Reflections on the project - future challenges

Today was our final presentation, and it was exciting to share our final prototype and design process with our classmates and instructors.

Some thoughts that we had about challenges that need to be addressed in the future:

- testing the chemical tests with bacteria in order to determine the sensitivity and specificity of the tests- at what levels can bacteria be detected? Is it too high such that we will only detect bacteria when it is too late to prevent infection? Is it too low such that the test will yield false positives and nurses will no longer pay attention to the test?
- How do we ensure that the detection pad will not be contaminated when it is manufactured? Where can it be manufactured such that sterility is maintained, without increasing the cost of manufacturing the device?
- How much time should we allow for detection? Wicking time must be shorter than the time interval after which the dressing is changed in order for the device to be useful.
- How will we ensure that the device is implemented properly? That hospital staff are held accountable to changing the catheter dressing when bacteria is detected? That parents will know how to use the device and won't be afraid to take charge of their newborn's care?
- How will we ensure that the device remains safe? That the wick remains sterile so as not to introduce infection? That the chemicals are completely encased so that no toxic chemicals are in contact with the newborn?

We hope that if a future Dlab student continues this work, they will try to address one or more of these challenges.

Thank you!
Neta, Thais, Stephanie

last-minute presentation prep!

We're doing one last test of our prototype in water versus nitrite, and preparing the one-minute pitch. Full speed ahead!

- steph, neta, thais

Finished the poster!

Nososano is on its way to the DLab health presentation on Saturday. We have our compass, our pugh chart, design specs, and a very ugly model baby. Excellent.

- steph, neta, thais

Prototyping

We have tested multiple wick lengths and possible sticker designs. Having the wick divide into lanes, each containing a different biochemical test proved to be very efficient.

The picture on the left is such an example. The right most lane contain Griess reagent which detect the presence of nitrites (pink/yellow). The left most lane contains pH paper. The wick was placed inside an Eppendorf tube containing approximately 1mM NaNO2 and blue dye. It took about 20min for the solution to reach the sticker through a 10cm long heath shrink insulated wick. Wicking continues even after solution has run along the wick due to absorbent pad in the sticker.

Additionally, we tested the wicking properties of our cotton thread if instead of being place in direct contact with liquid, it was placed in contact with a moist calcium alginate dressing. Our experiments show that, though slower, the cotton thread is still able to wick liquid from the most membrane.

We ran this experiment after our reviewers voiced concerns about our initial prototype where a wet gauze (or cotton) would be place at the vicinity of the entry point (needle) to act as the source of moist where the cotton thread could wick from. As it turns out, bacteria are fond of dark, humid, environments and this aspect of our device could potentially cause IV infections. We are considering making use of the alginate dressings to overcome this limitation, though further experiments are necessary.

-Thais

quick to-do list from tonight! final stretch...

Things we have:
- nitrate test with different dilutions

Things we don’t know:
- how much nitrate bacteria produce?? - steph

Things to do tonight:
Wicking:
- test wicking. take picture.
- time it! How many hours to wick?
- how is it going to have liquid?
Bandage:
- pick which type of bandage to do – napkin?
- poster outline based on examples

- steph

Quick weekend update

Neta and I did trials of the Nitrite test for Enterobacteria, using Griess' reagent and an assortment of different bandages. We did different dilutions of the NaNO2 solution, and results look promising! Detection was strong even at 0.007M (the lowest we tried) More information to be added - but for now, I'm going to class =)

- steph