Capstone Week 7

Week 7:

In class:

This week in class, all the groups presented their projects. We started with the exoskeleton group, then the glaucoma group, the memory shape polymer group, and lastly the children's sports equipment group. It was really interesting to hear what everyone was working on and the problems we are trying to find solutions to.

A brief meeting with Dr. Rickard: 

On Thursday morning Dr. Rickard stopped by my desk and went over a few design concepts with me and suggested that I look into contacting new worlds supplier to see if we can get some silicone samples. 

He also liked our concept of an expanding tube and did not think that we need a pin to hold it open. He suggested that something to think about would be redirecting the flow outputs. These are his notes from the meeting.

I looked up who could be new worlds' supplier, and this was the most likely supplier.

After doing this research I talked with Alex and she said she could contact them to see if they could send us any samples for our project. 

Benchtop Testing and Shakedowns: 

This week also consisted of a lot of benchtop testing and performing shakedown tests, shown below. 

First, we added the pressure sensors to the system which will measure the pressure before and after the glaucoma valve. Fady is figuring out how to use them on other sensors, but soon he will be able to read the pressures in our system.

Then, we brainstormed how to create the fibrosis-enclosed system. We had tubing big enough to put the valve in, but we needed air-tight connectors, so we cut some one-way valves that we planned to wedge inside the tubing to create the seal. (This was very hard to cut.) We ordered pouches to use in the future, but this will work for now.

We had to put the valve through the opening of the cut connector, and then put a tube over that to create another seal. We ended up having to try two different types of glue shown below because the cement glue didn’t adhere fast enough for our test. 

This glued portion, shown above, ended up not holding either, so we had to find a different connector for the tubing. 

Pictured above is the glaucoma valve that will be put inside the “fibrosis tubing.” We had to do all the purging of these systems underwater because they were not yet enclosed, but we could not have any air in there.

This is the valve inside the enclosed and purged fibrosis tubing, and the new tubing connector is the white thing.

A huge problem we encountered was purging out air bubbles from the different components. This took up a lot of the testing time, and as mentioned above, it had to be done underwater which created a big challenge.

Our flow sensor should have read 0, but this was the smallest we could get it to, so we just have to average our values and factor in this error when recording our data. 

This is the space we did our benchtop testing in. 

Team Benchtop:

When the team was all together Fady worked on the electrical component and Alex helped Brinkley and me with another test. We wanted to test the resistor/ tubing stretch idea, shown in my new design. 

First I used a scalpel to cut one side of the tubing thinner, so it would be the side to stretch and let the water through when pressure was added from the syringe. This ended up not impacting where the flow came out of the blocked tube. 

We then tested with tubing that was not cut and with enough pressure from the syringe we got the leakage we wanted. Our next steps are to try this with different tubing, resistors, and tubing with resistors in parallel. 

A new design was drawn up, and shakedown protocol:

I drew up a new design based on my conversation with Dr. Rickard, and I also thought through a shakedown test to test the concept of the resistors in parallel. The new design does not need a pin to keep the tube open because the tube is stretched and is dependent on atm pressure, not the fibrosis pressure after the resistor. This can be tested Next week, or during capstone time. 

Next week's Prep: 

I updated Jira for the next week's team and individual assignments. 

Ethics topic: 

Earlier in the week, I emailed Dr. Gordon about doing CRISPR for my ethics topic. He said someone was already doing that so I asked if I could do CRISPER based on the cost and availability. He never replied and confirmed whether I could do this or not, so I am still not sure what my topic will be. 

This is my second choice for a topic, and I am waiting on a response. Centurion Medical Products Recalls Airway Kit containing Sheridan® Endotracheal Tubes Due to Potential for the Tube Connector to Dislodge, Which May Result in Disconnection of the Patient from the Breathing Circuit.