13 research outputs found

    Evaluation of reaction times to sound stimuli on mobile devices

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    Presented at the 21st International Conference on Auditory Display (ICAD2015), July 6-10, 2015, Graz, Styria, Austria.When developing new devices for assistive technology, it is important to consider auditory response times to different kinds of warning and navigational sounds. Perception, processing and action following the presentation of auditory stimuli depends on several parameters, the most important being the stimuli themselves and the method used for providing feedback. With the growing market penetration of mobile devices (smartphones, tablets etc.) and increasing popularity of crowdsourced solutions, we have chosen to develop a mobile application for the measurement of reaction times with respect to a wide range of stimuli, including sine tones, speech and various kinds of clicks and noises. During tests, participants are asked to indicate the direction of sound samples by pressing the appropriate button on the touch screen. Stereo panning can be used up to five directions. In this paper, our goal is to demonstrate the viability of this approach through a set of basic (at this time, not yet crowdsourced) tests performed using the application. A rudimentary statistical evaluation of measured response times and success rates was performed. Results were compared to an earlier study using similar categories of stimuli. As in that study, some relative differences between the stimuli types were found, i.e. the 1 kHz panned sine and pink noise categories were shown to be somewhat more favorable than speech and click-trains. Future enhancements to the application will include tilt-based input control – allowing for the participation of visually impaired test subjects who cannot see the response buttons – as well as extensions allowing for the logging and analysis of large-scale crowdsourced test results

    A colorimetry based, semi-automated portable sensor device for the detection of arsenic in drinking water

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    A portable colorimetric device is presented for arsenic ion detection in drinking water. The main purpose of this device – which was developed to complement a commercial water dearsenating station demanding regular (weekly to monthly) regeneration runs depending on its saturation – is to provide regular field measurements and easy, semi-automatic operation designed specifically for untrained, typically illiterate users e.g. the population of developing countries. The device exploits a commercially available, well established reagent kit, which is widely used in arsenic field-testing in many developing countries. The hereby presented custom-designed microfluidic system enhances the user-friendliness, the functionality and reliability of the test-strip based kit. The response for total inorganic arsenic ion concentrations (As(III) and As(V)) is linear in the 5-20 μg/l (ppb) range with a sensitivity of 1 μg/l, thus the device is capable to distinguish drinkable water based on the World Health Organization (WHO) guidelines of 10 μg/l. The average relative standard deviation of the measurements is 8 % in the linear range and it is below 2 % for higher arsenic concentrations (above 20 μg/l). The hardware construction of the device and the custom microfluidic system is presented in detail. The effect of elevated water sample temperature on the kinetics and performance of the device was also investigated in order to reduce the required time for the measurements. Stable and reliable arsenic concentration values were obtained after 60 min at 22 oC (ambient temperature) and after only 25 min at 50 oC water sample temperature, but at a cost of an increased relative standard deviation to 16 %, in the linear range

    Improving the Audio Game-Playing Performances of People with Visual Impairments Through Multimodal Training

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    As the number of people with visual impairments (that is, those who are blind or have low vision) is continuously increasing, rehabilitation and engineering researchers have identified the need to design sensorysubstitution devices that would offer assistance and guidance to these people for performing navigational tasks. Auditory and haptic cues have been shown to be an effective approach towards creating a rich spatial representation of the environment, so they are considered for inclusion in the development of assistive tools that would enable people with visual impairments to acquire knowledge of the surrounding space in a way close to the visually based perception of sighted individuals. However, achieving efficiency through a sensory substitution device requires extensive training for visually impaired users to learn how to process the artificial auditory cues and convert them into spatial information. Methods: Considering all the potential advantages gamebased learning can provide, we propose a new method for training sound localization and virtual navigational skills of visually impaired people in a 3D audio game with hierarchical levels of difficulty. The training procedure is focused on a multimodal (auditory and haptic) learning approach in which the subjects have been asked to listen to 3D sounds while simultaneously perceiving a series of vibrations on a haptic headband that corresponds to the direction of the sound source in space. Results: The results we obtained in a sound-localization experiment with 10 visually impaired people showed that the proposed training strategy resulted in significant improvements in auditory performance and navigation skills of the subjects, thus ensuring behavioral gains in the spatial perception of the environment.Sound of Vision, Horizon 2020 nr. 643636Peer Reviewe

    A survey of assistive technologies and applications for blind users on mobile platforms: a review and foundation for research

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    This paper summarizes recent developments in audio and tactile feedback based assistive technologies targeting the blind community. Current technology allows applications to be efficiently distributed and run on mobile and handheld devices, even in cases where computational requirements are significant. As a result, electronic travel aids, navigational assistance modules, text-to-speech applications, as well as virtual audio displays which combine audio with haptic channels are becoming integrated into standard mobile devices. This trend, combined with the appearance of increasingly user- friendly interfaces and modes of interaction has opened a variety of new perspectives for the rehabilitation and training of users with visual impairments. The goal of this paper is to provide an overview of these developments based on recent advances in basic research and application development. Using this overview as a foundation, an agenda is outlined for future research in mobile interaction design with respect to users with special needs, as well as ultimately in relation to sensor-bridging applications in genera

    EASY-APP : An artificial intelligence model and application for early and easy prediction of severity in acute pancreatitis

