Noninvasive intracranial pressure monitoring.

Because skull elasticity has been demonstrated (through holographic interferometry), the assumption was made that even a small change in intracranial hydrostatic pressure might change the bitemporal diameter of the skull measurably. The authors devised a relatively noninvasive instrument for measuring skull diameter changes with changing intracranial pressure and evaluated its performance in cadavers and dogs, with encouraging results. With this method of measuring intracranial pressure, changes in pressure of as little as 2 mm Hg can be detected. The method measures relative rather than absolute pressure; it is postulated that this shortcoming can be overcome through further effort.