Posters by day

The following is the list of the poster presentations for the conference sessions by day.
Overview of the programme can be found here.

POSTERS 1, Tuesday, July 5
005 A Study on Control of a Phantom Sensation by Visual Stimuli Arinobu Niijima, Takefumi Ogawa In this paper, we present a notable study to control occurrence of a phantom sensation by visual stimuli. A phantom sensation is one of tactile illusion caused by vibration stimuli. Some previous works employed vibration motors for a tactile display, and utilized a phantom sensation to present tactile stimuli in a large area with a few vibration motors. However, there are few studies to investigate the influence of visual stimuli on a phantom sensation. Our previous works showed that visual stimuli influenced localization of vibrotactile perception. From the results, we considered that visual stimuli also influence on a phantom sensation. We made a visual-tactile display, and conducted some experiments. The results showed that visual stimuli influenced a phantom sensation and it seemed to be possible to control the occurrence of a phantom sensation by changing visual stimuli.
006 Multilateral Teleoperation with Measured Force Feedback: A Model-Free Approach Michael Panzirsch, Thomas Hulin, Jordi Artigas-Esclusa, Christian Ott, Ferre Manuel In teleoperation systems, the master robot receives force feedback from the remote slave side. Thus, the human operator can perceive the contact between the slave robot and its environment. Application of a force sensor at the slave robot improves the performance of the telepresence system in terms of transparency. Still, so far no approach allowing measured force feedback in time delayed multilateral systems that allow the interaction of multiple agents can be found in literature. To this end, this paper presents a multilateral setup with measured force feedback based on the time domain passivity approach. Higher transparency compared to other time invariant and model based approaches can be obtained for both bilateral and multilateral systems. Experiments are presented to allow for a performance analysis of the proposed system design.
007 Enhancement of Virtual Simulator for Maritime Crane Operations via Haptic Device with Force Feedback Yingguang Chu, Houxiang Zhang, Wei Wang This paper presents simulations of maritime crane operations using a haptic device with force feedback. Maritime crane operations are challenging under adverse environmental conditions. System testing and operation training on physical systems and prototypes are time-consuming and costly. Simulation of crane operations in virtual environment alleviates the shortcomings with physical systems by 3D visualization and force feedback to the operator. Cur-rently, haptic technology has limited applications in heavy industries due to the system stability and safety issues related to remote control of large manipulators. A novel 6-DoF haptic device was developed for crane operations enabling a larger workspace range and higher rigidity. The employment of the haptic device enlarges the human interaction scope of the virtual simulator for crane operations by sending feedback forces to the operators. Simulations of maritime crane anti-sway control suggested that the load sway time and amplitude were reduced more effectively with force feedback. Using the haptic device, it also helps the crane operator to prevent problematic operations.
009 A Novel Haptic Stylus for Mobile Terminal Lei Tian, Aiguo Song, Dapeng Chen Haptic interaction is a new interactive function in human-computer interaction of mobile terminal.  In this work, we present a novel haptic stylus for mobile terminal, which can achieve haptic display of visual image.  The haptic stylus generates force feedback and tactile feedback through electromechanical structure and piezoelectric ceramics. In order to obtain the haptic information of image, we adopt shape from shading (SFS) algorithm to extract height information of image, which is presented in the form of force feedback. And fractional differential method is used to extract edge information of image, which is expressed in the form of tactile feedback. The software system of haptic interaction is developed based on Android system. And the mode of communication is Bluetooth. Finally, the haptic perception experiment is conducted to investigate effect of perception with different mode of haptic interaction.
015 Texture Rendering on a Tactile Surface using Extended Elastic Images and Example-Based Audio Cues Julien Fleureau, Yoan Lefevre, Fabien Danieau, Philippe Guillotel, Antoine Costes A texture rendering system relying on pseudo-haptic and audio feedback is presented in this paper. While the user touches the texture displayed on a tactile screen, the associated image is deformed according to the contact area and the rubbing motion to simulate pressure. Additionally audio feedback is synthesized in real-time to simulate friction. A novel example-based scheme takes advantage of recorded audio samples of friction between actual textures and a finger at several speeds to synthesize the final output sound. This system can be implemented on any existing tactile screen without any extra mechanical device.
024 An IMU and RFID-based Navigation System Providing Vibrotactile Feedback for Visually Impaired People Claudio Loconsole, Maryam Banitalebi Dehkordi, Edoardo Sotgiu, Marco Fontana, Massimo Bergamasco, Antonio Frisoli This paper presents the DOVI (Device for Orientation of the Visually Impaired) system, a new inertial and RFID-based wearable navigation device for indoor environments providing vibrotactile feedback to visually impaired people for reaching a target place. The DOVI system is based on sensor fusion techniques, allowing a precise and global localization of the pedestrian thanks to both inertial measurements from accelerometers and gyroscope and passive RFID tags. The pedestrian is provided haptic feedback through a vibrotactile bracelet, that can guide him/her through the correct path toward the target. The DOVI system is complementary to those system which allow the detection of mobile obstacles along the path and to other aids, such as the white cane or the guide dog.
026 Illusion of wet sensation by controlling temperature and softness of dry cloth Mai Sibahara, Katsunari Sato In order to create a device that produces the sensation of wet cloth, we have proposed a method to augment the wet sensation of dry cloth. This paper investigated whether controlling the surface temperature and softness of a cloth could reproduce the wet sensation or not. Participants scored their feelings after touching cloth with different temperatures and softness. Results indicate a tendency to perceive a wet sensation equivalent to actual wet cloth by not only decreasing the temperature but also increasing softness of the cloth.
027 How attention is allocated when using haptic touch: Shape feature distinction and discrimination strategy Toro Graven This study investigated how attention is allocated by the physical distinction between tactile 2D shape features: Part 1 tested whether certain shape feature distinctions are perceived efficiently (pre-attentively), as opposed to inefficiently (attention dependent). Part 2 explored what discrimination strategies are at use, and with what level of attention (from pre to focused). It was found (Part 1) that the straight line ↔ angle distinction and the curve ↔ straight line distinction are perceived pre-attentively; the angle ↔ curve distinction attention dependent, and (Part 2) three discrimination strategies; the figure identity strategy, the global characteristics strategy and the touch vision strategy. The first has three levels, the latter two have two levels of attention; the first ranked a feature conjunction, the latter two ranked one separate feature as the most important. Despite this, no statistically significant difference was found between the discrimination strategies; on exploration time, accuracy, and after-decision certainty.
