V. FINGER CUFF METHOD OF PENAZ
This method works on the principle of the unloaded arterial wall. Arterial pulsation in a finger is detected by a photoplethysmograph under a pressure cuff. The plethysmograph’s output drives a servoloop which changes the cuff pressure to maintain constant output so that the artery is held in the partially opened state. The pressure oscillations in the cuff are measured and resemble the intra-arterial pressure wave in most individuals tested. Finometer and Portapres recorders are available and are useful for the diagnosis of pseudohypertension that may occur in the elderly who may be overmedicated because of the finding of high blood pressure readings obtained with the usual cuff method.