Update #3
This week, we began working with the parts that we ordered. Below we will discuss our progress in each of the 3 aspects of our project.
Edema Prevention
We bought stretchy nylon fabric to use on the shrinker that Hanger Clinic gave us. This weekend, we plan to sew the fabric on the shrinker as a drawstring, so that we can apply uniform pressure to the limb. We will also sew pressure sensors into the inner lining of the fabric and begin to take measurements using the dummy given to us by Hanger Clinic.
Skin Perfusion
We researched how reflectance based spO2 measurements are taken, so that we could better understand the circuitry of the two pulse oximeters we ordered. We learned that reflectance based pulse oximeters use red LED, infrared, and photodiodes. A practical limitation of reflectance based pulse oximetery is that poor data is taken from low density areas of skin. Heating can help skin perfusion measurements because it enlarges skin pores.
Limb Volume
Today we began programming our chip to take measurements with the soft potentiometers wrapped around the limb stump. We plan to continue familiarizing ourselves with using the soft potentiometers and the evaluation board and take measurements on the dummy this weekend.