Abstract: An assistance device and an associated obstetrical instrument, in particular of the forceps type, for extracting a fetus during childbirth having two branches. Each branch being equipped at one end with a gripping handle and at the other end with cephalic blades. The instrument further includes a measurement device using the blades and connector between the measurement device and the blade. The measurement device includes: a pressure measurement instrument configured to measure the pressure exerted by the blade on the fetus, a position measuring instrument to measure the positioning of the obstetrical instrument, a power supply, and a transmitter configured to transmit the measurements to a processing unit.

Abstract: The present invention provides a method (30) of determining mechanical properties of the pelvic cavity of a person or an animal, the pelvic cavity including a plurality of organs and the method comprising a step (34) during which pressure is measured at one or more points of the surface of one of the organs of said pelvic cavity, and during which, simultaneously, movements of a plurality of organs of said pelvic cavity are also measured. The present invention also provides a measuring device for measuring pressure in an organ of the pelvic cavity in order to perform the above method (30). The measuring device comprises an optical fiber pressure sensor mounted in a non-metallic housing, and a closed flexible reservoir mounted in said non-metallic housing and having a surface, in particular a flexible surface, that constitutes a pressure measuring surface.