036 It’s all about the Subject – Options to Improve Psychometric Procedure Performance Christian Hatzfeld, Viet Quoc Hoang, Mario Kupnik We investigate the effect of procedure-specific parameters on the performance of three common psychophysical procedures. Methods considered include transformed-staircase procedures, the Ψ-method and the UML method, while performance is evaluated in terms of accuracy, efficiency, precision and robustness. Simple Yes/No- and three alternative forced choice response paradigms were considered. A Monte Carlo simulation was conducted for three different types of test persons and analyzed by analysis of variances. Results show a large effect of the test person on the performance, especially for staircase procedures. No parameter exhibited a relevant effect on accuracy for each analyzed methods, estimation precision can be increased with an increasing number of trials. Only for staircase procedures, efficiency can be influenced by the choice of the progression rule.
038 Does haptics improve learning and recall of spatial information? A study using a virtual reality Nasendoscopy Simulation Greg Ruthenbeck, Michael Tlauka, Andria Tan In the literature, haptic training has long been regarded as an effective means of acquiring skills that involve force feedback. This is relevant in the context of haptic virtual reality applications that argue that the addition of haptics increases the effectiveness of the training system. Here we describe an experimental investigation which examines whether haptic feedback increases people’s spatial knowledge of a simulation. In particular, we address the following question: Is visuo-haptic interaction a more effective way of learning spatial information than purely visual interaction? A comparison of two groups of participants (visual versus visuo-haptic) revealed no significant differences in their spatial knowledge of the simulation. The findings are discussed with reference to potential variables which may affect spatial learning such as cognitive load. Research question: Does haptics improve learning and recall of spatial information? Conclusion: No definitive evidence was found for improved recall of spatial information learned using visuo-haptic feedback relative to visual feedback alone. Further research using more complex simulations is needed to better understand the significance of haptics on the learning and recall of spatial information.
041 Perceived intensity of vibrotactile stimuli : Does your clothes really matter? Valérie Duthoit, Jean-Marc Sieffermann, Eric Enrègle, David Blumenthal Vibrotactile is a modality of growing interest for everyday interfaces including for car interfaces. It can be employed to many applications like lane departure warning, collision warning, notications etc. But interfaces that are not directly in contact with the user’skin must deal with his clothes. This study investigates whether clothes have a signicant effect on the perception of intensity of simple vibrotactile stimuli or not, and therefore if they have to be taken into account in the setting of vibrotactile feedback. We consider a single actuator on the back of a car seat, which was covered by a thin foam, a layer of clothes, and hidden by a black covering. Simple vibrations of 1 s. with frequency from 100 Hz to 200 Hz and three different amplitude levels were triggered. We asked 31 subjects to give a mark from 0 to 10 to assess their perceived intensity of the stimulus. Results show that perceived intensity is adversely affected by a thick winter coat, but seems to be  lightly affected by several thin layer like T-shirts. We conclude that designers do not have to consider all the variety of clothes to set the vibrations’parameters, but they must take winter coats into account if final user is supposed to wear it. Moreover, we demonstrate the ability of naive subjects to quote their perceived intensity of simple vibrotactile stimuli.
046 Affordable Wideband Sensor Coupled Vibrotactile Actuator Systems for Psychophysical Experiments Abhijit Biswas, Manivannan Muniyandi, Srinivasan Mandayam A. Generation of high-amplitude high-frequency pure-tone mechanical vibrations over a wide frequency range is required in many applications, such as Vibrotactile (VT) stimulation, material testing and so on. This paper describes development of three different types of actuator systems, pneumatic, electromagnetic and piezoelectric, towards the objective of conducting VT psychophysical experiment above 1 kHz starting from few hundreds of Hz. While the piezoelectric system offers compactness, the 120 W electromagnetic system offers wider bandwidth and is capable of generating suprathreshold stimulus even above 2 kHz. Design and response of the piezoelectric actuator system, including the custom built LVDT coupled with the actuator are detailed in this paper. The frequency response of the tested configuration remains flat over a wide bandwidth till 4 kHz, even at high level of excitation, while generating bursts of 100 µm amplitude sine waves. The developed linear charge-drive is suitable for low-current application ~50 mA, maintaining low EMI and small size.
050 Going against the grain – Texture orientation affects direction of exploratory movement Alexandra Lezkan, Knut Drewing In haptic perception sensory signals depend on how we actively move our hands. For textures with periodically repeating grooves, movement direction can determine temporal cues to spatial frequency. Moving in line with texture orientation does not generate temporal cues. In contrast, moving orthogonally to texture orientation maximizes the temporal frequency of stimulation, and thus optimizes temporal cues. Participants performed a spatial frequency discrimination task between stimuli of two types. The first type showed the described relationship between movement direction and temporal cues, the second stimulus type did not. We expected that when temporal cues can be optimized by moving in a certain direction, movements will be adjusted to this direction. However, movement adjustments were assumed to be based on sensory information, which accumulates over the exploration process. We analyzed 3 individual segments of the exploration process. As expected, participants only adjusted movement directions in the final exploration segment and only for the stimulus type, in which movement direction influenced temporal cues. We conclude that sensory signals on the texture orientation are used online during exploration in order to adjust subsequent movements. Once sufficient sensory evidence on the texture orientation was accumulated, movements were directed to optimize temporal cues.
053 An Adaptive Strategy for an Immersive Visuo-Haptic Attention Training Game Xiaoxiao Yang, Dangxiao Wang, Yuru Zhang Attention training using virtual environments is a promising way to treat mental disorders such as attention-deficit hyperactivity disorder (ADHD). Interactive haptic tasks combined with immersive visual display provide a potential solution for attention modulation and training. In this paper, we introduced a visuo-haptic game consisting of stimulus-response tasks using fingertip pressure control with immersive visual display using the Occulus Rift. Users were required to press a force sensor using either the index or middle finger from either hand. In each trial, users needed to maintain a constant force with an expected tolerance within an allowable response time. An adaptive strategy was proposed to tune the difficulty level of the task to match the force control skill of the user, which may produce an optimal success rate in each trial to maintain users’ interest and keep them motivated. Furthermore, a randomized algorithm was adopted to vary the target fingertip, target force magnitude and target tolerance between adjacent trials, which was designed to avoid the boring repetition and thus to keep the users’ curiosity on the task. Experimental results on six participants show that the proposed strategy was able to obtain different expected success rates, i.e. either 79.4% or 50%.
062 Deaf-blind Can Practise Horse Riding with the Help of Haptics matjaz ogrinc, ildar farkhatdinov, rich walker, Etienne Burdet This paper introduces the first haptic interface to help blind and deaf-blind people to practice horse riding as a sportive, recreational and therapeutic activity. As a form of animal assisted therapy, horse riding has been shown to benefit people with various medical conditions. Among other benefits, horse riding can improve self-esteem and a sensation of independence. However, in the case of deaf-blind individuals a therapist or an interpreter must be present at all times to communicate with the rider by touch. We developed a novel interface which enables deaf-blind people to ride a horse while the therapist is observing and remotely providing cues to the rider, which improves their independence. Initial tests of the concept with an autistic deaf-blind individual received very positive feedback from the rider, his family and therapist.
