A metal speculum is a medical instrument used for dilating an opening of the body to allow light into the opening for examination or medical procedures. The ancient Greeks and Romans used the metal speculum, called a dioptra, for performing vaginal and rectal examinations and surgeries. The basic form of the these metal speculums remained relatively unchanged until the 20th century. The shape and size of the metal speculum varies, depending on the body cavity for which it is used. Originally crafted of bronze, metal speculums today are constructed of stainless steel.
Medical personnel utilize different types of speculums for different medical tasks. Most medical professionals use a metal speculum for a speculum exam, although metal speculums might be employed in surgical procedures. Plastic speculums have become more common for use in emergency rooms and doctor's clinics. These speculums are designed for a single use and then are disposed of after examination. Surgical units use the metal speculum, which can be sterlized and reused.
A metal speculum is named in more detail depending on the body opening that is inspected. For example, a medical practitioner uses a nasal speculum to inspect a patient's nasal passages. The rectal speculum is used to inspect the rectal cavity, and a pelvic speculum, sometimes called a vaginal speculum, is for the vaginal cavity. The aural speculum resembles a small funnel and is used for inspecting the interior of the ear. An eye speculum keeps the eyelids open during eye surgery.
The vaginal speculum is commonly used by gynecologists and obstetricians for the pelvic exam. The medical professional might use a vaginal speculum with one, two or three blades, depending on the type of exam. The most frequently used vaginal speculum is the bivalve graves speculum. Resembling a duck bill, the two blades separate and dilate the vaginal cavity as the medical professional turns a screw mechanism on the speculum handle. The medical practitioner usually warms the cold metal speculum to body temperature before insertion.
For anal or rectal examination or surgery, a vaginal speculum might be used, or the medical professional might use a specially designed anal speculum called an anoscopy. This narrow, rigid instrument is inserted into the anus; an interior bullet-shaped tube is removed to provide the medical professional a clear view of the lower rectum. Medical practitioners have used both the the vaginal and rectal metal speculums for more than 1,000 years.