Cervical dilation measurement instruments

摘要

Cervical dilation is measured by a V-shaped caliper instrument having connectors on the free ends of the caliper arms for securement to respectively opposed portions of the cervix, and a transducer coupled with the arms to provide an electric signal representing their mutually relative positions. The transducer suitably comprises strain gages mounted on a spring acting between the arms. The connectors can be toothed spring clips pivoted on the arms, but are preferably pins projecting generally parallel to the arms from the underfaces of outwardly turned free end portions thereof. In the latter case the arms preferably have spring guard strips extending alongside their outer faces at their ends.