A measurement device for measuring the diameter and of a cervical os, including a first connector for connecting to a first portion of the cervical os, a second connector for connecting to a second portion of the cervical os, an expandable device positioned between the first connector and the second connector, and the expendable device being expandable to measure the movement of the cervical os.
US 20070179410 A1
Mahajan, Ajay; Schwartz, Bradley; and Schwartz, Leanne, "Cervigage" (2007). Mechanical Engineering Faculty Research. 525.