9 research outputs found
I-Scratch: Independent Slide Creation With Auditory Comment and Haptic Interface for the Blind and Visually Impaired
No full textPresentation software still holds barriers to independent creation for blind and visually impaired users (BVIs) due to its visual-centric interface. To address this gap, we introduce I-Scratch, a multimodal system which empowers BVIs to independently create, explore, and edit PowerPoint slides. We initially designed I-Scratch to tackle the practical challenges faced by BVIs and refined I-Scratch to improve its usability and accessibility through iterative participatory sessions involving a blind user. I-Scratch integrates a graphical tactile display with auditory guidance for multimodal feedback, simplifies the user interface, and leverages AI technologies for visual assistance in image generation and content interpretation. A user study with ten BVIs demonstrated that I-Scratch enables them to produce visually coherent and aesthetically pleasing slides independently, achieving 91.25% of full and partial successes with a CSI score of 85.07. We present five guidelines and future directions to support the creative work of BVIs using presentation software. © 2025 Copyright held by the owner/author(s)
Designing Distinguishable Mid-Air Ultrasound Tactons with Temporal Parameters
No full textMid-air ultrasound technology offers new design opportunities for contactless
tactile patterns (i.e., Tactons) in user applications. Yet, few guidelines
exist for making ultrasound Tactons easy to distinguish for users. In this
paper, we investigated the distinguishability of temporal parameters of
ultrasound Tactons in five studies (n=72 participants). Study 1 established the
discrimination thresholds for amplitude-modulated (AM) frequencies. In Studies
2-5, we investigated distinguishable ultrasound Tactons by creating four Tacton
sets based on mechanical vibrations in the literature and collected similarity
ratings for the ultrasound Tactons. We identified a subset of temporal
parameters, such as rhythm and low envelope frequency, that could create
distinguishable ultrasound Tactons. Also, a strong correlation (mean Spearman's
=0.75) existed between similarity ratings for ultrasound Tactons and
similarities of mechanical Tactons from the literature, suggesting vibrotactile
designers can transfer their knowledge to ultrasound design. We present design
guidelines and future directions for creating distinguishable mid-air
ultrasound Tactons
An Interactive Tool for Simulating Mid-Air Ultrasound Tactons on the Skin
No full textMid-air ultrasound haptic technology offers a myriad of temporal and spatial
parameters for contactless haptic design. Yet, predicting how these parameters
interact to render an ultrasound signal is difficult before testing them on a
mid-air ultrasound haptic device. Thus, haptic designers often use a
trial-and-error process with different parameter combinations to obtain desired
tactile patterns (i.e., Tactons) for user applications. We propose an
interactive tool with five temporal and three spatiotemporal design parameters
that can simulate the temporal and spectral properties of stimulation at
specific skin points. As a preliminary verification, we measured vibrations
induced from the ultrasound Tactons varying on one temporal and two
spatiotemporal parameters. The measurements and simulation showed similar
results for three different ultrasound rendering techniques, suggesting the
efficacy of the simulation tool. We present key insights from the simulation
and discuss future directions for enhancing the capabilities of simulations
Emotional and sensory ratings of vibration Tactons in the lab and crowdsourced settings
No full textVibrotactile actuators in consumer devices present new opportunities to crowdsource subjective ratings of tactile icons (i.e., Tactons). Yet, little is known about the effects of user demographics, hardware form factors, and study environments on subjective ratings. Also, the feasibility of crowdsourcing emotional and sensory ratings remains underexplored. To address this gap, we investigated valence, arousal, and roughness ratings by controlling for the Tacton design approach, biological sex, form factor, and study environment. Study 1 investigated the effects of two biological sexes and three smartphone models on the ratings from 36 participants in a controlled laboratory setting using two sets of 24 Tactons (48 in total) created using different design approaches. Strong correlations (mean Pearson's r=0.86) existed in all ratings across biological sexes regardless of Tacton sets, while valence ratings showed moderate or low correspondence across smartphone models depending on Tacton set. In Study 2, we crowdsourced the Tacton ratings with 36 new participants to explore the impact of an uncontrolled setting on the results. We identified a subset of parameters, such as duration, that were influenced by the settings, where demographics and form factors varied. Also, arousal and roughness ratings demonstrated strong correspondences with 85% and 77% of statistically equivalent Tactons between the lab and crowdsourced settings, but valence ratings showed moderate to strong correlations depending on Tacton design approaches. Based on these findings, we offer guidelines for Tacton design in uncontrolled settings and for crowdsourcing emotional and sensory ratings. © 2025 Elsevier LtdFALSEsciessciscopu
Vibrotactile Similarity Perception in Crowdsourced and Lab Studies
No full textCrowdsourcing can enable rapid data collection for haptics research, yet little is known about its validity in comparison to controlled lab experiments. Furthermore, no data exists on how different smartphone platforms impact the crowdsourcing results. To answer these questions, we conducted four vibrotactile (VT) similarity perception studies on iOS and Android smartphones in the lab and through Amazon Mechanical Turk (MTurk). Participants rated the pairwise similarities of 14 rhythmic VT patterns on their smartphones or a lab device. The similarity ratings from the lab and MTurk experiments suggested a very strong correlation for iOS devices (rs= 0.9 ) and a lower but still strong correlation for Android phones (rs= 0.68 ). In addition, we found a stronger correlation between the crowdsourced iOS and Android ratings (rs= 0.78 ) compared to the correlation between the iOS and Android data in the lab (rs= 0.65 ). We provide further insights into these correlations using the perceptual spaces obtained from the four datasets. Our results provide preliminary evidence for the validity of crowdsourced VT similarity studies, especially on iOS devices.</p
