Associations between ambient air pollution levels during weeks 3–7 of pregnancy and risks of cardiovascular malformations were investigated among the cohort of pregnancies reaching at least 20 weeks’ ...gestation that were conceived during January 1, 1986–March 12, 2003, in Atlanta, Georgia. Surveillance records obtained from the Metropolitan Atlanta Congenital Defects Program, which conducts active, population-based surveillance on this cohort, were reviewed to classify cardiovascular malformations. Ambient 8-hour maximum ozone and 24-hour average carbon monoxide, nitrogen dioxide, particulate matter with an average aerodynamic diameter of <10 μm (PM10), and sulfur dioxide measurements were obtained from centrally located stationary monitors. Temporal associations between these pollutants and daily risks of secundum atrial septal defect, aortic coarctation, hypoplastic left heart syndrome, patent ductus arteriosus, valvar pulmonary stenosis, tetralogy of Fallot, transposition of the great arteries, muscular ventricular septal defect, perimembranous ventricular septal defect, conotruncal defects, left ventricular outflow tract defect, and right ventricular outflow defect were modeled by using Poisson generalized linear models. A statistically significant association was observed between PM10 and patent ductus arteriosus (for an interquartile range increase in PM10 levels, risk ratio = 1.60, 95% confidence interval: 1.11, 2.31). Of the 60 associations examined in the primary analysis, no other significant associations were observed.
SRAM SER measurements show a decrease in per-bit susceptibility at the 3-nm FinFET node compared to the 5-nm FinFET node, contrary to the trend observed between the 7-nm and 5-nm FinFET nodes. Robust ...data across various supply voltages demonstrate a pronounced exponential bias influence on 3-nm FinFET SRAM SER, distinguishing it from earlier FinFET processes. Simulation and modeling attribute these trends to variations in Q_{crit} and Q_{coll} . These findings highlight that SER scaling trends in advanced FinFET processes do not necessarily align with the standard scaling trends observed in prior nodes.
Scaling trends in the alpha-particle and neutron induced SRAM SER shows an increase in the per-bit SER and percent multi-cell upsets at the 5-nm FinFET process compared to the 7-nm process. Neutron ...SER tests across process corners show that the faster process corner SER is up to 2\times higher than the slower process corner SER in 7-nm and 5-nm FinFETs. The process corner dependence of SER is attributed to differences in propagation delay and single-event transient pulse-widths.
An indoor navigation system to support the visually impaired Riehle, T. H.; Lichter, P.; Giudice, N. A.
2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society,
01/2008, Letnik:
2008
Conference Proceeding, Journal Article
Indoor navigation technology is needed to support seamless mobility for the visually impaired. A small portable personal navigation device that provides current position, useful contextual wayfinding ...information about the indoor environment and directions to a destination would greatly improve access and independence for people with low vision. This paper describes the construction of such a device which utilizes a commercial Ultra-Wideband (UWB) asset tracking system to support real-time location and navigation information. Human trials were conducted to assess the efficacy of the system by comparing target-finding performance between blindfolded subjects using the navigation system for real-time guidance, and blindfolded subjects who only received speech information about their local surrounds but no route guidance information (similar to that available from a long cane or guide dog). A normal vision control condition was also run. The time and distance traveled was measured in each trial and a point-back test was performed after goal completion to assess cognitive map development. Statistically significant differences were observed between the three conditions in time and distance traveled; with the navigation system and the visual condition yielding the best results, and the navigation system dramatically outperforming the non-guided condition.
In a continuing investigation into the mechanical factors that lead to rupture of abdominal aortic aneurysms, wall pressure and shear stress measurements are presented for steady flow through the ...series aneurysm models described in Part I. These models simulate in vivo aortic aneurysms of diameters from 3.3 to 7.5 cm; the flow rates through the models were dynamically matched to aortic flows under conditions ranging from rest to exercise. For all models, at all flow rates, a pressure maximum was found at the midpoint of the model bulge. This maximum increased with bulge diameter, suggesting that the largest aneurysms in vivo are exposed to the greatest pressures. When the flow was turbulent, the mean wall shear stress at the proximal end of the model bulge had magnitude 2 to 4 dynes/cm2, approximately equal to its value in an undilated tube. However, at the distal end of the model bulge the mean shear stress increased to 5 to 10 dynes/cm2, whereas the peak instantaneous shear stress exceeded the mean by an order of magnitude. When extrapolated to in vivo parameters, the maximum distal wall shear stress reached levels near those capable of disrupting endothelium. This suggests that turbulence in in vivo aneurysms may precipitate thrombus formation. Subsequent decreased luminal diameters in the presence of thrombus would then lessen the likelihood of turbulent flow and reduce the strength of any turbulence that did occur. It would also reduce the pressure in the aneurysmal bulge. Thus, the presence of turbulent flow may significantly affect risk of rupture.
