scholarly journals Morphological Variation In Paediatric Lower Limb Bones

2021 ◽  
Author(s):  
Laura Carman ◽  
Thor Besier ◽  
Julie Choisne
Keyword(s):  
Medical Imaging ◽  
Lower Limb ◽  
Mean Squared Error ◽  
Bone Geometry ◽  
Principal Component ◽  
Paediatric Population ◽  
Population Based ◽  
Linear Scaling ◽  
Shape Variation ◽  
Shape Model

Abstract Available methods for generating paediatric musculoskeletal geometry are to scale generic adult geometry, which is widely accessible but can be inaccurate, or to obtain geometry from medical imaging, which is accurate but time-consuming and costly. A population-based shape model is required to generate accurate and accessible musculoskeletal geometry in a paediatric population. The pelvis, femur, and tibia/fibula were segmented from 333 CT scans of children aged 4-18 years. Bone morphology variation was captured using principal component analysis (PCA). Subsequently, a shape model was developed to predict bone geometry from demographic and linear bone measurements and validated using a leave one out analysis. The shape model was compared to linear scaling of adult and paediatric bone geometry. The PCA captured growth-related changes in bone geometry. The shape model predicted bone geometry with root mean squared error (RMSE) of 2.91±0.99mm in the pelvis, 2.01±0.62mm in the femur, and 1.85±0.54mm in the tibia/fibula. Linear scaling of an adult mesh produced RMSE of 4.79±1.39mm in the pelvis, 4.38±0.72mm in the femur, and 4.39±0.86mm in the tibia/fibula. We have developed a method for capturing and predicting lower limb bone shape variation in a paediatric population more accurately than linear scaling without using medical imaging.

scholarly journals Low acuity paediatric emergency visits under single-payer universal health insurance in Taiwan, 2000–2015: a population-based repeated cross-sectional design

BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e042084
Author(s):  
I-Anne Huang ◽  
Yiing-Jenq Chou ◽  
I-Jun Chou ◽  
Yu-Tung Huang ◽  
Jhen-Ling Huang ◽  
...  
Keyword(s):  
Health Insurance ◽  
Paediatric Population ◽  
Population Based ◽  
Universal Health Insurance ◽  
Cross Sectional ◽  
Single Payer ◽  
Insurance Programme ◽  
Ed Visits ◽  
Cross Sectional Design ◽  
Universal Health

ObjectivesEmergency services utilisation is a critical policy concern. The paediatric population is the main user of emergency department (ED) services, and the main contributor to low acuity (LA) ED visits. We aimed to describe the trends of ED and LA ED visits under a comprehensive, universal health insurance programme in Taiwan, and to explore factors associating with potentially unnecessary ED utilisation.Design and settingWe used a population-based, repeated cross-sectional design to analyse the full year of 2000, 2005, 2010 and 2015 National Health Insurance claims data individually for individuals aged 18 years and under.ParticipantsWe identified 5 538 197, 4 818 213, 4 401 677 and 3 841 174 children in 2000, 2005, 2010 and 2015, respectively.Primary and secondary outcome measuresWe adopted a diagnosis grouping system and severity classification system to define LA paediatric ED (PED) visits. Generalised estimating equation was applied to identify factors associated with LA PED visits.ResultsThe annual LA PED visits per 100 paediatric population decreased from 10.32 in 2000 to 9.04 in 2015 (12.40%). Infectious ears, nose and throat, dental and mouth diseases persistently ranked as the top reasons for LA visits (55.31% in 2000 vs 33.94% in 2015). Physical trauma-related LA PED visits increased most rapidly between 2000 and 2015 (0.91–2.56 visits per 100 population). The dose–response patterns were observed between the likelihood of incurring LA PED visit and either child’s age (OR 1.06–1.35 as age groups increase, p<0.0001) or family socioeconomic status (OR 1.02–1.21 as family income levels decrease, p<0.05).ConclusionDespite a comprehensive coverage of emergency care and low cost-sharing obligations under a single-payer universal health insurance programme in Taiwan, no significant increase in PED utilisation for LA conditions was observed between 2000 and 2015. Taiwan’s experience may serve as an important reference for countries considering healthcare system reforms.

scholarly journals Variation of the Three-Dimensional Femoral J-Curve in the Native Knee

