Relationship of carotid pressure and end point during acceleration

¹ U.S. Naval Air Development Center, Aviation Medical Acceleration Laboratory, Johnsville, Pennsylvania

Simultaneous observations have been made of the occurrence of an end point of unconsciousness and carotid blood pressure in rhesus monkeys during positive acceleration. The data indicate that the carotid pressure is influenced initially by a maneuver which gives rise to a positive wave of pressure that is well coordinated with the onset of tangential acceleration, while positive acceleration is at a very low level. Following this, there is a pressure drop that can be described by a time constant, that is, a function of peak g. The data indicate that the end point occurs after a constant interval following the pressure minimum and is therefore related to the slope of the blood pressure curve. The significance of this observation with respect to blood supply is discussed.