|
Abstract
|
Head injury is acknowledged to be one of the more serious safety and medical management problems in both air and ground vehicle accidents. Although certain physiological phenomena and injuries are predictively observed in accident situations, little is known of the more basic mechanisms producing these phenomena and even less of the relationships between viable responses, trauma and impact characteristics.
Early injury tolerance standards were based on best estimates from isolated classical physiological experiments and judgments of clinical observations. In more recent years, revisions in injury tolerances have, unfortunately, been defined primarily in terms of fracture characteristics of cranial and facial bones with little emphasis on or serious acknowledgment of more critical physiological problems. Ironically, the philosophy of this approach had been generally discredited more than 100 years ago when Abernathy (1852), Hutchinson (1877) and Bergmann (1880), among others, supported the view that traumatic disorder of the brain can occur without structural damage. The fact that more recent investigators, such as Haynes and Lissner (1961), specifically conclude that serious and fatal brain injuries can occur without fracture, has not significantly changed the existing injury tolerance standards for a simple lack of proper information. Fortunately, following Holbourn's major work (1943), Ommaya's overview of head injury (1966) and subsequent work have emphasized again a more realistic trend in experimental head injury to define the basic mechanisms and correlate the events of impact responses with controlled impact characteristics. Such data are relative to the real accident situation where physiological responses are direct correlating factors of injury and survival status.
This report documents the physiological responses, trauma pathology and dynamic events of head impact experiments that produced a clinically defined state of cerebral concussion. It was anticipated that a better understanding of the relationships of trauma mechanisms would result in a more effective early clinical management of head injuries and more efficient methods to pre- vent or reduce serious head injury with meaningful tolerance standards for design. Prevention or reduction of incapacitating head injuries for effective evacuation procedures in survivable accidents is considered a priority safety problem. |