– Tuesday sessions, July 5

Programme at a glance is here.

8:00 – registration desk opens (Queen’s Tower rooms)

9:00-10:00 – Keynote 1: Stephen Brewster, University of Glasgow, (Great Hall)

10:00-11:00 – Oral session 1: Perception of hardness and softness

033 10:00 – 10:15

What is the Hardness Perceived by Tapping?
Kosuke Higashi, Shogo Okamoto, Yoji Yamada Human can perceive the hardness of an object by tapping its surface. We compared the ranked subjective hardness and physical properties, including stiffness, viscosity, density, and Shore hardness of objects, and the frequencies and time constants of natural vibrations caused by tapping. As a result, the stiffness, frequency, and viscosity exhibited relatively strong positive correlation with perceived hardness. The results show that the viscosity influences hardness perception by tapping as well as the stiffness, whereas the stiffness or elasticity are considered to be major factors for hardness perception by pinching or pushing.
094 10:15 – 10:30

Haptics-1: Preliminary results from the first Stiffness JND identification experiment in space
André Schiele, Manuel Aiple, Thomas Krueger, Frank van der Hulst, Stefan Kimmer, Jan Smisek, Emiel den Exter On July 28th 2014, 23:47 UTC, the European Space Agency launched the Haptics-1 Kit to the International Space Station (ISS) on its last Automated Transfer Vehicle ATV-5. The Kit reached the station two weeks later, marking the first haptic master device to enter the ISS. The first force-feedback and human perceptual motor performance tests started to take place on December 30th 2014, and are the first of their kind in the history of spaceflight.Three astronauts participated in the Haptics-1 experiment until November 2015, allowing the investigation of the effects of microgravity on various psycho-motor performance metrics related with the usage of haptic feedback. Experiments are conducted following full adaptation to the space environment (after 3 months in space).This paper introduces the Haptics-1 experiment and associated hardware. Detailed experimental results are reported from a first stiffness just noticeable difference (JND) experimental study in space, carried out on the ISS and pre-flight on ground with 3 astronauts. The first findings from the experiment show no major alterations in-flight, when compared to on-ground data, if the manipulandum is secured in flight against a sufficiently stiff reference structure.
116 10:30 – 10:45

Haptic aftereffect of softness
Anna Metzger, Knut Drewing Past sensory experience can influence present perception. We studied the effect of adaptation in haptic softness perception. Participants compared two silicon rubber stimuli, a reference and a comparison stimulus, by indenting them simultaneously with the index fingers of their two hands and decided which one felt softer. In adaptation conditions the index finger that explored the reference stimulus had previously been adapted to another rubber stimulus. The adaptation stimulus was indented 5 times with a force of >15N, thus the two index fingers had a different sensory past. In baseline conditions there was no previous adaptation. We measured the Points of Subjective Equality (PSEs) of one reference stimulus to a set of comparison stimuli. We used four different adaptation stimuli, one was harder, two were softer and one had approximately the same compliance as compared to the reference stimulus. PSEs shifted as a function of the compliance of the adaptation stimulus: the reference was perceived to be softer when the finger had been adapted to a harder stimulus and it was perceived to be harder after adaptation to a softer stimulus. We conclude that recent sensory experience causes a shift of haptically perceived softness away from the softness of the adaptation stimulus. The finding that perceived softness is susceptible to adaptation suggests that there might be neural channels tuned to different softness values and softness is an independent primary perceptual quality.
135 10:45 – 11:00

Fingertip Recovery Time Depending on Viscoelasticity
Maria Laura D’Angelo, Darwin Caldwell, Ferdinando Cannella The aim of this paper is to investigate the recovery time of human fingertip mechanical properties after indentations cycles. To determine the influencing parameters, three indentation velocities, five recovery times and three subjects were tested. During each experiment, the participant fingertip was driven against a flat surface, while indentation displacement and velocity were controlled. The results show not only the indentation forces values increase depending on the indentation velocity increment, but also they decrease depending on the number of cycles. While the fingertip recovery depends on the time, but not on the indentation velocity. Finally the recovery time was determined: in 5 minutes the fingertip restored 99.6% of the initial mechanical properties.

