A speculum is comprised of a shaft member having a cavity passing therethrough and an outer layer and an inner layer with a bladder, capable of holding a bio-acceptable liquid, disposed therebetween. At least one guide member runs along the lateral length of the shaft member within the cavity. An...http://www.google.fr/patents/US5795289?utm_source=gb-gplus-shareBrevet US5795289 - Speculum
