Improving accessibility of tactile interaction for older users: lowering accuracy requirements to support drag-and-drop interaction

International audienceMobile applications offer great possibilities to the aging population but older adults face accessibility problems when using devices equipped with touchscreen. In order to respond to older users' special needs, it is necessary to support older users during tactile interaction to reduce error rates. The aim of this study is to evaluate the effects of the accuracy requirements for drag-and-drop interaction. 24 able-bodied older adults with different profiles (aged 65 to 86 years old, with corrected and not corrected eyesight, normal and low dexterity, different levels of education, different experience of use of computers and touchscreen) executed a series of tactile puzzle games on smartphone and tablet, with pen and fingers. We evaluate the number of errors for two levels of accuracy required for positioning the puzzle pieces: 95% (higher) and 80% (lower). Older adults made fewer errors of accuracy during lower accuracy levels and consequently fewer supplementary gestures for positioning the targets. Besides, lowering the accuracy requirement was an effective support for interaction because it also reduced the effects of users' profiles, improving the accessibility for people with no experience of use of computers

Ease-of-Use of Tactile Interaction for Novice Older Adults

International audienceUsability, particularly ease-of-use, is a main factor affecting the acceptance of technologies by older adults. Mobile devices offer great possibilities for well-being applications, but they are often equipped with touchscreen. In order to evaluate the ease-of-use of tactile interaction, this study compares the performances of 16 novice (mean age 74) and 8 experienced older adults (mean 75) during the execution of drag-and-drop interaction for achieving tactile puzzle games on smartphone and tablet, with pen and fingers. Results show that novice users were able accomplish interaction accurately with longer times but no significant difference of errors of accuracy

Etude comparative de l'analyse des mouvements lors d'une interaction tactile : adultes versus ainés

International audienceThis paper reports a comparative study on the analysis of the users’ movements and their consequences in users’ performances (time, error rates) during interaction of 15 older adults and 15 adults with touchscreen. The analysis of the movement of the users’ wrist during the execution of interaction gestures allow to understand the differences in performances between older and younger users.Cet article présente une étude comparative de l'analyse des mouvements de l'utilisateur et leurs conséquences sur la performance (temps, taux d'erreurs) durant l'interaction avec des écrans tactiles sur une population de 15 participants âgés versus 15 adultes. L'analyse du mouvement du poignet durant l'exécution des gestes d'interaction permet de comprendre les différences de performances entre utilisateurs âgés et plus jeunes

Interaction techniques for older adults using touchscreen devices : a literature review

International audienceSeveral studies investigated different interaction techniques and input devices for older adults using touchscreen. This literature review analyses the population involved, the kind of tasks that were executed, the apparatus, the input techniques, the provided feedback, the collected data and author's findings and their recommendations. As conclusion, this review shows that age-related changes, previous experience with technologies, characteristics of handheld devices and use situations need to be studied

Crystallisation and chain conformation of long chain n-alkanes.