063 Perceptual Force on the Wrist under the Hanger Reflex and Vibration Takuto Nakamura, Narihiro Nishimura, Taku Hachisu, Michi Sato, Vibol Yem, Hiroyuki Kajimoto The hanger reflex is a phenomenon that accompanies illusory force sensa-tion and involuntary head rotation when the head is fastened with a wire hanger. This phenomenon is also observed on the wrist, and is expected to apply when using small and simple haptic feedback devices. However, is-sues of slow response and the requirement for large actuators still remain. Here, we discuss the discovery of a new phenomenon: the perceptual force from the hanger reflex is enhanced when a vibration is also presented. If we can control the strength of the perceptual force induced by vibration, a smaller, simpler, and higher response device might be achieved, because a vibrator can be controlled easily. This paper reports details of this phenome-non, and the effect of the frequency and amplitude of the vibration on the strength of the perceptual force. We observed that low frequency (50-100 Hz) vibrations efficiently enhanced the perceptual force, and that partici-pants perceived a stronger perceptual force if the vibration of a greater am-plitude was presented. These results suggest that the enhancement of the per-ceptual force is controllable and can be applied to construct a new type of wearable haptic device.
064 A Pocket-size Alphabet Display Device with Letter Trajectories Presented to Fingers Koji Tanaka, Keisuke Hasegawa, Yasutoshi Makino, Hiroyuki Shinoda We propose a pocket-size device that enables users with no prior long-time trainings to intuitively read text letters using only their haptic sense. The device forces the user’s fingertip to trace trajectories of lowercase roman alphabet characters. In displaying multistroke characters, vibrotactile stimuli are accordingly superposed on fingers so that users can distinguish writing strokes from transient movements of fingers between strokes. Our experiments showed that participants could recognize all alphabet characters. They were able to identify them with an accuracy rate of approximately 80% when presented at an average rate of 1.4 s/letter. We also showed that the accuracy rate varied slightly depending on holding orientation of the device, and that these identification performances could be obtained after only five-minute training. These results suggest that the access to symbolic information via hap- tic modalities, which were conventionally considered to be of limited use among people with early blindness, would turn into practical mobile applications for people with late blindness or even people with normal vision.
067 Haptic Rendering of Thin, Deformable Objects with Spatially Varying Stiffness Priyadarshini Kumari, Subhasis Chaudhuri In real world, we often come across with soft objects having spatially varying stiffness such as human palm or a wart on the skin. In this paper, we propose a novel approach to render thin, deformable objects having spatially varying stiffness (inhomogeneous material). We use the classical Kirchhoff thin plate theory to compute the deformation. In general, physics based rendering of an arbitrary 3D surface is complex and time consuming. Therefore, we approximate the 3D surface locally by a 2D plane using an area preserving mapping technique – Gall-Peters mapping. Once the deformation is computed by solving a fourth order partial differential equation, we project the points back onto the original object for proper haptic rendering. The method was validated through user experiments and was found to be realistic.
069 An Eight-legged Tactile Sensor to Estimate Coefficient of Static Friction: Improvements in Design and Evaluation Wei Chen, Han Wen, Heba Khamis, Stephen Redmond According to the laws of friction, in order to initiate a sliding motion between two objects, a tangential force larger than the maximum static friction force is required. This process is governed by a material constant called the coefficient of static friction. Therefore, it is of great utility for robots to know the coefficient of static friction between its gripper and the object being manipulated, especially when a stable and precise grip on an object is necessary. Furthermore, it is most useful if the robot can estimate the coefficient of static friction upon touching an object at the very beginning of a manipulation task, instead of having to further explore the object before it tries to move the object. Motivated by this issue, we have designed (and in this paper, further improved) a novel eight-legged tactile sensor to estimate the coefficient of static friction between a planar surface and the sensing components of the prototype sensor (which will also serve as the gripper). While the basic principle of the sensor is still unchanged, here we highlight some improvements to the sensor’s design and evaluation, including more robustly controlled frictional angles (vital for the accurate sensing) and the use of a programmable xyz-stage during evaluation. The coefficients of static friction between the sensor and nine different materials were estimated and compared to a measurement obtained via traditional methods as a reference. For all testing materials, the estimated ranges cover the corresponding reference values. Good conformance with the reference coefficients is also visually indicated from a least-square fitted line of the estimated coefficients, which has a gradient close to one and an r2 value greater than 0.9.
075 Tactile Vision Substitution with Tablet and Electro-Tactile Display Haruya Uematsu, Masaki Suzuki, Yonezo Kanno, Hiroyuki Kajimoto We have developed a device that converts visual information on tablet into tactile information on fingertip, by mounting optical sensors and tactile display on the fingertip. Our first prototype using a vibrator for each finger revealed that it was difficult to recognize the information of the display with a-vibrator-on-a-finger concept, mainly because of its low resolution. Our second prototype used electro-tactile stimulation for this resolution issue. Based on our preliminary experiment with mechanical pin matrix, we decided to use a single index finger. In the experiment with alphabet recognition task, we confirmed that it is possible to recognize a relatively complex shapes on tablet with the device. Furthermore, we observed that learning curve is quite steep, which implies potential of the device.
079 Augmentation of Thermal Sensation on Finger Pad using Stimuli for Finger Side Katsunari Sato This paper proposes a thermal display that can present a virtual thermal sensation to the finger pad using thermal stimuli on the finger side. The author developed the prototype device and evaluated the perceived strength of the thermal sensation on the finger pad after the pad makes contacts with an object. The results confirm that users perceive hot or cold sensation even if there are no thermal stimuli on the finger pad by presenting stimuli to the finger side. Furthermore, the proposed method successfully improves thermal sensation by applying the same thermal stimuli to the finger side as the sensation on the finger pad.
104 Modal superimposition for multi-fingers Variable Friction tactile Device Sofiane GHENNA, Christophe Giraud-Audine, Frédéric Giraud, Michel Amberg, Betty Semail In this study, we develop and implement a method for su- perimposing two vibration modes in order to produce different tactile stimuli on two fingers located in different positions. The tactile stim- ulation is based on the squeeze film effect which decreases the friction between a fingertip and a vibrating plate. Experimental test have been conducted on a 1D tactile device. They show that it is possible to continuously control the friction on two fingers moving independently. Then, we developed the design of a 2D device based on the same principle, which gives rise to the design of a two-fingers tactile display. Evaluations were conducted using a modal analysis with experimental validation.
