329 research outputs found

    Automatic speech analysis to early detect functional cognitive decline in elderly population

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    This study aimed at evaluating whether people with a normal cognitive function can be discriminated from subjects with a mild impairment of cognitive function based on a set of acoustic features derived from spontaneous speech. Voice recordings from 90 Italian subjects (age >65 years; group 1: 47 subjects with MMSE>26; group 2: 43 subjects with 20≀ MMSE ≀26) were collected. Voice samples were processed using a MATLAB-based custom software to derive a broad set of known acoustic features. Linear mixed model analyses were performed to select the features able to significantly distinguish between groups. The selected features (% of unvoiced segments, duration of unvoiced segments, % of voice breaks, speech rate, and duration of syllables), alone or in addition to age and years of education, were used to build a learning-based classifier. The leave-one-out cross validation was used for testing and the classifier accuracy was computed. When the voice features were used alone, an overall classification accuracy of 0.73 was achieved. When age and years of education were additionally used, the overall accuracy increased up to 0.80. These performances were lower than the accuracy of 0.86 found in a recent study. However, in that study the classification was based on several tasks, including more cognitive demanding tasks. Our results are encouraging because acoustic features, derived for the first time only from an ecologic continuous speech task, were able to discriminate people with a normal cognitive function from people with a mild cognitive decline. This study poses the basis for the development of a mobile application performing automatic voice analysis on-the-fly during phone calls, which might potentially support the detection of early signs of functional cognitive decline

    Conceptualising a Dynamic Technology Practice in Education Using Argyris and Schön's Theory of Action

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    Despite substantial national effort to integrate technology in education, it seems that practitioners in the education system are not working in line with the given policy. Evidence from large-scale studies of students’ technology practices at school over the last decade show disparities in student practices. The observed gap between the micro and the macro level call for a closer exploration. Research that explores the influence of social and organizational factors may be useful for understanding the processes behind such gaps. Argyris and Schön’s ‘Theory of Action’ (1978) is proposed as an example of an organizational theory that can be adopted in educational technology research to move towards understanding the complexities of technology practice. To encourage discourse and application of Argyris and Schön’s theory in the field of educational technology research, this paper introduces the theory, a review of its empirical application in research of teacher educations’ technology practice and relevant conceptual work. The paper presents a conceptual framework based on Argyris and Schön’s theory that has been developed through two recent studies, and invites its application in future research and development

    Towards a comprehensive evaluation of ultrasound speckle reduction

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    Over the last three decades, several despeckling filters have been developed to reduce the speckle noise inherently present in ultrasound images without losing the diagnostic information. In this paper, a new intensity and feature preservation evaluation metric for full speckle reduction evaluation is proposed based contrast and feature similarities. A comparison of the despeckling methods is done, using quality metrics and visual interpretation of images profiles to evaluate their performance and show the benefits each one can contribute to noise reduction and feature preservation. To test the methods, noise-free images and simulated B-mode ultrasound images are used. This way, the despeckling techniques can be compared using numeric metrics, taking the noise-free image as a reference. In this study, a total of seventeen different speckle reduction algorithms have been documented based on adaptive filtering, diffusion filtering and wavelet filtering, with sixteen qualitative metrics estimation.info:eu-repo/semantics/publishedVersio

    Effect of portable noninvasive ventilation on thoracoabdominal volumes in recovery from intermittent exercise in patients with COPD

