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

Concept to Commercialization 2.0

Milestone	How Will We Achieve This?
Ability to communicate the usefulness of our design	Our blog has been the main tool in communicating our ideas. We devoted a lot of time into accruing detailed information from people in Nicaragua in order to maximize the impact of our prototype.
Prove our design is better than current market alternatives	There are bacteria detection devices and test in the market, however, these tend to require high resources or are specific to a small group of bacteria. Our design incorporates multiple biochemical tests while keeping the cost low, allowing for local manufacturing and innovation.
Understand the setting for the use of our technology	Our design is intended for use in the NICU at the Ocotal hospital in Nicaragua. Skin infections in newborns from 0-7 days, are fairly common, especially when babies need IVs for an extended amount of time. These babies are often immunocompromised and develop infections readily if the appropriate measures are not taken.
Proof of the effectiveness of our design	All tests used have been extensively described in the literature for decades.
Prove that our design is safe	Even though some of the chemicals present toxicity, our device incorporates the biochemical test in an isolated compartment, which prevents direct contact with the skin.
Quantify the usefulness of our design	Prototype testing is currently being performed.
Feedback from potential customers and persons who will utilize the design.	Our point person in Nicaragua, Noel Marin, is highly enthusiastic about our project. We are trying to contact some NICU nurses who can give us some useful insight into catheter infections.
Estimate cost of design	Most of the cost of the test is derived from the chemicals. Stock solutions can be prepared to reduce reagent waste. Since our project makes use of microfluidics, little amount of reagent is necessary.
Defend intellectual property	We will need to research how to do this, as we don’t have any prior experience with patents and other forms of intellectual property defense.
Acknowledge areas of uncertainty in our design	As of now we are uncertain about the sensitivity of our design. Additionally, tests need to be run in order to asses the wicking power of the cotton thread we are employing.

Back to the drawing board

Some concerns were brought up when talking with our instructors that having a bacteria detection system might not have a big impact since 1) we don't have data on UTIs in Nicaragua specifically and 2) the urinary catheter may be hidden under drapes such that the patient might not even know if the catheter is contaminated.

We're currently brainstorming other ways we can redirect the research and materials we have to a device that would have a greater impact on patients in Nicaragua through more awareness of contamination, accountability on the staff's part, and better practices in the hospital.

I came across a study that was done in a "third level" (not sure exactly what this means) pediatrics hospital in Managua, which looked at the two most frequent nosocomial infections there and analyzed the cost that it added to the hospital. Now, I should note that the article is in Spanish, but I got the general ideas of the study. Most importantly, that according to this paper, the two most frequent nosocomial infections in the NICU were pneumonia acquired from mechanical ventilators and bacteriemia (this was in Spanish- is it translated the same to English?) associated with the use of intravascular catheters.

I think it would be amazing for us to use the nososano sticker to tackle one or both of these nosocomial infections. We would still be able to use the chemical detection of bacteria that we already researched a lot about, and this would be something that would be clearly visible to both hospital staff and parents of newborns in the hospitals, such that parents can demand that such medical equipment that is in constant contact with the newborn be disinfected. The study mentioned Serratia marcescens as a major cause of infection, but otherwise didn't seem to go into much detail about bacteria. (That said, it was in Spanish, so I may have missed something).

I know these were both ideas that we brainstormed, but just wanted to share this study because such a project would have an even greater impact than we thought if they can tackle some of the most frequent nosocomial infections.

Thoughts?

~Neta

Concept to Commercialization

Milestone	How Will We Achieve This?
Ability to communicate the usefulness of our design	Through blog posts, design reviews, intra-group discussions
Prove our design is better than current market alternatives	There are no current market alternatives for bacteria detection in urinary catheters.
Understand the setting for the use of our technology	Through our prior visit to Nicaragua over Spring break, and communication with Noel, the microbiologist that we are in contact with in Nicaragua
Proof of the effectiveness of our design	Through previous research done on the chemical tests we are using, through our own tests, and through other people’s experiences with health care and behavior in hospitals in Nicaragua.
Prove that our design is safe	By showing that the chemicals are not harmful to a person or by showing that the chemicals cannot leave the sticker once applied
Quantify the usefulness of our design	By researching the number patients suffering from UTIs and the current sanitary practices when it comes to use of urinary catheters
Feedback from potential customers and persons who will utilize the design.	Talk to as many people as possible in Nicaragua who are in the medical profession.
Estimate cost of design	We will need to determine how much chemical is needed per test, and simply divide the cost of the chemicals by the number of tests that can be produced from that volume. The other materials should not add a significant cost.
Defend intellectual property	We will need to research how to do this, as we don’t have any prior experience with patents and other forms of intellectual property defense
Acknowledge areas of uncertainty in our design	We will get feedback from instructors and peers, so that we don’t overlook important areas in our design.

