rheoplethysmograph

== English == === Etymology === From rheo- + plethysmograph. === Noun === rheoplethysmograph (plural rheoplethysmographs) An instrument for the measurement of variation in volume of organs by measurement of variations in electric impedance ==== Derived terms ==== === References === FreePatentsOnline https://web.archive.org/web/20071013164133/http://freepatentsonline.com/3742936.html