Week six: July 15, 2016
Lucas Gutembergue da Costa
This week we kept working on the Optoco, our most recent prototype looks like this:
Fig 1 – 3D printed box
Fig 2 – Optoco prototype
Figure 3 – Optoco prototype with the electronics
We had to iterate many times to finally get a good box to encase our electronics:
Figure 4 and 5 – iterations of the 3D printed box used to encase the LED and the photoresistor
We have also prepared different lengths and diameters of fiber optics and compared the response of the different configurations using signal vs displacement graphs. Additionally we finished and tested the code for the LED matrix that displays the results of the device. This LED matrix works similarly to a partograph, indicating the number of contractions per interval of time.
Fig 6 – LED matrix
On Thursday we went to a hospital to meet our client and a doctor that collaborates with our client. Our goal was to see a woman in labor to get a better understanding of labor contractions and evaluate how much the belly stretches during the contractions. One of the patients agreed to see us, therefore the whole team and our client had the opportunity to observe real uterine contractions. The problem we noticed is that the belly expansion during a contraction is negligible and can’t even be detected by observation. That means the concept of creating a device that sits on top of the belly and detects contractions using the expansion of the belly is not feasible. We learned in our visit that a contraction is detected by the increase in stiffness of the pregnant woman abdomen.
After the visit we discussed our observations with our client, concluding that our device is not a viable uterine contraction monitor. The idea of using fiber optic alongside with an LED and a light sensor can be used to detect contraction but the device needs to include a pressure transducer, such as a spring or an elastic material, to convert the changes in pressure of the abdomen into displacement. Since we have only one more week left for the SEED internship, Team Toco won’t be able to design this modification of the concept. Therefore we agreed with our client to pass on to her all the information we accumulated during this project, including the signal vs displacement curves of the various configurations of fiber optics, the data processing algorithm we elaborated and our CAD model files.
On Friday we had a screen printing workshop. It was really fun and I was able to screen two very nice T-shirts.
Thanks for reading!
See you on the next (and final) post!