Soft Pneumatic Haptic Wearable to Create the Illusion of Human Touch.

The ability to deliver sensations of human-like touch within virtual reality remains an important challenge to immersive, realistic experiences. Since conventional haptic actuators impart distinctively unnatural effects, we instead tackle this challenge through the design of a rendering mechanism using soft pneumatic actuators (SPA), embedded within a wearable jacket. The resulting system is then evaluated for its ability to mimic realistic touch gesture sensations of grab, touch, tap, and tickle as performed by human fingertips. The results of our experiments indicate that the stimuli produced by our design were reasonably effective in presenting realistic human-generated sensations.

Deploying wearable sensors for pandemic mitigation: A counterfactual modelling study of Canada's second COVID-19 wave.

Wearable sensors can continuously and passively detect potential respiratory infections before or absent symptoms. However, the population-level impact of deploying these devices during pandemics is unclear. We built a compartmental model of Canada's second COVID-19 wave and simulated wearable sensor deployment scenarios, systematically varying detection algorithm accuracy, uptake, and adherence. With current detection algorithms and 4% uptake, we observed a 16% reduction in the second wave burden of infection; however, 22% of this reduction was attributed to incorrectly quarantining uninfected device users. Improving detection specificity and offering confirmatory rapid tests each minimized unnecessary quarantines and lab-based tests. With a sufficiently low false positive rate, increasing uptake and adherence became effective strategies for scaling averted infections. We concluded that wearable sensors capable of detecting presymptomatic or asymptomatic infections have potential to help reduce the burden of infection during a pandemic; in the case of COVID-19, technology improvements or supporting measures are required to keep social and resource costs sustainable.

Speaking Haptically: From Phonemes to Phrases With a Mobile Haptic Communication System.

In this article, we present three studies involving WhatsHap, a mobile system designed to deliver speech as vibrations on the forearm with minimal hardware demands and practice time. After only 4.2 h of training on a 24-haptic phoneme vocabulary and on how to combine these to form words, participants were able to generalize their phoneme identification skills to the understanding of untrained English words, correctly identifying 65% of words in phrases rendered with a user-controlled interval between words, and up to 59% with a fixed interval. Ultimately, participants were able to complete 88% of simple communicative tasks that elicited spontaneous speech and semi-structured bidirectional conversation using the apparatus. We conclude by providing insights as to how such a system may ultimately be used for communication under more natural conditions.

Ten Little Fingers, Ten Little Toes: Can Toes Match Fingers for Haptic Discrimination?

In comparison with fingers, toes are relatively unexplored candidates for multi-site haptic rendering. This is likely due to their reported susceptibility to erroneous perception of haptic stimuli, owing to their anatomical structure. We hypothesize that this shortcoming can be mitigated by careful design of the tactile encoding to account for the idiosyncrasies of toe perception. Our efforts to design such an encoding achieved an improved perceptual accuracy of 18% for poking and 16% for vibrotactile stimuli. As we demonstrate, in this article, the resulting perceptual accuracy achieved by the proposed tactile encoding approaches that of the fingers, allowing for consideration of the toes as a practical location to render multi-site haptic stimuli.

Getting Your Hands Dirty Outside the Lab: A Practical Primer for Conducting Wearable Vibrotactile Haptics Research.

As haptics have become an ingrained part of our wearable experience, particularly through phones, smartwatches, and fitness trackers, significant research effort has been conducted to find new ways of using wearable haptics to convey information, especially while we are on-the-go. In this paper, instead of focusing on aspects of haptic information design, such as tacton encoding methods, actuators, and technical fabrication of devices, we address the more general recurring issues and "gotchas" that arise when moving from core haptic perceptual studies and in-lab wearable experiments to real world testing of wearable vibrotactile haptic systems. We summarize key issues for practitioners to take into account when designing and carrying out in-the-wild wearable haptic user studies, as well as for user studies in a lab environment that seek to simulate real-world conditions. We include not only examples from published work and commercial sources, but also hard-won illustrative examples derived from issues and failures from our own haptic studies. By providing a broad-based, accessible overview of recurring issues, we expect that both novice and experienced haptic researchers will find suggestions that will improve their own mobile wearable haptic studies.

Stereo Vision: The Haves and Have-Nots.

Animals with front facing eyes benefit from a substantial overlap in the visual fields of each eye, and devote specialized brain processes to using the horizontal spatial disparities produced as a result of viewing the same object with two laterally placed eyes, to derived depth or 3-D stereo information. This provides the advantage to break the camouflage of objects in front of similarly textured background and improves hand eye coordination for grasping objects close at hand. It is widely thought that about 5% of the population have a lazy eye and lack stereo vision, so it is often supposed that most of the population (95%) have good stereo abilities. We show that this is not the case; 68% have good to excellent stereo (the haves) and 32% have moderate to poor stereo (the have-nots). Why so many people lack good 3-D stereo vision is unclear but it is likely to be neural and reversible.