Hydrocarbon chains are a basic component in a number of systems as diverse as biological membranes, phospholipids and polymers. A better understanding of the physical properties of n-alkane chains should provide a better understanding of these more complex systems. With this aim, vibrational spectroscopy has been extensively used. This technique, sensitive to molecular details, is the only one able to both identify and quantify conformational disorder present in paraffinic systems. To achieve this, methyl deformations have been widely used as "internal standards" for the normalisation of peak areas. However, in the case of n-alkanes with short chain length, such as n-C[44]H[90] for example, the infrared spectra recorded at liquid nitrogen temperature and reported here show the sensitivity of these latter peaks to the various crystal structures formed. Indeed, the main frequencies of the symmetric methyl bending mode were found between 1384 cm[-1] and 1368 cm[-1] as a function of the crystal form. Changes in the frequency of the first order of the L.A.M. present in the Raman spectra were also observed. At higher temperatures, non all-trans conformers, inferred from different infrared bands present in the wagging mode region, were found to be essentially placed at the end of the n-alkane chains. At the monoclinic phase transition, the concentration of end-gauche conformers, proportional to the area of the infrared band at 1342 cm[-1], increases abruptly. On the contrary, in the spectra recorded at liquid nitrogen temperature no such band is observed. We also studied the degree of disorder in two purely monodisperse long chain n-alkanes, namely n-C[198]H[398] and n-C[246]H[494]. The chain conformation as well as the tilt angle of the chains from the crystal surfaces were determined by means of low frequency Raman spectroscopy and S.A.X.S. measurements on solution-crystallised samples. The increase in the number of end-gauche conformers which was expected to occur with the increase of the tilt angle as a function of the temperature was not detected due to a perfecting of the crystals. Indeed, due to successive heating and cooling to -173°C, the concentration of non all-trans conformers was found to decrease within the crystals. Their numbers were found to be up to six times higher in n-C[198]H[398] crystallised in once folded form than when crystallised in extended form. The C-C stretching mode region of the spectra was used to identify the chain conformation and to estimate the length of the all-trans stem passing through the crystal layers at -173°C. The transition between once folded and extended form crystals was indicated by the presence of additional bands in this region at 1089 cm[-1], 1078 cm[-1] and 1064 cm[-1]. Some of those bands may be related to the fold itself. At the same time, a strong decrease of the intensity of the infrared bands present in the wagging mode region was observed.Finally, the triple layered structure proposed on the basis of X-ray measurements obtained from the crystals of a binary mixture of long chain n-alkanes, namely n-C[162]H[326] and n-C[246]H[494], was confirmed from the study of the C-C stretching mode region of the infrared spectra

Theme E: disabilities: analysis models and tools

International audienceThis paper presents the topics and the activity of the theme E “disabilities: analysis models and tools” within the GDR STIC Santé. This group has organized a conference and a workshop during the period 2011–2012. The conference has focused on technologies for cognitive, sensory and motor impairments, assessment and use study of assistive technologies, user centered method design and the place of ethics in these research topics. The objective of “bodily integration of technique” workshop, organized in the framework of Défi Sens (CNRS) was to develop a multidisciplinary approach (physiology, robotics and anthropology) of the relationships between body and technology taking as an example the prostheses for the compensation of sensorimotor disabilities. Efforts will focus on strengthening the development of a multidisciplinary research for the design of assistive technologies for elderly people and people with disabilities. The modelling of the user’s abilities and the designing of adaptable AT to the needs of the person will be carried out with other groups of this GDR and also with other GDRs

Upper-Limb Isometric Force Feasible Set: Evaluation of Joint Torque-Based Models

International audienceA force capacity evaluation for a given posture may provide better understanding of human motor abilities for applications in sport sciences, rehabilitation and ergonomics. From data on posture and maximum isometric joint torques, the upper-limb force feasible set of the hand was predicted by four models called force ellipsoid, scaled force ellipsoid, force polytope and scaled force polytope, which were compared with a measured force polytope. The volume, shape and force prediction errors were assessed. The scaled ellipsoid underestimated the maximal mean force, and the scaled polytope overestimated it. The scaled force ellipsoid underestimated the volume of the measured force distribution, whereas that of the scaled polytope was not significantly different from the measured distribution but exhibited larger variability. All the models characterized well the elongated shape of the measured force distribution. The angles between the main axes of the modelled ellipsoids and polytopes and that of the measured polytope were compared. The values ranged from 7.3° to 14.3°. Over the entire surface of the force ellipsoid, 39.7% of the points had prediction errors less than 50 N; 33.6% had errors between 50 and 100 N; and 26.8% had errors greater than 100N. For the force polytope, the percentages were 56.2%, 28.3% and 15.4%, respectively

Redundancy Tubes: Modelling Individual and Group Range-of-Motions Along a Path

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Feet and legs tracking using a smart rollator equipped with a Kinect

International audienceClinical evaluation of frailty in the elderly is the first step to decide the degree of assistance they require. Advances in robotics make it possible to turn a standard assistance device into an augmented device that may enrich the existing tests with new sets of daily measured criteria. In this paper we use a standard 4 wheeled rollator, equipped with a Kinect and odometers, for biomechanical gait analysis. This paper focuses on the method we develop to measure and estimate legs and feet position during an assisted walk. The results are compared with motion capture data, as a ground truth. Preliminary results obtained on four healthy persons show that relevant data can be extracted for gait analysis. Some criteria are accurate with regards to the ground truth, eg. foot orientation and ankle angle