2021 ◽  
Vol 11 (7) ◽  
pp. 592
Author(s):  
Sonja A. G. A. Grothues ◽  
Klaus Radermacher
Keyword(s):  
Geometric Parameter ◽  
Knee Kinematics ◽  
Size Variation ◽  
Principal Component ◽  
Parameter Analysis ◽  
Patient Specific ◽  
3D Analysis ◽  
Relative Location ◽  
Shape Variation ◽  
J Curve

The native femoral J-Curve is known to be a relevant determinant of knee biomechanics. Similarly, after total knee arthroplasty, the J-Curve of the femoral implant component is reported to have a high impact on knee kinematics. The shape of the native femoral J-Curve has previously been analyzed in 2D, however, the knee motion is not planar. In this study, we investigated the J-Curve in 3D by principal component analysis (PCA) and the resulting mean shapes and modes by geometric parameter analysis. Surface models of 90 cadaveric femora were available, 56 male, 32 female and two without respective information. After the translation to a bone-specific coordinate system, relevant contours of the femoral condyles were derived using virtual rotating cutting planes. For each derived contour, an extremum search was performed. The extremum points were used to define the 3D J-Curve of each condyle. Afterwards a PCA and a geometric parameter analysis were performed on the medial and lateral 3D J-Curves. The normalized measures of the mean shapes and the aspects of shape variation of the male and female 3D J-Curves were found to be similar. When considering both female and male J-Curves in a combined analysis, the first mode of the PCA primarily consisted of changes in size, highlighting size differences between female and male femora. Apart from changes in size, variation regarding aspect ratio, arc lengths, orientation, circularity, as well as regarding relative location of the 3D J-Curves was found. The results of this study are in agreement with those of previous 2D analyses on shape and shape variation of the femoral J-Curves. The presented 3D analysis highlights new aspects of shape variability, e.g., regarding curvature and relative location in the transversal plane. Finally, the analysis presented may support the design of (patient-specific) femoral implant components for TKA.

An Accurate, Robust and Low Dimensionality Deep Learning Localization Approach in DM-MIMO Systems Based on RSS

2021 ◽  
Author(s):  
Seyedeh Samira Moosavi ◽  
Paul Fortier
Keyword(s):  
Massive Mimo ◽  
Clustering Algorithm ◽  
Mean Squared Error ◽  
Mimo Systems ◽  
Principal Component ◽  
Base Station ◽  
Location Estimation ◽  
Similar Data ◽  
High Coverage ◽  
Single Antenna

Abstract Currently, localization in distributed massive MIMO (DM-MIMO) systems based on the fingerprinting (FP) approach has attracted great interest. However, this method suffers from severe multipath and signal degradation such that its accuracy is deteriorated in complex propagation environments, which results in variable received signal strength (RSS). Therefore, providing robust and accurate localization is the goal of this work. In this paper, we propose an FP-based approach to improve the accuracy of localization by reducing the noise and the dimensions of the RSS data. In the proposed approach, the fingerprints rely solely on the RSS from the single-antenna MT collected at each of the receive antenna elements of the massive MIMO base station. After creating a radio map, principal component analysis (PCA) is performed to reduce the noise and redundancy. PCA reduces the data dimension which leads to the selection of the appropriate antennas and reduces complexity. A clustering algorithm based on K-means and affinity propagation clustering (APC) is employed to divide the whole area into several regions which improves positioning precision and reduces complexity and latency. Finally, in order to have high precise localization estimation, all similar data in each cluster are modeled using a well-designed deep neural network (DNN) regression. Simulation results show that the proposed scheme improves positioning accuracy significantly. This approach has high coverage and improves average root-mean-squared error (RMSE) performance to a few meters, which is expected in 5G and beyond networks. Consequently, it also proves the superiority of the proposed method over the previous location estimation schemes.

Variability in Muscle Recruitment Strategy Between Operators During Assisted Assembly Tasks

2018 ◽  
Author(s):  
Yingxin Qiu ◽  
Keerthana Murali ◽  
Jun Ueda ◽  
Atsushi Okabe ◽  
Dalong Gao
Keyword(s):  
Upper Limb ◽  
Lower Limb ◽  
Wrist Joint ◽  
Principal Component ◽  
Classification Performance ◽  
Body Motion ◽  
Recruitment Strategy ◽  
Support Vector ◽  
Recruitment Strategies ◽  
Muscle Recruitment

