Here are some pictures of our experiments with different sensors (buttons) and materials for the contraction monitor ball, that the women in labor sqeezes if she is having a contraction.
Our favorite is the big red button (picture 1) put into a latex glove which is filled with cotton (pillow stuffing). It is soft, comfortable, cheap, easy to produce, robust and reliable.
We also started programming the arduino to record when the ball is squeezed, indicating that the women is having contraction. Grace posted the pseudo code, that we are working on.
The next step will be to connect it to the display and get everything running!