Biomedical sciences instrumentation
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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.
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Comparative Study
Head acceleration is less than 10 percent of helmet acceleration in football impacts.
Sports-related concussions constitute 20 percent of brain injuries each year in the United States. Concussion research has included a variety of instrumentation and techniques to measure head accelerations. Most recently, the Head Impact Telemetry (HIT) System (Simbex, Lebanon, NH), a wireless system that provides real-time data from impacts, is used to measure in-situ head accelerations in collegiate football. ⋯ The impact locations were on the side, back, top and just above the facemask on the front. By comparing these two measured head accelerations and the helmet acceleration during a pendulum impact, it is shown that the response of the head and the helmet vary greatly and the in-helmet system matches the head and not helmet acceleration. Specifically, head acceleration is less than 10 percent of helmet acceleration in football impacts; moreover, the HIT System is able to accurately measure the head acceleration.
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Facial bone fractures in the military can result from direct loading of night vision goggles on the orbital region. Facial fracture research has shown that increasing the area over which the load is applied increases the load tolerance. The purpose of this study is to apply this concept to reducing the risk of facial bone fracture from night vision goggle impacts. ⋯ Two impacts to the male subject with a custom face shield resulted in peak loads of 4554 N and 5101 N with no injury. The final impact to the male subject had a peak load of 2010 N with complete orbital fracture due to the absence of a countermeasure. From these tests it is shown that facial fracture risk from night vision goggle impact can be reduced using a contoured rigid face shield.
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Comparative Study Controlled Clinical Trial
Thoracic and lumbar spine accelerations in everyday activities.
The purpose of this study was to quantify thoracic and lumbar spine accelerations for men and women of different body sizes during daily activities. Measured spine accelerations were compared to determine if there were significant differences in peak accelerations based on gender, size, and spine location. ⋯ Based on the statistical analysis, it was determined that gender and body size did not have a significant effect on peak accelerations of the thoracic and lumbar spine. The findings from the present study are of great value to researchers in order to understand the acceleration patterns of the human body during low impact accelerations.