Evaluation of Pseudo-Haptic Interactions with Soft Objects in Virtual Environments

Abstract

This paper proposes a pseudo-haptic feedback method conveying simulated soft surface stiffness information through a visual interface. The method exploits a combination of two feedback techniques, namely visual feedback of soft surface deformation and control of the indenter avatar speed, to convey stiffness information of a simulated surface of a soft object in virtual environments. The proposed method was effective in distinguishing different sizes of virtual hard nodules integrated into the simulated soft bodies. To further improve the interactive experience, the approach was extended creating a multi-point pseudo-haptic feedback system. A comparison with regards to (a) nodule detection sensitivity and (b) elapsed time as performance indicators in hard nodule detection experiments to a tablet computer incorporating vibration feedback was conducted. The multi-point pseudo-haptic interaction is shown to be more time-efficient than the single-point pseudo-haptic interaction. It is noted that multi-point pseudo-haptic feedback performs similarly well when compared to a vibration-based feedback method based on both performance measures elapsed time and nodule detection sensitivity. This proves that the proposed method can be used to convey detailed haptic information for virtual environmental tasks, even subtle ones, using either a computer mouse or a pressure sensitive device as an input device. This pseudo-haptic feedback method provides an opportunity for low-cost simulation of objects with soft surfaces and hard inclusions, as, for example, occurring in ever more realistic video games with increasing emphasis on interaction with the physical environment and minimally invasive surgery in the form of soft tissue organs with embedded cancer nodules. Hence, the method can be used in many low-budget applications where haptic sensation is required, such as surgeon training or video games, either using desktop computers or portable devices, showing reasonably high fidelity in conveying stiffness perception to the user.

Survey of Pseudo-Haptics: Haptic Feedback Design and Application Proposals

“…1) Displacement: The first approach visualizes the distorted displacement of user input D 0 (Fig. 2(a)) [29]- [34], [36]- [40], [88]. L ecuyer et al [29] asked users to push their thumb on a piston mounted on a passive spring, and they viewed the distorted thumb displacements D 0 on the display.…”

“…Li et al [36], [38], [88] proposed a surgical training system that used pseudo-haptics for tumor identification during palpation. They proposed presenting the hardness of the tumor using pseudo-haptics on soft tissue surfaces.…”

Editorial: ViTac: Integrating Vision and Touch for Multimodal and Cross-Modal Perception

“…Haptic information can also be conveyed to a user during teleoperation tasks in the form of visual cues. This cross-modal sensation between visual and tactile sensing is usually termed pseudo-haptics (Li et al, 2016). In "Proposal and Evaluation of Visual Haptics for Manipulation of Remote Machine System" by Haruna et al, this approach is assessed using electroencephalogram (EEG) data on a Virtual Reality (VR) setting.…”

The Impact of Control-Display Gain in Kinesthetic Search

“…The results suggest that applying a high CD gain can help reduce task completion time [9,10]. In the context of kinesthetic interactions, some studies suggested that the visual feedback provided by different CD gains can influence kinesthetic perception and sometimes even override the perception available through force feedback [11][12][13]. Further, while using a force-feedback device, applying a large CD gain leads to a mismatch between hand motions and HIP motions, which thus could potentially influence the user's control of the HIP.…”