Comparing the effectiveness of bivalent and monovalent COVID-19 vaccines against COVID-19 infection during the winter season of 2022-2023: A real-world retrospective observational matched cohort study in the Republic of Korea
No full textObjectives: To compare the effectiveness of bivalent and monovalent COVID-19 vaccines throughout the 2022-2023 winter season based on real-world data. Methods: This retrospective observational matched cohort study used the national vaccination program and a surveillance dataset from the Republic of Korea, and included adults aged >18 years who received bivalent or monovalent COVID-19 vaccines between October 11, 2022, and December 17, 2022. Cox proportional hazard models were used to estimate the hazard ratio for COVID-19 infection between the groups. Results: We included 29,245 matched individuals in the bivalent and monovalent vaccine groups, respectively. The bivalent vaccine recipients showed 12.2% (95% confidence interval [CI] 6.5-17.7%) additional protection against COVID-19 infection compared with the monovalent vaccine recipients. The additional protection provided by bivalent vaccines was significantly higher among residents of long-term care facilities (39.4%, 95% CI 21.6-53.1%). Maximum additional protection was observed 3 to 4 months after completing the vaccination (17.6%, 95% CI 6.6-27.3%). Conclusion: Bivalent COVID-19 vaccines showed significantly better protection against infection than monovalent vaccines among adults during the 2022-2023 winter season. Our results highlight that immunization programs with bivalent vaccines comprising recent variants can be an effective measure to prepare for seasonal COVID-19 circulation
Global prevalence, cascade of care, and prophylaxis coverage of hepatitis B in 2022: a modelling study
No full textGlobal change in hepatitis C virus prevalence and cascade of care between 2015 and 2020: a modelling study
No full textBackground Since the release of the first global hepatitis elimination targets in 2016, and until the COVID-19 pandemic started in early 2020, many countries and territories were making progress toward hepatitis C virus (HCV) elimination. This study aims to evaluate HCV burden in 2020, and forecast HCV burden by 2030 given current trends.
Methods This analysis includes a literature review, Delphi process, and mathematical modelling to estimate HCV prevalence (viraemic infection, defined as HCV RNA-positive cases) and the cascade of care among people of all ages (age ≥0 years from birth) for the period between Jan 1, 2015, and Dec 31, 2030. Epidemiological data were collected from published sources and grey literature (including government reports and personal communications) and were validated among country and territory experts. A Markov model was used to forecast disease burden and cascade of care from 1950 to 2050 for countries and territories with data. Model outcomes were extracted from 2015 to 2030 to calculate population-weighted regional averages, which were used for countries or territories without data. Regional and global estimates of HCV prevalence, cascade of care, and disease burden were calculated based on 235 countries and territories.
Findings Models were built for 110 countries or territories: 83 were approved by local experts and 27 were based on published data alone. Using data from these models, plus population-weighted regional averages for countries and territories without models (n=125), we estimated a global prevalence of viraemic HCV infection of 0·7% (95% UI 0·7–0·9), corresponding to 56·8 million (95% UI 55·2–67·8) infections, on Jan 1, 2020. This number represents a decrease of 6·8 million viraemic infections from a 2015 (beginning of year) prevalence estimate of 63·6 million (61·8–75·8) infections (0·9% [0·8–1·0] prevalence). By the end of 2020, an estimated 12·9 million (12·5–15·4) people were living with a diagnosed viraemic infection. In 2020, an estimated 641000 (623000–765000) patients initiated treatment.
Interpretation At the beginning of 2020, there were an estimated 56·8 million viraemic HCV infections globally. Although this number represents a decrease from 2015, our forecasts suggest we are not currently on track to achieve global elimination targets by 2030. As countries recover from COVID-19, these findings can help refocus efforts aimed at HCV elimination
Global prevalence, cascade of care, and prophylaxis coverage of hepatitis B in 2022 : a modelling study
No full textAbstract: Background: The 2016 World Health Assembly endorsed the elimination of hepatitis B virus (HBV) infection as a public health threat by 2030; existing therapies and prophylaxis measures make such elimination feasible, even in the absence of a virological cure. We aimed to estimate the national, regional, and global prevalence of HBV in the general population and among children aged 5 years and younger, as well as the rates of diagnosis, treatment, prophylaxis, and the future burden globally. Methods: In this modelling study, we used a Delphi process with data from literature reviews and interviews with country experts to quantify the prevalence, diagnosis, treatment, and prevention measures for HBV infection. The PRoGReSs Model, a dynamic Markov model, was used to estimate the country, regional, and global prevalence of HBV infection in 2022, and the effects of treatment and prevention on disease burden. The future incidence of morbidity and mortality in the absence of additional interventions was also estimated at the global level. Findings: We developed models for 170 countries which resulted in an estimated global prevalence of HBV infection in 2022 of 3\ub72% (95% uncertainty interval 2\ub77\u20134\ub70), corresponding to 257\ub75 million (216\ub76\u2013316\ub74) individuals positive for HBsAg. Of these individuals, 36\ub70 million were diagnosed, and only 6\ub78 million of the estimated 83\ub73 million eligible for treatment were on treatment. The prevalence among children aged 5 years or younger was estimated to be 0\ub77% (0\ub76\u20131\ub70), corresponding to 5\ub76 million (4\ub75\u20137\ub78) children with HBV infection. Based on the most recent data, 85% of infants received three-dose HBV vaccination before 1 year of age, 46% had received a timely birth dose of vaccine, and 14% received hepatitis B immunoglobulin along with the full vaccination regimen. 3% of mothers with a high HBV viral load received antiviral treatment to reduce mother-to-child transmission
