Apparatus and method for monitoring intracranial pressure

Abstract

An apparatus and a method that permit the accurate measurement and continuous monitoring of the intracranial pressure of humans and vertebrates that eliminates the requirement of direct contact with the patient's head, obviates problems previously encountered with the “soft” interface between transducers and the patient, and minimizes patient discomfort during the measurement process. The apparatus includes a pair of diametrically opposed acoustic transducers controlled and monitored through a switching device by a constant frequency pulsed phase-locked loop signal generator/analyzer. The transducers provided signal data that permits a discrimination of cranial vault width using appropriate signal processing devices. Digital logic devices or microprocessor based devices permit the identification of changes in cranial vault width from which intracranial pressure changes are determined. The method includes transmitting incrementally offset (in time) interrogating acoustic signals from the transducers and receiving reflected signals that include indications of the interior distance between the cranial vault walls. Repeated transmissions and receptions permit a comparison of cranial vault signal transit times and the identification of changes in the cranial vault width. Such changes are correlated with intracranial pressure changes after reference to an initial measured pressure.