Graves Bivalve Vaginal Speculum — Standard Adult

William Phillips Graves redesigned Cusco’s narrow-blade speculum in Boston in the 1920s with two changes that matter every day in clinic: blade width that increases toward the tip so the lateral vaginal walls fall away from the cervix rather than pillow inward over it, and a deeper anterior blade that holds the bladder neck back without the operator-applied upward pressure that older bivalves require. The Graves is now the default speculum in the obstetric–gynaecological theatres of teaching hospitals from Karachi to Karolinska.

What the wider distal blade buys

In a parous adult the upper third of the vagina is broader than the introitus; a parallel-sided Cusco blade therefore pinches the cervix between the lateral walls just as the speculum is opened. The Graves distal flare matches the anatomy: as the blades part, the wider distal segment lifts the lateral walls outward into the lateral fornices, and the cervix sits centred in the operator’s line of sight against the posterior-fornix mucosa.

Standard sizing

This standard model is calibrated to the parous-adult median; the small (75 × 20 mm), medium (95 × 35 / 95 × 30) and large (105 × 33 / 115 × 35) variants address the size range each operator’s catchment will see. The side-screw locks aperture without operator pressure.