1. An information processing apparatus comprising: an imaging section which emits light to a part of a biologic body at predetermined time intervals and images a vein in the biologic body so as to generate a plurality of imaged data about the vein; a vein pattern extracting section which extracts vein patterns from the plurality of imaged data about the vein; a time change detecting section which detects a time change in the vein patterns based on the plurality of vein patterns; a blood flow volume calculating section which calculates a blood flow volume in the vein based on the time change in the vein patterns; and a processing section which determines a change in pressure applied to the biologic body by the imaging section based on the time change in the vein patterns and a time change in the blood flow volume.