POSTERS 2, Wednesday, July 6
030 Both Fingers and Head are Acceptable in Sensing Tactile Feedback of Gaze Gestures Jari Kangas, Jussi Rantala, Deepak Akkil, Poika Isokoski, Päivi Majaranta, Roope Raisamo Larger tablet computers are not always easy to use in handheld configurations. Gaze input and especially gaze gestures provide an alternative input technology in such situations. We investigated the task performance and user experience in gaze gesture use when haptic feedback was provided either to fingers touching the tablet or behind the ears through the eyeglass frame. The participant’s task was to look at a display and complete simple two-stroke gaze gestures consisting of either one, two, or three repetitions. The results showed that the participants found feedback on both body locations to be equally pleasant and preferred haptic feedback to no feedback. Also, the participants favored feedback that was spatially congruent with gaze movement.
031 A Reconfigurable Haptic Joystick based on Magneto-Rheological Elastomers – System Design and First Evaluation Christian Hatzfeld, Johannes Bilz, Tobias Fritzsche, Mario Kupnik Haptic interfaces with reconfigurable characteristics such as joysticks promise new possibilities for interaction design with increased intuitivity, new functional schemes, and enhanced overall safety. In this paper, we investigate the usage of magneto-rheological elastomers (MRE) as functional materials for a haptic joystick for steering and control applications. MREs provide a base elasticity with an electrically manipulable damping and storage modulus in a dimensionally stable, viscoelastic compound that is especially suited to form an elastic or damping element. We present a basic sequential simulation approach for elastic and magnetic properties to dimension MRE material for actuation use. A commercially available joystick is modified with a reconfigurable compliance based on the optimized MRE actuator. It is able to display varying reaction torques of 0.1 to 0.5Nm for exciting currents of 0 to 4A in a movement range of -20° to 20°. An identification experiment with 21 subjects and 5 different characteristics determines a possible information transfer of 0.828 bit with individual performances as high as 1.62 bit.  Based on these results, we conclude that MRE actuators are a promising option for reconfigurable haptic interfaces with technological advantages compared to other actuation concepts.
054 Brain responses to execution errors during 3D motion. Boris Yazmir, miriam reiner, Hillel Pratt, Miriam Zacksenhouse We investigated brain potentials recorded by electroencephalography (EEG) signals in response to unpredictable disturbances to the position of a continuously moving controlled object. Disturbances can arise as a result of wind, surface changes or errors of the control interface. Disturbances cause execution error defined by unintended motion. In our work, we used novel experimental continuous 3D setup integrated with haptic control for better ecological experiment validity. Our results show a disturbance-locked potential with an early negative peak followed by a positive peak. Peak-to-peak amplitude increased with the disturbance magnitude. sLORETA source estimation at the time of the negative and positive peaks re-vealed strong activity in the vicinity of Brodmann area (BA) 7, known to be involved in sensorimotor integration and in the neural computation of dynamic motor errors. These results demonstrate the presence of disturbance-related brain activity.  Results further suggest a feedback signal for error detection and correction in EEG-based Brain-Computer Interfaces (BCI).
065 Investigation of human subjective feelings for surface textures of slipping objects based on the analysis of contact conditions Tsuyoshi Arakawa, Akira Nakahara, Kiyotaka Yarimizu, Masato Takahashi, Michiko Ohkura, Toshio Tsuji, Yuichi Kurita Humans can manipulate an object with grasp force maintained slightly above the minimum required to prevent slipping. When humans grasp and lift an object, they use fast acting receptors in the skin that respond to local slips that occurs prior to the gross slip. The estimation of the coefficient of friction and the detection of the incipient slipping play a key role in the human grasp stability. However, it is not easy to strictly measure the coefficient of friction between the skin and the object’s surface during object manipulations because the shape and dryness of individual’s skin widely varies. To quantitatively and continuously evaluate the slip condition during a sliding motion, we have proposed ‘eccentricity’ in the contact area, which is determined based on the changes in the contact area before and after the sliding. In this paper, we employ the eccentricity-based slip condition measurement and evaluate the slip condition between a human’s skin and various surface textures. Then we compared the results with the affective evaluation experiments to evaluate the subjective feeling of the surface texture, and discuss the influence of the slip condition on the subjective feeling. The results reveal that the slip condition in the contact area at the beginning and that at the middle range during a sliding motion include completely different information to evaluate the subjective feeling of surface texture. The fact suggests that the eccentricity-based slip condition measurement is useful to evaluate human’s subjective feeling of surface texture of products.
071 Reconsideration of Ouija Board Motion in Terms of Haptics Illusions Takahiro Shitara, Yuriko Nakai, Haruya Uematsu, Vibol Yem, Hiroyuki Kajimoto, Satoshi Saga Bodily movements caused involuntarily, for example while using a Ouija board, are called ideomotor actions. Our goal is to clarify the conditions under which Ouija board motion occurs, comparing visual, force, and vibrotactile cues and us-ing a novel pseudo haptic technique. In this study, we used a fingertip-type tactile display to find the conditions of occurrence of ideomotor action with the Ouija board. Results showed that vibrotactile cues lead to the occurrence of Ouija board motion, and that visual cues reinforce the displacement of motion.
077 Method of Observing Finger Skin Displacement on a Textured Surface Using Index Matching Seitaro Kaneko, Hiroyuki Kajimoto Relationship between skin displacement and subjective sensation is indispensable for the design of tactile feeling display. Previous works on the observation of the skin displacement mainly used flat glass plate and a camera. However, the flat glass is not a representative tactile texture that we daily touch. We developed a system that can observe interaction between textured surface and finger skin by using technique known as index matching. The textured plate is immersed in the oil with the same refractive index, so that the texture became invisible. The finger skin is printed with markers, and its movement is analyzed by image processing. We also show a preliminary result of the observation when finger strokes on 0.5 mm interval grating.
082 Frequency-Specific Masking Effect by Vibrotactile Stimulation to the Forearm Yoshihiro Tanaka, Shota Matsuoka, Wouter Bergmann Tiest, Astrid Kappers, Kouta Minamizawa, Akihito Sano This paper demonstrates frequency-specific masking of tactile sensations on the index finger by remote vibrotactile stimulation. A vibration of 50 Hz was presented to the index finger. In three experimental conditions, the detection threshold for this vibration was determined with a masking vibration presented to the forearm of 50 Hz (the same frequency), of 200 Hz (a different frequency), or no masking vibration. The detection threshold for the 50 Hz stimulus on the fingertip increased significantly when a masking vibration of the same frequency was used, but not with a different frequency. This frequency-specific effect has applications in the modulation of tactile textures, for example in augmented reality.
