An Empirical Evaluation On Vibrotactile Feedback For Wristband System

With the rapid development of mobile computing, wearable wrist-worn is becoming more and more popular. But the current vibrotactile feedback patterns of most wrist-worn devices are too simple to enable effective interaction in nonvisual scenarios. In this paper, we propose the wristband system with four vibrating motors placed in different positions in the wristband, providing multiple vibration patterns to transmit multi-semantic information for users in eyes-free scenarios. However, we just applied five vibrotactile patterns in experiments (positional up and down, horizontal diagonal, clockwise circular, and total vibration) after contrastive analyzing nine patterns in a pilot experiment. The two experiments with the same 12 participants perform the same experimental process in lab and outdoors. According to the experimental results, users can effectively distinguish the five patterns both in lab and outside, with approximately 90% accuracy (except clockwise circular vibration of outside experiment), proving these five vibration patterns can be used to output multi-semantic information. The system can be applied to eyes-free interaction scenarios for wrist-worn devices.Comment: 10 pages

Vibration Propagation on the Skin of the Arm

Vibrotactile interfaces are an inexpensive and non-invasive way to provide performance feedback to body-machine interface users. Interfaces for the upper extremity have utilized a multi-channel approach using an array of vibration motors placed on the upper extremity. However, for successful perception of multi-channel vibrotactile feedback on the arm, we need to account for vibration propagation across the skin. If two stimuli are delivered within a small distance, mechanical propagation of vibration can lead to inaccurate perception of the distinct vibrotactile stimuli. This study sought to characterize vibration propagation across the hairy skin of the forearm. We characterized vibration propagation by measuring accelerations at various distances from a source vibration of variable intensities (100–240 Hz). Our results showed that acceleration from the source vibration was present at a distance of 4 cm at intensities \u3e150 Hz. At distances greater than 8 cm from the source, accelerations were reduced to values substantially below vibrotactile discrimination thresholds for all vibration intensities. We conclude that in future applications of vibrotactile interfaces, stimulation sites should be separated by a distance of at least 8 cm to avoid potential interference in vibration perception caused by propagating vibrations

Vibed: a prototyping tool for haptic game interfaces

Haptics in the form of vibrations in game interfaces have the potential to strengthen visual and audio components, and also improve accessibility for certain populations like people with deafblindness. However, building vibrotactile game interfaces is difficult and time consuming. Our research problem was how to make a prototyping tool that facilitated prototyping of vibrotactile game interfaces for phones and gamepads. The results include a description of the prototyping tool we built, which is called VibEd. It allows designers to draw vibrotactile patterns, referred to as vibes, that can easily be tested on phones and gamepads, and exported to code that can be used in game development. It is concluded, based on user tests, that a haptic game interface prototyping tool such as VibEd, can facilitate haptic game interface design and development, and by that contribute to game accessibility for persons with deafblindness

Design and Effect of Continuous Wearable Tactile Displays

Our sense of touch is one of our core senses and while not as information rich as sight and hearing, it tethers us to reality. Our skin is the largest sensory organ in our body and we rely on it so much that we don\u27t think about it most of the time. Tactile displays - with the exception of actuators for notifications on smartphones and smartwatches - are currently understudied and underused. Currently tactile cues are mostly used in smartphones and smartwatches to notify the user of an incoming call or text message. Specifically continuous displays - displays that do not just send one notification but stay active for an extended period of time and continuously communicate information - are rarely studied. This thesis aims at exploring the utilization of our vibration perception to create continuous tactile displays. Transmitting a continuous stream of tactile information to a user in a wearable format can help elevate tactile displays from being mostly used for notifications to becoming more like additional senses enabling us to perceive our environment in new ways. This work provides a serious step forward in design, effect and use of continuous tactile displays and their use in human-computer interaction. The main contributions include: Exploration of Continuous Wearable Tactile Interfaces This thesis explores continuous tactile displays in different contexts and with different types of tactile information systems. The use-cases were explored in various domains for tactile displays - Sports, Gaming and Business applications. The different types of continuous tactile displays feature one- or multidimensional tactile patterns, temporal patterns and discrete tactile patterns. Automatic Generation of Personalized Vibration Patterns In this thesis a novel approach of designing vibrotactile patterns without expert knowledge by leveraging evolutionary algorithms to create personalized vibration patterns - is described. This thesis presents the design of an evolutionary algorithm with a human centered design generating abstract vibration patterns. The evolutionary algorithm was tested in a user study which offered evidence that interactive generation of abstract vibration patterns is possible and generates diverse sets of vibration patterns that can be recognized with high accuracy. Passive Haptic Learning for Vibration Patterns Previous studies in passive haptic learning have shown surprisingly strong results for learning Morse Code. If these findings could be confirmed and generalized, it would mean that learning a new tactile alphabet could be made easier and learned in passing. Therefore this claim was investigated in this thesis and needed to be corrected and contextualized. A user study was conducted to study the effects of the interaction design and distraction tasks on the capability to learn stimulus-stimulus-associations with Passive Haptic Learning. This thesis presents evidence that Passive Haptic Learning of vibration patterns induces only a marginal learning effect and is not a feasible and efficient way to learn vibration patterns that include more than two vibrations. Influence of Reference Frames for Spatial Tactile Stimuli Designing wearable tactile stimuli that contain spatial information can be a challenge due to the natural body movement of the wearer. An important consideration therefore is what reference frame to use for spatial cues. This thesis investigated allocentric versus egocentric reference frames on the wrist and compared them for induced cognitive load, reaction time and accuracy in a user study. This thesis presents evidence that using an allocentric reference frame drastically lowers cognitive load and slightly lowers reaction time while keeping the same accuracy as an egocentric reference frame, making a strong case for the utilization of allocentric reference frames in tactile bracelets with several tactile actuators

