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https://www.readbyqxmd.com/read/28814064/electrical-properties-assessed-by-bioelectrical-impedance-spectroscopy-as-biomarkers-of-age-related-loss-of-skeletal-muscle-quantity-and-quality
#1
Yosuke Yamada, Bjoern Buehring, Diane Krueger, Rozalyn M Anderson, Dale A Schoeller, Neil Binkley
Skeletal muscle, in addition to being comprised of a heterogeneous muscle fiber population, also includes extracellular components that do not contribute to positive tensional force production. Here we test segmental bioelectrical impedance spectroscopy (S-BIS) to assess muscle intracellular mass and composition. S-BIS can evaluate electrical properties that may be related to muscle force production. Muscle fiber membranes separate the intracellular components from the extracellular environment and consist of lipid bilayers which act as an electrical capacitor...
September 1, 2017: Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
https://www.readbyqxmd.com/read/28814050/segmental-contributions-to-sagittal-plane-whole-body-angular-momentum-when-using-powered-compared-to-passive-ankle-foot-prostheses-on-ramps
#2
Nathaniel T Pickle, Anne K Silverman, Jason M Wilken, Nicholas P Fey
Understanding the effects of an assistive device on dynamic balance is crucial, particularly for robotic leg prostheses. Analyses of dynamic balance commonly evaluate the range of whole-body angular momentum (H). However, the contributions of individual body segments to overall H throughout gait may yield futher insights, specifically for people with transtibial amputation using powered prostheses. We evaluated segment contributions to H using Statistical Parametric Mapping to assess the effects of prosthesis type (powered vs passive) and ramp angle on segmental coordination...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28814047/a-simple-tool-to-measure-spasticity-in-spinal-cord-injury-subjects
#3
Arash Arami, Nevio L Tagliamonte, Federica Tamburella, Hsieng-Yung Huang, Marco Molinari, Etienne Burdet
This work presents a wearable device and the algorithms for quantitative modelling of joint spasticity and its application in a pilot group of subjects with different levels of spinal cord injury. The device comprises light-weight instrumented handles to measure the interaction force between the subject and the physical therapist performing the tests, EMG sensors and inertial measurement units to measure muscle activity and joint kinematics. Experimental tests included the passive movement of different body segments, where the spasticity was expected, at different velocities...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28814000/preliminary-study-of-a-robotic-foot-ankle-prosthesis-with-active-alignment
#4
Andrew K LaPre, Ryan D Wedge, Brian R Umberger, Frank C Sup
Robotic prosthetic foot-ankle prostheses typically aim to replace the lost joint with revolute joints aimed at replicating normal joint biomechanics. In this paper, a previously developed robotic ankle prosthesis with active alignment is evaluated. It uses a four-bar mechanism to inject positive power into the gait cycle while altering the kinematics of the ankle joint and pylon segment to reduce loading on the residual limb. In a single-subject biomechanics analysis, there was a 10% reduction in peak limb pressures and evidence of greater gait symmetry in ground reaction forces when active alignment was implemented compared to walking with the daily use prosthesis...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813999/upper-limb-prosthetic-control-using-wearable-multichannel-mechanomyography
#5
Samuel Wilson, Ravi Vaidyanathan
In this paper we introduce a robust multi-channel wearable sensor system for capturing user intent to control robotic hands. The interface is based on a fusion of inertial measurement and mechanomyography (MMG), which measures the vibrations of muscle fibres during motion. MMG is immune to issues such as sweat, skin impedance, and the need for a reference signal that is common to electromyography (EMG). The main contributions of this work are: 1) the hardware design of a fused inertial and MMG measurement system that can be worn on the arm, 2) a unified algorithm for detection, segmentation, and classification of muscle movement corresponding to hand gestures, and 3) experiments demonstrating the real-time control of a commercial prosthetic hand (Bebionic Version 2)...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813996/analyzing-at-home-prosthesis-use-in-unilateral-upper-limb-amputees-to-inform-treatment-device-design
#6
Adam J Spiers, Linda Resnik, Aaron M Dollar
New upper limb prosthetic devices are continuously being developed by a variety of industrial, academic, and hobbyist groups. Yet, little research has evaluated the long term use of currently available prostheses in daily life activities, beyond laboratory or survey studies. We seek to objectively measure how experienced unilateral upper limb prosthesis-users employ their prosthetic devices and unaffected limb for manipulation during everyday activities. In particular, our goal is to create a method for evaluating all types of amputee manipulation, including non-prehensile actions beyond conventional grasp functions, as well as to examine the relative use of both limbs in unilateral and bilateral cases...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813994/two-single-cases-treated-by-a-new-pseudoelastic-upper-limb-orthosis-for-secondary-dystonia-of-the-young
