Tactile Roughness Perception of Virtual Gratings by Electrovibration

Realistic display of tactile textures on touch screens is a big step forward for haptic technology to reach a wide range of consumers utilizing electronic devices on a daily basis. Since the texture topography cannot be rendered explicitly by electrovibration on touch screens, it is important to understand how we perceive the virtual textures displayed by friction modulation via electrovibration. We investigated the roughness perception of real gratings made of plexiglass and virtual gratings displayed by electrovibration through a touch screen for comparison. In particular, we conducted two psychophysical experiments with 10 participants to investigate the effect of spatial period and the normal force applied by finger on roughness perception of real and virtual gratings in macro size. We also recorded the contact forces acting on the participants' finger during the experiments. The results showed that the roughness perception of real and virtual gratings are different. We argue that this difference can be explained by the amount of fingerpad penetration into the gratings. For real gratings, penetration increased tangential forces acting on the finger, whereas for virtual ones where skin penetration is absent, tangential forces decreased with spatial period. Supporting our claim, we also found that increasing normal force increases the perceived roughness of real gratings while it causes an opposite effect for the virtual gratings. These results are consistent with the tangential force profiles recorded for both real and virtual gratings. In particular, the rate of change in tangential force ($dF_t/dt$) as a function of spatial period and normal force followed trends similar to those obtained for the roughness estimates of real and virtual gratings, suggesting that it is a better indicator of the perceived roughness than the tangential force magnitude.Comment: Manuscript received June 25, 2019; revised November 15, 2019; accepted December 11, 201

A Novel Texture Rendering Approach for Electrostatic Displays

International audienceGenerating realistic texture feelings on tactile displays using data- driven methods has attracted a lot of interest in the last decade. However, the need for large data storages and transmission rates complicates the use of these methods for the future commercial displays. In this paper, we propose a new texture rendering approach which can compress the texture data significantly for electrostatic displays. Using three sample surfaces, we first explain how to record, analyze and compress the texture data, and render them on a touchscreen. Then, through psychophysical experiments conducted with nineteen participants, we show that the textures can be reproduced by a significantly less number of frequency components than the ones in the original signal without inducing perceptual degradation. Moreover, our results indicate that the possible degree of compression is affected by the surface properties

ThermoSurf: Thermal display technology for dynamic and multi-finger interactions

Thermal feedback has been proven to enhance user experience in human-machine interactions. Yet state-of-the-art thermal technology has focused on the single finger or palm in static contact, overlooking dynamic and multi-finger interactions. The underlying challenges include incompatible designs of conventional interfaces for providing salient thermal stimuli for such interactions and, thereby, a lack of knowledge on human thermal perception for relevant conditions. Here we present the ThermoSurf, a new thermal display technology that can deliver temperature patterns on a large interface suitable for dynamic and multi-finger interactions. We also investigate how user exploration affects the perception of the generated temperature distributions. Twenty-three human participants interacted with the device following three exploration conditions (static-single finger, dynamic-single finger, and static-multi finger) and evaluated 15 temperature differences ranging from +1.5 to -7.5 Celcius. Our results showed that human sensitivity against thermal stimuli is significantly greater for static single finger contact compared to the other tested conditions. In addition, this interaction type resulted in higher thermal discrimination thresholds than the ones reported in the literature. Our findings offer new perspectives on providing salient and consistent thermal feedback for future tactile interfaces. </p

A case of Mondini dysplasia with recurrent Streptococcus pneumoniae meningitis

WOS: 000271404800019PubMed ID: 19259698Mondini's dysplasia is a developmental anomaly of the middle ear characterized by cochlear malformation with dilation of the vestibular aquaduct, vestibule, and ampullar ends of the semicircular canals. These deformities may result in a connection between subarachnoid space and the middle ear resulting in recurrent episodes of meningitis. Additionally, it is commonly associated with hearing impairment. We describe here a boy with recurrent meningitis and unilateral sensorineural hearing loss. Mondini dysplasia was demonstrated with computed tomographic scans of the temporal bones in the search for pathogenesis of recurrent meningitis

Comparison of NERD patients with and without laryngopharyngeal reflux symptoms according to 24-hour ambulatory intraesophageal pH-impedance values

WOS: 00038677600004

The diagnostic value of 24-hour ambulatory intraesophageal pH-impedance in patients with laryngopharyngeal reflux symptoms comparable with typical symptoms

WOS: 000405291100003PubMed ID: 28815026Background: The diagnosis of laryngopharyngeal reflux is currently based on a combination of the patient history of multichannel intraluminal impedance and ambulatory pH (MII-pH); however, none of these findings alone is specific for the diagnosis of laryngopharyngeal reflux. We aimed to compare the baseline characteristics and esophageal baseline impedance values between patients with and without laryngopharyngeal reflux symptoms. Methods: We retrospectively analyzed data from two groups of patients with laryngopharyngeal reflux according to their reflux finding score (RFS) as scored by ENTs. Control patients were nonerosive reflux disease patients without laryngopharyngeal reflux. All MII-pH parameters and baseline impedance were analyzed from six levels and the proximal and distal baseline impedance and the ratio of the proximal to distal baseline impedance levels was calculated. Results: Altogether 123 patients with laryngopharyngeal reflux and 49 control patients were included. A total of 81 of 123 patients had RFS >= 7, and 42 of 123 patients had RFS > 7. Baseline impedance analysis showed that patients with laryngopharyngeal reflux symptoms had significantly lower proximal baseline impedance values (1997 +/- 51 vs 2245 +/- 109, p = 7 (3.85 +/- 0.65 vs 8.2 +/- 1.52, p < 0.05) or the control group (3.85 +/- 0.65 vs 6.1 +/- 0.81, p < 0.05). Additionally, patients with RFS7 had significantly lower proximal baseline impedance levels than the control group (1970 +/- 63 vs 2245 +/- 109, p < 0.05). Conclusions: Patients with pathologic laryngopharyngeal reflux symptom scores had lower proximal baseline impedance levels and lower proximal-to-distal ratios, which may reflect the proximal mucosal noxious effect of the refluxate. These results may indicate that laryngopharyngeal reflux symptoms may be due to chronic acid exposure in the proximal segments of the esophagus, and the proximal-to-distal ratio may be used as a new metric for diagnosis