PLETHYSMOGRAPH

‖Pleth″ys‐mo‐graph (?), n. [[Gr. � an enlargement + -graph.]] (Physiol.) An instrument for determining and registering the variations in the size or volume of a limb, as the arm or leg, and hence the variations in the amount of blood in the limb. — Pleth′ys‐mo‐graph″ic (#), a.