1,720,983 research outputs found

    Learning to Control Brain Activity: a Review of the Production and Control of EEG Components for Driving Brain-computer interface (BCI) systems

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    Brain–computer interface (BCI) technology relies on the ability of individuals to voluntarily and reliably produce changes in their electroencephalographic (EEG) activity. The present paper reviews research on cognitive tasks and other methods of generating and controlling specific changes in EEG activity that can be used to drive BCI systems. To date, motor imagery has been the most commonly used task. This paper explores the possibility that other cognitive tasks, including those used in imaging studies, may prove to be more effective. Other factors which influence performance are also considered in relation to selection of tasks, as well as training of subjects

    Segmenting Mechanomyography Measures of Muscle Activity Phases Using Inertial Data

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    This dataset contains the data used in our manuscript titled &quot;Segmenting Mechanomyography Measures of Muscle Activity Phases Using Inertial Data&quot;. Data structure is explained in the README.txt file located at the top-level of the dataset. Manuscript title in the README.txt file and contained in the title of the zip file are of a previous working title. Please contact corresponding author Richard B. Woodward for any questions.</span

    Comparison of curvilinear and linear ultrasound imaging probes for measuring cross-sectional area and linear dimensions

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    The aim of the study was to determine whether different ultrasound probe/transducer configurations produce the same measurements. Two investigators undertook 10 scans of a general purpose semi-solid multi-tissue ultrasound phantom (phantom A) using two ultrasound scanners with a linear and curvilinear probe. From those 10 scans, two measurements of cross-sectional area (CSA), width and thickness were made. These measurements were then repeated with an open-top fluid-filled phantom, with 10% ethanol solution (phantom B). Intra- and inter-rater reliability were examined using Bland and Altman plots. Agreement between measurements made with the two probe types was also assessed using Bland and Altman plots. An independent samples t-test was used to compare statistical differences between probe type configuration. There was a significant difference (p &lt; 0.05) and a tendency for increased measurements in CSA and width, and decreased measurements in thickness when using a curvilinear probe on phantom A, and these differences were not scanner specific. When imaging phantom B there were no significant differences in measurements between probe configurations; however there was a small bias for smaller CSA measurements with a curvilinear probe. In conclusion there are small differences in measurements obtained from different ultrasound probe configurations using a semi-solid phantom, but their clinical significance is unknown

    Ultrasound imaging and muscle function

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    There is a growing trend in the physical therapy profession to use conventional gray scale brightness (B) mode ultrasound imaging (USI) as a tool to assess the morphological (form and structure) and morphometric (measures of form) characteristics of muscle and then using these findings to draw conclusions regarding muscle function. This trend is reflected in numerous investigations published in the physical therapy literature. As physical therapists typically lack training in the principles and instrumentation underlying USI use it is critical that therapists gain a clear understanding of the information that USI can, and cannot, provide about muscle function, before employing the technique for either research or clinical applications. Failure to do so may result in the propagation of inaccurate terminology and beliefs. This paper aims to clarify the role that USI has in the assessment of muscle function, firstly by briefly reviewing how conventional grey scale B-mode ultrasound images and clips are generated, and secondly by summarizing the types of information that these images can provide. It will then go on to discuss the various factors that need to be considered when interpreting a dynamic USI assessment of muscle, specifically as it relates to the assessment of muscle function

    Validity of ultrasound imaging versus magnetic resonance imaging for measuring anterior thigh muscle, subcutaneous fat, and fascia thickness

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    The aim of the present study was to determine the validity of ultrasound (US) imaging versus magnetic resonance imaging (MRI) for measuring anterior thigh muscle, subcutaneous adipose tissue (SAT), and fascia thickness. Twenty healthy, moderately active participants (aged 49.1 ± 9.74 (36–64) years), underwent imaging of the anterior thigh, using ultrasound and MRI modalities on the same day. Images were analyzed offline to assess the level of agreement between US and MRI measurements. Pearson’s correlation coefficient showed an excellent relationship between US imaging and MRI for measuring muscle (r = 0.99, p &lt; 0.01), SAT (r = 0.99, p &lt; 0.01), and non-contractile tissue (SAT combined with perimuscular fascia) thickness (r = 0.99, p &lt; 0.01). Perimuscular fascia thickness measurement showed a poor correlation between modalities (r = 0.39, p &lt; 0.01). Intra-class correlation coefficients (ICC3,1) also showed excellent correlation of the measurements with ICC = 0.99 for muscle thickness, SAT, and non-contractile tissue, but not for perimuscular fascia, which showed poor agreement ICC = 0.36. Bland and Altman plots demonstrated excellent agreement between US imaging and MRI measurements. Criterion validity was demonstrated for US imaging against MRI, for measuring thickness of muscle and SAT, but not perimuscular fascia alone on the anterior thigh. The US imaging technique is therefore applicable for research and clinical purposes for muscle and SAT

    Measuring scapular kinematics during arm lowering using the acromion marker cluster

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    The aim of the present study was to examine the acromion marker cluster (AMC) method of measuring scapular kinematics during the arm lowering, eccentric, phase. Twenty six participants completed arm elevation and lowering in the sagittal, frontal and scapular plane. The participants held their arm at 30° increments while the orientation of the scapula was recorded using an AMC and a scapular locator (SL). There were no significant differences between the AMC and SL during the lowering phase for sagittal and scapular plane arm movements. The AMC significantly underestimated upward rotation (max RMSE = 6.0°), and significantly overestimated posterior tilt (max RMSE = 7.2°) during arm lowering in the frontal plane. The reported root mean square errors, however, were within the ranges observed during the elevation phase and reported in previous literature. The AMC therefore provides a reasonable description of scapular kinematics during the arm lowering phase

    Postpartum characteristics of rectus abdominis on ultrasound imaging

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    This cross-sectional and partial longitudinal study aimed to characterize changes in rectus abdominis (RA) and provide reference ranges for the first year postpartum. Ultrasound scanning was used at four stages postnatally to measure cross-sectional area (CSA), thickness, width (indirectly using a shape value) and inter-recti distance (IRD). One hundred and fifteen postnatal women (though some postnatal subjects appeared in more than one postnatal group thus giving a total of 183 data points) and 69 age-matched nulliparous female controls were recruited. Postnatal subjects were studied at Day 1 (PN1; n=63) and at 2 (PN2; n=55), 6 (PN3; n=39) and 12 (PN4; n=26) months postpartum. Longitudinal data were analysed for CSA, thickness, shape (indirect width measurement) (df=67) and IRD (df=62). The mean CSA of the PN1 group was significantly larger (P&lt;0.001) than in controls and decreased (P&lt;0.0021) by 12 months. In all postnatal groups, RA was significantly thinner (P&lt;0.0001, PN1–PN3; P&lt;0.0478, PN4), wider (P&lt;0.0001, PN1–PN3; P=0.0326, PN4) and the IRD was significantly larger (P&lt;0.0001, PN1–PN4) than in controls. Over 2 months postpartum, RA became thicker (P=0.0003) and the width and IRD decreased (P&lt;0.0001 and P=0.0002, respectively) but did not return to control values by 12 months. These results have implications for strength of RA postpartum and anterior abdominal wall stiffness, which together with other muscle characteristics could inform development of effective postnatal exercise programmes
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