scholarly journals Development, validation, and pilot MRI safety study of a high-resolution, open source, whole body pediatric numerical simulation model

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0241682
Author(s):  
Hongbae Jeong ◽  
Georgios Ntolkeras ◽  
Michel Alhilani ◽  
Seyed Reza Atefi ◽  
Lilla Zöllei ◽  
...  
Keyword(s):  
Brain Structures ◽  
International Standards ◽  
Whole Body ◽  
Synthetic Image ◽  
Mri Safety ◽  
Older Children ◽  
Implantable Medical Device ◽  
Tissue Compartments ◽  
International Standards Organization ◽  
Age Range

Numerical body models of children are used for designing medical devices, including but not limited to optical imaging, ultrasound, CT, EEG/MEG, and MRI. These models are used in many clinical and neuroscience research applications, such as radiation safety dosimetric studies and source localization. Although several such adult models have been reported, there are few reports of full-body pediatric models, and those described have several limitations. Some, for example, are either morphed from older children or do not have detailed segmentations. Here, we introduce a 29-month-old male whole-body native numerical model, “MARTIN”, that includes 28 head and 86 body tissue compartments, segmented directly from the high spatial resolution MRI and CT images. An advanced auto-segmentation tool was used for the deep-brain structures, whereas 3D Slicer was used to segment the non-brain structures and to refine the segmentation for all of the tissue compartments. Our MARTIN model was developed and validated using three separate approaches, through an iterative process, as follows. First, the calculated volumes, weights, and dimensions of selected structures were adjusted and confirmed to be within 6% of the literature values for the 2-3-year-old age-range. Second, all structural segmentations were adjusted and confirmed by two experienced, sub-specialty certified neuro-radiologists, also through an interactive process. Third, an additional validation was performed with a Bloch simulator to create synthetic MR image from our MARTIN model and compare the image contrast of the resulting synthetic image with that of the original MRI data; this resulted in a “structural resemblance” index of 0.97. Finally, we used our model to perform pilot MRI safety simulations of an Active Implantable Medical Device (AIMD) using a commercially available software platform (Sim4Life), incorporating the latest International Standards Organization guidelines. This model will be made available on the Athinoula A. Martinos Center for Biomedical Imaging website.

On Using the ISO Standard To Evaluate the Ride Quality of Broad-Band Vibration Spectra in Transportation Vehicles

1976 ◽  
Vol 98 (4) ◽  
pp. 440-443 ◽  
Author(s):  
Craig C. Smith
Keyword(s):  
Broad Band ◽  
International Standards ◽  
Whole Body ◽  
Ride Quality ◽  
Iso Standard ◽  
Vibration Data ◽  
Power Spectral ◽  
Country Road ◽  
International Standards Organization ◽  
Iso 2631

The International Standards Organization “Guide for the Evaluation of Human Exposure to Whole-Body Vibrations”, ISO 2631, is converted to a form usable for direct comparison with vibration data represented in power spectral density form. Comparisons are made between the ISO standard, the Urban Tracked Air Cushion Vehicle (UTACV) specification, and measured vibrations at the floorboard and seat of an automobile over smooth and rough roads. The data indicate that the ISO standard is less restrictive than the UTACV specification, and generally not restrictive enough to indicate the roughness of an automobile ride on a rough country road.

scholarly journals International Standards Organization-Compatible Index for Pavement Roughness

1998 ◽  
Vol 1643 (1) ◽  
pp. 110-115 ◽  
Author(s):  
A. T. Papagiannakis ◽  
B. Raveendran
Keyword(s):  
Unit Length ◽  
International Standards ◽  
Whole Body ◽  
User Cost ◽  
Pavement Roughness ◽  
Power Spectral ◽  
Reference Vehicle ◽  
Roughness Index ◽  
Pavement Damage ◽  
International Standards Organization

The development of a new pavement roughness index, which is compatible to the current International Standards Organization (ISO) standard on “exposure to whole-body vibration” is described. The index was intended to be the independent variable in the future development of relationships between user cost (i.e., vehicle depreciation, repairs, discomfort and so on) and pavement roughness; hence it was named RIDE (Roughness Index for Driving Expenditure). RIDE is based on the sprung mass acceleration response of a reference vehicle to the pavement profile. It is calculated in the frequency domain by multiplying the power spectral density (PSD) of the pavement profile by the square of the transfer function of the sprung mass acceleration of the reference vehicle. The resulting sprung mass acceleration PSD is integrated over frequency to yield the root-mean-square of the sprung mass acceleration per unit length of pavement traveled. The sprung mass acceleration is shown to be the main contributor of dynamic axle loads in heavy trucks, which relate to vehicle and cargo damage and also to pavement damage.