11:00-11:20: coffee/tea break (Queen’s tower rooms)

11:20-11:40 – Teaser session 1 (Great Hall)

11:40-13:00 – Oral session 2: Haptic devices

040 11:40-11:55

Rendering Moving Tactile Stroke on the Palm Using a Sparse 2D Array
Jaeyoung Park, Jaeha Kim, Yonghwan Oh, Hong Tan The present study presents a new rendering algorithm for a moving tactile stroke on the palm of the hand placed on a sparse 2D array. Our algorithm utilizes the relation between signal duration and signal onset asynchrony previously proposed for “tactile brush” (Israr & Poupyrev, 2011), but extends it by applying 3-actuator phantom sensations and adjusting the sampling rate. We compared our proposed algorithm to the tactile brush algorithm for their similarity to the target trajectories and the uniformity of tactile stroke motions. The results show that the participants judged the tactile strokes with our algorithm to move significantly closer to target motions and with more uniform velocity than the “tactile brush.” The effect of our algorithm was more significant for the experimental stimuli with longer travel time and length.
068 11:55-12:10

High Spatial Resolution Midair Tactile Display  Using 70 kHz Ultrasound


Mitsuru Ito, Daisuke Wakuda, Seki Inoue, Yasutoshi Makino, Hiroyuki Shinoda We fabricated a midair tactile display using a 70 kHz airborne ultrasound. The spatial resolution of the display was improved 1.7 times compared with the conventional 40 kHz ultrasound tactile display. Since the focal spot diameter was smaller than a finger pad, the user could perceive a localized spot on the finger pad. In the experiment determining the physical properties, we found that the ultrasound attenuation at 70 kHz was comparable to that at 40 kHz. The small focal spot was successfully created as expected using the theory. The psycho-physical experimental results showed that the minimum perceivable radiation force for the focal spot at 70 kHz was smaller than that for the 40 kHz case and the smaller focal spot was easier to perceive. We also conducted a comparison test of the perceived force area with real contacts.
095 12:10-12:25

Mid-Air Ultrasonic Pressure Control on Skin by Adaptive Focusing
Seki Inoue, Yasutoshi Makino, Hiroyuki Shinoda Mid-air ultrasound can remotely invoke tactile sensation to bare hand. However, it is difficult to control it precisely because the hand itself scatters ultrasound. In this paper, a scattering model, which can be solved in real-time, is proposed and, this model can create a stronger focal point as compared to the conventional model. The proposed algorithm is based on the boundary element method and is a natural extension of the previously proposed phased array synthesis algorithms. Numerical analysis shows the relationship between the error of the surface model, computation time, and focusing performance. Psychophysical experiment shows that the internal tactile intensity of the focused ultrasound is significantly improved using the proposed adaptive focusing method. The proposed method can be used for mid-air ultrasound as a test bench of precise weak force haptic interaction.
084 12:25-12:40

Characterization of Ultrasound Tactile Display
Mohamad Eid, Georgios Korres Traditional haptic interfaces require physical contact between the haptic device and the user. Recently, an elegant solution is to provide contact-less tactile stimulation via airborne acoustic radiation pressure. However the characteristics of contactless tactile displays are not well studied in the literature. In this paper, we study the characteristics of ultrasonic tactile display as a haptic interface. In particular, we examine the effects of increasing the number of ultrasound transducers on four characteristics, namely the maximum producible force, the workspace, the workspace resolution, and the stimulation robustness. Three rectangular-shaped 2D array configurations are considered: single-tile (10×10 transducers), two-tiles (10×20 transducers), and four-tiles (20×20 transducers). Results show that the maximum producible force remains almost constant as the number of tiles increases whereas the elevation at which these maxima are generated increases. The workspace increases along the xy-plane as the number of tiles increase almost linearly, however, the elevation of the workspace remains almost the same. Finally, we found that the robustness of tactile display decreases as the number of tiles increases.
125 12:40-12:55

Pneumatic feedback for wearable lower limb exoskeletons further explored
Heidi Witteveen, Francisco Guerra, Victor Sluiter, Herman van der Kooij To improve control of wearable lower limb exoskeletons the sensory information flow should also be (partly) restored, especially when the users are Spinal Cord Injury subjects. Several methods, like electrotactile or electromechanical vibrotactile stimulation, to provide artificial sensory feedback have been studied thoroughly and showed promising results. Pneumatic tactile stimulation might be an alternative to these methods, because the stimulation amplitudes can be larger and in cases of force feedback, the modality of stimulation and sensing can be matched. In this study we have developed a setup that can provide pneumatic feedback with four feedback levels via three stimulation modalities: (1) amplitude modulation, (2) position modulation and (3) frequency modulation. The differences in subject stimulus perception between these three stimulation modalities were evaluated through a magnitude estimation task performed with 10 healthy subjects. Percentages correctly identified feedback levels were significantly higher for frequency modulation than the other two stimulation modalities. Also through questionnaires the subjects indicated that feedback through frequency modulation was the most intuitive and the only method where addition of an extra feedback level was indicated as possible. The results of this study show that pneumatic feedback is feasible, can provide high percentages of feedback level discrimination that are at least comparable to vibrotactile stimulation and therefore encourages further research to optimize the pneumatic setup.