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    We previously showed that use of portable noninvasive ventilation (pNIV) during recovery periods within intermittent exercise improved breathlessness and exercise tolerance in patients with COPD compared with pursed-lip breathing (PLB). However, in a minority of patients recovery from dynamic hyperinflation (DH) was better with PLB, based on inspiratory capacity. We further explored this using Optoelectronic Plethysmography to assess total and compartmental thoracoabdominal volumes. Fourteen patients with COPD (means ± SD) (FEV1: 55% ± 22% predicted) underwent, in a balanced order sequence, two intermittent exercise protocols on the cycle ergometer consisting of five repeated 2-min exercise bouts at 80% peak capacity, separated by 2-min recovery periods, with application of pNIV or PLB in the 5 min of recovery. Our findings identified seven patients showing recovery in DH with pNIV (DH responders) whereas seven showed similar or better recovery in DH with PLB. When pNIV was applied, DH responders compared with DH nonresponders exhibited greater tidal volume (by 0.8 ± 0.3 L, P = 0.015), inspiratory flow rate (by 0.6 ± 0.5 L/s, P = 0.049), prolonged expiratory time (by 0.6 ± 0.5 s, P = 0.006), and duty cycle (by 0.7 ± 0.6 s, P = 0.007). DH responders showed a reduction in end-expiratory thoracoabdominal DH (by 265 ± 633 mL) predominantly driven by reduction in the abdominal compartment (by 210 ± 494 mL); this effectively offset end-inspiratory rib-cage DH. Compared with DH nonresponders, DH responders had significantly greater body mass index (BMI) by 8.4 ± 3.2 kg/m2, P = 0.022 and tended toward less severe resting hyperinflation by 0.3 ± 0.3 L. Patients with COPD who mitigate end-expiratory rib-cage DH by expiratory abdominal muscle recruitment benefit from pNIV application. NEW & NOTEWORTHY Compared with the pursed-lip breathing technique, acute application of portable noninvasive ventilation during recovery from intermittent exercise improved end-expiratory thoracoabdominal dynamic hyperinflation (DH) in 50% of patients with COPD (DH responders). DH responders, compared with DH nonresponders, exhibited a reduction in end-expiratory thoracoabdominal DH predominantly driven by the abdominal compartment that effectively offset end-expiratory rib cage DH. The essential difference between DH responders and DH nonresponders was, therefore, in the behavior of the abdomen

    Carotid Ultrasound Boundary Study (CUBS): An Open Multicenter Analysis of Computerized Intima–Media Thickness Measurement Systems and Their Clinical Impact

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    Common carotid intima–media thickness (CIMT) is a commonly used marker for atherosclerosis and is often computed in carotid ultrasound images. An analysis of different computerized techniques for CIMT measurement and their clinical impacts on the same patient data set is lacking. Here we compared and assessed five computerized CIMT algorithms against three expert analysts’ manual measurements on a data set of 1088 patients from two centers. Inter- and intra-observer variability was assessed, and the computerized CIMT values were compared with those manually obtained. The CIMT measurements were used to assess the correlation with clinical parameters, cardiovascular event prediction through a generalized linear model and the Kaplan–Meier hazard ratio. CIMT measurements obtained with a skilled analyst's segmentation and the computerized segmentation were comparable in statistical analyses, suggesting they can be used interchangeably for CIMT quantification and clinical outcome investigation. To facilitate future studies, the entire data set used is made publicly available for the community at http://dx.doi.org/10.17632/fpv535fss7.1

    The Sound Sensation of Apical Electric Stimulation in Cochlear Implant Recipients with Contralateral Residual Hearing

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    BACKGROUND: Studies using vocoders as acoustic simulators of cochlear implants have generally focused on simulation of speech understanding, gender recognition, or music appreciation. The aim of the present experiment was to study the auditory sensation perceived by cochlear implant (CI) recipients with steady electrical stimulation on the most-apical electrode. METHODOLOGY/PRINCIPAL FINDINGS: Five unilateral CI users with contralateral residual hearing were asked to vary the parameters of an acoustic signal played to the non-implanted ear, in order to match its sensation to that of the electric stimulus. They also provided a rating of similarity between each acoustic sound they selected and the electric stimulus. On average across subjects, the sound rated as most similar was a complex signal with a concentration of energy around 523 Hz. This sound was inharmonic in 3 out of 5 subjects with a moderate, progressive increase in the spacing between the frequency components. CONCLUSIONS/SIGNIFICANCE: For these subjects, the sound sensation created by steady electric stimulation on the most-apical electrode was neither a white noise nor a pure tone, but a complex signal with a progressive increase in the spacing between the frequency components in 3 out of 5 subjects. Knowing whether the inharmonic nature of the sound was related to the fact that the non-implanted ear was impaired has to be explored in single-sided deafened patients with a contralateral CI. These results may be used in the future to better understand peripheral and central auditory processing in relation to cochlear implants