ISO Human-Computer Interaction Standards: Finding Them and What They Contain

2020 ◽  
Vol 64 (1) ◽  
pp. 400-404
Author(s):  
Paul Green
Keyword(s):  
Human Computer Interaction ◽  
Systems Engineering ◽  
User Interfaces ◽  
Task Force ◽  
Technical Committee ◽  
International Standards ◽  
Human System ◽  
International Standards Organization ◽  
Browsing Tool ◽  
Computer Interaction

An HFES Task Force is considering if, when, and which, HFES research publications should require the citation of relevant standards, policies, and practices to help translate research into practice. To support the Task Force activities, papers and reports are being written about how to find relevant standards produced by various organizations (e.g., the International Standards Organization, ISO) and the content of those standards. This paper describes the human-computer interaction standards being produced by ISO/IEC Joint Technical Committee 1 (Information Technology). Subcommittees 7 (Software and Systems Engineering) and 35 (User Interfaces), and Technical Committee 159, Subcommittee 4 (Ergonomics of Human-System Interaction), in particular, the contents of the ISO 9241 series and the ISO 2506x series. Also included are instructions on how to find standards using the ISO Browsing Tool and Technical Committee listings, and references to other materials on finding standards and standards-related teaching materials.

A Methodology for the Test Design and Evaluation of Human Whole-Body Vibration in Ground Vehicle Systems

1989 ◽  
Vol 33 (18) ◽  
pp. 1192-1196
Author(s):  
Ellen C. Haas
Keyword(s):  
Whole Body Vibration ◽  
International Standards ◽  
Whole Body ◽  
Test Design ◽  
Exposure Limits ◽  
Ground Vehicle ◽  
Body Vibration ◽  
Exposure Limit ◽  
Vehicle Systems ◽  
Iso 2631

To date, testing and evaluation of whole-body vibration in ground vehicle systems have not always fully utilized appropriate experimental design methodology, applicable statistical tests, or relevant criteria. A test design and evaluation methodology was developed to eliminate these oversights. This methodology uses inferential statistics, questionnaires, and a comparison of vibration data with representative mission scenarios. The methodology was employed in the evaluation of two alternative tracked ground vehicle designs. The independent variables were track type, terrain, vehicle speed, and crew position. The dependent variables were International Standards Organization (ISO) 2631 whole-body vibration exposure limit times at the lateral, transverse, and vertical axes. Two different multivariate analyses of variance (MANOVAs) performed on the exposure limit data indicated that all main effects, as well as several interactions, were significant (p < .01). A comparison of exposure limits to a representative mission scenario indicated that both track types would exceed ISO 2631 exposure, comfort, and fatigue limits during expected travel over cross-country terrain. Crew questionnaires also indicated crew discomfort when exposed to this type of terrain. The experiment demonstrated that the procedure was useful in helping to determine the extent that vehicle vibration permits the performance of the vehicle mission, within limits dictated by safety, efficiency, and comfort.

scholarly journals Cognitive and Physical Activity-Related Aspects of Children Associated to the Performance of the Crunning Movement

2021 ◽  
Vol 6 (1) ◽  
pp. 9
Author(s):  
Ewan Thomas ◽  
Marianna Alesi ◽  
Garden Tabacchi ◽  
Carlos Marques da Silva ◽  
David J. Sturm ◽  
...  
Keyword(s):  
Physical Activity ◽  
Children And Adolescents ◽  
Team Sports ◽  
Group Differences ◽  
Test Results ◽  
Older Children ◽  
Related Factors ◽  
Movement Performance ◽  
Individual Sports ◽  
Age Range

The aim of this investigation was to identify possible related factors associated to the performance of the crunning test in European children and adolescents. A total number of 559 children and adolescents (age range 6–14 years) of which 308 boys (55.1%) and 251 girls (44.9%), from seven European countries, were screened. A questionnaire concerning demographic and personal life-related factors and a cognitive assessment were performed. A regression analysis was conducted with the performance measures of the crunning movement. T-tests and ANCOVA were used to analyze sub-group differences. Boys have greater crunning performance values compared to girls (5.55 s vs. 7.06 s, p < 0.001) and older children perform better than younger ones (R2 −0.23; p < 0.001). Children with healthy and active habits (exercising or spending time with family members vs. reading or surfing the internet) performed better in the test. Children engaged in team sports had better crunning performances compared to those engaged in individual sports (6.01 s vs. 6.66 s, p = 0.0166). No significant association was found regarding cognitive-related aspects in either children engaged in team or individual sports and the crunning performance. Older and male children performed better in the crunning test than younger and female children. Physical activity-related aspects of children’s life are associated with crunning movement performance. No association was found between higher cognitive performance and the crunning test results.