Evaluating the effects of feedback type on older adults’ performance in mid-air pointing and target selection

“Hands-free” pointing techniques used in mid-air gesture interaction require precise motor control and dexterity. Although being applied in a growing number of interaction contexts over the past few years, this input method can be challenging for older users (60+ years old) who experience natural decline in pointing abilities due to natural ageing process. We report the findings of a target acquisition experiment in which older adults had to perform “pointand- select” gestures in mid-air. The experiment investigated the effect of 6 feedback conditions on pointing and selection performance of older users. Our findings suggest that the bimodal combination of Visual and Audio feedback lead to faster target selection times for older adults, but did not lead to making less errors. Furthermore, target location on screen was found to play a more important role in both selection time and accuracy of pointand- select tasks than feedback type

Exploring Hand-Based Haptic Interfaces for Mobile Interaction Design

Visual attention is crucial in mobile environments, not only for staying aware of dynamic situations, but also for safety reasons. However, current mobile interaction design forces the user to focus on the visual interface of the handheld device, thus limiting the user's ability to process visual information from their environment. In response to these issues, a common solution is to encode information with on-device vibrotactile feedback. However, the vibration is transitory and is often difficult to perceive when mobile. Another approach is to make visual interfaces even more dominant with smart glasses, which enable head-up interaction on their see-through interface. Yet, their input methods raise many concerns regarding social acceptability, preventing them from being widely adopted. There is a need to derive feasible interaction techniques for mobile use while maintaining the user's situational awareness, and this thesis argues that solutions could be derived through the exploration of hand-based haptic interfaces. The objective of this research is to provide multimodal interaction for users to better interact with information while maintaining proper attention to the environment in mobile scenarios. Three research areas were identified. The first is developing expressive haptic stimuli, in which the research investigates how static haptic stimuli could be derived. The second is designing mobile spatial interaction with the user's surroundings as content, which manifests situations in which visual attention to the environment is most needed. The last is interacting with the always-on visual interface on smart glasses, the seemingly ideal solution for mobile applications. The three areas extend along the axis of the demand of visual attention on the interface, from non-visual to always-on visual interfaces. Interactive prototypes were constructed and deployed in studies for each research area, including two shape-changing mechanisms feasible for augmenting mobile devices and a spatial-sensing haptic glove featuring mid-air hand-gestural interaction with haptic support. The findings across the three research areas highlight the immediate benefits of incorporating hand-based haptic interfaces into applications. First, shape-changing interfaces can provide static and continuous haptic stimuli for mobile communication. Secondly, enabling direct interaction with real-world landmarks through a haptic glove and leaving visual attention on the surroundings could result in a higher level of immersed experience. Lastly, the users of smart glasses can benefit from the unobtrusive hand-gestural interaction enabled