13:00-13:45 – Lunch break (Queen’s tower rooms)

13:45-16:15 – Posters/demonstrations/expo (Queen’s tower rooms)

POSTERS 1 (Tue, Jul 4, 13:45-16:15, Queen’s Tower rooms)
005 A Study on Control of a Phantom Sensation by Visual Stimuli Arinobu Niijima, Takefumi Ogawa
006 Integrating Measured Force Feedback in Passive Multilateral Teleoperation Michael Panzirsch, Thomas Hulin, Jordi Artigas-Esclusa, Christian Ott, Ferre Manuel
007 Enhancement of Virtual Simulator for Maritime Crane Operations via Haptic Device with Force Feedback Yingguang Chu, Houxiang Zhang, Wei Wang
009 A Novel Haptic Stylus for Mobile Terminal Lei Tian, Aiguo Song, Dapeng Chen
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
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
026 Illusion of wet sensation by controlling temperature and softness of dry cloth Mai Sibahara, Katsunari Sato
027 How attention is allocated when using haptic touch: Shape feature distinction and discrimination strategy Toro Graven
036 It’s all about the Subject – Options to Improve Psychometric Procedure Performance Christian Hatzfeld, Viet Quoc Hoang, Mario Kupnik
038 Does haptics improve learning and recall of spatial information? A study using a virtual reality Nasendoscopy Simulation Greg Ruthenbeck, Michael Tlauka, Andria Tan
041 Perceived intensity of vibrotactile stimuli : Does your clothes really matter? Valérie Duthoit, Jean-Marc Sieffermann, Eric Enrègle, David Blumenthal
046 Affordable Wideband Sensor Coupled Vibrotactile Actuator Systems for Psychophysical Experiments Abhijit Biswas, Manivannan Muniyandi, Srinivasan Mandayam A.
050 Going against the grain – Texture orientation affects direction of exploratory movement Alexandra Lezkan, Knut Drewing
053 An Adaptive Strategy for an Immersive Visuo-Haptic Attention Training Game Xiaoxiao Yang, Dangxiao Wang, Yuru Zhang
062 Deaf-blind Can Practise Horse Riding with the Help of Haptics matjaz ogrinc, ildar farkhatdinov, rich walker, Etienne Burdet
063 Perceptual Force on the Wrist under the Hanger Reflex and Vibration Takuto Nakamura, Narihiro Nishimura, Taku Hachisu, Michi Sato, Vibol Yem, Hiroyuki Kajimoto
064 A Pocket-size Alphabet Display Device with Letter Trajectories Presented to Fingers Koji Tanaka, Keisuke Hasegawa, Yasutoshi Makino, Hiroyuki Shinoda
067 Haptic Rendering of Thin, Deformable Objects with Spatially Varying Stiffness Priyadarshini Kumari, Subhasis Chaudhuri
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
075 Tactile Vision Substitution with Tablet and Electro-Tactile Display Haruya Uematsu, Masaki Suzuki, Yonezo Kanno, Hiroyuki Kajimoto
079 Augmentation of Thermal Sensation on Finger Pad using Stimuli for Finger Side Katsunari Sato
104 Modal superimposition for multi-fingers Variable Friction tactile Device Sofiane GHENNA, Christophe Giraud-Audine, Frédéric Giraud, Michel Amberg, Betty Semail
DEMONSTRATIONS 1 (Tue, Jul 5, 13:45-16:15, Queen’s Tower rooms)
001 The Haptic Bracelets: Gait rehabilitation after Stroke Theodoros Georgiou, Simon Holland, Janet van der Linden
005 Enabling wearable soft tactile displays with electroactive smart elastomers Gabriele Frediani, Hugh Boys, Stefan Poslad, Federico Carpi
007 Reconsideration of Ouija Board Motion in Terms of Haptics Illusions Takahiro Shitara, Yuriko Nakai, Haruya Uematsu, Vibol Yem, Hiroyuki Kajimoto, Satoshi Saga
008 Tactile Vision Substitution with Tablet and Electro-Tactile Display Haruya Uematsu, Masaki Suzuki, Yonezo Kanno, Hiroyuki Kajimoto
010 Integrated Wireless and Wearable Haptic System for Virtual Interaction Andualem Tadesse Maereg ,David Reid, Atulya Nagar, Emanuele Lindo Secco
020 Haptics-based Simulation for Training and Learning Digital Rectal Examinations Alejandro Granados, Arthur Loisillier, Alastair Barrow, Naomi Low-Beer, Jenny Higham, Roger Kneebone, Fernando Bello
021 CuddleBits: an iterative prototyping platform for complex haptic display Paul Bucci, Xi Laura Cang, Matthew Chun, David Marino, Oliver Schneider, Hasti Seifi, Karon MacLean
033 Virtual Walking Generator by Rhythmical Modulation of Omnidirectional Images and Foot Sensations Takeo Hamada, Katsuya Yoshiho, Ryota Kondo, Yasushi Ikei, Koichi Hirota, Michiteru Kitazaki
037 HapticAid: Wearable Haptic Augmentation System based on Skin Vibration sensing Tomosuke Maeda, Roshan Peiris, Masashi Nakatani, Yoshihiro Tanaka, Kouta Minamizawa
042 Ungrounded 6-dof force display by asymmetric vibration: ‘Buru-Navi4 CubicForce 6D’ Hiroaki Gomi, Sho Ito, Tomohiro Amemiya, Shinya Takamuku
046 Social Touch in Human-Robot Interaction Merel Jung, Christian Willemse, Gijs Huisman, Jan Van Erp
051 High Spatial Resolution Midair Tactile Display  Using 70 kHz Ultrasound Mitsuru Ito, Seki Inoue, Daisuke Wakuda, Yasutoshi Makino, Hiroyuki Shinoda
053 FingerPressRig Ferdinando Cannella, Maria Laura D’Angelo
103 Do Not Guess It, Just Feel It: Experiencing Vibrotactile Guidance on a Head-mounted Display Victor Adriel Oliveira, Luciana Nedel, Anderson Maciel, Luca Brayda
106 Toward Open-Source Portable Haptic Displays: An Interactive Flight Simulation Demo with the Haplet3D Colin Gallacher, Arash Mohtat, Jozsef Kovecses
062 Tension Based Wearable Vibro Acoustic Device Yusuke Yamazaki, Hironori Mitake, Shoichi Hasegawa

