Experimental approach for monitoring surface brain pressure

✓ A method for monitoring brain surface pressure through the intact dura has been designed based upon the concept of a coplanar, non-sensitive ring transducer. The transducer detects the underlying brain pressure while the stretching forces of the dural membrane are dissipated at the outer ring. The strain gauge consists of a piezo-resistive silicon-chip sensing element and a dummy element that provides temperature compensation. Cisternal cerebrospinal fluid (CSF) and brain surface pressures were monitored simultaneously in dogs under general anesthesia, both before and after increased intracranial pressure was produced experimentally. A difference was found between CSF and brain surface pressures. Possible explanations for this observation are discussed.