A DEVICE FOR ASSESSING INTRACRANIAL PRESSURES
Wade, Gerald James
An instrument has been designed to measure intracranial pressures in infants for the specific purpose of providing a clinical device to aid in the early detection of abnormal intracranial pressures. It is also useful in monitoring the intracranial pressure following surgery of the central nervous system. or .to determine whether shunting procedures are working adequately. The instrument provides a quick and reasonably accurate pressure measurement simply by placing a probe on the anterior fontanelle. Engineering design criteria and the operating principles of the instrument are fully discussed and alternative measuring devices and techniques are considered. Although clinical data is limited, a thorough analysis of the results to date is presented. A transducer, an air pump, a pressure gage, an automatic control system, and memory with visual read-out, are the basic parts of the system. The transducer is a closed-end, fluid filled device which operates on a true applanation principle. The air supply for the pneumatically operated transducer is provided by the pump which is in turn, under the control of an automated logic circuit, thus simplifying operating procedure. Basically, the instrument makes twenty separate determinations of the intracranial pressure; the meter read-out is scaled to indicate the mean of these values. Results obtained indicate that the intracranial pressure of infants with open fontanelles can be determined with an error of +-lO%, and the time required to evaluate the pressure is minimal thereby facilitating clinical use.