【SPECIFICATION】

1). The model consists of six different sets of changes in the cervix and birth canal between the modules. 
2). The set of model checking cervical dilation of cervical size, degree of cervical change
and fetal head position with the plane between the ischial spine.
3).the first stage the expansion of the various parts of change

4). Phase One--- there is no expansion of cervix, cervical canal did not disappear, the fetal head position relationship with the ischial spine to Planar -5. 
5). Phase II-- cervical dilation 2cm, 50% of the cervical canal disappeared, fetal head position relationship with the ischial spine as -4 plane. 
6). Phase three-- cervical dilation 4cm, cervical canal disappeared, fetal head position relationship with the ischial spine is -3 plane.

7). Phase Four--- cervical dilation 5cm, cervical canal disappeared, fetal head position relationship with the ischial spine plane is 0. 
8). Phase Five-- cervical dilation 7cm, cervical canal disappeared, fetal head position relationship with the ischial spine flat to +2. 
9). Phase VI--- cervical dilation 10cm, cervical canal disappeared, fetal head position relationship with the ischial spine +5 plane.