Implementation of Nososano

1)     Who will use your product?

Post-op patients who require urinary catheters and are at high risk of urinary tract infections. It can also be used on other medical equipment that has prolonged contact with patients, such as equipment in the NICU that is in close contact with babies.

2)     How will you get it to them?

The hospital staff will continue using the urinary catheters that they already have, and simply place the nososano sticker on the designated areas of the apparatus. They can make the stickers themselves using bandaids and chemicals that we will provide them. 

3)     How much will it cost to make (not the prototype - the final product)?

All the chemicals together were just under $100 dollars, and are at a high enough volume to be used for many tests. We will know a more precise number once we do the tests and figure out exactly how much chemical is needed per sticker. 

4)     Where/how will it be manufactured?

It can be prepared in the hospital, in labs, in offices- anywhere and by anyone. Perhaps the maintenance crew can be responsible for preparing the nososano stickers and nurses can place the stickers onto the catheters. 

5)     How will local community members be involved?

Local community members can help enforce better hospital practices and maintenance of urinary catheters, but demanding that hospital staff disinfect catheters more often, especially when the sticker changes color.

Reflections on Nicaraguan news

Hi Team :)

It seems like the main villain in terms of nosocomial infections in Ocotal are Enterobacteria. I did some research and these bacteria are catalase positive and nitrite positive. This is test the other team used two years ago to detect nitrite.

It turns out that Enterobacteria are capable of reducing nitrates to nitrites (which can then be detected by the colorimetric test using the Griess reagent). All the chemicals are fairly non-toxic, so it could be yet another test we could use.

Finally, if catheter acquired UTIs are not a particularly big problem in NicaraguaI think we could target NICU instead. Noel said it was a big problem since these babies don't have a developed immunological system. The form factor is this case would be more straightforward. The "tag" or "sticker" would be visible to the hospital staff but also to the parents, who would make sure something is done is case there is a color change.

Any thoughts?

-Thais

News from Nicaragua

We talked earlier today with Noel Olivas Marlin, who works as a lab technician in Nicaragua. He is responsible for identifying bacteria in a hospital in Ocotal. He provided us with a list of the most common bacteria involved in nosocomial infections. He elaborated by saying that infections are usually developed in immunocompromised patients, specially newborns 0-7 days.

Enterobacterias. Hafnia alvei, Serratia spp.Klebsiella neumoniae Escherichia spp Pantoea agglomerans, Enterobacter cloacae
No fermentadores: Acinetobacter spp, Pseudomonas aeruginosa
Staphylococcus aereus y coagulasa negativa, Streptococcus spp.

-Thais

Bacteria test for Enterobacter (510K)

K082068 - E. coli PNA FISH
K060099 - S. aureus PNA FISH
K902213 - Accuprobe S. aureus culture identification test
Like Neta, the last device had no predicative device listed.

-Thais

more 510k info for catheters

Note: I tried looking for 510k info for indole swab tests and other rapid chemical tests, and there were no summaries. Why is that the case?

Anyway, here is the information I do have from the exercise:

K090262 (PercuCath Urinary Catheter)
-> K002868 (Bardex Lubri-Sil 3-Way Foley Catheter)
---> K984084 (Bardex Lubri-Sil Foley Catheter)
-----> Bardex Lubricath foley catheter (many of the summaries had the names of the predicate devices listed with no 510k  number, which is very frustrating if you want to find out about predicate devices.

~Neta

FDA 510K: Urological Catheters

Dfiner Urological Catheter
K013360

-----Imager Torque Catheter
-----K965229

----------Drainage Catheter, Sialo (Dilation balloon kit and accessories)
----------K072334

-----Imager Urology Torque Catheter
-----K011965

----------K965229 (haha…fail…)

- steph

Most Common UTI-causing bacteria

We've talked about focusing on a small number of bacteria in our detection system. Here are the most common types of bacteria found to cause urinary tract infections (E. coli causes 90% of infections!). Please note that these numbers are in the U.S., so I'm making the assumption that there are similar causes of infections in Nicaragua.
Here's a graph summarizing the search- with the bacteria, and which tests can be used to identify it. Feel free to edit this post and add more tests as this information is from a couple of sources, so it may not be comprehensive.
 

Bacteria	Test
E. coli (90% of UTIs!)	indole test
Staphylococcus saprophyticus  (10-20% of UTIs)	?
Klebsiella	indole test, citrate test
Enterococci	PYR test?
Citrobacter	Citrate test
Proteus mirabilis	Indole negative and Nitrate reductase positive (no gas bubbles produced) Methyl Red positive and Voges-Proskauer negative Catalase positive and Cytochrome Oxidase negative Phenylalanine Deaminase positive Tryptophan test- negative (-) Urea test- positive Casein test-negative Starch test- negative Hydrogen sulfide test- positive Citrate agar test- positive

 ~Neta