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
relation between the head of the fetus and the square of the ischial spine is
0.