Improving activity recognition using a wearable barometric pressure sensor in mobility-impaired stroke patients.

© 2015 Massé et al.Background: Stroke survivors often suffer from mobility deficits. Current clinical evaluation methods, including questionnaires and motor function tests, cannot provide an objective measure of the patients mobility in daily life. Physical activity performance in daily-life can be assessed using unobtrusive monitoring, for example with a single sensor module fixed on the trunk. Existing approaches based on inertial sensors have limited performance, particularly in detecting transitions between different activities and postures, due to the inherent inter-patient variability of kinematic patterns. To overcome these limitations, one possibility is to use additional information from a barometric pressure (BP) sensor. Methods: Our study aims at integrating BP and inertial sensor data into an activity classifier in order to improve the activity (sitting, standing, walking, lying) recognition and the corresponding body elevation (during climbing stairs or when taking an elevator). Taking into account the trunk elevation changes during postural transitions (sit-to-stand, stand-to-sit), we devised an event-driven activity classifier based on fuzzy-logic. Data were acquired from 12 stroke patients with impaired mobility, using a trunk-worn inertial and BP sensor. Events, including walking and lying periods and potential postural transitions, were first extracted. These events were then fed into a double-stage hierarchical Fuzzy Inference System (H-FIS). The first stage processed the events to infer activities and the second stage improved activity recognition by applying behavioral constraints. Finally, the body elevation was estimated using a pattern-enhancing algorithm applied on BP. The patients were videotaped for reference. The performance of the algorithm was estimated using the Correct Classification Rate (CCR) and F-score. The BP-based classification approach was benchmarked against a previously-published fuzzy-logic classifier (FIS-IMU) and a conventional epoch-based classifier (EPOCH). Results: The algorithm performance for posture/activity detection, in terms of CCR was 90.4 %, with 3.3 % and 5.6 % improvements against FIS-IMU and EPOCH, respectively. The proposed classifier essentially benefits from a better recognition of standing activity (70.3 % versus 61.5 % [FIS-IMU] and 42.5 % [EPOCH]) with 98.2 % CCR for body elevation estimation. Conclusion: The monitoring and recognition of daily activities in mobility-impaired stoke patients can be significantly improved using a trunk-fixed sensor that integrates BP, inertial sensors, and an event-based activity classifier

Morphological Abnormalities in Vitamin B6 Deficient Tarsometatarsal Chick Cartilage

The aim of this study was to test the hypothesis that deficiency of vitamin B6 would produce morphological characteristics of osteochondral lathyrism. To accomplish this goal, morphological characteristics of chick cartilage in which lathyrism was produced by two separate dietary regimens was compared to morphological changes encountered in vitamin B6 deficiency. Vitamin B6 deficiency should reduce activity of lysyloxidase needed for producing intermolecular cross-links. The question to be addressed was: would this latter deficiency impair collagen morphological features and secondarily other structures indirectly by reducing collagen molecular assembly? Failure of cross-linking of collagen in the positive controls was related to a lack of functional aldehyde cross-link intermediates which are blocked by homocysteine and aminoacetonitrile. Day-old-male Lohmann chicks were fed adequate (6 mg/kg) or vitamin B6-deficient diets. Cross-link defects were induced by homocysteine-rich diets (0.6% w/w) or a diet containing aminoacetonitrile (0.1% w/w). Animals were sacrificed at 6 weeks of age and Ossa tarsalia articular cartilage specimens, as well as the proximal end of tarsometatarsus were dissected from the tibial metatarsal joint, a major weight-bearing site. Light microscopic observations revealed reduction of subarticular trabecular bone formation, concurrent with overexpansion of the hypertrophic cell zone. Ultrastructural electron microscopy observations of articular fibro-cartilage indicated significant thickening of collagen fibers in vitamin B6 deficient birds, as well as the positive controls in comparison to that of cage-matched control birds. It was concluded that vitamin B6 deficient cross-linking may be responsible for the observed delay in bone development and aforementioned cartilage histological alterations

REST APIs: A large-scale analysis of compliance with principles and best practices

Quickly and dominantly, REST APIs have spread over the Web and percolated into modern software development practice, especially in the Mobile Internet where they conveniently enable offloading data and computations onto cloud services. We analyze more than 78GB of HTTP traffic collected by Italy’s biggest Mobile Internet provider over one full day and study how big the trend is in practice, how it changed the traffic that is generated by applications, and how REST APIs are implemented in practice. The analysis provides insight into the compliance of state-of-the-art APIs with theoretical Web engineering principles and guidelines, knowledge that affects how applications should be developed to be scalable and robust. The perspective is that of the Mobile Internet

Parent-Child Interaction Therapy for Children With Disruptive Behaviors and Autism: A Randomized Clinical Trial

A relatively large number of children with autism spectrum disorder (ASD) exhibit disruptive behavioral problems. While accumulating data have shown behavioral parent training programs to be efficacious in reducing disruptive behaviors for this population, there is a dearth of literature examining the impact of such programs across the range of ASD severity. To evaluate the effectiveness of Parent–Child Interaction Therapy (PCIT), an evidence-based treatment for children with problem behaviors and their families, in reducing disruptive behaviors among children (4–10 years) with ASD (without intellectual disabilities). Fifty-five children (85.5% male, 7.15 years; SD 1.72) were enrolled from pediatric offices and educational settings into a randomized clinical trial (PCIT: N = 30; Control: N = 25). PCIT families demonstrated a significant reduction in child disruptive behaviors, increase in positive parent–child communication, improvement in child compliance, and reduction in parental stress compared to the control group. Exploratory analyses revealed no differential treatment response based on ASD severity, receptive language, and age. Results are promising for the use of PCIT with children demonstrating disruptive behaviors across the autism spectrum