#7
Lorenzo Garavaglia, Emanuela Pagliano, Maria Teresa Arnoldi, Antonella LoMauro, Riccardo Zanin, Giovanni Baranello, Andrea Aliverti, Simone Pittaccio
The study proposes a new treatment for dystonia based on a dynamic wearable orthosis equipped with metallic materials of non-linear mechanical characteristics. Two boys with upper-limb dystonia were enrolled, as well as six healthy children. Fully-customised devices were made for the patients. They used the orthosis for one month and their performances were evaluated before and after the treatment. The assessment was done with clinical scales (Modified Ashworth Score, Melbourne Upper Limb Assessment, PedsQL), interviews and optoelectronic kinematic analysis...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813947/exploiting-kinematic-constraints-to-compensate-magnetic-disturbances-when-calculating-joint-angles-of-approximate-hinge-joints-from-orientation-estimates-of-inertial-sensors
#8
Daniel Laidig, Thomas Schauer, Thomas Seel
Inertial Measurement Units (IMUs) have become a widely used tool for rehabilitation and other application domains in which human motion is analyzed using an ambulatory or wearable setup. Since the magnetic field is inhomogeneous in indoor environments and in the proximity of ferromagnetic material, standard orientation estimation and joint angle calculation algorithms often lead to inaccurate or even completely wrong results. One approach to circumvent this is to exploit the kinematic constraint that is induced by mechanical hinge joints and also by approximate hinge joints such as the knee joint and the finger (interphalangeal) joints of the human body...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813877/capture-learning-and-classification-of-upper-extremity-movement-primitives-in-healthy-controls-and-stroke-patients
#9
Jorge Guerra, Jasim Uddin, Dawn Nilsen, James Mclnerney, Ammarah Fadoo, Isirame B Omofuma, Shatif Hughes, Sunil Agrawal, Peter Allen, Heidi M Schambra
There currently exist no practical tools to identify functional movements in the upper extremities (UEs). This absence has limited the precise therapeutic dosing of patients recovering from stroke. In this proof-of-principle study, we aimed to develop an accurate approach for classifying UE functional movement primitives, which comprise functional movements. Data were generated from inertial measurement units (IMUs) placed on upper body segments of older healthy individuals and chronic stroke patients. Subjects performed activities commonly trained during rehabilitation after stroke...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813858/active-impedance-control-of-a-knee-joint-orthosis-during-swing-phase
#10
Fatima El Zahraa Wehbi, Weiguang Huo, Yacine Amirat, Maher El Rafei, Mohamad Khalil, Samer Mohammed
In this paper, an active impedance control strategy for a knee-joint orthosis is proposed to assist individuals suffering from lower-limb muscular weaknesses during the swing phase of walking activities. The goal of the proposed strategy is to decrease the human effort required for ensuring a successful knee joint movement during walking without sacrificing the wearer's control priority. In this study, a gait-phase based desired knee-joint admittance model is designed by analyzing the kinematic and kinetic characteristics of the wearer's shank-foot segment during walking...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813847/a-research-on-the-postural-stability-of-a-person-wearing-the-lower-limb-exoskeletal-robot-by-the-hat-model
#11
Minsu Chang, Yeongmin Kim, Yoseph Lee, Doyoung Jeon
This paper proposes a method of detecting the postural stability of a person wearing the lower limb exoskeletal robot with the HAT(Head-Arm-Trunk) model. Previous studies have shown that the human posture is stable when the CoM(Center of Mass) of the human body is placed on the BoS(Base of Support). In the case of the lower limb exoskeletal robot, the motion data, which are used for the CoM estimation, are acquired by sensors in the robot. The upper body, however, does not have sensors in each segment so that it may cause the error of the CoM estimation...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813753/pre-guideline-trends-associated-with-chest-radiograph-usage-for-pediatric-community-acquired-pneumonia-in-emergency-department-settings
#12
Eric W Jones, Benjamin Meyer, Aaron M Berg, Benson S Hsu
BACKGROUND: Health care spending in the U.S. totaled $3 trillion in 2014 and continues to increase rapidly. Minimizing waste through clinical guidelines is a promising strategy to reduce spending without compromising patient care. In 2011, clinical guidelines recommended against the use of chest X-ray (CXR) for diagnosis of community-acquired pneumonia (CAP) in pediatric ambulatory settings. However, use of CXR has not changed post-guideline. Thus, understanding the drivers of CXR utilization prior to guideline implementation could improve guideline adherence...