ObjectiveTo examine the relation between congenital heart defects (CHDs) in offspring and estimated maternal occupational exposure to chlorinated solvents, aromatic solvents and Stoddard solvent ...during the period from 1 month before conception through the first trimester.MethodsThe study population included mothers of infants with simple isolated CHDs and mothers of control infants who delivered from 1997 through 2002 and participated in the National Birth Defects Prevention Study. Two methods to assess occupational solvent exposure were employed: an expert consensus-based approach and a literature-based approach. Multiple logistic regression was used to calculate adjusted ORs and 95% CIs for the association between solvent classes and CHDs.Results2951 control mothers and 2047 CHD case mothers were included. Using the consensus-based approach, associations were observed for exposure to any solvent and any chlorinated solvent with perimembranous ventricular septal defects (OR 1.6, 95% CI 1.0 to 2.6 and OR 1.7, 95% CI 1.0 to 2.8, respectively). Using the literature-based approach, associations were observed for: any solvent exposure with aortic stenosis (OR 2.1, 95% CI 1.1 to 4.1) and Stoddard solvent exposure with d-transposition of the great arteries (OR 2.0, 95% CI 1.0 to 4.2), right ventricular outflow tract obstruction defects (OR 1.9, 95% CI 1.1 to 3.3) and pulmonary valve stenosis (OR 2.1, 95% CI 1.1 to 3.8).ConclusionsThe authors found evidence of associations between occupational exposure to solvents and several types of CHDs. These results should be interpreted in light of the potential for misclassification of exposure.
Rechargeable wireless EMG sensor for prosthetic control Lichter, P A; Lange, E H; Riehle, T H ...
2010 Annual International Conference of the IEEE Engineering in Medicine and Biology,
01/2010, Letnik:
2010
Conference Proceeding, Journal Article
Surface electrodes in modern myoelectric prosthetics are often embedded in the prosthesis socket and make contact with the skin. These electrodes detect and amplify muscle action potentials from ...voluntary contractions of the muscle in the residual limb and are used to control the prosthetic's movement and function. There are a number of performance-related deficiencies associated with external electrodes including the maintenance of sufficient electromyogram (EMG) signal amplitude, extraneous noise acquisition, and proper electrode interface maintenance that are expected to be improved or eliminated using the proposed implanted sensors. This research seeks to investigate the design components for replacing external electrodes with fully-implantable myoelectric sensors that include a wireless interface to the prosthetic limbs. This implanted technology will allow prosthetic limb manufacturers to provide products with increased performance, capability, and patient-comfort. The EMG signals from the intramuscular recording electrode are amplified and wirelessly transmitted to a receiver in the prosthetic limb. Power to the implant is maintained using a rechargeable battery and an inductive energy transfer link from the prosthetic. A full experimental system was developed to demonstrate that a wireless biopotential sensor can be designed that meets the requirements of size, power, and performance for implantation.
A positive impact on cardiac arrest survival has been demonstrated with the substantial reduction in time to defibrillation provided by the widespread deployment of automated external defibrillators ...(AEDs). However, recent studies have identified the importance of performing chest compressions before defibrillation in facilitating effective recovery from long duration ventricular fibrillation (VF). Despite the importance of cardiopulmonary resuscitation (CPR), effective performance of it in the field is hampered by many problems including the dependence on rescuer technique, which is known to be variable even with trained professionals. This research seeks to enhance survival outcomes following resuscitation. A full experimental system was developed that used an instrumented CPR manikin to provide interactive CPR coaching while collecting performance data. This system was utilized in a controlled human CPR performance study comparing the differences in chest compression performance with and without visual coaching and with and without interactive performance feedback coaching. Results from the human study support a number of conclusions and recommendations. In general using any type of coaching provided improvements in all of the CPR performance measures excluding chest recoil where there was a slight decrease in performance. The statistical results also indicated that the audio/visual coaching conditions provided a more effective coaching condition with respect to chest compression rate. Most notably, the feedback conditions both provided a statistically significant or trends toward improving chest compression effectiveness and produced superior performance as a whole.
Objective The purpose of this study was to examine associations between prepregnancy body mass index (BMI) and congenital heart defects (CHDs). Study Design These analyses included case infants with ...CHDs (n = 6440) and liveborn control infants without birth defects (n = 5673) enrolled in the National Birth Defects Prevention Study (1997-2004). Results Adjusted odds ratios for all CHDs combined were 1.16 (95% confidence interval CI, 1.05–1.29), 1.15 (95% CI, 1.00–1.32), and 1.31 (95% CI, 1.11–1.56) for overweight status, moderate obesity, and severe obesity, respectively. Phenotypes associated with elevated BMI (≥25.0 kg/m2 ) were conotruncal defects (tetralogy of Fallot), total anomalous pulmonary venous return, hypoplastic left heart syndrome, right ventricular outflow tract (RVOT) defects (pulmonary valve stenosis), and septal defects (secundum atrial septal defect). Conclusion These results corroborated those of previous studies and suggested new associations between obesity and conotruncal defects and RVOT defects.
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