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    Acute pancreatitis (AP) is a potentially severe or even fatal inflammation of the pancreas. Early identification of patients at high risk for developing a severe course of the disease is crucial for preventing organ failure and death. Most of the former predictive scores require many parameters or at least 24 h to predict the severity; therefore, the early therapeutic window is often missed.The early achievable severity index (EASY) is a multicentre, multinational, prospective and observational study (ISRCTN10525246). The predictions were made using machine learning models. We used the scikit-learn, xgboost and catboost Python packages for modelling. We evaluated our models using fourfold cross-validation, and the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), and accuracy metrics were calculated on the union of the test sets of the cross-validation. The most critical factors and their contribution to the prediction were identified using a modern tool of explainable artificial intelligence called SHapley Additive exPlanations (SHAP).The prediction model was based on an international cohort of 1184 patients and a validation cohort of 3543 patients. The best performing model was an XGBoost classifier with an average AUC score of 0.81 ± 0.033 and an accuracy of 89.1%, and the model improved with experience. The six most influential features were the respiratory rate, body temperature, abdominal muscular reflex, gender, age and glucose level. Using the XGBoost machine learning algorithm for prediction, the SHAP values for the explanation and the bootstrapping method to estimate confidence, we developed a free and easy-to-use web application in the Streamlit Python-based framework (http://easy-app.org/).The EASY prediction score is a practical tool for identifying patients at high risk for severe AP within hours of hospital admission. The web application is available for clinicians and contributes to the improvement of the model

    Haptic-auditory perceptual feedback based training for improving the spatial acoustic resolution of the visually impaired people

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    Presented at the 21st International Conference on Auditory Display (ICAD2015), July 6-10, 2015, Graz, Styria, Austria.3D binaural sounds play an important role in the development of navigational systems for the blind people. The use of generic HRTFs in virtual auditory displays significantly affects the acoustic spatial resolution and the listener’s ability to make localization judgments regarding the sound sources situated inside the cone of confusion. The aim of this paper is to investigate whether haptic-auditory feedback based training can enhance sound localization performance, front-back discrimination and the navigational skills of the visually impaired people. In our experiments, we assessed the sound localization performance of nine visually impaired subjects before and after a series of haptic-auditory training procedures aimed to enhance the perception of 3D sounds. The results of our tests demonstrate that our subjects succeeded to improve their sound localization performance, reduced the incidence of angular precision and reversal errors and became able to build an effective spatial representation map of the acoustic environment

    Prevalence and correlates of aggressive behavior in psychiatric inpatient populations

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    Aggressive behavior in patients with psychiatric disorders is attracting increasing research interest. One reason for this is that psychiatric patients are generally considered more likely to be aggressive, which raises a related question of whether diagnoses of psychiatric disorders predict the prevalence of aggressive behavior. Predicting aggression in psychiatric wards is crucial, because aggressive behavior not only endangers the safety of both patients and staff, but it also extends the hospitalization times. Predictions of aggressive behavior also need careful attention to ensure effective treatment planning. This literature review explores the relationship between aggressive behavior and psychiatric disorders and syndromes (dementia, psychoactive substance use, acute psychotic disorder, schizophrenia, bipolar affective disorder, major depressive disorder, obsessive-compulsive disorder, personality disorders and intellectual disability). The prevalence of aggressive behavior and its underlying risk factors, such as sex, age, comorbid psychiatric disorders, socioeconomic status, and history of aggressive behavior are discussed as these are the components that mostly contribute to the increased risk of aggressive behavior. Measurement tools commonly used to predict and detect aggressive behavior and to differentiate between different forms of aggressive behavior in both research and clinical practice are also reviewed. Successful aggression prevention programs can be developed based on the current findings of the correlates of aggressive behavior in psychiatric patients

    Total 25-Hydroxyvitamin D Is an Independent Marker of Left Ventricular Ejection Fraction in Heart Failure with Reduced and Mildly Reduced Ejection Fraction

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    Vitamin D emerged as an important prognostic biomarker in heart failure (HF), with currently highly debated therapeutic implications. Several trials on vitamin D supplementation in HF showed improvements in left ventricular (LV) remodeling and function and health-related quality of life (HRQoL), which did not translate into mid- to long-term beneficial effects regarding physical performance and mortality. We addressed total 25-hydroxyvitamin D (25(OH)D), serum albumin, and uric acid (UA) levels, focusing mainly on vitamin D deficiency, as potential markers of LV systolic dysfunction in HF with reduced and mildly reduced ejection fraction (HFrEF, HFmrEF). Seventy patients with LVEF p = 0.008, p = 0.009, and p = 0.001). Serum UA (7.4 ± 2.4 vs. 5.7 ± 2.1, p = 0.005), NT-proBNP levels (1090.4 (675.2–2664.9) vs. 759.0 (260.3–1474.8), p = 0.034), and MLHFQ scores (21.0 (14.0–47.0) vs. 14.5 (4.5–25.5), p = 0.012) were significantly higher, whereas 25(OH)D concentrations (17.6 (15.1–28.2) vs. 22.7 (19.5–33.8), p = 0.010) were lower in subjects with severely reduced LVEF. Also, 25(OH)D was independently associated with LVEF in univariate and multiple regression analysis, maintaining its significance even after adjusting for confounders such as age, NT-proBNP, the presence of chronic coronary syndrome, hypertension, and anemia. According to our current findings, 25(OH)D is closely associated with LVEF, further supporting the need to establish correct vitamin D supplementation schemes and dietary interventions in HF. The changes in LVEF, 25(OH)D, serum UA, and albumin levels in HFrEF and HFmrEF indicate a similar pathophysiological background
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