A Velostat-Based Pressure-Sensitive Mat for Center-of-Pressure Measurements: A Preliminary Study.

Center-of-pressure (CoP) displacements play a key role in studies assessing postural stability. The accepted instrument to measure CoP trajectories is the force platform, but pressure-sensitive mats (PSMs) are an alternative composed of a matrix of sensitive cells. A typical cell comprises two electrodes with piezoresistive material in between, while a force platform has a force sensor at each of its corners. In this paper, we compare a homemade Velostat-based PSM and an affordable commercial mat with a commercial force platform in a test series with 42 healthy volunteers in single-legged trials (29 males, 13 females; height 1.74 (0.09) m, weight 74.3 (16.34) kg, age 31.21 (12.66) years). The aim of the research was to perform a preliminary study of the performance of our prototype to measure CoP, and more specifically, the standard deviation of the CoP path on both axes, the medial-lateral and anterior-posterior. We could thus discover several improvements for future clinical applications. The intraclass correlation coefficient (ICC) for agreement in the base experiment showed a moderate value for the prototype (0.38 to 0.63) and lower values for the commercial mat (0.11 to 0.12). However, we identified several factors that were relevant to improve ICC and reduce error by considering several processing options: (i) the known crosstalk problem between cells that appears in this kind of mats must be eliminated; (ii) the response time of the sensor has to be taken into account; and (iii) increasing the mat resolution also improves agreement. Therefore, as future work, we plan to test the improved version of the prototype in a clinical environment.

Development and initial evaluation of a mobile application to help with mindfulness training and practice.

BACKGROUND AND OBJECTIVE: Different review articles support the usefulness and effectiveness of mindfulness techniques in health and wellbeing. In this paper we present a first prototype of a mobile application to help with the training and practice of mindfulness, taking into account the lacks detected in a previous literature review. Our aim was to measure acceptance and perceived quality, as well as gather data about app usage. Their dependence on demographic variables and the change in mindful level was also measured. MATERIALS AND METHODS: Two versions of a new application were developed, "Mindfulness" and "Mindfulness Sci". The application has been tested in two pilot studies: in traditional face-to-face mindfulness groups and in individual and independent use. RESULTS: 3977 users were involved in this study: 26 in the first trial during an 8-week usage period and 3951 in the second trial during 17 months. In the first study, participants assessed the app with high scores. They considered it as a helping tool for mindfulness practice, user-friendly and with high quality of use. The positive perception was maintained after 8-weeks meditation workshops, and participants considered that its use could contribute to obtain benefits for mental and physical health. In the second study, we found rather weak associations between usage time and age, nationality and educational level. The mindful level showed a weak positive correlation with the session accomplished but slightly above the boundary of statistical significance (p-value=0.051). Videos and information stood out as the most accessed resources. CONCLUSIONS: Up to our knowledge, this is the first app developed with the help of health professionals in Spanish that could be used with a general aim, in health and wellbeing. The results are promising with a positive evaluation in face-to-face and independent use situations. Therefore, the number of potential users is enormous in a global worldwide context.