported by the NIHR i4i funded 3D Heart project [II-LA-0716-20001]
Background
3D printing is used for surgical planning of complex congenital heart disease (CHD) because it provides an intuitive 3D representation of the image data. However, the 3D print is static and it can be costly and time consuming to create. Virtual Reality (VR) is a cheaper alternative that is able to visualise volumetric images in 3D directly from the scanner, both statically (CT and MR) and dynamically (cardiac ultrasound). However, VR visualisation is not as tangible as a 3D print - this is because it lacks the haptic feedback which would make the interactions feel more natural.
Purpose
Evaluate if adding haptic feedback (vibration) to the visualisation of volume image data in VR improves measurement accuracy and user experience.
Method
We evaluated the effect of vibration haptic feedback in our VR system using a synthetic cylinder volume dataset. The cylinder was displayed in two conditions: (1) with no haptic feedback, and (2) with haptic feedback. Ten non-clinical participants volunteered in the evaluation. They were blinded to these two test conditions. The participants were asked to measure the cylinder’s diameter horizontally and vertically, and its length, in each test condition. The measurement results were compared to the ground truth to assess the measurement accuracy. Each participant also completed a questionnaire comparing their experience of the two test conditions during the experiment.
Results
The results show a marginal improvement of measurement accuracy with haptic feedback, compared to no haptics (see Figure a). However, this improvement was not statistically significant. The haptic feedback did improve the participants’ confidence about their performance and increased the ease of use in VR, hence, they preferred the haptics condition to the no haptics condition (see Figure b). Moreover, although 70% of the participants reported relying on the visual cue more than on the haptic cue, 90% found that the haptic cue was helpful for deciding where to place the measurement point. Also, 88.9% of the participants felt more immersed in the VR scene with haptic feedback.
Conclusion
Our evaluation suggests that although haptic feedback may only marginally improve measurement accuracy, participants nevertheless preferred it because it improved confidence in their performance, increased ease of use, and facilitated a more immersive user experience.
Abstract P1566 Figure.
Haptic feedback is more important than VR experience for the user experience assessment of in-car human machine interfaces
