A Low Cost Tactor Suit for Vibrotactile Feedback

We constructed low cost tactors for vibrotactile feedback across the human arm for the purpose of providing a physical sensation surrogate for virtual objects. The tactors were built from readily available commercial parts, and provide low amplitude vibration for tactile feedback. The tactors are Velcro mounted on a custom suit designed to ensure localized sensations of each tactor. The suit is designed to be compatible with standard motion capture devices. Our suit provides 24 vibratory tactors in a tactor array on the user’s right arm and hand, and can easily be expanded to include the entire torso and body

DragTapVib: An On-Skin Electromagnetic Drag, Tap, and Vibration Actuator for Wearable Computing

The skin, as the largest organ distributed all over the human body, offers excellent opportunities for different kinds of input stimuli. However, most of the haptic devices can only render single sensations or they need to combine multiple complex components for generating multiple sensations. We present “DragTapVib” in this paper, a novel, ultra-low-cost, wearable actuator that can reliably provide dragging, tapping, and vibrating sensations to the user. Our actuator is fully electromagnetically-actuated with a moving tactor that can render three haptic feedbacks through systematically controlling the current inside the flexible PCBs. The actuator can be arranged with varying parts of the body which enriches the potentials to implement promising application scenarios including delivering the notification and providing immersive haptic feedback either in virtual reality or in gameplay. A prototypical technical evaluation demonstrated the mechanical properties of our actuator. We quantitatively conducted a series of psychophysical user studies (N= 12) to reveal the feasibility of our prototype. The overall absolute identification study for distinguishing three sensations accuracy at two body locations reached up to 97.2%

Wearable haptic systems for the fingertip and the hand: taxonomy, review and perspectives

In the last decade, we have witnessed a drastic change in the form factor of audio and vision technologies, from heavy and grounded machines to lightweight devices that naturally fit our bodies. However, only recently, haptic systems have started to be designed with wearability in mind. The wearability of haptic systems enables novel forms of communication, cooperation, and integration between humans and machines. Wearable haptic interfaces are capable of communicating with the human wearers during their interaction with the environment they share, in a natural and yet private way. This paper presents a taxonomy and review of wearable haptic systems for the fingertip and the hand, focusing on those systems directly addressing wearability challenges. The paper also discusses the main technological and design challenges for the development of wearable haptic interfaces, and it reports on the future perspectives of the field. Finally, the paper includes two tables summarizing the characteristics and features of the most representative wearable haptic systems for the fingertip and the hand

Somatic ABC's: A Theoretical Framework for Designing, Developing and Evaluating the Building Blocks of Touch-Based Information Delivery

abstract: Situations of sensory overload are steadily becoming more frequent as the ubiquity of technology approaches reality--particularly with the advent of socio-communicative smartphone applications, and pervasive, high speed wireless networks. Although the ease of accessing information has improved our communication effectiveness and efficiency, our visual and auditory modalities--those modalities that today's computerized devices and displays largely engage--have become overloaded, creating possibilities for distractions, delays and high cognitive load; which in turn can lead to a loss of situational awareness, increasing chances for life threatening situations such as texting while driving. Surprisingly, alternative modalities for information delivery have seen little exploration. Touch, in particular, is a promising candidate given that it is our largest sensory organ with impressive spatial and temporal acuity. Although some approaches have been proposed for touch-based information delivery, they are not without limitations including high learning curves, limited applicability and/or limited expression. This is largely due to the lack of a versatile, comprehensive design theory--specifically, a theory that addresses the design of touch-based building blocks for expandable, efficient, rich and robust touch languages that are easy to learn and use. Moreover, beyond design, there is a lack of implementation and evaluation theories for such languages. To overcome these limitations, a unified, theoretical framework, inspired by natural, spoken language, is proposed called Somatic ABC's for Articulating (designing), Building (developing) and Confirming (evaluating) touch-based languages. To evaluate the usefulness of Somatic ABC's, its design, implementation and evaluation theories were applied to create communication languages for two very unique application areas: audio described movies and motor learning. These applications were chosen as they presented opportunities for complementing communication by offloading information, typically conveyed visually and/or aurally, to the skin. For both studies, it was found that Somatic ABC's aided the design, development and evaluation of rich somatic languages with distinct and natural communication units.Dissertation/ThesisPh.D. Computer Science 201

Establishing a Framework for the development of Multimodal Virtual Reality Interfaces with Applicability in Education and Clinical Practice

The development of Virtual Reality (VR) and Augmented Reality (AR) content with multiple sources of both input and output has led to countless contributions in a great many number of fields, among which medicine and education. Nevertheless, the actual process of integrating the existing VR/AR media and subsequently setting it to purpose is yet a highly scattered and esoteric undertaking. Moreover, seldom do the architectures that derive from such ventures comprise haptic feedback in their implementation, which in turn deprives users from relying on one of the paramount aspects of human interaction, their sense of touch. Determined to circumvent these issues, the present dissertation proposes a centralized albeit modularized framework that thus enables the conception of multimodal VR/AR applications in a novel and straightforward manner. In order to accomplish this, the aforesaid framework makes use of a stereoscopic VR Head Mounted Display (HMD) from Oculus Rift©, a hand tracking controller from Leap Motion©, a custom-made VR mount that allows for the assemblage of the two preceding peripherals and a wearable device of our own design. The latter is a glove that encompasses two core modules in its innings, one that is able to convey haptic feedback to its wearer and another that deals with the non-intrusive acquisition, processing and registering of his/her Electrocardiogram (ECG), Electromyogram (EMG) and Electrodermal Activity (EDA). The software elements of the aforementioned features were all interfaced through Unity3D©, a powerful game engine whose popularity in academic and scientific endeavors is evermore increasing. Upon completion of our system, it was time to substantiate our initial claim with thoroughly developed experiences that would attest to its worth. With this premise in mind, we devised a comprehensive repository of interfaces, amid which three merit special consideration: Brain Connectivity Leap (BCL), Ode to Passive Haptic Learning (PHL) and a Surgical Simulator