Vibrotactile rendering of splashing fluids.

We introduce the use of vibrotactile feedback as a rendering modality for solid-fluid interaction, based on the physical processes that generate sound during such interactions. This rendering approach enables the perception of vibrotactile feedback from virtual scenarios that resemble the experience of stepping into a water puddle or plunging a hand into a volume of fluid.

The measurement and treatment of suppression in amblyopia.

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current estimates put the prevalence of amblyopia at approximately 1-3%(1-3), the majority of cases being monocular(2). Amblyopia is most frequently caused by ocular misalignment (strabismus), blur induced by unequal refractive error (anisometropia), and in some cases by form deprivation. Although amblyopia is initially caused by abnormal visual input in infancy, once established, the visual deficit often remains when normal visual input has been restored using surgery and/or refractive correction. This is because amblyopia is the result of abnormal visual cortex development rather than a problem with the amblyopic eye itself(4,5) . Amblyopia is characterized by both monocular and binocular deficits(6,7) which include impaired visual acuity and poor or absent stereopsis respectively. The visual dysfunction in amblyopia is often associated with a strong suppression of the inputs from the amblyopic eye under binocular viewing conditions(8). Recent work has indicated that suppression may play a central role in both the monocular and binocular deficits associated with amblyopia(9,10) . Current clinical tests for suppression tend to verify the presence or absence of suppression rather than giving a quantitative measurement of the degree of suppression. Here we describe a technique for measuring amblyopic suppression with a compact, portable device(11,12) . The device consists of a laptop computer connected to a pair of virtual reality goggles. The novelty of the technique lies in the way we present visual stimuli to measure suppression. Stimuli are shown to the amblyopic eye at high contrast while the contrast of the stimuli shown to the non-amblyopic eye are varied. Patients perform a simple signal/noise task that allows for a precise measurement of the strength of excitatory binocular interactions. The contrast offset at which neither eye has a performance advantage is a measure of the "balance point" and is a direct measure of suppression. This technique has been validated psychophysically both in control(13,14) and patient(6,9,11) populations. In addition to measuring suppression this technique also forms the basis of a novel form of treatment to decrease suppression over time and improve binocular and often monocular function in adult patients with amblyopia(12,15,16) . This new treatment approach can be deployed either on the goggle system described above or on a specially modified iPod touch device(15).

Identification of walked-upon materials in auditory, kinesthetic, haptic, and audio-haptic conditions.

Locomotion generates multisensory information about walked-upon objects. How perceptual systems use such information to get to know the environment remains unexplored. The ability to identify solid (e.g., marble) and aggregate (e.g., gravel) walked-upon materials was investigated in auditory, haptic or audio-haptic conditions, and in a kinesthetic condition where tactile information was perturbed with a vibromechanical noise. Overall, identification performance was better than chance in all experimental conditions and for both solids and the better identified aggregates. Despite large mechanical differences between the response of solids and aggregates to locomotion, for both material categories discrimination was at its worst in the auditory and kinesthetic conditions and at its best in the haptic and audio-haptic conditions. An analysis of the dominance of sensory information in the audio-haptic context supported a focus on the most accurate modality, haptics, but only for the identification of solid materials. When identifying aggregates, response biases appeared to produce a focus on the least accurate modality--kinesthesia. When walking on loose materials such as gravel, individuals do not perceive surfaces by focusing on the most accurate modality, but by focusing on the modality that would most promptly signal postural instabilities.

Toward dynamic image mosaic generation with robustness to parallax.

Mosaicing is largely dependent on the quality of registration among the constituent input images. Parallax and object motion present challenges to image registration, leading to artifacts in the result. To reduce the impact of these artifacts, traditional image mosaicing approaches often impose planar scene constraints or rely on purely rotational camera motion or dense sampling. However, these requirements are often impractical or fail to address the needs of all applications. Instead, taking advantage of depth cues and a smooth transition criterion, we achieve significantly improved mosaicing results for static scenes, coping effectively with nontrivial parallax in the input. We extend this approach to the synthesis of dynamic video mosaics, incorporating foreground/background segmentation and a consistent motion perception criterion. Although further additions are required to cope with unconstrained object motion, our algorithm can synthesize a perceptually convincing output, conveying the same appearance of motion as seen in the input sequences.