[Development of cerebral blood flow measurement using skull impedance plethysmography]

Using skull impedance plethysmography, a developmental approach was made to the measurement of mean cerebral blood flow (mCBF) from brain volume exchanging ratio (delta V) involved in bilateral jugular venous occlusion. An experimental study thereof revealed the following results: Comparative examinations were made between total cerebral blood flow obtained by the superior sagittal sinus hydrogen clearance method and delta V X t obtained by the present approach led to the establishment of a linear correlation there between and also of the following calculating formula: mCBF = k X delta V X t (omega X sec) k: proportional coefficient t: blood flow increasing time (10 sec.) The experimental results revealed that the present approach was valid enough as an index of cerebral blood flow. Some future improvements therein seem to make also its clinical application possible. The theory and method of the present approach are described with an examination of several points raised thereby.