Semester 2- Week 10 Kierstin

 In Class: 

We had a team meeting with Dr. Rickard and then with Dr. Gordon. 

We then had our broader impacts discussion where we talked about how every device has a lot of impacts on the world and on people in ways we might not have considered before. 

Lab: 

We did our first surgery simulation this week. We had to take inventory of what tools we had and set up our space before doing the surgery. Brinkley was the note-taker, and Alex and I did the procedure. We used one eye and used two valves to practice the surgery. We also had to put on our PPE before the surgery. 

The valve in the image above is the first valve that we used in the simulation. This was the smallest valve that we had manufactured and we thought it would be a good place to start with the surgery because it would be less complex. We cut off the excess tubes at the end because we are not using the suture resistance design anymore. 

We started with making a conjunctival incision. This was very difficult to do because it was hard to tell the parts of the conjunctiva from the muscles of the eye and extra tissue that was left on from extracting the pig eye. 

After many attempts we were able to start making a pocket for the valve to go into. 

We made a pocket that could fit our valve. The actual procedure would be a little farther back on the eye, but I think this was pretty good for our first attempt. 

We then sutured the valve in place. This was very difficult and we did not do a good job at this. I think we need to watch some suturing videos before attempting this again. We also cut the tube that goes into the eye. We accidentally poked the hole for this in the wrong place, but when we poked another hole we could not get the tube in the eye because the needle we made the hole with was too small. We have bigger needles ordered, so hopefully, that will help next time. 

 

This is an image of our first attempt. 

We then tried again with a larger valve because we knew that our design was much bigger than the one we just used. 

We made a cleaner and bigger pocket this time around which was good. We just started working on a different quadrant of the eye. 

We inserted the valve and sutured it in place. This process was definitely improved since the first attempt. 

We then had to disinfect everything and clean our space. We disposed of the pig eye and accidentally threw away our valves too. 

This week we had to do Deliverable 7: 

This included writing test protocols for specs that needed to be met by our products. 

Manufacturing: 

This week consisted of a lot of manufacturing. Brinkley and I manufactured the new and final prototype. This took a couple of days because the epoxy layers and precision that had to be done. We also manufactured practice valves for the surgery implantation so we do not waste valves that actually work. In these pictures, you can see the baerveldt-sized bases that I first cut from a previous valve and then thinner ones that we poured. You can also see the lab setup and labeling that we did to test the Ahmed resistors before using them in the new valve. In the second picture, you can see the orientation of the numbered resistors in order to know which one is where. We tested all the valves and recorded the heights that they first started to leak. In the last few pictures, you can see the flat baerveldt plates that we will use for surgery simulations and the epoxy mold we used to make them. We glued the tubing on the plate for the surgery simulation (second to last picture).

We tested the final prototype and all the ahmed resistors leaked which was a good thing. Meaning that we manufactured it well. Two of the valves needed more pressure than the first one, but this could be because of an internal blockage of some type. It is minimal which is good.

Meeting with Dr. Rickard: 

We talked about frozen eyes and how to defrost them. We need to label the bag. We learned that we should have separated the eyes before freezing them because now they are all frozen together. There is also an eye demonstration for a tour tomorrow we will be using the eyes to demonstrate eye pressure and flow sensors.