This paper reports the variability in muscle recruitment strategies among individuals who operate a non-powered lifting device for general assembly (GA) tasks. Support vector machine (SVM) was applied to the classification of motion states of operators using electromyography (EMG) signals collected from a total of 15 upper limb, lower limb, shoulder, and torso muscles. By comparing the classification performance and muscle activity features, variability in muscle recruitment strategy was observed from lower limb and torso muscles, while the recruitment strategies of upper limb and shoulder muscles were relatively consistent across subjects. Principal component analysis (PCA) was applied to identify key muscles that are highly correlated with body movements. Selected muscles at the wrist joint, ankle joint and scapula are considered to have greater significance in characterizing the muscle recruitment strategies than other investigated muscles. PCA loading factors also indicate the existence of body motion redundancy during typical pick-and-place tasks.

scholarly journals Individual variation of the masticatory system dominates 3D skull shape in the herbivory-adapted marsupial wombats

2019 ◽  
Author(s):  
Vera Weisbecker ◽  
Thomas Guillerme ◽  
Cruise Speck ◽  
Emma Sherratt ◽  
Hyab Mehari Abraha ◽  
...  
Keyword(s):  
Individual Variation ◽  
Principal Component ◽  
Individual Variability ◽  
Shape Variation ◽  
Mandibular Ramus ◽  
Geometric Morphometric ◽  
Skull Shape ◽  
Marsupial Species ◽  
Masticatory System ◽  
The Individual

AbstractBackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, shape variation should not be dominated by allometry; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of thre species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraint act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.

Breakfast patterns and weight status among adolescents – a study on the Brazilian National Dietary Survey 2008-2009

2021 ◽  
pp. 1-24
Author(s):  
Bruna Kulik Hassan ◽  
Diana Barbosa Cunha ◽  
Roberta de Oliveira Santos ◽  
Valéria Troncoso Baltar
Keyword(s):  
Dietary Patterns ◽  
Weight Status ◽  
Principal Component ◽  
Population Based ◽  
Fruit Juices ◽  
Principal Component Factor Analysis ◽  
Data Variability ◽  
Survey Sample ◽  
Mixed Pattern ◽  
The Relationship

Abstract Examine the composition of breakfast concerning weight status is essential for evaluating adolescent health and understanding this gap. This study aimed to identify breakfast patterns and investigate the relationship with weight status among Brazilian adolescents. We used a subsample of 7,425 adolescents aged 10-19 years from the 2008-2009 Brazilian Household Budget Survey. Breakfast eaters were those with intake of at least 50 kcal (209.2kJ) between 5 and 10 a.m. Breakfast dietary patterns were derived by principal component factor analysis with varimax rotation. We performed logistic regression analyses between breakfast patterns and weight status, considering the complexity of the survey sample design. Three breakfast patterns were identified explaining 44.8% of data variability: (1) the Cereal, protein, fruit beverages and Northern/Northeastern pattern, characterized by high consumption of cookies, meats, dairy products, preparations with corn, eggs, fruit juices/fruit drinks/soy-based drinks, tubers/roots/potatoes, and cereals, and negative adherence to cold cut meat and savory snacks/crackers; (2) the Protein-based pattern, characterized by positive loadings for cold cut meat, milk and cheese, and negative for cookies, fruit juices/fruit drinks/soy-based drinks, tubers/roots/potatoes, and cereals; and (3) the Mixed pattern, with positive loadings for cakes, coffee/tea, bread, fruit juices/fruit drinks/soy-based drinks, chocolate/desserts, and savory snacks/crackers. No association was found between skipping and weight status. Overweight adolescents had lower adherence to the Cereal, protein, fruit beverages and Northern/Northeastern pattern pattern (OR=0.67; 95% CI 0.47; 0.96). This is the first study to address dietary patterns at the meal level with adolescent population-based data, which requires further investigation.

scholarly journals Severity of COVID-19 in children with cancer: Report from the United Kingdom Paediatric Coronavirus Cancer Monitoring Project

2020 ◽  
Author(s):  
Gerard C. Millen ◽  
Roland Arnold ◽  
Jean-Baptiste Cazier ◽  
Helen Curley ◽  
Richard G. Feltbower ◽  
...  
Keyword(s):  
Severe Infection ◽  
Paediatric Population ◽  
Population Based ◽  
Children With Cancer ◽  
The United Kingdom ◽  
Increased Risk ◽  
Polymerase Chain ◽  
The Uk ◽  
Active Care ◽  
Care Support