083 The Roughness Display with Pen-like Tactile Device for Mobile Terminal peng deng, juan wu, xingjian zhong In this paper, a pen-like tactile device is designed to display texture roughness with vibration of piezoelectric actuator. The texture roughness is rendered by adjusting the amplitude and frequency of driving voltage for piezoelectric actuator. A perceptional-based haptic texture model is proposed for roughness display. In the model, the profile height of texture surface is extracted with image processing algorithm and set as the control parameter of vibrating intensity. The subjective factor like exploring speed is also considered in the model to slightly modulate the frequency of driving voltage. Two tactile perceptional experiments are conducted to evaluate the performance of the texture roughness display system. Experiment results show that the system can render realistic roughness with low cost and is suitable for mobile terminal.
087 ViSecure: A Haptic Gesture Authentication System Steven Strachan, Sabrina Panëels Secure authentication is an important part of our everyday interaction with computers. While the traditional password or pin-code still dominates this area, there has been a move towards more novel forms of authentication including gestures and biometric finger printing. In this paper we present the use of a wearable localized vibration device as a method for authentication that is both secure and discrete and which removes the need to memorize pin codes or passwords. An initial user study found that participants were open to this kind of device and interaction.
089 Accuracy Improvement of Torque Estimation between a Surgical Robot Instrument and Environment in Single-DOF Motion Suhwan Park, Cheongjun Kim, Doo Yong Lee Strain gauges attached to the driving pulleys of the instrument of surgical robots allow estimation of the torque between the instrument and environment. Friction in the torque transmission, however, deteriorates accuracy of the estimation. This paper proposes a method to reduce the estimation error using a friction model and Butterworth low-pass filter. The friction model is developed based on Dahl model and reflects the characteristics of the particular driving mechanism. Experimental results show that the relative error can be reduced to 3.49% in case of a sine wave motion.
093 Observing Touch from Video: The Influence of Social Cues on Pleasantness Perceptions Christian Willemse, Gijs Huisman, Merel Jung, Jan Van Erp, Dirk Heylen In order to advance the understanding of affective touch perceptions, and in particular to inform the design of physical human-robot interactions, an online video study was conducted in which observed stroking touches were assessed on perceived pleasantness. Touches were applied at different velocities and either with a human hand, a mannequin hand, a robot hand, or a plastic tube. In line with earlier research, it was found that stroking touches with a velocity of ca. 3 cm/s were rated as most pleasant. Moreover, the subjective pleasantness scores suggest that the stimulus type interacts with the stroking velocity. The possible roles that social agency, expectations, and anthropomorphism may play in perceptions of pleasantness are discussed.
097 Low-amplitude textures explored with the bare finger: roughness judgments follow an inverted U-shaped function of texture period modified by texture type Knut Drewing Roughness is probably the most salient dimension pertaining to the perception of textures by touch. It is established that roughness judgments for coarse textures are based on a spatial sensory code that is associated with spatial variability in skin deformation. But it is controversial whether a temporal sensory code is also used. Here, the sensory codes to roughness during bare finger exploration of coarse textures are studied by varying the shape of the textures’ elements and the exploration mode. Participants were presented with square-wave gratings that were defined along one dimension and sine-wave gratings that were defined along one or two dimensions. Textures of each type varied in their spatial half period between 0.25 and 5.17 mm. Participants explored the textures by a lateral movement or a stationary finger contact. Exploration mode did not affect judged roughness in ways indicating the use of a temporal code. Surprisingly, roughness followed an inverted U-shape function of the textures’ period. The exact function depended on the texture type. These effects are explained by the interplay of two components in the spatial code: variability in skin deformation due to the finger’s intrusion into the texture, which increases with the textures’ period up to a maximum, and variability associated with the spatial frequency of the deformation, which decreases with spatial period.
099 A linear optimization procedure for a EMG-driven NeuroMusculoSkeletal model parameters adjusting: validation through a myoelectric exoskeleton control Domenico Buongiorno, Francesco Barone, Massimiliano Solazzi, Vitoantonio Bevilacqua, Antonio Frisoli This paper presents a linear optimization procedure able to adapt a simplified EMG-driven NeuroMusculoSkeletal (NMS) model to the specific subject. The optimization procedure could be used to adjust a NMS model of a generic human articulation in order to predict the joint torque by using ElectroMyoGraphic (EMG) signals. The proposed approach was tested by modeling the human elbow joint with only two muscles. Using the cross-validation method, the adjusted elbow model has been validated in terms of both torque estimation performance and predictive ability. The experiments, conducted with healthy people, have shown both good performance and high robustness. Finally, the model was used to control directly and continuously a exoskeleton rehabilitation device through EMG signals. Data acquired during free movements prove the model ability to detect the human’s intention of movement.
100 Data-Driven Modeling of Anisotropic Haptic Textures: Data Segmentation and Interpolation Arsen Abdulali, Seokhee Jeon This paper presents a new data-driven approach for modeling haptic responses of textured surfaces with homogeneous anisotropic grain. The approach assumes unconstrained tool-surface interaction with a rigid tool for collecting data during modeling. The directionality of the texture is incorporated in modeling by including 2 dimentional velocity vector of user’s movement as an input for the data interpolation model. In order to handle increased dimentionality of the input, improved input-data-space-based segmentation algorithm is introduced, which ensures evenly distributed and correctly segmented samples for interpolation model building. In addition, new Radial Basis Function Network is employed as interpolation model, allowing more general and flexible data-driven modeling framework. The estimation accuracy of the approach is evaluated through cross-validation in spectral domain using 8 real surfaces with anisotropic texture.
102 Simulating Affective Touch: Using a Vibrotactile Array to Generate Pleasant Stroking Sensations Gijs Huisman, Aduén Darriba Frederiks, Dirk Heylen Gentle stroking touches are rated most pleasant when applied at a velocity of between 1-10 cm/s. Such touches are considered highly relevant in social interactions. Here, we investigate whether stroking sensations generated by a vibrotactile array can produce similar pleasantness responses, with the ultimate goal of using this type of haptic display in technology mediated social touch. A study was conducted in which participants received vibrotactile stroking stimuli of different velocities and intensities, applied to their lower arm. Results showed that the stimuli were perceived as continuous stroking sensations in a straight line. Furthermore, pleasantness ratings for low intensity vibrotactile stroking followed an inverted U-curve, similar to that found in research into actual stroking touches. The implications of these findings are discussed.