    Games for active ageing, wellbeing and quality of life: A pilot study

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    The goal of this study is to identify a set of psychosocial variables and design domains important for game designers to encourage active ageing, well-being and quality of life. Sixty adult learners at four universities of third age were randomly assigned to three groups: the experimental group (G1), who tested firstly a game-based learning platform (GBLP) and then a computer-assisted platform (CAP); the comparison group (G2), who tested firstly the CAP and then the GBLP and the control group (G3) that did not take part in the intervention. Participants were assessed on their health-related well-being and quality of life, using the SF36v2 and WHOQOL-BREF scales before and after each experiment. Findings suggest that there were differences between the group type and their perception on mental health (F(2,57) = 3.771, p =.029) and general health-related well-being (F(2,57) = 5.231, p =.008), in which the GBLP showed improvements relative to the CAP. The environment and mental health were some of the psychosocial domains that should be considered, whereas storytelling, context-aware challenges, game space, immediate feedback, role-playing and social engagement were relevant design domains for these games

    Sensitivity of the human auditory cortex to acoustic degradation of speech and non-speech sounds

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    The perception of speech is usually an effortless and reliable process even in highly adverse listening conditions. In addition to external sound sources, the intelligibility of speech can be reduced by degradation of the structure of speech signal itself, for example by digital compression of sound. This kind of distortion may be even more detrimental to speech intelligibility than external distortion, given that the auditory system will not be able to utilize sound source-specific acoustic features, such as spatial location, to separate the distortion from the speech signal. The perceptual consequences of acoustic distortions on speech intelligibility have been extensively studied. However, the cortical mechanisms of speech perception in adverse listening conditions are not well known at present, particularly in situations where the speech signal itself is distorted. The aim of this thesis was to investigate the cortical mechanisms underlying speech perception in conditions where speech is less intelligible due to external distortion or as a result of digital compression. In the studies of this thesis, the intelligibility of speech was varied either by digital compression or addition of stochastic noise. Cortical activity related to the speech stimuli was measured using magnetoencephalography (MEG). The results indicated that degradation of speech sounds by digital compression enhanced the evoked responses originating from the auditory cortex, whereas addition of stochastic noise did not modulate the cortical responses. Furthermore, it was shown that if the distortion was presented continuously in the background, the transient activity of auditory cortex was delayed. On the perceptual level, digital compression reduced the comprehensibility of speech more than additive stochastic noise. In addition, it was also demonstrated that prior knowledge of speech content enhanced the intelligibility of distorted speech substantially, and this perceptual change was associated with an increase in cortical activity within several regions adjacent to auditory cortex. In conclusion, the results of this thesis show that the auditory cortex is very sensitive to the acoustic features of the distortion, while at later processing stages, several cortical areas reflect the intelligibility of speech. These findings suggest that the auditory system