Idiopathic elevated episcleral venous pressure with secondary glaucoma.

PURPOSE: Idiopathic elevated episcleral venous pressure (IEEVP) is a rare condition that can lead to glaucoma, which can be difficult to manage. This case report aims to educate clinicians on the importance of considering IEEVP in the differential diagnosis of elevated intraocular pressure (IOP) in the presence of engorged episcleral veins. CASE REPORT: We describe a patient who presented to the office with high IOPs in the presence of engorged episcleral veins. We diagnosed the patient with glaucoma and referred the patient to a glaucoma specialist. The elevated IOP became difficult to manage medically, and the patient underwent a trabeculectomy in the right eye. We eventually diagnosed the patient with IEEVP. CONCLUSIONS: Although rare, IEEVP should be considered when the patient presents with elevated IOP in the presence of engorged episcleral veins. Idiopathic elevated episcleral venous pressure is often difficult to manage both medically and surgically.

Biomechanics of side impact injuries: evaluation of seat belt restraint system, occupant kinematics and injury potential.

Side impact crashes are the second most severe motor vehicle accidents resulting in serious and fatal injuries. One of the occupant restraint systems in the vehicle is the three point lap/shoulder harness. However, the lap/shoulder restraint is not effective in a far-side crash (impact is opposite to the occupant location) since the occupant may slip out of the shoulder harness. The present comprehensive study was designed to delineate the biomechanics of far-side planar crashes. The first part of the study involves a car-to-car crash to study the crash dynamics and occupant kinematics; the second part involves an epidemiological analysis of NASS/CDS 1988-2003 database to study the distribution of serious injury; the third part includes the mathematical MADYMO analysis to study the occupant kinematics in detail; and the fourth part includes an in-depth analysis of a real world far-side accident to delineate the injury mechanism and occupant kinematics. Results indicate that the shoulder harness is ineffective in far-side crashes. The upper torso of the belted driver dummy slips out of the shoulder harness and interacted with the opposite vehicle interior such as the door panel. The unbelted occupants had a similar head injury severity pattern compared to belted occupants. The present study is another step to advance towards better understanding of the prevention, treatment and rehabilitation of side impact injuries.

Biomechanical injury evaluation of laminated side door windows and sunroof during rollover accidents.

Significantly more fatalities and serious injuries occur due to ejection in roll over accidents. The present study was conducted to determine the occupant retention and head-neck injury potential aspects of laminated glass in side door windows and sunroofs during roll over accidents. The test protocol for this study was based on National Highway Traffic Safety Administration (NHTSA) studies for advanced glazing. The impact study of 18 kg with head-neck form was conducted on laminated glass of side doors and sunroofs from production vehicles. The drop speed was varied from 11 to 16 kph. The Hybrid III 50% male dummy head-neck form was impacted on the approximately center of the glass portion of the windows. The head injury criteria, head resultant acceleration, and neck loads and moments were quantified. A series of drop tests were conducted on roll down side windows with laminated glass. The head-neck biomechanical parameters were well below the critical value injury tolerance limits. Results indicated that the glass contained the dummy assembly and the head-neck biomechanical parameters were below the critical value injury tolerance limits in simulated rollover accidents. The present study demonstrates that head-neck injury is unlikely due to laminated glass side windows and sunroof laminated glass used in production vehicles during rollover accidents and that the dummy is contained by the laminated glazing.

Biomechanical analysis of padding in child seats and head injury.

Head injury is a common finding for infants and young children involved in automobile accidents. Although the child restraint seats have increased the level of safety for the pediatric population, skull fracture and/or brain injury occur during the interaction between the child's head and interior of the car seats with no padding. The introduction of effective and sufficient padding may significantly reduce the head injury. The present study was designed to evaluate the biomechanical effects of padding in child seats to reduce the potential for head injury. A head drop test of a six-month old anthropomorphic dummy was conducted. The side of the dummy head impacted the interior wing of child car seats of relatively soft and stiff materials, and a rigid metal plate at velocities of 2.2, 4.5 and 6.7 m/s. In all tests, three types of padding environments were used (no padding, comfort foam, 16 to 19 mm polypropylene padding). All data were collected at 10 kHz and filtered. A total of 39 tests were conducted. The head injury criteria (HIC), and head acceleration, and head angular acceleration were obtained. The HIC was calculated over a 36 ms interval from the resultant tri-axial acceleration. The angular accelerations were derived from the angular velocity data. The head injury biomechanical parameters decreased with the addition of padding. The HIC, peak acceleration, and angular acceleration were reduced up to 91%, 80%, and 61% respectively. The present results emphasize the importance of energy absorbing padding to provide an improved safety environment in child car seats.

Biomechanical analysis of head-neck force in hybrid III dummy during inverted vertical drops.

The hybrid III dummy has been used extensively for crash testing. The comparison between the cadaver and dummy data provides the biofidelic nature of dummy head-neck system to predict cervical spine injury as a function of applied force. The existing dummy data are limited to a lower drop height up to 0.5 m. The present study quantified the head-neck biomechanical response of the dummy up to a drop height of 1.20 m. At 0.15 m, the head force was 5740 N and 5695 N at the upper neck and 4231 N at the lower neck. At 0.6 m, the head force was 13,000 N and 12,000 N at the upper neck and 8900 N at the lower neck. At 1.2 m, the calculated head force was 19,500 N and 18,600 N at the upper neck and 13,500 N at the lower neck. The present results closely match with data of previous studies. The data indicated that the hybrid III system transmits about 70 to 75% of the applied force from the head or upper neck to the lower neck area. In contrast, the cadaver studies showed for drops from 0.9 to 1.5 m, about 20 to 30% of the applied force was transmitted from the head to the lower neck. The comparison demonstrates the capability of the Hybrid III dummy head-neck force response to realistically predict injury and also the need for comparing the dummy's response to the human head neck force data for injury.

Biomedical engineering analysis of glass impact injuries.

This article outlines the history, development, and safety aspects of glass and its use in motor vehicles. It traces the manufacture and describes the characteristics of laminated and tempered glass. It further compares the differences in injuries caused by impact with laminated and tempered glass. The development, use, and results of high penetration resistance (HPR) laminated glass for windshields are examined. Head and neck injuries from impact with glass and glazing structures are delineated. Results of studies with laminated and tempered glass are presented. The probability and severity of injuries occurring secondary to partial or full ejection of vehicle occupants are discussed, and the differences between the performance of laminated and tempered glass are highlighted. Current research to quantify head and neck injury parameters caused by glass impact during rollover is described. The biomechanics of head and neck injury assessment and the development of injury prediction parameters and reference values, respectively, are reviewed.