by the isolated tracking technique of a haptic glove. Overall, this work calls for mobile interaction design to consider haptic stimuli beyond on-device vibration, and mobile hardware solutions beyond the handheld form factor. It also invites designers to consider how to confront the competition of cognitive resources among multiple tasks from an interaction design perspective.Visuaalisen huomiokyvyn säilyttäminen mobiililaitteita käytettäessä on tärkeää sekä ympäröivien tilanteiden havainnoimisen että käyttäjän turvallisuuden kannalta. Nykyiset mobiilikäyttöliittymäratkaisut kuitenkin vaativat käyttäjää keskittämään huomionsa mobiililaitteen ruudulle, mikä rajoittaa käyttäjän kykyä käsitellä ympäristöön liittyvää visuaalista informaatiota. Eräs paljon käytetty ratkaisu tähän ongelmaan on esittää informaatiota laitteen värinän avulla. Värinäpohjainen esitystapa on kuitenkin hetkeen sidottu ja siten ohimenevä, eikä sitä ole välttämättä helppo havaita käyttäjän liikkeellä ollessa. Toinen tapa hyödyntää ns. älylaseja visuaalisen informaation esittämiseen. Tämän tavan etuna on läpinäkyvä näyttöpinta, joka ei vaadi keskittämään katsetta erilliseen laitteeseen. Älylasien tyypilliset syötemuodot kuitenkin aiheuttavat ongelmia niiden sosiaaliselle hyväksyttävyydelle, mikä estää niiden laajempaa käyttöönottoa. Niinpä tämän tutkimuksen lähtökohtana on tarve uudenlaisten mobiilikäyttöliittymien suunnittelulle siten, että käyttäjän huomio säilyy ympäristössä. Väitöskirjatutkimuksessa esitetään, että ratkaisu voi pohjautua käsin kosketeltavaan haptiseen rajapintaan. Tutkimuksen tavoitteena on tuottaa mobiilitilanteisiin multimodaalisia käyttöliittymiä, joiden avulla käyttäjä voi vuorovaikuttaa informaation kanssa menettämättä huomiotaan ympäristöstä. Tutkimus keskittyy kolmeen tutkimuskohteeseen. Ensimmäisessä kehitetään ilmaisuvoimaisia haptisia ärsykkeitä tarkastelemalla staattisten haptisten ärsykkeiden suunnittelun mahdollisuuksia. Toinen kohde liittyy tilaan perustuvan vuorovaikutuksen suunnitteluun tilanteessa, jossa käyttäjä vuorovaikuttaa ympäristöön liittyvän informaation kanssa liikkeellä ollessaan, jolloin ympäristön visuaalinen havainnointi on tärkeää. Kolmannessa tutkimuskohteessa kehitetään uudenlainen syötemuoto älylaseille. Nämä kolme tutkimuskohdetta voidaan esittää osina jatkumoa, joka perustuu laitteen vaatiman visuaalisen huomion määrään täysin ei-visuaalisista täysin visuaalisiin käyttöliittymiin. Jokaisen tutkimuskohteen osalta kehitettiin vuorovaikutteisia prototyyppejä: kaksi muotoa muuttavaa mekanismia mobiililaitteiden täydentämiseksi uusilla palautemuodoilla sekä haptinen hansikas, joka mahdollistaa vuorovaikutuksen ilmassa suoritettavien eleiden ja haptisen palautteen avulla. Kaikkien kolmen tutkimuskohteen tulokset korostavat käsin kosketeltavien haptisten rajapintojen etuja käytännön sovelluksissa. Ensinnäkin muotoa muuttavat rajapinnat voivat tuottaa staattisia ja jatkuvia ärsykkeitä, joita voidaan hyödyntää mobiilivuorovaikutuksessa. Toiseksi haptisen hansikkaan mahdollistama suora vuorovaikutus ympäröivien maamerkkien kanssa auttaa säilyttämään visuaalisen huomion ympäristössä ja voi saada aikaan mukaansatempaavamman käyttökokemuksen. Kolmanneksi älylasien käyttäjät hyötyvät haptisen hansikkaan anturien mahdollistamasta huomaamattomasta elevuorovaikutuksesta. Tämä väitöskirja kehottaa mobiilikäyttöliittymien suunnittelijoita ottamaan huomioon muut kuin kädessä pideltävät laitemuodot sekä haptisten ärsykkeiden mahdollisuudet laajemmin kuin laitteen sisäänrakennetun värinäominaisuuden kautta. Väitöstutkimus myös pyytää suunnittelijoita ja muotoilijoita pohtimaan vuorovaikutussuunnittelun näkökulmasta, miten kohdata monisuorittamistilanteissa käyttäjän kognitiivisten resurssien välinen kilpailu