This week started out strong as we worked on 3D printed boxes to mount our fiber optic cables and the electronic components (LED and photoresistor).

At first the box had no back or lid, so as Chimwe and I started testing it we found external light had a large effect.  Depending where we sat, our shadows could change the light levels that we recorded and even black tape, so Zach and Lucas kept iterating boxes until we had a slide on lid and a back. The next day we added hooks to each side so we can attach a belt and elastic.  The belt that we made snaps onto a hook at one end and has velcro around the rest so that it is adjustable in size.  The two boxes connected by the sewing elastic is shown below.

Once we had these boxes, we conducted a series of tests to compare the 3mm and 1.5mm diameter fiber optic cables as well as whether each was 4in or 6in long.  Due to the successful mounting boxing, we were able to get very consistent results for each test.  We found that the 3mm diameter carried more light so that we got a bigger range of light levels as we pulled the boxes apart.

Meanwhile, some of my teammates had been working on the code for our LED paragraph display (a paragraph is how contractions are recorded when checked by manual palpation, such as in Malawi).  Each column represents a 10 minute interval, each LED that is turned on represents a contraction, and each color represents how long the contraction lasted.  Below is an example display we made just by moving the boxes apart and together numerous times.

 

Below is our final product: the two boxes with fiber optic and elastic between and a belt to go around

 

On Thursday we got the opportunity to go to Memorial Hermann Hospital with out client to observe a woman in labor.  What we found was that the belly doesn’t stretch during a contraction, as we had been told when presented with our project.  We were also able to feel her belly before and during a contraction and the difference in stiffness of the belly is like the difference between pressing against your chin and your nose– not a lot. Unfortunately, this means that the concept behind our project doesn’t work in itself, but parts of what we have worked on could still be used in the future.  If, for example, a future group were to try a vertically arranged piece of fiber optic, our mounting boxes may still be used and the code would be the same or very similar.  It was also a valuable lesson in the differences in communication different professions may have, for example a doctor versus an engineer.  Our client told us she had talked to the doctors in Malawi who kept saying that stretching does occur during contractions, but now we know that what happens is not what we as engineers interpret as stretching.  Despite things not going as planned, I still feel the work we have done was worthwhile.