May 2017: South Dakota Medicine: the Journal of the South Dakota State Medical Association
https://www.readbyqxmd.com/read/28813577/spatial-correspondence-between-intraretinal-fluid-subretinal-fluid-and-pigment-epithelial-detachment-in-neovascular-age-related-macular-degeneration
#13
Sophie Klimscha, Sebastian M Waldstein, Thomas Schlegl, Hrvoje Bogunovic, Amir Sadeghipour, Ana-Maria Philip, Dominika Podkowinski, Eleonore Pablik, Li Zhang, Michael D Abramoff, Milan Sonka, Bianca S Gerendas, Ursula Schmidt-Erfurth
Purpose: To identify the spatial distribution of exudative features of choroidal neovascularization in neovascular age-related macular degeneration (nAMD) based on the localization of intraretinal cystoid fluid (IRC), subretinal fluid (SRF), and pigment-epithelial detachment (PED). Methods: This retrospective cross-sectional study included spectral-domain optical coherence tomography volume scans (6 × 6 mm) of 1341 patients with treatment-naïve nAMD. IRC, SRF, and PED were detected on a per-voxel basis using fully automated segmentation algorithms...
August 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28813472/an-intronic-line-1-insertion-in-mertk-is-strongly-associated-with-retinopathy-in-swedish-vallhund-dogs
#14
Richard Everson, Louise Pettitt, Oliver P Forman, Olivia Dower-Tylee, Bryan McLaughlin, Saija Ahonen, Maria Kaukonen, András M Komáromy, Hannes Lohi, Cathryn S Mellersh, Jane Sansom, Sally L Ricketts
The domestic dog segregates a significant number of inherited progressive retinal diseases, several of which mirror human retinal diseases and which are collectively termed progressive retinal atrophy (PRA). In 2014, a novel form of PRA was reported in the Swedish Vallhund breed, and the disease was mapped to canine chromosome 17. The causal mutation was not identified, but expression analyses of the retinas of affected Vallhunds demonstrated a 6-fold increased expression of the MERTK gene compared to unaffected dogs...
2017: PloS One
https://www.readbyqxmd.com/read/28813459/%C3%AE-2-microglobulin-gene-duplication-in-cetartiodactyla-remains-intact-only-in-pigs-and-possibly-confers-selective-advantage-to-the-species
#15
Thong Minh Le, Quy Van Chanh Le, Dung Minh Truong, Hye-Jeong Lee, Min-Kyeung Choi, Hyesun Cho, Hak-Jae Chung, Jin-Hoi Kim, Jeong-Tae Do, Hyuk Song, Chankyu Park
Several β2-microglobulin (B2M) -bound protein complexes undertake key roles in various immune system pathways, including the neonatal Fc receptor (FcRn), cluster of differentiation 1 (CD1) protein, non-classical major histocompatibility complex (MHC), and well-known MHC class I molecules. Therefore, the duplication of B2M may lead to an increase in the biological competence of organisms to the environment. Based on the pig genome assembly SSC10.2, a segmental duplication of ~45.5 kb, encoding the entire B2M protein, was identified in pig chromosome 1...
