Abstract
An electrical impedance method has been adapted to the study of vascular changes in membranous structures. The method enables the detection of changes in the arterial volume-pulse, blood volume and fluid distribution. The changes recorded as impedance variations may be converted to volume data. The technique requires an electrode arrangement suitable for the membrane being used. Experimental work regarding the effect of the cortical steroids on the integrity of the terminal vessels, and the effect of large doses of histamine on the volume-pulse in the hamster cheek pouch lend support to the validity of the method.