scholarly journals Smaller organ mass with greater age, except for heart

2009 ◽  
Vol 106 (6) ◽  
pp. 1780-1784 ◽  
Author(s):  
Qing He ◽  
Stanley Heshka ◽  
Jeanine Albu ◽  
Lawrence Boxt ◽  
Norman Krasnow ◽  
...  
Keyword(s):  
African Americans ◽  
The Elderly ◽  
Left Ventricular ◽  
Fat Free Mass ◽  
Whole Body ◽  
Organ Mass ◽  
Total Body ◽  
Age Range ◽  
Negative Relationships

Autopsy/cadaver data indicate that many organs and tissues are smaller in the elderly compared with young adults; however, in vivo data are lacking. The aim of this study was to determine whether the mass of specific high-metabolic-rate organs is different with increasing age, using MRI. Seventy-five healthy women (41 African-Americans and 34 Caucasians, age range 19–88 yr) and 36 men (8 African-Americans and 28 Caucasians, age range 19–84 yr) were studied. MRI-derived in vivo measures of brain, heart, kidneys, liver, and spleen were acquired. Left ventricular mass (LVM) was measured by either echocardiography or cardiac gated MRI. Total body fat mass and fat-free mass (FFM) were measured with a whole body dual-energy X-ray absorptiometry (DXA) scanner. Multiple regression analysis was used to investigate the association between the organ mass and age after adjustment for weight and height (or DXA measures of FFM), race, sex, and interactions among these variable. No statistically significant interaction was found among age, sex, and race in any regression model. Significant negative relationships between organ mass and age were found for brain ( P < 0.0001), kidneys ( P = 0.01), liver ( P = 0.001), and spleen ( P < 0.0001). A positive relationship between LVM and age was found after adjustment for FFM ( P = 0.037). These findings demonstrate that age has a significant effect on brain, kidneys, liver, spleen, and heart mass. The age effect was independent of race and sex.

scholarly journals The Noise Level Measurements of Children’s Sound Books

2021 ◽  
Vol 17 (4) ◽  
pp. 371-379
Author(s):  
Seok-Hee Joo ◽  
Eun-Yeong Shin
Keyword(s):  
Hearing Loss ◽  
External Auditory Canal ◽  
Noise Level ◽  
Sound Intensity ◽  
International Standards ◽  
Children's Books ◽  
Children’S Books ◽  
Hearing Rehabilitation ◽  
Children's Book ◽  
International Standards Organization

Purpose: It was intended to measure the sound intensity of children's sound books and to compare them with the standards of Korea and the International Standards Organization (ISO).Methods: The loudness of 15 children’s sound books was measured at a distance of 25 cm (child’s arm length), and 2.5 cm length of external auditory canal. Measurements taken three times with each book were performed, and the overall sound intensity of the sound books and the sound intensity of each button were measured and compared.Results: Compared with the Korean standard, all the buttons of all books exceeded the standard for the sound volume of the children’s book measured at a distance of 2.5 cm. When comparing the maximum sound intensity measured at a distance of 25 cm with 85 LAmax, a total of 168 buttons of these, 25 (14.88%) were recorded as exceeding the maximum loudness. According to the standards of the ISO, all buttons in all books were below the standard 85 LAeq.Conclusion: Several children’s books are loud enough to cause noise-induced hearing loss, especially when they are placed close to the ear. Strict standards for sound children’s books are required, and it is important to put a warning on the cover of the book. It is expected that the sound intensity of the children’s sound book presented in this study can be referenced when referring to the loudness during hearing rehabilitation in children.

scholarly journals Can children's spelling of schwa vowels in stems be improved?

2010 ◽  
pp. 113-127 ◽  
Author(s):  
João Rosa ◽  
Terezinha Nunes
Keyword(s):  
Primary School ◽  
Significant Interaction ◽  
Older Children ◽  
Priming Effects ◽  
Early Signs ◽  
Priming Condition ◽  
Priming Paradigm ◽  
Written Form ◽  
Age Range ◽  
Morphological Representation

Children in the early grades of primary school do not seem to have much awareness of morphemes. In this study, a priming paradigm was used to try to detect early signs of morphological representation of stems through a spelling task presented to Portuguese children (N= 396; age range 6 to 9 years). Primes shared the stem with the targets and contained well-articulated, stressed vowels; the stems of the target words contained non-stressed schwa vowels, which typically result in spelling difficulties. If priming proved effective, the well-articulated vowels in the prime should lead to improvement in the spelling of the schwa vowels in the targets. Primes were presented in two conditions: in only-oral or in oral-plus-written form. Effectiveness of priming was assessed by comparison with a no-priming condition. There was a significant interaction between priming effects and grade. No priming effects were detected in 6- and 7-year-old children; oral-plus-written priming produced higher rates of correct vowel spelling for 8- and 9-year-olds; only-oral priming was effective in improving the vowel spelling of 9-year-olds. Thus the older children used morphological information under priming conditions but there is no evidence to suggest that younger children did so.

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