Virtual Training via Vibrotactile Arrays

What is often missing from many virtual worlds and training simulations is a physical sense of the confinement and constraint of the virtual environment. We present a method for providing localized cutaneous vibratory feedback to the user’s right arm. We created a sleeve of tactors linked to a real-time human model; the tactors activate to apply sensation to the corresponding body area. The hypothesis is that vibrotactile feedback to body areas provides the wearer sufficient guidance to assume correct body configurations and ascertain the existence and physical realism of access paths. We present the results of human subject experiments that study both explicit and implicit training of skills using vibrotactile arrays. Implicitly, collision awareness is achieved by activating the appropriate tactor when a body part collides with the scene; thus, the user will attempt to correct his or her body configuration. Explicitly, we use the tactors to guide the body into the proper configuration. The results of human subject experiments clearly show that the use of full arm vibrotactile feedback improves performance over purely visual feedback for navigating the virtual environment, as well as allowing easy acquisition of new skills. These results validate the empirical performance of this concept

Doctor of Philosophy

dissertationWhen interacting with objects, humans utilize their sense of touch to provide information about the object and surroundings. However, in video games, virtual reality, and training exercises, humans do not always have information available through the sense of touch. Several types of haptic feedback devices have been created to provide touch information in these scenarios. This dissertation describes the use of tactile skin stretch feedback to provide cues that convey direction information to a user. The direction cues can be used to guide a user or provide information about the environment. The tactile skin stretch feedback devices described herein provide feedback directly to the hands, just as in many real life interactions involving the sense of touch. The devices utilize a moving tactor (actuated skin contact surface, also called a contactor) and surrounding material to give the user a sense of the relative motion. Several game controller prototypes with skin stretch feedback embedded into the device to interface with the fingers were constructed. Experiments were conducted to evaluate user performance in moving the joysticks to match the direction of the stimulus. These experiments investigated stimulus masking effects with both skin stretch feedback and vibrotactile feedback. A controller with feedback on the thumb joysticks was found to have higher user accuracy. Next, precision grip and power grip skin stretch feedback devices were created to investigate cues to convey motion in a three-dimensional space. Experiments were conducted to compare the two devices and to explore user accuracy in identifying different direction cue types. The precision grip device was found to be superior in communicating direction cues to users in four degrees of freedom. Finally, closed-loop control was implemented to guide users to a specific location and orientation within a three-dimensional space. Experiments were conducted to improve controller feedback which in turn improved user performance. Experiments were also conducted to investigate the feasibility of providing multiple cues in succession, in order to guide a user with multiple motions of the hand. It was found that users can successfully reach multiple target locations and orientations in succession

Master of Science

thesisHaptic interactions with smartphones are generally restricted to vibrotactile feedback that offers limited distinction between delivered tactile cues. The lateral movement of a small, high-friction contactor at the fingerpad can be used to induce skin stretch tangent to the skin's surface. This method has been demonstrated to reliably communicate four cardinal directions with 1 mm translations of the device's contactor, when finger motion is properly restrained. While earlier research has used a thimble to restrain the finger, this interface has been made portable by incorporating a simple conical hole as a finger restraint. An initial portable device design used RC hobby servos and the conical hole finger restraint, but the shape and size of this portable device wasn't compatible with smartphone form factors. This design also had significant compliance and backlash that must be compensated for with additional control schemes. In contrast, this thesis presents the design, fabrication, and testing of a low-profile skin-stretch display (LPSSD) with a novel actuation design for delivering complex tactile cues with minimal backlash or hysteresis of the skin contactor or "tactor." This flatter mechanism features embedded sensors for fingertip cursor control and selection. This device's nonlinear tactor motions are compensated for using table look-up and high-frequency open-loop control to create direction cues with 1.8 mm radial tactor displacements in 16 directions (distributed evenly every 22.5°) before returning to center. Two LPSSDs are incorporated into a smartphone peripheral and used in single-handed and bimanual tests to identify 16 directions. Users also participated in "relative" identification tests where they were first provided a reference direction cue in the forward/north direction followed by the cue direction that they were to identify. Tests were performed with the user's thumbs oriented in the forward direction and with thumbs angled inward slightly, similar to the angledthumb orientation console game controllers. Users are found to have increased performance with an angled-thumb orientation. They performed similarly when stimuli were delivered to their right or left thumbs, and had significantly better performance judging direction cues with both thumbs simultaneously. Participants also performed slightly better in identifying the relative direction cues than the absolute

A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses

A sense of touch is essential for amputees to reintegrate into their social and work life. The design of the next generation of the prostheses will have the ability to effectively convey the tactile information between the amputee and the artificial limbs. This work reviews non-invasive haptic feedback stimulation techniques to convey the tactile information from the prosthetic hand to the amputee’s brain. Various types of actuators that been used to stimulate the patient’s residual limb for different types of artificial prostheses in previous studies have been reviewed in terms of functionality, effectiveness, wearability and comfort. The non-invasive hybrid feedback stimulation system was found to be better in terms of the stimulus identification rate of the haptic prostheses’ users. It can be conclude that integrating hybrid haptic feedback stimulation system with the upper limb prostheses leads to improving its acceptance among users