Biomedical sciences instrumentation
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Longitudinal barriers, such as guardrails, are designed to prevent a vehicle that leaves the roadway from impacting a more dangerous object while minimizing risk of injury to the vehicle occupants. Current full-scale test procedures for these devices do not consider the effect of occupant restraints such as seat belts and airbags. The purpose of this study was to determine the extent to which restraints are used or deployed in longitudinal barrier collisions and their subsequent effect on occupant injury in these collisions. ⋯ Seat belt usage rates were approximately 60 and 80 percent for non-airbag-equipped and airbag-equipped vehicles, respectively. Compared to fully restrained occupants, relative risk of injury for no airbag/belted, airbag/unbelted, and no airbag/unbelted occupants was 1.6, 7, and 11.7, respectively. Despite these large differences in relative risk, however, 95 percent of the occupants in the analyzed data were either uninjured or sustained minor injury, which reinforces the overall effectiveness of these roadside devices.
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We have developed a system for monitoring a patient's electrocardiogram (ECG) and movement during daily activities. The complete system is mounted on chest electrodes and continuously samples the ECG and three axis accelerations. ⋯ These data are stored on a server computer and downloaded to the physician's Java mobile phone. The physician can display the data on the phone's liquid crystal display.
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Diffusion tensor imaging (DTI) has been successfully used to image the human brain and spinal cord, although there is still controversy as to which tensor-derived diffusion indices produce the greatest contrast and provide the best anatomical representation of gray and white matter within the spinal cord. The aim of this study was to determine the best diffusion indices for use in the spinal cord using the detectability index, ROC analysis, and opinion data in the form of a survey. DTI of the entire spinal cord (C1-L1) was performed on five neurologically intact human subjects at 1.5-T. ⋯ The survey indicated that the deviation of the primary eigenvalue with respect to mean diffusivity (MA1) was significantly better than all other indices at representing underlying spinal cord morphology. This is consistent with previous results showing lack of detail in ventral gray matter regions using the FA. Results indicate FA and MA1 provide the highest contrast and most accurate representation of underlying morphology, respectively.