16:15- 17:45 – Oral session 3: Haptics and motor control (Great Hall)

3 16:15-16:30

A versatile robotic haptic stimulator to study the influence of pain on human motor control and learning
Maxime Jeanneret, Carlo Bagnato, Alessandro Allievi, Etienne Burdet This paper presents an inexpensive, versatile and easy-to-install robotic tactile stimulator, capable of delivering computer-controlled innocuous and noxious mechanical stimuli. The system can be coupled with robotic interfaces typically employed to investigate human motor control and learning, and synchronized with the acquisition of relevant physiological measures. The design is based on a modified commercial rotative servomotor that actuates a 1-DOF parallel guiding mechanism connected to an end-effector that applies forces against a subject’s target body area. The position of the end-effector and the interaction force with the skin, as well as sensor readings of the subject’s movements, can be used by a microcontroller to control the stimulator. The results of experiments to test the stimulator’s control and subjects’ psychophysical responses show that the device provides robust and consistent mechanical stimulation, which elicits perceptual ratings compatible with previous relevant psychophysical studies. The presented system is the first to allow investigating the effects of painful versus innocuous stimulation on human motor control and learning.
043 16:30-16:45

Weight and Weightlessness Effects on Sensorimotor Performance during Manual Tracking
Bernhard Weber, Simon Schätzle, Cornelia Riecke, Brunner Bernhard, Sergey Tarassenko, Jordi Artigas-Esclusa, Ribin Balachandran, Alin Albu-Schäffer The effects of extra arm weight and weightlessness on sensorimotor performance were investigated in three empirical studies. In all studies, subjects performed two-dimensional tracking tasks with a joystick. Results indicated that extra arm weight did not decrease tracking performance, but decreased acceleration variance. In weightlessness, tracking performance decreased and the control of movement impulses was deteriorated. This result pattern was found during water immersion as well as during spaceflight. The sensorimotor performance losses in weightlessness could be compensated by providing additional haptic cues with the input device.
101 16:45-17:00