2017: PloS One
https://www.readbyqxmd.com/read/28813418/mechanism-of-intracellular-allosteric-%C3%AE-2ar-antagonist-revealed-by-x-ray-crystal-structure
#16
Xiangyu Liu, Seungkirl Ahn, Alem W Kahsai, Kai-Cheng Meng, Naomi R Latorraca, Biswaranjan Pani, A J Venkatakrishnan, Ali Masoudi, William I Weis, Ron O Dror, Xin Chen, Robert J Lefkowitz, Brian K Kobilka
G-protein-coupled receptors (GPCRs) pose challenges for drug discovery efforts because of the high degree of structural homology in the orthosteric pocket, particularly for GPCRs within a single subfamily, such as the nine adrenergic receptors. Allosteric ligands may bind to less-conserved regions of these receptors and therefore are more likely to be selective. Unlike orthosteric ligands, which tonically activate or inhibit signalling, allosteric ligands modulate physiologic responses to hormones and neurotransmitters, and may therefore have fewer adverse effects...
August 16, 2017: Nature
https://www.readbyqxmd.com/read/28813195/prediction-of-therapeutic-response-of-hepatocellular-carcinoma-to-transcatheter-arterial-chemoembolization-based-on-pretherapeutic-dynamic-ct-and-textural-findings
#17
Hyun Jeong Park, Jung Hoon Kim, Seo-Youn Choi, Eun Sun Lee, Sang Joon Park, Jae Young Byun, Byung Ihn Choi
OBJECTIVE: The objective of our study was to assess the value of CT texture analysis for prediction of therapeutic response of hepatocellular carcinoma (HCC) to transcatheter arterial chemoembolization (TACE) with pretherapeutic dynamic CT. MATERIALS AND METHODS: We retrospectively analyzed 132 HCCs in 96 patients treated with TACE who underwent dynamic CT before initial TACE. Imaging findings and arterial enhancement ratios were analyzed. All HCCs were manually segmented, and their texture features were quantitatively extracted using in-house software...
August 16, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28813084/bereitschaftspotential-preceding-eyelid-blinks-in-parkinson-s-disease
#18
Isabella Araújo Mota, Maria das Graças Coriolano, Otávio Gomes Lins
Methods: Ten PD patients in stages 1 and 2 of the Hoehn & Yahr classification were compared to 18 healthy controls. Artifact-free EEG segments of two seconds preceding the onset of the blink potential were averaged and analyzed, and the statistical significance of the measured amplitudes were evaluated by analysis of variance models. Results: The presence of a BP in the PD patients was demonstrated. The mean amplitudes at 0 ms were respectively 0.6 µV and 3.3 µV for the BP patients and the normal controls, respectively...
August 2017: Arquivos de Neuro-psiquiatria
https://www.readbyqxmd.com/read/28812976/learning-and-recognition-of-tactile-temporal-sequences-by-mice-and-humans
#19
Michael R Bale, Malamati Bitzidou, Anna Pitas, Leonie S Brebner, Lina Khazim, Stavros T Anagnou, Caitlin D Stevenson, Miguel Maravall
The world around us is replete with stimuli that unfold over time. When we hear an auditory stream like music or speech or scan a texture with our fingertip, physical features in the stimulus are concatenated in a particular order. This temporal patterning is critical to interpreting the stimulus. To explore the capacity of mice and humans to learn tactile sequences, we developed a task in which subjects had to recognise a continuous modulated noise sequence delivered to whiskers or fingertips, defined by its temporal patterning over hundreds of milliseconds...
August 16, 2017: ELife
https://www.readbyqxmd.com/read/28812736/the-evolution-and-population-diversity-of-human-specific-segmental-duplications
#20
Megan Y Dennis, Lana Harshman, Bradley J Nelson, Osnat Penn, Stuart Cantsilieris, John Huddleston, Francesca Antonacci, Kelsi Penewit, Laura Denman, Archana Raja, Carl Baker, Kenneth Mark, Maika Malig, Nicolette Janke, Claudia Espinoza, Holly A F Stessman, Xander Nuttle, Kendra Hoekzema, Tina A Lindsay-Graves, Richard K Wilson, Evan E Eichler
Segmental duplications contribute to human evolution, adaptation and genomic instability but are often poorly characterized. We investigate the evolution, genetic variation and coding potential of human-specific segmental duplications (HSDs). We identify 218 HSDs based on analysis of 322 deeply sequenced archaic and contemporary hominid genomes. We sequence 550 human and nonhuman primate genomic clones to reconstruct the evolution of the largest, most complex regions with protein-coding potential (N = 80 genes from 33 gene families)...
February 17, 2017: Nature ecology & evolution
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