Abstract Background Children with cancer are frequently immunocompromised. While children are generally thought to be at less risk of severe SARS-CoV-2 infection than adults, comprehensive population-based evidence for the risk in children with cancer is unavailable. We aimed to produce evidence of the incidence and outcomes from SARS-CoV-2 in children with cancer attending all hospitals treating this population across the UK. Methods Retrospective and prospective observational study of all children in the UK under 16 diagnosed with cancer through data collection from all hospitals providing cancer care to this population. Eligible patients tested positive for SARS-CoV-2 on reverse transcription polymerase chain reaction (RT-PCR). The primary end-point was death, discharge or end of active care for COVID-19 for those remaining in hospital. Results Between 12 March 2020 and 31 July 2020, 54 cases were identified: 15 (28%) were asymptomatic, 34 (63%) had mild infections and 5 (10%) moderate, severe or critical infections. No patients died and only three patients required intensive care support due to COVID-19. Estimated incidence of hospital identified SARS-CoV-2 infection in children with cancer under 16 was 3%. Conclusions Children with cancer with SARS-CoV-2 infection do not appear at increased risk of severe infection compared to the general paediatric population. This is reassuring and supports the continued delivery of standard treatment.

scholarly journals Association between neuraxial anaesthesia or general anaesthesia for lower limb revascularisation surgery in adults and clinical outcomes: population based comparative effectiveness study

BMJ ◽  
2020 ◽  
pp. m4104
Author(s):  
Derek J Roberts ◽  
Sudhir K Nagpal ◽  
Dalibor Kubelik ◽  
Timothy Brandys ◽  
Henry T Stelfox ◽  
...  
Keyword(s):  
Hospital Stay ◽  
General Anaesthesia ◽  
Lower Limb ◽  
Odds Ratio ◽  
Instrumental Variable ◽  
Length Of Hospital Stay ◽  
Population Based ◽  
Neuraxial Anaesthesia ◽  
Renal Complications ◽  
Comparative Effectiveness Study

Abstract Objective To examine the associations between neuraxial anaesthesia or general anaesthesia and clinical outcomes, length of hospital stay, and readmission in adults undergoing lower limb revascularisation surgery. Design Comparative effectiveness study using linked, validated, population based databases. Setting Ontario, Canada, 1 April 2002 to 31 March 2015. Participants 20 988 patients Ontario residents aged 18 years or older who underwent their first lower limb revascularisation surgery in hospitals performing 50 or more of these surgeries annually. Main outcome measures Primary outcome was 30 day all cause mortality. Secondary outcomes were in-hospital cardiopulmonary and renal complications, length of hospital stay, and 30 day readmissions. Multivariable, mixed effects regression models, adjusting for patient, procedural, and hospital characteristics, were used to estimate associations between anaesthetic technique and outcomes. Robustness of analyses were evaluated by conducting instrumental variable, propensity score matched, and survival sensitivity analyses. Results Of 20 988 patients who underwent lower limb revascularisation surgery, 6453 (30.7%) received neuraxial anaesthesia and 14 535 (69.3%) received general anaesthesia. The percentage of neuraxial anaesthesia use ranged from 0.6% to 90.6% across included hospitals. Furthermore, use of neuraxial anaesthesia declined by 17% over the study period. Death within 30 days occurred in 204 (3.2%) patients who received neuraxial anaesthesia and 646 (4.4%) patients who received general anaesthesia. After multivariable, multilevel adjustment, use of neuraxial anaesthesia compared with use of general anaesthesia was associated with decreased 30 day mortality (absolute risk reduction 0.72%, 95% confidence interval 0.65% to 0.79%; odds ratio 0.68, 95% confidence interval 0.57 to 0.83; number needed to treat to prevent one death=139). A similar direction and magnitude of association was found in instrumental variable, propensity score matched, and survival analyses. Use of neuraxial anaesthesia compared with use of general anaesthesia was also associated with decreased in-hospital cardiopulmonary and renal complications (odds ratio 0.73, 0.63 to 0.85) and a reduced length of hospital stay (−0.5 days, −0.3 to−0.6 days). Conclusions Use of neuraxial anaesthesia compared with general anaesthesia for lower limb revascularisation surgery was associated with decreased 30 day mortality and hospital length of stay. These findings might have been related to reduced cardiopulmonary and renal complications after neuraxial anaesthesia and support the increased use of neuraxial anaesthesia in patients undergoing these surgeries until the results of a large, confirmatory randomised trial become available.

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