Individuals with Chronic Hemiparetic Stroke Correctly Match Forearm Position Within a Single Arm: Preliminary Findings
Erik Euving, Netta Gurari, Justin M. Drogos, Stuart Traxel, Arno H.A. Stienen, Julius P.A. Dewald Based on bimanual position matching assessments, more than half of individuals with hemiparetic stroke may have moderate to severe proprioceptive deficits. This study is the first of a series of studies designed to investigate the reason for the observed bimanual position matching deficits. In this work, we quantified the ability of five participants with chronic hemiparetic stroke (participants with stroke) and five age-matched participants without neurological impairments (controls) to match forearm positions within a single arm. According to the revised Nottingham Sensory Assessment, the participants with stroke all had impaired forearm position sense and unimpaired forearm movement direction sense, while the controls had unimpaired forearm position and movement direction sense. A custom robotic device was used to quantify each participant’s task performance during active movements when performing a single-arm memory matching task. Participants were asked to match the location of the forearm with a remembered target location. Results show that the participants with stroke identified the target location just as well as the controls. Based on our findings, we suggest that our participants with chronic hemiparetic stroke, who have deficits in matching forearm positions across both arms, have unimpaired forearm position sense within a single arm, and we suggest that the position matching deficits may arise for non-sensory related reasons. Future work will continue to use such behavioral studies to investigate possible central neural mechanisms that may be contributing to the observed bimanual position matching deficits.
112 17:00-17:15

Shape Features of the Search Target Modulate Hand Velocity, Posture and Pressure during Haptic Search in a 3D Display
Kathrin Krieger, Alexandra Moringen, Robert Haschke, Helge Ritter  We have investigated spontaneous haptic search in a scenario in which both the search target and the search field are represented by an unstructured composition of different primitive shapes.  In our experiment,blindfolded sighted individuals were asked, firstly, to learn a previously unknown complex target object and, secondly, to find this target object embedded in a complex shape landscape.  Our goal was to examine, how different shape characteristics of the complex search target influenced the overall search behaviour. We have evaluated data of eight participants by correlating the features, representing the search behaviour, with the features, representing the target object. This approach showed that the number of edges, number of vertices, mean height, volume, curved area and mean curvature have a global impact on the hand posture, velocity and pressure during the haptic search.
120 17:15-17:30

Haptic SLAM: an ideal observer model for Bayesian inference of object shape and hand pose from contact dynamics
Feryal M.P. Behbahani, Guillem Singla Buxarrais, Aldo Faisal We present a normative computational model for haptic exploration and shape reconstruction. This ideal observer model infers from contact point information on the surface of the hand and noisy hand proprioception, simultaneously the shape of a tactile explored object and estimates the true hand pose.The theory is  derived from robot visions approach to simultaneous localisation and mapping (SLAM) that we apply to haptic perception. Our method solely relies on the knowledge of object contacts on the end-points, noisy sensory information and motor control signals. We implement this normative theory using a recursive Bayesian estimate algorithm that can operate on experimental data from human subjects as well as from computer-based physical simulations (or a combination thereof).  We present a proof-of-principle reconstruction of object shape from multi-finger tactile exploration with contact points reconstructed using a physics engine. Our model provides a framework for principled study of natural human haptic exploration and context-aware prosthetics.
127 17:30-17:45

The Influence of Motor Task on Tactile Supression During Action
Nienke B. Debats, Marieke Rohde, Catharina Glowania, Anna Oppenborn, Marc O. Ernst Movement of a limb substantially decreases the intensity and sensitivity with which tactile stimuli on that limb are perceived. This movement-related tactile suppression likely interferes with performance in motor tasks that require the precise evaluation of tactile feedback, such as the adjustment of grip forces during grasping. Therefore, we hypothesize that suppression might be stronger for stimuli that are irrelevant to successful performance in a given motor task. To test this hypothesis, we measured participants’ perception of tactile intensity while performing different motor tasks. We investigated perception of both supra-threshold stimuli (Exp. 1: intensity discrimination) and stimuli close to the detection threshold (Exp. 2: detection). We compared tactile perception between two grasping conditions (active, tactile inputs irrelevant), a condition where participants pointed in the air (active, tactile inputs irrelevant) and a static condition (baseline). In both experiments, we observed tactile suppression in all three movement conditions but not the predicted attenuation of tactile suppression in the grasp conditions. Contrary to our hypothesis, there was even an amplification of tactile suppression in the grasping conditions of Exp. 1, which might be related to the movement velocity. In conclusion, we did not find evidence that motor tasks modulate the strength of tactile suppression. Our results further suggest that it is important to control for possible confounding variables, such as movement velocity and laterality, in this line of research.

17:45-18:00 – Teaser session for Work-in-Progress (Great Hall)

18:00-20:00 – Work-in-Progress poster session (Queen’s Tower rooms)

Go to Wednesday sessions