rapidly adapts to the variability of the auditory environment, and can efficiently utilize previous knowledge of speech content in deciphering acoustically degraded speech signals.Puheen havaitseminen on useimmiten vaivatonta ja luotettavaa myös erittÀin huonoissa kuunteluolosuhteissa. Puheen ymmÀrrettÀvyys voi kuitenkin heikentyÀ ympÀristön hÀiriölÀhteiden lisÀksi myös silloin, kun puhesignaalin rakennetta muutetaan esimerkiksi pakkaamalla digitaalista ÀÀntÀ. TÀllainen hÀiriö voi heikentÀÀ ymmÀrrettÀvyyttÀ jopa ulkoisia hÀiriöitÀ voimakkaammin, koska kuulojÀrjestelmÀ ei pysty hyödyntÀmÀÀn ÀÀnilÀhteen ominaisuuksia, kuten ÀÀnen tulosuuntaa, hÀiriön erottelemisessa puheesta. Akustisten hÀiriöiden vaikutuksia puheen havaitsemiseen on tutkttu laajalti, mutta havaitsemiseen liittyvÀt aivomekanismit tunnetaan edelleen melko puutteelisesti etenkin tilanteissa, joissa itse puhesignaali on laadultaan heikentynyt. TÀmÀn vÀitöskirjan tavoitteena oli tutkia puheen havaitsemisen aivomekanismeja tilanteissa, joissa puhesignaali on vaikeammin ymmÀrrettÀvissÀ joko ulkoisen ÀÀnilÀhteen tai digitaalisen pakkauksen vuoksi. VÀitöskirjan neljÀssÀ osatutkimuksessa lyhyiden puheÀÀnien ja jatkuvan puheen ymmÀrrettÀvyyttÀ muokattiin joko digitaalisen pakkauksen kautta tai lisÀÀmÀllÀ puhesignaaliin satunnaiskohinaa. PuheÀrsykkeisiin liittyvÀÀ aivotoimintaa tutkittiin magnetoenkefalografia-mittauksilla. Tutkimuksissa havaittiin, ettÀ kuuloaivokuorella syntyneet herÀtevasteet voimistuivat, kun puheÀÀntÀ pakattiin digitaalisesti. Sen sijaan puheÀÀniin lisÀtty satunnaiskohina ei vaikuttanut herÀtevasteisiin. Edelleen, mikÀli puheÀÀnien taustalla esitettiin jatkuvaa hÀiriötÀ, kuuloaivokuoren aktivoituminen viivÀstyi hÀiriön intensiteetin kasvaessa. Kuuntelukokeissa havaittiin, ettÀ digitaalinen pakkaus heikentÀÀ puheÀÀnien ymmÀrrettÀvyyttÀ voimakkaammin kuin satunnaiskohina. LisÀksi osoitettiin, ettÀ aiempi tieto puheen sisÀllöstÀ paransi merkittÀvÀsti hÀiriöisen puheen ymmÀrrettÀvyyttÀ, mikÀ heijastui aivotoimintaan kuuloaivokuoren viereisillÀ aivoalueilla siten, ettÀ ymmÀrrettÀvÀ puhe aiheutti suuremman aktivaation kuin heikosti ymmÀrrettÀvÀ puhe. VÀitöskirjan tulokset osoittavat, ettÀ kuuloaivokuori on erittÀin herkkÀ puheÀÀnien akustisille hÀiriöille, ja myöhemmissÀ prosessoinnin vaiheissa useat kuuloaivokuoren viereiset aivoalueet heijastavat puheen ymmÀrrettÀvyyttÀ. Tulosten mukaan voi olettaa, ettÀ kuulojÀrjestelmÀ mukautuu nopeasti ÀÀniympÀristön vaihteluihin muun muassa hyödyntÀmÀllÀ aiempaa tietoa puheen sisÀllöstÀ tulkitessaan hÀiriöistÀ puhesignaalia

    Teaching precision farming and entrepreneurship for European students: Sparkle online course

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    Within the framework of the European project named ‘SPARKLE’, an online course was created after studying educational needs on precision agriculture (PA), state of the art of technologies and a prospective study of the commercial sector. Five educational and research institutions, high-tech farms and enterprises specializing in technology transfer created the syllabus of the course and the platform contents. The course was designed to provide 30 h of student dedication, via online presentations, documents and videos for each topic. A free pilot course started in April 2020 and 385 students from Italy, Portugal, Greece & Spain enrolled. To trace performance and acquisition of competences, questionnaires were completed by students for each topic and a final overall test. Students’ opinions about the course were also registered using anonymous polls, and results evaluated, to be able to enhance the Sparkle course for subsequent editions. Students also took part in a business model competition, to solve real challenges proposed by farms, related to the use of these technologies
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