Labour Delivery Model

This series model consists of six development phases and each part shows a state of
prenatal cervix and birth canal. The whole model demonstrates the relations
between the scope of the expanding of the orifice of the cervix, and the range of
cervical tunnels, as well as the relation between the position of the head of the fetus
and the square of ischial spine. The orifice of the cervix has no expanded, and the
cervical tunnels haven’t disappeared at all. The positional relation between the head
of the fetus and the square of the ischial spine is -5. The orifice of the cervix has expanded 2 cm bigger, and
cervical tunnels disappear 50%. The positional relation between the head of the fetus and the square of the
ischial spine is -4. The orifice of the cervix has expanded 4cm bigger, and the cervical tunnels disappear
absolutely. The positional relation between the head of the fetus and the square of the ischial spine is -3. The
orifice and cervix have expanded 5cm bigger, and the cervical tunnels disappear absolutely. The positional