107 Design and Development of a Multimodal Vest for Virtual Immersion and Guidance Gonzalo Garcia Valle, Ferre Manuel, Jose Breñosa, Rafael Aracil, Jose María Sebastian, Christos Giachritsis This paper is focused in the development of a haptic vest to increase the immersion and realism in virtual environments, through delivering vibrotactile feedback. The first steps to achieve touch-based communication are presented in order to set an actuation method based on vibration motors. In this manner, vibrotactile patterns have to be validated for helping users to move inside virtual reality. The research analyzes human torso resolution and perception of vibration patterns, evaluating different kind of actuators and their location in the vest. Induced sensations depends on each specific pattern created as shown in the results of this study. The performed experiments help to perform sensations in comparison with the feeling in a real environment.
108 Reducing Visual Dependency with Surface Haptic Touchscreens Yu-Jen Lin, Sile O’Modhrain Interactions with current touchscreen is highly dependent on a pattern of visual feedback. Recently, researchers have developed surface haptic technology that provides haptic feedback on flat touchscreens, which presents an opportunity to add tactile responses to touchscreen interactions. Previous studies have found that haptic feedback in other interface can increase the speed and accuracy of task performance and create a more realistic experience. This paper demonstrates that surface haptic feedback can improve the speed and accuracy of manipulating non-visual bullseye menus giving users greater confidence while performing selection tasks. Results suggest that technology could be incorporated into applications on touchscreen devices where the user’s visual sensory channel is already occupied with other tasks, such as driving or running.
109 Tension Based Wearable Vibro Acoustic Device for Music Appreciation Yusuke Yamazaki, Hironori Mitake, Shoichi Hasegawa We propose a new vibro acoustic device that consists of a string and two motors. It names Wearable Tension based Vibro Acostic Device (WTV). To prove it has better performance than conventional wearable devices, which have vibrators in, we conducted two different experiments. First, we measured the amplitude of the vibration of the skin while using WTV and Haptuator. Compared with Haptuator, we found out that WTV is better at transmitting low frequency waves with a wider range throughout the body. Secondly, we examined the subjective evaluation of acoustic vibration using both devices. Almost all participants considered WTV was a better option to use as a vibro acoustic device. With this, we conclude that WTV can replace any conventional wearable vibro acoustic devices.
118 At-Home Computer-Aided Myoelectric Training System for Wrist Prosthesis Anastasios Vilouras, Hadi Heidari, William Taube Navaraj, Ravinder Dahiya Development of tools for rehabilitation and restoration of the movement after amputation can benefit from the teal time interactive virtual animation model of the human hand. Here, we report a computer-aided training/learning system for wrist disarticulated amputees, using the open source integrated development environment called “Processing”. The training system can be used for at-home learning to improve the functional effective calibration of prosthesis by the amputee. This work also presents the development of a low-cost surface Electro-MyoGraphic (sEMG) interface, which is an ideal tool for training and rehabilitation applications. The processed sEMG signals are decoded after digitization to control the animated hand. Experimental results demonstrate the effectiveness of the sEMG control system in acquiring sEMG signals for real-time control. The user also has the ability to connect their prosthetic limb with the training system and observe its operation for a more explicit demonstration of movements.
123 Textile Fabrics’ Texture: from Multi-Level Feature Extraction to Tactile Simulation Wael Ben Messaoud, Marie-Ange BUENO, Betty Semail In this study, the focus is put on the simulation of texture using a tactile feedback device based on ultrasonic vibrations. The textile fabrics are investigated as complex surfaces for simulation. The proposed multi-level feature extraction of the textile fabrics is based on the friction profile measured using a tribometer. Two types of sliders are used here: the first slider is an aluminum fine rigid tool to characterize the fine details of the surfaces while the second is a real finger operated to characterize the envelope of the signal. By that way, the input signals for the tactile stimulator perform the levels of characteristics. Finally, a psychophysical experiment is carried out to validate the capability to find a level of the texture amplitude which can simulate well the real fabrics textures.
141 Electrovibration Signal Design A Simulative Approach Zlatko Vidrih, Eric Vezzoli Electrovibration technique can modify user’s perception of a surface through the modulation of the sliding friction accordingly to the voltage applied. This paper is introducing a novel approach to virtual haptic rendering in electrovibration based haptic displays in order to pro- vide realistic feeling of a simulated surface. The required voltage signal is obtained using a simplified equation able to simulate tactile scenarios on real and virtual surfaces. The approach was validated by the use of a finite element computational framework. A database of precompiled tactile scenarios was generated to predict outputs for custom paramet- ric surfaces through a conditional average estimator method. In addition, an experimental database obtained by active exploration of different sur- faces, is utilised for texture rendering. A web application, comprising the algorithms described in the paper, has also been developed, and is freely available to use at
POSTERS 3, Thursday, July 7
073 Low-Frequency Vibration Actuator using a DC Motor Vibol Yem, Ryuta Okazaki, Hiroyuki Kajimoto In our previous study, we found that a normal DC motor can be used for vi-bro-tactile and pseudo-force presentation. In the present study, we developed a new vibration actuator using a DC motor that can generate much stronger vibrations than a normal DC motor and produce very low frequency of vi-brations. We proposed that the stator of the motor could be used as both the vibration mass and fixed rotor of the actuator. To evaluate this design con-cept, we developed a prototype actuator that can be driven in two modes: stator mode (i.e., the new design concept) and normal mode. The experiment results revealed that stronger vibrations can be obtained on a fingertip in sta-tor mode because the fixed part that comprises the rotor was lighter and the vibration mass using the stator was heavier. We also confirmed that the actu-ator can be driven at very low frequency (1 Hz) in stator mode.
088 Enabling wearable soft tactile displays with electroactive smart elastomers Gabriele Frediani, Hugh Boys, Stefan Poslad, Federico Carpi This paper presents ongoing developments in our lab to develop wearable soft tactile displays made of electroactive smart elastomers. The conceived devices are aimed at allowing for multiple-finger interaction with virtual soft bodies, via soft electrically-deformable interfaces. The overall system consists of soft tactile displays arranged at the user’s fingertips, which generate an electrically tuneable force according to information captured by an optical three dimensional finger tracking system, combined with a virtual environment that represents the position of the fingers. The tactile displays are based on an original design which uses the electromechanically active polymer transduction technology known as dielectric elastomer actuators. The paper presents our latest demonstrators, which allow users to probe a soft object with one finger, and describes ongoing development towards a multiple-finger system, based on a new compact design of the tactile displays.
