I haven’t posted for this past week because we’ve been full steam ahead on our Phototherapy Dosing Meter project at the Poly, and wifi’s been pretty spotty lately. We’ve made significant progress last week, though, and anticipate finishing out the project by the end of this week.

We started by comparing and contrasting the Engineers without Borders (EWB) analog, Rice analog, Poly digital, and commercially available models. We brought a Rice model with us, Professor Molyneux (1) let us borrow an EWB one from QECH, we read over the final report for the Poly one (2), and found user manuals for the commercial models online.

We decided to go with a digital model to avoid the drawback of calibration drift that accompanies the less expensive analog designs. With an analog ammeter, extended use or rough handling of the device can lead to changes in the way the mechanical components operate which would result in inaccurate readings.

Much of our design ideas draw from the aforementioned Poly design, but one of the large changes we made was in the device housing. We visited the Chatinkha Ward at QECH where the phototherapy lights are implemented and spoke with nurses there to gather more contextual information about how are device would be used. Then, we spent one afternoon brainstorming different designs and even set up a phototherapy light at the Poly to get a better feel for how each proposed design would interface with the existing set-up at QECH.

Our largest remaining tasks for this project are to actually build the casing and then to calibrate our device with a commercially available model that we will have access to at the end of this week. (Calibration is still initially required for digital models to match up the current generated by the photodiode and the corresponding irradiance. So far we haven’t been able to identify a programmable correlation between the two.) Aside from these tasks, we will also spend some time tomorrow visiting the Physical Assets Management (PAM) department at QECH to scout out another design project for us to work on this summer. I’m very excited for this visit and can’t wait to see how a global health design project evolves when it is being designed across the street from where it will be used rather than across the ocean.

*********************************************************

(1) The previous head of Pediatrics at QECH

(2)  We had a report in lieu of the prototype because it had since be disassembled to reuse the components for other students’ design projects. Apparently, this is common practice for many of the design projects at the Poly, but the documentation and records they kept were so thorough it didn’t pose much of a problem for us.

 

 

All of our brainstormed casing ideas laid out. My personal favorite is Christina’s baby doll design. It is on the far right on the second to last row. Eliminated for availability of materials and effectiveness, but not cuteness factor. Way to think outside of the box, Christina!