ASSESSMENT OF CHANGES IN INTRACRANIAL PRESSURE

摘要

A non-invasive method and apparatus for monitoring changes in intracranial pressure which removes extracranial effects from the measurements. The metho d and apparatus can include the supplying of a fixed frequency electrical outp ut to a transducer coupled to the patient's head, thereby generating an acoustical tone burst in the patient's head which generates a first echo and a second echo, the first echo reflecting from a first interface in the side of the patient's head coupled to the transducer, and the second echo reflecting from a second interface at the opposite side of the patient's head. The firs t and second echoes are received by the transducer which can generate a first electrical signal and a second electrical signal, wherein the first and seco nd electrical signals vary in accordance with the corresponding first and secon de choes. The counterbalancing phase shifts required to bring about quadrature between each of the first and second electrical signals and the fixed frequency electrical output can be measured, and values for the change in intracranial distance based on the changes in the counterbalancing phase shifts can be obtained.