110 Individual Differences in Skin Vibration and Contact Force during Active Touch Makiko Natsume, Yoshihiro Tanaka, Akihito Sano This paper investigates individual differences in exerted contact force on the basis of skin-propagated vibration that is elicited when rubbing an object. Contact force and skin vibration were measured when participants spontaneously rubbed eight different textures with their fingertip and subsequently, the same experiment was conducted with about half or twice the spontaneous force. The results showed that individual difference in the skin vibration was smaller than that in the spontaneous contact force. Furthermore, the results in different forces showed that intensity of the skin vibration was increased with increase of the contact force, but its coefficient of variance among different textures tended to be decreased with increase of the contact force. Thus, humans might spontaneously use a contact force in order to obtain the skin vibration having a somewhat strong intensity and great variation for textures.
128 An attempt to induce a strong rubber hand illusion under active-hand movement with tactile feedback and visuotactile stimulus Ken Itoh, Shogo Okamoto, Masayuki Hara, Yoji Yamada We combined a few methods to effectively create the illusion of embodiment and sense of body motion in the framework of the rubber hand illusion. In our experiments, active hand movements and self-stimulation were employed instead of classical passive tactile stimuli applied to still hands. The combination of these conditions effectively created the illusion. Furthermore, we collectively tested the effects of visual stimuli that were accompanied with tactile sensations. Specifically, we observed that when an object associated with tactile sensations was moving around the fake hand, the illusion tended to be more intensively induced than when an object that was unlikely to be associated with tactile sensations was placed still near the fake hand.
133 Psychophysical Optimization of Friction Modulation Tactile Interfaces Power Sednaoui Thomas, Eric Vezzoli, David Gueorguiev, Michel Amberg, Cedrick Chappaz, Betty Semail Ultrasonic vibration and electrovibration can modulate the friction between a sur-face and a sliding finger. The power consumption of these devices is critical to their integration in modern mobile devices such as smartphones. This paper pre-sents a simple control solution to reduce up to 68.8% this power consumption by taking advantage of the human perception limits.
134 End Effector for a Kinesthetic Haptic Device Capable of Displaying Variable Size and Stiffness Nathan Usevitch, Rohan Khanna, Robert Carrera, Allison Okamura A novel kinesthetic/tactile end effector capable of changing size and stiffness in a user’s hand is integrated with an existing three-degree-of-freedom kinesthetic haptic device. This system enables the creation of more immersive virtual environments that engage both kinesthetic senses through the existing haptic device and cutaneous senses through the end effector’s changes in stiffness and size. Size change is achieved by closed loop control of air pressure within a pneumatic cavity enclosed by a flexible membrane, and stiffness is varied by controlling vacuum level in an outer layer of particle jamming material.
136 Tactile Apparent Movement as a Modality for Lower Limb Haptic Feedback Daniel Chen, Junkai Xu, Peter Shull, Thor Besier Wearable haptic technology has been shown to be effective for motion training and rehabilitation. However, one challenge is providing multiple intuitive tactile feedback during walking and hence new feedback methods need to be explored. Experiments were conducted to explore the use of tactile apparent movement on the lower extremity and its feasibility as a feedback modality. Optimal stimulus duration and inter-stimulus onset interval (ISOI) combinations were determined. We obtained the optimal mean ISOIs at six different stimulus durations (from 100 – 200 ms) and then measured the subjects’ left and right perception accuracy and response times when those stimuli were presented in a randomized trial during standing and walking. Using the optimal stimulus duration yielding an accuracy of 97% and a response time < 1700 ms respectively. This study shows that apparent movement can be an effective feedback modality during walking, given an optimal stimulation response.
139 Toward Non-Visual Graphics Representations on Vibratory Touchscreens: Shape Exploration and Identification Jennifer Tennison, Jenna Gorlewicz Considerable advancements in vibratory and auditory feedback have transformed the touchscreen from a simple visual input/output device to one that is highly interactive and multimodal. While auditory feedback is useful in tasks where dictation is sufficient, it can be tedious and limited in tasks that require interpretation of graphics. In this work, we focus on exploration strategies, identification accuracy of graphics, and how repetition at smaller scales may help users identify similar graphics when only vibratory feedback is used on touchscreens. We conducted shape identification tasks with 56 blindfolded participants. Results suggest users are able to reliably identify basic 2D shapes within 90 seconds using only haptic feedback. Users were also able to identify smaller shapes with thin vibrating borders at rates comparable to their larger counterparts after being exposed to the larger shapes first. We also make observations on successful exploratory procedures employed and compare approaches among users. These findings serve to inform non-visual interface design using haptic feedback capabilities on touchscreens.
142 Studying one and two-finger perception for the discrimination of tactile directional cues Yoren Gaffary, Maud Marchal, Adrien Girard, Marine Pellan, Anouk Asselin, Benoit Peigne, Mathieu Emily, Anatole Lécuyer In this paper we study the perception of directional tactile cues by one or two fingers.We compare the use of the index, middle, or ring finger, as well as all the possible couples of fingers. We used a tactile device able to stretch the fingertip surface in $2$ DOF along four directions: horizontal, vertical, and the two diagonals. We measured the accuracy for discriminating the directions, as well as the subjective preference, depending on the (couple of) finger(s) stimulated. Our results show first that using index and/or middle finger performs significantly better than using the ring finger on both qualitative and quantitative measures. Then, the results when comparing one versus two-finger configurations are contrasted. The diagonals are better-discriminated using one finger than two. But using two fingers enables a better perception of the horizontal direction. These results pave the way to other studies on one versus two-finger perception, and raise methodological considerations for the design of multi-finger tactile devices.
143 Computational Assessment of Mechanical Triggers for Spiking Activity during Surface Exploration Teja Vodlak, Zlatko Vidrih, Primoz Sustaric, Tomaz Rodic, Johan Wessberg, Djordje Peric This article discusses recent progress towards understanding of human tactile perception by exploiting finite element analysis to simulate the experiments done in vivo, and statistical tools to correlate simulated output with microneurography recordings. Elucidation of the mechanisms that govern human tactile perception is essential for understanding of human touch, not only from psychophysical point of view in terms of affective touch, but also from mechanical: identification of potential trigger parameters responsible for mechano-transduction would have an important influence on virtual prototyping and texture encoding, and would therefore play a vital role in further development of haptic devices.
144 Impact of Combined Stimuli on the Perception of Transient Forces Connie Wu, Erica Chin, Michael Fanton, Allison Okamura This paper discusses the development and characterization of a system for replicating the sensation of object-hand impacts. We present a novel wearable haptic band, comprised of a C2 Tactor voice coil actuator and a servo-powered pressing mechanism.  A virtual reality simulation in which a user actively bounces a ball on their hand was synced with the vibrations from a C2 Tactor and pressure from a servo motor. User studies were conducted to determine the just-noticeable difference of pressure stimuli and realism of impact events with and without vibrations during the rendering of transient forces. We found that the presence of vibration reduced the just-noticeable difference of the device. Moreover, the addition of a constant vibration feedback to pressure appears to have more of an impact on the perception of the lower pressure levels than the higher pressure levels. These results outline important considerations for the design of future devices intended to render transient haptic forces.
147 HandsOn: enabling embodied, creative STEM e-learning with programming-free force feedback Gordon Minaker, Oliver Schneider, Richard Davis, Karon MacLean Embodied, physical interaction can improve learning by making abstractions concrete, while online courses and interactive lesson plans have increased education access and versatility. Haptic technology could integrate these benefits, but requires both low-cost hardware (recently enabled by low-cost DIY devices) and accessible software that enables students to creatively explore haptic environments without writing code. To investigate haptic e-learning without user programming, we developed HandsOn, a conceptual model for exploratory, embodied STEM education software; and implemented it with the SpringSim interface and a task battery for high school students. In two studies, we confirm that low-cost devices can render haptics adequately for this purpose, find qualitative impact of SpringSim on student strategies and curiosity, and identify directions for tool improvement and extension.
150 Mind the bump: effect of geometrical descriptors on the perception of curved surfaces with a novel tactile mouse Mariacarla Memeo, Luca Brayda In this work we present a new haptic assistive device, the TActile MOuse 3 (TAMO3), designed to support construction of mental maps in absence of vision. Since curvature is a sufficient information in recognition and classification of shapes [10] we evaluate TAMO3 in a curvature discrimination task: curves were rendered, on one finger only, through geometrical descriptors such as elevation and inclination, in three degrees of freedom. We assessed how performance and mental workload were influenced by such descriptors. Inclination cues confirm to be associated with higher precision and higher mental demand, with no increase in frustration. Therefore, as delivered by our device, inclination seems to be an effective haptic cue to mentally construct curved virtual shapes. The joint analysis of aspects from psychophysics and workload confirms to be essential when designing assistive haptic devices since it provides different and complementary results.
157 On Generation of Active Feedback with Electrostatic Attraction Ugur Alican Alma, Gholamreza Ilkhani, Evren Samur In this study, an active electrostatic tactile display, which is capable of applying directional force to finger, is analyzed. Directional forces are created using friction induced by electrostatic attraction. A shaker is used to move the tactile display with respect to the stationary finger. In order to investigate the factors affecting active feedback, a combination of signals is implemented. In the first step, minimum relative displacement necessary for directional force is examined. In the second step, lateral forces are measured for four distinct frequencies of electrostatic excitation. Finally in the third step, effect of amplitude of excitation voltage is investigated. The results show the feasibility of creating active feedback on an electrostatic tactile display. Minimum relative displacement is found as 4 mm. Increasing frequency and amplitude of electrostatic signal lead to higher value of the directional force.
158 A novel distal and proximal upper limb stroke rehabilitation system Michele Barsotti, Edoardo Sotgiu, Daniele Leonardis, Mine Sarac, Giada Sgherri, Giuseppe Lamola, Caterina Procopio, Carmelo Chisari, Antonio Frisoli This paper presents a novel neuro-rehabilitation system for recovery of the arm and hand motor functions involved in reaching and grasping. The system is based on robotic assistance of the hand closing and opening within specific exercises performed in virtual reality.  The developed virtual scenario and system interface allow full and easy parametrization, performed directly by clinicians. This allows adaptation of the exercises and of the robotic assistance to the needs of the patient, encouraging training of the hand with proper recruitment of the residual motor functions. Feasibility of the proposed rehabilitation system was evaluated through an experimental rehabilitation session, conducted by clinicians with 4 healthy participants and 2 stroke patients. All subjects were able to perform the proposed exercises with parameters adapted to their specific motor capabilities. Positive results regarding system usability and functionalities promoted its application to a prolonged clinical study with stroke patients, for evaluating effectiveness of the system in neuro-rehabilitation.
164 Calibration Method of Thermal-Radiation-Based Haptic Display Satoshi Saga When a human places his hands over a source of heat, his hands become worm owing to thermal radiation. In this research, we employ spatially controlled thermal radiation to display a virtual shape. At a temperature near the nociceptive temperature, a person will tend to avoid a heated region. Using this space, our proposed system displays virtual shape-like region. In this paper, we describe the proposed radiation system and calibration method, and evaluate displayed feeling of proposed method.
166 Milliseconds matter: Temporal order of visuo-tactile stimulation affects the ownership of a virtual hand Ioannis Dimitrios Zoulias, William Seymour Harwin, Yoshikatsu Hayashi, Slawomir Jaroslaw Nasuto The sense of body ownership, that one’s body belongs to oneself, is a result of the integration of different sensory streams. This sense however is not error-free; in 1998 Botvinick and Cohen showed the rubber hand illusion (RHI), an illusion that made a subject feel a rubber hand as their own. An important factor to induce the illusion is the timing of the applied visual and tactile stimulation to the rubber hand. Temporal delays greater than 500ms eliminate the illusory ownership. This study investigates previously unexplored small delays between stimulation modalities and their effect for the perception of the RHI. Through a virtual reality setup of the RHI paradigm, it is shown that small delays can significantly alter the strength of the illusion. The order of the sensory modality presented plays a catalytic role to whether or not the inter-modal delay will have an effect on the illusion’s strength.
171 Automatic Visualization and Graphical Editing of Virtual Modeling Networks for the Open-Source Synth-A-Modeler Compiler Edgar Berdahl, Peter Vasil, Andrew Pfalz Synth-A-Modeler (SaM) is an open-source environment for developing audio-haptic interactions.  It is based on the paradigm that a user develops a virtual model by interconnecting virtual objects and adjusting their parameters.  The SaM Designer has been created to help assist users in automatically visualizing virtual models and in graphically editing them.  Certain tasks, such as modifying the parameters for a group of objects, can be completed much faster in the Designer than by using a text editor.  The SaM Designer was able to automatically visualize 72 test models using an example set of visualization parameters.  With these tools, new virtual models such as a “waveguide drum” can be discovered, potentially facilitating the creation of novel audio-haptic interactions.
172 Acceptable Mismatch between Scaled 3D Image and Tactile Stimulation Ryota Arai, Yasutoshi Makino, Hiroyuki Shinoda This paper clarifies the acceptable scaling range of visual 3D image for a constant tactile stimulation.  Using a Fresnel lens and wideband vibrotactile device, we changed the magnification of 3D image while keeping the tactile feedback signal constant in collision events. The tested events were collisions between a rigid ob-ject in a subject hand and three kinds of balls hung as a pendulum. The results show that there is an acceptable range for each event and the range was compara-ble throughout the experiments. The results presented here provides the basic knowledge for practical 3D tactile-visual display in mid-air.